Don't print an error when a user-set max frames limit has been reached in the stackwalker

Patch by Julian Seward <jseward@acm.org>, R=ted at https://bugzilla.mozilla.org/show_bug.cgi?id=859745

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1150 4c0a9323-5329-0410-9bdc-e9ce6186880e

2 files changed, 14 insertions, 2 deletions

diff --git a/src/google_breakpad/processor/stackwalker.h b/src/google_breakpad/processor/stackwalker.h
index f09291fe..3640cc73 100644
--- a/src/google_breakpad/processor/stackwalker.h
+++ b/src/google_breakpad/processor/stackwalker.h
@@ -88,7 +88,10 @@ class Stackwalker {
      const CodeModules* modules,
      StackFrameSymbolizer* resolver_helper);
 
-  static void set_max_frames(uint32_t max_frames) { max_frames_ = max_frames; }
+  static void set_max_frames(uint32_t max_frames) {
+    max_frames_ = max_frames;
+    max_frames_set_ = true;
+  }
   static uint32_t max_frames() { return max_frames_; }
 
  protected:
@@ -196,6 +199,11 @@ class Stackwalker {
   // The maximum number of frames Stackwalker will walk through.
   // This defaults to 1024 to prevent infinite loops.
   static uint32_t max_frames_;
+
+  // Keep track of whether max_frames_ has been set by the user, since
+  // it affects whether or not an error message is printed in the case
+  // where an unwind got stopped by the limit.
+  static bool max_frames_set_;
 };
 
 }  // namespace google_breakpad
diff --git a/src/processor/stackwalker.cc b/src/processor/stackwalker.cc
index 076f2e5f..fff3392d 100644
--- a/src/processor/stackwalker.cc
+++ b/src/processor/stackwalker.cc
@@ -58,6 +58,7 @@ namespace google_breakpad {
 
 const int Stackwalker::kRASearchWords = 30;
 uint32_t Stackwalker::max_frames_ = 1024;
+bool Stackwalker::max_frames_set_ = false;
 
 Stackwalker::Stackwalker(const SystemInfo* system_info,
                          MemoryRegion* memory,
@@ -126,7 +127,10 @@ bool Stackwalker::Walk(CallStack* stack,
     // over the frame, because the stack now owns it.
     stack->frames_.push_back(frame.release());
     if (stack->frames_.size() > max_frames_) {
-      BPLOG(ERROR) << "The stack is over " << max_frames_ << " frames.";
+      // Only emit an error message in the case where the limit
+      // reached is the default limit, not set by the user.
+      if (!max_frames_set_)
+        BPLOG(ERROR) << "The stack is over " << max_frames_ << " frames.";
       break;
     }