Rename protobuf Ruby module to google/protobuf and rework its build

system. The Ruby module build now uses an amalgamated distribution of
upb, and successfully builds a Ruby gem called 'google-protobuf' with
module 'google/protobuf'.

1 files changed, 7439 insertions, 0 deletions

diff --git a/ruby/ext/google/protobuf_c/upb.h b/ruby/ext/google/protobuf_c/upb.h
new file mode 100644
index 00000000..150aef10
--- /dev/null
+++ b/ruby/ext/google/protobuf_c/upb.h
@@ -0,0 +1,7439 @@
+// Amalgamated source file
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009-2012 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * Defs are upb's internal representation of the constructs that can appear
+ * in a .proto file:
+ *
+ * - upb_msgdef: describes a "message" construct.
+ * - upb_fielddef: describes a message field.
+ * - upb_enumdef: describes an enum.
+ * (TODO: definitions of services).
+ *
+ * Like upb_refcounted objects, defs are mutable only until frozen, and are
+ * only thread-safe once frozen.
+ *
+ * This is a mixed C/C++ interface that offers a full API to both languages.
+ * See the top-level README for more information.
+ */
+
+#ifndef UPB_DEF_H_
+#define UPB_DEF_H_
+
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009-2012 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * A refcounting scheme that supports circular refs.  It accomplishes this by
+ * partitioning the set of objects into groups such that no cycle spans groups;
+ * we can then reference-count the group as a whole and ignore refs within the
+ * group.  When objects are mutable, these groups are computed very
+ * conservatively; we group any objects that have ever had a link between them.
+ * When objects are frozen, we compute strongly-connected components which
+ * allows us to be precise and only group objects that are actually cyclic.
+ *
+ * This is a mixed C/C++ interface that offers a full API to both languages.
+ * See the top-level README for more information.
+ */
+
+#ifndef UPB_REFCOUNTED_H_
+#define UPB_REFCOUNTED_H_
+
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * This header is INTERNAL-ONLY!  Its interfaces are not public or stable!
+ * This file defines very fast int->upb_value (inttable) and string->upb_value
+ * (strtable) hash tables.
+ *
+ * The table uses chained scatter with Brent's variation (inspired by the Lua
+ * implementation of hash tables).  The hash function for strings is Austin
+ * Appleby's "MurmurHash."
+ *
+ * The inttable uses uintptr_t as its key, which guarantees it can be used to
+ * store pointers or integers of at least 32 bits (upb isn't really useful on
+ * systems where sizeof(void*) < 4).
+ *
+ * The table must be homogenous (all values of the same type).  In debug
+ * mode, we check this on insert and lookup.
+ */
+
+#ifndef UPB_TABLE_H_
+#define UPB_TABLE_H_
+
+#include <assert.h>
+#include <stdint.h>
+#include <string.h>
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * This file contains shared definitions that are widely used across upb.
+ *
+ * This is a mixed C/C++ interface that offers a full API to both languages.
+ * See the top-level README for more information.
+ */
+
+#ifndef UPB_H_
+#define UPB_H_
+
+#include <assert.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+// inline if possible, emit standalone code if required.
+#ifdef __cplusplus
+#define UPB_INLINE inline
+#else
+#define UPB_INLINE static inline
+#endif
+
+#if __STDC_VERSION__ >= 199901L
+#define UPB_C99
+#endif
+
+#if ((defined(__cplusplus) && __cplusplus >= 201103L) || \
+      defined(__GXX_EXPERIMENTAL_CXX0X__)) && !defined(UPB_NO_CXX11)
+#define UPB_CXX11
+#endif
+
+#ifdef UPB_CXX11
+#include <type_traits>
+#define UPB_DISALLOW_COPY_AND_ASSIGN(class_name) \
+  class_name(const class_name&) = delete; \
+  void operator=(const class_name&) = delete;
+#define UPB_DISALLOW_POD_OPS(class_name, full_class_name) \
+  class_name() = delete; \
+  ~class_name() = delete; \
+  /* Friend Pointer<T> so it can access base class. */ \
+  friend class Pointer<full_class_name>; \
+  friend class Pointer<const full_class_name>; \
+  UPB_DISALLOW_COPY_AND_ASSIGN(class_name)
+#define UPB_ASSERT_STDLAYOUT(type) \
+  static_assert(std::is_standard_layout<type>::value, \
+                #type " must be standard layout");
+#else  // !defined(UPB_CXX11)
+#define UPB_DISALLOW_COPY_AND_ASSIGN(class_name) \
+  class_name(const class_name&); \
+  void operator=(const class_name&);
+#define UPB_DISALLOW_POD_OPS(class_name, full_class_name) \
+  class_name(); \
+  ~class_name(); \
+  /* Friend Pointer<T> so it can access base class. */ \
+  friend class Pointer<full_class_name>; \
+  friend class Pointer<const full_class_name>; \
+  UPB_DISALLOW_COPY_AND_ASSIGN(class_name)
+#define UPB_ASSERT_STDLAYOUT(type)
+#endif
+
+
+#ifdef __cplusplus
+
+#define UPB_PRIVATE_FOR_CPP private:
+#define UPB_DECLARE_TYPE(cppname, cname) typedef cppname cname;
+#define UPB_BEGIN_EXTERN_C extern "C" {
+#define UPB_END_EXTERN_C }
+#define UPB_DEFINE_STRUCT0(cname, members) members;
+#define UPB_DEFINE_STRUCT(cname, cbase, members) \
+ public:                                         \
+  cbase* base() { return &base_; }               \
+  const cbase* base() const { return &base_; }   \
+                                                 \
+ private:                                        \
+  cbase base_;                                   \
+  members;
+#define UPB_DEFINE_CLASS0(cppname, cppmethods, members) \
+  class cppname {                                      \
+    cppmethods                                         \
+    members                                            \
+  };                                                   \
+  UPB_ASSERT_STDLAYOUT(cppname);
+#define UPB_DEFINE_CLASS1(cppname, cppbase, cppmethods, members)   \
+  UPB_DEFINE_CLASS0(cppname, cppmethods, members)                  \
+  namespace upb {                                                 \
+  template <>                                                     \
+  class Pointer<cppname> : public PointerBase<cppname, cppbase> { \
+   public:                                                        \
+    explicit Pointer(cppname* ptr) : PointerBase(ptr) {}          \
+  };                                                              \
+  template <>                                                     \
+  class Pointer<const cppname>                                    \
+      : public PointerBase<const cppname, const cppbase> {        \
+   public:                                                        \
+    explicit Pointer(const cppname* ptr) : PointerBase(ptr) {}    \
+  };                                                              \
+  }
+#define UPB_DEFINE_CLASS2(cppname, cppbase, cppbase2, cppmethods, members)    \
+  UPB_DEFINE_CLASS0(cppname, UPB_QUOTE(cppmethods), members)                  \
+  namespace upb {                                                            \
+  template <>                                                                \
+  class Pointer<cppname> : public PointerBase2<cppname, cppbase, cppbase2> { \
+   public:                                                                   \
+    explicit Pointer(cppname* ptr) : PointerBase2(ptr) {}                    \
+  };                                                                         \
+  template <>                                                                \
+  class Pointer<const cppname>                                               \
+      : public PointerBase2<const cppname, const cppbase, const cppbase2> {  \
+   public:                                                                   \
+    explicit Pointer(const cppname* ptr) : PointerBase2(ptr) {}              \
+  };                                                                         \
+  }
+
+#else  // !defined(__cplusplus)
+
+#define UPB_PRIVATE_FOR_CPP
+#define UPB_DECLARE_TYPE(cppname, cname) \
+  struct cname;                          \
+  typedef struct cname cname;
+#define UPB_BEGIN_EXTERN_C
+#define UPB_END_EXTERN_C
+#define UPB_DEFINE_STRUCT0(cname, members) \
+  struct cname {                           \
+    members;                               \
+  };
+#define UPB_DEFINE_STRUCT(cname, cbase, members) \
+  struct cname {                                 \
+    cbase base;                                  \
+    members;                                     \
+  };
+#define UPB_DEFINE_CLASS0(cppname, cppmethods, members) members
+#define UPB_DEFINE_CLASS1(cppname, cppbase, cppmethods, members) members
+#define UPB_DEFINE_CLASS2(cppname, cppbase, cppbase2, cppmethods, members) \
+  members
+
+#endif  // defined(__cplusplus)
+
+#ifdef __GNUC__
+#define UPB_NORETURN __attribute__((__noreturn__))
+#else
+#define UPB_NORETURN
+#endif
+
+#define UPB_MAX(x, y) ((x) > (y) ? (x) : (y))
+#define UPB_MIN(x, y) ((x) < (y) ? (x) : (y))
+
+#define UPB_UNUSED(var) (void)var
+
+// Code with commas confuses the preprocessor when passed as arguments, whether
+// C++ type names with commas (eg. Foo<int, int>) or code blocks that declare
+// variables (ie. int foo, bar).
+#define UPB_QUOTE(...) __VA_ARGS__
+
+// For asserting something about a variable when the variable is not used for
+// anything else.  This prevents "unused variable" warnings when compiling in
+// debug mode.
+#define UPB_ASSERT_VAR(var, predicate) UPB_UNUSED(var); assert(predicate)
+
+// Generic function type.
+typedef void upb_func();
+
+/* Casts **********************************************************************/
+
+// Upcasts for C.  For downcasts see the definitions of the subtypes.
+#define UPB_UPCAST(obj) (&(obj)->base)
+#define UPB_UPCAST2(obj) UPB_UPCAST(UPB_UPCAST(obj))
+
+#ifdef __cplusplus
+
+// Downcasts for C++.  We can't use C++ inheritance directly and maintain
+// compatibility with C.  So our inheritance is undeclared in C++.
+// Specializations of these casting functions are defined for appropriate type
+// pairs, and perform the necessary checks.
+//
+// Example:
+//   upb::Def* def = <...>;
+//   upb::MessageDef* = upb::dyn_cast<upb::MessageDef*>(def);
+
+namespace upb {
+
+// Casts to a direct subclass.  The caller must know that cast is correct; an
+// incorrect cast will throw an assertion failure in debug mode.
+template<class To, class From> To down_cast(From* f);
+
+// Casts to a direct subclass.  If the class does not actually match the given
+// subtype, returns NULL.
+template<class To, class From> To dyn_cast(From* f);
+
+// Pointer<T> is a simple wrapper around a T*.  It is only constructed for
+// upcast() below, and its sole purpose is to be implicitly convertable to T* or
+// pointers to base classes, just as a pointer would be in regular C++ if the
+// inheritance were directly expressed as C++ inheritance.
+template <class T> class Pointer;
+
+// Casts to any base class, or the type itself (ie. can be a no-op).
+template <class T> inline Pointer<T> upcast(T *f) { return Pointer<T>(f); }
+
+template <class T, class Base>
+class PointerBase {
+ public:
+  explicit PointerBase(T* ptr) : ptr_(ptr) {}
+  operator T*() { return ptr_; }
+  operator Base*() { return ptr_->base(); }
+
+ private:
+  T* ptr_;
+};
+
+template <class T, class Base, class Base2>
+class PointerBase2 : public PointerBase<T, Base> {
+ public:
+  explicit PointerBase2(T* ptr) : PointerBase<T, Base>(ptr) {}
+  operator Base2*() { return Pointer<Base>(*this); }
+};
+
+}
+
+#endif
+
+
+/* upb::reffed_ptr ************************************************************/
+
+#ifdef __cplusplus
+
+#include <algorithm>  // For std::swap().
+
+namespace upb {
+
+// Provides RAII semantics for upb refcounted objects.  Each reffed_ptr owns a
+// ref on whatever object it points to (if any).
+template <class T> class reffed_ptr {
+ public:
+  reffed_ptr() : ptr_(NULL) {}
+
+  // If ref_donor is NULL, takes a new ref, otherwise adopts from ref_donor.
+  template <class U>
+  reffed_ptr(U* val, const void* ref_donor = NULL)
+      : ptr_(upb::upcast(val)) {
+    if (ref_donor) {
+      assert(ptr_);
+      ptr_->DonateRef(ref_donor, this);
+    } else if (ptr_) {
+      ptr_->Ref(this);
+    }
+  }
+
+  template <class U>
+  reffed_ptr(const reffed_ptr<U>& other)
+      : ptr_(upb::upcast(other.get())) {
+    if (ptr_) ptr_->Ref(this);
+  }
+
+  ~reffed_ptr() { if (ptr_) ptr_->Unref(this); }
+
+  template <class U>
+  reffed_ptr& operator=(const reffed_ptr<U>& other) {
+    reset(other.get());
+    return *this;
+  }
+
+  reffed_ptr& operator=(const reffed_ptr& other) {
+    reset(other.get());
+    return *this;
+  }
+
+  // TODO(haberman): add C++11 move construction/assignment for greater
+  // efficiency.
+
+  void swap(reffed_ptr& other) {
+    if (ptr_ == other.ptr_) {
+      return;
+    }
+
+    if (ptr_) ptr_->DonateRef(this, &other);
+    if (other.ptr_) other.ptr_->DonateRef(&other, this);
+    std::swap(ptr_, other.ptr_);
+  }
+
+  T& operator*() const {
+    assert(ptr_);
+    return *ptr_;
+  }
+
+  T* operator->() const {
+    assert(ptr_);
+    return ptr_;
+  }
+
+  T* get() const { return ptr_; }
+
+  // If ref_donor is NULL, takes a new ref, otherwise adopts from ref_donor.
+  template <class U>
+  void reset(U* ptr = NULL, const void* ref_donor = NULL) {
+    reffed_ptr(ptr, ref_donor).swap(*this);
+  }
+
+  template <class U>
+  reffed_ptr<U> down_cast() {
+    return reffed_ptr<U>(upb::down_cast<U*>(get()));
+  }
+
+  template <class U>
+  reffed_ptr<U> dyn_cast() {
+    return reffed_ptr<U>(upb::dyn_cast<U*>(get()));
+  }
+
+  // Plain release() is unsafe; if we were the only owner, it would leak the
+  // object.  Instead we provide this:
+  T* ReleaseTo(const void* new_owner) {
+    T* ret = NULL;
+    ptr_->DonateRef(this, new_owner);
+    std::swap(ret, ptr_);
+    return ret;
+  }
+
+ private:
+  T* ptr_;
+};
+
+}  // namespace upb
+
+#endif  // __cplusplus
+
+
+/* upb::Status ****************************************************************/
+
+#ifdef __cplusplus
+namespace upb {
+class ErrorSpace;
+class Status;
+}
+#endif
+
+UPB_DECLARE_TYPE(upb::ErrorSpace, upb_errorspace);
+UPB_DECLARE_TYPE(upb::Status, upb_status);
+
+// The maximum length of an error message before it will get truncated.
+#define UPB_STATUS_MAX_MESSAGE 128
+
+// An error callback function is used to report errors from some component.
+// The function can return "true" to indicate that the component should try
+// to recover and proceed, but this is not always possible.
+typedef bool upb_errcb_t(void *closure, const upb_status* status);
+
+UPB_DEFINE_CLASS0(upb::ErrorSpace,
+,
+UPB_DEFINE_STRUCT0(upb_errorspace,
+  const char *name;
+  // Should the error message in the status object according to this code.
+  void (*set_message)(upb_status* status, int code);
+));
+
+// Object representing a success or failure status.
+// It owns no resources and allocates no memory, so it should work
+// even in OOM situations.
+UPB_DEFINE_CLASS0(upb::Status,
+ public:
+  Status();
+
+  // Returns true if there is no error.
+  bool ok() const;
+
+  // Optional error space and code, useful if the caller wants to
+  // programmatically check the specific kind of error.
+  ErrorSpace* error_space();
+  int code() const;
+
+  const char *error_message() const;
+
+  // The error message will be truncated if it is longer than
+  // UPB_STATUS_MAX_MESSAGE-4.
+  void SetErrorMessage(const char* msg);
+  void SetFormattedErrorMessage(const char* fmt, ...);
+
+  // If there is no error message already, this will use the ErrorSpace to
+  // populate the error message for this code.  The caller can still call
+  // SetErrorMessage() to give a more specific message.
+  void SetErrorCode(ErrorSpace* space, int code);
+
+  // Resets the status to a successful state with no message.
+  void Clear();
+
+  void CopyFrom(const Status& other);
+
+ private:
+  UPB_DISALLOW_COPY_AND_ASSIGN(Status);
+,
+UPB_DEFINE_STRUCT0(upb_status,
+  bool ok_;
+
+  // Specific status code defined by some error space (optional).
+  int code_;
+  upb_errorspace *error_space_;
+
+  // Error message; NULL-terminated.
+  char msg[UPB_STATUS_MAX_MESSAGE];
+));
+
+#define UPB_STATUS_INIT {true, 0, NULL, {0}}
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// The returned string is invalidated by any other call into the status.
+const char *upb_status_errmsg(const upb_status *status);
+bool upb_ok(const upb_status *status);
+upb_errorspace *upb_status_errspace(const upb_status *status);
+int upb_status_errcode(const upb_status *status);
+
+// Any of the functions that write to a status object allow status to be NULL,
+// to support use cases where the function's caller does not care about the
+// status message.
+void upb_status_clear(upb_status *status);
+void upb_status_seterrmsg(upb_status *status, const char *msg);
+void upb_status_seterrf(upb_status *status, const char *fmt, ...);
+void upb_status_vseterrf(upb_status *status, const char *fmt, va_list args);
+void upb_status_seterrcode(upb_status *status, upb_errorspace *space, int code);
+void upb_status_copy(upb_status *to, const upb_status *from);
+
+#ifdef __cplusplus
+}  // extern "C"
+
+namespace upb {
+
+// C++ Wrappers
+inline Status::Status() { Clear(); }
+inline bool Status::ok() const { return upb_ok(this); }
+inline const char* Status::error_message() const {
+  return upb_status_errmsg(this);
+}
+inline void Status::SetErrorMessage(const char* msg) {
+  upb_status_seterrmsg(this, msg);
+}
+inline void Status::SetFormattedErrorMessage(const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  upb_status_vseterrf(this, fmt, args);
+  va_end(args);
+}
+inline void Status::SetErrorCode(ErrorSpace* space, int code) {
+  upb_status_seterrcode(this, space, code);
+}
+inline void Status::Clear() { upb_status_clear(this); }
+inline void Status::CopyFrom(const Status& other) {
+  upb_status_copy(this, &other);
+}
+
+}  // namespace upb
+
+#endif
+
+#endif  /* UPB_H_ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/* upb_value ******************************************************************/
+
+// A tagged union (stored untagged inside the table) so that we can check that
+// clients calling table accessors are correctly typed without having to have
+// an explosion of accessors.
+typedef enum {
+  UPB_CTYPE_INT32    = 1,
+  UPB_CTYPE_INT64    = 2,
+  UPB_CTYPE_UINT32   = 3,
+  UPB_CTYPE_UINT64   = 4,
+  UPB_CTYPE_BOOL     = 5,
+  UPB_CTYPE_CSTR     = 6,
+  UPB_CTYPE_PTR      = 7,
+  UPB_CTYPE_CONSTPTR = 8,
+  UPB_CTYPE_FPTR     = 9,
+} upb_ctype_t;
+
+typedef union {
+  int32_t  int32;
+  int64_t  int64;
+  uint64_t uint64;
+  uint32_t uint32;
+  bool     _bool;
+  char     *cstr;
+  void     *ptr;
+  const void *constptr;
+  upb_func *fptr;
+} _upb_value;
+
+typedef struct {
+  _upb_value val;
+#ifndef NDEBUG
+  // In debug mode we carry the value type around also so we can check accesses
+  // to be sure the right member is being read.
+  upb_ctype_t ctype;
+#endif
+} upb_value;
+
+#ifdef UPB_C99
+#define UPB_VALUE_INIT(v, member) {.member = v}
+#endif
+#define UPB__VALUE_INIT_NONE      UPB_VALUE_INIT(NULL, ptr)
+
+#ifdef NDEBUG
+#define SET_TYPE(dest, val)      UPB_UNUSED(val)
+#define UPB_VALUE_INIT_NONE      {UPB__VALUE_INIT_NONE}
+#else
+#define SET_TYPE(dest, val) dest = val
+// Non-existent type, all reads will fail.
+#define UPB_VALUE_INIT_NONE      {UPB__VALUE_INIT_NONE, -1}
+#endif
+
+#define UPB_VALUE_INIT_INT32(v)  UPB_VALUE_INIT(v, int32)
+#define UPB_VALUE_INIT_INT64(v)  UPB_VALUE_INIT(v, int64)
+#define UPB_VALUE_INIT_UINT32(v) UPB_VALUE_INIT(v, uint32)
+#define UPB_VALUE_INIT_UINT64(v) UPB_VALUE_INIT(v, uint64)
+#define UPB_VALUE_INIT_BOOL(v)   UPB_VALUE_INIT(v, _bool)
+#define UPB_VALUE_INIT_CSTR(v)   UPB_VALUE_INIT(v, cstr)
+#define UPB_VALUE_INIT_PTR(v)    UPB_VALUE_INIT(v, ptr)
+#define UPB_VALUE_INIT_CONSTPTR(v) UPB_VALUE_INIT(v, constptr)
+#define UPB_VALUE_INIT_FPTR(v)   UPB_VALUE_INIT(v, fptr)
+
+// Like strdup(), which isn't always available since it's not ANSI C.
+char *upb_strdup(const char *s);
+
+UPB_INLINE void _upb_value_setval(upb_value *v, _upb_value val,
+                                  upb_ctype_t ctype) {
+  v->val = val;
+  SET_TYPE(v->ctype, ctype);
+}
+
+UPB_INLINE upb_value _upb_value_val(_upb_value val, upb_ctype_t ctype) {
+  upb_value ret;
+  _upb_value_setval(&ret, val, ctype);
+  return ret;
+}
+
+// For each value ctype, define the following set of functions:
+//
+// // Get/set an int32 from a upb_value.
+// int32_t upb_value_getint32(upb_value val);
+// void upb_value_setint32(upb_value *val, int32_t cval);
+//
+// // Construct a new upb_value from an int32.
+// upb_value upb_value_int32(int32_t val);
+#define FUNCS(name, membername, type_t, proto_type) \
+  UPB_INLINE void upb_value_set ## name(upb_value *val, type_t cval) { \
+    val->val.uint64 = 0; \
+    SET_TYPE(val->ctype, proto_type); \
+    val->val.membername = cval; \
+  } \
+  UPB_INLINE upb_value upb_value_ ## name(type_t val) { \
+    upb_value ret; \
+    upb_value_set ## name(&ret, val); \
+    return ret; \
+  } \
+  UPB_INLINE type_t upb_value_get ## name(upb_value val) { \
+    assert(val.ctype == proto_type); \
+    return val.val.membername; \
+  }
+
+FUNCS(int32,    int32,        int32_t,      UPB_CTYPE_INT32);
+FUNCS(int64,    int64,        int64_t,      UPB_CTYPE_INT64);
+FUNCS(uint32,   uint32,       uint32_t,     UPB_CTYPE_UINT32);
+FUNCS(uint64,   uint64,       uint64_t,     UPB_CTYPE_UINT64);
+FUNCS(bool,     _bool,        bool,         UPB_CTYPE_BOOL);
+FUNCS(cstr,     cstr,         char*,        UPB_CTYPE_CSTR);
+FUNCS(ptr,      ptr,          void*,        UPB_CTYPE_PTR);
+FUNCS(constptr, constptr,     const void*,  UPB_CTYPE_CONSTPTR);
+FUNCS(fptr,     fptr,         upb_func*,    UPB_CTYPE_FPTR);
+
+#undef FUNCS
+
+
+/* upb_table ******************************************************************/
+
+typedef union {
+  uintptr_t num;
+  const char *str;  // We own, nullz.
+} upb_tabkey;
+
+#define UPB_TABKEY_NUM(n) {n}
+#ifdef UPB_C99
+#define UPB_TABKEY_STR(s) {.str = s}
+#endif
+// TODO(haberman): C++
+#define UPB_TABKEY_NONE {0}
+
+typedef struct _upb_tabent {
+  upb_tabkey key;
+  _upb_value val;
+  // Internal chaining.  This is const so we can create static initializers for
+  // tables.  We cast away const sometimes, but *only* when the containing
+  // upb_table is known to be non-const.  This requires a bit of care, but
+  // the subtlety is confined to table.c.
+  const struct _upb_tabent *next;
+} upb_tabent;
+
+typedef struct {
+  size_t count;          // Number of entries in the hash part.
+  size_t mask;           // Mask to turn hash value -> bucket.
+  upb_ctype_t ctype;     // Type of all values.
+  uint8_t size_lg2;      // Size of the hash table part is 2^size_lg2 entries.
+
+  // Hash table entries.
+  // Making this const isn't entirely accurate; what we really want is for it to
+  // have the same const-ness as the table it's inside.  But there's no way to
+  // declare that in C.  So we have to make it const so that we can statically
+  // initialize const hash tables.  Then we cast away const when we have to.
+  const upb_tabent *entries;
+} upb_table;
+
+typedef struct {
+  upb_table t;
+} upb_strtable;
+
+#define UPB_STRTABLE_INIT(count, mask, ctype, size_lg2, entries) \
+  {{count, mask, ctype, size_lg2, entries}}
+
+typedef struct {
+  upb_table t;              // For entries that don't fit in the array part.
+  const _upb_value *array;  // Array part of the table.  See const note above.
+  size_t array_size;        // Array part size.
+  size_t array_count;       // Array part number of elements.
+} upb_inttable;
+
+#define UPB_INTTABLE_INIT(count, mask, ctype, size_lg2, ent, a, asize, acount) \
+  {{count, mask, ctype, size_lg2, ent}, a, asize, acount}
+
+#define UPB_EMPTY_INTTABLE_INIT(ctype) \
+  UPB_INTTABLE_INIT(0, 0, ctype, 0, NULL, NULL, 0, 0)
+
+#define UPB_ARRAY_EMPTYVAL -1
+#define UPB_ARRAY_EMPTYENT UPB_VALUE_INIT_INT64(UPB_ARRAY_EMPTYVAL)
+
+UPB_INLINE size_t upb_table_size(const upb_table *t) {
+  if (t->size_lg2 == 0)
+    return 0;
+  else
+    return 1 << t->size_lg2;
+}
+
+// Internal-only functions, in .h file only out of necessity.
+UPB_INLINE bool upb_tabent_isempty(const upb_tabent *e) {
+  return e->key.num == 0;
+}
+
+// Used by some of the unit tests for generic hashing functionality.
+uint32_t MurmurHash2(const void * key, size_t len, uint32_t seed);
+
+UPB_INLINE upb_tabkey upb_intkey(uintptr_t key) {
+  upb_tabkey k;
+  k.num = key;
+  return k;
+}
+
+UPB_INLINE uint32_t upb_inthash(uintptr_t key) {
+  return (uint32_t)key;
+}
+
+static const upb_tabent *upb_getentry(const upb_table *t, uint32_t hash) {
+  return t->entries + (hash & t->mask);
+}
+
+UPB_INLINE bool upb_arrhas(_upb_value v) {
+  return v.uint64 != (uint64_t)UPB_ARRAY_EMPTYVAL;
+}
+
+// Initialize and uninitialize a table, respectively.  If memory allocation
+// failed, false is returned that the table is uninitialized.
+bool upb_inttable_init(upb_inttable *table, upb_ctype_t ctype);
+bool upb_strtable_init(upb_strtable *table, upb_ctype_t ctype);
+void upb_inttable_uninit(upb_inttable *table);
+void upb_strtable_uninit(upb_strtable *table);
+
+// Returns the number of values in the table.
+size_t upb_inttable_count(const upb_inttable *t);
+UPB_INLINE size_t upb_strtable_count(const upb_strtable *t) {
+  return t->t.count;
+}
+
+// Inserts the given key into the hashtable with the given value.  The key must
+// not already exist in the hash table.  For string tables, the key must be
+// NULL-terminated, and the table will make an internal copy of the key.
+// Inttables must not insert a value of UINTPTR_MAX.
+//
+// If a table resize was required but memory allocation failed, false is
+// returned and the table is unchanged.
+bool upb_inttable_insert(upb_inttable *t, uintptr_t key, upb_value val);
+bool upb_strtable_insert(upb_strtable *t, const char *key, upb_value val);
+
+// Looks up key in this table, returning "true" if the key was found.
+// If v is non-NULL, copies the value for this key into *v.
+bool upb_inttable_lookup(const upb_inttable *t, uintptr_t key, upb_value *v);
+bool upb_strtable_lookup2(const upb_strtable *t, const char *key, size_t len,
+                          upb_value *v);
+
+// For NULL-terminated strings.
+UPB_INLINE bool upb_strtable_lookup(const upb_strtable *t, const char *key,
+                                    upb_value *v) {
+  return upb_strtable_lookup2(t, key, strlen(key), v);
+}
+
+// Removes an item from the table.  Returns true if the remove was successful,
+// and stores the removed item in *val if non-NULL.
+bool upb_inttable_remove(upb_inttable *t, uintptr_t key, upb_value *val);
+bool upb_strtable_remove(upb_strtable *t, const char *key, upb_value *val);
+
+// Updates an existing entry in an inttable.  If the entry does not exist,
+// returns false and does nothing.  Unlike insert/remove, this does not
+// invalidate iterators.
+bool upb_inttable_replace(upb_inttable *t, uintptr_t key, upb_value val);
+
+// Handy routines for treating an inttable like a stack.  May not be mixed with
+// other insert/remove calls.
+bool upb_inttable_push(upb_inttable *t, upb_value val);
+upb_value upb_inttable_pop(upb_inttable *t);
+
+// Convenience routines for inttables with pointer keys.
+bool upb_inttable_insertptr(upb_inttable *t, const void *key, upb_value val);
+bool upb_inttable_removeptr(upb_inttable *t, const void *key, upb_value *val);
+bool upb_inttable_lookupptr(
+    const upb_inttable *t, const void *key, upb_value *val);
+
+// Optimizes the table for the current set of entries, for both memory use and
+// lookup time.  Client should call this after all entries have been inserted;
+// inserting more entries is legal, but will likely require a table resize.
+void upb_inttable_compact(upb_inttable *t);
+
+// A special-case inlinable version of the lookup routine for 32-bit integers.
+UPB_INLINE bool upb_inttable_lookup32(const upb_inttable *t, uint32_t key,
+                                      upb_value *v) {
+  *v = upb_value_int32(0);  // Silence compiler warnings.
+  if (key < t->array_size) {
+    _upb_value arrval = t->array[key];
+    if (upb_arrhas(arrval)) {
+      _upb_value_setval(v, arrval, t->t.ctype);
+      return true;
+    } else {
+      return false;
+    }
+  } else {
+    const upb_tabent *e;
+    if (t->t.entries == NULL) return false;
+    for (e = upb_getentry(&t->t, upb_inthash(key)); true; e = e->next) {
+      if ((uint32_t)e->key.num == key) {
+        _upb_value_setval(v, e->val, t->t.ctype);
+        return true;
+      }
+      if (e->next == NULL) return false;
+    }
+  }
+}
+
+// Exposed for testing only.
+bool upb_strtable_resize(upb_strtable *t, size_t size_lg2);
+
+/* Iterators ******************************************************************/
+
+// Iterators for int and string tables.  We are subject to some kind of unusual
+// design constraints:
+//
+// For high-level languages:
+//  - we must be able to guarantee that we don't crash or corrupt memory even if
+//    the program accesses an invalidated iterator.
+//
+// For C++11 range-based for:
+//  - iterators must be copyable
+//  - iterators must be comparable
+//  - it must be possible to construct an "end" value.
+//
+// Iteration order is undefined.
+//
+// Modifying the table invalidates iterators.  upb_{str,int}table_done() is
+// guaranteed to work even on an invalidated iterator, as long as the table it
+// is iterating over has not been freed.  Calling next() or accessing data from
+// an invalidated iterator yields unspecified elements from the table, but it is
+// guaranteed not to crash and to return real table elements (except when done()
+// is true).
+
+
+/* upb_strtable_iter **********************************************************/
+
+//   upb_strtable_iter i;
+//   upb_strtable_begin(&i, t);
+//   for(; !upb_strtable_done(&i); upb_strtable_next(&i)) {
+//     const char *key = upb_strtable_iter_key(&i);
+//     const upb_value val = upb_strtable_iter_value(&i);
+//     // ...
+//   }
+
+typedef struct {
+  const upb_strtable *t;
+  size_t index;
+} upb_strtable_iter;
+
+void upb_strtable_begin(upb_strtable_iter *i, const upb_strtable *t);
+void upb_strtable_next(upb_strtable_iter *i);
+bool upb_strtable_done(const upb_strtable_iter *i);
+const char *upb_strtable_iter_key(upb_strtable_iter *i);
+upb_value upb_strtable_iter_value(const upb_strtable_iter *i);
+void upb_strtable_iter_setdone(upb_strtable_iter *i);
+bool upb_strtable_iter_isequal(const upb_strtable_iter *i1,
+                               const upb_strtable_iter *i2);
+
+
+/* upb_inttable_iter **********************************************************/
+
+//   upb_inttable_iter i;
+//   upb_inttable_begin(&i, t);
+//   for(; !upb_inttable_done(&i); upb_inttable_next(&i)) {
+//     uintptr_t key = upb_inttable_iter_key(&i);
+//     upb_value val = upb_inttable_iter_value(&i);
+//     // ...
+//   }
+
+typedef struct {
+  const upb_inttable *t;
+  size_t index;
+  bool array_part;
+} upb_inttable_iter;
+
+void upb_inttable_begin(upb_inttable_iter *i, const upb_inttable *t);
+void upb_inttable_next(upb_inttable_iter *i);
+bool upb_inttable_done(const upb_inttable_iter *i);
+uintptr_t upb_inttable_iter_key(const upb_inttable_iter *i);
+upb_value upb_inttable_iter_value(const upb_inttable_iter *i);
+void upb_inttable_iter_setdone(upb_inttable_iter *i);
+bool upb_inttable_iter_isequal(const upb_inttable_iter *i1,
+                               const upb_inttable_iter *i2);
+
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif  /* UPB_TABLE_H_ */
+
+// Reference tracking will check ref()/unref() operations to make sure the
+// ref ownership is correct.  Where possible it will also make tools like
+// Valgrind attribute ref leaks to the code that took the leaked ref, not
+// the code that originally created the object.
+//
+// Enabling this requires the application to define upb_lock()/upb_unlock()
+// functions that acquire/release a global mutex (or #define UPB_THREAD_UNSAFE).
+#ifndef NDEBUG
+#define UPB_DEBUG_REFS
+#endif
+
+#ifdef __cplusplus
+namespace upb { class RefCounted; }
+#endif
+
+UPB_DECLARE_TYPE(upb::RefCounted, upb_refcounted);
+
+struct upb_refcounted_vtbl;
+
+UPB_DEFINE_CLASS0(upb::RefCounted,
+ public:
+  // Returns true if the given object is frozen.
+  bool IsFrozen() const;
+
+  // Increases the ref count, the new ref is owned by "owner" which must not
+  // already own a ref (and should not itself be a refcounted object if the ref
+  // could possibly be circular; see below).
+  // Thread-safe iff "this" is frozen.
+  void Ref(const void *owner) const;
+
+  // Release a ref that was acquired from upb_refcounted_ref() and collects any
+  // objects it can.
+  void Unref(const void *owner) const;
+
+  // Moves an existing ref from "from" to "to", without changing the overall
+  // ref count.  DonateRef(foo, NULL, owner) is the same as Ref(foo, owner),
+  // but "to" may not be NULL.
+  void DonateRef(const void *from, const void *to) const;
+
+  // Verifies that a ref to the given object is currently held by the given
+  // owner.  Only effective in UPB_DEBUG_REFS builds.
+  void CheckRef(const void *owner) const;
+
+ private:
+  UPB_DISALLOW_POD_OPS(RefCounted, upb::RefCounted);
+,
+UPB_DEFINE_STRUCT0(upb_refcounted,
+  // A single reference count shared by all objects in the group.
+  uint32_t *group;
+
+  // A singly-linked list of all objects in the group.
+  upb_refcounted *next;
+
+  // Table of function pointers for this type.
+  const struct upb_refcounted_vtbl *vtbl;
+
+  // Maintained only when mutable, this tracks the number of refs (but not
+  // ref2's) to this object.  *group should be the sum of all individual_count
+  // in the group.
+  uint32_t individual_count;
+
+  bool is_frozen;
+
+#ifdef UPB_DEBUG_REFS
+  upb_inttable *refs;  // Maps owner -> trackedref for incoming refs.
+  upb_inttable *ref2s; // Set of targets for outgoing ref2s.
+#endif
+));
+
+UPB_BEGIN_EXTERN_C  // {
+
+// It is better to use tracked refs when possible, for the extra debugging
+// capability.  But if this is not possible (because you don't have easy access
+// to a stable pointer value that is associated with the ref), you can pass
+// UPB_UNTRACKED_REF instead.
+extern const void *UPB_UNTRACKED_REF;
+
+// Native C API.
+bool upb_refcounted_isfrozen(const upb_refcounted *r);
+void upb_refcounted_ref(const upb_refcounted *r, const void *owner);
+void upb_refcounted_unref(const upb_refcounted *r, const void *owner);
+void upb_refcounted_donateref(
+    const upb_refcounted *r, const void *from, const void *to);
+void upb_refcounted_checkref(const upb_refcounted *r, const void *owner);
+
+
+// Internal-to-upb Interface ///////////////////////////////////////////////////
+
+typedef void upb_refcounted_visit(const upb_refcounted *r,
+                                  const upb_refcounted *subobj,
+                                  void *closure);
+
+struct upb_refcounted_vtbl {
+  // Must visit all subobjects that are currently ref'd via upb_refcounted_ref2.
+  // Must be longjmp()-safe.
+  void (*visit)(const upb_refcounted *r, upb_refcounted_visit *visit, void *c);
+
+  // Must free the object and release all references to other objects.
+  void (*free)(upb_refcounted *r);
+};
+
+// Initializes the refcounted with a single ref for the given owner.  Returns
+// false if memory could not be allocated.
+bool upb_refcounted_init(upb_refcounted *r,
+                         const struct upb_refcounted_vtbl *vtbl,
+                         const void *owner);
+
+// Adds a ref from one refcounted object to another ("from" must not already
+// own a ref).  These refs may be circular; cycles will be collected correctly
+// (if conservatively).  These refs do not need to be freed in from's free()
+// function.
+void upb_refcounted_ref2(const upb_refcounted *r, upb_refcounted *from);
+
+// Removes a ref that was acquired from upb_refcounted_ref2(), and collects any
+// object it can.  This is only necessary when "from" no longer points to "r",
+// and not from from's "free" function.
