michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef BASE_COMPILER_SPECIFIC_H_
michael@0: #define BASE_COMPILER_SPECIFIC_H_
michael@0: 
michael@0: #include "build/build_config.h"
michael@0: 
michael@0: #if defined(COMPILER_MSVC)
michael@0: 
michael@0: // Macros for suppressing and disabling warnings on MSVC.
michael@0: //
michael@0: // Warning numbers are enumerated at:
michael@0: // http://msdn.microsoft.com/en-us/library/8x5x43k7(VS.80).aspx
michael@0: //
michael@0: // The warning pragma:
michael@0: // http://msdn.microsoft.com/en-us/library/2c8f766e(VS.80).aspx
michael@0: //
michael@0: // Using __pragma instead of #pragma inside macros:
michael@0: // http://msdn.microsoft.com/en-us/library/d9x1s805.aspx
michael@0: 
michael@0: // MSVC_SUPPRESS_WARNING disables warning |n| for the remainder of the line and
michael@0: // for the next line of the source file.
michael@0: #define MSVC_SUPPRESS_WARNING(n) __pragma(warning(suppress:n))
michael@0: 
michael@0: // MSVC_PUSH_DISABLE_WARNING pushes |n| onto a stack of warnings to be disabled.
michael@0: // The warning remains disabled until popped by MSVC_POP_WARNING.
michael@0: #define MSVC_PUSH_DISABLE_WARNING(n) __pragma(warning(push)) \
michael@0:                                      __pragma(warning(disable:n))
michael@0: 
michael@0: // MSVC_PUSH_WARNING_LEVEL pushes |n| as the global warning level.  The level
michael@0: // remains in effect until popped by MSVC_POP_WARNING().  Use 0 to disable all
michael@0: // warnings.
michael@0: #define MSVC_PUSH_WARNING_LEVEL(n) __pragma(warning(push, n))
michael@0: 
michael@0: // Pop effects of innermost MSVC_PUSH_* macro.
michael@0: #define MSVC_POP_WARNING() __pragma(warning(pop))
michael@0: 
michael@0: #define MSVC_DISABLE_OPTIMIZE() __pragma(optimize("", off))
michael@0: #define MSVC_ENABLE_OPTIMIZE() __pragma(optimize("", on))
michael@0: 
michael@0: // Allows exporting a class that inherits from a non-exported base class.
michael@0: // This uses suppress instead of push/pop because the delimiter after the
michael@0: // declaration (either "," or "{") has to be placed before the pop macro.
michael@0: //
michael@0: // Example usage:
michael@0: // class EXPORT_API Foo : NON_EXPORTED_BASE(public Bar) {
michael@0: //
michael@0: // MSVC Compiler warning C4275:
michael@0: // non dll-interface class 'Bar' used as base for dll-interface class 'Foo'.
michael@0: // Note that this is intended to be used only when no access to the base class'
michael@0: // static data is done through derived classes or inline methods. For more info,
michael@0: // see http://msdn.microsoft.com/en-us/library/3tdb471s(VS.80).aspx
michael@0: #define NON_EXPORTED_BASE(code) MSVC_SUPPRESS_WARNING(4275) \
michael@0:                                 code
michael@0: 
michael@0: #else  // Not MSVC
michael@0: 
michael@0: #define MSVC_SUPPRESS_WARNING(n)
michael@0: #define MSVC_PUSH_DISABLE_WARNING(n)
michael@0: #define MSVC_PUSH_WARNING_LEVEL(n)
michael@0: #define MSVC_POP_WARNING()
michael@0: #define MSVC_DISABLE_OPTIMIZE()
michael@0: #define MSVC_ENABLE_OPTIMIZE()
michael@0: #define NON_EXPORTED_BASE(code) code
michael@0: 
michael@0: #endif  // COMPILER_MSVC
michael@0: 
michael@0: 
michael@0: // Annotate a variable indicating it's ok if the variable is not used.
michael@0: // (Typically used to silence a compiler warning when the assignment
michael@0: // is important for some other reason.)
michael@0: // Use like:
michael@0: //   int x ALLOW_UNUSED = ...;
michael@0: #if defined(COMPILER_GCC)
michael@0: #define ALLOW_UNUSED __attribute__((unused))
michael@0: #else
michael@0: #define ALLOW_UNUSED
michael@0: #endif
michael@0: 
michael@0: // Annotate a function indicating it should not be inlined.
michael@0: // Use like:
michael@0: //   NOINLINE void DoStuff() { ... }
michael@0: #if defined(COMPILER_GCC)
michael@0: #define NOINLINE __attribute__((noinline))
michael@0: #elif defined(COMPILER_MSVC)
michael@0: #define NOINLINE __declspec(noinline)
michael@0: #else
michael@0: #define NOINLINE
michael@0: #endif
michael@0: 
michael@0: // Specify memory alignment for structs, classes, etc.
