From 43f6bc80a29fdf326729903e9f323850e9553c69 Mon Sep 17 00:00:00 2001 From: Lei Zhang Date: Mon, 9 Jul 2018 18:58:37 +0000 Subject: Prevent FX_OutOfMemoryTerminate() from being folded by the linker. Copy base::debug::Alias() from Chromium. Use it to prevent ICF from combining FX_OutOfMemoryTerminate() with similar functions. BUG=chromium:860850 Change-Id: Ifccb05c0218f86e44b9bb235847e01383ec36b3f Reviewed-on: https://pdfium-review.googlesource.com/37290 Reviewed-by: dsinclair Commit-Queue: Lei Zhang --- third_party/BUILD.gn | 2 ++ third_party/base/debug/alias.cc | 28 ++++++++++++++++++++++++++++ third_party/base/debug/alias.h | 32 ++++++++++++++++++++++++++++++++ 3 files changed, 62 insertions(+) create mode 100644 third_party/base/debug/alias.cc create mode 100644 third_party/base/debug/alias.h (limited to 'third_party') diff --git a/third_party/BUILD.gn b/third_party/BUILD.gn index 8b212e1622..847229273e 100644 --- a/third_party/BUILD.gn +++ b/third_party/BUILD.gn @@ -554,6 +554,8 @@ jumbo_source_set("pdfium_base") { "base/base_export.h", "base/bits.h", "base/compiler_specific.h", + "base/debug/alias.cc", + "base/debug/alias.h", "base/logging.h", "base/macros.h", "base/numerics/safe_conversions.h", diff --git a/third_party/base/debug/alias.cc b/third_party/base/debug/alias.cc new file mode 100644 index 0000000000..3ab554fe48 --- /dev/null +++ b/third_party/base/debug/alias.cc @@ -0,0 +1,28 @@ +// 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. + +#include "third_party/base/debug/alias.h" + +#include "build/build_config.h" + +namespace base { +namespace debug { + +#if defined(COMPILER_MSVC) +#pragma optimize("", off) +#elif defined(__clang__) +#pragma clang optimize off +#endif + +void Alias(const void* var) { +} + +#if defined(COMPILER_MSVC) +#pragma optimize("", on) +#elif defined(__clang__) +#pragma clang optimize on +#endif + +} // namespace debug +} // namespace base diff --git a/third_party/base/debug/alias.h b/third_party/base/debug/alias.h new file mode 100644 index 0000000000..4d02e7af74 --- /dev/null +++ b/third_party/base/debug/alias.h @@ -0,0 +1,32 @@ +// 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_DEBUG_ALIAS_H_ +#define BASE_DEBUG_ALIAS_H_ + +namespace base { +namespace debug { + +// Make the optimizer think that var is aliased. This is to prevent it from +// optimizing out local variables that would not otherwise be live at the point +// of a potential crash. +// base::debug::Alias should only be used for local variables, not globals, +// object members, or function return values - these must be copied to locals if +// you want to ensure they are recorded in crash dumps. +// Note that if the local variable is a pointer then its value will be retained +// but the memory that it points to will probably not be saved in the crash +// dump - by default only stack memory is saved. Therefore the aliasing +// technique is usually only worthwhile with non-pointer variables. If you have +// a pointer to an object and you want to retain the object's state you need to +// copy the object or its fields to local variables. Example usage: +// int last_error = err_; +// base::debug::Alias(&last_error); +// DEBUG_ALIAS_FOR_CSTR(name_copy, p->name, 16); +// CHECK(false); +void Alias(const void* var); + +} // namespace debug +} // namespace base + +#endif // BASE_DEBUG_ALIAS_H_ -- cgit v1.2.3