Index: content/browser/mac/closure_blocks_leopard_compat.h |
=================================================================== |
--- content/browser/mac/closure_blocks_leopard_compat.h (revision 124212) |
+++ content/browser/mac/closure_blocks_leopard_compat.h (working copy) |
@@ -1,104 +0,0 @@ |
-// 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 CONTENT_BROWSER_MAC_CLOSURE_BLOCKS_LEOPARD_COMPAT_H_ |
-#define CONTENT_BROWSER_MAC_CLOSURE_BLOCKS_LEOPARD_COMPAT_H_ |
-#pragma once |
- |
-// libclosure (blocks) compatibility for Mac OS X 10.5 (Leopard) |
-// |
-// Background material: |
-// http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Blocks |
-// http://opensource.apple.com/source/libclosure/libclosure-38/ |
-// |
-// Leopard doesn't support blocks. Chrome supports Leopard. Chrome needs to use |
-// blocks. |
-// |
-// In any file where you use blocks (any time you type ^{...}), you must |
-// #include this file to ensure that the runtime symbols referenced by code |
-// emitted by the compiler are marked for weak-import. This means that if |
-// these symbols are not present at runtime, the program will still load, but |
-// their values will be NULL. |
-// |
-// In any target (in the GYP sense) where you use blocks, you must also depend |
-// on the closure_blocks_leopard_compat target to ensure that these symbols |
-// will be available at link time, even when the 10.5 SDK is in use. This |
-// allows the continued use of the 10.5 SDK, which does not contain these |
-// symbols. |
-// |
-// This does not relieve you of the responsibility to not use blocks on |
-// Leopard. Because runtime support for Blocks still isn't present on that |
-// operating system, the weak-imported symbols will have value 0 and attempts |
-// to do anything meaningful with them will fail or crash. You must take care |
-// not to enter any codepath that uses blocks on Leopard. The base::mac::IsOS* |
-// family may be helpful. |
-// |
-// Although this scheme allows the use of the 10.5 SDK and 10.5 runtime in an |
-// application that uses blocks, it is still necessary to use a compiler that |
-// supports blocks. GCC 4.2 as shipped with Xcode 3.2 for Mac OS X 10.6 |
-// qualifies, as do sufficiently recent versions of clang. GCC 4.2 as shipped |
-// with Xcode 3.1 for Mac OS X 10.5 does not qualify. |
- |
-// _NSConcreteGlobalBlock and _NSConcreteStackBlock are private implementation |
-// details of libclosure defined in libclosure/libclosure-38/Block_private.h, |
-// but they're exposed from libSystem as public symbols, and the block-enabled |
-// compiler will emit code that references these symbols. Because the symbols |
-// aren't present in 10.5's libSystem, they must be declared as weak imports |
-// in any file that uses blocks. Any block-using file must #include this |
-// header to guarantee that the symbols will show up in linked output as weak |
-// imports when compiling for a 10.5 deployment target. Because the symbols |
-// are always present in 10.6 and higher, they do not need to be a weak |
-// imports when the deployment target is at least 10.6. |
-// |
-// Both GCC and clang emit references to these symbols, providing implicit |
-// declarations as needed, but respecting any user declaration when present. |
-// See gcc-5666.3/gcc/c-parser.c build_block_struct_initlist, |
-// gcc-5666.3/gcc/cp/parser.c build_block_struct_initlist, and |
-// clang-2.9/lib/CodeGen/CodeGenModule.cpp |
-// CodeGenModule::getNSConcreteGlobalBlock() and |
-// CodeGenModule::getNSConcreteStackBlock(). |
- |
-#include <AvailabilityMacros.h> |
- |
-#if defined(MAC_OS_X_VERSION_10_6) && \ |
- MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_6 // SDK >= 10.6 |
-// Get the system's own declarations of these things if using an SDK where |
-// they are present. |
-#include <Block.h> |
-#endif // SDK >= 10.6 |
- |
-extern "C" { |
- |
-#if MAC_OS_X_VERSION_MIN_REQUIRED <= MAC_OS_X_VERSION_10_5 // DT <= 10.5 |
-#define MAYBE_WEAK_IMPORT __attribute__((weak_import)) |
-#else // DT > 10.5 |
-#define MAYBE_WEAK_IMPORT |
-#endif // DT <= 10.5 |
- |
-MAYBE_WEAK_IMPORT extern void* _Block_copy(const void*); |
-MAYBE_WEAK_IMPORT extern void _Block_release(const void*); |
-MAYBE_WEAK_IMPORT extern void _Block_object_assign(void*, |
- const void*, |
- const int); |
-MAYBE_WEAK_IMPORT extern void _Block_object_dispose(const void*, const int); |
- |
-MAYBE_WEAK_IMPORT extern void* _NSConcreteGlobalBlock[32]; |
-MAYBE_WEAK_IMPORT extern void* _NSConcreteStackBlock[32]; |
- |
-#undef MAYBE_WEAK_IMPORT |
- |
-} // extern "C" |
- |
-// Macros from <Block.h>, in case <Block.h> is not present. |
- |
-#ifndef Block_copy |
-#define Block_copy(...) \ |
- ((__typeof(__VA_ARGS__))_Block_copy((const void *)(__VA_ARGS__))) |
-#endif |
- |
-#ifndef Block_release |
-#define Block_release(...) _Block_release((const void *)(__VA_ARGS__)) |
-#endif |
- |
-#endif // CONTENT_BROWSER_MAC_CLOSURE_BLOCKS_LEOPARD_COMPAT_H_ |