Roll abseil_revision 049aa40e7e..166d71d18f

Change Log:
049aa40e7e..166d71d18f
Full diff:
049aa40e7e..166d71d18f

No .def changes

Bug: None
Change-Id: Ic5c8c93ce285933bd4c2a0fac40e2e331ecc3565
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4629756
Auto-Submit: Danil Chapovalov <danilchap@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1160761}

DEPS

@@ -4426,6 +4426,7 @@ include_rules = [
   # //styleguide/c++/c++-features.md.
   '+third_party/abseil-cpp',
   '-third_party/abseil-cpp/absl/algorithm/container.h',
+  '-third_party/abseil-cpp/absl/base/nullability.h',
   '-third_party/abseil-cpp/absl/container',
   '-third_party/abseil-cpp/absl/crc',
   '-third_party/abseil-cpp/absl/flags',

styleguide/c++/c++-features.md

@@ -39,6 +39,7 @@ The current status of existing standards and Abseil features is:
       * absl::AnyInvocable: Initially supported June 20, 2022
       * Log library: Initially supported Aug 31, 2022
       * CRC32C library: Initially supported Dec 5, 2022
+      * Nullability annotation: Initially supported Jun 21, 2023
 
 [TOC]
 
@@ -1872,3 +1873,23 @@ absl::AddLogSink(&custom_sink_to_capture_absl_logs);
 *** promo
 Overlaps and uses same macros names as `base/logging.h`.
 ***
+
+### Nullability annotations <sup>[tbd]</sup>
+
+```c++
+void PaySalary(absl::NotNull<Employee *> employee) {
+  pay(*employee);  // OK to dereference
+}
+```
+
+**Description:** Annotations to more clearly specify contracts
+
+**Documentation:**
+[nullability.h](https://source.chromium.org/chromium/chromium/src/+/main:third_party/abseil-cpp/absl/base/nullability.h)
+
+**Notes:**
+*** promo
+These nullability annotations are primarily a human readable signal about the
+intended contract of the pointer. They are not *types* and do not currently
+provide any correctness guarantees.
+***

third_party/abseil-cpp/BUILD.gn

@@ -61,6 +61,7 @@ group("absl_component_deps") {
     "//third_party/abseil-cpp/absl/base",
     "//third_party/abseil-cpp/absl/base:config",
     "//third_party/abseil-cpp/absl/base:core_headers",
+    "//third_party/abseil-cpp/absl/base:nullability",
     "//third_party/abseil-cpp/absl/base:prefetch",
     "//third_party/abseil-cpp/absl/cleanup",
     "//third_party/abseil-cpp/absl/container:btree",
@@ -189,6 +190,7 @@ if (build_with_chromium) {
         "absl/algorithm:algorithm_test",
         "absl/algorithm:container_test",
         "absl/base:config_test",
+        "absl/base:nullability_test",
         "absl/base:prefetch_test",
         "absl/cleanup:cleanup_test",
         # TODO(mbonadei): Fix issue with EXPECT_DEATH and uncomment.

third_party/abseil-cpp/CMake/AbseilDll.cmake

@@ -25,6 +25,7 @@ set(ABSL_INTERNAL_DLL_FILES
   "base/internal/low_level_alloc.cc"
   "base/internal/low_level_alloc.h"
   "base/internal/low_level_scheduling.h"
+  "base/internal/nullability_impl.h"
   "base/internal/per_thread_tls.h"
   "base/internal/prefetch.h"
   "base/prefetch.h"
@@ -54,6 +55,7 @@ set(ABSL_INTERNAL_DLL_FILES
   "base/log_severity.cc"
   "base/log_severity.h"
   "base/macros.h"
+  "base/nullability.h"
   "base/optimization.h"
   "base/options.h"
   "base/policy_checks.h"

third_party/abseil-cpp/README.chromium

@@ -4,7 +4,7 @@ URL: https://github.com/abseil/abseil-cpp
 License: Apache 2.0
 License File: LICENSE
 Version: 0
-Revision: 049aa40e7ec9e37ed47c4dd2452affb13cd62ebe
+Revision: 166d71d18f01aa73fd35aae611692320952a75b5
 Security Critical: yes
 
 Description:

third_party/abseil-cpp/absl/base/BUILD.bazel

@@ -62,6 +62,18 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "nullability",
+    srcs = ["internal/nullability_impl.h"],
+    hdrs = ["nullability.h"],
+    copts = ABSL_DEFAULT_COPTS,
+    linkopts = ABSL_DEFAULT_LINKOPTS,
+    deps = [
+        ":core_headers",
+        "//absl/meta:type_traits",
+    ],
+)
+
 cc_library(
     name = "raw_logging_internal",
     srcs = ["internal/raw_logging.cc"],
@@ -546,6 +558,16 @@ cc_test(
     ],
 )
 
+cc_test(
+    name = "nullability_test",
+    srcs = ["nullability_test.cc"],
+    deps = [
+        ":core_headers",
+        ":nullability",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
 cc_test(
     name = "raw_logging_test",
     srcs = ["raw_logging_test.cc"],

third_party/abseil-cpp/absl/base/BUILD.gn

@@ -28,6 +28,15 @@ absl_source_set("log_severity") {
   ]
 }
 
+absl_source_set("nullability") {
+  sources = [ "internal/nullability_impl.h" ]
+  public = [ "nullability.h" ]
+  deps = [
+    ":core_headers",
+    "//third_party/abseil-cpp/absl/meta:type_traits",
+  ]
+}
+
 absl_source_set("raw_logging_internal") {
   sources = [ "internal/raw_logging.cc" ]
   public = [ "internal/raw_logging.h" ]
@@ -294,3 +303,11 @@ absl_test("config_test") {
     "//third_party/abseil-cpp/absl/synchronization:thread_pool",
   ]
 }
+
+absl_test("nullability_test") {
+  sources = [ "nullability_test.cc" ]
+  deps = [
+    ":core_headers",
+    ":nullability",
+  ]
+}

third_party/abseil-cpp/absl/base/CMakeLists.txt

@@ -54,6 +54,33 @@ absl_cc_library(
     ${ABSL_DEFAULT_COPTS}
 )
 
+absl_cc_library(
+  NAME
+    nullability
+  HDRS
+    "nullability.h"
+  SRCS
+    "internal/nullability_impl.h"
+  DEPS
+    absl::core_headers
+    absl::type_traits
+  COPTS
+    ${ABSL_DEFAULT_COPTS}
+)
+
+absl_cc_test(
+  NAME
+    nullability_test
+  SRCS
+    "nullability_test.cc"
+  COPTS
+    ${ABSL_TEST_COPTS}
+  DEPS
+    absl::core_headers
+    absl::nullability
+    GTest::gtest_main
+)
+
 # Internal-only target, do not depend on directly.
 absl_cc_library(
   NAME