+void upb_refcounted_unref2(const upb_refcounted *r, upb_refcounted *from);
+
+#define upb_ref2(r, from) \
+    upb_refcounted_ref2((const upb_refcounted*)r, (upb_refcounted*)from)
+#define upb_unref2(r, from) \
+    upb_refcounted_unref2((const upb_refcounted*)r, (upb_refcounted*)from)
+
+// Freezes all mutable object reachable by ref2() refs from the given roots.
+// This will split refcounting groups into precise SCC groups, so that
+// refcounting of frozen objects can be more aggressive.  If memory allocation
+// fails, or if more than 2**31 mutable objects are reachable from "roots", or
+// if the maximum depth of the graph exceeds "maxdepth", false is returned and
+// the objects are unchanged.
+//
+// After this operation succeeds, the objects are frozen/const, and may not be
+// used through non-const pointers.  In particular, they may not be passed as
+// the second parameter of upb_refcounted_{ref,unref}2().  On the upside, all
+// operations on frozen refcounteds are threadsafe, and objects will be freed
+// at the precise moment that they become unreachable.
+//
+// Caller must own refs on each object in the "roots" list.
+bool upb_refcounted_freeze(upb_refcounted *const*roots, int n, upb_status *s,
+                           int maxdepth);
+
+// Shared by all compiled-in refcounted objects.
+extern uint32_t static_refcount;
+
+UPB_END_EXTERN_C  // }
+
+#ifdef UPB_DEBUG_REFS
+#define UPB_REFCOUNT_INIT(refs, ref2s) \
+    {&static_refcount, NULL, NULL, 0, true, refs, ref2s}
+#else
+#define UPB_REFCOUNT_INIT(refs, ref2s) {&static_refcount, NULL, NULL, 0, true}
+#endif
+
+#ifdef __cplusplus
+// C++ Wrappers.
+namespace upb {
+inline bool RefCounted::IsFrozen() const {
+  return upb_refcounted_isfrozen(this);
+}
+inline void RefCounted::Ref(const void *owner) const {
+  upb_refcounted_ref(this, owner);
+}
+inline void RefCounted::Unref(const void *owner) const {
+  upb_refcounted_unref(this, owner);
+}
+inline void RefCounted::DonateRef(const void *from, const void *to) const {
+  upb_refcounted_donateref(this, from, to);
+}
+inline void RefCounted::CheckRef(const void *owner) const {
+  upb_refcounted_checkref(this, owner);
+}
+}  // namespace upb
+#endif
+
+#endif  // UPB_REFCOUNT_H_
+
+#ifdef __cplusplus
+#include <cstring>
+#include <string>
+#include <vector>
+
+namespace upb {
+class Def;
+class EnumDef;
+class FieldDef;
+class MessageDef;
+}
+#endif
+
+UPB_DECLARE_TYPE(upb::Def, upb_def);
+UPB_DECLARE_TYPE(upb::EnumDef, upb_enumdef);
+UPB_DECLARE_TYPE(upb::FieldDef, upb_fielddef);
+UPB_DECLARE_TYPE(upb::MessageDef, upb_msgdef);
+
+// Maximum field number allowed for FieldDefs.  This is an inherent limit of the
+// protobuf wire format.
+#define UPB_MAX_FIELDNUMBER ((1 << 29) - 1)
+
+// The maximum message depth that the type graph can have.  This is a resource
+// limit for the C stack since we sometimes need to recursively traverse the
+// graph.  Cycles are ok; the traversal will stop when it detects a cycle, but
+// we must hit the cycle before the maximum depth is reached.
+//
+// If having a single static limit is too inflexible, we can add another variant
+// of Def::Freeze that allows specifying this as a parameter.
+#define UPB_MAX_MESSAGE_DEPTH 64
+
+
+/* upb::Def: base class for defs  *********************************************/
+
+// All the different kind of defs we support.  These correspond 1:1 with
+// declarations in a .proto file.
+typedef enum {
+  UPB_DEF_MSG,
+  UPB_DEF_FIELD,
+  UPB_DEF_ENUM,
+  UPB_DEF_SERVICE,   // Not yet implemented.
+  UPB_DEF_ANY = -1,  // Wildcard for upb_symtab_get*()
+} upb_deftype_t;
+
+// The base class of all defs.  Its base is upb::RefCounted (use upb::upcast()
+// to convert).
+UPB_DEFINE_CLASS1(upb::Def, upb::RefCounted,
+ public:
+  typedef upb_deftype_t Type;
+
+  Def* Dup(const void *owner) const;
+
+  // Functionality from upb::RefCounted.
+  bool IsFrozen() const;
+  void Ref(const void* owner) const;
+  void Unref(const void* owner) const;
+  void DonateRef(const void* from, const void* to) const;
+  void CheckRef(const void* owner) const;
+
+  Type def_type() const;
+
+  // "fullname" is the def's fully-qualified name (eg. foo.bar.Message).
+  const char *full_name() const;
+
+  // The def must be mutable.  Caller retains ownership of fullname.  Defs are
+  // not required to have a name; if a def has no name when it is frozen, it
+  // will remain an anonymous def.  On failure, returns false and details in "s"
+  // if non-NULL.
+  bool set_full_name(const char* fullname, upb::Status* s);
+  bool set_full_name(const std::string &fullname, upb::Status* s);
+
+  // Freezes the given defs; this validates all constraints and marks the defs
+  // as frozen (read-only).  "defs" may not contain any fielddefs, but fields
+  // of any msgdefs will be frozen.
+  //
+  // Symbolic references to sub-types and enum defaults must have already been
+  // resolved.  Any mutable defs reachable from any of "defs" must also be in
+  // the list; more formally, "defs" must be a transitive closure of mutable
+  // defs.
+  //
+  // After this operation succeeds, the finalized defs must only be accessed
+  // through a const pointer!
+  static bool Freeze(Def* const* defs, int n, Status* status);
+  static bool Freeze(const std::vector<Def*>& defs, Status* status);
+
+ private:
+  UPB_DISALLOW_POD_OPS(Def, upb::Def);
+,
+UPB_DEFINE_STRUCT(upb_def, upb_refcounted,
+  const char *fullname;
+  upb_deftype_t type : 8;
+  // Used as a flag during the def's mutable stage.  Must be false unless
+  // it is currently being used by a function on the stack.  This allows
+  // us to easily determine which defs were passed into the function's
+  // current invocation.
+  bool came_from_user;
+));
+
+#define UPB_DEF_INIT(name, type, refs, ref2s) \
+    { UPB_REFCOUNT_INIT(refs, ref2s), name, type, false }
+
+UPB_BEGIN_EXTERN_C  // {
+
+// Native C API.
+upb_def *upb_def_dup(const upb_def *def, const void *owner);
+
+// From upb_refcounted.
+bool upb_def_isfrozen(const upb_def *def);
+void upb_def_ref(const upb_def *def, const void *owner);
+void upb_def_unref(const upb_def *def, const void *owner);
+void upb_def_donateref(const upb_def *def, const void *from, const void *to);
+void upb_def_checkref(const upb_def *def, const void *owner);
+
+upb_deftype_t upb_def_type(const upb_def *d);
+const char *upb_def_fullname(const upb_def *d);
+bool upb_def_setfullname(upb_def *def, const char *fullname, upb_status *s);
+bool upb_def_freeze(upb_def *const *defs, int n, upb_status *s);
+
+UPB_END_EXTERN_C  // }
+
+
+/* upb::Def casts *************************************************************/
+
+#ifdef __cplusplus
+#define UPB_CPP_CASTS(cname, cpptype)                                          \
+  namespace upb {                                                              \
+  template <>                                                                  \
+  inline cpptype *down_cast<cpptype *, Def>(Def * def) {                       \
+    return upb_downcast_##cname##_mutable(def);                                \
+  }                                                                            \
+  template <>                                                                  \
+  inline cpptype *dyn_cast<cpptype *, Def>(Def * def) {                        \
+    return upb_dyncast_##cname##_mutable(def);                                 \
+  }                                                                            \
+  template <>                                                                  \
+  inline const cpptype *down_cast<const cpptype *, const Def>(                 \
+      const Def *def) {                                                        \
+    return upb_downcast_##cname(def);                                          \
+  }                                                                            \
+  template <>                                                                  \
+  inline const cpptype *dyn_cast<const cpptype *, const Def>(const Def *def) { \
+    return upb_dyncast_##cname(def);                                           \
+  }                                                                            \
+  template <>                                                                  \
+  inline const cpptype *down_cast<const cpptype *, Def>(Def * def) {           \
+    return upb_downcast_##cname(def);                                          \
+  }                                                                            \
+  template <>                                                                  \
+  inline const cpptype *dyn_cast<const cpptype *, Def>(Def * def) {            \
+    return upb_dyncast_##cname(def);                                           \
+  }                                                                            \
+  }  // namespace upb
+#else
+#define UPB_CPP_CASTS(cname, cpptype)
+#endif
+
+// Dynamic casts, for determining if a def is of a particular type at runtime.
+// Downcasts, for when some wants to assert that a def is of a particular type.
+// These are only checked if we are building debug.
+#define UPB_DEF_CASTS(lower, upper, cpptype)                               \
+  UPB_INLINE const upb_##lower *upb_dyncast_##lower(const upb_def *def) {  \
+    if (upb_def_type(def) != UPB_DEF_##upper) return NULL;                 \
+    return (upb_##lower *)def;                                             \
+  }                                                                        \
+  UPB_INLINE const upb_##lower *upb_downcast_##lower(const upb_def *def) { \
+    assert(upb_def_type(def) == UPB_DEF_##upper);                          \
+    return (const upb_##lower *)def;                                       \
+  }                                                                        \
+  UPB_INLINE upb_##lower *upb_dyncast_##lower##_mutable(upb_def *def) {    \
+    return (upb_##lower *)upb_dyncast_##lower(def);                        \
+  }                                                                        \
+  UPB_INLINE upb_##lower *upb_downcast_##lower##_mutable(upb_def *def) {   \
+    return (upb_##lower *)upb_downcast_##lower(def);                       \
+  }                                                                        \
+  UPB_CPP_CASTS(lower, cpptype)
+
+#define UPB_DEFINE_DEF(cppname, lower, upper, cppmethods, members)             \
+  UPB_DEFINE_CLASS2(cppname, upb::Def, upb::RefCounted, UPB_QUOTE(cppmethods), \
+                   members)                                                    \
+  UPB_DEF_CASTS(lower, upper, cppname)
+
+
+/* upb::FieldDef **************************************************************/
+
+// The types a field can have.  Note that this list is not identical to the
+// types defined in descriptor.proto, which gives INT32 and SINT32 separate
+// types (we distinguish the two with the "integer encoding" enum below).
+typedef enum {
+  UPB_TYPE_FLOAT    = 1,
+  UPB_TYPE_DOUBLE   = 2,
+  UPB_TYPE_BOOL     = 3,
+  UPB_TYPE_STRING   = 4,
+  UPB_TYPE_BYTES    = 5,
+  UPB_TYPE_MESSAGE  = 6,
+  UPB_TYPE_ENUM     = 7,  // Enum values are int32.
+  UPB_TYPE_INT32    = 8,
+  UPB_TYPE_UINT32   = 9,
+  UPB_TYPE_INT64    = 10,
+  UPB_TYPE_UINT64   = 11,
+} upb_fieldtype_t;
+
+// The repeated-ness of each field; this matches descriptor.proto.
+typedef enum {
+  UPB_LABEL_OPTIONAL = 1,
+  UPB_LABEL_REQUIRED = 2,
+  UPB_LABEL_REPEATED = 3,
+} upb_label_t;
+
+// How integers should be encoded in serializations that offer multiple
+// integer encoding methods.
+typedef enum {
+  UPB_INTFMT_VARIABLE = 1,
+  UPB_INTFMT_FIXED = 2,
+  UPB_INTFMT_ZIGZAG = 3,  // Only for signed types (INT32/INT64).
+} upb_intfmt_t;
+
+// Descriptor types, as defined in descriptor.proto.
+typedef enum {
+  UPB_DESCRIPTOR_TYPE_DOUBLE   = 1,
+  UPB_DESCRIPTOR_TYPE_FLOAT    = 2,
+  UPB_DESCRIPTOR_TYPE_INT64    = 3,
+  UPB_DESCRIPTOR_TYPE_UINT64   = 4,
+  UPB_DESCRIPTOR_TYPE_INT32    = 5,
+  UPB_DESCRIPTOR_TYPE_FIXED64  = 6,
+  UPB_DESCRIPTOR_TYPE_FIXED32  = 7,
+  UPB_DESCRIPTOR_TYPE_BOOL     = 8,
+  UPB_DESCRIPTOR_TYPE_STRING   = 9,
+  UPB_DESCRIPTOR_TYPE_GROUP    = 10,
+  UPB_DESCRIPTOR_TYPE_MESSAGE  = 11,
+  UPB_DESCRIPTOR_TYPE_BYTES    = 12,
+  UPB_DESCRIPTOR_TYPE_UINT32   = 13,
+  UPB_DESCRIPTOR_TYPE_ENUM     = 14,
+  UPB_DESCRIPTOR_TYPE_SFIXED32 = 15,
+  UPB_DESCRIPTOR_TYPE_SFIXED64 = 16,
+  UPB_DESCRIPTOR_TYPE_SINT32   = 17,
+  UPB_DESCRIPTOR_TYPE_SINT64   = 18,
+} upb_descriptortype_t;
+
+
+// A upb_fielddef describes a single field in a message.  It is most often
+// found as a part of a upb_msgdef, but can also stand alone to represent
+// an extension.
+//
+// Its base class is upb::Def (use upb::upcast() to convert).
+UPB_DEFINE_DEF(upb::FieldDef, fielddef, FIELD,
+ public:
+  typedef upb_fieldtype_t Type;
+  typedef upb_label_t Label;
+  typedef upb_intfmt_t IntegerFormat;
+  typedef upb_descriptortype_t DescriptorType;
+
+  // These return true if the given value is a valid member of the enumeration.
+  static bool CheckType(int32_t val);
+  static bool CheckLabel(int32_t val);
+  static bool CheckDescriptorType(int32_t val);
+  static bool CheckIntegerFormat(int32_t val);
+
+  // These convert to the given enumeration; they require that the value is
+  // valid.
+  static Type ConvertType(int32_t val);
+  static Label ConvertLabel(int32_t val);
+  static DescriptorType ConvertDescriptorType(int32_t val);
+  static IntegerFormat ConvertIntegerFormat(int32_t val);
+
+  // Returns NULL if memory allocation failed.
+  static reffed_ptr<FieldDef> New();
+
+  // Duplicates the given field, returning NULL if memory allocation failed.
+  // When a fielddef is duplicated, the subdef (if any) is made symbolic if it
+  // wasn't already.  If the subdef is set but has no name (which is possible
+  // since msgdefs are not required to have a name) the new fielddef's subdef
+  // will be unset.
+  FieldDef* Dup(const void* owner) const;
+
+  // Functionality from upb::RefCounted.
+  bool IsFrozen() const;
+  void Ref(const void* owner) const;
+  void Unref(const void* owner) const;
+  void DonateRef(const void* from, const void* to) const;
+  void CheckRef(const void* owner) const;
+
+  // Functionality from upb::Def.
+  const char* full_name() const;
+
+  bool type_is_set() const;  // Whether set_[descriptor_]type() has been called.
+  Type type() const;         // Requires that type_is_set() == true.
+  Label label() const;       // Defaults to UPB_LABEL_OPTIONAL.
+  const char* name() const;  // NULL if uninitialized.
+  uint32_t number() const;   // Returns 0 if uninitialized.
+  bool is_extension() const;
+
+  // For UPB_TYPE_MESSAGE fields only where is_tag_delimited() == false,
+  // indicates whether this field should have lazy parsing handlers that yield
+  // the unparsed string for the submessage.
+  //
+  // TODO(haberman): I think we want to move this into a FieldOptions container
+  // when we add support for custom options (the FieldOptions struct will
+  // contain both regular FieldOptions like "lazy" *and* custom options).
+  bool lazy() const;
+
+  // For non-string, non-submessage fields, this indicates whether binary
+  // protobufs are encoded in packed or non-packed format.
+  //
+  // TODO(haberman): see note above about putting options like this into a
+  // FieldOptions container.
+  bool packed() const;
+
+  // An integer that can be used as an index into an array of fields for
+  // whatever message this field belongs to.  Guaranteed to be less than
+  // f->containing_type()->field_count().  May only be accessed once the def has
+  // been finalized.
+  int index() const;
+
+  // The MessageDef to which this field belongs.
+  //
+  // If this field has been added to a MessageDef, that message can be retrieved
+  // directly (this is always the case for frozen FieldDefs).
+  //
+  // If the field has not yet been added to a MessageDef, you can set the name
+  // of the containing type symbolically instead.  This is mostly useful for
+  // extensions, where the extension is declared separately from the message.
+  const MessageDef* containing_type() const;
+  const char* containing_type_name();
+
+  // The field's type according to the enum in descriptor.proto.  This is not
+  // the same as UPB_TYPE_*, because it distinguishes between (for example)
+  // INT32 and SINT32, whereas our "type" enum does not.  This return of
+  // descriptor_type() is a function of type(), integer_format(), and
+  // is_tag_delimited().  Likewise set_descriptor_type() sets all three
+  // appropriately.
+  DescriptorType descriptor_type() const;
+
+  // Convenient field type tests.
+  bool IsSubMessage() const;
+  bool IsString() const;
+  bool IsSequence() const;
+  bool IsPrimitive() const;
+
+  // How integers are encoded.  Only meaningful for integer types.
+  // Defaults to UPB_INTFMT_VARIABLE, and is reset when "type" changes.
+  IntegerFormat integer_format() const;
+
+  // Whether a submessage field is tag-delimited or not (if false, then
+  // length-delimited).  May only be set when type() == UPB_TYPE_MESSAGE.
+  bool is_tag_delimited() const;
+
+  // Returns the non-string default value for this fielddef, which may either
+  // be something the client set explicitly or the "default default" (0 for
+  // numbers, empty for strings).  The field's type indicates the type of the
+  // returned value, except for enum fields that are still mutable.
+  //
+  // Requires that the given function matches the field's current type.
+  int64_t default_int64() const;
+  int32_t default_int32() const;
+  uint64_t default_uint64() const;
+  uint32_t default_uint32() const;
+  bool default_bool() const;
+  float default_float() const;
+  double default_double() const;
+
+  // The resulting string is always NULL-terminated.  If non-NULL, the length
+  // will be stored in *len.
+  const char *default_string(size_t* len) const;
+
+  // For frozen UPB_TYPE_ENUM fields, enum defaults can always be read as either
+  // string or int32, and both of these methods will always return true.
+  //
+  // For mutable UPB_TYPE_ENUM fields, the story is a bit more complicated.
+  // Enum defaults are unusual. They can be specified either as string or int32,
+  // but to be valid the enum must have that value as a member.  And if no
+  // default is specified, the "default default" comes from the EnumDef.
+  //
+  // We allow reading the default as either an int32 or a string, but only if
+  // we have a meaningful value to report.  We have a meaningful value if it was
+  // set explicitly, or if we could get the "default default" from the EnumDef.
+  // Also if you explicitly set the name and we find the number in the EnumDef
+  bool EnumHasStringDefault() const;
+  bool EnumHasInt32Default() const;
+
+  // Submessage and enum fields must reference a "subdef", which is the
+  // upb::MessageDef or upb::EnumDef that defines their type.  Note that when
+  // the FieldDef is mutable it may not have a subdef *yet*, but this function
+  // still returns true to indicate that the field's type requires a subdef.
+  bool HasSubDef() const;
+
+  // Returns the enum or submessage def for this field, if any.  The field's
+  // type must match (ie. you may only call enum_subdef() for fields where
+  // type() == UPB_TYPE_ENUM).  Returns NULL if the subdef has not been set or
+  // is currently set symbolically.
+  const EnumDef* enum_subdef() const;
+  const MessageDef* message_subdef() const;
+
+  // Returns the generic subdef for this field.  Requires that HasSubDef() (ie.
+  // only works for UPB_TYPE_ENUM and UPB_TYPE_MESSAGE fields).
+  const Def* subdef() const;
+
+  // Returns the symbolic name of the subdef.  If the subdef is currently set
+  // unresolved (ie. set symbolically) returns the symbolic name.  If it has
+  // been resolved to a specific subdef, returns the name from that subdef.
+  const char* subdef_name() const;
+
+  //////////////////////////////////////////////////////////////////////////////
+  // Setters (non-const methods), only valid for mutable FieldDefs!
+  //////////////////////////////////////////////////////////////////////////////
+
+  bool set_full_name(const char* fullname, upb::Status* s);
+  bool set_full_name(const std::string& fullname, upb::Status* s);
+
+  // This may only be called if containing_type() == NULL (ie. the field has not
+  // been added to a message yet).
+  bool set_containing_type_name(const char *name, Status* status);
+  bool set_containing_type_name(const std::string& name, Status* status);
+
+  // Defaults to false.  When we freeze, we ensure that this can only be true
+  // for length-delimited message fields.  Prior to freezing this can be true or
+  // false with no restrictions.
+  void set_lazy(bool lazy);
+
+  // Defaults to true.  Sets whether this field is encoded in packed format.
+  void set_packed(bool packed);
+
+  // "type" or "descriptor_type" MUST be set explicitly before the fielddef is
+  // finalized.  These setters require that the enum value is valid; if the
+  // value did not come directly from an enum constant, the caller should
+  // validate it first with the functions above (CheckFieldType(), etc).
+  void set_type(Type type);
+  void set_label(Label label);
+  void set_descriptor_type(DescriptorType type);
+  void set_is_extension(bool is_extension);
+
+  // "number" and "name" must be set before the FieldDef is added to a
+  // MessageDef, and may not be set after that.
+  //
+  // "name" is the same as full_name()/set_full_name(), but since fielddefs
+  // most often use simple, non-qualified names, we provide this accessor
+  // also.  Generally only extensions will want to think of this name as
+  // fully-qualified.
+  bool set_number(uint32_t number, upb::Status* s);
+  bool set_name(const char* name, upb::Status* s);
+  bool set_name(const std::string& name, upb::Status* s);
+
+  void set_integer_format(IntegerFormat format);
+  bool set_tag_delimited(bool tag_delimited, upb::Status* s);
+
+  // Sets default value for the field.  The call must exactly match the type
+  // of the field.  Enum fields may use either setint32 or setstring to set
+  // the default numerically or symbolically, respectively, but symbolic
+  // defaults must be resolved before finalizing (see ResolveEnumDefault()).
+  //
+  // Changing the type of a field will reset its default.
+  void set_default_int64(int64_t val);
+  void set_default_int32(int32_t val);
+  void set_default_uint64(uint64_t val);
+  void set_default_uint32(uint32_t val);
+  void set_default_bool(bool val);
+  void set_default_float(float val);
+  void set_default_double(double val);
+  bool set_default_string(const void *str, size_t len, Status *s);
+  bool set_default_string(const std::string &str, Status *s);
+  void set_default_cstr(const char *str, Status *s);
+
+  // Before a fielddef is frozen, its subdef may be set either directly (with a
+  // upb::Def*) or symbolically.  Symbolic refs must be resolved before the
+  // containing msgdef can be frozen (see upb_resolve() above).  upb always
+  // guarantees that any def reachable from a live def will also be kept alive.
+  //
+  // Both methods require that upb_hassubdef(f) (so the type must be set prior
+  // to calling these methods).  Returns false if this is not the case, or if
+  // the given subdef is not of the correct type.  The subdef is reset if the
+  // field's type is changed.  The subdef can be set to NULL to clear it.
+  bool set_subdef(const Def* subdef, Status* s);
+  bool set_enum_subdef(const EnumDef* subdef, Status* s);
+  bool set_message_subdef(const MessageDef* subdef, Status* s);
+  bool set_subdef_name(const char* name, Status* s);
+  bool set_subdef_name(const std::string &name, Status* s);
+
+ private:
+  UPB_DISALLOW_POD_OPS(FieldDef, upb::FieldDef);
+,
+UPB_DEFINE_STRUCT(upb_fielddef, upb_def,
+  union {
+    int64_t sint;
+    uint64_t uint;
+    double dbl;
+    float flt;
+    void *bytes;
+  } defaultval;
+  union {
+    const upb_msgdef *def;  // If !msg_is_symbolic.
+    char *name;             // If msg_is_symbolic.
+  } msg;
+  union {
+    const upb_def *def;  // If !subdef_is_symbolic.
+    char *name;          // If subdef_is_symbolic.
+  } sub;  // The msgdef or enumdef for this field, if upb_hassubdef(f).
+  bool subdef_is_symbolic;
+  bool msg_is_symbolic;
+  bool default_is_string;
+  bool type_is_set_;     // False until type is explicitly set.
+  bool is_extension_;
+  bool lazy_;
+  bool packed_;
+  upb_intfmt_t intfmt;
+  bool tagdelim;
+  upb_fieldtype_t type_;
+  upb_label_t label_;
+  uint32_t number_;
+  uint32_t selector_base;  // Used to index into a upb::Handlers table.
+  uint32_t index_;
+));
+
+#define UPB_FIELDDEF_INIT(label, type, intfmt, tagdelim, is_extension, lazy,   \
+                          packed, name, num, msgdef, subdef, selector_base,     \
+                          index, defaultval, refs, ref2s)                      \
+  {                                                                            \
+    UPB_DEF_INIT(name, UPB_DEF_FIELD, refs, ref2s), defaultval, {msgdef},      \
+        {subdef}, false, false,                                                \
+        type == UPB_TYPE_STRING || type == UPB_TYPE_BYTES, true, is_extension, \
+        lazy, packed, intfmt, tagdelim, type, label, num, selector_base, index \
+  }
+
+UPB_BEGIN_EXTERN_C  // {
+
+// Native C API.
+upb_fielddef *upb_fielddef_new(const void *owner);
+upb_fielddef *upb_fielddef_dup(const upb_fielddef *f, const void *owner);
+
+// From upb_refcounted.
+bool upb_fielddef_isfrozen(const upb_fielddef *f);
+void upb_fielddef_ref(const upb_fielddef *f, const void *owner);
+void upb_fielddef_unref(const upb_fielddef *f, const void *owner);
+void upb_fielddef_donateref(const upb_fielddef *f, const void *from,
+                            const void *to);
+void upb_fielddef_checkref(const upb_fielddef *f, const void *owner);
+
+// From upb_def.
+const char *upb_fielddef_fullname(const upb_fielddef *f);
+bool upb_fielddef_setfullname(upb_fielddef *f, const char *fullname,
+                              upb_status *s);
+
+bool upb_fielddef_typeisset(const upb_fielddef *f);
+upb_fieldtype_t upb_fielddef_type(const upb_fielddef *f);
+upb_descriptortype_t upb_fielddef_descriptortype(const upb_fielddef *f);
+upb_label_t upb_fielddef_label(const upb_fielddef *f);
+uint32_t upb_fielddef_number(const upb_fielddef *f);
+const char *upb_fielddef_name(const upb_fielddef *f);
+bool upb_fielddef_isextension(const upb_fielddef *f);
+bool upb_fielddef_lazy(const upb_fielddef *f);
+bool upb_fielddef_packed(const upb_fielddef *f);
+const upb_msgdef *upb_fielddef_containingtype(const upb_fielddef *f);
+upb_msgdef *upb_fielddef_containingtype_mutable(upb_fielddef *f);
+const char *upb_fielddef_containingtypename(upb_fielddef *f);
+upb_intfmt_t upb_fielddef_intfmt(const upb_fielddef *f);
+uint32_t upb_fielddef_index(const upb_fielddef *f);
+bool upb_fielddef_istagdelim(const upb_fielddef *f);
+bool upb_fielddef_issubmsg(const upb_fielddef *f);
+bool upb_fielddef_isstring(const upb_fielddef *f);
+bool upb_fielddef_isseq(const upb_fielddef *f);
+bool upb_fielddef_isprimitive(const upb_fielddef *f);
+int64_t upb_fielddef_defaultint64(const upb_fielddef *f);
+int32_t upb_fielddef_defaultint32(const upb_fielddef *f);
+uint64_t upb_fielddef_defaultuint64(const upb_fielddef *f);
+uint32_t upb_fielddef_defaultuint32(const upb_fielddef *f);
+bool upb_fielddef_defaultbool(const upb_fielddef *f);
+float upb_fielddef_defaultfloat(const upb_fielddef *f);
+double upb_fielddef_defaultdouble(const upb_fielddef *f);
+const char *upb_fielddef_defaultstr(const upb_fielddef *f, size_t *len);
+bool upb_fielddef_enumhasdefaultint32(const upb_fielddef *f);
+bool upb_fielddef_enumhasdefaultstr(const upb_fielddef *f);
+bool upb_fielddef_hassubdef(const upb_fielddef *f);
+const upb_def *upb_fielddef_subdef(const upb_fielddef *f);
+const upb_msgdef *upb_fielddef_msgsubdef(const upb_fielddef *f);
+const upb_enumdef *upb_fielddef_enumsubdef(const upb_fielddef *f);
+const char *upb_fielddef_subdefname(const upb_fielddef *f);
+
+void upb_fielddef_settype(upb_fielddef *f, upb_fieldtype_t type);
+void upb_fielddef_setdescriptortype(upb_fielddef *f, int type);
+void upb_fielddef_setlabel(upb_fielddef *f, upb_label_t label);
+bool upb_fielddef_setnumber(upb_fielddef *f, uint32_t number, upb_status *s);
+bool upb_fielddef_setname(upb_fielddef *f, const char *name, upb_status *s);
+bool upb_fielddef_setcontainingtypename(upb_fielddef *f, const char *name,
+                                        upb_status *s);
+void upb_fielddef_setisextension(upb_fielddef *f, bool is_extension);
+void upb_fielddef_setlazy(upb_fielddef *f, bool lazy);
+void upb_fielddef_setpacked(upb_fielddef *f, bool packed);
+void upb_fielddef_setintfmt(upb_fielddef *f, upb_intfmt_t fmt);
+void upb_fielddef_settagdelim(upb_fielddef *f, bool tag_delim);
+void upb_fielddef_setdefaultint64(upb_fielddef *f, int64_t val);
+void upb_fielddef_setdefaultint32(upb_fielddef *f, int32_t val);
+void upb_fielddef_setdefaultuint64(upb_fielddef *f, uint64_t val);
+void upb_fielddef_setdefaultuint32(upb_fielddef *f, uint32_t val);
+void upb_fielddef_setdefaultbool(upb_fielddef *f, bool val);
+void upb_fielddef_setdefaultfloat(upb_fielddef *f, float val);
+void upb_fielddef_setdefaultdouble(upb_fielddef *f, double val);
+bool upb_fielddef_setdefaultstr(upb_fielddef *f, const void *str, size_t len,
+                                upb_status *s);
+void upb_fielddef_setdefaultcstr(upb_fielddef *f, const char *str,
+                                 upb_status *s);
+bool upb_fielddef_setsubdef(upb_fielddef *f, const upb_def *subdef,
+                            upb_status *s);
+bool upb_fielddef_setmsgsubdef(upb_fielddef *f, const upb_msgdef *subdef,
+                               upb_status *s);
+bool upb_fielddef_setenumsubdef(upb_fielddef *f, const upb_enumdef *subdef,
+                                upb_status *s);
+bool upb_fielddef_setsubdefname(upb_fielddef *f, const char *name,
+                                upb_status *s);
+
+bool upb_fielddef_checklabel(int32_t label);
+bool upb_fielddef_checktype(int32_t type);
+bool upb_fielddef_checkdescriptortype(int32_t type);
+bool upb_fielddef_checkintfmt(int32_t fmt);
+
+UPB_END_EXTERN_C  // }
+
+
+/* upb::MessageDef ************************************************************/
+
+typedef upb_inttable_iter upb_msg_iter;
+
+// Structure that describes a single .proto message type.
+//
+// Its base class is upb::Def (use upb::upcast() to convert).
+UPB_DEFINE_DEF(upb::MessageDef, msgdef, MSG, UPB_QUOTE(
+ public:
+  // Returns NULL if memory allocation failed.
+  static reffed_ptr<MessageDef> New();
+
+  // Functionality from upb::RefCounted.
+  bool IsFrozen() const;
+  void Ref(const void* owner) const;
+  void Unref(const void* owner) const;
+  void DonateRef(const void* from, const void* to) const;
+  void CheckRef(const void* owner) const;
+
+  // Functionality from upb::Def.
+  const char* full_name() const;
+  bool set_full_name(const char* fullname, Status* s);
+  bool set_full_name(const std::string& fullname, Status* s);
+
+  // Call to freeze this MessageDef.
+  // WARNING: this will fail if this message has any unfrozen submessages!
+  // Messages with cycles must be frozen as a batch using upb::Def::Freeze().
+  bool Freeze(Status* s);
+
+  // The number of fields that belong to the MessageDef.
+  int field_count() const;
+
+  // Adds a field (upb_fielddef object) to a msgdef.  Requires that the msgdef
+  // and the fielddefs are mutable.  The fielddef's name and number must be
+  // set, and the message may not already contain any field with this name or
+  // number, and this fielddef may not be part of another message.  In error
+  // cases false is returned and the msgdef is unchanged.
+  bool AddField(FieldDef* f, Status* s);
+  bool AddField(const reffed_ptr<FieldDef>& f, Status* s);
+
+  // These return NULL if the field is not found.
+  FieldDef* FindFieldByNumber(uint32_t number);
+  FieldDef* FindFieldByName(const char *name, size_t len);
+  const FieldDef* FindFieldByNumber(uint32_t number) const;
+  const FieldDef* FindFieldByName(const char* name, size_t len) const;
+
+
+  FieldDef* FindFieldByName(const char *name) {
+    return FindFieldByName(name, strlen(name));
+  }
+  const FieldDef* FindFieldByName(const char *name) const {
+    return FindFieldByName(name, strlen(name));
+  }
+
+  template <class T>
+  FieldDef* FindFieldByName(const T& str) {
+    return FindFieldByName(str.c_str(), str.size());
+  }
+  template <class T>
+  const FieldDef* FindFieldByName(const T& str) const {
+    return FindFieldByName(str.c_str(), str.size());
+  }
+
+  // Returns a new msgdef that is a copy of the given msgdef (and a copy of all
+  // the fields) but with any references to submessages broken and replaced
+  // with just the name of the submessage.  Returns NULL if memory allocation
+  // failed.
+  //
+  // TODO(haberman): which is more useful, keeping fields resolved or
+  // unresolving them?  If there's no obvious answer, Should this functionality
+  // just be moved into symtab.c?
+  MessageDef* Dup(const void* owner) const;
+
+  // Iteration over fields.  The order is undefined.
+  class iterator : public std::iterator<std::forward_iterator_tag, FieldDef*> {
+   public:
+    explicit iterator(MessageDef* md);
+    static iterator end(MessageDef* md);
+
+    void operator++();
+    FieldDef* operator*() const;
+    bool operator!=(const iterator& other) const;
+    bool operator==(const iterator& other) const;
+
+   private:
+    upb_msg_iter iter_;
+  };
+
+  class const_iterator
+      : public std::iterator<std::forward_iterator_tag, const FieldDef*> {
+   public:
+    explicit const_iterator(const MessageDef* md);
+    static const_iterator end(const MessageDef* md);
+
+    void operator++();
+    const FieldDef* operator*() const;
+    bool operator!=(const const_iterator& other) const;
+    bool operator==(const const_iterator& other) const;
+
+   private:
+    upb_msg_iter iter_;
+  };
+
+  iterator begin();
+  iterator end();
+  const_iterator begin() const;
+  const_iterator end() const;
+
+ private:
+  UPB_DISALLOW_POD_OPS(MessageDef, upb::MessageDef);
+),
+UPB_DEFINE_STRUCT(upb_msgdef, upb_def,
+  size_t selector_count;
+  uint32_t submsg_field_count;
+
+  // Tables for looking up fields by number and name.
+  upb_inttable itof;  // int to field
+  upb_strtable ntof;  // name to field
+
+  // TODO(haberman): proper extension ranges (there can be multiple).
+));
+
+#define UPB_MSGDEF_INIT(name, selector_count, submsg_field_count, itof, ntof, \
+                        refs, ref2s)                                          \
+  {                                                                           \
+    UPB_DEF_INIT(name, UPB_DEF_MSG, refs, ref2s), selector_count,             \
+        submsg_field_count, itof, ntof                                        \
+  }
+
+UPB_BEGIN_EXTERN_C  // {
+
+// Returns NULL if memory allocation failed.
+upb_msgdef *upb_msgdef_new(const void *owner);
+
+// From upb_refcounted.
+bool upb_msgdef_isfrozen(const upb_msgdef *m);
+void upb_msgdef_ref(const upb_msgdef *m, const void *owner);
+void upb_msgdef_unref(const upb_msgdef *m, const void *owner);
+void upb_msgdef_donateref(const upb_msgdef *m, const void *from,
+                          const void *to);
+void upb_msgdef_checkref(const upb_msgdef *m, const void *owner);
+bool upb_msgdef_freeze(upb_msgdef *m, upb_status *status);
+
+// From upb_def.
+const char *upb_msgdef_fullname(const upb_msgdef *m);
+bool upb_msgdef_setfullname(upb_msgdef *m, const char *fullname, upb_status *s);
+
+upb_msgdef *upb_msgdef_dup(const upb_msgdef *m, const void *owner);
+bool upb_msgdef_addfield(upb_msgdef *m, upb_fielddef *f, const void *ref_donor,
+                         upb_status *s);
+
+// Field lookup in a couple of different variations:
+//   - itof = int to field
+//   - ntof = name to field
+//   - ntofz = name to field, null-terminated string.
+const upb_fielddef *upb_msgdef_itof(const upb_msgdef *m, uint32_t i);
+const upb_fielddef *upb_msgdef_ntof(const upb_msgdef *m, const char *name,
+                                    size_t len);
+int upb_msgdef_numfields(const upb_msgdef *m);
+
+UPB_INLINE const upb_fielddef *upb_msgdef_ntofz(const upb_msgdef *m,
+                                                const char *name) {
+  return upb_msgdef_ntof(m, name, strlen(name));
+}
+
+UPB_INLINE upb_fielddef *upb_msgdef_itof_mutable(upb_msgdef *m, uint32_t i) {
+  return (upb_fielddef*)upb_msgdef_itof(m, i);
+}
+
+UPB_INLINE upb_fielddef *upb_msgdef_ntof_mutable(upb_msgdef *m,
+                                                 const char *name, size_t len) {
+  return (upb_fielddef *)upb_msgdef_ntof(m, name, len);
+}
+
+// upb_msg_iter i;
+// for(upb_msg_begin(&i, m); !upb_msg_done(&i); upb_msg_next(&i)) {
+//   upb_fielddef *f = upb_msg_iter_field(&i);
+//   // ...
