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Diffstat (limited to 'third_party/base/compiler_specific.h')
| -rw-r--r-- | third_party/base/compiler_specific.h | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/third_party/base/compiler_specific.h b/third_party/base/compiler_specific.h new file mode 100644 index 0000000000..832b95bf5f --- /dev/null +++ b/third_party/base/compiler_specific.h @@ -0,0 +1,233 @@ +// Copyright (c) 2012 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef BASE_COMPILER_SPECIFIC_H_ +#define BASE_COMPILER_SPECIFIC_H_ + +#include "build/build_config.h" + +#if defined(COMPILER_MSVC) + +// For _Printf_format_string_. +#include <sal.h> + +// Macros for suppressing and disabling warnings on MSVC. +// +// Warning numbers are enumerated at: +// http://msdn.microsoft.com/en-us/library/8x5x43k7(VS.80).aspx +// +// The warning pragma: +// http://msdn.microsoft.com/en-us/library/2c8f766e(VS.80).aspx +// +// Using __pragma instead of #pragma inside macros: +// http://msdn.microsoft.com/en-us/library/d9x1s805.aspx + +// MSVC_SUPPRESS_WARNING disables warning |n| for the remainder of the line and +// for the next line of the source file. +#define MSVC_SUPPRESS_WARNING(n) __pragma(warning(suppress : n)) + +// MSVC_PUSH_DISABLE_WARNING pushes |n| onto a stack of warnings to be disabled. +// The warning remains disabled until popped by MSVC_POP_WARNING. +#define MSVC_PUSH_DISABLE_WARNING(n) \ + __pragma(warning(push)) __pragma(warning(disable : n)) + +// MSVC_PUSH_WARNING_LEVEL pushes |n| as the global warning level. The level +// remains in effect until popped by MSVC_POP_WARNING(). Use 0 to disable all +// warnings. +#define MSVC_PUSH_WARNING_LEVEL(n) __pragma(warning(push, n)) + +// Pop effects of innermost MSVC_PUSH_* macro. +#define MSVC_POP_WARNING() __pragma(warning(pop)) + +#define MSVC_DISABLE_OPTIMIZE() __pragma(optimize("", off)) +#define MSVC_ENABLE_OPTIMIZE() __pragma(optimize("", on)) + +// Allows exporting a class that inherits from a non-exported base class. +// This uses suppress instead of push/pop because the delimiter after the +// declaration (either "," or "{") has to be placed before the pop macro. +// +// Example usage: +// class EXPORT_API Foo : NON_EXPORTED_BASE(public Bar) { +// +// MSVC Compiler warning C4275: +// non dll-interface class 'Bar' used as base for dll-interface class 'Foo'. +// Note that this is intended to be used only when no access to the base class' +// static data is done through derived classes or inline methods. For more info, +// see http://msdn.microsoft.com/en-us/library/3tdb471s(VS.80).aspx +#define NON_EXPORTED_BASE(code) \ + MSVC_SUPPRESS_WARNING(4275) \ + code + +#else // Not MSVC + +#define _Printf_format_string_ +#define MSVC_SUPPRESS_WARNING(n) +#define MSVC_PUSH_DISABLE_WARNING(n) +#define MSVC_PUSH_WARNING_LEVEL(n) +#define MSVC_POP_WARNING() +#define MSVC_DISABLE_OPTIMIZE() +#define MSVC_ENABLE_OPTIMIZE() +#define NON_EXPORTED_BASE(code) code + +#endif // COMPILER_MSVC + +// Annotate a variable indicating it's ok if the variable is not used. +// (Typically used to silence a compiler warning when the assignment +// is important for some other reason.) +// Use like: +// int x = ...; +// ALLOW_UNUSED_LOCAL(x); +#define ALLOW_UNUSED_LOCAL(x) false ? (void)x : (void)0 + +// Annotate a typedef or function indicating it's ok if it's not used. +// Use like: +// typedef Foo Bar ALLOW_UNUSED_TYPE; +#if defined(COMPILER_GCC) || defined(__clang__) +#define ALLOW_UNUSED_TYPE __attribute__((unused)) +#else +#define ALLOW_UNUSED_TYPE +#endif + +// Annotate a function indicating it should not be inlined. +// Use like: +// NOINLINE void DoStuff() { ... } +#if defined(COMPILER_GCC) +#define NOINLINE __attribute__((noinline)) +#elif defined(COMPILER_MSVC) +#define NOINLINE __declspec(noinline) +#else +#define NOINLINE +#endif + +#if COMPILER_GCC && defined(NDEBUG) +#define ALWAYS_INLINE inline __attribute__((__always_inline__)) +#elif COMPILER_MSVC && defined(NDEBUG) +#define ALWAYS_INLINE __forceinline +#else +#define ALWAYS_INLINE inline +#endif + +// Specify memory alignment for structs, classes, etc. +// Use like: +// class ALIGNAS(16) MyClass { ... } +// ALIGNAS(16) int array[4]; +#if defined(COMPILER_MSVC) +#define ALIGNAS(byte_alignment) __declspec(align(byte_alignment)) +#elif defined(COMPILER_GCC) +#define ALIGNAS(byte_alignment) __attribute__((aligned(byte_alignment))) +#endif + +// Return the byte alignment of the given type (available at compile time). +// Use like: +// ALIGNOF(int32_t) // this would be 4 +#if defined(COMPILER_MSVC) +#define ALIGNOF(type) __alignof(type) +#elif defined(COMPILER_GCC) +#define ALIGNOF(type) __alignof__(type) +#endif + +// Annotate a function indicating the caller must examine the return value. +// Use like: +// int foo() WARN_UNUSED_RESULT; +// To explicitly ignore a result, see |ignore_result()| in base/macros.h. +#undef WARN_UNUSED_RESULT +#if defined(COMPILER_GCC) || defined(__clang__) +#define WARN_UNUSED_RESULT __attribute__((warn_unused_result)) +#else +#define WARN_UNUSED_RESULT +#endif + +// Tell the compiler a function is using a printf-style format string. +// |format_param| is the one-based index of the format string parameter; +// |dots_param| is the one-based index of the "..." parameter. +// For v*printf functions (which take a va_list), pass 0 for dots_param. +// (This is undocumented but matches what the system C headers do.) +#if defined(COMPILER_GCC) +#define PRINTF_FORMAT(format_param, dots_param) \ + __attribute__((format(printf, format_param, dots_param))) +#else +#define PRINTF_FORMAT(format_param, dots_param) +#endif + +// WPRINTF_FORMAT is the same, but for wide format strings. +// This doesn't appear to yet be implemented in any compiler. +// See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38308 . +#define WPRINTF_FORMAT(format_param, dots_param) +// If available, it would look like: +// __attribute__((format(wprintf, format_param, dots_param))) + +// Sanitizers annotations. +#if defined(__has_attribute) +#if __has_attribute(no_sanitize) +#define NO_SANITIZE(what) __attribute__((no_sanitize(what))) +#endif +#endif +#if !defined(NO_SANITIZE) +#define NO_SANITIZE(what) +#endif + +// MemorySanitizer annotations. +#if defined(MEMORY_SANITIZER) && !defined(OS_NACL) +#include <sanitizer/msan_interface.h> + +// Mark a memory region fully initialized. +// Use this to annotate code that deliberately reads uninitialized data, for +// example a GC scavenging root set pointers from the stack. +#define MSAN_UNPOISON(p, size) __msan_unpoison(p, size) + +// Check a memory region for initializedness, as if it was being used here. +// If any bits are uninitialized, crash with an MSan report. +// Use this to sanitize data which MSan won't be able to track, e.g. before +// passing data to another process via shared memory. +#define MSAN_CHECK_MEM_IS_INITIALIZED(p, size) \ + __msan_check_mem_is_initialized(p, size) +#else // MEMORY_SANITIZER +#define MSAN_UNPOISON(p, size) +#define MSAN_CHECK_MEM_IS_INITIALIZED(p, size) +#endif // MEMORY_SANITIZER + +// DISABLE_CFI_PERF -- Disable Control Flow Integrity for perf reasons. +#if !defined(DISABLE_CFI_PERF) +#if defined(__clang__) && defined(OFFICIAL_BUILD) +#define DISABLE_CFI_PERF __attribute__((no_sanitize("cfi"))) +#else +#define DISABLE_CFI_PERF +#endif +#endif + +// Macro useful for writing cross-platform function pointers. +#if !defined(CDECL) +#if defined(OS_WIN) +#define CDECL __cdecl +#else // defined(OS_WIN) +#define CDECL +#endif // defined(OS_WIN) +#endif // !defined(CDECL) + +// Macro for hinting that an expression is likely to be false. +#if !defined(UNLIKELY) +#if defined(COMPILER_GCC) +#define UNLIKELY(x) __builtin_expect(!!(x), 0) +#else +#define UNLIKELY(x) (x) +#endif // defined(COMPILER_GCC) +#endif // !defined(UNLIKELY) + +#if !defined(LIKELY) +#if defined(COMPILER_GCC) +#define LIKELY(x) __builtin_expect(!!(x), 1) +#else +#define LIKELY(x) (x) +#endif // defined(COMPILER_GCC) +#endif // !defined(LIKELY) + +// Compiler feature-detection. +// clang.llvm.org/docs/LanguageExtensions.html#has-feature-and-has-extension +#if defined(__has_feature) +#define HAS_FEATURE(FEATURE) __has_feature(FEATURE) +#else +#define HAS_FEATURE(FEATURE) 0 +#endif + +#endif // BASE_COMPILER_SPECIFIC_H_ |