third_party/abseil-cpp/absl/base/internal/nullability_impl.h

@@ -0,0 +1,106 @@
+// Copyright 2023 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ABSL_BASE_INTERNAL_NULLABILITY_IMPL_H_
+#define ABSL_BASE_INTERNAL_NULLABILITY_IMPL_H_
+
+#include <memory>
+#include <type_traits>
+
+#include "absl/base/attributes.h"
+#include "absl/meta/type_traits.h"
+
+namespace absl {
+
+namespace nullability_internal {
+
+// `IsNullabilityCompatible` checks whether its first argument is a class
+// explicitly tagged as supporting nullability annotations. The tag is the type
+// declaration `absl_nullability_compatible`.
+template <typename, typename = void>
+struct IsNullabilityCompatible : std::false_type {};
+
+template <typename T>
+struct IsNullabilityCompatible<
+    T, absl::void_t<typename T::absl_nullability_compatible>> : std::true_type {
+};
+
+template <typename T>
+constexpr bool IsSupportedType = IsNullabilityCompatible<T>::value;
+
+template <typename T>
+constexpr bool IsSupportedType<T*> = true;
+
+template <typename T, typename U>
+constexpr bool IsSupportedType<T U::*> = true;
+
+template <typename T, typename... Deleter>
+constexpr bool IsSupportedType<std::unique_ptr<T, Deleter...>> = true;
+
+template <typename T>
+constexpr bool IsSupportedType<std::shared_ptr<T>> = true;
+
+template <typename T>
+struct EnableNullable {
+  static_assert(nullability_internal::IsSupportedType<std::remove_cv_t<T>>,
+                "Template argument must be a raw or supported smart pointer "
+                "type. See absl/base/nullability.h.");
+  using type = T;
+};
+
+template <typename T>
+struct EnableNonNull {
+  static_assert(nullability_internal::IsSupportedType<std::remove_cv_t<T>>,
+                "Template argument must be a raw or supported smart pointer "
+                "type. See absl/base/nullability.h.");
+  using type = T;
+};
+
+template <typename T>
+struct EnableNullabilityUnknown {
+  static_assert(nullability_internal::IsSupportedType<std::remove_cv_t<T>>,
+                "Template argument must be a raw or supported smart pointer "
+                "type. See absl/base/nullability.h.");
+  using type = T;
+};
+
+// Note: we do not apply Clang nullability attributes (e.g. _Nullable).  These
+// only support raw pointers, and conditionally enabling them only for raw
+// pointers inhibits template arg deduction.  Ideally, they would support all
+// pointer-like types.
+template <typename T, typename = typename EnableNullable<T>::type>
+using NullableImpl
+#if ABSL_HAVE_CPP_ATTRIBUTE(clang::annotate)
+    [[clang::annotate("Nullable")]]
+#endif
+    = T;
+
+template <typename T, typename = typename EnableNonNull<T>::type>
+using NonNullImpl
+#if ABSL_HAVE_CPP_ATTRIBUTE(clang::annotate)
+    [[clang::annotate("Nonnull")]]
+#endif
+    = T;
+
+template <typename T, typename = typename EnableNullabilityUnknown<T>::type>
+using NullabilityUnknownImpl
+#if ABSL_HAVE_CPP_ATTRIBUTE(clang::annotate)
+    [[clang::annotate("Nullability_Unspecified")]]
+#endif
+    = T;
+
+}  // namespace nullability_internal
+}  // namespace absl
+
+#endif  // ABSL_BASE_INTERNAL_NULLABILITY_IMPL_H_

third_party/abseil-cpp/absl/base/internal/thread_identity.cc

@@ -58,18 +58,19 @@ void AllocateThreadIdentityKey(ThreadIdentityReclaimerFunction reclaimer) {
 // that protected visibility is unsupported.
 ABSL_CONST_INIT  // Must come before __attribute__((visibility("protected")))
 #if ABSL_HAVE_ATTRIBUTE(visibility) && !defined(__APPLE__)
-__attribute__((visibility("protected")))
+    __attribute__((visibility("protected")))
 #endif  // ABSL_HAVE_ATTRIBUTE(visibility) && !defined(__APPLE__)
 #if ABSL_PER_THREAD_TLS
-// Prefer __thread to thread_local as benchmarks indicate it is a bit faster.
-ABSL_PER_THREAD_TLS_KEYWORD ThreadIdentity* thread_identity_ptr = nullptr;
+    // Prefer __thread to thread_local as benchmarks indicate it is a bit
+    // faster.
+    ABSL_PER_THREAD_TLS_KEYWORD ThreadIdentity* thread_identity_ptr = nullptr;
 #elif defined(ABSL_HAVE_THREAD_LOCAL)
-thread_local ThreadIdentity* thread_identity_ptr = nullptr;
+    thread_local ThreadIdentity* thread_identity_ptr = nullptr;
 #endif  // ABSL_PER_THREAD_TLS
 #endif  // TLS or CPP11
 
-void SetCurrentThreadIdentity(
-    ThreadIdentity* identity, ThreadIdentityReclaimerFunction reclaimer) {
+void SetCurrentThreadIdentity(ThreadIdentity* identity,
+                              ThreadIdentityReclaimerFunction reclaimer) {
   assert(CurrentThreadIdentityIfPresent() == nullptr);
   // Associate our destructor.
   // NOTE: This call to pthread_setspecific is currently the only immovable
@@ -134,7 +135,7 @@ void ClearCurrentThreadIdentity() {
     ABSL_THREAD_IDENTITY_MODE == ABSL_THREAD_IDENTITY_MODE_USE_CPP11
   thread_identity_ptr = nullptr;
 #elif ABSL_THREAD_IDENTITY_MODE == \
-      ABSL_THREAD_IDENTITY_MODE_USE_POSIX_SETSPECIFIC
+    ABSL_THREAD_IDENTITY_MODE_USE_POSIX_SETSPECIFIC
   // pthread_setspecific expected to clear value on destruction
   assert(CurrentThreadIdentityIfPresent() == nullptr);
 #endif

third_party/abseil-cpp/absl/base/internal/thread_identity.h

@@ -62,8 +62,8 @@ struct PerThreadSynch {
     return reinterpret_cast<ThreadIdentity*>(this);
   }
 
-  PerThreadSynch *next;  // Circular waiter queue; initialized to 0.
-  PerThreadSynch *skip;  // If non-zero, all entries in Mutex queue
+  PerThreadSynch* next;  // Circular waiter queue; initialized to 0.
+  PerThreadSynch* skip;  // If non-zero, all entries in Mutex queue
                          // up to and including "skip" have same
                          // condition as this, and will be woken later
   bool may_skip;         // if false while on mutex queue, a mutex unlocker
@@ -104,10 +104,7 @@ struct PerThreadSynch {
   //
   // Transitions from kAvailable to kQueued require no barrier, they
   // are externally ordered by the Mutex.
-  enum State {
-    kAvailable,
-    kQueued
-  };
+  enum State { kAvailable, kQueued };
   std::atomic<State> state;
 
   // The wait parameters of the current wait.  waitp is null if the
@@ -122,14 +119,14 @@ struct PerThreadSynch {
   // pointer unchanged.
   SynchWaitParams* waitp;
 
-  intptr_t readers;     // Number of readers in mutex.
+  intptr_t readers;  // Number of readers in mutex.
 
