13 files changed, 48 insertions, 21 deletions
diff --git a/absl/flags/internal/commandlineflag.h b/absl/flags/internal/commandlineflag.h
index 3c149788..cb46fe2e 100644
--- a/absl/flags/internal/commandlineflag.h
+++ b/absl/flags/internal/commandlineflag.h
@@ -16,13 +16,8 @@
 #ifndef ABSL_FLAGS_INTERNAL_COMMANDLINEFLAG_H_
 #define ABSL_FLAGS_INTERNAL_COMMANDLINEFLAG_H_
 
-#include <memory>
-#include <string>
-
 #include "absl/base/config.h"
 #include "absl/base/internal/fast_type_id.h"
-#include "absl/base/macros.h"
-#include "absl/strings/string_view.h"
 
 namespace absl {
 ABSL_NAMESPACE_BEGIN
@@ -33,7 +28,7 @@ namespace flags_internal {
 // cases this id is enough to uniquely identify the flag's value type. In a few
 // cases we'll have to resort to using actual RTTI implementation if it is
 // available.
-using FlagFastTypeId = base_internal::FastTypeIdType;
+using FlagFastTypeId = absl::base_internal::FastTypeIdType;
 
 // Options that control SetCommandLineOptionWithMode.
 enum FlagSettingMode {
diff --git a/absl/flags/internal/flag.cc b/absl/flags/internal/flag.cc
index ee974244..1502e7f1 100644
--- a/absl/flags/internal/flag.cc
+++ b/absl/flags/internal/flag.cc
@@ -15,21 +15,26 @@
 
 #include "absl/flags/internal/flag.h"
 
+#include <assert.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
 
+#include <array>
 #include <atomic>
 #include <memory>
+#include <new>
 #include <string>
-#include <vector>
+#include <typeinfo>
 
-#include "absl/base/attributes.h"
+#include "absl/base/call_once.h"
 #include "absl/base/casts.h"
 #include "absl/base/config.h"
-#include "absl/base/const_init.h"
 #include "absl/base/optimization.h"
+#include "absl/flags/config.h"
+#include "absl/flags/internal/commandlineflag.h"
 #include "absl/flags/usage_config.h"
+#include "absl/memory/memory.h"
 #include "absl/strings/str_cat.h"
 #include "absl/strings/string_view.h"
 #include "absl/synchronization/mutex.h"
diff --git a/absl/flags/internal/flag.h b/absl/flags/internal/flag.h
index e1885809..2cc44e00 100644
--- a/absl/flags/internal/flag.h
+++ b/absl/flags/internal/flag.h
@@ -16,31 +16,36 @@
 #ifndef ABSL_FLAGS_INTERNAL_FLAG_H_
 #define ABSL_FLAGS_INTERNAL_FLAG_H_
 
+#include <stddef.h>
 #include <stdint.h>
 
 #include <atomic>
 #include <cstring>
 #include <memory>
+#include <new>
 #include <string>
 #include <type_traits>
 #include <typeinfo>
 
+#include "absl/base/attributes.h"
 #include "absl/base/call_once.h"
 #include "absl/base/config.h"
+#include "absl/base/optimization.h"
 #include "absl/base/thread_annotations.h"
 #include "absl/flags/commandlineflag.h"
 #include "absl/flags/config.h"
+#include "absl/flags/internal/commandlineflag.h"
 #include "absl/flags/internal/registry.h"
 #include "absl/flags/marshalling.h"
-#include "absl/memory/memory.h"
 #include "absl/meta/type_traits.h"
-#include "absl/strings/str_cat.h"
 #include "absl/strings/string_view.h"
 #include "absl/synchronization/mutex.h"
+#include "absl/utility/utility.h"
 
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 
+///////////////////////////////////////////////////////////////////////////////
 // Forward declaration of absl::Flag<T> public API.
 namespace flags_internal {
 template <typename T>
@@ -64,12 +69,15 @@ void SetFlag(absl::Flag<T>* flag, const T& v);
 template <typename T, typename V>
 void SetFlag(absl::Flag<T>* flag, const V& v);
 
-namespace flags_internal {
+template <typename U>
+const CommandLineFlag& GetFlagReflectionHandle(const absl::Flag<U>& f);
 
 ///////////////////////////////////////////////////////////////////////////////
 // Flag value type operations, eg., parsing, copying, etc. are provided
 // by function specific to that type with a signature matching FlagOpFn.
 
+namespace flags_internal {
+
 enum class FlagOp {
   kAlloc,
   kDelete,
@@ -659,6 +667,13 @@ class Flag {
     impl_.Write(&v);
   }
 
+  template <typename U>
+  friend const CommandLineFlag& absl::GetFlagReflectionHandle(
+      const absl::Flag<U>& f);
+
+  // Access to the reflection.
+  const CommandLineFlag& Reflect() const { return impl_; }
+
   // Flag's data
   // The implementation depends on value_ field to be placed exactly after the
   // impl_ field, so that impl_ can figure out the offset to the value and
diff --git a/absl/flags/internal/parse.h b/absl/flags/internal/parse.h
index d259be73..de706c89 100644
--- a/absl/flags/internal/parse.h
+++ b/absl/flags/internal/parse.h
@@ -21,6 +21,7 @@
 
 #include "absl/base/config.h"
 #include "absl/flags/declare.h"
+#include "absl/strings/string_view.h"
 
 ABSL_DECLARE_FLAG(std::vector<std::string>, flagfile);
 ABSL_DECLARE_FLAG(std::vector<std::string>, fromenv);
diff --git a/absl/flags/internal/path_util.h b/absl/flags/internal/path_util.h
index 365c8305..a6594d33 100644
--- a/absl/flags/internal/path_util.h
+++ b/absl/flags/internal/path_util.h
@@ -17,7 +17,6 @@
 #define ABSL_FLAGS_INTERNAL_PATH_UTIL_H_
 
