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Diffstat (limited to 'absl/base/internal/dynamic_annotations.h')
| -rw-r--r-- | absl/base/internal/dynamic_annotations.h | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/absl/base/internal/dynamic_annotations.h b/absl/base/internal/dynamic_annotations.h new file mode 100644 index 00000000..b23c5ec1 --- /dev/null +++ b/absl/base/internal/dynamic_annotations.h @@ -0,0 +1,398 @@ +// Copyright 2017 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. + +// This file defines dynamic annotations for use with dynamic analysis tool +// such as valgrind, PIN, etc. +// +// Dynamic annotation is a source code annotation that affects the generated +// code (that is, the annotation is not a comment). Each such annotation is +// attached to a particular instruction and/or to a particular object (address) +// in the program. +// +// The annotations that should be used by users are macros in all upper-case +// (e.g., ANNOTATE_THREAD_NAME). +// +// Actual implementation of these macros may differ depending on the dynamic +// analysis tool being used. +// +// This file supports the following configurations: +// - Dynamic Annotations enabled (with static thread-safety warnings disabled). +// In this case, macros expand to functions implemented by Thread Sanitizer, +// when building with TSan. When not provided an external implementation, +// dynamic_annotations.cc provides no-op implementations. +// +// - Static Clang thread-safety warnings enabled. +// When building with a Clang compiler that supports thread-safety warnings, +// a subset of annotations can be statically-checked at compile-time. We +// expand these macros to static-inline functions that can be analyzed for +// thread-safety, but afterwards elided when building the final binary. +// +// - All annotations are disabled. +// If neither Dynamic Annotations nor Clang thread-safety warnings are +// enabled, then all annotation-macros expand to empty. + +#ifndef ABSL_BASE_INTERNAL_DYNAMIC_ANNOTATIONS_H_ +#define ABSL_BASE_INTERNAL_DYNAMIC_ANNOTATIONS_H_ + +#include <stddef.h> + +#include "absl/base/config.h" + +// ------------------------------------------------------------------------- +// Decide which features are enabled + +#ifndef DYNAMIC_ANNOTATIONS_ENABLED +#define DYNAMIC_ANNOTATIONS_ENABLED 0 +#endif + +#if defined(__clang__) && !defined(SWIG) +#define ABSL_INTERNAL_IGNORE_READS_ATTRIBUTE_ENABLED 1 +#endif + +#if DYNAMIC_ANNOTATIONS_ENABLED != 0 + +#define ABSL_INTERNAL_RACE_ANNOTATIONS_ENABLED 1 +#define ABSL_INTERNAL_READS_ANNOTATIONS_ENABLED 1 +#define ABSL_INTERNAL_WRITES_ANNOTATIONS_ENABLED 1 +#define ABSL_INTERNAL_ANNOTALYSIS_ENABLED 0 +#define ABSL_INTERNAL_READS_WRITES_ANNOTATIONS_ENABLED 1 + +#else + +#define ABSL_INTERNAL_RACE_ANNOTATIONS_ENABLED 0 +#define ABSL_INTERNAL_READS_ANNOTATIONS_ENABLED 0 +#define ABSL_INTERNAL_WRITES_ANNOTATIONS_ENABLED 0 + +// Clang provides limited support for static thread-safety analysis through a +// feature called Annotalysis. We configure macro-definitions according to +// whether Annotalysis support is available. When running in opt-mode, GCC +// will issue a warning, if these attributes are compiled. Only include them +// when compiling using Clang. + +// ANNOTALYSIS_ENABLED == 1 when IGNORE_READ_ATTRIBUTE_ENABLED == 1 +#define ABSL_INTERNAL_ANNOTALYSIS_ENABLED \ + defined(ABSL_INTERNAL_IGNORE_READS_ATTRIBUTE_ENABLED) +// Read/write annotations are enabled in Annotalysis mode; disabled otherwise. +#define ABSL_INTERNAL_READS_WRITES_ANNOTATIONS_ENABLED \ + ABSL_INTERNAL_ANNOTALYSIS_ENABLED +#endif + +// Memory annotations are also made available to LLVM's Memory Sanitizer +#if defined(ABSL_HAVE_MEMORY_SANITIZER) && !defined(__native_client__) +#define ABSL_INTERNAL_MEMORY_ANNOTATIONS_ENABLED 