Add Dart_PropagateError.

runtime/vm/longjump.cc

 // Copyright (c) 2011, 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.
 
 #include "vm/longjump.h"
 
 #include "include/dart_api.h"
 
 #include "vm/dart_api_impl.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/os.h"
 
 namespace dart {
 
 jmp_buf* LongJump::Set() {
   top_ = Isolate::Current()->top_resource();
   return &environment_;
 }
 
 
+bool LongJump::IsSafeToJump() {
+  // We do not want to jump past Dart frames.
+  Isolate* isolate = Isolate::Current();
+  uword jumpbuf_addr = reinterpret_cast<uword>(this);
+  return (isolate->top_exit_frame_info() == NULL ||
+          jumpbuf_addr < isolate->top_exit_frame_info());

[siva, 2012/01/31 00:52:34]

This code seems to assume that the stack always grows from high to low, it is
probably true for the targets we port to but it still feels weird.

[turnidge, 2012/01/31 21:56:31]

I also make this assumption in the stack overflow handler in code_generator.cc.

Do you want me to document this?

[siva, 2012/02/01 19:09:38]

Maybe a comment stating that this code assumes the stack grows from high t low
would be fine.

+}
+
+
 void LongJump::Jump(int value, const Error& error) {
   // A zero is the default return value from setting up a LongJump using Set.
   ASSERT(value != 0);
+  ASSERT(IsSafeToJump());
 
   Isolate* isolate = Isolate::Current();
 
   // Remember the error in the sticky error of this isolate.
   isolate->object_store()->set_sticky_error(error);
 
   // Destruct all the active StackResource objects.
   StackResource* current_resource = isolate->top_resource();
   while (current_resource != top_) {
     current_resource->~StackResource();
     current_resource = isolate->top_resource();
   }
   longjmp(environment_, value);
   UNREACHABLE();
 }
 
 }  // namespace dart