   // When priority will next be read (cycles).
   int64_t next_priority_read_cycles;
 
   // Locks held; used during deadlock detection.
   // Allocated in Synch_GetAllLocks() and freed in ReclaimThreadIdentity().
-  SynchLocksHeld *all_locks;
+  SynchLocksHeld* all_locks;
 };
 
 // The instances of this class are allocated in NewThreadIdentity() with an
@@ -220,7 +217,7 @@ void ClearCurrentThreadIdentity();
 #define ABSL_THREAD_IDENTITY_MODE ABSL_THREAD_IDENTITY_MODE_USE_CPP11
 #elif defined(__APPLE__) && defined(ABSL_HAVE_THREAD_LOCAL)
 #define ABSL_THREAD_IDENTITY_MODE ABSL_THREAD_IDENTITY_MODE_USE_CPP11
-#elif ABSL_PER_THREAD_TLS && defined(__GOOGLE_GRTE_VERSION__) &&        \
+#elif ABSL_PER_THREAD_TLS && defined(__GOOGLE_GRTE_VERSION__) && \
     (__GOOGLE_GRTE_VERSION__ >= 20140228L)
 // Support for async-safe TLS was specifically added in GRTEv4.  It's not
 // present in the upstream eglibc.

third_party/abseil-cpp/absl/base/nullability.h

@@ -0,0 +1,224 @@
+// Copyright 2023 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// -----------------------------------------------------------------------------
+// File: nullability.h
+// -----------------------------------------------------------------------------
+//
+// This header file defines a set of "templated annotations" for designating the
+// expected nullability of pointers. These annotations allow you to designate
+// pointers in one of three classification states:
+//
+//  * "Non-null" (for pointers annotated `NonNull<T>`), indicating that it is
+//    invalid for the given pointer to ever be null.
+//  * "Nullable" (for pointers annotated `Nullable<T>`), indicating that it is
+//    valid for the given pointer to be null.
+//  * "Unknown" (for pointers annotated `NullabilityUnknown<T>`), indicating
+//    that the given pointer has not been yet classified as either nullable or
+//    non-null. This is the default state of unannotated pointers.
+//
+// NOTE: unannotated pointers implicitly bear the annotation
+// `NullabilityUnknown<T>`; you should rarely, if ever, see this annotation used
+// in the codebase explicitly.
+//
+// -----------------------------------------------------------------------------
+// Nullability and Contracts
+// -----------------------------------------------------------------------------
+//
+// These nullability annotations allow you to more clearly specify contracts on
+// software components by narrowing the *preconditions*, *postconditions*, and
+// *invariants* of pointer state(s) in any given interface. It then depends on
+// context who is responsible for fulfilling the annotation's requirements.
+//
+// For example, a function may receive a pointer argument. Designating that
+// pointer argument as "non-null" tightens the precondition of the contract of
+// that function. It is then the responsibility of anyone calling such a
+// function to ensure that the passed pointer is not null.
+//
+// Similarly, a function may have a pointer as a return value. Designating that
+// return value as "non-null" tightens the postcondition of the contract of that
+// function. In this case, however, it is the responsibility of the function
+// itself to ensure that the returned pointer is not null.
+//
+// Clearly defining these contracts allows providers (and consumers) of such
+// pointers to have more confidence in their null state. If a function declares
+// a return value as "non-null", for example, the caller should not need to
+// check whether the returned value is `nullptr`; it can simply assume the
+// pointer is valid.
+//
+// Of course most interfaces already have expectations on the nullability state
+// of pointers, and these expectations are, in effect, a contract; often,
+// however, those contracts are either poorly or partially specified, assumed,
+// or misunderstood. These nullability annotations are designed to allow you to
+// formalize those contracts within the codebase.
+//
+// -----------------------------------------------------------------------------
+// Using Nullability Annotations
+// -----------------------------------------------------------------------------
+//
+// It is important to note that these annotations are not distinct strong
+// *types*. They are alias templates defined to be equal to the underlying
+// pointer type. A pointer annotated `NonNull<T*>`, for example, is simply a
+// pointer of type `T*`. Each annotation acts as a form of documentation about
+// the contract for the given pointer. Each annotation requires providers or
+// consumers of these pointers across API boundaries to take appropriate steps
+// when setting or using these pointers:
+//
+// * "Non-null" pointers should never be null. It is the responsibility of the
+//   provider of this pointer to ensure that the pointer may never be set to
+//   null. Consumers of such pointers can treat such pointers as non-null.
+// * "Nullable" pointers may or may not be null. Consumers of such pointers
+//   should precede any usage of that pointer (e.g. a dereference operation)
+//   with a a `nullptr` check.
+// * "Unknown" pointers may be either "non-null" or "nullable" but have not been
+//   definitively determined to be in either classification state. Providers of
+//   such pointers across API boundaries should determine --  over time -- to
+//   annotate the pointer in either of the above two states. Consumers of such
+//   pointers across an API boundary should continue to treat such pointers as
+//   they currently do.
+//
+// Example:
+//
+// // PaySalary() requires the passed pointer to an `Employee` to be non-null.
+// void PaySalary(absl::NonNull<Employee *> e) {
+//   pay(e->salary);  // OK to dereference
+// }
+//
+// // CompleteTransaction() guarantees the returned pointer to an `Account` to
+// // be non-null.
+// absl::NonNull<Account *> balance CompleteTransaction(double fee) {
+// ...
+// }
+//
+// // Note that specifying a nullability annotation does not prevent someone
+// // from violating the contract:
+//
+// Nullable<Employee *> find(Map& employees, std::string_view name);
+//
+// void g(Map& employees) {
+//   Employee *e = find(employees, "Pat");
+//   // `e` can now be null.
+//   PaySalary(e); // Violates contract, but compiles!
+// }
+//
+// Nullability annotations, in other words, are useful for defining and
+// narrowing contracts; *enforcement* of those contracts depends on use and any
+// additional (static or dynamic analysis) tooling.
+//
+// NOTE: The "unknown" annotation state indicates that a pointer's contract has
+// not yet been positively identified. The unknown state therefore acts as a
+// form of documentation of your technical debt, and a codebase that adopts
+// nullability annotations should aspire to annotate every pointer as either
+// "non-null" or "nullable".
+//
+// -----------------------------------------------------------------------------
+// Applicability of Nullability Annotations
+// -----------------------------------------------------------------------------
+//
+// By default, nullability annotations are applicable to raw and smart
+// pointers. User-defined types can indicate compatibility with nullability
+// annotations by providing an `absl_nullability_compatible` nested type. The
+// actual definition of this inner type is not relevant as it is used merely as
+// a marker. It is common to use a using declaration of
+// `absl_nullability_compatible` set to void.
+//
+// // Example:
+// struct MyPtr {
+//   using absl_nullability_compatible = void;
+//   ...
+// };
+//
+// DISCLAIMER:
+// ===========================================================================
+// These nullability annotations are primarily a human readable signal about the
+// intended contract of the pointer. They are not *types* and do not currently
+// provide any correctness guarantees. For example, a pointer annotated as
+// `NonNull<T*>` is *not guaranteed* to be non-null, and the compiler won't
+// alert or prevent assignment of a `Nullable<T*>` to a `NonNull<T*>`.
+// ===========================================================================
+#ifndef ABSL_BASE_NULLABILITY_H_
+#define ABSL_BASE_NULLABILITY_H_
+
+#include "absl/base/internal/nullability_impl.h"
+
+namespace absl {
+
+// absl::NonNull
+//
+// The indicated pointer is never null. It is the responsibility of the provider
+// of this pointer across an API boundary to ensure that the pointer is never be
+// set to null. Consumers of this pointer across an API boundary may safely
+// dereference the pointer.
+//
+// Example:
+//
+// // `employee` is designated as not null.
+// void PaySalary(absl::NotNull<Employee *> employee) {
+//   pay(*employee);  // OK to dereference
+// }
+template <typename T>
+using NonNull = nullability_internal::NonNullImpl<T>;
+
+// absl::Nullable
+//
+// The indicated pointer may, by design, be either null or non-null. Consumers
+// of this pointer across an API boundary should perform a `nullptr` check
+// before performing any operation using the pointer.
+//
+// Example:
+//
+// // `employee` may  be null.
+// void PaySalary(absl::Nullable<Employee *> employee) {
+//   if (employee != nullptr) {
+//     Pay(*employee);  // OK to dereference
+//   }
+// }
+template <typename T>
+using Nullable = nullability_internal::NullableImpl<T>;
+
+// absl::NullabilityUnknown (default)
+//
+// The indicated pointer has not yet been determined to be definitively
+// "non-null" or "nullable." Providers of such pointers across API boundaries
+// should, over time, annotate such pointers as either "non-null" or "nullable."
+// Consumers of these pointers across an API boundary should treat such pointers
+// with the same caution they treat currently unannotated pointers. Most
+// existing code will have "unknown"  pointers, which should eventually be
+// migrated into one of the above two nullability states: `NonNull<T>` or
+//  `Nullable<T>`.
+//
+// NOTE: Because this annotation is the global default state, pointers without
+// any annotation are assumed to have "unknown" semantics. This assumption is
+// designed to minimize churn and reduce clutter within the codebase.
+//
+// Example:
+//
+// // `employee`s nullability state is unknown.
+// void PaySalary(absl::NullabilityUnknown<Employee *> employee) {
+//   Pay(*employee); // Potentially dangerous. API provider should investigate.
+// }
+//
+// Note that a pointer without an annotation, by default, is assumed to have the
+// annotation `NullabilityUnknown`.
+//
+// // `employee`s nullability state is unknown.
+// void PaySalary(Employee* employee) {
+//   Pay(*employee); // Potentially dangerous. API provider should investigate.
+// }
+template <typename T>
+using NullabilityUnknown = nullability_internal::NullabilityUnknownImpl<T>;
+
+}  // namespace absl
+
+#endif  // ABSL_BASE_NULLABILITY_H_

