Add function to trace stack using frame pointers.

base/debug/stack_trace.cc

Index: base/debug/stack_trace.cc
diff --git a/base/debug/stack_trace.cc b/base/debug/stack_trace.cc
index 2250c8fb14cc43b76c9a1236f59722b8317a74a2..cedc7be29951e7f75088ab27abb97071ed89d4fe 100644
--- a/base/debug/stack_trace.cc
+++ b/base/debug/stack_trace.cc
@@ -39,5 +39,54 @@ std::string StackTrace::ToString() const {
   return stream.str();
 }
 
+#if HAVE_TRACE_STACK_FRAME_POINTERS
+
+size_t TraceStackFramePointers(const void** out_trace,
+                               size_t max_depth,
+                               size_t skip_initial) {
+  // Usage of __builtin_frame_address() enables frame pointers in this
+  // function even if they are not enabled globally. So 'sp' will always
+  // be valid.
+  uintptr_t sp = reinterpret_cast<uintptr_t>(__builtin_frame_address(0));
+
+  size_t depth = 0;
+  while (depth < max_depth) {
+    if (skip_initial != 0) {
+      skip_initial--;
+    } else {
+      out_trace[depth++] = reinterpret_cast<const void**>(sp)[1];
+    }
+
+#if defined(__arm__) && defined(__GNUC__) && !defined(__clang__)
+    // GCC and LLVM generate slightly different frames on ARM, see
+    // https://llvm.org/bugs/show_bug.cgi?id=18505 - LLVM generates
+    // x86-compatible frame, while GCC needs adjustment.
+    sp -= sizeof(uintptr_t);
+#endif
+
+    // Find out next frame pointer
+    // (heuristics are from TCMalloc's stacktrace functions)
+    {
+      uintptr_t next_sp = reinterpret_cast<const uintptr_t*>(sp)[0];
+
+      // With the stack growing downwards, older stack frame must be
+      // at a greater address that the current one.
+      if (next_sp <= sp) break;
+
+      // Assume stack frames larger than 100,000 bytes are bogus.
+      if (next_sp - sp > 100000) break;
+
+      // Check alignment.
+      if (sp & (sizeof(void*) - 1)) break;
+
+      sp = next_sp;
+    }
+  }
+
+  return depth;
+}
+
+#endif  // HAVE_TRACE_STACK_FRAME_POINTERS
+
 }  // namespace debug
 }  // namespace base