Enter and Exit scope when calling into the native library tag handler

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
===================================================================
--- runtime/vm/parser.cc	(revision 32333)
+++ runtime/vm/parser.cc	(working copy)
@@ -4855,7 +4855,20 @@
 }
 
 
+class DartApiScope : public StackResource {
+ public:
+  explicit DartApiScope(Isolate* isolate) : StackResource(isolate) {
+    Dart_EnterScope();
+  }
+  ~DartApiScope() {
+    Dart_ExitScope();
+  }
 
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DartApiScope);
+};
+
+
 RawObject* Parser::CallLibraryTagHandler(Dart_LibraryTag tag,
                                          intptr_t token_pos,
                                          const String& url) {
@@ -4872,6 +4885,7 @@
   // Block class finalization attempts when calling into the library
   // tag handler.
   isolate()->BlockClassFinalization();
+  DartApiScope api_scope(isolate());

[hausner, 2014/02/05 22:22:56]

If this is the only place you anticipate calls to enter/exit scope, it might be
a bit of overkill to introduce the class above.

[siva, 2014/02/05 23:10:55]

The reason I made it a class is because we have some calls to ErrorMessage which
do a long jump and out and we want this to be a stack resorce that gets cleaned
out.

On 2014/02/05 22:22:56, hausner wrote:

   Dart_Handle result = handler(tag,
                                Api::NewHandle(isolate(), library_.raw()),
                                Api::NewHandle(isolate(), url.raw()));