+// }
+//
+// For C we don't have separate iterators for const and non-const.
+// It is the caller's responsibility to cast the upb_fielddef* to
+// const if the upb_msgdef* is const.
+void upb_msg_begin(upb_msg_iter *iter, const upb_msgdef *m);
+void upb_msg_next(upb_msg_iter *iter);
+bool upb_msg_done(const upb_msg_iter *iter);
+upb_fielddef *upb_msg_iter_field(const upb_msg_iter *iter);
+void upb_msg_iter_setdone(upb_msg_iter *iter);
+
+UPB_END_EXTERN_C  // }
+
+
+/* upb::EnumDef ***************************************************************/
+
+typedef upb_strtable_iter upb_enum_iter;
+
+// Class that represents an enum.  Its base class is upb::Def (convert with
+// upb::upcast()).
+UPB_DEFINE_DEF(upb::EnumDef, enumdef, ENUM,
+ public:
+  // Returns NULL if memory allocation failed.
+  static reffed_ptr<EnumDef> New();
+
+  // Functionality from upb::RefCounted.
+  bool IsFrozen() const;
+  void Ref(const void* owner) const;
+  void Unref(const void* owner) const;
+  void DonateRef(const void* from, const void* to) const;
+  void CheckRef(const void* owner) const;
+
+  // Functionality from upb::Def.
+  const char* full_name() const;
+  bool set_full_name(const char* fullname, Status* s);
+  bool set_full_name(const std::string& fullname, Status* s);
+
+  // Call to freeze this EnumDef.
+  bool Freeze(Status* s);
+
+  // The value that is used as the default when no field default is specified.
+  // If not set explicitly, the first value that was added will be used.
+  // The default value must be a member of the enum.
+  // Requires that value_count() > 0.
+  int32_t default_value() const;
+
+  // Sets the default value.  If this value is not valid, returns false and an
+  // error message in status.
+  bool set_default_value(int32_t val, Status* status);
+
+  // Returns the number of values currently defined in the enum.  Note that
+  // multiple names can refer to the same number, so this may be greater than
+  // the total number of unique numbers.
+  int value_count() const;
+
+  // Adds a single name/number pair to the enum.  Fails if this name has
+  // already been used by another value.
+  bool AddValue(const char* name, int32_t num, Status* status);
+  bool AddValue(const std::string& name, int32_t num, Status* status);
+
+  // Lookups from name to integer, returning true if found.
+  bool FindValueByName(const char* name, int32_t* num) const;
+
+  // Finds the name corresponding to the given number, or NULL if none was
+  // found.  If more than one name corresponds to this number, returns the
+  // first one that was added.
+  const char* FindValueByNumber(int32_t num) const;
+
+  // Returns a new EnumDef with all the same values.  The new EnumDef will be
+  // owned by the given owner.
+  EnumDef* Dup(const void* owner) const;
+
+  // Iteration over name/value pairs.  The order is undefined.
+  // Adding an enum val invalidates any iterators.
+  //
+  // TODO: make compatible with range-for, with elements as pairs?
+  class Iterator {
+   public:
+    explicit Iterator(const EnumDef*);
+
+    int32_t number();
+    const char *name();
+    bool Done();
+    void Next();
+
+   private:
+    upb_enum_iter iter_;
+  };
+
+ private:
+  UPB_DISALLOW_POD_OPS(EnumDef, upb::EnumDef);
+,
+UPB_DEFINE_STRUCT(upb_enumdef, upb_def,
+  upb_strtable ntoi;
+  upb_inttable iton;
+  int32_t defaultval;
+));
+
+#define UPB_ENUMDEF_INIT(name, ntoi, iton, defaultval, refs, ref2s) \
+  { UPB_DEF_INIT(name, UPB_DEF_ENUM, refs, ref2s), ntoi, iton, defaultval }
+
+UPB_BEGIN_EXTERN_C  // {
+
+// Native C API.
+upb_enumdef *upb_enumdef_new(const void *owner);
+upb_enumdef *upb_enumdef_dup(const upb_enumdef *e, const void *owner);
+
+// From upb_refcounted.
+void upb_enumdef_unref(const upb_enumdef *e, const void *owner);
+bool upb_enumdef_isfrozen(const upb_enumdef *e);
+void upb_enumdef_ref(const upb_enumdef *e, const void *owner);
+void upb_enumdef_donateref(const upb_enumdef *m, const void *from,
+                           const void *to);
+void upb_enumdef_checkref(const upb_enumdef *e, const void *owner);
+bool upb_enumdef_freeze(upb_enumdef *e, upb_status *status);
+
+// From upb_def.
+const char *upb_enumdef_fullname(const upb_enumdef *e);
+bool upb_enumdef_setfullname(upb_enumdef *e, const char *fullname,
+                             upb_status *s);
+
+int32_t upb_enumdef_default(const upb_enumdef *e);
+bool upb_enumdef_setdefault(upb_enumdef *e, int32_t val, upb_status *s);
+int upb_enumdef_numvals(const upb_enumdef *e);
+bool upb_enumdef_addval(upb_enumdef *e, const char *name, int32_t num,
+                        upb_status *status);
+
+// Enum lookups:
+// - ntoi:  look up a name with specified length.
+// - ntoiz: look up a name provided as a null-terminated string.
+// - iton:  look up an integer, returning the name as a null-terminated string.
+bool upb_enumdef_ntoi(const upb_enumdef *e, const char *name, size_t len,
+                      int32_t *num);
+UPB_INLINE bool upb_enumdef_ntoiz(const upb_enumdef *e,
+                                  const char *name, int32_t *num) {
+  return upb_enumdef_ntoi(e, name, strlen(name), num);
+}
+const char *upb_enumdef_iton(const upb_enumdef *e, int32_t num);
+
+//  upb_enum_iter i;
+//  for(upb_enum_begin(&i, e); !upb_enum_done(&i); upb_enum_next(&i)) {
+//    // ...
+//  }
+void upb_enum_begin(upb_enum_iter *iter, const upb_enumdef *e);
+void upb_enum_next(upb_enum_iter *iter);
+bool upb_enum_done(upb_enum_iter *iter);
+const char *upb_enum_iter_name(upb_enum_iter *iter);
+int32_t upb_enum_iter_number(upb_enum_iter *iter);
+
+UPB_END_EXTERN_C  // }
+
+
+#ifdef __cplusplus
+
+UPB_INLINE const char* upb_safecstr(const std::string& str) {
+  assert(str.size() == std::strlen(str.c_str()));
+  return str.c_str();
+}
+
+// Inline C++ wrappers.
+namespace upb {
+
+inline Def* Def::Dup(const void* owner) const {
+  return upb_def_dup(this, owner);
+}
+inline bool Def::IsFrozen() const { return upb_def_isfrozen(this); }
+inline void Def::Ref(const void* owner) const { upb_def_ref(this, owner); }
+inline void Def::Unref(const void* owner) const { upb_def_unref(this, owner); }
+inline void Def::DonateRef(const void* from, const void* to) const {
+  upb_def_donateref(this, from, to);
+}
+inline void Def::CheckRef(const void* owner) const {
+  upb_def_checkref(this, owner);
+}
+inline Def::Type Def::def_type() const { return upb_def_type(this); }
+inline const char* Def::full_name() const { return upb_def_fullname(this); }
+inline bool Def::set_full_name(const char* fullname, Status* s) {
+  return upb_def_setfullname(this, fullname, s);
+}
+inline bool Def::set_full_name(const std::string& fullname, Status* s) {
+  return upb_def_setfullname(this, upb_safecstr(fullname), s);
+}
+inline bool Def::Freeze(Def* const* defs, int n, Status* status) {
+  return upb_def_freeze(defs, n, status);
+}
+inline bool Def::Freeze(const std::vector<Def*>& defs, Status* status) {
+  return upb_def_freeze((Def* const*)&defs[0], defs.size(), status);
+}
+
+inline bool FieldDef::CheckType(int32_t val) {
+  return upb_fielddef_checktype(val);
+}
+inline bool FieldDef::CheckLabel(int32_t val) {
+  return upb_fielddef_checklabel(val);
+}
+inline bool FieldDef::CheckDescriptorType(int32_t val) {
+  return upb_fielddef_checkdescriptortype(val);
+}
+inline bool FieldDef::CheckIntegerFormat(int32_t val) {
+  return upb_fielddef_checkintfmt(val);
+}
+inline FieldDef::Type FieldDef::ConvertType(int32_t val) {
+  assert(CheckType(val));
+  return static_cast<FieldDef::Type>(val);
+}
+inline FieldDef::Label FieldDef::ConvertLabel(int32_t val) {
+  assert(CheckLabel(val));
+  return static_cast<FieldDef::Label>(val);
+}
+inline FieldDef::DescriptorType FieldDef::ConvertDescriptorType(int32_t val) {
+  assert(CheckDescriptorType(val));
+  return static_cast<FieldDef::DescriptorType>(val);
+}
+inline FieldDef::IntegerFormat FieldDef::ConvertIntegerFormat(int32_t val) {
+  assert(CheckIntegerFormat(val));
+  return static_cast<FieldDef::IntegerFormat>(val);
+}
+
+inline reffed_ptr<FieldDef> FieldDef::New() {
+  upb_fielddef *f = upb_fielddef_new(&f);
+  return reffed_ptr<FieldDef>(f, &f);
+}
+inline FieldDef* FieldDef::Dup(const void* owner) const {
+  return upb_fielddef_dup(this, owner);
+}
+inline bool FieldDef::IsFrozen() const { return upb_fielddef_isfrozen(this); }
+inline void FieldDef::Ref(const void* owner) const {
+  upb_fielddef_ref(this, owner);
+}
+inline void FieldDef::Unref(const void* owner) const {
+  upb_fielddef_unref(this, owner);
+}
+inline void FieldDef::DonateRef(const void* from, const void* to) const {
+  upb_fielddef_donateref(this, from, to);
+}
+inline void FieldDef::CheckRef(const void* owner) const {
+  upb_fielddef_checkref(this, owner);
+}
+inline const char* FieldDef::full_name() const {
+  return upb_fielddef_fullname(this);
+}
+inline bool FieldDef::set_full_name(const char* fullname, Status* s) {
+  return upb_fielddef_setfullname(this, fullname, s);
+}
+inline bool FieldDef::set_full_name(const std::string& fullname, Status* s) {
+  return upb_fielddef_setfullname(this, upb_safecstr(fullname), s);
+}
+inline bool FieldDef::type_is_set() const {
+  return upb_fielddef_typeisset(this);
+}
+inline FieldDef::Type FieldDef::type() const { return upb_fielddef_type(this); }
+inline FieldDef::DescriptorType FieldDef::descriptor_type() const {
+  return upb_fielddef_descriptortype(this);
+}
+inline FieldDef::Label FieldDef::label() const {
+  return upb_fielddef_label(this);
+}
+inline uint32_t FieldDef::number() const { return upb_fielddef_number(this); }
+inline const char* FieldDef::name() const { return upb_fielddef_name(this); }
+inline bool FieldDef::is_extension() const {
+  return upb_fielddef_isextension(this);
+}
+inline bool FieldDef::lazy() const {
+  return upb_fielddef_lazy(this);
+}
+inline void FieldDef::set_lazy(bool lazy) {
+  upb_fielddef_setlazy(this, lazy);
+}
+inline bool FieldDef::packed() const {
+  return upb_fielddef_packed(this);
+}
+inline void FieldDef::set_packed(bool packed) {
+  upb_fielddef_setpacked(this, packed);
+}
+inline const MessageDef* FieldDef::containing_type() const {
+  return upb_fielddef_containingtype(this);
+}
+inline const char* FieldDef::containing_type_name() {
+  return upb_fielddef_containingtypename(this);
+}
+inline bool FieldDef::set_number(uint32_t number, Status* s) {
+  return upb_fielddef_setnumber(this, number, s);
+}
+inline bool FieldDef::set_name(const char *name, Status* s) {
+  return upb_fielddef_setname(this, name, s);
+}
+inline bool FieldDef::set_name(const std::string& name, Status* s) {
+  return upb_fielddef_setname(this, upb_safecstr(name), s);
+}
+inline bool FieldDef::set_containing_type_name(const char *name, Status* s) {
+  return upb_fielddef_setcontainingtypename(this, name, s);
+}
+inline bool FieldDef::set_containing_type_name(const std::string &name,
+                                               Status *s) {
+  return upb_fielddef_setcontainingtypename(this, upb_safecstr(name), s);
+}
+inline void FieldDef::set_type(upb_fieldtype_t type) {
+  upb_fielddef_settype(this, type);
+}
+inline void FieldDef::set_is_extension(bool is_extension) {
+  upb_fielddef_setisextension(this, is_extension);
+}
+inline void FieldDef::set_descriptor_type(FieldDef::DescriptorType type) {
+  upb_fielddef_setdescriptortype(this, type);
+}
+inline void FieldDef::set_label(upb_label_t label) {
+  upb_fielddef_setlabel(this, label);
+}
+inline bool FieldDef::IsSubMessage() const {
+  return upb_fielddef_issubmsg(this);
+}
+inline bool FieldDef::IsString() const { return upb_fielddef_isstring(this); }
+inline bool FieldDef::IsSequence() const { return upb_fielddef_isseq(this); }
+inline int64_t FieldDef::default_int64() const {
+  return upb_fielddef_defaultint64(this);
+}
+inline int32_t FieldDef::default_int32() const {
+  return upb_fielddef_defaultint32(this);
+}
+inline uint64_t FieldDef::default_uint64() const {
+  return upb_fielddef_defaultuint64(this);
+}
+inline uint32_t FieldDef::default_uint32() const {
+  return upb_fielddef_defaultuint32(this);
+}
+inline bool FieldDef::default_bool() const {
+  return upb_fielddef_defaultbool(this);
+}
+inline float FieldDef::default_float() const {
+  return upb_fielddef_defaultfloat(this);
+}
+inline double FieldDef::default_double() const {
+  return upb_fielddef_defaultdouble(this);
+}
+inline const char* FieldDef::default_string(size_t* len) const {
+  return upb_fielddef_defaultstr(this, len);
+}
+inline void FieldDef::set_default_int64(int64_t value) {
+  upb_fielddef_setdefaultint64(this, value);
+}
+inline void FieldDef::set_default_int32(int32_t value) {
+  upb_fielddef_setdefaultint32(this, value);
+}
+inline void FieldDef::set_default_uint64(uint64_t value) {
+  upb_fielddef_setdefaultuint64(this, value);
+}
+inline void FieldDef::set_default_uint32(uint32_t value) {
+  upb_fielddef_setdefaultuint32(this, value);
+}
+inline void FieldDef::set_default_bool(bool value) {
+  upb_fielddef_setdefaultbool(this, value);
+}
+inline void FieldDef::set_default_float(float value) {
+  upb_fielddef_setdefaultfloat(this, value);
+}
+inline void FieldDef::set_default_double(double value) {
+  upb_fielddef_setdefaultdouble(this, value);
+}
+inline bool FieldDef::set_default_string(const void *str, size_t len,
+                                         Status *s) {
+  return upb_fielddef_setdefaultstr(this, str, len, s);
+}
+inline bool FieldDef::set_default_string(const std::string& str, Status* s) {
+  return upb_fielddef_setdefaultstr(this, str.c_str(), str.size(), s);
+}
+inline void FieldDef::set_default_cstr(const char* str, Status* s) {
+  return upb_fielddef_setdefaultcstr(this, str, s);
+}
+inline bool FieldDef::HasSubDef() const { return upb_fielddef_hassubdef(this); }
+inline const Def* FieldDef::subdef() const { return upb_fielddef_subdef(this); }
+inline const MessageDef *FieldDef::message_subdef() const {
+  return upb_fielddef_msgsubdef(this);
+}
+inline const EnumDef *FieldDef::enum_subdef() const {
+  return upb_fielddef_enumsubdef(this);
+}
+inline const char* FieldDef::subdef_name() const {
+  return upb_fielddef_subdefname(this);
+}
+inline bool FieldDef::set_subdef(const Def* subdef, Status* s) {
+  return upb_fielddef_setsubdef(this, subdef, s);
+}
+inline bool FieldDef::set_enum_subdef(const EnumDef* subdef, Status* s) {
+  return upb_fielddef_setenumsubdef(this, subdef, s);
+}
+inline bool FieldDef::set_message_subdef(const MessageDef* subdef, Status* s) {
+  return upb_fielddef_setmsgsubdef(this, subdef, s);
+}
+inline bool FieldDef::set_subdef_name(const char* name, Status* s) {
+  return upb_fielddef_setsubdefname(this, name, s);
+}
+inline bool FieldDef::set_subdef_name(const std::string& name, Status* s) {
+  return upb_fielddef_setsubdefname(this, upb_safecstr(name), s);
+}
+
+inline reffed_ptr<MessageDef> MessageDef::New() {
+  upb_msgdef *m = upb_msgdef_new(&m);
+  return reffed_ptr<MessageDef>(m, &m);
+}
+inline bool MessageDef::IsFrozen() const { return upb_msgdef_isfrozen(this); }
+inline void MessageDef::Ref(const void* owner) const {
+  return upb_msgdef_ref(this, owner);
+}
+inline void MessageDef::Unref(const void* owner) const {
+  return upb_msgdef_unref(this, owner);
+}
+inline void MessageDef::DonateRef(const void* from, const void* to) const {
+  return upb_msgdef_donateref(this, from, to);
+}
+inline void MessageDef::CheckRef(const void* owner) const {
+  return upb_msgdef_checkref(this, owner);
+}
+inline const char *MessageDef::full_name() const {
+  return upb_msgdef_fullname(this);
+}
+inline bool MessageDef::set_full_name(const char* fullname, Status* s) {
+  return upb_msgdef_setfullname(this, fullname, s);
+}
+inline bool MessageDef::set_full_name(const std::string& fullname, Status* s) {
+  return upb_msgdef_setfullname(this, upb_safecstr(fullname), s);
+}
+inline bool MessageDef::Freeze(Status* status) {
+  return upb_msgdef_freeze(this, status);
+}
+inline int MessageDef::field_count() const {
+  return upb_msgdef_numfields(this);
+}
+inline bool MessageDef::AddField(upb_fielddef* f, Status* s) {
+  return upb_msgdef_addfield(this, f, NULL, s);
+}
+inline bool MessageDef::AddField(const reffed_ptr<FieldDef>& f, Status* s) {
+  return upb_msgdef_addfield(this, f.get(), NULL, s);
+}
+inline FieldDef* MessageDef::FindFieldByNumber(uint32_t number) {
+  return upb_msgdef_itof_mutable(this, number);
+}
+inline FieldDef* MessageDef::FindFieldByName(const char* name, size_t len) {
+  return upb_msgdef_ntof_mutable(this, name, len);
+}
+inline const FieldDef* MessageDef::FindFieldByNumber(uint32_t number) const {
+  return upb_msgdef_itof(this, number);
+}
+inline const FieldDef *MessageDef::FindFieldByName(const char *name,
+                                                   size_t len) const {
+  return upb_msgdef_ntof(this, name, len);
+}
+inline MessageDef* MessageDef::Dup(const void *owner) const {
+  return upb_msgdef_dup(this, owner);
+}
+inline MessageDef::iterator MessageDef::begin() { return iterator(this); }
+inline MessageDef::iterator MessageDef::end() { return iterator::end(this); }
+inline MessageDef::const_iterator MessageDef::begin() const {
+  return const_iterator(this);
+}
+inline MessageDef::const_iterator MessageDef::end() const {
+  return const_iterator::end(this);
+}
+
+inline MessageDef::iterator::iterator(MessageDef* md) {
+  upb_msg_begin(&iter_, md);
+}
+inline MessageDef::iterator MessageDef::iterator::end(MessageDef* md) {
+  MessageDef::iterator iter(md);
+  upb_msg_iter_setdone(&iter.iter_);
+  return iter;
+}
+inline FieldDef* MessageDef::iterator::operator*() const {
+  return upb_msg_iter_field(&iter_);
+}
+inline void MessageDef::iterator::operator++() { return upb_msg_next(&iter_); }
+inline bool MessageDef::iterator::operator==(const iterator &other) const {
+  return upb_inttable_iter_isequal(&iter_, &other.iter_);
+}
+inline bool MessageDef::iterator::operator!=(const iterator &other) const {
+  return !(*this == other);
+}
+
+inline MessageDef::const_iterator::const_iterator(const MessageDef* md) {
+  upb_msg_begin(&iter_, md);
+}
+inline MessageDef::const_iterator MessageDef::const_iterator::end(
+    const MessageDef *md) {
+  MessageDef::const_iterator iter(md);
+  upb_msg_iter_setdone(&iter.iter_);
+  return iter;
+}
+inline const FieldDef* MessageDef::const_iterator::operator*() const {
+  return upb_msg_iter_field(&iter_);
+}
+inline void MessageDef::const_iterator::operator++() {
+  return upb_msg_next(&iter_);
+}
+inline bool MessageDef::const_iterator::operator==(
+    const const_iterator &other) const {
+  return upb_inttable_iter_isequal(&iter_, &other.iter_);
+}
+inline bool MessageDef::const_iterator::operator!=(
+    const const_iterator &other) const {
+  return !(*this == other);
+}
+
+inline reffed_ptr<EnumDef> EnumDef::New() {
+  upb_enumdef *e = upb_enumdef_new(&e);
+  return reffed_ptr<EnumDef>(e, &e);
+}
+inline bool EnumDef::IsFrozen() const { return upb_enumdef_isfrozen(this); }
+inline void EnumDef::Ref(const void* owner) const {
+  return upb_enumdef_ref(this, owner);
+}
+inline void EnumDef::Unref(const void* owner) const {
+  return upb_enumdef_unref(this, owner);
+}
+inline void EnumDef::DonateRef(const void* from, const void* to) const {
+  return upb_enumdef_donateref(this, from, to);
+}
+inline void EnumDef::CheckRef(const void* owner) const {
+  return upb_enumdef_checkref(this, owner);
+}
+inline const char* EnumDef::full_name() const {
+  return upb_enumdef_fullname(this);
+}
+inline bool EnumDef::set_full_name(const char* fullname, Status* s) {
+  return upb_enumdef_setfullname(this, fullname, s);
+}
+inline bool EnumDef::set_full_name(const std::string& fullname, Status* s) {
+  return upb_enumdef_setfullname(this, upb_safecstr(fullname), s);
+}
+inline bool EnumDef::Freeze(Status* status) {
+  return upb_enumdef_freeze(this, status);
+}
+inline int32_t EnumDef::default_value() const {
+  return upb_enumdef_default(this);
+}
+inline bool EnumDef::set_default_value(int32_t val, Status* status) {
+  return upb_enumdef_setdefault(this, val, status);
+}
+inline int EnumDef::value_count() const { return upb_enumdef_numvals(this); }
+inline bool EnumDef::AddValue(const char* name, int32_t num, Status* status) {
+  return upb_enumdef_addval(this, name, num, status);
+}
+inline bool EnumDef::AddValue(const std::string& name, int32_t num,
+                              Status* status) {
+  return upb_enumdef_addval(this, upb_safecstr(name), num, status);
+}
+inline bool EnumDef::FindValueByName(const char* name, int32_t *num) const {
+  return upb_enumdef_ntoiz(this, name, num);
+}
+inline const char* EnumDef::FindValueByNumber(int32_t num) const {
+  return upb_enumdef_iton(this, num);
+}
+inline EnumDef* EnumDef::Dup(const void* owner) const {
+  return upb_enumdef_dup(this, owner);
+}
+
+inline EnumDef::Iterator::Iterator(const EnumDef* e) {
+  upb_enum_begin(&iter_, e);
+}
+inline int32_t EnumDef::Iterator::number() {
+  return upb_enum_iter_number(&iter_);
+}
+inline const char* EnumDef::Iterator::name() {
+  return upb_enum_iter_name(&iter_);
+}
+inline bool EnumDef::Iterator::Done() { return upb_enum_done(&iter_); }
+inline void EnumDef::Iterator::Next() { return upb_enum_next(&iter_); }
+}  // namespace upb
+#endif
+
+#undef UPB_DEFINE_DEF
+#undef UPB_DEF_CASTS
+#undef UPB_CPP_CASTS
+
+#endif /* UPB_DEF_H_ */
+// This file contains accessors for a set of compiled-in defs.
+// Note that unlike Google's protobuf, it does *not* define
+// generated classes or any other kind of data structure for
+// actually storing protobufs.  It only contains *defs* which
+// let you reflect over a protobuf *schema*.
+//
+// This file was generated by upbc (the upb compiler).
+// Do not edit -- your changes will be discarded when the file is
+// regenerated.
+
+#ifndef GOOGLE_PROTOBUF_DESCRIPTOR_UPB_H_
+#define GOOGLE_PROTOBUF_DESCRIPTOR_UPB_H_
+
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009-2012 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * A symtab (symbol table) stores a name->def map of upb_defs.  Clients could
+ * always create such tables themselves, but upb_symtab has logic for resolving
+ * symbolic references, and in particular, for keeping a whole set of consistent
+ * defs when replacing some subset of those defs.  This logic is nontrivial.
+ *
+ * This is a mixed C/C++ interface that offers a full API to both languages.
+ * See the top-level README for more information.
+ */
+
+#ifndef UPB_SYMTAB_H_
+#define UPB_SYMTAB_H_
+
+
+#ifdef __cplusplus
+#include <vector>
+namespace upb { class SymbolTable; }
+#endif
+
+UPB_DECLARE_TYPE(upb::SymbolTable, upb_symtab);
+
+typedef struct {
+ UPB_PRIVATE_FOR_CPP
+  upb_strtable_iter iter;
+  upb_deftype_t type;
+} upb_symtab_iter;
+
+// Non-const methods in upb::SymbolTable are NOT thread-safe.
+UPB_DEFINE_CLASS1(upb::SymbolTable, upb::RefCounted,
+ public:
+  // Returns a new symbol table with a single ref owned by "owner."
+  // Returns NULL if memory allocation failed.
+  static reffed_ptr<SymbolTable> New();
+
+  // Functionality from upb::RefCounted.
+  bool IsFrozen() const;
+  void Ref(const void* owner) const;
+  void Unref(const void* owner) const;
+  void DonateRef(const void *from, const void *to) const;
+  void CheckRef(const void *owner) const;
+
+  // For all lookup functions, the returned pointer is not owned by the
+  // caller; it may be invalidated by any non-const call or unref of the
+  // SymbolTable!  To protect against this, take a ref if desired.
+
+  // Freezes the symbol table: prevents further modification of it.
+  // After the Freeze() operation is successful, the SymbolTable must only be
+  // accessed via a const pointer.
+  //
+  // Unlike with upb::MessageDef/upb::EnumDef/etc, freezing a SymbolTable is not
+  // a necessary step in using a SymbolTable.  If you have no need for it to be
+  // immutable, there is no need to freeze it ever.  However sometimes it is
+  // useful, and SymbolTables that are statically compiled into the binary are
+  // always frozen by nature.
+  void Freeze();
+
+  // Resolves the given symbol using the rules described in descriptor.proto,
+  // namely:
+  //
+  //    If the name starts with a '.', it is fully-qualified.  Otherwise,
+  //    C++-like scoping rules are used to find the type (i.e. first the nested
+  //    types within this message are searched, then within the parent, on up
+  //    to the root namespace).
+  //
+  // If not found, returns NULL.
+  const Def* Resolve(const char* base, const char* sym) const;
+
+  // Finds an entry in the symbol table with this exact name.  If not found,
+  // returns NULL.
+  const Def* Lookup(const char *sym) const;
+  const MessageDef* LookupMessage(const char *sym) const;
+  const EnumDef* LookupEnum(const char *sym) const;
+
+  // TODO: introduce a C++ iterator, but make it nice and templated so that if
+  // you ask for an iterator of MessageDef the iterated elements are strongly
+  // typed as MessageDef*.
+
+  // Adds the given mutable defs to the symtab, resolving all symbols
+  // (including enum default values) and finalizing the defs.  Only one def per
+  // name may be in the list, but defs can replace existing defs in the symtab.
+  // All defs must have a name -- anonymous defs are not allowed.  Anonymous
+  // defs can still be frozen by calling upb_def_freeze() directly.
+  //
+  // Any existing defs that can reach defs that are being replaced will
+  // themselves be replaced also, so that the resulting set of defs is fully
+  // consistent.
+  //
+  // This logic implemented in this method is a convenience; ultimately it
+  // calls some combination of upb_fielddef_setsubdef(), upb_def_dup(), and
+  // upb_freeze(), any of which the client could call themself.  However, since
+  // the logic for doing so is nontrivial, we provide it here.
+  //
+  // The entire operation either succeeds or fails.  If the operation fails,
+  // the symtab is unchanged, false is returned, and status indicates the
+  // error.  The caller passes a ref on all defs to the symtab (even if the
+  // operation fails).
+  //
+  // TODO(haberman): currently failure will leave the symtab unchanged, but may
+  // leave the defs themselves partially resolved.  Does this matter?  If so we
+  // could do a prepass that ensures that all symbols are resolvable and bail
+  // if not, so we don't mutate anything until we know the operation will
+  // succeed.
+  //
+  // TODO(haberman): since the defs must be mutable, refining a frozen def
+  // requires making mutable copies of the entire tree.  This is wasteful if
+  // only a few messages are changing.  We may want to add a way of adding a
+  // tree of frozen defs to the symtab (perhaps an alternate constructor where
+  // you pass the root of the tree?)
+  bool Add(Def*const* defs, int n, void* ref_donor, upb_status* status);
+
+  bool Add(const std::vector<Def*>& defs, void *owner, Status* status) {
+    return Add((Def*const*)&defs[0], defs.size(), owner, status);
+  }
+
+ private:
+  UPB_DISALLOW_POD_OPS(SymbolTable, upb::SymbolTable);
+,
+UPB_DEFINE_STRUCT(upb_symtab, upb_refcounted,
+  upb_strtable symtab;
+));
+
+#define UPB_SYMTAB_INIT(symtab, refs, ref2s) \
+  { UPB_REFCOUNT_INIT(refs, ref2s), symtab }
+
+UPB_BEGIN_EXTERN_C  // {
+
+// Native C API.
+// From upb_refcounted.
+bool upb_symtab_isfrozen(const upb_symtab *s);
+void upb_symtab_ref(const upb_symtab *s, const void *owner);
+void upb_symtab_unref(const upb_symtab *s, const void *owner);
+void upb_symtab_donateref(
+    const upb_symtab *s, const void *from, const void *to);
+void upb_symtab_checkref(const upb_symtab *s, const void *owner);
+
+upb_symtab *upb_symtab_new(const void *owner);
+void upb_symtab_freeze(upb_symtab *s);
+const upb_def *upb_symtab_resolve(const upb_symtab *s, const char *base,
+                                  const char *sym);
+const upb_def *upb_symtab_lookup(const upb_symtab *s, const char *sym);
+const upb_msgdef *upb_symtab_lookupmsg(const upb_symtab *s, const char *sym);
+const upb_enumdef *upb_symtab_lookupenum(const upb_symtab *s, const char *sym);
+bool upb_symtab_add(upb_symtab *s, upb_def *const*defs, int n, void *ref_donor,
+                    upb_status *status);
+
+// upb_symtab_iter i;
+// for(upb_symtab_begin(&i, s, type); !upb_symtab_done(&i);
+//     upb_symtab_next(&i)) {
+//   const upb_def *def = upb_symtab_iter_def(&i);
+//   // ...
+// }
+//
+// For C we don't have separate iterators for const and non-const.
+// It is the caller's responsibility to cast the upb_fielddef* to
+// const if the upb_msgdef* is const.
+void upb_symtab_begin(upb_symtab_iter *iter, const upb_symtab *s,
+                      upb_deftype_t type);
+void upb_symtab_next(upb_symtab_iter *iter);
+bool upb_symtab_done(const upb_symtab_iter *iter);
+const upb_def *upb_symtab_iter_def(const upb_symtab_iter *iter);
+
+UPB_END_EXTERN_C  // }
+
+#ifdef __cplusplus
+// C++ inline wrappers.
