// 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)
// 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 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
// The C++ standard requires that static const members have an out-of-class
// definition (in a single compilation unit), but MSVC chokes on this (when
// language extensions, which are required, are enabled). (You're only likely to
// notice the need for a definition if you take the address of the member or,
// more commonly, pass it to a function that takes it as a reference argument --
// probably an STL function.) This macro makes MSVC do the right thing. See
// http://msdn.microsoft.com/en-us/library/34h23df8(v=vs.100).aspx for more
// information. Use like:
//
// In .h file:
// struct Foo {
// static const int kBar = 5;
// };
//
// In .cc file:
// STATIC_CONST_MEMBER_DEFINITION const int Foo::kBar;
#if defined(COMPILER_MSVC)
#define STATIC_CONST_MEMBER_DEFINITION __declspec(selectany)
#else
#define STATIC_CONST_MEMBER_DEFINITION
#endif
// 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))
#else
#define ALLOW_UNUSED
#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
// 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
// sizeof(type) prior to checking __alignof to workaround Visual C++ bug:
// http://goo.gl/isH0C
// Use like:
// ALIGNOF(int32) // this would be 4
#if defined(COMPILER_MSVC)
#define ALIGNOF(type) (sizeof(type) - sizeof(type) + __alignof(type))
#elif defined(COMPILER_GCC)
#define ALIGNOF(type) __alignof__(type)
#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
#elif defined(COMPILER_GCC) && __cplusplus >= 201103 && \
(__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >= 40700
// GCC 4.7 supports explicit virtual overrides when C++11 support is enabled.
#define OVERRIDE override
#else
#define OVERRIDE
#endif
// Annotate a virtual method indicating that subclasses must not override it,
// or annotate a class to indicate that it cannot be subclassed.
// Use like:
// virtual void foo() FINAL;
// class B FINAL : public A {};
#if defined(__clang__)
#define FINAL final
#elif defined(COMPILER_MSVC)
// TODO(thakis): Remove if !defined() once Blink is updated too.
#if !defined(FINAL)
#define FINAL final
#endif
#elif defined(COMPILER_GCC) && __cplusplus >= 201103 && \
(__GNUC__ * 10000 + __GNUC_MINOR__ * 100) >= 40700
// GCC 4.7 supports explicit virtual overrides when C++11 support is enabled.
#define FINAL final
#else
#define FINAL
#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)))
// 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, s) __msan_unpoison(p, s)
#else // MEMORY_SANITIZER
#define MSAN_UNPOISON(p, s)
#endif // MEMORY_SANITIZER
// 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)
#endif // BASE_COMPILER_SPECIFIC_H_