Add nullability annotations

PiperOrigin-RevId: 589842893
Change-Id: I9657761d1f71c665582406f278c6605f6d382f6d

5 files changed, 45 insertions, 27 deletions

diff --git a/absl/base/BUILD.bazel b/absl/base/BUILD.bazel
index 60d05a83..06bd4950 100644
--- a/absl/base/BUILD.bazel
+++ b/absl/base/BUILD.bazel
@@ -287,6 +287,7 @@ cc_library(
         ":cycleclock_internal",
         ":dynamic_annotations",
         ":log_severity",
+        ":nullability",
         ":raw_logging_internal",
         ":spinlock_wait",
         "//absl/meta:type_traits",
@@ -549,6 +550,7 @@ cc_library(
         ":base",
         ":config",
         ":core_headers",
+        ":nullability",
     ],
 )
 
diff --git a/absl/base/CMakeLists.txt b/absl/base/CMakeLists.txt
index 9ca5cf8b..4cfc2285 100644
--- a/absl/base/CMakeLists.txt
+++ b/absl/base/CMakeLists.txt
@@ -247,6 +247,7 @@ absl_cc_library(
     absl::core_headers
     absl::dynamic_annotations
     absl::log_severity
+    absl::nullability
     absl::raw_logging_internal
     absl::spinlock_wait
     absl::type_traits
@@ -475,6 +476,7 @@ absl_cc_library(
     absl::base
     absl::config
     absl::core_headers
+    absl::nullability
   PUBLIC
 )
 
diff --git a/absl/base/call_once.h b/absl/base/call_once.h
index 08436bac..7b0e69cc 100644
--- a/absl/base/call_once.h
+++ b/absl/base/call_once.h
@@ -37,6 +37,7 @@
 #include "absl/base/internal/scheduling_mode.h"
 #include "absl/base/internal/spinlock_wait.h"
 #include "absl/base/macros.h"
+#include "absl/base/nullability.h"
 #include "absl/base/optimization.h"
 #include "absl/base/port.h"
 
@@ -46,7 +47,8 @@ ABSL_NAMESPACE_BEGIN
 class once_flag;
 
 namespace base_internal {
-std::atomic<uint32_t>* ControlWord(absl::once_flag* flag);
+absl::Nonnull<std::atomic<uint32_t>*> ControlWord(
+    absl::Nonnull<absl::once_flag*> flag);
 }  // namespace base_internal
 
 // call_once()
@@ -89,7 +91,8 @@ class once_flag {
   once_flag& operator=(const once_flag&) = delete;
 
  private:
-  friend std::atomic<uint32_t>* base_internal::ControlWord(once_flag* flag);
+  friend absl::Nonnull<std::atomic<uint32_t>*> base_internal::ControlWord(
+      absl::Nonnull<once_flag*> flag);
   std::atomic<uint32_t> control_;
 };
 
@@ -103,7 +106,8 @@ namespace base_internal {
 // Like call_once, but uses KERNEL_ONLY scheduling. Intended to be used to
 // initialize entities used by the scheduler implementation.
 template <typename Callable, typename... Args>
-void LowLevelCallOnce(absl::once_flag* flag, Callable&& fn, Args&&... args);
+void LowLevelCallOnce(absl::Nonnull<absl::once_flag*> flag, Callable&& fn,
+                      Args&&... args);
 
 // Disables scheduling while on stack when scheduling mode is non-cooperative.
 // No effect for cooperative scheduling modes.
@@ -143,10 +147,10 @@ enum {
 };
 
 template <typename Callable, typename... Args>
-ABSL_ATTRIBUTE_NOINLINE
-void CallOnceImpl(std::atomic<uint32_t>* control,
-                  base_internal::SchedulingMode scheduling_mode, Callable&& fn,
-                  Args&&... args) {
+ABSL_ATTRIBUTE_NOINLINE void CallOnceImpl(
+    absl::Nonnull<std::atomic<uint32_t>*> control,
+    base_internal::SchedulingMode scheduling_mode, Callable&& fn,
+    Args&&... args) {
 #ifndef NDEBUG
   {
     uint32_t old_control = control->load(std::memory_order_relaxed);
@@ -185,12 +189,14 @@ void CallOnceImpl(std::atomic<uint32_t>* control,
   }  // else *control is already kOnceDone
 }
 
-inline std::atomic<uint32_t>* ControlWord(once_flag* flag) {
+inline absl::Nonnull<std::atomic<uint32_t>*> ControlWord(
+    absl::Nonnull<once_flag*> flag) {
   return &flag->control_;
 }
 
 template <typename Callable, typename... Args>
-void LowLevelCallOnce(absl::once_flag* flag, Callable&& fn, Args&&... args) {
+void LowLevelCallOnce(absl::Nonnull<absl::once_flag*> flag, Callable&& fn,
+                      Args&&... args) {
   std::atomic<uint32_t>* once = base_internal::ControlWord(flag);
   uint32_t s = once->load(std::memory_order_acquire);
   if (ABSL_PREDICT_FALSE(s != base_internal::kOnceDone)) {
diff --git a/absl/base/internal/endian.h b/absl/base/internal/endian.h
index 50747d75..943f3d97 100644
--- a/absl/base/internal/endian.h
+++ b/absl/base/internal/endian.h
@@ -22,6 +22,7 @@
 #include "absl/base/casts.h"
 #include "absl/base/config.h"
 #include "absl/base/internal/unaligned_access.h"
+#include "absl/base/nullability.h"
 #include "absl/base/port.h"
 
 namespace absl {
@@ -160,27 +161,27 @@ inline int64_t ToHost(int64_t x) {
 }
 
 // Functions to do unaligned loads and stores in little-endian order.
-inline uint16_t Load16(const void *p) {
+inline uint16_t Load16(absl::Nonnull<const void *> p) {
   return ToHost16(ABSL_INTERNAL_UNALIGNED_LOAD16(p));
 }
 