third_party/abseil-cpp/absl/base/nullability_test.cc

@@ -0,0 +1,129 @@
+// Copyright 2023 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/base/nullability.h"
+
+#include <cassert>
+#include <memory>
+#include <utility>
+
+#include "gtest/gtest.h"
+#include "absl/base/attributes.h"
+
+namespace {
+using ::absl::NonNull;
+using ::absl::NullabilityUnknown;
+using ::absl::Nullable;
+
+void funcWithNonnullArg(NonNull<int*> /*arg*/) {}
+template <typename T>
+void funcWithDeducedNonnullArg(NonNull<T*> /*arg*/) {}
+
+TEST(NonNullTest, NonNullArgument) {
+  int var = 0;
+  funcWithNonnullArg(&var);
+  funcWithDeducedNonnullArg(&var);
+}
+
+NonNull<int*> funcWithNonnullReturn() {
+  static int var = 0;
+  return &var;
+}
+
+TEST(NonNullTest, NonNullReturn) {
+  auto var = funcWithNonnullReturn();
+  (void)var;
+}
+
+TEST(PassThroughTest, PassesThroughRawPointerToInt) {
+  EXPECT_TRUE((std::is_same<NonNull<int*>, int*>::value));
+  EXPECT_TRUE((std::is_same<Nullable<int*>, int*>::value));
+  EXPECT_TRUE((std::is_same<NullabilityUnknown<int*>, int*>::value));
+}
+
+TEST(PassThroughTest, PassesThroughRawPointerToVoid) {
+  EXPECT_TRUE((std::is_same<NonNull<void*>, void*>::value));
+  EXPECT_TRUE((std::is_same<Nullable<void*>, void*>::value));
+  EXPECT_TRUE((std::is_same<NullabilityUnknown<void*>, void*>::value));
+}
+
+TEST(PassThroughTest, PassesThroughUniquePointerToInt) {
+  using T = std::unique_ptr<int>;
+  EXPECT_TRUE((std::is_same<NonNull<T>, T>::value));
+  EXPECT_TRUE((std::is_same<Nullable<T>, T>::value));
+  EXPECT_TRUE((std::is_same<NullabilityUnknown<T>, T>::value));
+}
+
+TEST(PassThroughTest, PassesThroughSharedPointerToInt) {
+  using T = std::shared_ptr<int>;
+  EXPECT_TRUE((std::is_same<NonNull<T>, T>::value));
+  EXPECT_TRUE((std::is_same<Nullable<T>, T>::value));
+  EXPECT_TRUE((std::is_same<NullabilityUnknown<T>, T>::value));
+}
+
+TEST(PassThroughTest, PassesThroughSharedPointerToVoid) {
+  using T = std::shared_ptr<void>;
+  EXPECT_TRUE((std::is_same<NonNull<T>, T>::value));
+  EXPECT_TRUE((std::is_same<Nullable<T>, T>::value));
+  EXPECT_TRUE((std::is_same<NullabilityUnknown<T>, T>::value));
+}
+
+TEST(PassThroughTest, PassesThroughPointerToMemberObject) {
+  using T = decltype(&std::pair<int, int>::first);
+  EXPECT_TRUE((std::is_same<NonNull<T>, T>::value));
+  EXPECT_TRUE((std::is_same<Nullable<T>, T>::value));
+  EXPECT_TRUE((std::is_same<NullabilityUnknown<T>, T>::value));
+}
+
+TEST(PassThroughTest, PassesThroughPointerToMemberFunction) {
+  using T = decltype(&std::unique_ptr<int>::reset);
+  EXPECT_TRUE((std::is_same<NonNull<T>, T>::value));
+  EXPECT_TRUE((std::is_same<Nullable<T>, T>::value));
+  EXPECT_TRUE((std::is_same<NullabilityUnknown<T>, T>::value));
+}
+
+}  // namespace
+
+// Nullable ADL lookup test
+namespace util {
+// Helper for NullableAdlTest.  Returns true, denoting that argument-dependent
+// lookup found this implementation of DidAdlWin.  Must be in namespace
+// util itself, not a nested anonymous namespace.
+template <typename T>
+bool DidAdlWin(T*) {
+  return true;
+}
+
+// Because this type is defined in namespace util, an unqualified call to
+// DidAdlWin with a pointer to MakeAdlWin will find the above implementation.
+struct MakeAdlWin {};
+}  // namespace util
+
+namespace {
+// Returns false, denoting that ADL did not inspect namespace util.  If it
+// had, the better match (T*) above would have won out over the (...) here.
+bool DidAdlWin(...) { return false; }
+
+TEST(NullableAdlTest, NullableAddsNothingToArgumentDependentLookup) {
+  // Treatment: util::Nullable<int*> contributes nothing to ADL because
+  // int* itself doesn't.
+  EXPECT_FALSE(DidAdlWin((int*)nullptr));
+  EXPECT_FALSE(DidAdlWin((Nullable<int*>)nullptr));
+
+  // Control: Argument-dependent lookup does find the implementation in
+  // namespace util when the underlying pointee type resides there.
+  EXPECT_TRUE(DidAdlWin((util::MakeAdlWin*)nullptr));
+  EXPECT_TRUE(DidAdlWin((Nullable<util::MakeAdlWin*>)nullptr));
+}
+}  // namespace

third_party/abseil-cpp/absl/debugging/internal/stacktrace_aarch64-inl.inc

@@ -13,6 +13,7 @@
 #include <cassert>
 #include <cstdint>
 #include <iostream>
+#include <limits>
 
