Add an API function to get a debugger stack trace from an error handle.

runtime/vm/debugger_api_impl.cc

Index: runtime/vm/debugger_api_impl.cc
diff --git a/runtime/vm/debugger_api_impl.cc b/runtime/vm/debugger_api_impl.cc
index c20bf670a12307a11a992be55ababd04ab5b44e7..17ffe27bf300fadefa70acb2bec5c76cd7175671 100644
--- a/runtime/vm/debugger_api_impl.cc
+++ b/runtime/vm/debugger_api_impl.cc
@@ -221,11 +221,38 @@ DART_EXPORT Dart_Handle Dart_GetStackTrace(Dart_StackTrace* trace) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   CHECK_NOT_NULL(trace);
-  *trace = reinterpret_cast<Dart_StackTrace>(isolate->debugger()->StackTrace());
+  *trace = reinterpret_cast<Dart_StackTrace>(
+      isolate->debugger()->UncachedStackTrace());
   return Api::Success();
 }
 
 
+DART_EXPORT Dart_Handle Dart_GetStackTraceFromError(Dart_Handle handle,
+                                                    Dart_StackTrace* trace) {
+  Isolate* isolate = Isolate::Current();
+  DARTSCOPE(isolate);
+  CHECK_NOT_NULL(trace);
+  const Object& obj = Object::Handle(isolate, Api::UnwrapHandle(handle));
+  if (obj.IsUnhandledException()) {
+    const UnhandledException& error = UnhandledException::Cast(obj);
+    Stacktrace& dart_stacktrace = Stacktrace::Handle(isolate);
+    dart_stacktrace ^= error.stacktrace();
+    if (dart_stacktrace.IsNull()) {
+      *trace = NULL;
+    } else {
+      *trace = reinterpret_cast<Dart_StackTrace>(
+        isolate->debugger()->StackTraceFrom(dart_stacktrace));
+    }
+    return Api::Success();
+  } else if (obj.IsError()) {
+    return Api::NewError("This error is not an unhandled exception error.");

[siva, 2013/11/12 16:00:43]

Why are you not getting the stack trace corresponding to the error object? All
error objects have a stack trace.

You could unwrap into an error object:

const Error& error = Api::UnwrapErrorHandle(isolate, handle);
if (error.IsNull()) {
  return Api::NewError("Can only ......");
}
...
...

[rmacnak, 2013/11/12 22:32:40]

This matches the behavior of Dart_ErrorGetStacktrace. It would be strange for
this path to be exercised. Someone would have to catch an error, and then pass
it into a native. I'd rather not add such functionality as part of this CL.

+  } else {
+    return Api::NewError("Can only get stacktraces from error handles.");
+  }
+}
+
+
+
 DART_EXPORT Dart_Handle Dart_ActivationFrameInfo(
                             Dart_ActivationFrame activation_frame,
                             Dart_Handle* function_name,
@@ -251,6 +278,30 @@ DART_EXPORT Dart_Handle Dart_ActivationFrameInfo(
   return Api::Success();
 }
 
+DART_EXPORT Dart_Handle Dart_ActivationFrameInfoWithColumn(
+                            Dart_ActivationFrame activation_frame,
+                            Dart_Handle* function_name,
+                            Dart_Handle* script_url,
+                            intptr_t* line_number,
+                            intptr_t* column_number) {
+  Isolate* isolate = Isolate::Current();
+  DARTSCOPE(isolate);
+  CHECK_AND_CAST(ActivationFrame, frame, activation_frame);
+  if (function_name != NULL) {
+    *function_name = Api::NewHandle(isolate, frame->QualifiedFunctionName());
+  }
+  if (script_url != NULL) {
+    *script_url = Api::NewHandle(isolate, frame->SourceUrl());
+  }
+  if (line_number != NULL) {
+    *line_number = frame->LineNumber();
+  }
+  if (column_number != NULL) {
+    *column_number = frame->ColumnNumber();
+  }
+  return Api::Success();
+}
+
 
 DART_EXPORT Dart_Handle Dart_ActivationFrameGetLocation(
                             Dart_ActivationFrame activation_frame,