Updated MallocHooks to collect stack traces when memory is allocated.

runtime/vm/os_linux.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_OS_LINUX)
 
 #include "vm/os.h"
 
 #include <errno.h>         // NOLINT
@@ skipping 269 matching lines @@
 
 
 // TODO(regis, iposva): When this function is no longer called from the
 // CodeImmutability test in object_test.cc, it will be called only from the
 // simulator, which means that only the Intel implementation is needed.
 void OS::DebugBreak() {
   __builtin_trap();
 }
 
 
+uintptr_t DART_NOINLINE OS::GetProgramCounter() {
+  return reinterpret_cast<uintptr_t>(
+      __builtin_extract_return_addr(__builtin_return_address(0)));
+}
+
+
 char* OS::StrNDup(const char* s, intptr_t n) {
   return strndup(s, n);
 }
 
 
 intptr_t OS::StrNLen(const char* s, intptr_t n) {
   return strnlen(s, n);
 }
 
 
@@ skipping 116 matching lines @@
 }
 
 
 void OS::Exit(int code) {
   exit(code);
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)