Adding unit tests for profiler's stack tracer.

src/log.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 116 matching lines @@
   bool running_;
 
   // Tells whether we are currently recording tick samples.
   static bool paused_;
 };
 
 bool Profiler::paused_ = false;
 
 
 //
+// StackTracer implementation
+//
+void StackTracer::Trace(TickSample* sample) {
+  // Assuming that stack grows from lower addresses
+  if (sample->sp < sample->fp && sample->fp < low_stack_bound_) {
+    sample->InitStack(1);
+    sample->stack[0] = Memory::Address_at(
+        (Address)(sample->fp + StandardFrameConstants::kCallerPCOffset));
+  } else {
+    // FP seems to be in some intermediate state, better discard this sample
+    sample->InitStack(0);
+  }
+}
+
+
+//
 // Ticker used to provide ticks to the profiler and the sliding state
 // window.
 //
 class Ticker: public Sampler {
  public:
   explicit Ticker(int interval, unsigned int low_stack_bound):
       Sampler(interval, FLAG_prof), window_(NULL), profiler_(NULL),
-      low_stack_bound_(low_stack_bound) {}
+      stack_tracer_(low_stack_bound) {}
 
   ~Ticker() { if (IsActive()) Stop(); }
 
   void Tick(TickSample* sample) {
-    if (IsProfiling()) SampleStack(sample);
+    if (IsProfiling()) stack_tracer_.Trace(sample);
     if (profiler_) profiler_->Insert(sample);
     if (window_) window_->AddState(sample->state);
   }
 
   void SetWindow(SlidingStateWindow* window) {
     window_ = window;
     if (!IsActive()) Start();
   }
 
   void ClearWindow() {
     window_ = NULL;
     if (!profiler_ && IsActive()) Stop();
   }
 
   void SetProfiler(Profiler* profiler) {
     profiler_ = profiler;
     if (!IsActive()) Start();
   }
 
   void ClearProfiler() {
     profiler_ = NULL;
     if (!window_ && IsActive()) Stop();
   }
 
  private:
-  void SampleStack(TickSample* sample) {
-    // Assuming that stack grows from lower addresses
-    if (sample->sp < sample->fp && sample->fp < low_stack_bound_) {
-      sample->InitStack(1);
-      sample->stack[0] = Memory::Address_at(
-          (Address)(sample->fp + StandardFrameConstants::kCallerPCOffset));
-    } else {
-      // FP seems to be in some intermediate state, better discard this sample
-      sample->InitStack(0);
-    }
-  }
-
   SlidingStateWindow* window_;
   Profiler* profiler_;
-  unsigned int low_stack_bound_;
+  StackTracer stack_tracer_;
 };
 
 
 //
 // SlidingStateWindow implementation.
 //
 SlidingStateWindow::SlidingStateWindow(): current_index_(0), is_full_(false) {
   for (int i = 0; i < kBufferSize; i++) {
     buffer_[i] = static_cast<byte>(OTHER);
   }
@@ skipping 930 matching lines @@
   if (FLAG_log_state_changes) {
     LOG(UncheckedStringEvent("Leaving", StateToString(state_)));
     if (previous_) {
       LOG(UncheckedStringEvent("To", StateToString(previous_->state_)));
     }
   }
 }
 #endif
 
 } }  // namespace v8::internal