1 +#endif + +#ifndef ABSL_INTERNAL_MEMORY_ANNOTATIONS_ENABLED +#define ABSL_INTERNAL_MEMORY_ANNOTATIONS_ENABLED 0 +#endif + +#ifdef __cplusplus +#define ABSL_INTERNAL_BEGIN_EXTERN_C extern "C" { +#define ABSL_INTERNAL_END_EXTERN_C } // extern "C" +#define ABSL_INTERNAL_GLOBAL_SCOPED(F) ::F +#define ABSL_INTERNAL_STATIC_INLINE inline +#else +#define ABSL_INTERNAL_BEGIN_EXTERN_C // empty +#define ABSL_INTERNAL_END_EXTERN_C // empty +#define ABSL_INTERNAL_GLOBAL_SCOPED(F) F +#define ABSL_INTERNAL_STATIC_INLINE static inline +#endif + +// ------------------------------------------------------------------------- +// Define race annotations. + +#if ABSL_INTERNAL_RACE_ANNOTATIONS_ENABLED == 1 + +// ------------------------------------------------------------- +// Annotations that suppress errors. It is usually better to express the +// program's synchronization using the other annotations, but these can be used +// when all else fails. + +// Report that we may have a benign race at `pointer`, with size +// "sizeof(*(pointer))". `pointer` must be a non-void* pointer. Insert at the +// point where `pointer` has been allocated, preferably close to the point +// where the race happens. See also ANNOTATE_BENIGN_RACE_STATIC. +#define ANNOTATE_BENIGN_RACE(pointer, description) \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateBenignRaceSized) \ + (__FILE__, __LINE__, pointer, sizeof(*(pointer)), description) + +// Same as ANNOTATE_BENIGN_RACE(`address`, `description`), but applies to +// the memory range [`address`, `address`+`size`). +#define ANNOTATE_BENIGN_RACE_SIZED(address, size, description) \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateBenignRaceSized) \ + (__FILE__, __LINE__, address, size, description) + +// Enable (`enable`!=0) or disable (`enable`==0) race detection for all threads. +// This annotation could be useful if you want to skip expensive race analysis +// during some period of program execution, e.g. during initialization. +#define ANNOTATE_ENABLE_RACE_DETECTION(enable) \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateEnableRaceDetection) \ + (__FILE__, __LINE__, enable) + +// ------------------------------------------------------------- +// Annotations useful for debugging. + +// Report the current thread `name` to a race detector. +#define ANNOTATE_THREAD_NAME(name) \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateThreadName)(__FILE__, __LINE__, name) + +// ------------------------------------------------------------- +// Annotations useful when implementing locks. They are not normally needed by +// modules that merely use locks. The `lock` argument is a pointer to the lock +// object. + +// Report that a lock has been created at address `lock`. +#define ANNOTATE_RWLOCK_CREATE(lock) \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateRWLockCreate)(__FILE__, __LINE__, lock) + +// Report that a linker initialized lock has been created at address `lock`. +#ifdef ABSL_HAVE_THREAD_SANITIZER +#define ANNOTATE_RWLOCK_CREATE_STATIC(lock) \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateRWLockCreateStatic) \ + (__FILE__, __LINE__, lock) +#else +#define ANNOTATE_RWLOCK_CREATE_STATIC(lock) ANNOTATE_RWLOCK_CREATE(lock) +#endif + +// Report that the lock at address `lock` is about to be destroyed. +#define ANNOTATE_RWLOCK_DESTROY(lock) \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateRWLockDestroy)(__FILE__, __LINE__, lock) + +// Report that the lock at address `lock` has been acquired. +// `is_w`=1 for writer lock, `is_w`=0 for reader lock. +#define ANNOTATE_RWLOCK_ACQUIRED(lock, is_w) \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateRWLockAcquired) \ + (__FILE__, __LINE__, lock, is_w) + +// Report that the lock at address `lock` is about to be released. +// `is_w`=1 