Adds TCMalloc support for Android.

third_party/tcmalloc/chromium/src/stacktrace_android-inl.h

Index: third_party/tcmalloc/chromium/src/stacktrace_android-inl.h
diff --git a/third_party/tcmalloc/vendor/src/stacktrace_generic-inl.h b/third_party/tcmalloc/chromium/src/stacktrace_android-inl.h
similarity index 61%
copy from third_party/tcmalloc/vendor/src/stacktrace_generic-inl.h
copy to third_party/tcmalloc/chromium/src/stacktrace_android-inl.h
index 5a526e228a1164853c1c327f9ce72e67ddb6a787..aedcc268e310d872148c05bba9b606bf96a25466 100644
--- a/third_party/tcmalloc/vendor/src/stacktrace_generic-inl.h
+++ b/third_party/tcmalloc/chromium/src/stacktrace_android-inl.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2005, Google Inc.
+// Copyright (c) 2013, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
@@ -28,22 +28,60 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // ---
-// Author: Sanjay Ghemawat
+// Author: Marcus Bulach
+// This is inspired by Doug Kwan's ARM's stacktrace code.
 //
-// Portable implementation - just use glibc
-//
-// Note:  The glibc implementation may cause a call to malloc.
-// This can cause a deadlock in HeapProfiler.
 
-#ifndef BASE_STACKTRACE_GENERIC_INL_H_
-#define BASE_STACKTRACE_GENERIC_INL_H_
+#ifndef BASE_STACKTRACE_ANDROID_INL_H_
+#define BASE_STACKTRACE_ANDROID_INL_H_
 // Note: this file is included into stacktrace.cc more than once.
 // Anything that should only be defined once should be here:
 
-#include <execinfo.h>
-#include <string.h>
-#include "gperftools/stacktrace.h"
-#endif  // BASE_STACKTRACE_GENERIC_INL_H_
+#include <stdint.h>   // for uintptr_t
+#include <unwind.h>

[Dai Mikurube (NOT FULLTIME), 2013/05/03 11:02:35]

Import comments mentioning http://crbug.com/236855.

[bulach, 2013/05/07 14:55:51]

Done.

+
+typedef _Unwind_Context __unwind_context;
+
+struct stack_crawl_state_t {
+  uintptr_t* frames;
+  size_t frame_count;
+  int max_depth;
+  int skip_count;
+  bool have_skipped_self;
+
+  stack_crawl_state_t(uintptr_t* frames, int max_depth, int skip_count)
+      : frames(frames),
+        frame_count(0),
+        max_depth(max_depth),
+        skip_count(skip_count),
+        have_skipped_self(false) {
+  }
+};
+
+static _Unwind_Reason_Code tracer(__unwind_context* context, void* arg) {
+  stack_crawl_state_t* state = static_cast<stack_crawl_state_t*>(arg);
+
+  uintptr_t ip = _Unwind_GetIP(context);

[Dai Mikurube (NOT FULLTIME), 2013/05/03 11:02:35]

Need to import the hack for Clang.  (See the latest patch
https://codereview.chromium.org/14646012/.  Some portions are changed.)

[bulach, 2013/05/07 14:55:51]

Done.

+
+  // The first stack frame is this function itself.  Skip it.
+  if (ip != 0 && !state->have_skipped_self) {
+    state->have_skipped_self = true;
+    return _URC_NO_REASON;
+  }
+
+  if (state->skip_count) {
+    --state->skip_count;
+    return _URC_NO_REASON;
+  }
+
+  state->frames[state->frame_count++] = ip;
+  if (state->frame_count >= state->max_depth)
+    return _URC_END_OF_STACK;
+  else
+    return _URC_NO_REASON;
+}
+
+#endif  // BASE_STACKTRACE_ANDROID_INL_H_
 
 // Note: this part of the file is included several times.
 // Do not put globals below.
@@ -60,24 +98,7 @@
 //   int skip_count: how many stack pointers to skip before storing in result
 //   void* ucp: a ucontext_t* (GetStack{Trace,Frames}WithContext only)
 int GET_STACK_TRACE_OR_FRAMES {
-  static const int kStackLength = 64;
-  void * stack[kStackLength];
-  int size;
-
-  size = backtrace(stack, kStackLength);
-  skip_count++;  // we want to skip the current frame as well
-  int result_count = size - skip_count;
-  if (result_count < 0)
-    result_count = 0;
-  if (result_count > max_depth)
-    result_count = max_depth;
-  for (int i = 0; i < result_count; i++)
-    result[i] = stack[i + skip_count];
-
-#if IS_STACK_FRAMES
-  // No implementation for finding out the stack frame sizes yet.
-  memset(sizes, 0, sizeof(*sizes) * result_count);
-#endif
-
-  return result_count;
+  stack_crawl_state_t state(
+    reinterpret_cast<uintptr_t*>(result), max_depth, skip_count);

[Dai Mikurube (NOT FULLTIME), 2013/05/03 11:02:35]

nit: indent by 4

[bulach, 2013/05/07 14:55:51]

Done.

+  _Unwind_Backtrace(tracer, &state);

[Dai Mikurube (NOT FULLTIME), 2013/05/03 11:02:35]

We need
return state.frame_count;
here.  (It's the reason why the lengths of backtraces were always 5.)

[bulach, 2013/05/07 14:55:51]

ahn, great!!! done.

 }