 #include "absl/base/attributes.h"
 #include "absl/debugging/internal/address_is_readable.h"

third_party/abseil-cpp/absl/meta/type_traits.h

@@ -500,8 +500,12 @@ using swap_internal::StdSwapIsUnconstrained;
 // there.
 //
 // TODO(b/275003464): remove the opt-out once the bug is fixed.
-#if ABSL_HAVE_BUILTIN(__is_trivially_relocatable) && \
-    !(defined(__clang__) && (defined(_WIN32) || defined(_WIN64)))
+//
+// According to https://github.com/abseil/abseil-cpp/issues/1479, this does not
+// work with NVCC either.
+#if ABSL_HAVE_BUILTIN(__is_trivially_relocatable) &&                 \
+    !(defined(__clang__) && (defined(_WIN32) || defined(_WIN64))) && \
+    !defined(__NVCC__)
 template <class T>
 struct is_trivially_relocatable
     : std::integral_constant<bool, __is_trivially_relocatable(T)> {};

third_party/abseil-cpp/absl/random/internal/randen_benchmarks.cc

@@ -47,8 +47,10 @@ static constexpr size_t kSeedSizeT = Randen::kSeedBytes / sizeof(uint32_t);
 // Randen implementation benchmarks.
 template <typename T>
 struct AbsorbFn : public T {
-  mutable uint64_t state[kStateSizeT] = {};
-  mutable uint32_t seed[kSeedSizeT] = {};
+  // These are both cast to uint128* in the RandenHwAes implementation, so
+  // ensure they are 16 byte aligned.
+  alignas(16) mutable uint64_t state[kStateSizeT] = {};
+  alignas(16) mutable uint32_t seed[kSeedSizeT] = {};
 
   static constexpr size_t bytes() { return sizeof(seed); }
 

third_party/abseil-cpp/absl/synchronization/internal/create_thread_identity.cc

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include <stdint.h>
+
 #include <new>
 
 // This file is a no-op if the required LowLevelAlloc support is missing.

third_party/abseil-cpp/absl/synchronization/mutex.h

@@ -141,8 +141,9 @@ struct SynchWaitParams;
 // issues that could potentially result in race conditions and deadlocks.
 //
 // For more information about the lock annotations, please see
-// [Thread Safety Analysis](http://clang.llvm.org/docs/ThreadSafetyAnalysis.html)
-// in the Clang documentation.
+// [Thread Safety
+// Analysis](http://clang.llvm.org/docs/ThreadSafetyAnalysis.html) in the Clang
+// documentation.
 //
 // See also `MutexLock`, below, for scoped `Mutex` acquisition.
 
@@ -323,7 +324,7 @@ class ABSL_LOCKABLE Mutex {
   // `true`, `Await()` *may* skip the release/re-acquire step.
   //
   // `Await()` requires that this thread holds this `Mutex` in some mode.
-  void Await(const Condition &cond);
+  void Await(const Condition& cond);
 
   // Mutex::LockWhen()
   // Mutex::ReaderLockWhen()
@@ -333,11 +334,11 @@ class ABSL_LOCKABLE Mutex {
   // be acquired, then atomically acquires this `Mutex`. `LockWhen()` is
   // logically equivalent to `*Lock(); Await();` though they may have different
   // performance characteristics.
-  void LockWhen(const Condition &cond) ABSL_EXCLUSIVE_LOCK_FUNCTION();
+  void LockWhen(const Condition& cond) ABSL_EXCLUSIVE_LOCK_FUNCTION();
 
-  void ReaderLockWhen(const Condition &cond) ABSL_SHARED_LOCK_FUNCTION();
+  void ReaderLockWhen(const Condition& cond) ABSL_SHARED_LOCK_FUNCTION();
 
-  void WriterLockWhen(const Condition &cond) ABSL_EXCLUSIVE_LOCK_FUNCTION() {
+  void WriterLockWhen(const Condition& cond) ABSL_EXCLUSIVE_LOCK_FUNCTION() {
     this->LockWhen(cond);
   }
 
@@ -362,9 +363,9 @@ class ABSL_LOCKABLE Mutex {
   // Negative timeouts are equivalent to a zero timeout.
   //
   // This method requires that this thread holds this `Mutex` in some mode.
-  bool AwaitWithTimeout(const Condition &cond, absl::Duration timeout);
+  bool AwaitWithTimeout(const Condition& cond, absl::Duration timeout);
 
-  bool AwaitWithDeadline(const Condition &cond, absl::Time deadline);
+  bool AwaitWithDeadline(const Condition& cond, absl::Time deadline);
 
   // Mutex::LockWhenWithTimeout()
   // Mutex::ReaderLockWhenWithTimeout()
@@ -377,11 +378,11 @@ class ABSL_LOCKABLE Mutex {
   // `true` on return.
   //
   // Negative timeouts are equivalent to a zero timeout.
-  bool LockWhenWithTimeout(const Condition &cond, absl::Duration timeout)
+  bool LockWhenWithTimeout(const Condition& cond, absl::Duration timeout)
       ABSL_EXCLUSIVE_LOCK_FUNCTION();
-  bool ReaderLockWhenWithTimeout(const Condition &cond, absl::Duration timeout)
+  bool ReaderLockWhenWithTimeout(const Condition& cond, absl::Duration timeout)
       ABSL_SHARED_LOCK_FUNCTION();
-  bool WriterLockWhenWithTimeout(const Condition &cond, absl::Duration timeout)
+  bool WriterLockWhenWithTimeout(const Condition& cond, absl::Duration timeout)
       ABSL_EXCLUSIVE_LOCK_FUNCTION() {
     return this->LockWhenWithTimeout(cond, timeout);
   }
@@ -397,11 +398,11 @@ class ABSL_LOCKABLE Mutex {
   // on return.
   //
   // Deadlines in the past are equivalent to an immediate deadline.
-  bool LockWhenWithDeadline(const Condition &cond, absl::Time deadline)
+  bool LockWhenWithDeadline(const Condition& cond, absl::Time deadline)
       ABSL_EXCLUSIVE_LOCK_FUNCTION();
-  bool ReaderLockWhenWithDeadline(const Condition &cond, absl::Time deadline)
+  bool ReaderLockWhenWithDeadline(const Condition& cond, absl::Time deadline)
       ABSL_SHARED_LOCK_FUNCTION();
-  bool WriterLockWhenWithDeadline(const Condition &cond, absl::Time deadline)
+  bool WriterLockWhenWithDeadline(const Condition& cond, absl::Time deadline)
       ABSL_EXCLUSIVE_LOCK_FUNCTION() {
     return this->LockWhenWithDeadline(cond, deadline);
   }
@@ -423,7 +424,7 @@ class ABSL_LOCKABLE Mutex {
   // substantially reduce `Mutex` performance; it should be set only for
   // non-production runs.  Optimization options may also disable invariant
   // checks.
-  void EnableInvariantDebugging(void (*invariant)(void *), void *arg);
+  void EnableInvariantDebugging(void (*invariant)(void*), void* arg);
 
   // Mutex::EnableDebugLog()
   //
@@ -432,7 +433,7 @@ class ABSL_LOCKABLE Mutex {
   // call to `EnableInvariantDebugging()` or `EnableDebugLog()` has been made.
   //
   // Note: This method substantially reduces `Mutex` performance.
-  void EnableDebugLog(const char *name);
+  void EnableDebugLog(const char* name);
 
   // Deadlock detection
 
@@ -460,7 +461,7 @@ class ABSL_LOCKABLE Mutex {
 
   // A `MuHow` is a constant that indicates how a lock should be acquired.
   // Internal implementation detail.  Clients should ignore.
-  typedef const struct MuHowS *MuHow;
+  typedef const struct MuHowS* MuHow;
 
   // Mutex::InternalAttemptToUseMutexInFatalSignalHandler()
   //
@@ -482,37 +483,37 @@ class ABSL_LOCKABLE Mutex {
 
