1. Add flag --trace-api to trace API function invocation

runtime/lib/stacktrace.cc

Index: runtime/lib/stacktrace.cc
===================================================================
--- runtime/lib/stacktrace.cc	(revision 27164)
+++ runtime/lib/stacktrace.cc	(working copy)
@@ -30,18 +30,9 @@
 }
 
 
-// Setup a full stack trace.
-// Arg0: stack trace object.
-// Return value: None.
-DEFINE_NATIVE_ENTRY(Stacktrace_setupFullStacktrace, 1) {
-  const Stacktrace& trace =
-      Stacktrace::CheckedHandle(arguments->NativeArgAt(0));
-  const GrowableObjectArray& func_list =
-      GrowableObjectArray::Handle(GrowableObjectArray::New());
-  const GrowableObjectArray& code_list =
-      GrowableObjectArray::Handle(GrowableObjectArray::New());
-  const GrowableObjectArray& pc_offset_list =
-      GrowableObjectArray::Handle(GrowableObjectArray::New());
+static void iterateFrames(const GrowableObjectArray& func_list,
+                          const GrowableObjectArray& code_list,
+                          const GrowableObjectArray& pc_offset_list) {
   StackFrameIterator frames(StackFrameIterator::kDontValidateFrames);
   StackFrame* frame = frames.NextFrame();
   ASSERT(frame != NULL);  // We expect to find a dart invocation frame.
@@ -90,6 +81,22 @@
     }
     frame = frames.NextFrame();
   }
+}
+
+
+// Setup a full stack trace.
+// Arg0: stack trace object.
+// Return value: None.
+DEFINE_NATIVE_ENTRY(Stacktrace_setupFullStacktrace, 1) {
+  const Stacktrace& trace =
+      Stacktrace::CheckedHandle(arguments->NativeArgAt(0));
+  const GrowableObjectArray& func_list =
+      GrowableObjectArray::Handle(GrowableObjectArray::New());
+  const GrowableObjectArray& code_list =
+      GrowableObjectArray::Handle(GrowableObjectArray::New());
+  const GrowableObjectArray& pc_offset_list =
+      GrowableObjectArray::Handle(GrowableObjectArray::New());
+  iterateFrames(func_list, code_list, pc_offset_list);
   const Array& func_array = Array::Handle(Array::MakeArray(func_list));
   const Array& code_array = Array::Handle(Array::MakeArray(code_list));
   const Array& pc_offset_array =
@@ -98,4 +105,27 @@
   return Object::null();
 }
 
+
+// An utility method for convenient printing of dart stack traces when
+// inside 'gdb'. Note: This function will only work when there is a
+// valid exit frame information. It will not work when a breakpoint is
+// set in dart code and control is got inside 'gdb' without going through
+// the runtime or native transition stub.
+void _printCurrentStacktrace() {
+  const GrowableObjectArray& func_list =
+      GrowableObjectArray::Handle(GrowableObjectArray::New());
+  const GrowableObjectArray& code_list =
+      GrowableObjectArray::Handle(GrowableObjectArray::New());
+  const GrowableObjectArray& pc_offset_list =
+      GrowableObjectArray::Handle(GrowableObjectArray::New());
+  iterateFrames(func_list, code_list, pc_offset_list);
+  const Array& func_array = Array::Handle(Array::MakeArray(func_list));
+  const Array& code_array = Array::Handle(Array::MakeArray(code_list));
+  const Array& pc_offset_array =
+      Array::Handle(Array::MakeArray(pc_offset_list));
+  const Stacktrace& stacktrace = Stacktrace::Handle(
+      Stacktrace::New(func_array, code_array, pc_offset_array));
+  OS::Print("%s\n", stacktrace.ToCString());
+}
+
 }  // namespace dart