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Diffstat (limited to 'base/compiler_specific.h')
-rw-r--r-- | base/compiler_specific.h | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/base/compiler_specific.h b/base/compiler_specific.h new file mode 100644 index 000000000000..0a6e05a6c679 --- /dev/null +++ b/base/compiler_specific.h @@ -0,0 +1,140 @@ +// Copyright (c) 2011 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_ +#pragma once + +#include "build/build_config.h" + +#if defined(COMPILER_MSVC) + +// 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 |this| to be passed as an argument in constructor initializer lists. +// This uses push/pop instead of the seemingly simpler suppress feature to avoid +// having the warning be disabled for more than just |code|. +// +// Example usage: +// Foo::Foo() : x(NULL), ALLOW_THIS_IN_INITIALIZER_LIST(y(this)), z(3) {} +// +// Compiler warning C4355: 'this': used in base member initializer list: +// http://msdn.microsoft.com/en-us/library/3c594ae3(VS.80).aspx +#define ALLOW_THIS_IN_INITIALIZER_LIST(code) MSVC_PUSH_DISABLE_WARNING(4355) \ + code \ + MSVC_POP_WARNING() + +// 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 +// can be gained through the derived class. 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 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 ALLOW_THIS_IN_INITIALIZER_LIST(code) code +#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 = ...; +#if defined(COMPILER_GCC) +#define ALLOW_UNUSED __attribute__((unused)) +#define NOINLINE __attribute__((noinline)) +#else +#define ALLOW_UNUSED +#define NOINLINE +#endif + +// Annotate a virtual method indicating it must be overriding a virtual +// method in the parent class. +// Use like: +// virtual void foo() OVERRIDE; +#if defined(COMPILER_MSVC) +#define OVERRIDE override +#elif defined(__clang__) +#define OVERRIDE override +#else +#define OVERRIDE +#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/basictypes.h>. +#if defined(COMPILER_GCC) +#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))) + +#endif // BASE_COMPILER_SPECIFIC_H_ |