Add run-time CHECK to smoke-test allocator overrides

As part of the refactoring work on the allocator, it emerged that it
would be nice to have a test that ensures that we don't accidentally
break things along the way and not detected that.
This CL adds a runtime CHECK() that verifies that:
 - On Windows (non-component build) the shim layer has been
   initialized. Concretely this checks that chrome called the shimmed
   _heap_init() method and not the one from libcmt.
 - On Linux desktop, the malloc symbols are being overridden by tcmalloc
   (only when USE_TCMALLOC is defined).

The rationale of this test is: if _heap_init was shimmed there are
very good chances that malloc (& friends) were shimmed as well.
Likewise on Linux for mallopt() <-> malloc().

BUG=564618

Review URL: https://codereview.chromium.org/1577883002

Cr-Commit-Position: refs/heads/master@{#369007}

3 files changed, 63 insertions, 0 deletions

diff --git a/base/allocator/allocator_check.cc b/base/allocator/allocator_check.cc
new file mode 100644
index 0000000..4220fb7
--- /dev/null
+++ b/base/allocator/allocator_check.cc
@@ -0,0 +1,38 @@
+// 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.
+
+#include "base/allocator/allocator_check.h"
+
+#include "build/build_config.h"
+
+#if defined(OS_LINUX)
+#include <malloc.h>
+#endif
+
+namespace base {
+namespace allocator {
+
+// Defined in allocator_shim_win.cc .
+// TODO(primiano): replace with an include once base can depend on allocator.
+#if defined(OS_WIN) && defined(ALLOCATOR_SHIM)
+extern bool g_is_win_shim_layer_initialized;
+#endif
+
+bool IsAllocatorInitialized() {
+#if defined(OS_WIN) && defined(ALLOCATOR_SHIM)
+  // Set by allocator_shim_win.cc when the shimmed _heap_init() is called.
+  return g_is_win_shim_layer_initialized;
+#elif defined(OS_LINUX) && defined(USE_TCMALLOC)
+// From third_party/tcmalloc/chromium/src/gperftools/tcmalloc.h.
+// TODO(primiano): replace with an include once base can depend on allocator.
+#define TC_MALLOPT_IS_OVERRIDDEN_BY_TCMALLOC 0xbeef42
+  return (mallopt(TC_MALLOPT_IS_OVERRIDDEN_BY_TCMALLOC, 0) ==
+          TC_MALLOPT_IS_OVERRIDDEN_BY_TCMALLOC);
+#else
+  return true;
+#endif
+}
+
+}  // namespace allocator
+}  // namespace base
diff --git a/base/allocator/allocator_check.h b/base/allocator/allocator_check.h
new file mode 100644
index 0000000..c3aa2cb
--- /dev/null
+++ b/base/allocator/allocator_check.h
@@ -0,0 +1,18 @@
+// Copyright 2015 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_ALLOCATOR_ALLOCATOR_ALLOCATOR_CHECK_H_
+#define BASE_ALLOCATOR_ALLOCATOR_ALLOCATOR_CHECK_H_
+
+#include "base/base_export.h"
+
+namespace base {
+namespace allocator {
+
+BASE_EXPORT bool IsAllocatorInitialized();
+
+}  // namespace allocator
+}  // namespace base
+
+#endif  // BASE_ALLOCATOR_ALLOCATOR_ALLOCATOR_CHECK_H_
diff --git a/base/allocator/allocator_shim_win.cc b/base/allocator/allocator_shim_win.cc
index 2c5a40f..b65544f5 100644
--- a/base/allocator/allocator_shim_win.cc
+++ b/base/allocator/allocator_shim_win.cc
@@ -26,6 +26,12 @@ extern "C" {
 void* _crtheap = reinterpret_cast<void*>(1);
 }
 
+namespace base {
+namespace allocator {
+bool g_is_win_shim_layer_initialized = false;
+}  // namespace allocator
+}  // namespace base
+
 namespace {
 
 const size_t kWindowsPageSize = 4096;
@@ -211,6 +217,7 @@ intptr_t _get_heap_handle() {
 
 // heapinit.c
 int _heap_init() {
+  base::allocator::g_is_win_shim_layer_initialized = true;
   return win_heap_init() ? 1 : 0;
 }