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

runtime/include/dart_api.h

Index: runtime/include/dart_api.h
diff --git a/runtime/include/dart_api.h b/runtime/include/dart_api.h
index 805737c50417d4fcbb13b6add6b48c06b3dd9e4d..4039f49e54b8c2163fe20b21afd76da814fef248 100755
--- a/runtime/include/dart_api.h
+++ b/runtime/include/dart_api.h
@@ -199,6 +199,8 @@ typedef void (*Dart_WeakPersistentHandleFinalizer)(
     void* peer);
 typedef void (*Dart_PeerFinalizer)(void* peer);
 
+typedef struct _Dart_ExceptionStackTrace* Dart_ExceptionStackTrace;

[rmacnak, 2013/11/07 21:31:12]

This is a bad name considering the Dart_CurrentStacktrace below.

This one should be called Dart_StackTrace, and the one in the debugger should be
renamed Dart_Stack as it is a token for querying a live stack, not a trace.

+
 /**
  * Is this an error handle?
  *
@@ -276,8 +278,58 @@ DART_EXPORT Dart_Handle Dart_ErrorGetException(Dart_Handle handle);
 
 /**
  * Gets the stack trace Object from an unhandled exception error handle.
+ *
+ * \param handle An unhandled exception error.
+ * \param trace Receives the stack trace.
+ *
+ * \return A valid handle if no error occurs during the operation.
  */
-DART_EXPORT Dart_Handle Dart_ErrorGetStacktrace(Dart_Handle handle);
+DART_EXPORT Dart_Handle Dart_ErrorGetStacktrace(

[rmacnak, 2013/11/07 21:31:12]

Note this no longer provides access to dart:core.Stacktrace object.  (It can
still be retrieved using GetField on the exception, but it doesn't provided any
information beyond what can be gotten here.)

+    Dart_Handle handle,
+    Dart_ExceptionStackTrace *trace);
+DART_EXPORT Dart_Handle Dart_CurrentStacktrace(
+    Dart_ExceptionStackTrace *trace);
+
+/**
+ * Gets the number of frames in a stack trace.
+ *
+ * \param trace The stack trace.
+ * \param length Receives the frame count.
+ *
+ * \return A valid handle if no error occurs during the operation.
+ */
+DART_EXPORT Dart_Handle Dart_StacktraceLength(Dart_ExceptionStackTrace trace,
+                                              intptr_t* length);
+
+/**
+ * Returns information about a given frame in a stack trace
+ *
+ * \param trace The stack trace.
+ * \param frame_index The position of the frame in the stacktrace. Top-of-stack
+ *     is at position 0.
+ *
+ * \param function_name receives a string handle with the qualified function
+ *    name.
+ * \param script_url receives a string handle with the url of the source script
+ *    that contains the frame's function.
+ * \param line_number receives the line number in the script.
+ * \param column_number receives the column number in the script, or -1 if
+ *    precise source locations are not available.
+ *
+ * Any or all of the out parameters above may be NULL.
+ *
+ * Requires there to be a current isolate.
+ *
+ * \return A valid handle if no error occurs during the operation.
+ */
+DART_EXPORT Dart_Handle Dart_StacktraceFrameInfo(
+                            Dart_ExceptionStackTrace trace,
+                            intptr_t frame_index,
+                            Dart_Handle* function_name,
+                            Dart_Handle* script_url,
+                            intptr_t* line_number,
+                            intptr_t* column_number);
+
 
 /**
  * Produces an api error handle with the provided error message.