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authorLei Zhang <thestig@chromium.org>2018-07-09 18:58:37 +0000
committerChromium commit bot <commit-bot@chromium.org>2018-07-09 18:58:37 +0000
commit43f6bc80a29fdf326729903e9f323850e9553c69 (patch)
tree76683eacb9e8992853fea064110d1871b0c97947 /third_party/base/debug
parent245c7310a74e1ed81c885b3404a8cedf0c58f4b8 (diff)
downloadpdfium-43f6bc80a29fdf326729903e9f323850e9553c69.tar.xz
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 <dsinclair@chromium.org> Commit-Queue: Lei Zhang <thestig@chromium.org>
Diffstat (limited to 'third_party/base/debug')
-rw-r--r--third_party/base/debug/alias.cc28
-rw-r--r--third_party/base/debug/alias.h32
2 files changed, 60 insertions, 0 deletions
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_