+namespace upb {
+inline reffed_ptr<SymbolTable> SymbolTable::New() {
+  upb_symtab *s = upb_symtab_new(&s);
+  return reffed_ptr<SymbolTable>(s, &s);
+}
+
+inline bool SymbolTable::IsFrozen() const {
+  return upb_symtab_isfrozen(this);
+}
+inline void SymbolTable::Ref(const void *owner) const {
+  upb_symtab_ref(this, owner);
+}
+inline void SymbolTable::Unref(const void *owner) const {
+  upb_symtab_unref(this, owner);
+}
+inline void SymbolTable::DonateRef(const void *from, const void *to) const {
+  upb_symtab_donateref(this, from, to);
+}
+inline void SymbolTable::CheckRef(const void *owner) const {
+  upb_symtab_checkref(this, owner);
+}
+
+inline void SymbolTable::Freeze() {
+  return upb_symtab_freeze(this);
+}
+inline const Def *SymbolTable::Resolve(const char *base,
+                                       const char *sym) const {
+  return upb_symtab_resolve(this, base, sym);
+}
+inline const Def* SymbolTable::Lookup(const char *sym) const {
+  return upb_symtab_lookup(this, sym);
+}
+inline const MessageDef *SymbolTable::LookupMessage(const char *sym) const {
+  return upb_symtab_lookupmsg(this, sym);
+}
+inline bool SymbolTable::Add(
+    Def*const* defs, int n, void* ref_donor, upb_status* status) {
+  return upb_symtab_add(this, (upb_def*const*)defs, n, ref_donor, status);
+}
+}  // namespace upb
+#endif
+
+#endif  /* UPB_SYMTAB_H_ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Enums
+
+typedef enum {
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_LABEL_OPTIONAL = 1,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_LABEL_REQUIRED = 2,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_LABEL_REPEATED = 3,
+} google_protobuf_FieldDescriptorProto_Label;
+
+typedef enum {
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_DOUBLE = 1,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_FLOAT = 2,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_INT64 = 3,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_UINT64 = 4,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_INT32 = 5,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_FIXED64 = 6,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_FIXED32 = 7,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_BOOL = 8,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_STRING = 9,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_GROUP = 10,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_MESSAGE = 11,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_BYTES = 12,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_UINT32 = 13,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_ENUM = 14,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_SFIXED32 = 15,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_SFIXED64 = 16,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_SINT32 = 17,
+  GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_SINT64 = 18,
+} google_protobuf_FieldDescriptorProto_Type;
+
+typedef enum {
+  GOOGLE_PROTOBUF_FIELDOPTIONS_STRING = 0,
+  GOOGLE_PROTOBUF_FIELDOPTIONS_CORD = 1,
+  GOOGLE_PROTOBUF_FIELDOPTIONS_STRING_PIECE = 2,
+} google_protobuf_FieldOptions_CType;
+
+typedef enum {
+  GOOGLE_PROTOBUF_FILEOPTIONS_SPEED = 1,
+  GOOGLE_PROTOBUF_FILEOPTIONS_CODE_SIZE = 2,
+  GOOGLE_PROTOBUF_FILEOPTIONS_LITE_RUNTIME = 3,
+} google_protobuf_FileOptions_OptimizeMode;
+
+// Selectors
+
+// google.protobuf.DescriptorProto
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_FIELD_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_NESTED_TYPE_STARTSUBMSG 3
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_ENUM_TYPE_STARTSUBMSG 4
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_EXTENSION_RANGE_STARTSUBMSG 5
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_EXTENSION_STARTSUBMSG 6
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_OPTIONS_STARTSUBMSG 7
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_FIELD_STARTSEQ 8
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_FIELD_ENDSEQ 9
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_FIELD_ENDSUBMSG 10
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_NESTED_TYPE_STARTSEQ 11
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_NESTED_TYPE_ENDSEQ 12
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_NESTED_TYPE_ENDSUBMSG 13
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_ENUM_TYPE_STARTSEQ 14
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_ENUM_TYPE_ENDSEQ 15
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_ENUM_TYPE_ENDSUBMSG 16
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_EXTENSION_RANGE_STARTSEQ 17
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_EXTENSION_RANGE_ENDSEQ 18
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_EXTENSION_RANGE_ENDSUBMSG 19
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_EXTENSION_STARTSEQ 20
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_EXTENSION_ENDSEQ 21
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_EXTENSION_ENDSUBMSG 22
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_OPTIONS_ENDSUBMSG 23
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_NAME_STRING 24
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_NAME_STARTSTR 25
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_NAME_ENDSTR 26
+
+// google.protobuf.DescriptorProto.ExtensionRange
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_EXTENSIONRANGE_START_INT32 2
+#define SEL_GOOGLE_PROTOBUF_DESCRIPTORPROTO_EXTENSIONRANGE_END_INT32 3
+
+// google.protobuf.EnumDescriptorProto
+#define SEL_GOOGLE_PROTOBUF_ENUMDESCRIPTORPROTO_VALUE_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_ENUMDESCRIPTORPROTO_OPTIONS_STARTSUBMSG 3
+#define SEL_GOOGLE_PROTOBUF_ENUMDESCRIPTORPROTO_VALUE_STARTSEQ 4
+#define SEL_GOOGLE_PROTOBUF_ENUMDESCRIPTORPROTO_VALUE_ENDSEQ 5
+#define SEL_GOOGLE_PROTOBUF_ENUMDESCRIPTORPROTO_VALUE_ENDSUBMSG 6
+#define SEL_GOOGLE_PROTOBUF_ENUMDESCRIPTORPROTO_OPTIONS_ENDSUBMSG 7
+#define SEL_GOOGLE_PROTOBUF_ENUMDESCRIPTORPROTO_NAME_STRING 8
+#define SEL_GOOGLE_PROTOBUF_ENUMDESCRIPTORPROTO_NAME_STARTSTR 9
+#define SEL_GOOGLE_PROTOBUF_ENUMDESCRIPTORPROTO_NAME_ENDSTR 10
+
+// google.protobuf.EnumOptions
+#define SEL_GOOGLE_PROTOBUF_ENUMOPTIONS_UNINTERPRETED_OPTION_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_ENUMOPTIONS_UNINTERPRETED_OPTION_STARTSEQ 3
+#define SEL_GOOGLE_PROTOBUF_ENUMOPTIONS_UNINTERPRETED_OPTION_ENDSEQ 4
+#define SEL_GOOGLE_PROTOBUF_ENUMOPTIONS_UNINTERPRETED_OPTION_ENDSUBMSG 5
+#define SEL_GOOGLE_PROTOBUF_ENUMOPTIONS_ALLOW_ALIAS_BOOL 6
+
+// google.protobuf.EnumValueDescriptorProto
+#define SEL_GOOGLE_PROTOBUF_ENUMVALUEDESCRIPTORPROTO_OPTIONS_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_ENUMVALUEDESCRIPTORPROTO_OPTIONS_ENDSUBMSG 3
+#define SEL_GOOGLE_PROTOBUF_ENUMVALUEDESCRIPTORPROTO_NAME_STRING 4
+#define SEL_GOOGLE_PROTOBUF_ENUMVALUEDESCRIPTORPROTO_NAME_STARTSTR 5
+#define SEL_GOOGLE_PROTOBUF_ENUMVALUEDESCRIPTORPROTO_NAME_ENDSTR 6
+#define SEL_GOOGLE_PROTOBUF_ENUMVALUEDESCRIPTORPROTO_NUMBER_INT32 7
+
+// google.protobuf.EnumValueOptions
+#define SEL_GOOGLE_PROTOBUF_ENUMVALUEOPTIONS_UNINTERPRETED_OPTION_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_ENUMVALUEOPTIONS_UNINTERPRETED_OPTION_STARTSEQ 3
+#define SEL_GOOGLE_PROTOBUF_ENUMVALUEOPTIONS_UNINTERPRETED_OPTION_ENDSEQ 4
+#define SEL_GOOGLE_PROTOBUF_ENUMVALUEOPTIONS_UNINTERPRETED_OPTION_ENDSUBMSG 5
+
+// google.protobuf.FieldDescriptorProto
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_OPTIONS_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_OPTIONS_ENDSUBMSG 3
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_NAME_STRING 4
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_NAME_STARTSTR 5
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_NAME_ENDSTR 6
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_EXTENDEE_STRING 7
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_EXTENDEE_STARTSTR 8
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_EXTENDEE_ENDSTR 9
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_NUMBER_INT32 10
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_LABEL_INT32 11
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_INT32 12
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_NAME_STRING 13
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_NAME_STARTSTR 14
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_TYPE_NAME_ENDSTR 15
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_DEFAULT_VALUE_STRING 16
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_DEFAULT_VALUE_STARTSTR 17
+#define SEL_GOOGLE_PROTOBUF_FIELDDESCRIPTORPROTO_DEFAULT_VALUE_ENDSTR 18
+
+// google.protobuf.FieldOptions
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_UNINTERPRETED_OPTION_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_UNINTERPRETED_OPTION_STARTSEQ 3
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_UNINTERPRETED_OPTION_ENDSEQ 4
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_UNINTERPRETED_OPTION_ENDSUBMSG 5
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_CTYPE_INT32 6
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_PACKED_BOOL 7
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_DEPRECATED_BOOL 8
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_LAZY_BOOL 9
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_EXPERIMENTAL_MAP_KEY_STRING 10
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_EXPERIMENTAL_MAP_KEY_STARTSTR 11
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_EXPERIMENTAL_MAP_KEY_ENDSTR 12
+#define SEL_GOOGLE_PROTOBUF_FIELDOPTIONS_WEAK_BOOL 13
+
+// google.protobuf.FileDescriptorProto
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_MESSAGE_TYPE_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_ENUM_TYPE_STARTSUBMSG 3
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_SERVICE_STARTSUBMSG 4
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_EXTENSION_STARTSUBMSG 5
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_OPTIONS_STARTSUBMSG 6
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_SOURCE_CODE_INFO_STARTSUBMSG 7
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_MESSAGE_TYPE_STARTSEQ 8
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_MESSAGE_TYPE_ENDSEQ 9
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_MESSAGE_TYPE_ENDSUBMSG 10
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_ENUM_TYPE_STARTSEQ 11
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_ENUM_TYPE_ENDSEQ 12
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_ENUM_TYPE_ENDSUBMSG 13
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_SERVICE_STARTSEQ 14
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_SERVICE_ENDSEQ 15
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_SERVICE_ENDSUBMSG 16
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_EXTENSION_STARTSEQ 17
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_EXTENSION_ENDSEQ 18
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_EXTENSION_ENDSUBMSG 19
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_OPTIONS_ENDSUBMSG 20
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_SOURCE_CODE_INFO_ENDSUBMSG 21
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_NAME_STRING 22
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_NAME_STARTSTR 23
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_NAME_ENDSTR 24
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_PACKAGE_STRING 25
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_PACKAGE_STARTSTR 26
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_PACKAGE_ENDSTR 27
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_DEPENDENCY_STARTSEQ 28
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_DEPENDENCY_ENDSEQ 29
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_DEPENDENCY_STRING 30
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_DEPENDENCY_STARTSTR 31
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_DEPENDENCY_ENDSTR 32
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_PUBLIC_DEPENDENCY_STARTSEQ 33
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_PUBLIC_DEPENDENCY_ENDSEQ 34
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_PUBLIC_DEPENDENCY_INT32 35
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_WEAK_DEPENDENCY_STARTSEQ 36
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_WEAK_DEPENDENCY_ENDSEQ 37
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORPROTO_WEAK_DEPENDENCY_INT32 38
+
+// google.protobuf.FileDescriptorSet
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORSET_FILE_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORSET_FILE_STARTSEQ 3
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORSET_FILE_ENDSEQ 4
+#define SEL_GOOGLE_PROTOBUF_FILEDESCRIPTORSET_FILE_ENDSUBMSG 5
+
+// google.protobuf.FileOptions
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_UNINTERPRETED_OPTION_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_UNINTERPRETED_OPTION_STARTSEQ 3
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_UNINTERPRETED_OPTION_ENDSEQ 4
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_UNINTERPRETED_OPTION_ENDSUBMSG 5
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_JAVA_PACKAGE_STRING 6
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_JAVA_PACKAGE_STARTSTR 7
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_JAVA_PACKAGE_ENDSTR 8
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_JAVA_OUTER_CLASSNAME_STRING 9
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_JAVA_OUTER_CLASSNAME_STARTSTR 10
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_JAVA_OUTER_CLASSNAME_ENDSTR 11
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_OPTIMIZE_FOR_INT32 12
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_JAVA_MULTIPLE_FILES_BOOL 13
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_GO_PACKAGE_STRING 14
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_GO_PACKAGE_STARTSTR 15
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_GO_PACKAGE_ENDSTR 16
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_CC_GENERIC_SERVICES_BOOL 17
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_JAVA_GENERIC_SERVICES_BOOL 18
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_PY_GENERIC_SERVICES_BOOL 19
+#define SEL_GOOGLE_PROTOBUF_FILEOPTIONS_JAVA_GENERATE_EQUALS_AND_HASH_BOOL 20
+
+// google.protobuf.MessageOptions
+#define SEL_GOOGLE_PROTOBUF_MESSAGEOPTIONS_UNINTERPRETED_OPTION_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_MESSAGEOPTIONS_UNINTERPRETED_OPTION_STARTSEQ 3
+#define SEL_GOOGLE_PROTOBUF_MESSAGEOPTIONS_UNINTERPRETED_OPTION_ENDSEQ 4
+#define SEL_GOOGLE_PROTOBUF_MESSAGEOPTIONS_UNINTERPRETED_OPTION_ENDSUBMSG 5
+#define SEL_GOOGLE_PROTOBUF_MESSAGEOPTIONS_MESSAGE_SET_WIRE_FORMAT_BOOL 6
+#define SEL_GOOGLE_PROTOBUF_MESSAGEOPTIONS_NO_STANDARD_DESCRIPTOR_ACCESSOR_BOOL 7
+
+// google.protobuf.MethodDescriptorProto
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_OPTIONS_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_OPTIONS_ENDSUBMSG 3
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_NAME_STRING 4
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_NAME_STARTSTR 5
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_NAME_ENDSTR 6
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_INPUT_TYPE_STRING 7
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_INPUT_TYPE_STARTSTR 8
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_INPUT_TYPE_ENDSTR 9
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_OUTPUT_TYPE_STRING 10
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_OUTPUT_TYPE_STARTSTR 11
+#define SEL_GOOGLE_PROTOBUF_METHODDESCRIPTORPROTO_OUTPUT_TYPE_ENDSTR 12
+
+// google.protobuf.MethodOptions
+#define SEL_GOOGLE_PROTOBUF_METHODOPTIONS_UNINTERPRETED_OPTION_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_METHODOPTIONS_UNINTERPRETED_OPTION_STARTSEQ 3
+#define SEL_GOOGLE_PROTOBUF_METHODOPTIONS_UNINTERPRETED_OPTION_ENDSEQ 4
+#define SEL_GOOGLE_PROTOBUF_METHODOPTIONS_UNINTERPRETED_OPTION_ENDSUBMSG 5
+
+// google.protobuf.ServiceDescriptorProto
+#define SEL_GOOGLE_PROTOBUF_SERVICEDESCRIPTORPROTO_METHOD_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_SERVICEDESCRIPTORPROTO_OPTIONS_STARTSUBMSG 3
+#define SEL_GOOGLE_PROTOBUF_SERVICEDESCRIPTORPROTO_METHOD_STARTSEQ 4
+#define SEL_GOOGLE_PROTOBUF_SERVICEDESCRIPTORPROTO_METHOD_ENDSEQ 5
+#define SEL_GOOGLE_PROTOBUF_SERVICEDESCRIPTORPROTO_METHOD_ENDSUBMSG 6
+#define SEL_GOOGLE_PROTOBUF_SERVICEDESCRIPTORPROTO_OPTIONS_ENDSUBMSG 7
+#define SEL_GOOGLE_PROTOBUF_SERVICEDESCRIPTORPROTO_NAME_STRING 8
+#define SEL_GOOGLE_PROTOBUF_SERVICEDESCRIPTORPROTO_NAME_STARTSTR 9
+#define SEL_GOOGLE_PROTOBUF_SERVICEDESCRIPTORPROTO_NAME_ENDSTR 10
+
+// google.protobuf.ServiceOptions
+#define SEL_GOOGLE_PROTOBUF_SERVICEOPTIONS_UNINTERPRETED_OPTION_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_SERVICEOPTIONS_UNINTERPRETED_OPTION_STARTSEQ 3
+#define SEL_GOOGLE_PROTOBUF_SERVICEOPTIONS_UNINTERPRETED_OPTION_ENDSEQ 4
+#define SEL_GOOGLE_PROTOBUF_SERVICEOPTIONS_UNINTERPRETED_OPTION_ENDSUBMSG 5
+
+// google.protobuf.SourceCodeInfo
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_STARTSEQ 3
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_ENDSEQ 4
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_ENDSUBMSG 5
+
+// google.protobuf.SourceCodeInfo.Location
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_PATH_STARTSEQ 2
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_PATH_ENDSEQ 3
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_PATH_INT32 4
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_SPAN_STARTSEQ 5
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_SPAN_ENDSEQ 6
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_SPAN_INT32 7
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_LEADING_COMMENTS_STRING 8
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_LEADING_COMMENTS_STARTSTR 9
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_LEADING_COMMENTS_ENDSTR 10
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_TRAILING_COMMENTS_STRING 11
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_TRAILING_COMMENTS_STARTSTR 12
+#define SEL_GOOGLE_PROTOBUF_SOURCECODEINFO_LOCATION_TRAILING_COMMENTS_ENDSTR 13
+
+// google.protobuf.UninterpretedOption
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_NAME_STARTSUBMSG 2
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_NAME_STARTSEQ 3
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_NAME_ENDSEQ 4
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_NAME_ENDSUBMSG 5
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_IDENTIFIER_VALUE_STRING 6
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_IDENTIFIER_VALUE_STARTSTR 7
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_IDENTIFIER_VALUE_ENDSTR 8
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_POSITIVE_INT_VALUE_UINT64 9
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_NEGATIVE_INT_VALUE_INT64 10
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_DOUBLE_VALUE_DOUBLE 11
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_STRING_VALUE_STRING 12
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_STRING_VALUE_STARTSTR 13
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_STRING_VALUE_ENDSTR 14
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_AGGREGATE_VALUE_STRING 15
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_AGGREGATE_VALUE_STARTSTR 16
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_AGGREGATE_VALUE_ENDSTR 17
+
+// google.protobuf.UninterpretedOption.NamePart
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_NAMEPART_NAME_PART_STRING 2
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_NAMEPART_NAME_PART_STARTSTR 3
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_NAMEPART_NAME_PART_ENDSTR 4
+#define SEL_GOOGLE_PROTOBUF_UNINTERPRETEDOPTION_NAMEPART_IS_EXTENSION_BOOL 5
+
+const upb_symtab *upbdefs_google_protobuf_descriptor(const void *owner);
+
+// MessageDefs
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_DescriptorProto(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.DescriptorProto");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_DescriptorProto_ExtensionRange(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.DescriptorProto.ExtensionRange");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_EnumDescriptorProto(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.EnumDescriptorProto");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_EnumOptions(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.EnumOptions");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_EnumValueDescriptorProto(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.EnumValueDescriptorProto");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_EnumValueOptions(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.EnumValueOptions");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_FieldDescriptorProto(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.FieldDescriptorProto");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_FieldOptions(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.FieldOptions");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_FileDescriptorProto(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.FileDescriptorProto");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_FileDescriptorSet(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.FileDescriptorSet");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_FileOptions(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.FileOptions");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_MessageOptions(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.MessageOptions");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_MethodDescriptorProto(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.MethodDescriptorProto");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_MethodOptions(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.MethodOptions");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_ServiceDescriptorProto(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.ServiceDescriptorProto");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_ServiceOptions(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.ServiceOptions");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_SourceCodeInfo(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.SourceCodeInfo");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_SourceCodeInfo_Location(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.SourceCodeInfo.Location");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_UninterpretedOption(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.UninterpretedOption");
+  assert(m);
+  return m;
+}
+UPB_INLINE const upb_msgdef *upbdefs_google_protobuf_UninterpretedOption_NamePart(const upb_symtab *s) {
+  const upb_msgdef *m = upb_symtab_lookupmsg(s, "google.protobuf.UninterpretedOption.NamePart");
+  assert(m);
+  return m;
+}
+
+
+// EnumDefs
+UPB_INLINE const upb_enumdef *upbdefs_google_protobuf_FieldDescriptorProto_Label(const upb_symtab *s) {
+  const upb_enumdef *e = upb_symtab_lookupenum(s, "google.protobuf.FieldDescriptorProto.Label");
+  assert(e);
+  return e;
+}
+UPB_INLINE const upb_enumdef *upbdefs_google_protobuf_FieldDescriptorProto_Type(const upb_symtab *s) {
+  const upb_enumdef *e = upb_symtab_lookupenum(s, "google.protobuf.FieldDescriptorProto.Type");
+  assert(e);
+  return e;
+}
+UPB_INLINE const upb_enumdef *upbdefs_google_protobuf_FieldOptions_CType(const upb_symtab *s) {
+  const upb_enumdef *e = upb_symtab_lookupenum(s, "google.protobuf.FieldOptions.CType");
+  assert(e);
+  return e;
+}
+UPB_INLINE const upb_enumdef *upbdefs_google_protobuf_FileOptions_OptimizeMode(const upb_symtab *s) {
+  const upb_enumdef *e = upb_symtab_lookupenum(s, "google.protobuf.FileOptions.OptimizeMode");
+  assert(e);
+  return e;
+}
+
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_DescriptorProto_ExtensionRange_end(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_DescriptorProto_ExtensionRange(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_DescriptorProto_ExtensionRange_start(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_DescriptorProto_ExtensionRange(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_DescriptorProto_enum_type(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_DescriptorProto(s), 4); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_DescriptorProto_extension(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_DescriptorProto(s), 6); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_DescriptorProto_extension_range(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_DescriptorProto(s), 5); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_DescriptorProto_field(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_DescriptorProto(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_DescriptorProto_name(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_DescriptorProto(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_DescriptorProto_nested_type(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_DescriptorProto(s), 3); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_DescriptorProto_options(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_DescriptorProto(s), 7); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_EnumDescriptorProto_name(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_EnumDescriptorProto(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_EnumDescriptorProto_options(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_EnumDescriptorProto(s), 3); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_EnumDescriptorProto_value(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_EnumDescriptorProto(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_EnumOptions_allow_alias(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_EnumOptions(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_EnumOptions_uninterpreted_option(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_EnumOptions(s), 999); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_EnumValueDescriptorProto_name(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_EnumValueDescriptorProto(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_EnumValueDescriptorProto_number(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_EnumValueDescriptorProto(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_EnumValueDescriptorProto_options(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_EnumValueDescriptorProto(s), 3); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_EnumValueOptions_uninterpreted_option(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_EnumValueOptions(s), 999); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldDescriptorProto_default_value(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldDescriptorProto(s), 7); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldDescriptorProto_extendee(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldDescriptorProto(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldDescriptorProto_label(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldDescriptorProto(s), 4); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldDescriptorProto_name(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldDescriptorProto(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldDescriptorProto_number(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldDescriptorProto(s), 3); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldDescriptorProto_options(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldDescriptorProto(s), 8); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldDescriptorProto_type(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldDescriptorProto(s), 5); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldDescriptorProto_type_name(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldDescriptorProto(s), 6); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldOptions_ctype(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldOptions(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldOptions_deprecated(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldOptions(s), 3); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldOptions_experimental_map_key(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldOptions(s), 9); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldOptions_lazy(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldOptions(s), 5); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldOptions_packed(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldOptions(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldOptions_uninterpreted_option(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldOptions(s), 999); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FieldOptions_weak(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FieldOptions(s), 10); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_dependency(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 3); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_enum_type(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 5); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_extension(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 7); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_message_type(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 4); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_name(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_options(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 8); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_package(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_public_dependency(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 10); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_service(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 6); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_source_code_info(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 9); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorProto_weak_dependency(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorProto(s), 11); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileDescriptorSet_file(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileDescriptorSet(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileOptions_cc_generic_services(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileOptions(s), 16); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileOptions_go_package(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileOptions(s), 11); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileOptions_java_generate_equals_and_hash(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileOptions(s), 20); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileOptions_java_generic_services(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileOptions(s), 17); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileOptions_java_multiple_files(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileOptions(s), 10); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileOptions_java_outer_classname(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileOptions(s), 8); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileOptions_java_package(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileOptions(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileOptions_optimize_for(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileOptions(s), 9); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileOptions_py_generic_services(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileOptions(s), 18); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_FileOptions_uninterpreted_option(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_FileOptions(s), 999); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_MessageOptions_message_set_wire_format(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_MessageOptions(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_MessageOptions_no_standard_descriptor_accessor(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_MessageOptions(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_MessageOptions_uninterpreted_option(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_MessageOptions(s), 999); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_MethodDescriptorProto_input_type(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_MethodDescriptorProto(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_MethodDescriptorProto_name(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_MethodDescriptorProto(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_MethodDescriptorProto_options(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_MethodDescriptorProto(s), 4); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_MethodDescriptorProto_output_type(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_MethodDescriptorProto(s), 3); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_MethodOptions_uninterpreted_option(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_MethodOptions(s), 999); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_ServiceDescriptorProto_method(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_ServiceDescriptorProto(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_ServiceDescriptorProto_name(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_ServiceDescriptorProto(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_ServiceDescriptorProto_options(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_ServiceDescriptorProto(s), 3); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_ServiceOptions_uninterpreted_option(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_ServiceOptions(s), 999); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_SourceCodeInfo_Location_leading_comments(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_SourceCodeInfo_Location(s), 3); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_SourceCodeInfo_Location_path(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_SourceCodeInfo_Location(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_SourceCodeInfo_Location_span(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_SourceCodeInfo_Location(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_SourceCodeInfo_Location_trailing_comments(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_SourceCodeInfo_Location(s), 4); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_SourceCodeInfo_location(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_SourceCodeInfo(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_UninterpretedOption_NamePart_is_extension(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_UninterpretedOption_NamePart(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_UninterpretedOption_NamePart_name_part(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_UninterpretedOption_NamePart(s), 1); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_UninterpretedOption_aggregate_value(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_UninterpretedOption(s), 8); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_UninterpretedOption_double_value(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_UninterpretedOption(s), 6); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_UninterpretedOption_identifier_value(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_UninterpretedOption(s), 3); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_UninterpretedOption_name(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_UninterpretedOption(s), 2); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_UninterpretedOption_negative_int_value(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_UninterpretedOption(s), 5); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_UninterpretedOption_positive_int_value(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_UninterpretedOption(s), 4); }
+UPB_INLINE const upb_fielddef *upbdefs_google_protobuf_UninterpretedOption_string_value(const upb_symtab *s) { return upb_msgdef_itof(upbdefs_google_protobuf_UninterpretedOption(s), 7); }
+
+#ifdef __cplusplus
+};  // extern "C"
+#endif
+
+#ifdef __cplusplus
+
+namespace upbdefs {
+namespace google {
+namespace protobuf {
+namespace descriptor {
+inline upb::reffed_ptr<const upb::SymbolTable> SymbolTable() {
+  const upb::SymbolTable* s = upbdefs_google_protobuf_descriptor(&s);
+  return upb::reffed_ptr<const upb::SymbolTable>(s, &s);
+}
+}  // namespace descriptor
+}  // namespace protobuf
+}  // namespace google
+
+#define RETURN_REFFED(type, func) \
+    const type* obj = func(upbdefs::google::protobuf::descriptor::SymbolTable().get()); \
+    return upb::reffed_ptr<const type>(obj);
+
+namespace google {
+namespace protobuf {
+namespace DescriptorProto {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_DescriptorProto) }
+inline upb::reffed_ptr<const upb::FieldDef> enum_type() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_DescriptorProto_enum_type) }
+inline upb::reffed_ptr<const upb::FieldDef> extension() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_DescriptorProto_extension) }
+inline upb::reffed_ptr<const upb::FieldDef> extension_range() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_DescriptorProto_extension_range) }
+inline upb::reffed_ptr<const upb::FieldDef> field() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_DescriptorProto_field) }
+inline upb::reffed_ptr<const upb::FieldDef> name() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_DescriptorProto_name) }
+inline upb::reffed_ptr<const upb::FieldDef> nested_type() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_DescriptorProto_nested_type) }
+inline upb::reffed_ptr<const upb::FieldDef> options() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_DescriptorProto_options) }
+}  // namespace DescriptorProto
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace DescriptorProto {
+namespace ExtensionRange {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_DescriptorProto_ExtensionRange) }
+inline upb::reffed_ptr<const upb::FieldDef> end() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_DescriptorProto_ExtensionRange_end) }
+inline upb::reffed_ptr<const upb::FieldDef> start() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_DescriptorProto_ExtensionRange_start) }
+}  // namespace ExtensionRange
+}  // namespace DescriptorProto
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace EnumDescriptorProto {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_EnumDescriptorProto) }
+inline upb::reffed_ptr<const upb::FieldDef> name() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_EnumDescriptorProto_name) }
+inline upb::reffed_ptr<const upb::FieldDef> options() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_EnumDescriptorProto_options) }
+inline upb::reffed_ptr<const upb::FieldDef> value() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_EnumDescriptorProto_value) }
+}  // namespace EnumDescriptorProto
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace EnumOptions {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_EnumOptions) }
+inline upb::reffed_ptr<const upb::FieldDef> allow_alias() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_EnumOptions_allow_alias) }
+inline upb::reffed_ptr<const upb::FieldDef> uninterpreted_option() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_EnumOptions_uninterpreted_option) }
+}  // namespace EnumOptions
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace EnumValueDescriptorProto {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_EnumValueDescriptorProto) }
+inline upb::reffed_ptr<const upb::FieldDef> name() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_EnumValueDescriptorProto_name) }
+inline upb::reffed_ptr<const upb::FieldDef> number() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_EnumValueDescriptorProto_number) }
+inline upb::reffed_ptr<const upb::FieldDef> options() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_EnumValueDescriptorProto_options) }
+}  // namespace EnumValueDescriptorProto
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace EnumValueOptions {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_EnumValueOptions) }
+inline upb::reffed_ptr<const upb::FieldDef> uninterpreted_option() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_EnumValueOptions_uninterpreted_option) }
+}  // namespace EnumValueOptions
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace FieldDescriptorProto {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_FieldDescriptorProto) }
+inline upb::reffed_ptr<const upb::FieldDef> default_value() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldDescriptorProto_default_value) }
+inline upb::reffed_ptr<const upb::FieldDef> extendee() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldDescriptorProto_extendee) }
+inline upb::reffed_ptr<const upb::FieldDef> label() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldDescriptorProto_label) }
+inline upb::reffed_ptr<const upb::FieldDef> name() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldDescriptorProto_name) }
+inline upb::reffed_ptr<const upb::FieldDef> number() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldDescriptorProto_number) }
+inline upb::reffed_ptr<const upb::FieldDef> options() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldDescriptorProto_options) }
+inline upb::reffed_ptr<const upb::FieldDef> type() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldDescriptorProto_type) }
+inline upb::reffed_ptr<const upb::FieldDef> type_name() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldDescriptorProto_type_name) }
+inline upb::reffed_ptr<const upb::EnumDef> Label() { RETURN_REFFED(upb::EnumDef, upbdefs_google_protobuf_FieldDescriptorProto_Label) }
+inline upb::reffed_ptr<const upb::EnumDef> Type() { RETURN_REFFED(upb::EnumDef, upbdefs_google_protobuf_FieldDescriptorProto_Type) }
+}  // namespace FieldDescriptorProto
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace FieldOptions {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_FieldOptions) }
+inline upb::reffed_ptr<const upb::FieldDef> ctype() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldOptions_ctype) }
+inline upb::reffed_ptr<const upb::FieldDef> deprecated() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldOptions_deprecated) }
+inline upb::reffed_ptr<const upb::FieldDef> experimental_map_key() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldOptions_experimental_map_key) }
+inline upb::reffed_ptr<const upb::FieldDef> lazy() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldOptions_lazy) }
+inline upb::reffed_ptr<const upb::FieldDef> packed() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldOptions_packed) }
+inline upb::reffed_ptr<const upb::FieldDef> uninterpreted_option() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldOptions_uninterpreted_option) }
+inline upb::reffed_ptr<const upb::FieldDef> weak() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FieldOptions_weak) }
+inline upb::reffed_ptr<const upb::EnumDef> CType() { RETURN_REFFED(upb::EnumDef, upbdefs_google_protobuf_FieldOptions_CType) }
+}  // namespace FieldOptions
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace FileDescriptorProto {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_FileDescriptorProto) }
+inline upb::reffed_ptr<const upb::FieldDef> dependency() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_dependency) }
+inline upb::reffed_ptr<const upb::FieldDef> enum_type() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_enum_type) }
+inline upb::reffed_ptr<const upb::FieldDef> extension() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_extension) }
+inline upb::reffed_ptr<const upb::FieldDef> message_type() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_message_type) }
+inline upb::reffed_ptr<const upb::FieldDef> name() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_name) }
+inline upb::reffed_ptr<const upb::FieldDef> options() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_options) }
+inline upb::reffed_ptr<const upb::FieldDef> package() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_package) }
+inline upb::reffed_ptr<const upb::FieldDef> public_dependency() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_public_dependency) }
+inline upb::reffed_ptr<const upb::FieldDef> service() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_service) }
+inline upb::reffed_ptr<const upb::FieldDef> source_code_info() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_source_code_info) }
+inline upb::reffed_ptr<const upb::FieldDef> weak_dependency() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorProto_weak_dependency) }
+}  // namespace FileDescriptorProto
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace FileDescriptorSet {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_FileDescriptorSet) }
+inline upb::reffed_ptr<const upb::FieldDef> file() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileDescriptorSet_file) }
+}  // namespace FileDescriptorSet
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace FileOptions {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_FileOptions) }
+inline upb::reffed_ptr<const upb::FieldDef> cc_generic_services() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileOptions_cc_generic_services) }
+inline upb::reffed_ptr<const upb::FieldDef> go_package() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileOptions_go_package) }
+inline upb::reffed_ptr<const upb::FieldDef> java_generate_equals_and_hash() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileOptions_java_generate_equals_and_hash) }
+inline upb::reffed_ptr<const upb::FieldDef> java_generic_services() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileOptions_java_generic_services) }
+inline upb::reffed_ptr<const upb::FieldDef> java_multiple_files() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileOptions_java_multiple_files) }
+inline upb::reffed_ptr<const upb::FieldDef> java_outer_classname() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileOptions_java_outer_classname) }
+inline upb::reffed_ptr<const upb::FieldDef> java_package() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileOptions_java_package) }
+inline upb::reffed_ptr<const upb::FieldDef> optimize_for() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileOptions_optimize_for) }
+inline upb::reffed_ptr<const upb::FieldDef> py_generic_services() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileOptions_py_generic_services) }
+inline upb::reffed_ptr<const upb::FieldDef> uninterpreted_option() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_FileOptions_uninterpreted_option) }
+inline upb::reffed_ptr<const upb::EnumDef> OptimizeMode() { RETURN_REFFED(upb::EnumDef, upbdefs_google_protobuf_FileOptions_OptimizeMode) }
+}  // namespace FileOptions
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace MessageOptions {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_MessageOptions) }
+inline upb::reffed_ptr<const upb::FieldDef> message_set_wire_format() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_MessageOptions_message_set_wire_format) }
+inline upb::reffed_ptr<const upb::FieldDef> no_standard_descriptor_accessor() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_MessageOptions_no_standard_descriptor_accessor) }
+inline upb::reffed_ptr<const upb::FieldDef> uninterpreted_option() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_MessageOptions_uninterpreted_option) }
+}  // namespace MessageOptions
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace MethodDescriptorProto {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_MethodDescriptorProto) }
+inline upb::reffed_ptr<const upb::FieldDef> input_type() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_MethodDescriptorProto_input_type) }
+inline upb::reffed_ptr<const upb::FieldDef> name() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_MethodDescriptorProto_name) }
+inline upb::reffed_ptr<const upb::FieldDef> options() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_MethodDescriptorProto_options) }
+inline upb::reffed_ptr<const upb::FieldDef> output_type() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_MethodDescriptorProto_output_type) }
+}  // namespace MethodDescriptorProto
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace MethodOptions {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_MethodOptions) }
+inline upb::reffed_ptr<const upb::FieldDef> uninterpreted_option() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_MethodOptions_uninterpreted_option) }
+}  // namespace MethodOptions
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace ServiceDescriptorProto {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_ServiceDescriptorProto) }
+inline upb::reffed_ptr<const upb::FieldDef> method() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_ServiceDescriptorProto_method) }
+inline upb::reffed_ptr<const upb::FieldDef> name() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_ServiceDescriptorProto_name) }
+inline upb::reffed_ptr<const upb::FieldDef> options() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_ServiceDescriptorProto_options) }
+}  // namespace ServiceDescriptorProto
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace ServiceOptions {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_ServiceOptions) }
+inline upb::reffed_ptr<const upb::FieldDef> uninterpreted_option() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_ServiceOptions_uninterpreted_option) }
+}  // namespace ServiceOptions
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace SourceCodeInfo {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_SourceCodeInfo) }
+inline upb::reffed_ptr<const upb::FieldDef> location() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_SourceCodeInfo_location) }
+}  // namespace SourceCodeInfo
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace SourceCodeInfo {
+namespace Location {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_SourceCodeInfo_Location) }
+inline upb::reffed_ptr<const upb::FieldDef> leading_comments() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_SourceCodeInfo_Location_leading_comments) }
+inline upb::reffed_ptr<const upb::FieldDef> path() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_SourceCodeInfo_Location_path) }
+inline upb::reffed_ptr<const upb::FieldDef> span() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_SourceCodeInfo_Location_span) }
+inline upb::reffed_ptr<const upb::FieldDef> trailing_comments() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_SourceCodeInfo_Location_trailing_comments) }
+}  // namespace Location
+}  // namespace SourceCodeInfo
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace UninterpretedOption {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_UninterpretedOption) }
+inline upb::reffed_ptr<const upb::FieldDef> aggregate_value() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_UninterpretedOption_aggregate_value) }
+inline upb::reffed_ptr<const upb::FieldDef> double_value() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_UninterpretedOption_double_value) }
+inline upb::reffed_ptr<const upb::FieldDef> identifier_value() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_UninterpretedOption_identifier_value) }
+inline upb::reffed_ptr<const upb::FieldDef> name() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_UninterpretedOption_name) }
+inline upb::reffed_ptr<const upb::FieldDef> negative_int_value() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_UninterpretedOption_negative_int_value) }
+inline upb::reffed_ptr<const upb::FieldDef> positive_int_value() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_UninterpretedOption_positive_int_value) }
+inline upb::reffed_ptr<const upb::FieldDef> string_value() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_UninterpretedOption_string_value) }
+}  // namespace UninterpretedOption
+}  // namespace protobuf
+}  // namespace google
+
+namespace google {
+namespace protobuf {
+namespace UninterpretedOption {
+namespace NamePart {
+inline upb::reffed_ptr<const upb::MessageDef> MessageDef() { RETURN_REFFED(upb::MessageDef, upbdefs_google_protobuf_UninterpretedOption_NamePart) }
+inline upb::reffed_ptr<const upb::FieldDef> is_extension() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_UninterpretedOption_NamePart_is_extension) }
+inline upb::reffed_ptr<const upb::FieldDef> name_part() { RETURN_REFFED(upb::FieldDef, upbdefs_google_protobuf_UninterpretedOption_NamePart_name_part) }
+}  // namespace NamePart
+}  // namespace UninterpretedOption
+}  // namespace protobuf
+}  // namespace google
+
+}  // namespace upbdefs
+
+
+#undef RETURN_REFFED
+#endif // __cplusplus
+
+#endif  // GOOGLE_PROTOBUF_DESCRIPTOR_UPB_H_
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2010-2012 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * A upb_handlers is like a virtual table for a upb_msgdef.  Each field of the
+ * message can have associated functions that will be called when we are
+ * parsing or visiting a stream of data.  This is similar to how handlers work
+ * in SAX (the Simple API for XML).
+ *
+ * The handlers have no idea where the data is coming from, so a single set of
+ * handlers could be used with two completely different data sources (for
+ * example, a parser and a visitor over in-memory objects).  This decoupling is
+ * the most important feature of upb, because it allows parsers and serializers
+ * to be highly reusable.
+ *
+ * This is a mixed C/C++ interface that offers a full API to both languages.
+ * See the top-level README for more information.
+ */
+
+#ifndef UPB_HANDLERS_H
+#define UPB_HANDLERS_H
+
+
+#ifdef __cplusplus
+namespace upb {
+class BufferHandle;
+class BytesHandler;
+class HandlerAttributes;
+class Handlers;
+template <class T> class Handler;
+template <class T> struct CanonicalType;
+}  // namespace upb
+#endif
+
+UPB_DECLARE_TYPE(upb::BufferHandle, upb_bufhandle);
+UPB_DECLARE_TYPE(upb::BytesHandler, upb_byteshandler);
+UPB_DECLARE_TYPE(upb::HandlerAttributes, upb_handlerattr);
+UPB_DECLARE_TYPE(upb::Handlers, upb_handlers);
+
+// The maximum depth that the handler graph can have.  This is a resource limit
+// for the C stack since we sometimes need to recursively traverse the graph.
+// Cycles are ok; the traversal will stop when it detects a cycle, but we must
+// hit the cycle before the maximum depth is reached.
+//
+// If having a single static limit is too inflexible, we can add another variant
+// of Handlers::Freeze that allows specifying this as a parameter.
+#define UPB_MAX_HANDLER_DEPTH 64
+
+// All the different types of handlers that can be registered.
+// Only needed for the advanced functions in upb::Handlers.
+typedef enum {
+  UPB_HANDLER_INT32,
+  UPB_HANDLER_INT64,
+  UPB_HANDLER_UINT32,
+  UPB_HANDLER_UINT64,
+  UPB_HANDLER_FLOAT,
+  UPB_HANDLER_DOUBLE,
+  UPB_HANDLER_BOOL,
+  UPB_HANDLER_STARTSTR,
+  UPB_HANDLER_STRING,
+  UPB_HANDLER_ENDSTR,
+  UPB_HANDLER_STARTSUBMSG,
+  UPB_HANDLER_ENDSUBMSG,
+  UPB_HANDLER_STARTSEQ,
+  UPB_HANDLER_ENDSEQ,
+} upb_handlertype_t;
+
+#define UPB_HANDLER_MAX (UPB_HANDLER_ENDSEQ+1)
+
+#define UPB_BREAK NULL
+
+// A convenient definition for when no closure is needed.
+extern char _upb_noclosure;
+#define UPB_NO_CLOSURE &_upb_noclosure
+
+// A selector refers to a specific field handler in the Handlers object
+// (for example: the STARTSUBMSG handler for field "field15").
+typedef int32_t upb_selector_t;
+
+UPB_BEGIN_EXTERN_C
+
+// Forward-declares for C inline accessors.  We need to declare these here
+// so we can "friend" them in the class declarations in C++.
+UPB_INLINE upb_func *upb_handlers_gethandler(const upb_handlers *h,
+                                             upb_selector_t s);
+UPB_INLINE const void *upb_handlerattr_handlerdata(const upb_handlerattr *attr);
+UPB_INLINE const void *upb_handlers_gethandlerdata(const upb_handlers *h,
+                                                   upb_selector_t s);
+
+UPB_INLINE void upb_bufhandle_init(upb_bufhandle *h);
+UPB_INLINE void upb_bufhandle_setobj(upb_bufhandle *h, const void *obj,
+                                     const void *type);
+UPB_INLINE void upb_bufhandle_setbuf(upb_bufhandle *h, const char *buf,
+                                     size_t ofs);
+UPB_INLINE const void *upb_bufhandle_obj(const upb_bufhandle *h);
+UPB_INLINE const void *upb_bufhandle_objtype(const upb_bufhandle *h);
+UPB_INLINE const char *upb_bufhandle_buf(const upb_bufhandle *h);
+
+UPB_END_EXTERN_C
+
+
+// Static selectors for upb::Handlers.
+#define UPB_STARTMSG_SELECTOR 0
+#define UPB_ENDMSG_SELECTOR 1
+#define UPB_STATIC_SELECTOR_COUNT 2
+
+// Static selectors for upb::BytesHandler.
+#define UPB_STARTSTR_SELECTOR 0
+#define UPB_STRING_SELECTOR 1
+#define UPB_ENDSTR_SELECTOR 2
+
+typedef void upb_handlerfree(void *d);
+
+// A set of attributes that accompanies a handler's function pointer.
+UPB_DEFINE_CLASS0(upb::HandlerAttributes,
+ public:
+  HandlerAttributes();
+  ~HandlerAttributes();
+
+  // Sets the handler data that will be passed as the second parameter of the
+  // handler.  To free this pointer when the handlers are freed, call
+  // Handlers::AddCleanup().
+  bool SetHandlerData(const void *handler_data);
+  const void* handler_data() const;
+
+  // Use this to specify the type of the closure.  This will be checked against
+  // all other closure types for handler that use the same closure.
