Fix scoping async functions.

runtime/vm/parser.h

Index: runtime/vm/parser.h
diff --git a/runtime/vm/parser.h b/runtime/vm/parser.h
index d249655e9947fd59f05c10031ed9d09a4c967015..258a00994498fc7648f79cc41b5795822031b18a 100644
--- a/runtime/vm/parser.h
+++ b/runtime/vm/parser.h
@@ -48,7 +48,6 @@ class ParsedFunction : public ZoneAllocated {
         saved_entry_context_var_(NULL),
         expression_temp_var_(NULL),
         finally_return_temp_var_(NULL),
-        await_temps_scope_(NULL),
         deferred_prefixes_(new ZoneGrowableArray<const LibraryPrefix*>()),
         first_parameter_index_(0),
         first_stack_local_index_(0),
@@ -56,7 +55,7 @@ class ParsedFunction : public ZoneAllocated {
         num_stack_locals_(0),
         have_seen_await_expr_(false),
         saved_try_ctx_(NULL),
-        async_saved_try_ctx_(NULL),
+        async_saved_try_ctx_name_(String::ZoneHandle(isolate, String::null())),
         isolate_(isolate) {
     ASSERT(function.IsZoneHandle());
   }
@@ -142,15 +141,6 @@ class ParsedFunction : public ZoneAllocated {
 
   void AllocateVariables();
 
-  void set_await_temps_scope(LocalScope* scope) {
-    ASSERT(await_temps_scope_ == NULL);
-    await_temps_scope_ = scope;
-  }
-  LocalScope* await_temps_scope() const {
-    ASSERT(await_temps_scope_ != NULL);
-    return await_temps_scope_;
-  }
-
   void record_await() {
     have_seen_await_expr_ = true;
   }
@@ -158,20 +148,21 @@ class ParsedFunction : public ZoneAllocated {
   bool have_seen_await() const { return have_seen_await_expr_; }
 
   void set_saved_try_ctx(LocalVariable* saved_try_ctx) {
-    ASSERT((saved_try_ctx != NULL) && !saved_try_ctx->is_captured());
+    ASSERT((saved_try_ctx == NULL) || !saved_try_ctx->is_captured());
     saved_try_ctx_ = saved_try_ctx;
   }
   LocalVariable* saved_try_ctx() const { return saved_try_ctx_; }
 
-  void set_async_saved_try_ctx(LocalVariable* async_saved_try_ctx) {
-    ASSERT((async_saved_try_ctx != NULL) && async_saved_try_ctx->is_captured());
-    async_saved_try_ctx_ = async_saved_try_ctx;
+  void set_async_saved_try_ctx_name(const String& async_saved_try_ctx_name) {
+    async_saved_try_ctx_name_ = async_saved_try_ctx_name.raw();
+  }
+  RawString* async_saved_try_ctx_name() const {
+    return async_saved_try_ctx_name_.raw();
   }
-  LocalVariable* async_saved_try_ctx() const { return async_saved_try_ctx_; }
 
   void reset_saved_try_ctx_vars() {
     saved_try_ctx_ = NULL;
-    async_saved_try_ctx_ = NULL;
+    async_saved_try_ctx_name_ = String::null();
   }
 
   Isolate* isolate() const { return isolate_; }
@@ -186,7 +177,6 @@ class ParsedFunction : public ZoneAllocated {
   LocalVariable* saved_entry_context_var_;
   LocalVariable* expression_temp_var_;
   LocalVariable* finally_return_temp_var_;
-  LocalScope* await_temps_scope_;
   ZoneGrowableArray<const LibraryPrefix*>* deferred_prefixes_;
 
   int first_parameter_index_;
@@ -195,7 +185,7 @@ class ParsedFunction : public ZoneAllocated {
   int num_stack_locals_;
   bool have_seen_await_expr_;
   LocalVariable* saved_try_ctx_;
-  LocalVariable* async_saved_try_ctx_;
+  String& async_saved_try_ctx_name_;

[Michael Lippautz (Google), 2014/09/02 18:22:11]

It's not ideal that we need to save the symbol in the one case and the variable
in the other... 

We need to look up the async version though as the try/catch/finally might live
in a context level further down.

 
   Isolate* isolate_;
 
@@ -557,6 +547,7 @@ class Parser : public ValueObject {
   SequenceNode* CloseAsyncFunction(const Function& closure,
                                    SequenceNode* closure_node);
   void CloseAsyncClosure(SequenceNode* body);
+  void AddAsyncClosureVariables();
 
 
   LocalVariable* LookupPhaseParameter();
@@ -731,9 +722,10 @@ class Parser : public ValueObject {
                                   InvocationMirror::Type type,
                                   const Function* func);
 
-  void SetupSavedTryContext(LocalScope* saved_try_context_scope,
-                            int16_t try_index,
-                            SequenceNode* target);
+  void SetupSavedTryContext(LocalVariable* saved_try_context);
+  void RestoreSavedTryContext(LocalScope* saved_try_context_scope,
+                              int16_t try_index,
+                              SequenceNode* target);
 
   void CheckOperatorArity(const MemberDesc& member);
 
@@ -817,6 +809,8 @@ class Parser : public ValueObject {
 
   bool unregister_pending_function_;
 
+  LocalScope* async_temp_scope_;
+
   DISALLOW_COPY_AND_ASSIGN(Parser);
 };