michael@0: // Use like:
michael@0: //   class ALIGNAS(16) MyClass { ... }
michael@0: //   ALIGNAS(16) int array[4];
michael@0: #if defined(COMPILER_MSVC)
michael@0: #define ALIGNAS(byte_alignment) __declspec(align(byte_alignment))
michael@0: #elif defined(COMPILER_GCC)
michael@0: #define ALIGNAS(byte_alignment) __attribute__((aligned(byte_alignment)))
michael@0: #endif
michael@0: 
michael@0: // Return the byte alignment of the given type (available at compile time).  Use
michael@0: // sizeof(type) prior to checking __alignof to workaround Visual C++ bug:
michael@0: // http://goo.gl/isH0C
michael@0: // Use like:
michael@0: //   ALIGNOF(int32)  // this would be 4
michael@0: #if defined(COMPILER_MSVC)
michael@0: #define ALIGNOF(type) (sizeof(type) - sizeof(type) + __alignof(type))
michael@0: #elif defined(COMPILER_GCC)
michael@0: #define ALIGNOF(type) __alignof__(type)
michael@0: #endif
michael@0: 
michael@0: // Annotate a virtual method indicating it must be overriding a virtual
michael@0: // method in the parent class.
michael@0: // Use like:
michael@0: //   virtual void foo() OVERRIDE;
michael@0: #if defined(COMPILER_MSVC)
michael@0: #define OVERRIDE override
michael@0: #elif defined(__clang__)
michael@0: #define OVERRIDE override
michael@0: #else
michael@0: #define OVERRIDE
michael@0: #endif
michael@0: 
michael@0: // Annotate a virtual method indicating that subclasses must not override it,
michael@0: // or annotate a class to indicate that it cannot be subclassed.
michael@0: // Use like:
michael@0: //   virtual void foo() FINAL;
michael@0: //   class B FINAL : public A {};
michael@0: #if defined(COMPILER_MSVC)
michael@0: // TODO(jered): Change this to "final" when chromium no longer uses MSVC 2010.
michael@0: #define FINAL sealed
michael@0: #elif defined(__clang__)
michael@0: #define FINAL final
michael@0: #else
michael@0: #define FINAL
michael@0: #endif
michael@0: 
michael@0: // Annotate a function indicating the caller must examine the return value.
michael@0: // Use like:
michael@0: //   int foo() WARN_UNUSED_RESULT;
michael@0: // To explicitly ignore a result, see |ignore_result()| in <base/basictypes.h>.
michael@0: #if defined(COMPILER_GCC)
michael@0: #define WARN_UNUSED_RESULT __attribute__((warn_unused_result))
michael@0: #else
michael@0: #define WARN_UNUSED_RESULT
michael@0: #endif
michael@0: 
michael@0: // Tell the compiler a function is using a printf-style format string.
michael@0: // |format_param| is the one-based index of the format string parameter;
michael@0: // |dots_param| is the one-based index of the "..." parameter.
michael@0: // For v*printf functions (which take a va_list), pass 0 for dots_param.
michael@0: // (This is undocumented but matches what the system C headers do.)
michael@0: #if defined(COMPILER_GCC)
michael@0: #define PRINTF_FORMAT(format_param, dots_param) \
michael@0:     __attribute__((format(printf, format_param, dots_param)))
michael@0: #else
michael@0: #define PRINTF_FORMAT(format_param, dots_param)
michael@0: #endif
michael@0: 
michael@0: // WPRINTF_FORMAT is the same, but for wide format strings.
michael@0: // This doesn't appear to yet be implemented in any compiler.
michael@0: // See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38308 .
michael@0: #define WPRINTF_FORMAT(format_param, dots_param)
michael@0: // If available, it would look like:
michael@0: //   __attribute__((format(wprintf, format_param, dots_param)))
michael@0: 
michael@0: 
michael@0: // MemorySanitizer annotations.
michael@0: #ifdef MEMORY_SANITIZER
michael@0: extern "C" {
michael@0: void __msan_unpoison(const void *p, unsigned long s);
michael@0: }  // extern "C"
michael@0: 
michael@0: // Mark a memory region fully initialized.
michael@0: // Use this to annotate code that deliberately reads uninitialized data, for
michael@0: // example a GC scavenging root set pointers from the stack.
michael@0: #define MSAN_UNPOISON(p, s)  __msan_unpoison(p, s)
michael@0: #else  // MEMORY_SANITIZER
michael@0: #define MSAN_UNPOISON(p, s)
michael@0: #endif  // MEMORY_SANITIZER
michael@0: 
michael@0: #endif  // BASE_COMPILER_SPECIFIC_H_