+  // Registration will fail if this does not match all other non-NULL closure
+  // types.
+  bool SetClosureType(const void *closure_type);
+  const void* closure_type() const;
+
+  // Use this to specify the type of the returned closure.  Only used for
+  // Start*{String,SubMessage,Sequence} handlers.  This must match the closure
+  // type of any handlers that use it (for example, the StringBuf handler must
+  // match the closure returned from StartString).
+  bool SetReturnClosureType(const void *return_closure_type);
+  const void* return_closure_type() const;
+
+  // Set to indicate that the handler always returns "ok" (either "true" or a
+  // non-NULL closure).  This is a hint that can allow code generators to
+  // generate more efficient code.
+  bool SetAlwaysOk(bool always_ok);
+  bool always_ok() const;
+
+ private:
+  friend UPB_INLINE const void * ::upb_handlerattr_handlerdata(
+      const upb_handlerattr *attr);
+,
+UPB_DEFINE_STRUCT0(upb_handlerattr,
+  const void *handler_data_;
+  const void *closure_type_;
+  const void *return_closure_type_;
+  bool alwaysok_;
+));
+
+#define UPB_HANDLERATTR_INITIALIZER {NULL, NULL, NULL, false}
+
+typedef struct {
+  upb_func *func;
+  // It is wasteful to include the entire attributes here:
+  //
+  // * Some of the information is redundant (like storing the closure type
+  //   separately for each handler that must match).
+  // * Some of the info is only needed prior to freeze() (like closure types).
+  // * alignment padding wastes a lot of space for alwaysok_.
+  //
+  // If/when the size and locality of handlers is an issue, we can optimize this
+  // not to store the entire attr like this.  We do not expose the table's
+  // layout to allow this optimization in the future.
+  upb_handlerattr attr;
+} upb_handlers_tabent;
+
+// Extra information about a buffer that is passed to a StringBuf handler.
+// TODO(haberman): allow the handle to be pinned so that it will outlive
+// the handler invocation.
+UPB_DEFINE_CLASS0(upb::BufferHandle,
+ public:
+  BufferHandle();
+  ~BufferHandle();
+
+  // The beginning of the buffer.  This may be different than the pointer
+  // passed to a StringBuf handler because the handler may receive data
+  // that is from the middle or end of a larger buffer.
+  const char* buffer() const;
+
+  // The offset within the attached object where this buffer begins.  Only
+  // meaningful if there is an attached object.
+  size_t object_offset() const;
+
+  // Note that object_offset is the offset of "buf" within the attached object.
+  void SetBuffer(const char* buf, size_t object_offset);
+
+  // The BufferHandle can have an "attached object", which can be used to
+  // tunnel through a pointer to the buffer's underlying representation.
+  template <class T>
+  void SetAttachedObject(const T* obj);
+
+  // Returns NULL if the attached object is not of this type.
+  template <class T>
+  const T* GetAttachedObject() const;
+
+ private:
+  friend UPB_INLINE void ::upb_bufhandle_init(upb_bufhandle *h);
+  friend UPB_INLINE void ::upb_bufhandle_setobj(upb_bufhandle *h,
+                                                const void *obj,
+                                                const void *type);
+  friend UPB_INLINE void ::upb_bufhandle_setbuf(upb_bufhandle *h,
+                                                const char *buf, size_t ofs);
+  friend UPB_INLINE const void* ::upb_bufhandle_obj(const upb_bufhandle *h);
+  friend UPB_INLINE const void* ::upb_bufhandle_objtype(
+      const upb_bufhandle *h);
+  friend UPB_INLINE const char* ::upb_bufhandle_buf(const upb_bufhandle *h);
+,
+UPB_DEFINE_STRUCT0(upb_bufhandle,
+  const char *buf_;
+  const void *obj_;
+  const void *objtype_;
+  size_t objofs_;
+));
+
+// A upb::Handlers object represents the set of handlers associated with a
+// message in the graph of messages.  You can think of it as a big virtual
+// table with functions corresponding to all the events that can fire while
+// parsing or visiting a message of a specific type.
+//
+// Any handlers that are not set behave as if they had successfully consumed
+// the value.  Any unset Start* handlers will propagate their closure to the
+// inner frame.
+//
+// The easiest way to create the *Handler objects needed by the Set* methods is
+// with the UpbBind() and UpbMakeHandler() macros; see below.
+UPB_DEFINE_CLASS1(upb::Handlers, upb::RefCounted,
+ public:
+  typedef upb_selector_t Selector;
+  typedef upb_handlertype_t Type;
+
+  typedef Handler<void *(*)(void *, const void *)> StartFieldHandler;
+  typedef Handler<bool (*)(void *, const void *)> EndFieldHandler;
+  typedef Handler<bool (*)(void *, const void *)> StartMessageHandler;
+  typedef Handler<bool (*)(void *, const void *, Status*)> EndMessageHandler;
+  typedef Handler<void *(*)(void *, const void *, size_t)> StartStringHandler;
+  typedef Handler<size_t (*)(void *, const void *, const char *, size_t,
+                             const BufferHandle *)> StringHandler;
+
+  template <class T> struct ValueHandler {
+    typedef Handler<bool(*)(void *, const void *, T)> H;
+  };
+
+  typedef ValueHandler<int32_t>::H     Int32Handler;
+  typedef ValueHandler<int64_t>::H     Int64Handler;
+  typedef ValueHandler<uint32_t>::H    UInt32Handler;
+  typedef ValueHandler<uint64_t>::H    UInt64Handler;
+  typedef ValueHandler<float>::H       FloatHandler;
+  typedef ValueHandler<double>::H      DoubleHandler;
+  typedef ValueHandler<bool>::H        BoolHandler;
+
+  // Any function pointer can be converted to this and converted back to its
+  // correct type.
+  typedef void GenericFunction();
+
+  typedef void HandlersCallback(const void *closure, upb_handlers *h);
+
+  // Returns a new handlers object for the given frozen msgdef.
+  // Returns NULL if memory allocation failed.
+  static reffed_ptr<Handlers> New(const MessageDef *m);
+
+  // Convenience function for registering a graph of handlers that mirrors the
+  // graph of msgdefs for some message.  For "m" and all its children a new set
+  // of handlers will be created and the given callback will be invoked,
+  // allowing the client to register handlers for this message.  Note that any
+  // subhandlers set by the callback will be overwritten.
+  static reffed_ptr<const Handlers> NewFrozen(const MessageDef *m,
+                                              HandlersCallback *callback,
+                                              const void *closure);
+
+  // Functionality from upb::RefCounted.
+  bool IsFrozen() const;
+  void Ref(const void* owner) const;
+  void Unref(const void* owner) const;
+  void DonateRef(const void *from, const void *to) const;
+  void CheckRef(const void *owner) const;
+
+  // All handler registration functions return bool to indicate success or
+  // failure; details about failures are stored in this status object.  If a
+  // failure does occur, it must be cleared before the Handlers are frozen,
+  // otherwise the freeze() operation will fail.  The functions may *only* be
+  // used while the Handlers are mutable.
+  const Status* status();
+  void ClearError();
+
+  // Call to freeze these Handlers.  Requires that any SubHandlers are already
+  // frozen.  For cycles, you must use the static version below and freeze the
+  // whole graph at once.
+  bool Freeze(Status* s);
+
+  // Freezes the given set of handlers.  You may not freeze a handler without
+  // also freezing any handlers they point to.
+  static bool Freeze(Handlers*const* handlers, int n, Status* s);
+  static bool Freeze(const std::vector<Handlers*>& handlers, Status* s);
+
+  // Returns the msgdef associated with this handlers object.
+  const MessageDef* message_def() const;
+
+  // Adds the given pointer and function to the list of cleanup functions that
+  // will be run when these handlers are freed.  If this pointer has previously
+  // been registered, the function returns false and does nothing.
+  bool AddCleanup(void *ptr, upb_handlerfree *cleanup);
+
+  // Sets the startmsg handler for the message, which is defined as follows:
+  //
+  //   bool startmsg(MyType* closure) {
+  //     // Called when the message begins.  Returns true if processing should
+  //     // continue.
+  //     return true;
+  //   }
+  bool SetStartMessageHandler(const StartMessageHandler& handler);
+
+  // Sets the endmsg handler for the message, which is defined as follows:
+  //
+  //   bool endmsg(MyType* closure, upb_status *status) {
+  //     // Called when processing of this message ends, whether in success or
+  //     // failure.  "status" indicates the final status of processing, and
+  //     // can also be modified in-place to update the final status.
+  //   }
+  bool SetEndMessageHandler(const EndMessageHandler& handler);
+
+  // Sets the value handler for the given field, which is defined as follows
+  // (this is for an int32 field; other field types will pass their native
+  // C/C++ type for "val"):
+  //
+  //   bool OnValue(MyClosure* c, const MyHandlerData* d, int32_t val) {
+  //     // Called when the field's value is encountered.  "d" contains
+  //     // whatever data was bound to this field when it was registered.
+  //     // Returns true if processing should continue.
+  //     return true;
+  //   }
+  //
+  //   handers->SetInt32Handler(f, UpbBind(OnValue, new MyHandlerData(...)));
+  //
+  // The value type must exactly match f->type().
+  // For example, a handler that takes an int32_t parameter may only be used for
+  // fields of type UPB_TYPE_INT32 and UPB_TYPE_ENUM.
+  //
+  // Returns false if the handler failed to register; in this case the cleanup
+  // handler (if any) will be called immediately.
+  bool SetInt32Handler (const FieldDef* f,  const Int32Handler& h);
+  bool SetInt64Handler (const FieldDef* f,  const Int64Handler& h);
+  bool SetUInt32Handler(const FieldDef* f, const UInt32Handler& h);
+  bool SetUInt64Handler(const FieldDef* f, const UInt64Handler& h);
+  bool SetFloatHandler (const FieldDef* f,  const FloatHandler& h);
+  bool SetDoubleHandler(const FieldDef* f, const DoubleHandler& h);
+  bool SetBoolHandler  (const FieldDef* f,   const BoolHandler& h);
+
+  // Like the previous, but templated on the type on the value (ie. int32).
+  // This is mostly useful to call from other templates.  To call this you must
+  // specify the template parameter explicitly, ie:
+  //   h->SetValueHandler<T>(f, UpbBind(MyHandler<T>, MyData));
+  template <class T>
+  bool SetValueHandler(
+      const FieldDef *f,
+      const typename ValueHandler<typename CanonicalType<T>::Type>::H& handler);
+
+  // Sets handlers for a string field, which are defined as follows:
+  //
+  //   MySubClosure* startstr(MyClosure* c, const MyHandlerData* d,
+  //                          size_t size_hint) {
+  //     // Called when a string value begins.  The return value indicates the
+  //     // closure for the string.  "size_hint" indicates the size of the
+  //     // string if it is known, however if the string is length-delimited
+  //     // and the end-of-string is not available size_hint will be zero.
+  //     // This case is indistinguishable from the case where the size is
+  //     // known to be zero.
+  //     //
+  //     // TODO(haberman): is it important to distinguish these cases?
+  //     // If we had ssize_t as a type we could make -1 "unknown", but
+  //     // ssize_t is POSIX (not ANSI) and therefore less portable.
+  //     // In practice I suspect it won't be important to distinguish.
+  //     return closure;
+  //   }
+  //
+  //   size_t str(MyClosure* closure, const MyHandlerData* d,
+  //              const char *str, size_t len) {
+  //     // Called for each buffer of string data; the multiple physical buffers
+  //     // are all part of the same logical string.  The return value indicates
+  //     // how many bytes were consumed.  If this number is less than "len",
+  //     // this will also indicate that processing should be halted for now,
+  //     // like returning false or UPB_BREAK from any other callback.  If
+  //     // number is greater than "len", the excess bytes will be skipped over
+  //     // and not passed to the callback.
+  //     return len;
+  //   }
+  //
+  //   bool endstr(MyClosure* c, const MyHandlerData* d) {
+  //     // Called when a string value ends.  Return value indicates whether
+  //     // processing should continue.
+  //     return true;
+  //   }
+  bool SetStartStringHandler(const FieldDef* f, const StartStringHandler& h);
+  bool SetStringHandler(const FieldDef* f, const StringHandler& h);
+  bool SetEndStringHandler(const FieldDef* f, const EndFieldHandler& h);
+
+  // Sets the startseq handler, which is defined as follows:
+  //
+  //   MySubClosure *startseq(MyClosure* c, const MyHandlerData* d) {
+  //     // Called when a sequence (repeated field) begins.  The returned
+  //     // pointer indicates the closure for the sequence (or UPB_BREAK
+  //     // to interrupt processing).
+  //     return closure;
+  //   }
+  //
+  //   h->SetStartSequenceHandler(f, UpbBind(startseq, new MyHandlerData(...)));
+  //
+  // Returns "false" if "f" does not belong to this message or is not a
+  // repeated field.
+  bool SetStartSequenceHandler(const FieldDef* f, const StartFieldHandler& h);
+
+  // Sets the startsubmsg handler for the given field, which is defined as
+  // follows:
+  //
+  //   MySubClosure* startsubmsg(MyClosure* c, const MyHandlerData* d) {
+  //     // Called when a submessage begins.  The returned pointer indicates the
+  //     // closure for the sequence (or UPB_BREAK to interrupt processing).
+  //     return closure;
+  //   }
+  //
+  //   h->SetStartSubMessageHandler(f, UpbBind(startsubmsg,
+  //                                           new MyHandlerData(...)));
+  //
+  // Returns "false" if "f" does not belong to this message or is not a
+  // submessage/group field.
+  bool SetStartSubMessageHandler(const FieldDef* f, const StartFieldHandler& h);
+
+  // Sets the endsubmsg handler for the given field, which is defined as
+  // follows:
+  //
+  //   bool endsubmsg(MyClosure* c, const MyHandlerData* d) {
+  //     // Called when a submessage ends.  Returns true to continue processing.
+  //     return true;
+  //   }
+  //
+  // Returns "false" if "f" does not belong to this message or is not a
+  // submessage/group field.
+  bool SetEndSubMessageHandler(const FieldDef *f, const EndFieldHandler &h);
+
+  // Starts the endsubseq handler for the given field, which is defined as
+  // follows:
+  //
+  //   bool endseq(MyClosure* c, const MyHandlerData* d) {
+  //     // Called when a sequence ends.  Returns true continue processing.
+  //     return true;
+  //   }
+  //
+  // Returns "false" if "f" does not belong to this message or is not a
+  // repeated field.
+  bool SetEndSequenceHandler(const FieldDef* f, const EndFieldHandler& h);
+
+  // Sets or gets the object that specifies handlers for the given field, which
+  // must be a submessage or group.  Returns NULL if no handlers are set.
+  bool SetSubHandlers(const FieldDef* f, const Handlers* sub);
+  const Handlers* GetSubHandlers(const FieldDef* f) const;
+
+  // Equivalent to GetSubHandlers, but takes the STARTSUBMSG selector for the
+  // field.
+  const Handlers* GetSubHandlers(Selector startsubmsg) const;
+
+  // A selector refers to a specific field handler in the Handlers object
+  // (for example: the STARTSUBMSG handler for field "field15").
+  // On success, returns true and stores the selector in "s".
+  // If the FieldDef or Type are invalid, returns false.
+  // The returned selector is ONLY valid for Handlers whose MessageDef
+  // contains this FieldDef.
+  static bool GetSelector(const FieldDef* f, Type type, Selector* s);
+
+  // Given a START selector of any kind, returns the corresponding END selector.
+  static Selector GetEndSelector(Selector start_selector);
+
+  // Returns the function pointer for this handler.  It is the client's
+  // responsibility to cast to the correct function type before calling it.
+  GenericFunction* GetHandler(Selector selector);
+
+  // Sets the given attributes to the attributes for this selector.
+  bool GetAttributes(Selector selector, HandlerAttributes* attr);
+
+  // Returns the handler data that was registered with this handler.
+  const void* GetHandlerData(Selector selector);
+
+  // Could add any of the following functions as-needed, with some minor
+  // implementation changes:
+  //
+  // const FieldDef* GetFieldDef(Selector selector);
+  // static bool IsSequence(Selector selector);
+
+ private:
+  UPB_DISALLOW_POD_OPS(Handlers, upb::Handlers);
+
+  friend UPB_INLINE GenericFunction *::upb_handlers_gethandler(
+      const upb_handlers *h, upb_selector_t s);
+  friend UPB_INLINE const void *::upb_handlers_gethandlerdata(
+      const upb_handlers *h, upb_selector_t s);
+
+,
+UPB_DEFINE_STRUCT(upb_handlers, upb_refcounted,
+  const upb_msgdef *msg;
+  const upb_handlers **sub;
+  const void *top_closure_type;
+  upb_inttable cleanup_;
+  upb_status status_;  // Used only when mutable.
+  upb_handlers_tabent table[1];  // Dynamically-sized field handler array.
+));
+
+
+#ifdef __cplusplus
+
+namespace upb {
+
+// Convenience macros for creating a Handler object that is wrapped with a
+// type-safe wrapper function that converts the "void*" parameters/returns
+// of the underlying C API into nice C++ function.
+//
+// Sample usage:
+//   void OnValue1(MyClosure* c, const MyHandlerData* d, int32_t val) {
+//     // do stuff ...
+//   }
+//
+//   // Handler that doesn't need any data bound to it.
+//   void OnValue2(MyClosure* c, int32_t val) {
+//     // do stuff ...
+//   }
+//
+//   // Handler that returns bool so it can return failure if necessary.
+//   bool OnValue3(MyClosure* c, int32_t val) {
+//     // do stuff ...
+//     return ok;
+//   }
+//
+//   // Member function handler.
+//   class MyClosure {
+//    public:
+//     void OnValue(int32_t val) {
+//       // do stuff ...
+//     }
+//   };
+//
+//   // Takes ownership of the MyHandlerData.
+//   handlers->SetInt32Handler(f1, UpbBind(OnValue1, new MyHandlerData(...)));
+//   handlers->SetInt32Handler(f2, UpbMakeHandler(OnValue2));
+//   handlers->SetInt32Handler(f1, UpbMakeHandler(OnValue3));
+//   handlers->SetInt32Handler(f2, UpbMakeHandler(&MyClosure::OnValue));
+
+#ifdef UPB_CXX11
+
+// In C++11, the "template" disambiguator can appear even outside templates,
+// so all calls can safely use this pair of macros.
+
+#define UpbMakeHandler(f) upb::MatchFunc(f).template GetFunc<f>()
+
+// We have to be careful to only evaluate "d" once.
+#define UpbBind(f, d) upb::MatchFunc(f).template GetFunc<f>((d))
+
+#else
+
+// Prior to C++11, the "template" disambiguator may only appear inside a
+// template, so the regular macro must not use "template"
+
+#define UpbMakeHandler(f) upb::MatchFunc(f).GetFunc<f>()
+
+#define UpbBind(f, d) upb::MatchFunc(f).GetFunc<f>((d))
+
+#endif  // UPB_CXX11
+
+// This macro must be used in C++98 for calls from inside a template.  But we
+// define this variant in all cases; code that wants to be compatible with both
+// C++98 and C++11 should always use this macro when calling from a template.
+#define UpbMakeHandlerT(f) upb::MatchFunc(f).template GetFunc<f>()
+
+// We have to be careful to only evaluate "d" once.
+#define UpbBindT(f, d) upb::MatchFunc(f).template GetFunc<f>((d))
+
+// Handler: a struct that contains the (handler, data, deleter) tuple that is
+// used to register all handlers.  Users can Make() these directly but it's
+// more convenient to use the UpbMakeHandler/UpbBind macros above.
+template <class T> class Handler {
+ public:
+  // The underlying, handler function signature that upb uses internally.
+  typedef T FuncPtr;
+
+  // Intentionally implicit.
+  template <class F> Handler(F func);
+  ~Handler();
+
+ private:
+  void AddCleanup(Handlers* h) const {
+    if (cleanup_func_) {
+      bool ok = h->AddCleanup(cleanup_data_, cleanup_func_);
+      UPB_ASSERT_VAR(ok, ok);
+    }
+  }
+
+  UPB_DISALLOW_COPY_AND_ASSIGN(Handler);
+  friend class Handlers;
+  FuncPtr handler_;
+  mutable HandlerAttributes attr_;
+  mutable bool registered_;
+  void *cleanup_data_;
+  upb_handlerfree *cleanup_func_;
+};
+
+}  // namespace upb
+
+#endif  // __cplusplus
+
+UPB_BEGIN_EXTERN_C
+
+// Native C API.
+
+// Handler function typedefs.
+typedef bool upb_startmsg_handlerfunc(void *c, const void*);
+typedef bool upb_endmsg_handlerfunc(void *c, const void *, upb_status *status);
+typedef void* upb_startfield_handlerfunc(void *c, const void *hd);
+typedef bool upb_endfield_handlerfunc(void *c, const void *hd);
+typedef bool upb_int32_handlerfunc(void *c, const void *hd, int32_t val);
+typedef bool upb_int64_handlerfunc(void *c, const void *hd, int64_t val);
+typedef bool upb_uint32_handlerfunc(void *c, const void *hd, uint32_t val);
+typedef bool upb_uint64_handlerfunc(void *c, const void *hd, uint64_t val);
+typedef bool upb_float_handlerfunc(void *c, const void *hd, float val);
+typedef bool upb_double_handlerfunc(void *c, const void *hd, double val);
+typedef bool upb_bool_handlerfunc(void *c, const void *hd, bool val);
+typedef void *upb_startstr_handlerfunc(void *c, const void *hd,
+                                       size_t size_hint);
+typedef size_t upb_string_handlerfunc(void *c, const void *hd, const char *buf,
+                                      size_t n, const upb_bufhandle* handle);
+
+// upb_bufhandle
+size_t upb_bufhandle_objofs(const upb_bufhandle *h);
+
+// upb_handlerattr
+void upb_handlerattr_init(upb_handlerattr *attr);
+void upb_handlerattr_uninit(upb_handlerattr *attr);
+
+bool upb_handlerattr_sethandlerdata(upb_handlerattr *attr, const void *hd);
+bool upb_handlerattr_setclosuretype(upb_handlerattr *attr, const void *type);
+const void *upb_handlerattr_closuretype(const upb_handlerattr *attr);
+bool upb_handlerattr_setreturnclosuretype(upb_handlerattr *attr,
+                                          const void *type);
+const void *upb_handlerattr_returnclosuretype(const upb_handlerattr *attr);
+bool upb_handlerattr_setalwaysok(upb_handlerattr *attr, bool alwaysok);
+bool upb_handlerattr_alwaysok(const upb_handlerattr *attr);
+
+UPB_INLINE const void *upb_handlerattr_handlerdata(
+    const upb_handlerattr *attr) {
+  return attr->handler_data_;
+}
+
+// upb_handlers
+typedef void upb_handlers_callback(const void *closure, upb_handlers *h);
+upb_handlers *upb_handlers_new(const upb_msgdef *m,
+                               const void *owner);
+const upb_handlers *upb_handlers_newfrozen(const upb_msgdef *m,
+                                           const void *owner,
+                                           upb_handlers_callback *callback,
+                                           const void *closure);
+bool upb_handlers_isfrozen(const upb_handlers *h);
+void upb_handlers_ref(const upb_handlers *h, const void *owner);
+void upb_handlers_unref(const upb_handlers *h, const void *owner);
+void upb_handlers_donateref(const upb_handlers *h, const void *from,
+                            const void *to);
+void upb_handlers_checkref(const upb_handlers *h, const void *owner);
+
+const upb_status *upb_handlers_status(upb_handlers *h);
+void upb_handlers_clearerr(upb_handlers *h);
+const upb_msgdef *upb_handlers_msgdef(const upb_handlers *h);
+bool upb_handlers_addcleanup(upb_handlers *h, void *p, upb_handlerfree *hfree);
+
+bool upb_handlers_setstartmsg(upb_handlers *h, upb_startmsg_handlerfunc *func,
+                              upb_handlerattr *attr);
+bool upb_handlers_setendmsg(upb_handlers *h, upb_endmsg_handlerfunc *func,
+                            upb_handlerattr *attr);
+bool upb_handlers_setint32(upb_handlers *h, const upb_fielddef *f,
+                           upb_int32_handlerfunc *func, upb_handlerattr *attr);
+bool upb_handlers_setint64(upb_handlers *h, const upb_fielddef *f,
+                           upb_int64_handlerfunc *func, upb_handlerattr *attr);
+bool upb_handlers_setuint32(upb_handlers *h, const upb_fielddef *f,
+                            upb_uint32_handlerfunc *func,
+                            upb_handlerattr *attr);
+bool upb_handlers_setuint64(upb_handlers *h, const upb_fielddef *f,
+                            upb_uint64_handlerfunc *func,
+                            upb_handlerattr *attr);
+bool upb_handlers_setfloat(upb_handlers *h, const upb_fielddef *f,
+                           upb_float_handlerfunc *func, upb_handlerattr *attr);
+bool upb_handlers_setdouble(upb_handlers *h, const upb_fielddef *f,
+                            upb_double_handlerfunc *func,
+                            upb_handlerattr *attr);
+bool upb_handlers_setbool(upb_handlers *h, const upb_fielddef *f,
+                          upb_bool_handlerfunc *func,
+                          upb_handlerattr *attr);
+bool upb_handlers_setstartstr(upb_handlers *h, const upb_fielddef *f,
+                              upb_startstr_handlerfunc *func,
+                              upb_handlerattr *attr);
+bool upb_handlers_setstring(upb_handlers *h, const upb_fielddef *f,
+                            upb_string_handlerfunc *func,
+                            upb_handlerattr *attr);
+bool upb_handlers_setendstr(upb_handlers *h, const upb_fielddef *f,
+                            upb_endfield_handlerfunc *func,
+                            upb_handlerattr *attr);
+bool upb_handlers_setstartseq(upb_handlers *h, const upb_fielddef *f,
+                              upb_startfield_handlerfunc *func,
+                              upb_handlerattr *attr);
+bool upb_handlers_setstartsubmsg(upb_handlers *h, const upb_fielddef *f,
+                                 upb_startfield_handlerfunc *func,
+                                 upb_handlerattr *attr);
+bool upb_handlers_setendsubmsg(upb_handlers *h, const upb_fielddef *f,
+                               upb_endfield_handlerfunc *func,
+                               upb_handlerattr *attr);
+bool upb_handlers_setendseq(upb_handlers *h, const upb_fielddef *f,
+                            upb_endfield_handlerfunc *func,
+                            upb_handlerattr *attr);
+
+bool upb_handlers_setsubhandlers(upb_handlers *h, const upb_fielddef *f,
+                                 const upb_handlers *sub);
+const upb_handlers *upb_handlers_getsubhandlers(const upb_handlers *h,
+                                                const upb_fielddef *f);
+const upb_handlers *upb_handlers_getsubhandlers_sel(const upb_handlers *h,
+                                                    upb_selector_t sel);
+
+UPB_INLINE upb_func *upb_handlers_gethandler(const upb_handlers *h,
+                                             upb_selector_t s) {
+  return (upb_func *)h->table[s].func;
+}
+
+bool upb_handlers_getattr(const upb_handlers *h, upb_selector_t s,
+                          upb_handlerattr *attr);
+
+UPB_INLINE const void *upb_handlers_gethandlerdata(const upb_handlers *h,
+                                                   upb_selector_t s) {
+  return upb_handlerattr_handlerdata(&h->table[s].attr);
+}
+
+// Handler types for single fields.
+// Right now we only have one for TYPE_BYTES but ones for other types
+// should follow.
+//
+// These follow the same handlers protocol for fields of a message.
+UPB_DEFINE_CLASS0(upb::BytesHandler,
+ public:
+  BytesHandler();
+  ~BytesHandler();
+,
+UPB_DEFINE_STRUCT0(upb_byteshandler,
+  upb_handlers_tabent table[3];
+));
+
+void upb_byteshandler_init(upb_byteshandler *h);
+void upb_byteshandler_uninit(upb_byteshandler *h);
+
+// Caller must ensure that "d" outlives the handlers.
+// TODO(haberman): support handlerfree function for the data.
+// TODO(haberman): should this have a "freeze" operation?  It's not necessary
+// for memory management, but could be useful to force immutability and provide
+// a convenient moment to verify that all registration succeeded.
+bool upb_byteshandler_setstartstr(upb_byteshandler *h,
+                                  upb_startstr_handlerfunc *func, void *d);
+bool upb_byteshandler_setstring(upb_byteshandler *h,
+                                upb_string_handlerfunc *func, void *d);
+bool upb_byteshandler_setendstr(upb_byteshandler *h,
+                                upb_endfield_handlerfunc *func, void *d);
+
+// "Static" methods
+bool upb_handlers_freeze(upb_handlers *const *handlers, int n, upb_status *s);
+upb_handlertype_t upb_handlers_getprimitivehandlertype(const upb_fielddef *f);
+bool upb_handlers_getselector(const upb_fielddef *f, upb_handlertype_t type,
+                              upb_selector_t *s);
+UPB_INLINE upb_selector_t upb_handlers_getendselector(upb_selector_t start) {
+  return start + 1;
+}
+
+// Internal-only.
+uint32_t upb_handlers_selectorbaseoffset(const upb_fielddef *f);
+uint32_t upb_handlers_selectorcount(const upb_fielddef *f);
+
+UPB_END_EXTERN_C
+
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2011-2012 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * Inline definitions for handlers.h, which are particularly long and a bit
+ * tricky.
+ */
+
+#ifndef UPB_HANDLERS_INL_H_
+#define UPB_HANDLERS_INL_H_
+
+#include <limits.h>
+
+// Type detection and typedefs for integer types.
+// For platforms where there are multiple 32-bit or 64-bit types, we need to be
+// able to enumerate them so we can properly create overloads for all variants.
+//
+// If any platform existed where there were three integer types with the same
+// size, this would have to become more complicated.  For example, short, int,
+// and long could all be 32-bits.  Even more diabolically, short, int, long,
+// and long long could all be 64 bits and still be standard-compliant.
+// However, few platforms are this strange, and it's unlikely that upb will be
+// used on the strangest ones.
+
+// Can't count on stdint.h limits like INT32_MAX, because in C++ these are
+// only defined when __STDC_LIMIT_MACROS are defined before the *first* include
+// of stdint.h.  We can't guarantee that someone else didn't include these first
+// without defining __STDC_LIMIT_MACROS.
+#define UPB_INT32_MAX 0x7fffffffLL
+#define UPB_INT32_MIN (-UPB_INT32_MAX - 1)
+#define UPB_INT64_MAX 0x7fffffffffffffffLL
+#define UPB_INT64_MIN (-UPB_INT64_MAX - 1)
+
+#if INT_MAX == UPB_INT32_MAX && INT_MIN == UPB_INT32_MIN
+#define UPB_INT_IS_32BITS 1
+#endif
+
+#if LONG_MAX == UPB_INT32_MAX && LONG_MIN == UPB_INT32_MIN
+#define UPB_LONG_IS_32BITS 1
+#endif
+
+#if LONG_MAX == UPB_INT64_MAX && LONG_MIN == UPB_INT64_MIN
+#define UPB_LONG_IS_64BITS 1
+#endif
+
+#if LLONG_MAX == UPB_INT64_MAX && LLONG_MIN == UPB_INT64_MIN
+#define UPB_LLONG_IS_64BITS 1
+#endif
+
+// We use macros instead of typedefs so we can undefine them later and avoid
+// leaking them outside this header file.
+#if UPB_INT_IS_32BITS
+#define UPB_INT32_T int
+#define UPB_UINT32_T unsigned int
+
+#if UPB_LONG_IS_32BITS
+#define UPB_TWO_32BIT_TYPES 1
+#define UPB_INT32ALT_T long
+#define UPB_UINT32ALT_T unsigned long
+#endif  // UPB_LONG_IS_32BITS
+
+#elif UPB_LONG_IS_32BITS  // && !UPB_INT_IS_32BITS
+#define UPB_INT32_T long
+#define UPB_UINT32_T unsigned long
+#endif  // UPB_INT_IS_32BITS
+
+
+#if UPB_LONG_IS_64BITS
+#define UPB_INT64_T long
+#define UPB_UINT64_T unsigned long
+
+#if UPB_LLONG_IS_64BITS
+#define UPB_TWO_64BIT_TYPES 1
+#define UPB_INT64ALT_T long long
+#define UPB_UINT64ALT_T unsigned long long
+#endif  // UPB_LLONG_IS_64BITS
+
+#elif UPB_LLONG_IS_64BITS  // && !UPB_LONG_IS_64BITS
+#define UPB_INT64_T long long
+#define UPB_UINT64_T unsigned long long
+#endif  // UPB_LONG_IS_64BITS
+
+#undef UPB_INT32_MAX
+#undef UPB_INT32_MIN
+#undef UPB_INT64_MAX
+#undef UPB_INT64_MIN
+#undef UPB_INT_IS_32BITS
+#undef UPB_LONG_IS_32BITS
+#undef UPB_LONG_IS_64BITS
+#undef UPB_LLONG_IS_64BITS
+
+// C inline methods.
+
+// upb_bufhandle
+UPB_INLINE void upb_bufhandle_init(upb_bufhandle *h) {
+  h->obj_ = NULL;
+  h->objtype_ = NULL;
+  h->buf_ = NULL;
+  h->objofs_ = 0;
+}
+UPB_INLINE void upb_bufhandle_uninit(upb_bufhandle *h) {
+  UPB_UNUSED(h);
+}
+UPB_INLINE void upb_bufhandle_setobj(upb_bufhandle *h, const void *obj,
+                                     const void *type) {
+  h->obj_ = obj;
+  h->objtype_ = type;
+}
+UPB_INLINE void upb_bufhandle_setbuf(upb_bufhandle *h, const char *buf,
+                                     size_t ofs) {
+  h->buf_ = buf;
+  h->objofs_ = ofs;
+}
+UPB_INLINE const void *upb_bufhandle_obj(const upb_bufhandle *h) {
+  return h->obj_;
+}
+UPB_INLINE const void *upb_bufhandle_objtype(const upb_bufhandle *h) {
+  return h->objtype_;
+}
+UPB_INLINE const char *upb_bufhandle_buf(const upb_bufhandle *h) {
+  return h->buf_;
+}
+
+
+#ifdef __cplusplus
+
+namespace upb {
+
+typedef void CleanupFunc(void *ptr);
+
+// Template to remove "const" from "const T*" and just return "T*".
+//
+// We define a nonsense default because otherwise it will fail to instantiate as
+// a function parameter type even in cases where we don't expect any caller to
+// actually match the overload.
+class CouldntRemoveConst {};
+template <class T> struct remove_constptr { typedef CouldntRemoveConst type; };
+template <class T> struct remove_constptr<const T *> { typedef T *type; };
+
+// Template that we use below to remove a template specialization from
+// consideration if it matches a specific type.
+template <class T, class U> struct disable_if_same { typedef void Type; };
+template <class T> struct disable_if_same<T, T> {};
+
+template <class T> void DeletePointer(void *p) { delete static_cast<T>(p); }
+
+template <class T1, class T2>
+struct FirstUnlessVoid {
+  typedef T1 value;
+};
+
+template <class T2>
+struct FirstUnlessVoid<void, T2> {
+  typedef T2 value;
+};
+
+template<class T, class U>
+struct is_same {
+  static bool value;
+};
+
+template<class T>
+struct is_same<T, T> {
+  static bool value;
+};
+
+template<class T, class U>
+bool is_same<T, U>::value = false;
+
+template<class T>
+bool is_same<T, T>::value = true;
+
+// FuncInfo ////////////////////////////////////////////////////////////////////
+
+// Info about the user's original, pre-wrapped function.
+template <class C, class R = void>
+struct FuncInfo {
+  // The type of the closure that the function takes (its first param).
+  typedef C Closure;
+
+  // The return type.
+  typedef R Return;
+};
+
+// Func ////////////////////////////////////////////////////////////////////////
+
+// Func1, Func2, Func3: Template classes representing a function and its
+// signature.
+//
+// Since the function is a template parameter, calling the function can be
+// inlined at compile-time and does not require a function pointer at runtime.
+// These functions are not bound to a handler data so have no data or cleanup
+// handler.
+struct UnboundFunc {
+  CleanupFunc *GetCleanup() { return NULL; }
+  void *GetData() { return NULL; }
+};
+
+template <class R, class P1, R F(P1), class I>
+struct Func1 : public UnboundFunc {
+  typedef R Return;
+  typedef I FuncInfo;
+  static R Call(P1 p1) { return F(p1); }
+};
+
+template <class R, class P1, class P2, R F(P1, P2), class I>
+struct Func2 : public UnboundFunc {
+  typedef R Return;
+  typedef I FuncInfo;
+  static R Call(P1 p1, P2 p2) { return F(p1, p2); }
+};
+
+template <class R, class P1, class P2, class P3, R F(P1, P2, P3), class I>
+struct Func3 : public UnboundFunc {
+  typedef R Return;
+  typedef I FuncInfo;
+  static R Call(P1 p1, P2 p2, P3 p3) { return F(p1, p2, p3); }
+};
+
+template <class R, class P1, class P2, class P3, class P4, R F(P1, P2, P3, P4),
+          class I>
+struct Func4 : public UnboundFunc {
+  typedef R Return;
+  typedef I FuncInfo;
+  static R Call(P1 p1, P2 p2, P3 p3, P4 p4) { return F(p1, p2, p3, p4); }
+};
+
+template <class R, class P1, class P2, class P3, class P4, class P5,
+          R F(P1, P2, P3, P4, P5), class I>
+struct Func5 : public UnboundFunc {
+  typedef R Return;
+  typedef I FuncInfo;
+  static R Call(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) {
+    return F(p1, p2, p3, p4, p5);
+  }
+};
+
+// BoundFunc ///////////////////////////////////////////////////////////////////
+
+// BoundFunc2, BoundFunc3: Like Func2/Func3 except also contains a value that
+// shall be bound to the function's second parameter.
+//
+// Note that the second parameter is a const pointer, but our stored bound value
+// is non-const so we can free it when the handlers are destroyed.
