Explicitly specify whether to emit frame pointers by default.

base/debug/stack_trace.h

Index: base/debug/stack_trace.h
diff --git a/base/debug/stack_trace.h b/base/debug/stack_trace.h
index ab1d2ebe6a3c00244b5d09cb1e4fcadce16ab093..7ee1ef557eb86050027e4ed04a687b23aba53187 100644
--- a/base/debug/stack_trace.h
+++ b/base/debug/stack_trace.h
@@ -11,6 +11,7 @@
 #include <string>
 
 #include "base/base_export.h"
+#include "base/debug/debugging_flags.h"
 #include "base/macros.h"
 #include "build/build_config.h"
 
@@ -23,23 +24,14 @@ struct _EXCEPTION_POINTERS;
 struct _CONTEXT;
 #endif
 
-// TODO(699863): Clean up HAVE_TRACE_STACK_FRAME_POINTERS.
-#if defined(OS_POSIX)
-
-#if defined(__i386__) || defined(__x86_64__)
-#define HAVE_TRACE_STACK_FRAME_POINTERS 1
-#elif defined(__arm__) && !defined(__thumb__)
-#define HAVE_TRACE_STACK_FRAME_POINTERS 1
-#else  // defined(__arm__) && !defined(__thumb__)
-#define HAVE_TRACE_STACK_FRAME_POINTERS 0
-#endif  // defined(__arm__) && !defined(__thumb__)
-
-#elif defined(OS_WIN)
-#define HAVE_TRACE_STACK_FRAME_POINTERS 1
-
-#else  // defined(OS_WIN)
-#define HAVE_TRACE_STACK_FRAME_POINTERS 0
-#endif  // defined(OS_WIN)
+// Unwinding using frame pointers requires stack traces to have frame pointers
+// by default. This still doesn't work on thumb architectures, due to an llvm
+// bug. https://bugs.llvm.org/show_bug.cgi?id=18505#c5
+#if ENABLED_FRAME_POINTERS && !(defined(__arm__) && defined(__thumb__))

[brettw, 2017/04/03 21:17:42]

This isn't how you use the buildflag header. So you will want to do
BUILDFLAG(...) and also double-check that this is getting set the way you want.

+#define CAN_UNWIND_WITH_FRAME_POINTERS 1
+#else
+#define CAN_UNWIND_WITH_FRAME_POINTERS 0
+#endif
 
 namespace base {
 namespace debug {
@@ -56,7 +48,7 @@ namespace debug {
 BASE_EXPORT bool EnableInProcessStackDumping();
 
 // Returns end of the stack, or 0 if we couldn't get it.
-#if HAVE_TRACE_STACK_FRAME_POINTERS
+#if CAN_UNWIND_WITH_FRAME_POINTERS
 BASE_EXPORT uintptr_t GetStackEnd();
 #endif
 
@@ -119,7 +111,7 @@ class BASE_EXPORT StackTrace {
   size_t count_;
 };
 
-#if HAVE_TRACE_STACK_FRAME_POINTERS
+#if CAN_UNWIND_WITH_FRAME_POINTERS
 // Traces the stack by using frame pointers. This function is faster but less
 // reliable than StackTrace. It should work for debug and profiling builds,
 // but not for release builds (although there are some exceptions).
@@ -184,7 +176,7 @@ class BASE_EXPORT ScopedStackFrameLinker {
 };
 #endif  // !defined(OS_WIN)
 
-#endif  // HAVE_TRACE_STACK_FRAME_POINTERS
+#endif  // CAN_UNWIND_WITH_FRAME_POINTERS
 
 namespace internal {