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

runtime/include/dart_api.h

 /*
  * Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
  * for details. All rights reserved. Use of this source code is governed by a
  * BSD-style license that can be found in the LICENSE file.
  */
 
 #ifndef INCLUDE_DART_API_H_
 #define INCLUDE_DART_API_H_
 
 /** \mainpage Dart Embedding API Reference
@@ skipping 261 matching lines @@
 /**
  * Gets the exception Object from an unhandled exception error handle.
  */
 DART_EXPORT Dart_Handle Dart_ErrorGetException(Dart_Handle handle);
 
 /**
  * Gets the stack trace Object from an unhandled exception error handle.
  */
 DART_EXPORT Dart_Handle Dart_ErrorGetStacktrace(Dart_Handle handle);
 
+
+/**
+ * Gets the number of frames in a Stacktrace.
+ *
+ * \param handle A Stacktrace.

[siva, 2013/10/31 17:13:26]

maybe call it handle instead of stacktrace.

+ * \param length Returns the frame count.
+ *
+ * \return A valid handle if no error occurs during the operation.
+ */
+DART_EXPORT Dart_Handle Dart_StacktraceLength(Dart_Handle handle,
+                                              intptr_t* length);
+
+/**
+ * Returns information about a given frame in a Stacktrace
+ *
+ * \param handle A Stacktrace.

[siva, 2013/10/31 17:13:26]

Ditto comment.

+ * \param frame_index The position of the frame of the stack. Top-of-stack is at
+ *     position 0.

[siva, 2013/10/31 17:13:26]

position of the frame in the stacktrace?

+ *
+ * \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_Handle handle,
+                            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.
  *
  * Requires there to be a current isolate.
  *
  * \param error the error message.
  */
 DART_EXPORT Dart_Handle Dart_NewApiError(const char* error);
 
 /**
@@ skipping 2020 matching lines @@
  *
  * \param object An object.
  * \param peer A value to store in the peer field.
  *
  * \return Returns an error if 'object' is a subtype of Null, num, or
  *   bool.
  */
 DART_EXPORT Dart_Handle Dart_SetPeer(Dart_Handle object, void* peer);
 
 #endif  /* INCLUDE_DART_API_H_ */  /* NOLINT */