+template <class T>
+struct BoundFunc {
+  typedef typename remove_constptr<T>::type MutableP2;
+  explicit BoundFunc(MutableP2 data_) : data(data_) {}
+  CleanupFunc *GetCleanup() { return &DeletePointer<MutableP2>; }
+  MutableP2 GetData() { return data; }
+  MutableP2 data;
+};
+
+template <class R, class P1, class P2, R F(P1, P2), class I>
+struct BoundFunc2 : public BoundFunc<P2> {
+  typedef BoundFunc<P2> Base;
+  typedef I FuncInfo;
+  explicit BoundFunc2(typename Base::MutableP2 arg) : Base(arg) {}
+};
+
+template <class R, class P1, class P2, class P3, R F(P1, P2, P3), class I>
+struct BoundFunc3 : public BoundFunc<P2> {
+  typedef BoundFunc<P2> Base;
+  typedef I FuncInfo;
+  explicit BoundFunc3(typename Base::MutableP2 arg) : Base(arg) {}
+};
+
+template <class R, class P1, class P2, class P3, class P4, R F(P1, P2, P3, P4),
+          class I>
+struct BoundFunc4 : public BoundFunc<P2> {
+  typedef BoundFunc<P2> Base;
+  typedef I FuncInfo;
+  explicit BoundFunc4(typename Base::MutableP2 arg) : Base(arg) {}
+};
+
+template <class R, class P1, class P2, class P3, class P4, class P5,
+          R F(P1, P2, P3, P4, P5), class I>
+struct BoundFunc5 : public BoundFunc<P2> {
+  typedef BoundFunc<P2> Base;
+  typedef I FuncInfo;
+  explicit BoundFunc5(typename Base::MutableP2 arg) : Base(arg) {}
+};
+
+// FuncSig /////////////////////////////////////////////////////////////////////
+
+// FuncSig1, FuncSig2, FuncSig3: template classes reflecting a function
+// *signature*, but without a specific function attached.
+//
+// These classes contain member functions that can be invoked with a
+// specific function to return a Func/BoundFunc class.
+template <class R, class P1>
+struct FuncSig1 {
+  template <R F(P1)>
+  Func1<R, P1, F, FuncInfo<P1, R> > GetFunc() {
+    return Func1<R, P1, F, FuncInfo<P1, R> >();
+  }
+};
+
+template <class R, class P1, class P2>
+struct FuncSig2 {
+  template <R F(P1, P2)>
+  Func2<R, P1, P2, F, FuncInfo<P1, R> > GetFunc() {
+    return Func2<R, P1, P2, F, FuncInfo<P1, R> >();
+  }
+
+  template <R F(P1, P2)>
+  BoundFunc2<R, P1, P2, F, FuncInfo<P1, R> > GetFunc(
+      typename remove_constptr<P2>::type param2) {
+    return BoundFunc2<R, P1, P2, F, FuncInfo<P1, R> >(param2);
+  }
+};
+
+template <class R, class P1, class P2, class P3>
+struct FuncSig3 {
+  template <R F(P1, P2, P3)>
+  Func3<R, P1, P2, P3, F, FuncInfo<P1, R> > GetFunc() {
+    return Func3<R, P1, P2, P3, F, FuncInfo<P1, R> >();
+  }
+
+  template <R F(P1, P2, P3)>
+  BoundFunc3<R, P1, P2, P3, F, FuncInfo<P1, R> > GetFunc(
+      typename remove_constptr<P2>::type param2) {
+    return BoundFunc3<R, P1, P2, P3, F, FuncInfo<P1, R> >(param2);
+  }
+};
+
+template <class R, class P1, class P2, class P3, class P4>
+struct FuncSig4 {
+  template <R F(P1, P2, P3, P4)>
+  Func4<R, P1, P2, P3, P4, F, FuncInfo<P1, R> > GetFunc() {
+    return Func4<R, P1, P2, P3, P4, F, FuncInfo<P1, R> >();
+  }
+
+  template <R F(P1, P2, P3, P4)>
+  BoundFunc4<R, P1, P2, P3, P4, F, FuncInfo<P1, R> > GetFunc(
+      typename remove_constptr<P2>::type param2) {
+    return BoundFunc4<R, P1, P2, P3, P4, F, FuncInfo<P1, R> >(param2);
+  }
+};
+
+template <class R, class P1, class P2, class P3, class P4, class P5>
+struct FuncSig5 {
+  template <R F(P1, P2, P3, P4, P5)>
+  Func5<R, P1, P2, P3, P4, P5, F, FuncInfo<P1, R> > GetFunc() {
+    return Func5<R, P1, P2, P3, P4, P5, F, FuncInfo<P1, R> >();
+  }
+
+  template <R F(P1, P2, P3, P4, P5)>
+  BoundFunc5<R, P1, P2, P3, P4, P5, F, FuncInfo<P1, R> > GetFunc(
+      typename remove_constptr<P2>::type param2) {
+    return BoundFunc5<R, P1, P2, P3, P4, P5, F, FuncInfo<P1, R> >(param2);
+  }
+};
+
+// Overloaded template function that can construct the appropriate FuncSig*
+// class given a function pointer by deducing the template parameters.
+template <class R, class P1>
+inline FuncSig1<R, P1> MatchFunc(R (*f)(P1)) {
+  UPB_UNUSED(f);  // Only used for template parameter deduction.
+  return FuncSig1<R, P1>();
+}
+
+template <class R, class P1, class P2>
+inline FuncSig2<R, P1, P2> MatchFunc(R (*f)(P1, P2)) {
+  UPB_UNUSED(f);  // Only used for template parameter deduction.
+  return FuncSig2<R, P1, P2>();
+}
+
+template <class R, class P1, class P2, class P3>
+inline FuncSig3<R, P1, P2, P3> MatchFunc(R (*f)(P1, P2, P3)) {
+  UPB_UNUSED(f);  // Only used for template parameter deduction.
+  return FuncSig3<R, P1, P2, P3>();
+}
+
+template <class R, class P1, class P2, class P3, class P4>
+inline FuncSig4<R, P1, P2, P3, P4> MatchFunc(R (*f)(P1, P2, P3, P4)) {
+  UPB_UNUSED(f);  // Only used for template parameter deduction.
+  return FuncSig4<R, P1, P2, P3, P4>();
+}
+
+template <class R, class P1, class P2, class P3, class P4, class P5>
+inline FuncSig5<R, P1, P2, P3, P4, P5> MatchFunc(R (*f)(P1, P2, P3, P4, P5)) {
+  UPB_UNUSED(f);  // Only used for template parameter deduction.
+  return FuncSig5<R, P1, P2, P3, P4, P5>();
+}
+
+// MethodSig ///////////////////////////////////////////////////////////////////
+
+// CallMethod*: a function template that calls a given method.
+template <class R, class C, R (C::*F)()>
+R CallMethod0(C *obj) {
+  return ((*obj).*F)();
+}
+
+template <class R, class C, class P1, R (C::*F)(P1)>
+R CallMethod1(C *obj, P1 arg1) {
+  return ((*obj).*F)(arg1);
+}
+
+template <class R, class C, class P1, class P2, R (C::*F)(P1, P2)>
+R CallMethod2(C *obj, P1 arg1, P2 arg2) {
+  return ((*obj).*F)(arg1, arg2);
+}
+
+template <class R, class C, class P1, class P2, class P3, R (C::*F)(P1, P2, P3)>
+R CallMethod3(C *obj, P1 arg1, P2 arg2, P3 arg3) {
+  return ((*obj).*F)(arg1, arg2, arg3);
+}
+
+template <class R, class C, class P1, class P2, class P3, class P4,
+          R (C::*F)(P1, P2, P3, P4)>
+R CallMethod4(C *obj, P1 arg1, P2 arg2, P3 arg3, P4 arg4) {
+  return ((*obj).*F)(arg1, arg2, arg3, arg4);
+}
+
+// MethodSig: like FuncSig, but for member functions.
+//
+// GetFunc() returns a normal FuncN object, so after calling GetFunc() no
+// more logic is required to special-case methods.
+template <class R, class C>
+struct MethodSig0 {
+  template <R (C::*F)()>
+  Func1<R, C *, CallMethod0<R, C, F>, FuncInfo<C *, R> > GetFunc() {
+    return Func1<R, C *, CallMethod0<R, C, F>, FuncInfo<C *, R> >();
+  }
+};
+
+template <class R, class C, class P1>
+struct MethodSig1 {
+  template <R (C::*F)(P1)>
+  Func2<R, C *, P1, CallMethod1<R, C, P1, F>, FuncInfo<C *, R> > GetFunc() {
+    return Func2<R, C *, P1, CallMethod1<R, C, P1, F>, FuncInfo<C *, R> >();
+  }
+
+  template <R (C::*F)(P1)>
+  BoundFunc2<R, C *, P1, CallMethod1<R, C, P1, F>, FuncInfo<C *, R> > GetFunc(
+      typename remove_constptr<P1>::type param1) {
+    return BoundFunc2<R, C *, P1, CallMethod1<R, C, P1, F>, FuncInfo<C *, R> >(
+        param1);
+  }
+};
+
+template <class R, class C, class P1, class P2>
+struct MethodSig2 {
+  template <R (C::*F)(P1, P2)>
+  Func3<R, C *, P1, P2, CallMethod2<R, C, P1, P2, F>, FuncInfo<C *, R> >
+  GetFunc() {
+    return Func3<R, C *, P1, P2, CallMethod2<R, C, P1, P2, F>,
+                 FuncInfo<C *, R> >();
+  }
+
+  template <R (C::*F)(P1, P2)>
+  BoundFunc3<R, C *, P1, P2, CallMethod2<R, C, P1, P2, F>, FuncInfo<C *, R> >
+  GetFunc(typename remove_constptr<P1>::type param1) {
+    return BoundFunc3<R, C *, P1, P2, CallMethod2<R, C, P1, P2, F>,
+                      FuncInfo<C *, R> >(param1);
+  }
+};
+
+template <class R, class C, class P1, class P2, class P3>
+struct MethodSig3 {
+  template <R (C::*F)(P1, P2, P3)>
+  Func4<R, C *, P1, P2, P3, CallMethod3<R, C, P1, P2, P3, F>, FuncInfo<C *, R> >
+  GetFunc() {
+    return Func4<R, C *, P1, P2, P3, CallMethod3<R, C, P1, P2, P3, F>,
+                 FuncInfo<C *, R> >();
+  }
+
+  template <R (C::*F)(P1, P2, P3)>
+  BoundFunc4<R, C *, P1, P2, P3, CallMethod3<R, C, P1, P2, P3, F>,
+             FuncInfo<C *, R> >
+  GetFunc(typename remove_constptr<P1>::type param1) {
+    return BoundFunc4<R, C *, P1, P2, P3, CallMethod3<R, C, P1, P2, P3, F>,
+                      FuncInfo<C *, R> >(param1);
+  }
+};
+
+template <class R, class C, class P1, class P2, class P3, class P4>
+struct MethodSig4 {
+  template <R (C::*F)(P1, P2, P3, P4)>
+  Func5<R, C *, P1, P2, P3, P4, CallMethod4<R, C, P1, P2, P3, P4, F>,
+        FuncInfo<C *, R> >
+  GetFunc() {
+    return Func5<R, C *, P1, P2, P3, P4, CallMethod4<R, C, P1, P2, P3, P4, F>,
+                 FuncInfo<C *, R> >();
+  }
+
+  template <R (C::*F)(P1, P2, P3, P4)>
+  BoundFunc5<R, C *, P1, P2, P3, P4, CallMethod4<R, C, P1, P2, P3, P4, F>,
+             FuncInfo<C *, R> >
+  GetFunc(typename remove_constptr<P1>::type param1) {
+    return BoundFunc5<R, C *, P1, P2, P3, P4,
+                      CallMethod4<R, C, P1, P2, P3, P4, F>, FuncInfo<C *, R> >(
+        param1);
+  }
+};
+
+template <class R, class C>
+inline MethodSig0<R, C> MatchFunc(R (C::*f)()) {
+  UPB_UNUSED(f);  // Only used for template parameter deduction.
+  return MethodSig0<R, C>();
+}
+
+template <class R, class C, class P1>
+inline MethodSig1<R, C, P1> MatchFunc(R (C::*f)(P1)) {
+  UPB_UNUSED(f);  // Only used for template parameter deduction.
+  return MethodSig1<R, C, P1>();
+}
+
+template <class R, class C, class P1, class P2>
+inline MethodSig2<R, C, P1, P2> MatchFunc(R (C::*f)(P1, P2)) {
+  UPB_UNUSED(f);  // Only used for template parameter deduction.
+  return MethodSig2<R, C, P1, P2>();
+}
+
+template <class R, class C, class P1, class P2, class P3>
+inline MethodSig3<R, C, P1, P2, P3> MatchFunc(R (C::*f)(P1, P2, P3)) {
+  UPB_UNUSED(f);  // Only used for template parameter deduction.
+  return MethodSig3<R, C, P1, P2, P3>();
+}
+
+template <class R, class C, class P1, class P2, class P3, class P4>
+inline MethodSig4<R, C, P1, P2, P3, P4> MatchFunc(R (C::*f)(P1, P2, P3, P4)) {
+  UPB_UNUSED(f);  // Only used for template parameter deduction.
+  return MethodSig4<R, C, P1, P2, P3, P4>();
+}
+
+// MaybeWrapReturn /////////////////////////////////////////////////////////////
+
+// Template class that attempts to wrap the return value of the function so it
+// matches the expected type.  There are two main adjustments it may make:
+//
+//   1. If the function returns void, make it return the expected type and with
+//      a value that always indicates success.
+//   2. If the function is expected to return void* but doesn't, wrap it so it
+//      does (either by returning the closure param if the wrapped function
+//      returns void or by casting a different pointer type to void* for
+//      return).
+
+// Template parameters are FuncN type and desired return type.
+template <class F, class R, class Enable = void>
+struct MaybeWrapReturn;
+
+// If the return type matches, return the given function unwrapped.
+template <class F>
+struct MaybeWrapReturn<F, typename F::Return> {
+  typedef F Func;
+};
+
+// Function wrapper that munges the return value from void to (bool)true.
+template <class P1, class P2, void F(P1, P2)>
+bool ReturnTrue2(P1 p1, P2 p2) {
+  F(p1, p2);
+  return true;
+}
+
+template <class P1, class P2, class P3, void F(P1, P2, P3)>
+bool ReturnTrue3(P1 p1, P2 p2, P3 p3) {
+  F(p1, p2, p3);
+  return true;
+}
+
+// Function wrapper that munges the return value from void to (void*)arg1
+template <class P1, class P2, void F(P1, P2)>
+void *ReturnClosure2(P1 p1, P2 p2) {
+  F(p1, p2);
+  return p1;
+}
+
+template <class P1, class P2, class P3, void F(P1, P2, P3)>
+void *ReturnClosure3(P1 p1, P2 p2, P3 p3) {
+  F(p1, p2, p3);
+  return p1;
+}
+
+// Function wrapper that munges the return value from R to void*.
+template <class R, class P1, class P2, R F(P1, P2)>
+void *CastReturnToVoidPtr2(P1 p1, P2 p2) {
+  return F(p1, p2);
+}
+
+template <class R, class P1, class P2, class P3, R F(P1, P2, P3)>
+void *CastReturnToVoidPtr3(P1 p1, P2 p2, P3 p3) {
+  return F(p1, p2, p3);
+}
+
+// Function wrapper that munges the return value from bool to void*.
+template <class P1, class P2, bool F(P1, P2)>
+void *ReturnClosureOrBreak2(P1 p1, P2 p2) {
+  return F(p1, p2) ? p1 : UPB_BREAK;
+}
+
+template <class P1, class P2, class P3, bool F(P1, P2, P3)>
+void *ReturnClosureOrBreak3(P1 p1, P2 p2, P3 p3) {
+  return F(p1, p2, p3) ? p1 : UPB_BREAK;
+}
+
+// For the string callback, which takes five params, returns the size param.
+template <class P1, class P2,
+          void F(P1, P2, const char *, size_t, const BufferHandle *)>
+size_t ReturnStringLen(P1 p1, P2 p2, const char *p3, size_t p4,
+                       const BufferHandle *p5) {
+  F(p1, p2, p3, p4, p5);
+  return p4;
+}
+
+// For the string callback, which takes five params, returns the size param or
+// zero.
+template <class P1, class P2,
+          bool F(P1, P2, const char *, size_t, const BufferHandle *)>
+size_t ReturnNOr0(P1 p1, P2 p2, const char *p3, size_t p4,
+                  const BufferHandle *p5) {
+  return F(p1, p2, p3, p4, p5) ? p4 : 0;
+}
+
+// If we have a function returning void but want a function returning bool, wrap
+// it in a function that returns true.
+template <class P1, class P2, void F(P1, P2), class I>
+struct MaybeWrapReturn<Func2<void, P1, P2, F, I>, bool> {
+  typedef Func2<bool, P1, P2, ReturnTrue2<P1, P2, F>, I> Func;
+};
+
+template <class P1, class P2, class P3, void F(P1, P2, P3), class I>
+struct MaybeWrapReturn<Func3<void, P1, P2, P3, F, I>, bool> {
+  typedef Func3<bool, P1, P2, P3, ReturnTrue3<P1, P2, P3, F>, I> Func;
+};
+
+// If our function returns void but we want one returning void*, wrap it in a
+// function that returns the first argument.
+template <class P1, class P2, void F(P1, P2), class I>
+struct MaybeWrapReturn<Func2<void, P1, P2, F, I>, void *> {
+  typedef Func2<void *, P1, P2, ReturnClosure2<P1, P2, F>, I> Func;
+};
+
+template <class P1, class P2, class P3, void F(P1, P2, P3), class I>
+struct MaybeWrapReturn<Func3<void, P1, P2, P3, F, I>, void *> {
+  typedef Func3<void *, P1, P2, P3, ReturnClosure3<P1, P2, P3, F>, I> Func;
+};
+
+// If our function returns R* but we want one returning void*, wrap it in a
+// function that casts to void*.
+template <class R, class P1, class P2, R *F(P1, P2), class I>
+struct MaybeWrapReturn<Func2<R *, P1, P2, F, I>, void *,
+                       typename disable_if_same<R *, void *>::Type> {
+  typedef Func2<void *, P1, P2, CastReturnToVoidPtr2<R *, P1, P2, F>, I> Func;
+};
+
+template <class R, class P1, class P2, class P3, R *F(P1, P2, P3), class I>
+struct MaybeWrapReturn<Func3<R *, P1, P2, P3, F, I>, void *,
+                       typename disable_if_same<R *, void *>::Type> {
+  typedef Func3<void *, P1, P2, P3, CastReturnToVoidPtr3<R *, P1, P2, P3, F>, I>
+      Func;
+};
+
+// If our function returns bool but we want one returning void*, wrap it in a
+// function that returns either the first param or UPB_BREAK.
+template <class P1, class P2, bool F(P1, P2), class I>
+struct MaybeWrapReturn<Func2<bool, P1, P2, F, I>, void *> {
+  typedef Func2<void *, P1, P2, ReturnClosureOrBreak2<P1, P2, F>, I> Func;
+};
+
+template <class P1, class P2, class P3, bool F(P1, P2, P3), class I>
+struct MaybeWrapReturn<Func3<bool, P1, P2, P3, F, I>, void *> {
+  typedef Func3<void *, P1, P2, P3, ReturnClosureOrBreak3<P1, P2, P3, F>, I>
+      Func;
+};
+
+// If our function returns void but we want one returning size_t, wrap it in a
+// function that returns the size argument.
+template <class P1, class P2,
+          void F(P1, P2, const char *, size_t, const BufferHandle *), class I>
+struct MaybeWrapReturn<
+    Func5<void, P1, P2, const char *, size_t, const BufferHandle *, F, I>,
+          size_t> {
+  typedef Func5<size_t, P1, P2, const char *, size_t, const BufferHandle *,
+                ReturnStringLen<P1, P2, F>, I> Func;
+};
+
+// If our function returns bool but we want one returning size_t, wrap it in a
+// function that returns either 0 or the buf size.
+template <class P1, class P2,
+          bool F(P1, P2, const char *, size_t, const BufferHandle *), class I>
+struct MaybeWrapReturn<
+    Func5<bool, P1, P2, const char *, size_t, const BufferHandle *, F, I>,
+    size_t> {
+  typedef Func5<size_t, P1, P2, const char *, size_t, const BufferHandle *,
+                ReturnNOr0<P1, P2, F>, I> Func;
+};
+
+// ConvertParams ///////////////////////////////////////////////////////////////
+
+// Template class that converts the function parameters if necessary, and
+// ignores the HandlerData parameter if appropriate.
+//
+// Template parameter is the are FuncN function type.
+template <class F, class T>
+struct ConvertParams;
+
+// Function that discards the handler data parameter.
+template <class R, class P1, R F(P1)>
+R IgnoreHandlerData2(void *p1, const void *hd) {
+  UPB_UNUSED(hd);
+  return F(static_cast<P1>(p1));
+}
+
+template <class R, class P1, class P2Wrapper, class P2Wrapped,
+          R F(P1, P2Wrapped)>
+R IgnoreHandlerData3(void *p1, const void *hd, P2Wrapper p2) {
+  UPB_UNUSED(hd);
+  return F(static_cast<P1>(p1), p2);
+}
+
+template <class R, class P1, class P2, class P3, R F(P1, P2, P3)>
+R IgnoreHandlerData4(void *p1, const void *hd, P2 p2, P3 p3) {
+  UPB_UNUSED(hd);
+  return F(static_cast<P1>(p1), p2, p3);
+}
+
+template <class R, class P1, class P2, class P3, class P4, R F(P1, P2, P3, P4)>
+R IgnoreHandlerData5(void *p1, const void *hd, P2 p2, P3 p3, P4 p4) {
+  UPB_UNUSED(hd);
+  return F(static_cast<P1>(p1), p2, p3, p4);
+}
+
+template <class R, class P1, R F(P1, const char*, size_t)>
+R IgnoreHandlerDataIgnoreHandle(void *p1, const void *hd, const char *p2,
+                                size_t p3, const BufferHandle *handle) {
+  UPB_UNUSED(hd);
+  UPB_UNUSED(handle);
+  return F(static_cast<P1>(p1), p2, p3);
+}
+
+// Function that casts the handler data parameter.
+template <class R, class P1, class P2, R F(P1, P2)>
+R CastHandlerData2(void *c, const void *hd) {
+  return F(static_cast<P1>(c), static_cast<P2>(hd));
+}
+
+template <class R, class P1, class P2, class P3Wrapper, class P3Wrapped,
+          R F(P1, P2, P3Wrapped)>
+R CastHandlerData3(void *c, const void *hd, P3Wrapper p3) {
+  return F(static_cast<P1>(c), static_cast<P2>(hd), p3);
+}
+
+template <class R, class P1, class P2, class P3, class P4, class P5,
+          R F(P1, P2, P3, P4, P5)>
+R CastHandlerData5(void *c, const void *hd, P3 p3, P4 p4, P5 p5) {
+  return F(static_cast<P1>(c), static_cast<P2>(hd), p3, p4, p5);
+}
+
+template <class R, class P1, class P2, R F(P1, P2, const char *, size_t)>
+R CastHandlerDataIgnoreHandle(void *c, const void *hd, const char *p3,
+                              size_t p4, const BufferHandle *handle) {
+  UPB_UNUSED(handle);
+  return F(static_cast<P1>(c), static_cast<P2>(hd), p3, p4);
+}
+
+// For unbound functions, ignore the handler data.
+template <class R, class P1, R F(P1), class I, class T>
+struct ConvertParams<Func1<R, P1, F, I>, T> {
+  typedef Func2<R, void *, const void *, IgnoreHandlerData2<R, P1, F>, I> Func;
+};
+
+template <class R, class P1, class P2, R F(P1, P2), class I,
+          class R2, class P1_2, class P2_2, class P3_2>
+struct ConvertParams<Func2<R, P1, P2, F, I>,
+                     R2 (*)(P1_2, P2_2, P3_2)> {
+  typedef Func3<R, void *, const void *, P3_2,
+                IgnoreHandlerData3<R, P1, P3_2, P2, F>, I> Func;
+};
+
+// For StringBuffer only; this ignores both the handler data and the
+// BufferHandle.
+template <class R, class P1, R F(P1, const char *, size_t), class I, class T>
+struct ConvertParams<Func3<R, P1, const char *, size_t, F, I>, T> {
+  typedef Func5<R, void *, const void *, const char *, size_t,
+                const BufferHandle *, IgnoreHandlerDataIgnoreHandle<R, P1, F>,
+                I> Func;
+};
+
+template <class R, class P1, class P2, class P3, class P4, R F(P1, P2, P3, P4),
+          class I, class T>
+struct ConvertParams<Func4<R, P1, P2, P3, P4, F, I>, T> {
+  typedef Func5<R, void *, const void *, P2, P3, P4,
+                IgnoreHandlerData5<R, P1, P2, P3, P4, F>, I> Func;
+};
+
+// For bound functions, cast the handler data.
+template <class R, class P1, class P2, R F(P1, P2), class I, class T>
+struct ConvertParams<BoundFunc2<R, P1, P2, F, I>, T> {
+  typedef Func2<R, void *, const void *, CastHandlerData2<R, P1, P2, F>, I>
+      Func;
+};
+
+template <class R, class P1, class P2, class P3, R F(P1, P2, P3), class I,
+          class R2, class P1_2, class P2_2, class P3_2>
+struct ConvertParams<BoundFunc3<R, P1, P2, P3, F, I>,
+                     R2 (*)(P1_2, P2_2, P3_2)> {
+  typedef Func3<R, void *, const void *, P3_2,
+                CastHandlerData3<R, P1, P2, P3_2, P3, F>, I> Func;
+};
+
+// For StringBuffer only; this ignores the BufferHandle.
+template <class R, class P1, class P2, R F(P1, P2, const char *, size_t),
+          class I, class T>
+struct ConvertParams<BoundFunc4<R, P1, P2, const char *, size_t, F, I>, T> {
+  typedef Func5<R, void *, const void *, const char *, size_t,
+                const BufferHandle *, CastHandlerDataIgnoreHandle<R, P1, P2, F>,
+                I> Func;
+};
+
+template <class R, class P1, class P2, class P3, class P4, class P5,
+          R F(P1, P2, P3, P4, P5), class I, class T>
+struct ConvertParams<BoundFunc5<R, P1, P2, P3, P4, P5, F, I>, T> {
+  typedef Func5<R, void *, const void *, P3, P4, P5,
+                CastHandlerData5<R, P1, P2, P3, P4, P5, F>, I> Func;
+};
+
+// utype/ltype are upper/lower-case, ctype is canonical C type, vtype is
+// variant C type.
+#define TYPE_METHODS(utype, ltype, ctype, vtype)                               \
+  template <> struct CanonicalType<vtype> {                                    \
+    typedef ctype Type;                                                        \
+  };                                                                           \
+  template <>                                                                  \
+  inline bool Handlers::SetValueHandler<vtype>(                                \
+      const FieldDef *f,                                                       \
+      const Handlers::utype ## Handler& handler) {                             \
+    assert(!handler.registered_);                                              \
+    handler.AddCleanup(this);                                                  \
+    handler.registered_ = true;                                                \
+    return upb_handlers_set##ltype(this, f, handler.handler_, &handler.attr_); \
+  }                                                                            \
+
+TYPE_METHODS(Double, double, double,   double);
+TYPE_METHODS(Float,  float,  float,    float);
+TYPE_METHODS(UInt64, uint64, uint64_t, UPB_UINT64_T);
+TYPE_METHODS(UInt32, uint32, uint32_t, UPB_UINT32_T);
+TYPE_METHODS(Int64,  int64,  int64_t,  UPB_INT64_T);
+TYPE_METHODS(Int32,  int32,  int32_t,  UPB_INT32_T);
+TYPE_METHODS(Bool,   bool,   bool,     bool);
+
+#ifdef UPB_TWO_32BIT_TYPES
+TYPE_METHODS(Int32,  int32,  int32_t,  UPB_INT32ALT_T);
+TYPE_METHODS(UInt32, uint32, uint32_t, UPB_UINT32ALT_T);
+#endif
+
+#ifdef UPB_TWO_64BIT_TYPES
+TYPE_METHODS(Int64,  int64,  int64_t,  UPB_INT64ALT_T);
+TYPE_METHODS(UInt64, uint64, uint64_t, UPB_UINT64ALT_T);
+#endif
+#undef TYPE_METHODS
+
+template <> struct CanonicalType<Status*> {
+  typedef Status* Type;
+};
+
+// Type methods that are only one-per-canonical-type and not one-per-cvariant.
+
+#define TYPE_METHODS(utype, ctype) \
+    inline bool Handlers::Set##utype##Handler(const FieldDef *f, \
+                                              const utype##Handler &h) { \
+      return SetValueHandler<ctype>(f, h); \
+    } \
+
+TYPE_METHODS(Double, double);
+TYPE_METHODS(Float,  float);
+TYPE_METHODS(UInt64, uint64_t);
+TYPE_METHODS(UInt32, uint32_t);
+TYPE_METHODS(Int64,  int64_t);
+TYPE_METHODS(Int32,  int32_t);
+TYPE_METHODS(Bool,   bool);
+#undef TYPE_METHODS
+
+template <class F> struct ReturnOf;
+
+template <class R, class P1, class P2>
+struct ReturnOf<R (*)(P1, P2)> {
+  typedef R Return;
+};
+
+template <class R, class P1, class P2, class P3>
+struct ReturnOf<R (*)(P1, P2, P3)> {
+  typedef R Return;
+};
+
+template <class R, class P1, class P2, class P3, class P4>
+struct ReturnOf<R (*)(P1, P2, P3, P4)> {
+  typedef R Return;
+};
+
+template <class R, class P1, class P2, class P3, class P4, class P5>
+struct ReturnOf<R (*)(P1, P2, P3, P4, P5)> {
+  typedef R Return;
+};
+
+template<class T> const void *UniquePtrForType() {
+  static const char ch = 0;
+  return &ch;
+}
+
+template <class T>
+template <class F>
+inline Handler<T>::Handler(F func)
+    : registered_(false),
+      cleanup_data_(func.GetData()),
+      cleanup_func_(func.GetCleanup()) {
+  upb_handlerattr_sethandlerdata(&attr_, func.GetData());
+  typedef typename ReturnOf<T>::Return Return;
+  typedef typename ConvertParams<F, T>::Func ConvertedParamsFunc;
+  typedef typename MaybeWrapReturn<ConvertedParamsFunc, Return>::Func
+      ReturnWrappedFunc;
+  handler_ = ReturnWrappedFunc().Call;
+
+  // Set attributes based on what templates can statically tell us about the
+  // user's function.
+
+  // If the original function returns void, then we know that we wrapped it to
+  // always return ok.
+  bool always_ok = is_same<typename F::FuncInfo::Return, void>::value;
+  attr_.SetAlwaysOk(always_ok);
+
+  // Closure parameter and return type.
+  attr_.SetClosureType(UniquePtrForType<typename F::FuncInfo::Closure>());
+
+  // We use the closure type (from the first parameter) if the return type is
+  // void.  This is all nonsense for non START* handlers, but it doesn't matter
+  // because in that case the value will be ignored.
+  typedef typename FirstUnlessVoid<typename F::FuncInfo::Return,
+                                   typename F::FuncInfo::Closure>::value
+      EffectiveReturn;
+  attr_.SetReturnClosureType(UniquePtrForType<EffectiveReturn>());
+}
+
+template <class T>
+inline Handler<T>::~Handler() {
+  assert(registered_);
+}
+
+inline HandlerAttributes::HandlerAttributes() { upb_handlerattr_init(this); }
+inline HandlerAttributes::~HandlerAttributes() { upb_handlerattr_uninit(this); }
+inline bool HandlerAttributes::SetHandlerData(const void *hd) {
+  return upb_handlerattr_sethandlerdata(this, hd);
+}
+inline const void* HandlerAttributes::handler_data() const {
+  return upb_handlerattr_handlerdata(this);
+}
+inline bool HandlerAttributes::SetClosureType(const void *type) {
+  return upb_handlerattr_setclosuretype(this, type);
+}
+inline const void* HandlerAttributes::closure_type() const {
+  return upb_handlerattr_closuretype(this);
+}
+inline bool HandlerAttributes::SetReturnClosureType(const void *type) {
+  return upb_handlerattr_setreturnclosuretype(this, type);
+}
+inline const void* HandlerAttributes::return_closure_type() const {
+  return upb_handlerattr_returnclosuretype(this);
+}
+inline bool HandlerAttributes::SetAlwaysOk(bool always_ok) {
+  return upb_handlerattr_setalwaysok(this, always_ok);
+}
+inline bool HandlerAttributes::always_ok() const {
+  return upb_handlerattr_alwaysok(this);
+}
+
+inline BufferHandle::BufferHandle() { upb_bufhandle_init(this); }
+inline BufferHandle::~BufferHandle() { upb_bufhandle_uninit(this); }
+inline const char* BufferHandle::buffer() const {
+  return upb_bufhandle_buf(this);
+}
+inline size_t BufferHandle::object_offset() const {
+  return upb_bufhandle_objofs(this);
+}
+inline void BufferHandle::SetBuffer(const char* buf, size_t ofs) {
+  upb_bufhandle_setbuf(this, buf, ofs);
+}
+template <class T>
+void BufferHandle::SetAttachedObject(const T* obj) {
+  upb_bufhandle_setobj(this, obj, UniquePtrForType<T>());
+}
+template <class T>
+const T* BufferHandle::GetAttachedObject() const {
+  return upb_bufhandle_objtype(this) == UniquePtrForType<T>()
+      ? static_cast<const T *>(upb_bufhandle_obj(this))
+                               : NULL;
+}
+
+inline reffed_ptr<Handlers> Handlers::New(const MessageDef *m) {
+  upb_handlers *h = upb_handlers_new(m, &h);
+  return reffed_ptr<Handlers>(h, &h);
+}
+inline reffed_ptr<const Handlers> Handlers::NewFrozen(
+    const MessageDef *m, upb_handlers_callback *callback,
+    const void *closure) {
+  const upb_handlers *h = upb_handlers_newfrozen(m, &h, callback, closure);
+  return reffed_ptr<const Handlers>(h, &h);
+}
+inline bool Handlers::IsFrozen() const { return upb_handlers_isfrozen(this); }
+inline void Handlers::Ref(const void *owner) const {
+  upb_handlers_ref(this, owner);
+}
+inline void Handlers::Unref(const void *owner) const {
+  upb_handlers_unref(this, owner);
+}
+inline void Handlers::DonateRef(const void *from, const void *to) const {
+  upb_handlers_donateref(this, from, to);
+}
+inline void Handlers::CheckRef(const void *owner) const {
+  upb_handlers_checkref(this, owner);
+}
+inline const Status* Handlers::status() {
+  return upb_handlers_status(this);
+}
+inline void Handlers::ClearError() {
+  return upb_handlers_clearerr(this);
+}
+inline bool Handlers::Freeze(Status *s) {
+  upb::Handlers* h = this;
+  return upb_handlers_freeze(&h, 1, s);
+}
+inline bool Handlers::Freeze(Handlers *const *handlers, int n, Status *s) {
+  return upb_handlers_freeze(handlers, n, s);
+}
+inline bool Handlers::Freeze(const std::vector<Handlers*>& h, Status* status) {
+  return upb_handlers_freeze((Handlers* const*)&h[0], h.size(), status);
+}
+inline const MessageDef *Handlers::message_def() const {
+  return upb_handlers_msgdef(this);
+}
+inline bool Handlers::AddCleanup(void *p, upb_handlerfree *func) {
+  return upb_handlers_addcleanup(this, p, func);
+}
+inline bool Handlers::SetStartMessageHandler(
+    const Handlers::StartMessageHandler &handler) {
+  assert(!handler.registered_);
+  handler.registered_ = true;
+  handler.AddCleanup(this);
+  return upb_handlers_setstartmsg(this, handler.handler_, &handler.attr_);
+}
+inline bool Handlers::SetEndMessageHandler(
+    const Handlers::EndMessageHandler &handler) {
+  assert(!handler.registered_);
+  handler.registered_ = true;
+  handler.AddCleanup(this);
+  return upb_handlers_setendmsg(this, handler.handler_, &handler.attr_);
+}
+inline bool Handlers::SetStartStringHandler(const FieldDef *f,
+                                            const StartStringHandler &handler) {
+  assert(!handler.registered_);
+  handler.registered_ = true;
+  handler.AddCleanup(this);
+  return upb_handlers_setstartstr(this, f, handler.handler_, &handler.attr_);
+}
+inline bool Handlers::SetEndStringHandler(const FieldDef *f,
+                                          const EndFieldHandler &handler) {
+  assert(!handler.registered_);
+  handler.registered_ = true;
+  handler.AddCleanup(this);
+  return upb_handlers_setendstr(this, f, handler.handler_, &handler.attr_);
+}
+inline bool Handlers::SetStringHandler(const FieldDef *f,
+                                       const StringHandler& handler) {
+  assert(!handler.registered_);
+  handler.registered_ = true;
+  handler.AddCleanup(this);
+  return upb_handlers_setstring(this, f, handler.handler_, &handler.attr_);
+}
+inline bool Handlers::SetStartSequenceHandler(
+    const FieldDef *f, const StartFieldHandler &handler) {
+  assert(!handler.registered_);
+  handler.registered_ = true;
+  handler.AddCleanup(this);
+  return upb_handlers_setstartseq(this, f, handler.handler_, &handler.attr_);
+}
+inline bool Handlers::SetStartSubMessageHandler(
+    const FieldDef *f, const StartFieldHandler &handler) {
+  assert(!handler.registered_);
+  handler.registered_ = true;
+  handler.AddCleanup(this);
+  return upb_handlers_setstartsubmsg(this, f, handler.handler_, &handler.attr_);
+}
+inline bool Handlers::SetEndSubMessageHandler(const FieldDef *f,
+                                              const EndFieldHandler &handler) {
+  assert(!handler.registered_);
+  handler.registered_ = true;
+  handler.AddCleanup(this);
+  return upb_handlers_setendsubmsg(this, f, handler.handler_, &handler.attr_);
+}
+inline bool Handlers::SetEndSequenceHandler(const FieldDef *f,
+                                            const EndFieldHandler &handler) {
+  assert(!handler.registered_);
+  handler.registered_ = true;
+  handler.AddCleanup(this);
+  return upb_handlers_setendseq(this, f, handler.handler_, &handler.attr_);
+}
+inline bool Handlers::SetSubHandlers(const FieldDef *f, const Handlers *sub) {
+  return upb_handlers_setsubhandlers(this, f, sub);
+}
+inline const Handlers *Handlers::GetSubHandlers(const FieldDef *f) const {
+  return upb_handlers_getsubhandlers(this, f);
+}
+inline const Handlers *Handlers::GetSubHandlers(Handlers::Selector sel) const {
+  return upb_handlers_getsubhandlers_sel(this, sel);
+}
+inline bool Handlers::GetSelector(const FieldDef *f, Handlers::Type type,
+                                  Handlers::Selector *s) {
+  return upb_handlers_getselector(f, type, s);
+}
+inline Handlers::Selector Handlers::GetEndSelector(Handlers::Selector start) {
+  return upb_handlers_getendselector(start);
+}
+inline Handlers::GenericFunction *Handlers::GetHandler(
+    Handlers::Selector selector) {
+  return upb_handlers_gethandler(this, selector);
+}
+inline const void *Handlers::GetHandlerData(Handlers::Selector selector) {
+  return upb_handlers_gethandlerdata(this, selector);
+}
+
+inline BytesHandler::BytesHandler() {
+  upb_byteshandler_init(this);
+}
+
+inline BytesHandler::~BytesHandler() {
+  upb_byteshandler_uninit(this);
+}
+
+}  // namespace upb
+
+#endif  // __cplusplus
+
+
+#undef UPB_TWO_32BIT_TYPES
+#undef UPB_TWO_64BIT_TYPES
+#undef UPB_INT32_T
+#undef UPB_UINT32_T
+#undef UPB_INT32ALT_T
+#undef UPB_UINT32ALT_T
+#undef UPB_INT64_T
+#undef UPB_UINT64_T
+#undef UPB_INT64ALT_T
+#undef UPB_UINT64ALT_T
+
+#endif  // UPB_HANDLERS_INL_H_
+
+#endif  // UPB_HANDLERS_H
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2010-2012 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * A upb_sink is an object that binds a upb_handlers object to some runtime
+ * state.  It is the object that can actually receive data via the upb_handlers
+ * interface.
