/*
* 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_DYNAMIC_ANNOTATIONS_H_
#define ABSL_BASE_DYNAMIC_ANNOTATIONS_H_
#ifndef DYNAMIC_ANNOTATIONS_ENABLED
# define DYNAMIC_ANNOTATIONS_ENABLED 0
#endif
#if DYNAMIC_ANNOTATIONS_ENABLED != 0
/* -------------------------------------------------------------
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) \
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) \
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) \
AnnotateEnableRaceDetection(__FILE__, __LINE__, enable)
/* -------------------------------------------------------------
Annotations useful for debugging. */
/* Report the current thread name to a race detector. */
#define ANNOTATE_THREAD_NAME(name) \
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) \
AnnotateRWLockCreate(__FILE__, __LINE__, lock)
/* Report that a linker initialized lock has been created at address "lock".
*/
#ifdef THREAD_SANITIZER
#define ANNOTATE_RWLOCK_CREATE_STATIC(lock) \
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) \
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) \
AnnotateRWLockAcquired(__FILE__, __LINE__, lock, is_w)
/* Report that the lock at address "lock" is about to be released. */
#define ANNOTATE_RWLOCK_RELEASED(lock, is_w) \
AnnotateRWLockReleased(__FILE__, __LINE__, lock, is_w)
#else /* DYNAMIC_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 */
#endif /* DYNAMIC_ANNOTATIONS_ENABLED */
/* These annotations are also made available to LLVM's Memory Sanitizer */
#if DYNAMIC_ANNOTATIONS_ENABLED == 1 || defined(MEMORY_SANITIZER)
#define ANNOTATE_MEMORY_IS_INITIALIZED(address, size) \
AnnotateMemoryIsInitialized(__FILE__, __LINE__, address, size)
#define ANNOTATE_MEMORY_IS_UNINITIALIZED(address, size) \
AnnotateMemoryIsUninitialized(__FILE__, __LINE__, address, size)
#else
#define ANNOTATE_MEMORY_IS_INITIALIZED(address, size) /* empty */
#define ANNOTATE_MEMORY_IS_UNINITIALIZED(address, size) /* empty */
#endif /* DYNAMIC_ANNOTATIONS_ENABLED || MEMORY_SANITIZER */
/* TODO(delesley) -- Replace __CLANG_SUPPORT_DYN_ANNOTATION__ with the
appropriate feature ID. */
#if defined(__clang__) && (!defined(SWIG)) \
&& defined(__CLANG_SUPPORT_DYN_ANNOTATION__)
#if DYNAMIC_ANNOTATIONS_ENABLED == 0
#define ANNOTALYSIS_ENABLED
#endif
/* When running in opt-mode, GCC will issue a warning, if these attributes are
compiled. Only include them when compiling using Clang. */
#define ATTRIBUTE_IGNORE_READS_BEGIN \
__attribute((exclusive_lock_function("*")))
#define ATTRIBUTE_IGNORE_READS_END \
__attribute((unlock_function("*")))
#else
#define ATTRIBUTE_IGNORE_READS_BEGIN /* empty */
#define ATTRIBUTE_IGNORE_READS_END /* empty */
#endif /* defined(__clang__) && ... */
#if (DYNAMIC_ANNOTATIONS_ENABLED != 0) || defined(ANNOTALYSIS_ENABLED)
#define ANNOTATIONS_ENABLED
#endif
#if (DYNAMIC_ANNOTATIONS_ENABLED != 0)
/* 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() \
AnnotateIgnoreReadsBegin(__FILE__, __LINE__)
/* Stop ignoring reads. */
#define ANNOTATE_IGNORE_READS_END() \
AnnotateIgnoreReadsEnd(__FILE__, __LINE__)
/* Similar to ANNOTATE_IGNORE_READS_BEGIN, but ignore writes instead. */
#define ANNOTATE_IGNORE_WRITES_BEGIN() \
AnnotateIgnoreWritesBegin(__FILE__, __LINE__)
/* Stop ignoring writes. */
#define ANNOTATE_IGNORE_WRITES_END() \
AnnotateIgnoreWritesEnd(__FILE__, __LINE__)
/* 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. */
#elif defined(ANNOTALYSIS_ENABLED)
#define ANNOTATE_IGNORE_READS_BEGIN() \
StaticAnnotateIgnoreReadsBegin(__FILE__, __LINE__)
#define ANNOTATE_IGNORE_READS_END() \
StaticAnnotateIgnoreReadsEnd(__FILE__, __LINE__)
#define ANNOTATE_IGNORE_WRITES_BEGIN() \
StaticAnnotateIgnoreWritesBegin(__FILE__, __LINE__)
#define ANNOTATE_IGNORE_WRITES_END() \
StaticAnnotateIgnoreWritesEnd(__FILE__, __LINE__)
#else
#define ANNOTATE_IGNORE_READS_BEGIN() /* empty */
#define ANNOTATE_IGNORE_READS_END() /* empty */
#define ANNOTATE_IGNORE_WRITES_BEGIN() /* empty */
#define ANNOTATE_IGNORE_WRITES_END() /* empty */
#endif
/* Implement the ANNOTATE_IGNORE_READS_AND_WRITES_* annotations using the more
primitive annotations defined above. */
#if defined(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)
#else
#define ANNOTATE_IGNORE_READS_AND_WRITES_BEGIN() /* empty */
#define ANNOTATE_IGNORE_READS_AND_WRITES_END() /* empty */
#endif
/* Use the macros above rather than using these functions directly. */
#include <stddef.h>
#ifdef __cplusplus
extern "C" {
#endif
void AnnotateRWLockCreate(const char *file, int line,
const volatile void *lock);
void AnnotateRWLockCreateStatic(const char *file, int line,
const volatile void *lock);
void AnnotateRWLockDestroy(const char *file, int line,
const volatile void *lock);
void AnnotateRWLockAcquired(const char *file, int line,
const volatile void *lock, long is_w); /* NOLINT */
void AnnotateRWLockReleased(const char *file, int line,
const volatile void *lock, long is_w); /* NOLINT */
void AnnotateBenignRace(const char *file, int line,
const volatile void *address,
const char *description);
void AnnotateBenignRaceSized(const char *file, int line,
const volatile void *address,
size_t size,
const char *description);
void AnnotateThreadName(const char *file, int line,
const char *name);
void AnnotateEnableRaceDetection(const char *file, int line, int enable);
void AnnotateMemoryIsInitialized(const char *file, int line,
const volatile void *mem, size_t size);
void AnnotateMemoryIsUninitialized(const char *file, int line,
const volatile void *mem, size_t size);
/* Annotations expand to these functions, when Dynamic Annotations are enabled.