   // Post()/Wait() versus associated PerThreadSem; in class for required
   // friendship with PerThreadSem.
-  static void IncrementSynchSem(Mutex *mu, base_internal::PerThreadSynch *w);
-  static bool DecrementSynchSem(Mutex *mu, base_internal::PerThreadSynch *w,
+  static void IncrementSynchSem(Mutex* mu, base_internal::PerThreadSynch* w);
+  static bool DecrementSynchSem(Mutex* mu, base_internal::PerThreadSynch* w,
                                 synchronization_internal::KernelTimeout t);
 
   // slow path acquire
-  void LockSlowLoop(SynchWaitParams *waitp, int flags);
+  void LockSlowLoop(SynchWaitParams* waitp, int flags);
   // wrappers around LockSlowLoop()
-  bool LockSlowWithDeadline(MuHow how, const Condition *cond,
+  bool LockSlowWithDeadline(MuHow how, const Condition* cond,
                             synchronization_internal::KernelTimeout t,
                             int flags);
-  void LockSlow(MuHow how, const Condition *cond,
+  void LockSlow(MuHow how, const Condition* cond,
                 int flags) ABSL_ATTRIBUTE_COLD;
   // slow path release
-  void UnlockSlow(SynchWaitParams *waitp) ABSL_ATTRIBUTE_COLD;
+  void UnlockSlow(SynchWaitParams* waitp) ABSL_ATTRIBUTE_COLD;
   // Common code between Await() and AwaitWithTimeout/Deadline()
-  bool AwaitCommon(const Condition &cond,
+  bool AwaitCommon(const Condition& cond,
                    synchronization_internal::KernelTimeout t);
   // Attempt to remove thread s from queue.
-  void TryRemove(base_internal::PerThreadSynch *s);
+  void TryRemove(base_internal::PerThreadSynch* s);
   // Block a thread on mutex.
-  void Block(base_internal::PerThreadSynch *s);
+  void Block(base_internal::PerThreadSynch* s);
   // Wake a thread; return successor.
-  base_internal::PerThreadSynch *Wakeup(base_internal::PerThreadSynch *w);
+  base_internal::PerThreadSynch* Wakeup(base_internal::PerThreadSynch* w);
 
   friend class CondVar;   // for access to Trans()/Fer().
   void Trans(MuHow how);  // used for CondVar->Mutex transfer
   void Fer(
-      base_internal::PerThreadSynch *w);  // used for CondVar->Mutex transfer
+      base_internal::PerThreadSynch* w);  // used for CondVar->Mutex transfer
 
   // Catch the error of writing Mutex when intending MutexLock.
-  Mutex(const volatile Mutex * /*ignored*/) {}  // NOLINT(runtime/explicit)
+  explicit Mutex(const volatile Mutex* /*ignored*/) {}
 
   Mutex(const Mutex&) = delete;
   Mutex& operator=(const Mutex&) = delete;
@@ -547,28 +548,28 @@ class ABSL_SCOPED_LOCKABLE MutexLock {
   // Calls `mu->Lock()` and returns when that call returns. That is, `*mu` is
   // guaranteed to be locked when this object is constructed. Requires that
   // `mu` be dereferenceable.
-  explicit MutexLock(Mutex *mu) ABSL_EXCLUSIVE_LOCK_FUNCTION(mu) : mu_(mu) {
+  explicit MutexLock(Mutex* mu) ABSL_EXCLUSIVE_LOCK_FUNCTION(mu) : mu_(mu) {
     this->mu_->Lock();
   }
 
   // Like above, but calls `mu->LockWhen(cond)` instead. That is, in addition to
   // the above, the condition given by `cond` is also guaranteed to hold when
   // this object is constructed.
-  explicit MutexLock(Mutex *mu, const Condition &cond)
+  explicit MutexLock(Mutex* mu, const Condition& cond)
       ABSL_EXCLUSIVE_LOCK_FUNCTION(mu)
       : mu_(mu) {
     this->mu_->LockWhen(cond);
   }
 
-  MutexLock(const MutexLock &) = delete;  // NOLINT(runtime/mutex)
-  MutexLock(MutexLock&&) = delete;  // NOLINT(runtime/mutex)
+  MutexLock(const MutexLock&) = delete;  // NOLINT(runtime/mutex)
+  MutexLock(MutexLock&&) = delete;       // NOLINT(runtime/mutex)
   MutexLock& operator=(const MutexLock&) = delete;
   MutexLock& operator=(MutexLock&&) = delete;
 
   ~MutexLock() ABSL_UNLOCK_FUNCTION() { this->mu_->Unlock(); }
 
  private:
-  Mutex *const mu_;
+  Mutex* const mu_;
 };
 
 // ReaderMutexLock
@@ -577,11 +578,11 @@ class ABSL_SCOPED_LOCKABLE MutexLock {
 // releases a shared lock on a `Mutex` via RAII.
 class ABSL_SCOPED_LOCKABLE ReaderMutexLock {
  public:
-  explicit ReaderMutexLock(Mutex *mu) ABSL_SHARED_LOCK_FUNCTION(mu) : mu_(mu) {
+  explicit ReaderMutexLock(Mutex* mu) ABSL_SHARED_LOCK_FUNCTION(mu) : mu_(mu) {
     mu->ReaderLock();
   }
 
-  explicit ReaderMutexLock(Mutex *mu, const Condition &cond)
+  explicit ReaderMutexLock(Mutex* mu, const Condition& cond)
       ABSL_SHARED_LOCK_FUNCTION(mu)
       : mu_(mu) {
     mu->ReaderLockWhen(cond);
@@ -595,7 +596,7 @@ class ABSL_SCOPED_LOCKABLE ReaderMutexLock {
   ~ReaderMutexLock() ABSL_UNLOCK_FUNCTION() { this->mu_->ReaderUnlock(); }
 
  private:
-  Mutex *const mu_;
+  Mutex* const mu_;
 };
 
 // WriterMutexLock
@@ -604,12 +605,12 @@ class ABSL_SCOPED_LOCKABLE ReaderMutexLock {
 // releases a write (exclusive) lock on a `Mutex` via RAII.
 class ABSL_SCOPED_LOCKABLE WriterMutexLock {
  public:
-  explicit WriterMutexLock(Mutex *mu) ABSL_EXCLUSIVE_LOCK_FUNCTION(mu)
+  explicit WriterMutexLock(Mutex* mu) ABSL_EXCLUSIVE_LOCK_FUNCTION(mu)
       : mu_(mu) {
     mu->WriterLock();
   }
 
-  explicit WriterMutexLock(Mutex *mu, const Condition &cond)
+  explicit WriterMutexLock(Mutex* mu, const Condition& cond)
       ABSL_EXCLUSIVE_LOCK_FUNCTION(mu)
       : mu_(mu) {
     mu->WriterLockWhen(cond);
@@ -623,7 +624,7 @@ class ABSL_SCOPED_LOCKABLE WriterMutexLock {
   ~WriterMutexLock() ABSL_UNLOCK_FUNCTION() { this->mu_->WriterUnlock(); }
 
  private:
-  Mutex *const mu_;
+  Mutex* const mu_;
 };
 
 // -----------------------------------------------------------------------------
@@ -681,7 +682,7 @@ class ABSL_SCOPED_LOCKABLE WriterMutexLock {
 class Condition {
  public:
   // A Condition that returns the result of "(*func)(arg)"
-  Condition(bool (*func)(void *), void *arg);
+  Condition(bool (*func)(void*), void* arg);
 