for writer lock, `is_w`=0 for reader lock. +#define ANNOTATE_RWLOCK_RELEASED(lock, is_w) \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateRWLockReleased) \ + (__FILE__, __LINE__, lock, is_w) + +// Apply ANNOTATE_BENIGN_RACE_SIZED to a static variable `static_var`. +#define ANNOTATE_BENIGN_RACE_STATIC(static_var, description) \ + namespace { \ + class static_var##_annotator { \ + public: \ + static_var##_annotator() { \ + ANNOTATE_BENIGN_RACE_SIZED(&static_var, sizeof(static_var), \ + #static_var ": " description); \ + } \ + }; \ + static static_var##_annotator the##static_var##_annotator; \ + } // namespace + +#else // ABSL_INTERNAL_RACE_ANNOTATIONS_ENABLED == 0 + +#define ANNOTATE_RWLOCK_CREATE(lock) // empty +#define ANNOTATE_RWLOCK_CREATE_STATIC(lock) // empty +#define ANNOTATE_RWLOCK_DESTROY(lock) // empty +#define ANNOTATE_RWLOCK_ACQUIRED(lock, is_w) // empty +#define ANNOTATE_RWLOCK_RELEASED(lock, is_w) // empty +#define ANNOTATE_BENIGN_RACE(address, description) // empty +#define ANNOTATE_BENIGN_RACE_SIZED(address, size, description) // empty +#define ANNOTATE_THREAD_NAME(name) // empty +#define ANNOTATE_ENABLE_RACE_DETECTION(enable) // empty +#define ANNOTATE_BENIGN_RACE_STATIC(static_var, description) // empty + +#endif // ABSL_INTERNAL_RACE_ANNOTATIONS_ENABLED + +// ------------------------------------------------------------------------- +// Define memory annotations. + +#if ABSL_INTERNAL_MEMORY_ANNOTATIONS_ENABLED == 1 + +#include <sanitizer/msan_interface.h> + +#define ANNOTATE_MEMORY_IS_INITIALIZED(address, size) \ + __msan_unpoison(address, size) + +#define ANNOTATE_MEMORY_IS_UNINITIALIZED(address, size) \ + __msan_allocated_memory(address, size) + +#else // ABSL_INTERNAL_MEMORY_ANNOTATIONS_ENABLED == 0 + +#if DYNAMIC_ANNOTATIONS_ENABLED == 1 +#define ANNOTATE_MEMORY_IS_INITIALIZED(address, size) \ + do { \ + (void)(address); \ + (void)(size); \ + } while (0) +#define ANNOTATE_MEMORY_IS_UNINITIALIZED(address, size) \ + do { \ + (void)(address); \ + (void)(size); \ + } while (0) +#else +#define ANNOTATE_MEMORY_IS_INITIALIZED(address, size) // empty +#define ANNOTATE_MEMORY_IS_UNINITIALIZED(address, size) // empty +#endif + +#endif // ABSL_INTERNAL_MEMORY_ANNOTATIONS_ENABLED + +// ------------------------------------------------------------------------- +// Define IGNORE_READS_BEGIN/_END attributes. + +#if defined(ABSL_INTERNAL_IGNORE_READS_ATTRIBUTE_ENABLED) + +#define ABSL_INTERNAL_IGNORE_READS_BEGIN_ATTRIBUTE \ + __attribute((exclusive_lock_function("*"))) +#define ABSL_INTERNAL_IGNORE_READS_END_ATTRIBUTE \ + __attribute((unlock_function("*"))) + +#else // !defined(ABSL_INTERNAL_IGNORE_READS_ATTRIBUTE_ENABLED) + +#define ABSL_INTERNAL_IGNORE_READS_BEGIN_ATTRIBUTE // empty +#define ABSL_INTERNAL_IGNORE_READS_END_ATTRIBUTE // empty + +#endif // defined(ABSL_INTERNAL_IGNORE_READS_ATTRIBUTE_ENABLED) + +// ------------------------------------------------------------------------- +// Define IGNORE_READS_BEGIN/_END annotations. + +#if ABSL_INTERNAL_READS_ANNOTATIONS_ENABLED == 1 + +// Request the analysis tool to ignore all reads in the current thread until +// ANNOTATE_IGNORE_READS_END is called. Useful to ignore intentional racey +// reads, while still checking other reads and all writes. +// See also ANNOTATE_UNPROTECTED_READ. +#define ANNOTATE_IGNORE_READS_BEGIN() \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateIgnoreReadsBegin)(__FILE__, __LINE__) + +// Stop ignoring reads. +#define ANNOTATE_IGNORE_READS_END() \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateIgnoreReadsEnd)(__FILE__, __LINE__) + +#elif defined(ABSL_INTERNAL_ANNOTALYSIS_ENABLED) + +// When Annotalysis is enabled without Dynamic Annotations, the use of +// static-inline functions allows the annotations to be read at compile-time, +// while