+ *
+ * Unlike upb_def and upb_handlers, upb_sink is never frozen, immutable, or
+ * thread-safe.  You can create as many of them as you want, but each one may
+ * only be used in a single thread at a time.
+ *
+ * If we compare with class-based OOP, a you can think of a upb_def as an
+ * abstract base class, a upb_handlers as a concrete derived class, and a
+ * upb_sink as an object (class instance).
+ */
+
+#ifndef UPB_SINK_H
+#define UPB_SINK_H
+
+
+#ifdef __cplusplus
+namespace upb {
+class BufferSource;
+class BytesSink;
+class Sink;
+}
+#endif
+
+UPB_DECLARE_TYPE(upb::BufferSource, upb_bufsrc);
+UPB_DECLARE_TYPE(upb::BytesSink, upb_bytessink);
+UPB_DECLARE_TYPE(upb::Sink, upb_sink);
+
+// Internal-only struct for the sink.
+struct upb_sinkframe {
+ UPB_PRIVATE_FOR_CPP
+  const upb_handlers *h;
+  void *closure;
+
+  // For any frames besides the top, this is the END* callback that will run
+  // when the subframe is popped (for example, for a "sequence" frame the frame
+  // above it will be a UPB_HANDLER_ENDSEQ handler).  But this is only
+  // necessary for assertion checking inside upb_sink and can be omitted if the
+  // sink has only one caller.
+  //
+  // TODO(haberman): have a mechanism for ensuring that a sink only has one
+  // caller.
+  upb_selector_t selector;
+};
+
+// The maximum nesting depth that upb::Sink will allow.  Matches proto2's limit.
+// TODO: make this a runtime-settable property of Sink.
+#define UPB_SINK_MAX_NESTING 64
+
+// A upb::Sink is an object that binds a upb::Handlers object to some runtime
+// state.  It represents an endpoint to which data can be sent.
+//
+// TODO(haberman): right now all of these functions take selectors.  Should they
+// take selectorbase instead?
+//
+// ie. instead of calling:
+//   sink->StartString(FOO_FIELD_START_STRING, ...)
+// a selector base would let you say:
+//   sink->StartString(FOO_FIELD, ...)
+//
+// This would make call sites a little nicer and require emitting fewer selector
+// definitions in .h files.
+//
+// But the current scheme has the benefit that you can retrieve a function
+// pointer for any handler with handlers->GetHandler(selector), without having
+// to have a separate GetHandler() function for each handler type.  The JIT
+// compiler uses this.  To accommodate we'd have to expose a separate
+// GetHandler() for every handler type.
+//
+// Also to ponder: selectors right now are independent of a specific Handlers
+// instance.  In other words, they allocate a number to every possible handler
+// that *could* be registered, without knowing anything about what handlers
+// *are* registered.  That means that using selectors as table offsets prohibits
+// us from compacting the handler table at Freeze() time.  If the table is very
+// sparse, this could be wasteful.
+//
+// Having another selector-like thing that is specific to a Handlers instance
+// would allow this compacting, but then it would be impossible to write code
+// ahead-of-time that can be bound to any Handlers instance at runtime.  For
+// example, a .proto file parser written as straight C will not know what
+// Handlers it will be bound to, so when it calls sink->StartString() what
+// selector will it pass?  It needs a selector like we have today, that is
+// independent of any particular upb::Handlers.
+//
+// Is there a way then to allow Handlers table compaction?
+UPB_DEFINE_CLASS0(upb::Sink,
+ public:
+  // Constructor with no initialization; must be Reset() before use.
+  Sink() {}
+
+  // Constructs a new sink for the given frozen handlers and closure.
+  //
+  // TODO: once the Handlers know the expected closure type, verify that T
+  // matches it.
+  template <class T> Sink(const Handlers* handlers, T* closure);
+
+  // Resets the value of the sink.
+  template <class T> void Reset(const Handlers* handlers, T* closure);
+
+  // Returns the top-level object that is bound to this sink.
+  //
+  // TODO: once the Handlers know the expected closure type, verify that T
+  // matches it.
+  template <class T> T* GetObject() const;
+
+  // Functions for pushing data into the sink.
+  //
+  // These return false if processing should stop (either due to error or just
+  // to suspend).
+  //
+  // These may not be called from within one of the same sink's handlers (in
+  // other words, handlers are not re-entrant).
+
+  // Should be called at the start and end of every message; both the top-level
+  // message and submessages.  This means that submessages should use the
+  // following sequence:
+  //   sink->StartSubMessage(startsubmsg_selector);
+  //   sink->StartMessage();
+  //   // ...
+  //   sink->EndMessage(&status);
+  //   sink->EndSubMessage(endsubmsg_selector);
+  bool StartMessage();
+  bool EndMessage(Status* status);
+
+  // Putting of individual values.  These work for both repeated and
+  // non-repeated fields, but for repeated fields you must wrap them in
+  // calls to StartSequence()/EndSequence().
+  bool PutInt32(Handlers::Selector s, int32_t val);
+  bool PutInt64(Handlers::Selector s, int64_t val);
+  bool PutUInt32(Handlers::Selector s, uint32_t val);
+  bool PutUInt64(Handlers::Selector s, uint64_t val);
+  bool PutFloat(Handlers::Selector s, float val);
+  bool PutDouble(Handlers::Selector s, double val);
+  bool PutBool(Handlers::Selector s, bool val);
+
+  // Putting of string/bytes values.  Each string can consist of zero or more
+  // non-contiguous buffers of data.
+  //
+  // For StartString(), the function will write a sink for the string to "sub."
+  // The sub-sink must be used for any/all PutStringBuffer() calls.
+  bool StartString(Handlers::Selector s, size_t size_hint, Sink* sub);
+  size_t PutStringBuffer(Handlers::Selector s, const char *buf, size_t len,
+                         const BufferHandle *handle);
+  bool EndString(Handlers::Selector s);
+
+  // For submessage fields.
+  //
+  // For StartSubMessage(), the function will write a sink for the string to
+  // "sub." The sub-sink must be used for any/all handlers called within the
+  // submessage.
+  bool StartSubMessage(Handlers::Selector s, Sink* sub);
+  bool EndSubMessage(Handlers::Selector s);
+
+  // For repeated fields of any type, the sequence of values must be wrapped in
+  // these calls.
+  //
+  // For StartSequence(), the function will write a sink for the string to
+  // "sub." The sub-sink must be used for any/all handlers called within the
+  // sequence.
+  bool StartSequence(Handlers::Selector s, Sink* sub);
+  bool EndSequence(Handlers::Selector s);
+
+  // Copy and assign specifically allowed.
+  // We don't even bother making these members private because so many
+  // functions need them and this is mainly just a dumb data container anyway.
+,
+UPB_DEFINE_STRUCT0(upb_sink,
+  const upb_handlers *handlers;
+  void *closure;
+));
+
+UPB_DEFINE_CLASS0(upb::BytesSink,
+ public:
+  BytesSink() {}
+
+  // Constructs a new sink for the given frozen handlers and closure.
+  //
+  // TODO(haberman): once the Handlers know the expected closure type, verify
+  // that T matches it.
+  template <class T> BytesSink(const BytesHandler* handler, T* closure);
+
+  // Resets the value of the sink.
+  template <class T> void Reset(const BytesHandler* handler, T* closure);
+
+  bool Start(size_t size_hint, void **subc);
+  size_t PutBuffer(void *subc, const char *buf, size_t len,
+                   const BufferHandle *handle);
+  bool End();
+,
+UPB_DEFINE_STRUCT0(upb_bytessink,
+  const upb_byteshandler *handler;
+  void *closure;
+));
+
+// A class for pushing a flat buffer of data to a BytesSink.
+// You can construct an instance of this to get a resumable source,
+// or just call the static PutBuffer() to do a non-resumable push all in one go.
+UPB_DEFINE_CLASS0(upb::BufferSource,
+ public:
+  BufferSource();
+  BufferSource(const char* buf, size_t len, BytesSink* sink);
+
+  // Returns true if the entire buffer was pushed successfully.  Otherwise the
+  // next call to PutNext() will resume where the previous one left off.
+  // TODO(haberman): implement this.
+  bool PutNext();
+
+  // A static version; with this version is it not possible to resume in the
+  // case of failure or a partially-consumed buffer.
+  static bool PutBuffer(const char* buf, size_t len, BytesSink* sink);
+
+  template <class T> static bool PutBuffer(const T& str, BytesSink* sink) {
+    return PutBuffer(str.c_str(), str.size(), sink);
+  }
+,
+UPB_DEFINE_STRUCT0(upb_bufsrc,
+));
+
+UPB_BEGIN_EXTERN_C  // {
+
+// Inline definitions.
+
+UPB_INLINE void upb_bytessink_reset(upb_bytessink *s, const upb_byteshandler *h,
+                                    void *closure) {
+  s->handler = h;
+  s->closure = closure;
+}
+
+UPB_INLINE bool upb_bytessink_start(upb_bytessink *s, size_t size_hint,
+                                    void **subc) {
+  *subc = s->closure;
+  if (!s->handler) return true;
+  upb_startstr_handlerfunc *start =
+      (upb_startstr_handlerfunc *)s->handler->table[UPB_STARTSTR_SELECTOR].func;
+
+  if (!start) return true;
+  *subc = start(s->closure, upb_handlerattr_handlerdata(
+                                &s->handler->table[UPB_STARTSTR_SELECTOR].attr),
+                size_hint);
+  return *subc != NULL;
+}
+
+UPB_INLINE size_t upb_bytessink_putbuf(upb_bytessink *s, void *subc,
+                                       const char *buf, size_t size,
+                                       const upb_bufhandle* handle) {
+  if (!s->handler) return true;
+  upb_string_handlerfunc *putbuf =
+      (upb_string_handlerfunc *)s->handler->table[UPB_STRING_SELECTOR].func;
+
+  if (!putbuf) return true;
+  return putbuf(subc, upb_handlerattr_handlerdata(
+                          &s->handler->table[UPB_STRING_SELECTOR].attr),
+                buf, size, handle);
+}
+
+UPB_INLINE bool upb_bytessink_end(upb_bytessink *s) {
+  if (!s->handler) return true;
+  upb_endfield_handlerfunc *end =
+      (upb_endfield_handlerfunc *)s->handler->table[UPB_ENDSTR_SELECTOR].func;
+
+  if (!end) return true;
+  return end(s->closure,
+             upb_handlerattr_handlerdata(
+                 &s->handler->table[UPB_ENDSTR_SELECTOR].attr));
+}
+
+UPB_INLINE bool upb_bufsrc_putbuf(const char *buf, size_t len,
+                                  upb_bytessink *sink) {
+  void *subc;
+  upb_bufhandle handle;
+  upb_bufhandle_init(&handle);
+  upb_bufhandle_setbuf(&handle, buf, 0);
+  bool ret = upb_bytessink_start(sink, len, &subc);
+  if (ret && len != 0) {
+    ret = (upb_bytessink_putbuf(sink, subc, buf, len, &handle) == len);
+  }
+  if (ret) {
+    ret = upb_bytessink_end(sink);
+  }
+  upb_bufhandle_uninit(&handle);
+  return ret;
+}
+
+#define PUTVAL(type, ctype)                                                    \
+  UPB_INLINE bool upb_sink_put##type(upb_sink *s, upb_selector_t sel,          \
+                                     ctype val) {                              \
+    if (!s->handlers) return true;                                             \
+    upb_##type##_handlerfunc *func =                                           \
+        (upb_##type##_handlerfunc *)upb_handlers_gethandler(s->handlers, sel); \
+    if (!func) return true;                                                    \
+    const void *hd = upb_handlers_gethandlerdata(s->handlers, sel);            \
+    return func(s->closure, hd, val);                                          \
+  }
+
+PUTVAL(int32,  int32_t);
+PUTVAL(int64,  int64_t);
+PUTVAL(uint32, uint32_t);
+PUTVAL(uint64, uint64_t);
+PUTVAL(float,  float);
+PUTVAL(double, double);
+PUTVAL(bool,   bool);
+#undef PUTVAL
+
+UPB_INLINE void upb_sink_reset(upb_sink *s, const upb_handlers *h, void *c) {
+  s->handlers = h;
+  s->closure = c;
+}
+
+UPB_INLINE size_t upb_sink_putstring(upb_sink *s, upb_selector_t sel,
+                                     const char *buf, size_t n,
+                                     const upb_bufhandle *handle) {
+  if (!s->handlers) return n;
+  upb_string_handlerfunc *handler =
+      (upb_string_handlerfunc *)upb_handlers_gethandler(s->handlers, sel);
+
+  if (!handler) return n;
+  const void *hd = upb_handlers_gethandlerdata(s->handlers, sel);
+  return handler(s->closure, hd, buf, n, handle);
+}
+
+UPB_INLINE bool upb_sink_startmsg(upb_sink *s) {
+  if (!s->handlers) return true;
+  upb_startmsg_handlerfunc *startmsg =
+      (upb_startmsg_handlerfunc *)upb_handlers_gethandler(s->handlers,
+                                                      UPB_STARTMSG_SELECTOR);
+  if (!startmsg) return true;
+  const void *hd =
+      upb_handlers_gethandlerdata(s->handlers, UPB_STARTMSG_SELECTOR);
+  return startmsg(s->closure, hd);
+}
+
+UPB_INLINE bool upb_sink_endmsg(upb_sink *s, upb_status *status) {
+  if (!s->handlers) return true;
+  upb_endmsg_handlerfunc *endmsg =
+      (upb_endmsg_handlerfunc *)upb_handlers_gethandler(s->handlers,
+                                                        UPB_ENDMSG_SELECTOR);
+
+  if (!endmsg) return true;
+  const void *hd =
+      upb_handlers_gethandlerdata(s->handlers, UPB_ENDMSG_SELECTOR);
+  return endmsg(s->closure, hd, status);
+}
+
+UPB_INLINE bool upb_sink_startseq(upb_sink *s, upb_selector_t sel,
+                                  upb_sink *sub) {
+  sub->closure = s->closure;
+  sub->handlers = s->handlers;
+  if (!s->handlers) return true;
+  upb_startfield_handlerfunc *startseq =
+      (upb_startfield_handlerfunc*)upb_handlers_gethandler(s->handlers, sel);
+
+  if (!startseq) return true;
+  const void *hd = upb_handlers_gethandlerdata(s->handlers, sel);
+  sub->closure = startseq(s->closure, hd);
+  return sub->closure ? true : false;
+}
+
+UPB_INLINE bool upb_sink_endseq(upb_sink *s, upb_selector_t sel) {
+  if (!s->handlers) return true;
+  upb_endfield_handlerfunc *endseq =
+      (upb_endfield_handlerfunc*)upb_handlers_gethandler(s->handlers, sel);
+
+  if (!endseq) return true;
+  const void *hd = upb_handlers_gethandlerdata(s->handlers, sel);
+  return endseq(s->closure, hd);
+}
+
+UPB_INLINE bool upb_sink_startstr(upb_sink *s, upb_selector_t sel,
+                                  size_t size_hint, upb_sink *sub) {
+  sub->closure = s->closure;
+  sub->handlers = s->handlers;
+  if (!s->handlers) return true;
+  upb_startstr_handlerfunc *startstr =
+      (upb_startstr_handlerfunc*)upb_handlers_gethandler(s->handlers, sel);
+
+  if (!startstr) return true;
+  const void *hd = upb_handlers_gethandlerdata(s->handlers, sel);
+  sub->closure = startstr(s->closure, hd, size_hint);
+  return sub->closure ? true : false;
+}
+
+UPB_INLINE bool upb_sink_endstr(upb_sink *s, upb_selector_t sel) {
+  if (!s->handlers) return true;
+  upb_endfield_handlerfunc *endstr =
+      (upb_endfield_handlerfunc*)upb_handlers_gethandler(s->handlers, sel);
+
+  if (!endstr) return true;
+  const void *hd = upb_handlers_gethandlerdata(s->handlers, sel);
+  return endstr(s->closure, hd);
+}
+
+UPB_INLINE bool upb_sink_startsubmsg(upb_sink *s, upb_selector_t sel,
+                                     upb_sink *sub) {
+  sub->closure = s->closure;
+  if (!s->handlers) {
+    sub->handlers = NULL;
+    return true;
+  }
+  sub->handlers = upb_handlers_getsubhandlers_sel(s->handlers, sel);
+  upb_startfield_handlerfunc *startsubmsg =
+      (upb_startfield_handlerfunc*)upb_handlers_gethandler(s->handlers, sel);
+
+  if (!startsubmsg) return true;
+  const void *hd = upb_handlers_gethandlerdata(s->handlers, sel);
+  sub->closure = startsubmsg(s->closure, hd);
+  return sub->closure ? true : false;
+}
+
+UPB_INLINE bool upb_sink_endsubmsg(upb_sink *s, upb_selector_t sel) {
+  if (!s->handlers) return true;
+  upb_endfield_handlerfunc *endsubmsg =
+      (upb_endfield_handlerfunc*)upb_handlers_gethandler(s->handlers, sel);
+
+  if (!endsubmsg) return s->closure;
+  const void *hd = upb_handlers_gethandlerdata(s->handlers, sel);
+  return endsubmsg(s->closure, hd);
+}
+
+UPB_END_EXTERN_C  // }
+
+#ifdef __cplusplus
+
+namespace upb {
+
+template <class T> Sink::Sink(const Handlers* handlers, T* closure) {
+  upb_sink_reset(this, handlers, closure);
+}
+template <class T>
+inline void Sink::Reset(const Handlers* handlers, T* closure) {
+  upb_sink_reset(this, handlers, closure);
+}
+inline bool Sink::StartMessage() {
+  return upb_sink_startmsg(this);
+}
+inline bool Sink::EndMessage(Status* status) {
+  return upb_sink_endmsg(this, status);
+}
+inline bool Sink::PutInt32(Handlers::Selector sel, int32_t val) {
+  return upb_sink_putint32(this, sel, val);
+}
+inline bool Sink::PutInt64(Handlers::Selector sel, int64_t val) {
+  return upb_sink_putint64(this, sel, val);
+}
+inline bool Sink::PutUInt32(Handlers::Selector sel, uint32_t val) {
+  return upb_sink_putuint32(this, sel, val);
+}
+inline bool Sink::PutUInt64(Handlers::Selector sel, uint64_t val) {
+  return upb_sink_putuint64(this, sel, val);
+}
+inline bool Sink::PutFloat(Handlers::Selector sel, float val) {
+  return upb_sink_putfloat(this, sel, val);
+}
+inline bool Sink::PutDouble(Handlers::Selector sel, double val) {
+  return upb_sink_putdouble(this, sel, val);
+}
+inline bool Sink::PutBool(Handlers::Selector sel, bool val) {
+  return upb_sink_putbool(this, sel, val);
+}
+inline bool Sink::StartString(Handlers::Selector sel, size_t size_hint,
+                              Sink *sub) {
+  return upb_sink_startstr(this, sel, size_hint, sub);
+}
+inline size_t Sink::PutStringBuffer(Handlers::Selector sel, const char *buf,
+                                    size_t len, const BufferHandle* handle) {
+  return upb_sink_putstring(this, sel, buf, len, handle);
+}
+inline bool Sink::EndString(Handlers::Selector sel) {
+  return upb_sink_endstr(this, sel);
+}
+inline bool Sink::StartSubMessage(Handlers::Selector sel, Sink* sub) {
+  return upb_sink_startsubmsg(this, sel, sub);
+}
+inline bool Sink::EndSubMessage(Handlers::Selector sel) {
+  return upb_sink_endsubmsg(this, sel);
+}
+inline bool Sink::StartSequence(Handlers::Selector sel, Sink* sub) {
+  return upb_sink_startseq(this, sel, sub);
+}
+inline bool Sink::EndSequence(Handlers::Selector sel) {
+  return upb_sink_endseq(this, sel);
+}
+
+template <class T>
+BytesSink::BytesSink(const BytesHandler* handler, T* closure) {
+  Reset(handler, closure);
+}
+
+template <class T>
+void BytesSink::Reset(const BytesHandler *handler, T *closure) {
+  upb_bytessink_reset(this, handler, closure);
+}
+inline bool BytesSink::Start(size_t size_hint, void **subc) {
+  return upb_bytessink_start(this, size_hint, subc);
+}
+inline size_t BytesSink::PutBuffer(void *subc, const char *buf, size_t len,
+                                   const BufferHandle *handle) {
+  return upb_bytessink_putbuf(this, subc, buf, len, handle);
+}
+inline bool BytesSink::End() {
+  return upb_bytessink_end(this);
+}
+
+inline bool BufferSource::PutBuffer(const char *buf, size_t len,
+                                    BytesSink *sink) {
+  return upb_bufsrc_putbuf(buf, len, sink);
+}
+
+}  // namespace upb
+#endif
+
+#endif
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2013 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * For handlers that do very tiny, very simple operations, the function call
+ * overhead of calling a handler can be significant.  This file allows the
+ * user to define handlers that do something very simple like store the value
+ * to memory and/or set a hasbit.  JIT compilers can then special-case these
+ * handlers and emit specialized code for them instead of actually calling the
+ * handler.
+ *
+ * The functionality is very simple/limited right now but may expand to be able
+ * to call another function.
+ */
+
+#ifndef UPB_SHIM_H
+#define UPB_SHIM_H
+
+
+typedef struct {
+  size_t offset;
+  int32_t hasbit;
+} upb_shim_data;
+
+#ifdef __cplusplus
+
+namespace upb {
+
+struct Shim {
+  typedef upb_shim_data Data;
+
+  // Sets a handler for the given field that writes the value to the given
+  // offset and, if hasbit >= 0, sets a bit at the given bit offset.  Returns
+  // true if the handler was set successfully.
+  static bool Set(Handlers *h, const FieldDef *f, size_t ofs, int32_t hasbit);
+
+  // If this handler is a shim, returns the corresponding upb::Shim::Data and
+  // stores the type in "type".  Otherwise returns NULL.
+  static const Data* GetData(const Handlers* h, Handlers::Selector s,
+                             FieldDef::Type* type);
+};
+
+}  // namespace upb
+
+#endif
+
+UPB_BEGIN_EXTERN_C  // {
+
+// C API.
+bool upb_shim_set(upb_handlers *h, const upb_fielddef *f, size_t offset,
+                  int32_t hasbit);
+const upb_shim_data *upb_shim_getdata(const upb_handlers *h, upb_selector_t s,
+                                      upb_fieldtype_t *type);
+
+UPB_END_EXTERN_C  // }
+
+#ifdef __cplusplus
+// C++ Wrappers.
+namespace upb {
+inline bool Shim::Set(Handlers* h, const FieldDef* f, size_t ofs,
+                      int32_t hasbit) {
+  return upb_shim_set(h, f, ofs, hasbit);
+}
+inline const Shim::Data* Shim::GetData(const Handlers* h, Handlers::Selector s,
+                                       FieldDef::Type* type) {
+  return upb_shim_getdata(h, s, type);
+}
+}  // namespace upb
+#endif
+
+#endif  // UPB_SHIM_H
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2011 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * upb::descriptor::Reader provides a way of building upb::Defs from
+ * data in descriptor.proto format.
+ */
+
+#ifndef UPB_DESCRIPTOR_H
+#define UPB_DESCRIPTOR_H
+
+
+#ifdef __cplusplus
+namespace upb {
+namespace descriptor {
+class Reader;
+}  // namespace descriptor
+}  // namespace upb
+#endif
+
+UPB_DECLARE_TYPE(upb::descriptor::Reader, upb_descreader);
+
+// Internal-only structs used by Reader.
+
+// upb_deflist is an internal-only dynamic array for storing a growing list of
+// upb_defs.
+typedef struct {
+ UPB_PRIVATE_FOR_CPP
+  upb_def **defs;
+  size_t len;
+  size_t size;
+  bool owned;
+} upb_deflist;
+
+// We keep a stack of all the messages scopes we are currently in, as well as
+// the top-level file scope.  This is necessary to correctly qualify the
+// definitions that are contained inside.  "name" tracks the name of the
+// message or package (a bare name -- not qualified by any enclosing scopes).
+typedef struct {
+ UPB_PRIVATE_FOR_CPP
+  char *name;
+  // Index of the first def that is under this scope.  For msgdefs, the
+  // msgdef itself is at start-1.
+  int start;
+} upb_descreader_frame;
+
+// The maximum number of nested declarations that are allowed, ie.
+// message Foo {
+//   message Bar {
+//     message Baz {
+//     }
+//   }
+// }
+//
+// This is a resource limit that affects how big our runtime stack can grow.
+// TODO: make this a runtime-settable property of the Reader instance.
+#define UPB_MAX_MESSAGE_NESTING 64
+
+// Class that receives descriptor data according to the descriptor.proto schema
+// and use it to build upb::Defs corresponding to that schema.
+UPB_DEFINE_CLASS0(upb::descriptor::Reader,
+ public:
+  // These handlers must have come from NewHandlers() and must outlive the
+  // Reader.
+  //
+  // TODO: generate the handlers statically (like we do with the
+  // descriptor.proto defs) so that there is no need to pass this parameter (or
+  // to build/memory-manage the handlers at runtime at all).  Unfortunately this
+  // is a bit tricky to implement for Handlers, but necessary to simplify this
+  // interface.
+  Reader(const Handlers* handlers, Status* status);
+  ~Reader();
+
+  // Resets the reader's state and discards any defs it may have built.
+  void Reset();
+
+  // The reader's input; this is where descriptor.proto data should be sent.
+  Sink* input();
+
+  // Returns an array of all defs that have been parsed, and transfers ownership
+  // of them to "owner".  The number of defs is stored in *n.  Ownership of the
+  // returned array is retained and is invalidated by any other call into
+  // Reader.
+  //
+  // These defs are not frozen or resolved; they are ready to be added to a
+  // symtab.
+  upb::Def** GetDefs(void* owner, int* n);
+
+  // Builds and returns handlers for the reader, owned by "owner."
+  static Handlers* NewHandlers(const void* owner);
+,
+UPB_DEFINE_STRUCT0(upb_descreader,
+  upb_sink sink;
+  upb_deflist defs;
+  upb_descreader_frame stack[UPB_MAX_MESSAGE_NESTING];
+  int stack_len;
+
+  uint32_t number;
+  char *name;
+  bool saw_number;
+  bool saw_name;
+
+  char *default_string;
+
+  upb_fielddef *f;
+));
+
+UPB_BEGIN_EXTERN_C  // {
+
+// C API.
+void upb_descreader_init(upb_descreader *r, const upb_handlers *handlers,
+                         upb_status *status);
+void upb_descreader_uninit(upb_descreader *r);
+void upb_descreader_reset(upb_descreader *r);
+upb_sink *upb_descreader_input(upb_descreader *r);
+upb_def **upb_descreader_getdefs(upb_descreader *r, void *owner, int *n);
+const upb_handlers *upb_descreader_newhandlers(const void *owner);
+
+UPB_END_EXTERN_C  // }
+
+#ifdef __cplusplus
+// C++ implementation details. /////////////////////////////////////////////////
+namespace upb {
+namespace descriptor {
+inline Reader::Reader(const Handlers *h, Status *s) {
+  upb_descreader_init(this, h, s);
+}
+inline Reader::~Reader() { upb_descreader_uninit(this); }
+inline void Reader::Reset() { upb_descreader_reset(this); }
+inline Sink* Reader::input() { return upb_descreader_input(this); }
+inline upb::Def** Reader::GetDefs(void* owner, int* n) {
+  return upb_descreader_getdefs(this, owner, n);
+}
+}  // namespace descriptor
+}  // namespace upb
+#endif
+
+#endif  // UPB_DESCRIPTOR_H
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009-2014 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * Internal-only definitions for the decoder.
+ */
+
+#ifndef UPB_DECODER_INT_H_
+#define UPB_DECODER_INT_H_
+
+#include <stdlib.h>
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009-2014 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * upb::pb::Decoder implements a high performance, streaming, resumable decoder
+ * for the binary protobuf format.
+ *
+ * This interface works the same regardless of what decoder backend is being
+ * used.  A client of this class does not need to know whether decoding is using
+ * a JITted decoder (DynASM, LLVM, etc) or an interpreted decoder.  By default,
+ * it will always use the fastest available decoder.  However, you can call
+ * set_allow_jit(false) to disable any JIT decoder that might be available.
+ * This is primarily useful for testing purposes.
+ */
+
+#ifndef UPB_DECODER_H_
+#define UPB_DECODER_H_
+
+
+#ifdef __cplusplus
+namespace upb {
+namespace pb {
+class CodeCache;
+class Decoder;
+class DecoderMethod;
+class DecoderMethodOptions;
+}  // namespace pb
+}  // namespace upb
+#endif
+
+UPB_DECLARE_TYPE(upb::pb::CodeCache, upb_pbcodecache);
+UPB_DECLARE_TYPE(upb::pb::Decoder, upb_pbdecoder);
+UPB_DECLARE_TYPE(upb::pb::DecoderMethod, upb_pbdecodermethod);
+UPB_DECLARE_TYPE(upb::pb::DecoderMethodOptions, upb_pbdecodermethodopts);
+
+// The maximum that any submessages can be nested.  Matches proto2's limit.
+// This specifies the size of the decoder's statically-sized array and therefore
+// setting it high will cause the upb::pb::Decoder object to be larger.
+//
+// If necessary we can add a runtime-settable property to Decoder that allow
+// this to be larger than the compile-time setting, but this would add
+// complexity, particularly since we would have to decide how/if to give users
+// the ability to set a custom memory allocation function.
+#define UPB_DECODER_MAX_NESTING 64
+
+// Internal-only struct used by the decoder.
+typedef struct {
+ UPB_PRIVATE_FOR_CPP
+  // Space optimization note: we store two pointers here that the JIT
+  // doesn't need at all; the upb_handlers* inside the sink and
+  // the dispatch table pointer.  We can optimze so that the JIT uses
+  // smaller stack frames than the interpreter.  The only thing we need
+  // to guarantee is that the fallback routines can find end_ofs.
+  upb_sink sink;
+
+  // The absolute stream offset of the end-of-frame delimiter.
+  // Non-delimited frames (groups and non-packed repeated fields) reuse the
+  // delimiter of their parent, even though the frame may not end there.
+  //
+  // NOTE: the JIT stores a slightly different value here for non-top frames.
+  // It stores the value relative to the end of the enclosed message.  But the
+  // top frame is still stored the same way, which is important for ensuring
+  // that calls from the JIT into C work correctly.
+  uint64_t end_ofs;
+  const uint32_t *base;
+
+  // 0 indicates a length-delimited field.
+  // A positive number indicates a known group.
+  // A negative number indicates an unknown group.
+  int32_t groupnum;
+  upb_inttable *dispatch;  // Not used by the JIT.
+} upb_pbdecoder_frame;
+
+// The parameters one uses to construct a DecoderMethod.
+// TODO(haberman): move allowjit here?  Seems more convenient for users.
+UPB_DEFINE_CLASS0(upb::pb::DecoderMethodOptions,
+ public:
+  // Parameter represents the destination handlers that this method will push
+  // to.
+  explicit DecoderMethodOptions(const Handlers* dest_handlers);
+
+  // Should the decoder push submessages to lazy handlers for fields that have
+  // them?  The caller should set this iff the lazy handlers expect data that is
+  // in protobuf binary format and the caller wishes to lazy parse it.
+  void set_lazy(bool lazy);
+,
+UPB_DEFINE_STRUCT0(upb_pbdecodermethodopts,
+  const upb_handlers *handlers;
+  bool lazy;
+));
+
+// Represents the code to parse a protobuf according to a destination Handlers.
+UPB_DEFINE_CLASS1(upb::pb::DecoderMethod, upb::RefCounted,
+ public:
+  // From upb::ReferenceCounted.
+  void Ref(const void* owner) const;
+  void Unref(const void* owner) const;
+  void DonateRef(const void* from, const void* to) const;
+  void CheckRef(const void* owner) const;
+
+  // The destination handlers that are statically bound to this method.
+  // This method is only capable of outputting to a sink that uses these
+  // handlers.
+  const Handlers* dest_handlers() const;
+
+  // The input handlers for this decoder method.
+  const BytesHandler* input_handler() const;
+
+  // Whether this method is native.
+  bool is_native() const;
+
+  // Convenience method for generating a DecoderMethod without explicitly
+  // creating a CodeCache.
+  static reffed_ptr<const DecoderMethod> New(const DecoderMethodOptions& opts);
+
+ private:
+  UPB_DISALLOW_POD_OPS(DecoderMethod, upb::pb::DecoderMethod);
+,
+UPB_DEFINE_STRUCT(upb_pbdecodermethod, upb_refcounted,
+  // While compiling, the base is relative in "ofs", after compiling it is
+  // absolute in "ptr".
+  union {
+    uint32_t ofs;     // PC offset of method.
+    void *ptr;        // Pointer to bytecode or machine code for this method.
+  } code_base;
+
+  // The decoder method group to which this method belongs.  We own a ref.
+  // Owning a ref on the entire group is more coarse-grained than is strictly
+  // necessary; all we truly require is that methods we directly reference
+  // outlive us, while the group could contain many other messages we don't
+  // require.  But the group represents the messages that were
+  // allocated+compiled together, so it makes the most sense to free them
+  // together also.
+  const upb_refcounted *group;
+
+  // Whether this method is native code or bytecode.
+  bool is_native_;
+
+  // The handler one calls to invoke this method.
+  upb_byteshandler input_handler_;
+
+  // The destination handlers this method is bound to.  We own a ref.
+  const upb_handlers *dest_handlers_;
+
+  // Dispatch table -- used by both bytecode decoder and JIT when encountering a
+  // field number that wasn't the one we were expecting to see.  See
+  // decoder.int.h for the layout of this table.
+  upb_inttable dispatch;
+));
+
+// A Decoder receives binary protobuf data on its input sink and pushes the
+// decoded data to its output sink.
+UPB_DEFINE_CLASS0(upb::pb::Decoder,
+ public:
+  // Constructs a decoder instance for the given method, which must outlive this
+  // decoder.  Any errors during parsing will be set on the given status, which
+  // must also outlive this decoder.
+  Decoder(const DecoderMethod* method, Status* status);
+  ~Decoder();
+
+  // Returns the DecoderMethod this decoder is parsing from.
+  // TODO(haberman): Do users need to be able to rebind this?
+  const DecoderMethod* method() const;
+
+  // Resets the state of the decoder.
+  void Reset();
+
+  // Returns number of bytes successfully parsed.
+  //
+  // This can be useful for determining the stream position where an error
+  // occurred.
+  //
+  // This value may not be up-to-date when called from inside a parsing
+  // callback.
+  uint64_t BytesParsed() const;
+
+  // Resets the output sink of the Decoder.
+  // The given sink must match method()->dest_handlers().
+  //
+  // This must be called at least once before the decoder can be used.  It may
+  // only be called with the decoder is in a state where it was just created or
+  // reset with pipeline.Reset().  The given sink must be from the same pipeline
+  // as this decoder.
+  bool ResetOutput(Sink* sink);
+
+  // The sink on which this decoder receives input.
+  BytesSink* input();
+
+ private:
+  UPB_DISALLOW_COPY_AND_ASSIGN(Decoder);
+,
+UPB_DEFINE_STRUCT0(upb_pbdecoder, UPB_QUOTE(
+  // Our input sink.
+  upb_bytessink input_;
+
+  // The decoder method we are parsing with (owned).
+  const upb_pbdecodermethod *method_;
+
+  size_t call_len;
+  const uint32_t *pc, *last;
+
+  // Current input buffer and its stream offset.
+  const char *buf, *ptr, *end, *checkpoint;
+
+  // End of the delimited region, relative to ptr, or NULL if not in this buf.
+  const char *delim_end;
+
+  // End of the delimited region, relative to ptr, or end if not in this buf.
+  const char *data_end;
+
+  // Overall stream offset of "buf."
+  uint64_t bufstart_ofs;
+
+  // Buffer for residual bytes not parsed from the previous buffer.
+  // The maximum number of residual bytes we require is 12; a five-byte
+  // unknown tag plus an eight-byte value, less one because the value
+  // is only a partial value.
+  char residual[12];
+  char *residual_end;
+
+  // Stores the user buffer passed to our decode function.
+  const char *buf_param;
+  size_t size_param;
+  const upb_bufhandle *handle;
+
+#ifdef UPB_USE_JIT_X64
+  // Used momentarily by the generated code to store a value while a user
+  // function is called.
+  uint32_t tmp_len;
+
+  const void *saved_rsp;
+#endif
+
+  upb_status *status;
+
+  // Our internal stack.
+  upb_pbdecoder_frame *top, *limit;
+  upb_pbdecoder_frame stack[UPB_DECODER_MAX_NESTING];
+#ifdef UPB_USE_JIT_X64
+  // Each native stack frame needs two pointers, plus we need a few frames for
+  // the enter/exit trampolines.
+  const uint32_t *callstack[(UPB_DECODER_MAX_NESTING * 2) + 10];
+#else
+  const uint32_t *callstack[UPB_DECODER_MAX_NESTING];
+#endif
+)));
+
+// A class for caching protobuf processing code, whether bytecode for the
+// interpreted decoder or machine code for the JIT.
+//
+// This class is not thread-safe.
+UPB_DEFINE_CLASS0(upb::pb::CodeCache,
+ public:
+  CodeCache();
+  ~CodeCache();
+
+  // Whether the cache is allowed to generate machine code.  Defaults to true.
+  // There is no real reason to turn it off except for testing or if you are
+  // having a specific problem with the JIT.