 #include "absl/base/config.h"
-#include "absl/strings/match.h"
 #include "absl/strings/string_view.h"
 
 namespace absl {
diff --git a/absl/flags/internal/private_handle_accessor.cc b/absl/flags/internal/private_handle_accessor.cc
index 24b49136..a7eb58b6 100644
--- a/absl/flags/internal/private_handle_accessor.cc
+++ b/absl/flags/internal/private_handle_accessor.cc
@@ -15,6 +15,14 @@
 
 #include "absl/flags/internal/private_handle_accessor.h"
 
+#include <memory>
+#include <string>
+
+#include "absl/base/config.h"
+#include "absl/flags/commandlineflag.h"
+#include "absl/flags/internal/commandlineflag.h"
+#include "absl/strings/string_view.h"
+
 namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace flags_internal {
diff --git a/absl/flags/internal/private_handle_accessor.h b/absl/flags/internal/private_handle_accessor.h
index 9a327a07..c64435cd 100644
--- a/absl/flags/internal/private_handle_accessor.h
+++ b/absl/flags/internal/private_handle_accessor.h
@@ -16,7 +16,13 @@
 #ifndef ABSL_FLAGS_INTERNAL_PRIVATE_HANDLE_ACCESSOR_H_
 #define ABSL_FLAGS_INTERNAL_PRIVATE_HANDLE_ACCESSOR_H_
 
+#include <memory>
+#include <string>
+
+#include "absl/base/config.h"
 #include "absl/flags/commandlineflag.h"
+#include "absl/flags/internal/commandlineflag.h"
+#include "absl/strings/string_view.h"
 
 namespace absl {
 ABSL_NAMESPACE_BEGIN
diff --git a/absl/flags/internal/registry.cc b/absl/flags/internal/registry.cc
index 4bcebfa9..e582d79d 100644
--- a/absl/flags/internal/registry.cc
+++ b/absl/flags/internal/registry.cc
@@ -29,6 +29,7 @@
 #include "absl/base/internal/raw_logging.h"
 #include "absl/base/thread_annotations.h"
 #include "absl/flags/commandlineflag.h"
+#include "absl/flags/internal/commandlineflag.h"
 #include "absl/flags/internal/private_handle_accessor.h"
 #include "absl/flags/usage_config.h"
 #include "absl/strings/str_cat.h"
diff --git a/absl/flags/internal/registry.h b/absl/flags/internal/registry.h
index a118865a..d207c225 100644
--- a/absl/flags/internal/registry.h
+++ b/absl/flags/internal/registry.h
@@ -17,11 +17,9 @@
 #define ABSL_FLAGS_INTERNAL_REGISTRY_H_
 
 #include <functional>
-#include <map>
-#include <string>
 
 #include "absl/base/config.h"
-#include "absl/base/macros.h"
+#include "absl/flags/commandlineflag.h"
 #include "absl/flags/internal/commandlineflag.h"
 #include "absl/strings/string_view.h"
 
@@ -30,8 +28,6 @@
 
 namespace absl {
 ABSL_NAMESPACE_BEGIN
-class CommandLineFlag;
-
 namespace flags_internal {
 
 CommandLineFlag* FindCommandLineFlag(absl::string_view name);
diff --git a/absl/flags/internal/type_erased.h b/absl/flags/internal/type_erased.h
index fd9663e2..437a8c28 100644
--- a/absl/flags/internal/type_erased.h
+++ b/absl/flags/internal/type_erased.h
@@ -20,6 +20,7 @@
 
 #include "absl/base/config.h"
 #include "absl/flags/commandlineflag.h"
+#include "absl/flags/internal/commandlineflag.h"
 #include "absl/flags/internal/registry.h"
 #include "absl/strings/string_view.h"
 
diff --git a/absl/flags/internal/type_erased_test.cc b/absl/flags/internal/type_erased_test.cc
index bb0ff23e..42f374dc 100644
--- a/absl/flags/internal/type_erased_test.cc
+++ b/absl/flags/internal/type_erased_test.cc
@@ -20,8 +20,8 @@
 
 #include "gtest/gtest.h"
 #include "absl/flags/flag.h"
+#include "absl/flags/internal/commandlineflag.h"
 #include "absl/flags/internal/registry.h"
-#include "absl/flags/marshalling.h"
 #include "absl/memory/memory.h"
 
 ABSL_FLAG(int, int_flag, 1, "int_flag help");
diff --git a/absl/flags/internal/usage.cc b/absl/flags/internal/usage.cc
index 2a2231a7..35b6427b 100644
--- a/absl/flags/internal/usage.cc
+++ b/absl/flags/internal/usage.cc
@@ -15,6 +15,8 @@
 
 #include "absl/flags/internal/usage.h"
 
+#include <stdint.h>
+
 #include <functional>
 #include <map>
 #include <ostream>
diff --git a/absl/flags/internal/usage_test.cc b/absl/flags/internal/usage_test.cc
index 8dd3532e..53b4d983 100644
--- a/absl/flags/internal/usage_test.cc
+++ b/absl/flags/internal/usage_test.cc
@@ -21,7 +21,6 @@
 #include <string>
 
 #include "gtest/gtest.h"
-#include "absl/flags/declare.h"
 #include "absl/flags/flag.h"
 #include "absl/flags/internal/parse.h"
 #include "absl/flags/internal/path_util.h"
@@ -29,7 +28,6 @@
 #include "absl/flags/internal/registry.h"
 #include "absl/flags/usage.h"
 #include "absl/flags/usage_config.h"
-#include "absl/memory/memory.h"
 #include "absl/strings/match.h"
 #include "absl/strings/string_view.h"