   // Templated version for people who are averse to casts.
   //
@@ -692,8 +693,8 @@ class Condition {
   // Note: lambdas in this case must contain no bound variables.
   //
   // See class comment for performance advice.
-  template<typename T>
-  Condition(bool (*func)(T *), T *arg);
+  template <typename T>
+  Condition(bool (*func)(T*), T* arg);
 
   // Same as above, but allows for cases where `arg` comes from a pointer that
   // is convertible to the function parameter type `T*` but not an exact match.
@@ -707,7 +708,7 @@ class Condition {
   // a function template is passed as `func`. Also, the dummy `typename = void`
   // template parameter exists just to work around a MSVC mangling bug.
   template <typename T, typename = void>
-  Condition(bool (*func)(T *), typename absl::internal::identity<T>::type *arg);
+  Condition(bool (*func)(T*), typename absl::internal::identity<T>::type* arg);
 
   // Templated version for invoking a method that returns a `bool`.
   //
@@ -717,16 +718,16 @@ class Condition {
   // Implementation Note: `absl::internal::identity` is used to allow methods to
   // come from base classes. A simpler signature like
   // `Condition(T*, bool (T::*)())` does not suffice.
-  template<typename T>
-  Condition(T *object, bool (absl::internal::identity<T>::type::* method)());
+  template <typename T>
+  Condition(T* object, bool (absl::internal::identity<T>::type::*method)());
 
   // Same as above, for const members
-  template<typename T>
-  Condition(const T *object,
-            bool (absl::internal::identity<T>::type::* method)() const);
+  template <typename T>
+  Condition(const T* object,
+            bool (absl::internal::identity<T>::type::*method)() const);
 
   // A Condition that returns the value of `*cond`
-  explicit Condition(const bool *cond);
+  explicit Condition(const bool* cond);
 
   // Templated version for invoking a functor that returns a `bool`.
   // This approach accepts pointers to non-mutable lambdas, `std::function`,
@@ -753,9 +754,9 @@ class Condition {
   // Implementation note: The second template parameter ensures that this
   // constructor doesn't participate in overload resolution if T doesn't have
   // `bool operator() const`.
-  template <typename T, typename E = decltype(
-      static_cast<bool (T::*)() const>(&T::operator()))>
-  explicit Condition(const T *obj)
+  template <typename T, typename E = decltype(static_cast<bool (T::*)() const>(
+                            &T::operator()))>
+  explicit Condition(const T* obj)
       : Condition(obj, static_cast<bool (T::*)() const>(&T::operator())) {}
 
   // A Condition that always returns `true`.
@@ -771,7 +772,7 @@ class Condition {
   // Two `Condition` values are guaranteed equal if both their `func` and `arg`
   // components are the same. A null pointer is equivalent to a `true`
   // condition.
-  static bool GuaranteedEqual(const Condition *a, const Condition *b);
+  static bool GuaranteedEqual(const Condition* a, const Condition* b);
 
  private:
   // Sizing an allocation for a method pointer can be subtle. In the Itanium
@@ -799,12 +800,14 @@ class Condition {
   bool (*eval_)(const Condition*) = nullptr;
 
   // Either an argument for a function call or an object for a method call.
-  void *arg_ = nullptr;
+  void* arg_ = nullptr;
 
   // Various functions eval_ can point to:
   static bool CallVoidPtrFunction(const Condition*);
-  template <typename T> static bool CastAndCallFunction(const Condition* c);
-  template <typename T> static bool CastAndCallMethod(const Condition* c);
+  template <typename T>
+  static bool CastAndCallFunction(const Condition* c);
+  template <typename T>
+  static bool CastAndCallMethod(const Condition* c);
 
   // Helper methods for storing, validating, and reading callback arguments.
   template <typename T>
@@ -816,7 +819,7 @@ class Condition {
   }
 
   template <typename T>
-  inline void ReadCallback(T *callback) const {
+  inline void ReadCallback(T* callback) const {
     std::memcpy(callback, callback_, sizeof(*callback));
   }
 
@@ -873,7 +876,7 @@ class CondVar {
   // spurious wakeup), then reacquires the `Mutex` and returns.
   //
   // Requires and ensures that the current thread holds the `Mutex`.
-  void Wait(Mutex *mu);
+  void Wait(Mutex* mu);
 
   // CondVar::WaitWithTimeout()
   //
@@ -888,7 +891,7 @@ class CondVar {
   // to return `true` or `false`.
   //
   // Requires and ensures that the current thread holds the `Mutex`.
-  bool WaitWithTimeout(Mutex *mu, absl::Duration timeout);
+  bool WaitWithTimeout(Mutex* mu, absl::Duration timeout);
 
   // CondVar::WaitWithDeadline()
   //
@@ -905,7 +908,7 @@ class CondVar {
   // to return `true` or `false`.
   //
   // Requires and ensures that the current thread holds the `Mutex`.
-  bool WaitWithDeadline(Mutex *mu, absl::Time deadline);
+  bool WaitWithDeadline(Mutex* mu, absl::Time deadline);
 
   // CondVar::Signal()
   //
@@ -922,18 +925,17 @@ class CondVar {
   // Causes all subsequent uses of this `CondVar` to be logged via
   // `ABSL_RAW_LOG(INFO)`. Log entries are tagged with `name` if `name != 0`.
   // Note: this method substantially reduces `CondVar` performance.
-  void EnableDebugLog(const char *name);
+  void EnableDebugLog(const char* name);
 
  private:
-  bool WaitCommon(Mutex *mutex, synchronization_internal::KernelTimeout t);
-  void Remove(base_internal::PerThreadSynch *s);
-  void Wakeup(base_internal::PerThreadSynch *w);
+  bool WaitCommon(Mutex* mutex, synchronization_internal::KernelTimeout t);
+  void Remove(base_internal::PerThreadSynch* s);
+  void Wakeup(base_internal::PerThreadSynch* w);
   std::atomic<intptr_t> cv_;  // Condition variable state.
   CondVar(const CondVar&) = delete;
   CondVar& operator=(const CondVar&) = delete;
 };
 
-
 // Variants of MutexLock.
 //
 // If you find yourself using one of these, consider instead using
@@ -944,14 +946,14 @@ class CondVar {
 // MutexLockMaybe is like MutexLock, but is a no-op when mu is null.
 class ABSL_SCOPED_LOCKABLE MutexLockMaybe {
  public:
-  explicit MutexLockMaybe(Mutex *mu) ABSL_EXCLUSIVE_LOCK_FUNCTION(mu)
+  explicit MutexLockMaybe(Mutex* mu) ABSL_EXCLUSIVE_LOCK_FUNCTION(mu)
       : mu_(mu) {
     if (this->mu_ != nullptr) {
       this->mu_->Lock();
     }
   }
 
-  explicit MutexLockMaybe(Mutex *mu, const Condition &cond)
+  explicit MutexLockMaybe(Mutex* mu, const Condition& cond)
       ABSL_EXCLUSIVE_LOCK_FUNCTION(mu)
       : mu_(mu) {
     if (this->mu_ != nullptr) {
@@ -960,11 +962,13 @@ class ABSL_SCOPED_LOCKABLE MutexLockMaybe {
   }
 