+  //
+  // Note that allow_jit = true does not *guarantee* that the code will be JIT
+  // compiled.  If this platform is not supported or the JIT was not compiled
+  // in, the code may still be interpreted.
+  bool allow_jit() const;
+
+  // This may only be called when the object is first constructed, and prior to
+  // any code generation, otherwise returns false and does nothing.
+  bool set_allow_jit(bool allow);
+
+  // Returns a DecoderMethod that can push data to the given handlers.
+  // If a suitable method already exists, it will be returned from the cache.
+  //
+  // Specifying the destination handlers here allows the DecoderMethod to be
+  // statically bound to the destination handlers if possible, which can allow
+  // more efficient decoding.  However the returned method may or may not
+  // actually be statically bound.  But in all cases, the returned method can
+  // push data to the given handlers.
+  const DecoderMethod *GetDecoderMethod(const DecoderMethodOptions& opts);
+
+  // If/when someone needs to explicitly create a dynamically-bound
+  // DecoderMethod*, we can add a method to get it here.
+
+ private:
+  UPB_DISALLOW_COPY_AND_ASSIGN(CodeCache);
+,
+UPB_DEFINE_STRUCT0(upb_pbcodecache,
+  bool allow_jit_;
+
+  // Array of mgroups.
+  upb_inttable groups;
+));
+
+UPB_BEGIN_EXTERN_C  // {
+
+void upb_pbdecoder_init(upb_pbdecoder *d, const upb_pbdecodermethod *method,
+                        upb_status *status);
+void upb_pbdecoder_uninit(upb_pbdecoder *d);
+void upb_pbdecoder_reset(upb_pbdecoder *d);
+const upb_pbdecodermethod *upb_pbdecoder_method(const upb_pbdecoder *d);
+bool upb_pbdecoder_resetoutput(upb_pbdecoder *d, upb_sink *sink);
+upb_bytessink *upb_pbdecoder_input(upb_pbdecoder *d);
+uint64_t upb_pbdecoder_bytesparsed(const upb_pbdecoder *d);
+
+void upb_pbdecodermethodopts_init(upb_pbdecodermethodopts *opts,
+                                  const upb_handlers *h);
+void upb_pbdecodermethodopts_setlazy(upb_pbdecodermethodopts *opts, bool lazy);
+
+void upb_pbdecodermethod_ref(const upb_pbdecodermethod *m, const void *owner);
+void upb_pbdecodermethod_unref(const upb_pbdecodermethod *m, const void *owner);
+void upb_pbdecodermethod_donateref(const upb_pbdecodermethod *m,
+                                   const void *from, const void *to);
+void upb_pbdecodermethod_checkref(const upb_pbdecodermethod *m,
+                                  const void *owner);
+const upb_handlers *upb_pbdecodermethod_desthandlers(
+    const upb_pbdecodermethod *m);
+const upb_byteshandler *upb_pbdecodermethod_inputhandler(
+    const upb_pbdecodermethod *m);
+bool upb_pbdecodermethod_isnative(const upb_pbdecodermethod *m);
+const upb_pbdecodermethod *upb_pbdecodermethod_new(
+    const upb_pbdecodermethodopts *opts, const void *owner);
+
+void upb_pbcodecache_init(upb_pbcodecache *c);
+void upb_pbcodecache_uninit(upb_pbcodecache *c);
+bool upb_pbcodecache_allowjit(const upb_pbcodecache *c);
+bool upb_pbcodecache_setallowjit(upb_pbcodecache *c, bool allow);
+const upb_pbdecodermethod *upb_pbcodecache_getdecodermethod(
+    upb_pbcodecache *c, const upb_pbdecodermethodopts *opts);
+
+UPB_END_EXTERN_C  // }
+
+#ifdef __cplusplus
+
+namespace upb {
+
+namespace pb {
+
+inline Decoder::Decoder(const DecoderMethod* m, Status* s) {
+  upb_pbdecoder_init(this, m, s);
+}
+inline Decoder::~Decoder() {
+  upb_pbdecoder_uninit(this);
+}
+inline const DecoderMethod* Decoder::method() const {
+  return upb_pbdecoder_method(this);
+}
+inline void Decoder::Reset() {
+  upb_pbdecoder_reset(this);
+}
+inline uint64_t Decoder::BytesParsed() const {
+  return upb_pbdecoder_bytesparsed(this);
+}
+inline bool Decoder::ResetOutput(Sink* sink) {
+  return upb_pbdecoder_resetoutput(this, sink);
+}
+inline BytesSink* Decoder::input() {
+  return upb_pbdecoder_input(this);
+}
+
+inline DecoderMethodOptions::DecoderMethodOptions(const Handlers* h) {
+  upb_pbdecodermethodopts_init(this, h);
+}
+inline void DecoderMethodOptions::set_lazy(bool lazy) {
+  upb_pbdecodermethodopts_setlazy(this, lazy);
+}
+
+inline void DecoderMethod::Ref(const void *owner) const {
+  upb_pbdecodermethod_ref(this, owner);
+}
+inline void DecoderMethod::Unref(const void *owner) const {
+  upb_pbdecodermethod_unref(this, owner);
+}
+inline void DecoderMethod::DonateRef(const void *from, const void *to) const {
+  upb_pbdecodermethod_donateref(this, from, to);
+}
+inline void DecoderMethod::CheckRef(const void *owner) const {
+  upb_pbdecodermethod_checkref(this, owner);
+}
+inline const Handlers* DecoderMethod::dest_handlers() const {
+  return upb_pbdecodermethod_desthandlers(this);
+}
+inline const BytesHandler* DecoderMethod::input_handler() const {
+  return upb_pbdecodermethod_inputhandler(this);
+}
+inline bool DecoderMethod::is_native() const {
+  return upb_pbdecodermethod_isnative(this);
+}
+// static
+inline reffed_ptr<const DecoderMethod> DecoderMethod::New(
+    const DecoderMethodOptions &opts) {
+  const upb_pbdecodermethod *m = upb_pbdecodermethod_new(&opts, &m);
+  return reffed_ptr<const DecoderMethod>(m, &m);
+}
+
+inline CodeCache::CodeCache() {
+  upb_pbcodecache_init(this);
+}
+inline CodeCache::~CodeCache() {
+  upb_pbcodecache_uninit(this);
+}
+inline bool CodeCache::allow_jit() const {
+  return upb_pbcodecache_allowjit(this);
+}
+inline bool CodeCache::set_allow_jit(bool allow) {
+  return upb_pbcodecache_setallowjit(this, allow);
+}
+inline const DecoderMethod *CodeCache::GetDecoderMethod(
+    const DecoderMethodOptions& opts) {
+  return upb_pbcodecache_getdecodermethod(this, &opts);
+}
+
+}  // namespace pb
+}  // namespace upb
+
+#endif  // __cplusplus
+
+#endif  /* UPB_DECODER_H_ */
+
+// Opcode definitions.  The canonical meaning of each opcode is its
+// implementation in the interpreter (the JIT is written to match this).
+//
+// All instructions have the opcode in the low byte.
+// Instruction format for most instructions is:
+//
+// +-------------------+--------+
+// |     arg (24)      | op (8) |
+// +-------------------+--------+
+//
+// Exceptions are indicated below.  A few opcodes are multi-word.
+typedef enum {
+  // Opcodes 1-8, 13, 15-18 parse their respective descriptor types.
+  // Arg for all of these is the upb selector for this field.
+#define T(type) OP_PARSE_ ## type = UPB_DESCRIPTOR_TYPE_ ## type
+  T(DOUBLE), T(FLOAT), T(INT64), T(UINT64), T(INT32), T(FIXED64), T(FIXED32),
+  T(BOOL), T(UINT32), T(SFIXED32), T(SFIXED64), T(SINT32), T(SINT64),
+#undef T
+  OP_STARTMSG       = 9,   // No arg.
+  OP_ENDMSG         = 10,  // No arg.
+  OP_STARTSEQ       = 11,
+  OP_ENDSEQ         = 12,
+  OP_STARTSUBMSG    = 14,
+  OP_ENDSUBMSG      = 19,
+  OP_STARTSTR       = 20,
+  OP_STRING         = 21,
+  OP_ENDSTR         = 22,
+
+  OP_PUSHTAGDELIM   = 23,  // No arg.
+  OP_PUSHLENDELIM   = 24,  // No arg.
+  OP_POP            = 25,  // No arg.
+  OP_SETDELIM       = 26,  // No arg.
+  OP_SETBIGGROUPNUM = 27,  // two words: | unused (24) | opc || groupnum (32) |
+  OP_CHECKDELIM     = 28,
+  OP_CALL           = 29,
+  OP_RET            = 30,
+  OP_BRANCH         = 31,
+
+  // Different opcodes depending on how many bytes expected.
+  OP_TAG1           = 32,  // | expected tag (16) | jump target (8) | opc (8) |
+  OP_TAG2           = 33,  // | expected tag (16) | jump target (8) | opc (8) |
+  OP_TAGN           = 34,  // three words:
+                           //   | unused (16) | jump target(8) | opc (8) |
+                           //   |           expected tag 1 (32)          |
+                           //   |           expected tag 2 (32)          |
+
+  OP_SETDISPATCH    = 35,  // N words:
+                           //   | unused (24)         | opc |
+                           //   | upb_inttable* (32 or 64)  |
+
+  OP_HALT           = 36,  // No arg.
+} opcode;
+
+#define OP_MAX OP_HALT
+
+UPB_INLINE opcode getop(uint32_t instr) { return instr & 0xff; }
+
+// Method group; represents a set of decoder methods that had their code
+// emitted together, and must therefore be freed together.  Immutable once
+// created.  It is possible we may want to expose this to users at some point.
+//
+// Overall ownership of Decoder objects looks like this:
+//
+//                +----------+
+//                |          | <---> DecoderMethod
+//                | method   |
+// CodeCache ---> |  group   | <---> DecoderMethod
+//                |          |
+//                | (mgroup) | <---> DecoderMethod
+//                +----------+
+typedef struct {
+  upb_refcounted base;
+
+  // Maps upb_msgdef/upb_handlers -> upb_pbdecodermethod.  We own refs on the
+  // methods.
+  upb_inttable methods;
+
+  // When we add the ability to link to previously existing mgroups, we'll
+  // need an array of mgroups we reference here, and own refs on them.
+
+  // The bytecode for our methods, if any exists.  Owned by us.
+  uint32_t *bytecode;
+  uint32_t *bytecode_end;
+
+#ifdef UPB_USE_JIT_X64
+  // JIT-generated machine code, if any.
+  upb_string_handlerfunc *jit_code;
+  // The size of the jit_code (required to munmap()).
+  size_t jit_size;
+  char *debug_info;
+  void *dl;
+#endif
+} mgroup;
+
+// Decoder entry points; used as handlers.
+void *upb_pbdecoder_startbc(void *closure, const void *pc, size_t size_hint);
+void *upb_pbdecoder_startjit(void *closure, const void *hd, size_t size_hint);
+size_t upb_pbdecoder_decode(void *closure, const void *hd, const char *buf,
+                            size_t size, const upb_bufhandle *handle);
+bool upb_pbdecoder_end(void *closure, const void *handler_data);
+
+// Decoder-internal functions that the JIT calls to handle fallback paths.
+int32_t upb_pbdecoder_resume(upb_pbdecoder *d, void *p, const char *buf,
+                             size_t size, const upb_bufhandle *handle);
+size_t upb_pbdecoder_suspend(upb_pbdecoder *d);
+int32_t upb_pbdecoder_skipunknown(upb_pbdecoder *d, int32_t fieldnum,
+                                  uint8_t wire_type);
+int32_t upb_pbdecoder_checktag_slow(upb_pbdecoder *d, uint64_t expected);
+int32_t upb_pbdecoder_decode_varint_slow(upb_pbdecoder *d, uint64_t *u64);
+int32_t upb_pbdecoder_decode_f32(upb_pbdecoder *d, uint32_t *u32);
+int32_t upb_pbdecoder_decode_f64(upb_pbdecoder *d, uint64_t *u64);
+void upb_pbdecoder_seterr(upb_pbdecoder *d, const char *msg);
+
+// Error messages that are shared between the bytecode and JIT decoders.
+extern const char *kPbDecoderStackOverflow;
+
+// Access to decoderplan members needed by the decoder.
+const char *upb_pbdecoder_getopname(unsigned int op);
+
+// JIT codegen entry point.
+void upb_pbdecoder_jit(mgroup *group);
+void upb_pbdecoder_freejit(mgroup *group);
+
+// A special label that means "do field dispatch for this message and branch to
+// wherever that takes you."
+#define LABEL_DISPATCH 0
+
+// A special slot in the dispatch table that stores the epilogue (ENDMSG and/or
+// RET) for branching to when we find an appropriate ENDGROUP tag.
+#define DISPATCH_ENDMSG 0
+
+// It's important to use this invalid wire type instead of 0 (which is a valid
+// wire type).
+#define NO_WIRE_TYPE 0xff
+
+// The dispatch table layout is:
+//   [field number] -> [ 48-bit offset ][ 8-bit wt2 ][ 8-bit wt1 ]
+//
+// If wt1 matches, jump to the 48-bit offset.  If wt2 matches, lookup
+// (UPB_MAX_FIELDNUMBER + fieldnum) and jump there.
+//
+// We need two wire types because of packed/non-packed compatibility.  A
+// primitive repeated field can use either wire type and be valid.  While we
+// could key the table on fieldnum+wiretype, the table would be 8x sparser.
+//
+// Storing two wire types in the primary value allows us to quickly rule out
+// the second wire type without needing to do a separate lookup (this case is
+// less common than an unknown field).
+UPB_INLINE uint64_t upb_pbdecoder_packdispatch(uint64_t ofs, uint8_t wt1,
+                                               uint8_t wt2) {
+  return (ofs << 16) | (wt2 << 8) | wt1;
+}
+
+UPB_INLINE void upb_pbdecoder_unpackdispatch(uint64_t dispatch, uint64_t *ofs,
+                                             uint8_t *wt1, uint8_t *wt2) {
+  *wt1 = (uint8_t)dispatch;
+  *wt2 = (uint8_t)(dispatch >> 8);
+  *ofs = dispatch >> 16;
+}
+
+// All of the functions in decoder.c that return int32_t return values according
+// to the following scheme:
+//   1. negative values indicate a return code from the following list.
+//   2. positive values indicate that error or end of buffer was hit, and
+//      that the decode function should immediately return the given value
+//      (the decoder state has already been suspended and is ready to be
+//      resumed).
+#define DECODE_OK -1
+#define DECODE_MISMATCH -2  // Used only from checktag_slow().
+#define DECODE_ENDGROUP -3  // Used only from checkunknown().
+
+#define CHECK_RETURN(x) { int32_t ret = x; if (ret >= 0) return ret; }
+
+#endif  // UPB_DECODER_INT_H_
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2011 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * A number of routines for varint manipulation (we keep them all around to
+ * have multiple approaches available for benchmarking).
+ */
+
+#ifndef UPB_VARINT_DECODER_H_
+#define UPB_VARINT_DECODER_H_
+
+#include <assert.h>
+#include <stdint.h>
+#include <string.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// A list of types as they are encoded on-the-wire.
+typedef enum {
+  UPB_WIRE_TYPE_VARINT      = 0,
+  UPB_WIRE_TYPE_64BIT       = 1,
+  UPB_WIRE_TYPE_DELIMITED   = 2,
+  UPB_WIRE_TYPE_START_GROUP = 3,
+  UPB_WIRE_TYPE_END_GROUP   = 4,
+  UPB_WIRE_TYPE_32BIT       = 5,
+} upb_wiretype_t;
+
+#define UPB_MAX_WIRE_TYPE 5
+
+// The maximum number of bytes that it takes to encode a 64-bit varint.
+// Note that with a better encoding this could be 9 (TODO: write up a
+// wiki document about this).
+#define UPB_PB_VARINT_MAX_LEN 10
+
+// Array of the "native" (ie. non-packed-repeated) wire type for the given a
+// descriptor type (upb_descriptortype_t).
+extern const uint8_t upb_pb_native_wire_types[];
+
+/* Zig-zag encoding/decoding **************************************************/
+
+UPB_INLINE int32_t upb_zzdec_32(uint32_t n) {
+  return (n >> 1) ^ -(int32_t)(n & 1);
+}
+UPB_INLINE int64_t upb_zzdec_64(uint64_t n) {
+  return (n >> 1) ^ -(int64_t)(n & 1);
+}
+UPB_INLINE uint32_t upb_zzenc_32(int32_t n) { return (n << 1) ^ (n >> 31); }
+UPB_INLINE uint64_t upb_zzenc_64(int64_t n) { return (n << 1) ^ (n >> 63); }
+
+/* Decoding *******************************************************************/
+
+// All decoding functions return this struct by value.
+typedef struct {
+  const char *p;  // NULL if the varint was unterminated.
+  uint64_t val;
+} upb_decoderet;
+
+// Four functions for decoding a varint of at most eight bytes.  They are all
+// functionally identical, but are implemented in different ways and likely have
+// different performance profiles.  We keep them around for performance testing.
+//
+// Note that these functions may not read byte-by-byte, so they must not be used
+// unless there are at least eight bytes left in the buffer!
+upb_decoderet upb_vdecode_max8_branch32(upb_decoderet r);
+upb_decoderet upb_vdecode_max8_branch64(upb_decoderet r);
+upb_decoderet upb_vdecode_max8_wright(upb_decoderet r);
+upb_decoderet upb_vdecode_max8_massimino(upb_decoderet r);
+
+// Template for a function that checks the first two bytes with branching
+// and dispatches 2-10 bytes with a separate function.  Note that this may read
+// up to 10 bytes, so it must not be used unless there are at least ten bytes
+// left in the buffer!
+#define UPB_VARINT_DECODER_CHECK2(name, decode_max8_function)                  \
+UPB_INLINE upb_decoderet upb_vdecode_check2_ ## name(const char *_p) {         \
+  uint8_t *p = (uint8_t*)_p;                                                   \
+  if ((*p & 0x80) == 0) { upb_decoderet r = {_p + 1, *p & 0x7fU}; return r; }  \
+  upb_decoderet r = {_p + 2, (*p & 0x7fU) | ((*(p + 1) & 0x7fU) << 7)};        \
+  if ((*(p + 1) & 0x80) == 0) return r;                                        \
+  return decode_max8_function(r);                                              \
+}
+
+UPB_VARINT_DECODER_CHECK2(branch32, upb_vdecode_max8_branch32);
+UPB_VARINT_DECODER_CHECK2(branch64, upb_vdecode_max8_branch64);
+UPB_VARINT_DECODER_CHECK2(wright, upb_vdecode_max8_wright);
+UPB_VARINT_DECODER_CHECK2(massimino, upb_vdecode_max8_massimino);
+#undef UPB_VARINT_DECODER_CHECK2
+
+// Our canonical functions for decoding varints, based on the currently
+// favored best-performing implementations.
+UPB_INLINE upb_decoderet upb_vdecode_fast(const char *p) {
+  if (sizeof(long) == 8)
+    return upb_vdecode_check2_branch64(p);
+  else
+    return upb_vdecode_check2_branch32(p);
+}
+
+UPB_INLINE upb_decoderet upb_vdecode_max8_fast(upb_decoderet r) {
+  return upb_vdecode_max8_massimino(r);
+}
+
+
+/* Encoding *******************************************************************/
+
+UPB_INLINE int upb_value_size(uint64_t val) {
+#ifdef __GNUC__
+  int high_bit = 63 - __builtin_clzll(val);  // 0-based, undef if val == 0.
+#else
+  int high_bit = 0;
+  uint64_t tmp = val;
+  while(tmp >>= 1) high_bit++;
+#endif
+  return val == 0 ? 1 : high_bit / 8 + 1;
+}
+
+// Encodes a 64-bit varint into buf (which must be >=UPB_PB_VARINT_MAX_LEN
+// bytes long), returning how many bytes were used.
+//
+// TODO: benchmark and optimize if necessary.
+UPB_INLINE size_t upb_vencode64(uint64_t val, char *buf) {
+  if (val == 0) { buf[0] = 0; return 1; }
+  size_t i = 0;
+  while (val) {
+    uint8_t byte = val & 0x7fU;
+    val >>= 7;
+    if (val) byte |= 0x80U;
+    buf[i++] = byte;
+  }
+  return i;
+}
+
+UPB_INLINE size_t upb_varint_size(uint64_t val) {
+  char buf[UPB_PB_VARINT_MAX_LEN];
+  return upb_vencode64(val, buf);
+}
+
+// Encodes a 32-bit varint, *not* sign-extended.
+UPB_INLINE uint64_t upb_vencode32(uint32_t val) {
+  char buf[UPB_PB_VARINT_MAX_LEN];
+  size_t bytes = upb_vencode64(val, buf);
+  uint64_t ret = 0;
+  assert(bytes <= 5);
+  memcpy(&ret, buf, bytes);
+  assert(ret <= 0xffffffffffU);
+  return ret;
+}
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif  /* UPB_VARINT_DECODER_H_ */
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009-2010 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * Implements a set of upb_handlers that write protobuf data to the binary wire
+ * format.
+ *
+ * This encoder implementation does not have any access to any out-of-band or
+ * precomputed lengths for submessages, so it must buffer submessages internally
+ * before it can emit the first byte.
+ */
+
+#ifndef UPB_ENCODER_H_
+#define UPB_ENCODER_H_
+
+
+#ifdef __cplusplus
+namespace upb {
+namespace pb {
+class Encoder;
+}  // namespace pb
+}  // namespace upb
+#endif
+
+UPB_DECLARE_TYPE(upb::pb::Encoder, upb_pb_encoder);
+
+#define UPB_PBENCODER_MAX_NESTING 100
+
+/* upb::pb::Encoder ***********************************************************/
+
+// The output buffer is divided into segments; a segment is a string of data
+// that is "ready to go" -- it does not need any varint lengths inserted into
+// the middle.  The seams between segments are where varints will be inserted
+// once they are known.
+//
+// We also use the concept of a "run", which is a range of encoded bytes that
+// occur at a single submessage level.  Every segment contains one or more runs.
+//
+// A segment can span messages.  Consider:
+//
+//                  .--Submessage lengths---------.
+//                  |       |                     |
+//                  |       V                     V
+//                  V      | |---------------    | |-----------------
+// Submessages:    | |-----------------------------------------------
+// Top-level msg: ------------------------------------------------------------
+//
+// Segments:          -----   -------------------   -----------------
+// Runs:              *----   *--------------*---   *----------------
+// (* marks the start)
+//
+// Note that the top-level menssage is not in any segment because it does not
+// have any length preceding it.
+//
+// A segment is only interrupted when another length needs to be inserted.  So
+// observe how the second segment spans both the inner submessage and part of
+// the next enclosing message.
+typedef struct {
+ UPB_PRIVATE_FOR_CPP
+  uint32_t msglen;  // The length to varint-encode before this segment.
+  uint32_t seglen;  // Length of the segment.
+} upb_pb_encoder_segment;
+
+UPB_DEFINE_CLASS0(upb::pb::Encoder,
+ public:
+  Encoder(const upb::Handlers* handlers);
+  ~Encoder();
+
+  static reffed_ptr<const Handlers> NewHandlers(const upb::MessageDef* msg);
+
+  // Resets the state of the printer, so that it will expect to begin a new
+  // document.
+  void Reset();
+
+  // Resets the output pointer which will serve as our closure.
+  void ResetOutput(BytesSink* output);
+
+  // The input to the encoder.
+  Sink* input();
+
+ private:
+  UPB_DISALLOW_COPY_AND_ASSIGN(Encoder);
+,
+UPB_DEFINE_STRUCT0(upb_pb_encoder, UPB_QUOTE(
+  // Our input and output.
+  upb_sink input_;
+  upb_bytessink *output_;
+
+  // The "subclosure" -- used as the inner closure as part of the bytessink
+  // protocol.
+  void *subc;
+
+  // The output buffer and limit, and our current write position.  "buf"
+  // initially points to "initbuf", but is dynamically allocated if we need to
+  // grow beyond the initial size.
+  char *buf, *ptr, *limit;
+
+  // The beginning of the current run, or undefined if we are at the top level.
+  char *runbegin;
+
+  // The list of segments we are accumulating.
+  upb_pb_encoder_segment *segbuf, *segptr, *seglimit;
+
+  // The stack of enclosing submessages.  Each entry in the stack points to the
+  // segment where this submessage's length is being accumulated.
+  int stack[UPB_PBENCODER_MAX_NESTING], *top, *stacklimit;
+
+  // Depth of startmsg/endmsg calls.
+  int depth;
+
+  // Initial buffers for the output buffer and segment buffer.  If we outgrow
+  // these we will dynamically allocate bigger ones.
+  char initbuf[256];
+  upb_pb_encoder_segment seginitbuf[32];
+)));
+
+UPB_BEGIN_EXTERN_C
+
+const upb_handlers *upb_pb_encoder_newhandlers(const upb_msgdef *m,
+                                               const void *owner);
+void upb_pb_encoder_reset(upb_pb_encoder *e);
+upb_sink *upb_pb_encoder_input(upb_pb_encoder *p);
+void upb_pb_encoder_init(upb_pb_encoder *e, const upb_handlers *h);
+void upb_pb_encoder_resetoutput(upb_pb_encoder *e, upb_bytessink *output);
+void upb_pb_encoder_uninit(upb_pb_encoder *e);
+
+UPB_END_EXTERN_C
+
+#ifdef __cplusplus
+
+namespace upb {
+namespace pb {
+inline Encoder::Encoder(const upb::Handlers* handlers) {
+  upb_pb_encoder_init(this, handlers);
+}
+inline Encoder::~Encoder() {
+  upb_pb_encoder_uninit(this);
+}
+inline void Encoder::Reset() {
+  upb_pb_encoder_reset(this);
+}
+inline void Encoder::ResetOutput(BytesSink* output) {
+  upb_pb_encoder_resetoutput(this, output);
+}
+inline Sink* Encoder::input() {
+  return upb_pb_encoder_input(this);
+}
+inline reffed_ptr<const Handlers> Encoder::NewHandlers(
+    const upb::MessageDef *md) {
+  const Handlers* h = upb_pb_encoder_newhandlers(md, &h);
+  return reffed_ptr<const Handlers>(h, &h);
+}
+}  // namespace pb
+}  // namespace upb
+
+#endif
+
+#endif  /* UPB_ENCODER_H_ */
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2011-2012 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * upb's core components like upb_decoder and upb_msg are carefully designed to
+ * avoid depending on each other for maximum orthogonality.  In other words,
+ * you can use a upb_decoder to decode into *any* kind of structure; upb_msg is
+ * just one such structure.  A upb_msg can be serialized/deserialized into any
+ * format, protobuf binary format is just one such format.
+ *
+ * However, for convenience we provide functions here for doing common
+ * operations like deserializing protobuf binary format into a upb_msg.  The
+ * compromise is that this file drags in almost all of upb as a dependency,
+ * which could be undesirable if you're trying to use a trimmed-down build of
+ * upb.
+ *
+ * While these routines are convenient, they do not reuse any encoding/decoding
+ * state.  For example, if a decoder is JIT-based, it will be re-JITted every
+ * time these functions are called.  For this reason, if you are parsing lots
+ * of data and efficiency is an issue, these may not be the best functions to
+ * use (though they are useful for prototyping, before optimizing).
+ */
+
+#ifndef UPB_GLUE_H
+#define UPB_GLUE_H
+
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Loads all defs from the given protobuf binary descriptor, setting default
+// accessors and a default layout on all messages.  The caller owns the
+// returned array of defs, which will be of length *n.  On error NULL is
+// returned and status is set (if non-NULL).
+upb_def **upb_load_defs_from_descriptor(const char *str, size_t len, int *n,
+                                        void *owner, upb_status *status);
+
+// Like the previous but also adds the loaded defs to the given symtab.
+bool upb_load_descriptor_into_symtab(upb_symtab *symtab, const char *str,
+                                     size_t len, upb_status *status);
+
+// Like the previous but also reads the descriptor from the given filename.
+bool upb_load_descriptor_file_into_symtab(upb_symtab *symtab, const char *fname,
+                                          upb_status *status);
+
+// Reads the given filename into a character string, returning NULL if there
+// was an error.
+char *upb_readfile(const char *filename, size_t *len);
+
+#ifdef __cplusplus
+}  /* extern "C" */
+
+namespace upb {
+
+// All routines that load descriptors expect the descriptor to be a
+// FileDescriptorSet.
+inline bool LoadDescriptorFileIntoSymtab(SymbolTable* s, const char *fname,
+                                         Status* status) {
+  return upb_load_descriptor_file_into_symtab(s, fname, status);
+}
+
+inline bool LoadDescriptorIntoSymtab(SymbolTable* s, const char* str,
+                                     size_t len, Status* status) {
+  return upb_load_descriptor_into_symtab(s, str, len, status);
+}
+
+// Templated so it can accept both string and std::string.
+template <typename T>
+bool LoadDescriptorIntoSymtab(SymbolTable* s, const T& desc, Status* status) {
+  return upb_load_descriptor_into_symtab(s, desc.c_str(), desc.size(), status);
+}
+
+}  // namespace upb
+
+#endif
+
+#endif
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ */
+
+#ifndef UPB_TEXT_H_
+#define UPB_TEXT_H_
+
+
+#ifdef __cplusplus
+namespace upb {
+namespace pb {
+class TextPrinter;
+}  // namespace pb
+}  // namespace upb
+#endif
+
+UPB_DECLARE_TYPE(upb::pb::TextPrinter, upb_textprinter);
+
+UPB_DEFINE_CLASS0(upb::pb::TextPrinter,
+ public:
+  // The given handlers must have come from NewHandlers().  It must outlive the
+  // TextPrinter.
+  explicit TextPrinter(const upb::Handlers* handlers);
+
+  void SetSingleLineMode(bool single_line);
+
+  bool ResetOutput(BytesSink* output);
+  Sink* input();
+
+  // If handler caching becomes a requirement we can add a code cache as in
+  // decoder.h
+  static reffed_ptr<const Handlers> NewHandlers(const MessageDef* md);
+
+ private:
+,
+UPB_DEFINE_STRUCT0(upb_textprinter,
+  upb_sink input_;
+  upb_bytessink *output_;
+  int indent_depth_;
+  bool single_line_;
+  void *subc;
+));
+
+UPB_BEGIN_EXTERN_C  // {
+
+// C API.
+void upb_textprinter_init(upb_textprinter *p, const upb_handlers *h);
+void upb_textprinter_uninit(upb_textprinter *p);
+bool upb_textprinter_resetoutput(upb_textprinter *p, upb_bytessink *output);
+void upb_textprinter_setsingleline(upb_textprinter *p, bool single_line);
+upb_sink *upb_textprinter_input(upb_textprinter *p);
+
+const upb_handlers *upb_textprinter_newhandlers(const upb_msgdef *m,
+                                                const void *owner);
+
+UPB_END_EXTERN_C  // }
+
+#ifdef __cplusplus
+
+namespace upb {
+namespace pb {
+inline TextPrinter::TextPrinter(const upb::Handlers* handlers) {
+  upb_textprinter_init(this, handlers);
+}
+inline void TextPrinter::SetSingleLineMode(bool single_line) {
+  upb_textprinter_setsingleline(this, single_line);
+}
+inline bool TextPrinter::ResetOutput(BytesSink* output) {
+  return upb_textprinter_resetoutput(this, output);
+}
+inline Sink* TextPrinter::input() {
+  return upb_textprinter_input(this);
+}
+inline reffed_ptr<const Handlers> TextPrinter::NewHandlers(
+    const MessageDef *md) {
+  const Handlers* h = upb_textprinter_newhandlers(md, &h);
+  return reffed_ptr<const Handlers>(h, &h);
+}
+}  // namespace pb
+}  // namespace upb
+
+#endif
+
+#endif  /* UPB_TEXT_H_ */
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2014 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * upb::json::Parser can parse JSON according to a specific schema.
+ * Support for parsing arbitrary JSON (schema-less) will be added later.
+ */
+
+#ifndef UPB_JSON_PARSER_H_
+#define UPB_JSON_PARSER_H_
+
+
+#ifdef __cplusplus
+namespace upb {
+namespace json {
+class Parser;
+}  // namespace json
+}  // namespace upb
+#endif
+
+UPB_DECLARE_TYPE(upb::json::Parser, upb_json_parser);
+
+// Internal-only struct used by the parser.
+typedef struct {
+ UPB_PRIVATE_FOR_CPP
+  upb_sink sink;
+  const upb_msgdef *m;
+  const upb_fielddef *f;
+} upb_jsonparser_frame;
+
+
+/* upb::json::Parser **********************************************************/
+
+#define UPB_JSON_MAX_DEPTH 64
+
+// Parses an incoming BytesStream, pushing the results to the destination sink.
+UPB_DEFINE_CLASS0(upb::json::Parser,
+ public:
+  Parser(Status* status);
+  ~Parser();
+
+  // Resets the state of the printer, so that it will expect to begin a new
+  // document.
+  void Reset();
+
+  // Resets the output pointer which will serve as our closure.  Implies
+  // Reset().
+  void ResetOutput(Sink* output);
+
+  // The input to the printer.
+  BytesSink* input();
+,
+UPB_DEFINE_STRUCT0(upb_json_parser,
+  upb_byteshandler input_handler_;
+  upb_bytessink input_;
+
+  // Stack to track the JSON scopes we are in.
+  upb_jsonparser_frame stack[UPB_JSON_MAX_DEPTH];
+  upb_jsonparser_frame *top;
+  upb_jsonparser_frame *limit;
+
+  upb_status *status;
+
+  // Ragel's internal parsing stack for the parsing state machine.
+  int current_state;
+  int parser_stack[UPB_JSON_MAX_DEPTH];
+  int parser_top;
+
+  // A pointer to the beginning of whatever text we are currently parsing.
+  const char *text_begin;
+
+  // We have to accumulate text for member names, integers, unicode escapes, and
+  // base64 partial results.
+  const char *accumulated;
+  size_t accumulated_len;
+  // TODO: add members and code for allocating a buffer when necessary (when the
+  // member spans input buffers or contains escapes).
+));
+
+UPB_BEGIN_EXTERN_C
+
+void upb_json_parser_init(upb_json_parser *p, upb_status *status);
+void upb_json_parser_uninit(upb_json_parser *p);
+void upb_json_parser_reset(upb_json_parser *p);
+void upb_json_parser_resetoutput(upb_json_parser *p, upb_sink *output);
+upb_bytessink *upb_json_parser_input(upb_json_parser *p);
+
+UPB_END_EXTERN_C
+
+#ifdef __cplusplus
+
+namespace upb {
+namespace json {
+inline Parser::Parser(Status* status) { upb_json_parser_init(this, status); }
+inline Parser::~Parser() { upb_json_parser_uninit(this); }
+inline void Parser::Reset() { upb_json_parser_reset(this); }
+inline void Parser::ResetOutput(Sink* output) {
+  upb_json_parser_resetoutput(this, output);
+}
+inline BytesSink* Parser::input() {
+  return upb_json_parser_input(this);
+}
+}  // namespace json
+}  // namespace upb
+
+#endif
+
+
+#endif  // UPB_JSON_PARSER_H_
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2014 Google Inc.  See LICENSE for details.
+ * Author: Josh Haberman <jhaberman@gmail.com>
+ *
+ * upb::json::Printer allows you to create handlers that emit JSON
+ * according to a specific protobuf schema.
+ */
+
+#ifndef UPB_JSON_TYPED_PRINTER_H_
+#define UPB_JSON_TYPED_PRINTER_H_
+
+
+#ifdef __cplusplus
+namespace upb {
+namespace json {
+class Printer;
+}  // namespace json
+}  // namespace upb
+#endif
+
+UPB_DECLARE_TYPE(upb::json::Printer, upb_json_printer);
+
+
+/* upb::json::Printer *********************************************************/
+
+// Prints an incoming stream of data to a BytesSink in JSON format.
+UPB_DEFINE_CLASS0(upb::json::Printer,
+ public:
+  Printer(const upb::Handlers* handlers);
+  ~Printer();
+
+  // Resets the state of the printer, so that it will expect to begin a new
+  // document.
+  void Reset();
+
+  // Resets the output pointer which will serve as our closure.  Implies
+  // Reset().
+  void ResetOutput(BytesSink* output);
+
+  // The input to the printer.
+  Sink* input();
+
+  // Returns handlers for printing according to the specified schema.
+  static reffed_ptr<const Handlers> NewHandlers(const upb::MessageDef* md);
+,
+UPB_DEFINE_STRUCT0(upb_json_printer,
+  upb_sink input_;
+  // BytesSink closure.
+  void *subc_;
+  upb_bytessink *output_;
+
+  // We track the depth so that we know when to emit startstr/endstr on the
+  // output.
+  int depth_;
+  // Have we emitted the first element? This state is necessary to emit commas
+  // without leaving a trailing comma in arrays/maps. We keep this state per
+  // frame depth.
+  //
+  // Why max_depth * 2? UPB_MAX_HANDLER_DEPTH counts depth as nested messages.
+  // We count frames (contexts in which we separate elements by commas) as both
+  // repeated fields and messages (maps), and the worst case is a
+  // message->repeated field->submessage->repeated field->... nesting.
+  bool first_elem_[UPB_MAX_HANDLER_DEPTH * 2];
+));
+
+UPB_BEGIN_EXTERN_C  // {
+
+// Native C API.
+
+void upb_json_printer_init(upb_json_printer *p, const upb_handlers *h);
+void upb_json_printer_uninit(upb_json_printer *p);
+void upb_json_printer_reset(upb_json_printer *p);
+void upb_json_printer_resetoutput(upb_json_printer *p, upb_bytessink *output);
+upb_sink *upb_json_printer_input(upb_json_printer *p);
+const upb_handlers *upb_json_printer_newhandlers(const upb_msgdef *md,
+                                                 const void *owner);
+
+UPB_END_EXTERN_C  // }
+
+#ifdef __cplusplus
+
+namespace upb {
+namespace json {
+inline Printer::Printer(const upb::Handlers* handlers) {
+  upb_json_printer_init(this, handlers);
+}
+inline Printer::~Printer() { upb_json_printer_uninit(this); }
+inline void Printer::Reset() { upb_json_printer_reset(this); }
+inline void Printer::ResetOutput(BytesSink* output) {
+  upb_json_printer_resetoutput(this, output);
+}
+inline Sink* Printer::input() { return upb_json_printer_input(this); }
+inline reffed_ptr<const Handlers> Printer::NewHandlers(
+    const upb::MessageDef *md) {
+  const Handlers* h = upb_json_printer_newhandlers(md, &h);
+  return reffed_ptr<const Handlers>(h, &h);
+}
+}  // namespace json
+}  // namespace upb
+
+#endif
+
+#endif  // UPB_JSON_TYPED_PRINTER_H_