-inline void Store16(void *p, uint16_t v) {
+inline void Store16(absl::Nonnull<void *> p, uint16_t v) {
   ABSL_INTERNAL_UNALIGNED_STORE16(p, FromHost16(v));
 }
 
-inline uint32_t Load32(const void *p) {
+inline uint32_t Load32(absl::Nonnull<const void *> p) {
   return ToHost32(ABSL_INTERNAL_UNALIGNED_LOAD32(p));
 }
 
-inline void Store32(void *p, uint32_t v) {
+inline void Store32(absl::Nonnull<void *> p, uint32_t v) {
   ABSL_INTERNAL_UNALIGNED_STORE32(p, FromHost32(v));
 }
 
-inline uint64_t Load64(const void *p) {
+inline uint64_t Load64(absl::Nonnull<const void *> p) {
   return ToHost64(ABSL_INTERNAL_UNALIGNED_LOAD64(p));
 }
 
-inline void Store64(void *p, uint64_t v) {
+inline void Store64(absl::Nonnull<void *> p, uint64_t v) {
   ABSL_INTERNAL_UNALIGNED_STORE64(p, FromHost64(v));
 }
 
@@ -250,27 +251,27 @@ inline int64_t ToHost(int64_t x) {
 }
 
 // Functions to do unaligned loads and stores in big-endian order.
-inline uint16_t Load16(const void *p) {
+inline uint16_t Load16(absl::Nonnull<const void *> p) {
   return ToHost16(ABSL_INTERNAL_UNALIGNED_LOAD16(p));
 }
 
-inline void Store16(void *p, uint16_t v) {
+inline void Store16(absl::Nonnull<void *> p, uint16_t v) {
   ABSL_INTERNAL_UNALIGNED_STORE16(p, FromHost16(v));
 }
 
-inline uint32_t Load32(const void *p) {
+inline uint32_t Load32(absl::Nonnull<const void *> p) {
   return ToHost32(ABSL_INTERNAL_UNALIGNED_LOAD32(p));
 }
 
-inline void Store32(void *p, uint32_t v) {
+inline void Store32(absl::Nonnull<void *>p, uint32_t v) {
   ABSL_INTERNAL_UNALIGNED_STORE32(p, FromHost32(v));
 }
 
-inline uint64_t Load64(const void *p) {
+inline uint64_t Load64(absl::Nonnull<const void *> p) {
   return ToHost64(ABSL_INTERNAL_UNALIGNED_LOAD64(p));
 }
 
-inline void Store64(void *p, uint64_t v) {
+inline void Store64(absl::Nonnull<void *> p, uint64_t v) {
   ABSL_INTERNAL_UNALIGNED_STORE64(p, FromHost64(v));
 }
 
diff --git a/absl/base/internal/unaligned_access.h b/absl/base/internal/unaligned_access.h
index 093dd9b4..4fea4574 100644
--- a/absl/base/internal/unaligned_access.h
+++ b/absl/base/internal/unaligned_access.h
@@ -23,6 +23,7 @@
 
 #include "absl/base/attributes.h"
 #include "absl/base/config.h"
+#include "absl/base/nullability.h"
 
 // unaligned APIs
 
@@ -35,29 +36,35 @@ namespace absl {
 ABSL_NAMESPACE_BEGIN
 namespace base_internal {
 
-inline uint16_t UnalignedLoad16(const void *p) {
+inline uint16_t UnalignedLoad16(absl::Nonnull<const void *> p) {
   uint16_t t;
   memcpy(&t, p, sizeof t);
   return t;
 }
 
-inline uint32_t UnalignedLoad32(const void *p) {
+inline uint32_t UnalignedLoad32(absl::Nonnull<const void *> p) {
   uint32_t t;
   memcpy(&t, p, sizeof t);
   return t;
 }
 
-inline uint64_t UnalignedLoad64(const void *p) {
+inline uint64_t UnalignedLoad64(absl::Nonnull<const void *> p) {
   uint64_t t;
   memcpy(&t, p, sizeof t);
   return t;
 }
 
-inline void UnalignedStore16(void *p, uint16_t v) { memcpy(p, &v, sizeof v); }
+inline void UnalignedStore16(absl::Nonnull<void *> p, uint16_t v) {
+  memcpy(p, &v, sizeof v);
+}
 
-inline void UnalignedStore32(void *p, uint32_t v) { memcpy(p, &v, sizeof v); }
+inline void UnalignedStore32(absl::Nonnull<void *> p, uint32_t v) {
+  memcpy(p, &v, sizeof v);
+}
 
-inline void UnalignedStore64(void *p, uint64_t v) { memcpy(p, &v, sizeof v); }
+inline void UnalignedStore64(absl::Nonnull<void *> p, uint64_t v) {
+  memcpy(p, &v, sizeof v);
+}
 
 }  // namespace base_internal
 ABSL_NAMESPACE_END