These functions are either implemented as no-op calls, if no Sanitizer is
attached, or provided with externally-linked implementations by a library
like ThreadSanitizer. */
void AnnotateIgnoreReadsBegin(const char *file, int line)
ATTRIBUTE_IGNORE_READS_BEGIN;
void AnnotateIgnoreReadsEnd(const char *file, int line)
ATTRIBUTE_IGNORE_READS_END;
void AnnotateIgnoreWritesBegin(const char *file, int line);
void AnnotateIgnoreWritesEnd(const char *file, int line);
#if defined(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. */
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
static inline void StaticAnnotateIgnoreReadsBegin(const char *file, int line)
ATTRIBUTE_IGNORE_READS_BEGIN { (void)file; (void)line; }
static inline void StaticAnnotateIgnoreReadsEnd(const char *file, int line)
ATTRIBUTE_IGNORE_READS_END { (void)file; (void)line; }
static inline void StaticAnnotateIgnoreWritesBegin(
const char *file, int line) { (void)file; (void)line; }
static inline void StaticAnnotateIgnoreWritesEnd(
const char *file, int line) { (void)file; (void)line; }
#pragma GCC diagnostic pop
#endif
/* Return non-zero value if running under valgrind.
If "valgrind.h" is included into dynamic_annotations.cc,
the regular valgrind mechanism will be used.
See http://valgrind.org/docs/manual/manual-core-adv.html about
RUNNING_ON_VALGRIND and other valgrind "client requests".
The file "valgrind.h" may be obtained by doing
svn co svn://svn.valgrind.org/valgrind/trunk/include
If for some reason you can't use "valgrind.h" or want to fake valgrind,
there are two ways to make this function return non-zero:
- Use environment variable: export RUNNING_ON_VALGRIND=1
- Make your tool intercept the function RunningOnValgrind() and
change its return value.
*/
int RunningOnValgrind(void);
/* ValgrindSlowdown returns:
* 1.0, if (RunningOnValgrind() == 0)
* 50.0, if (RunningOnValgrind() != 0 && getenv("VALGRIND_SLOWDOWN") == NULL)
* atof(getenv("VALGRIND_SLOWDOWN")) otherwise
This function can be used to scale timeout values:
EXAMPLE:
for (;;) {
DoExpensiveBackgroundTask();
SleepForSeconds(5 * ValgrindSlowdown());
}
*/
double ValgrindSlowdown(void);
#ifdef __cplusplus
}
#endif
/* ANNOTATE_UNPROTECTED_READ is the preferred way to annotate racey reads.
Instead of doing
ANNOTATE_IGNORE_READS_BEGIN();
... = x;
ANNOTATE_IGNORE_READS_END();
one can use
... = ANNOTATE_UNPROTECTED_READ(x); */
#if defined(__cplusplus) && defined(ANNOTATIONS_ENABLED)
template <typename T>
inline T ANNOTATE_UNPROTECTED_READ(const volatile T &x) { /* NOLINT */
ANNOTATE_IGNORE_READS_BEGIN();
T res = x;
ANNOTATE_IGNORE_READS_END();
return res;
}
#else
#define ANNOTATE_UNPROTECTED_READ(x) (x)
#endif
#if DYNAMIC_ANNOTATIONS_ENABLED != 0 && defined(__cplusplus)
/* Apply ANNOTATE_BENIGN_RACE_SIZED to a static variable. */
#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 /* DYNAMIC_ANNOTATIONS_ENABLED == 0 */
#define ANNOTATE_BENIGN_RACE_STATIC(static_var, description) /* empty */
#endif /* DYNAMIC_ANNOTATIONS_ENABLED */
#ifdef 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)
#endif // ADDRESS_SANITIZER
/* Undefine the macros intended only in this file. */
#undef ANNOTALYSIS_ENABLED
#undef ANNOTATIONS_ENABLED
#undef ATTRIBUTE_IGNORE_READS_BEGIN
#undef ATTRIBUTE_IGNORE_READS_END
#endif /* ABSL_BASE_DYNAMIC_ANNOTATIONS_H_ */