   ~MutexLockMaybe() ABSL_UNLOCK_FUNCTION() {
-    if (this->mu_ != nullptr) { this->mu_->Unlock(); }
+    if (this->mu_ != nullptr) {
+      this->mu_->Unlock();
+    }
   }
 
  private:
-  Mutex *const mu_;
+  Mutex* const mu_;
   MutexLockMaybe(const MutexLockMaybe&) = delete;
   MutexLockMaybe(MutexLockMaybe&&) = delete;
   MutexLockMaybe& operator=(const MutexLockMaybe&) = delete;
@@ -977,25 +981,27 @@ class ABSL_SCOPED_LOCKABLE MutexLockMaybe {
 // mutex before destruction. `Release()` may be called at most once.
 class ABSL_SCOPED_LOCKABLE ReleasableMutexLock {
  public:
-  explicit ReleasableMutexLock(Mutex *mu) ABSL_EXCLUSIVE_LOCK_FUNCTION(mu)
+  explicit ReleasableMutexLock(Mutex* mu) ABSL_EXCLUSIVE_LOCK_FUNCTION(mu)
       : mu_(mu) {
     this->mu_->Lock();
   }
 
-  explicit ReleasableMutexLock(Mutex *mu, const Condition &cond)
+  explicit ReleasableMutexLock(Mutex* mu, const Condition& cond)
       ABSL_EXCLUSIVE_LOCK_FUNCTION(mu)
       : mu_(mu) {
     this->mu_->LockWhen(cond);
   }
 
   ~ReleasableMutexLock() ABSL_UNLOCK_FUNCTION() {
-    if (this->mu_ != nullptr) { this->mu_->Unlock(); }
+    if (this->mu_ != nullptr) {
+      this->mu_->Unlock();
+    }
   }
 
   void Release() ABSL_UNLOCK_FUNCTION();
 
  private:
-  Mutex *mu_;
+  Mutex* mu_;
   ReleasableMutexLock(const ReleasableMutexLock&) = delete;
   ReleasableMutexLock(ReleasableMutexLock&&) = delete;
   ReleasableMutexLock& operator=(const ReleasableMutexLock&) = delete;
@@ -1012,8 +1018,8 @@ inline CondVar::CondVar() : cv_(0) {}
 
 // static
 template <typename T>
-bool Condition::CastAndCallMethod(const Condition *c) {
-  T *object = static_cast<T *>(c->arg_);
+bool Condition::CastAndCallMethod(const Condition* c) {
+  T* object = static_cast<T*>(c->arg_);
   bool (T::*method_pointer)();
   c->ReadCallback(&method_pointer);
   return (object->*method_pointer)();
@@ -1021,44 +1027,43 @@ bool Condition::CastAndCallMethod(const Condition *c) {
 
 // static
 template <typename T>
-bool Condition::CastAndCallFunction(const Condition *c) {
-  bool (*function)(T *);
+bool Condition::CastAndCallFunction(const Condition* c) {
+  bool (*function)(T*);
   c->ReadCallback(&function);
-  T *argument = static_cast<T *>(c->arg_);
+  T* argument = static_cast<T*>(c->arg_);
   return (*function)(argument);
 }
 
 template <typename T>
-inline Condition::Condition(bool (*func)(T *), T *arg)
+inline Condition::Condition(bool (*func)(T*), T* arg)
     : eval_(&CastAndCallFunction<T>),
-      arg_(const_cast<void *>(static_cast<const void *>(arg))) {
+      arg_(const_cast<void*>(static_cast<const void*>(arg))) {
   static_assert(sizeof(&func) <= sizeof(callback_),
                 "An overlarge function pointer was passed to Condition.");
   StoreCallback(func);
 }
 
 template <typename T, typename>
-inline Condition::Condition(bool (*func)(T *),
-                            typename absl::internal::identity<T>::type *arg)
+inline Condition::Condition(bool (*func)(T*),
+                            typename absl::internal::identity<T>::type* arg)
     // Just delegate to the overload above.
     : Condition(func, arg) {}
 
 template <typename T>
-inline Condition::Condition(T *object,
+inline Condition::Condition(T* object,
                             bool (absl::internal::identity<T>::type::*method)())
-    : eval_(&CastAndCallMethod<T>),
-      arg_(object) {
+    : eval_(&CastAndCallMethod<T>), arg_(object) {
   static_assert(sizeof(&method) <= sizeof(callback_),
                 "An overlarge method pointer was passed to Condition.");
   StoreCallback(method);
 }
 
 template <typename T>
-inline Condition::Condition(const T *object,
+inline Condition::Condition(const T* object,
                             bool (absl::internal::identity<T>::type::*method)()
                                 const)
     : eval_(&CastAndCallMethod<T>),
-      arg_(reinterpret_cast<void *>(const_cast<T *>(object))) {
+      arg_(reinterpret_cast<void*>(const_cast<T*>(object))) {
   StoreCallback(method);
 }
 
@@ -1088,7 +1093,7 @@ void RegisterMutexProfiler(void (*fn)(int64_t wait_cycles));
 //
 // This has the same ordering and single-use limitations as
 // RegisterMutexProfiler() above.
-void RegisterMutexTracer(void (*fn)(const char *msg, const void *obj,
+void RegisterMutexTracer(void (*fn)(const char* msg, const void* obj,
                                     int64_t wait_cycles));
 
 // Register a hook for CondVar tracing.
@@ -1103,7 +1108,7 @@ void RegisterMutexTracer(void (*fn)(const char *msg, const void *obj,
 //
 // This has the same ordering and single-use limitations as
 // RegisterMutexProfiler() above.
-void RegisterCondVarTracer(void (*fn)(const char *msg, const void *cv));
+void RegisterCondVarTracer(void (*fn)(const char* msg, const void* cv));
 
 // EnableMutexInvariantDebugging()
 //
@@ -1120,7 +1125,7 @@ void EnableMutexInvariantDebugging(bool enabled);
 enum class OnDeadlockCycle {
   kIgnore,  // Neither report on nor attempt to track cycles in lock ordering
   kReport,  // Report lock cycles to stderr when detected
-  kAbort,  // Report lock cycles to stderr when detected, then abort
+  kAbort,   // Report lock cycles to stderr when detected, then abort
 };
 
 // SetMutexDeadlockDetectionMode()

third_party/abseil-cpp/absl/synchronization/mutex_test.cc

@@ -1868,4 +1868,29 @@ TEST(Mutex, WriterPriority) {
   EXPECT_TRUE(saw_wrote.load());
 }
 
+TEST(Mutex, LockWhenWithTimeoutResult) {
+  // Check various corner cases for Await/LockWhen return value
+  // with always true/always false conditions.
+  absl::Mutex mu;
+  const bool kAlwaysTrue = true, kAlwaysFalse = false;
+  const absl::Condition kTrueCond(&kAlwaysTrue), kFalseCond(&kAlwaysFalse);
+  EXPECT_TRUE(mu.LockWhenWithTimeout(kTrueCond, absl::Milliseconds(1)));
+  mu.Unlock();
+  EXPECT_FALSE(mu.LockWhenWithTimeout(kFalseCond, absl::Milliseconds(1)));
+  EXPECT_TRUE(mu.AwaitWithTimeout(kTrueCond, absl::Milliseconds(1)));
+  EXPECT_FALSE(mu.AwaitWithTimeout(kFalseCond, absl::Milliseconds(1)));
+  std::thread th1([&]() {
+    EXPECT_TRUE(mu.LockWhenWithTimeout(kTrueCond, absl::Milliseconds(1)));
+    mu.Unlock();
+  });
+  std::thread th2([&]() {
+    EXPECT_FALSE(mu.LockWhenWithTimeout(kFalseCond, absl::Milliseconds(1)));
+    mu.Unlock();
+  });
+  absl::SleepFor(absl::Milliseconds(100));
+  mu.Unlock();
+  th1.join();
+  th2.join();
+}
+
 }  // namespace