still letting the compiler elide the functions from the final build. +// +// TODO(delesley) -- The exclusive lock here ignores writes as well, but +// allows IGNORE_READS_AND_WRITES to work properly. + +#define ANNOTATE_IGNORE_READS_BEGIN() \ + ABSL_INTERNAL_GLOBAL_SCOPED(AbslInternalAnnotateIgnoreReadsBegin)() + +#define ANNOTATE_IGNORE_READS_END() \ + ABSL_INTERNAL_GLOBAL_SCOPED(AbslInternalAnnotateIgnoreReadsEnd)() + +#else + +#define ANNOTATE_IGNORE_READS_BEGIN() // empty +#define ANNOTATE_IGNORE_READS_END() // empty + +#endif + +// ------------------------------------------------------------------------- +// Define IGNORE_WRITES_BEGIN/_END annotations. + +#if ABSL_INTERNAL_WRITES_ANNOTATIONS_ENABLED == 1 + +// Similar to ANNOTATE_IGNORE_READS_BEGIN, but ignore writes instead. +#define ANNOTATE_IGNORE_WRITES_BEGIN() \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateIgnoreWritesBegin)(__FILE__, __LINE__) + +// Stop ignoring writes. +#define ANNOTATE_IGNORE_WRITES_END() \ + ABSL_INTERNAL_GLOBAL_SCOPED(AnnotateIgnoreWritesEnd)(__FILE__, __LINE__) + +#else + +#define ANNOTATE_IGNORE_WRITES_BEGIN() // empty +#define ANNOTATE_IGNORE_WRITES_END() // empty + +#endif + +// ------------------------------------------------------------------------- +// Define the ANNOTATE_IGNORE_READS_AND_WRITES_* annotations using the more +// primitive annotations defined above. +// +// Instead of doing +// ANNOTATE_IGNORE_READS_BEGIN(); +// ... = x; +// ANNOTATE_IGNORE_READS_END(); +// one can use +// ... = ANNOTATE_UNPROTECTED_READ(x); + +#if defined(ABSL_INTERNAL_READS_WRITES_ANNOTATIONS_ENABLED) + +// Start ignoring all memory accesses (both reads and writes). +#define ANNOTATE_IGNORE_READS_AND_WRITES_BEGIN() \ + do { \ + ANNOTATE_IGNORE_READS_BEGIN(); \ + ANNOTATE_IGNORE_WRITES_BEGIN(); \ + } while (0) + +// Stop ignoring both reads and writes. +#define ANNOTATE_IGNORE_READS_AND_WRITES_END() \ + do { \ + ANNOTATE_IGNORE_WRITES_END(); \ + ANNOTATE_IGNORE_READS_END(); \ + } while (0) + +#ifdef __cplusplus +// ANNOTATE_UNPROTECTED_READ is the preferred way to annotate racey reads. +#define ANNOTATE_UNPROTECTED_READ(x) \ + absl::base_internal::AnnotateUnprotectedRead(x) + +#endif + +#else + +#define ANNOTATE_IGNORE_READS_AND_WRITES_BEGIN() // empty +#define ANNOTATE_IGNORE_READS_AND_WRITES_END() // empty +#define ANNOTATE_UNPROTECTED_READ(x) (x) + +#endif + +// ------------------------------------------------------------------------- +// Address sanitizer annotations + +#ifdef ABSL_HAVE_ADDRESS_SANITIZER +// Describe the current state of a contiguous container such as e.g. +// std::vector or std::string. For more details see +// sanitizer/common_interface_defs.h, which is provided by the compiler. +#include <sanitizer/common_interface_defs.h> + +#define ANNOTATE_CONTIGUOUS_CONTAINER(beg, end, old_mid, new_mid) \ + __sanitizer_annotate_contiguous_container(beg, end, old_mid, new_mid) +#define ADDRESS_SANITIZER_REDZONE(name) \ + struct { \ + char x[8] __attribute__((aligned(8))); \ + } name + +#else + +#define ANNOTATE_CONTIGUOUS_CONTAINER(beg, end, old_mid, new_mid) +#define ADDRESS_SANITIZER_REDZONE(name) static_assert(true, "") + +#endif // ABSL_HAVE_ADDRESS_SANITIZER + +// ------------------------------------------------------------------------- +// Undefine the macros intended only for this file. + +#undef ABSL_INTERNAL_RACE_ANNOTATIONS_ENABLED +#undef ABSL_INTERNAL_MEMORY_ANNOTATIONS_ENABLED +#undef ABSL_INTERNAL_READS_ANNOTATIONS_ENABLED +#undef ABSL_INTERNAL_WRITES_ANNOTATIONS_ENABLED +#undef ABSL_INTERNAL_ANNOTALYSIS_ENABLED +#undef ABSL_INTERNAL_READS_WRITES_ANNOTATIONS_ENABLED +#undef ABSL_INTERNAL_BEGIN_EXTERN_C +#undef ABSL_INTERNAL_END_EXTERN_C +#undef ABSL_INTERNAL_STATIC_INLINE + +#endif // ABSL_BASE_INTERNAL_DYNAMIC_ANNOTATIONS_H_ |