Fix capturing variables in optimized compilations

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
diff --git a/runtime/vm/parser.cc b/runtime/vm/parser.cc
index 2ec2a489374abba8da7ebbeb7afe77f8a30383d8..e75934499b0ef021efd354d00c865d510b49959f 100644
--- a/runtime/vm/parser.cc
+++ b/runtime/vm/parser.cc
@@ -7612,6 +7612,7 @@ AstNode* Parser::ParseFunctionStatement(bool is_literal) {
   // Note that we cannot share the same closure function between the closurized
   // and non-closurized versions of the same parent function.
   Function& function = Function::ZoneHandle(Z);
+  bool found_func = true;
   // TODO(hausner): There could be two different closures at the given
   // function_pos, one enclosed in a closurized function and one enclosed in the
   // non-closurized version of this same function.
@@ -7620,6 +7621,7 @@ AstNode* Parser::ParseFunctionStatement(bool is_literal) {
     // The function will be registered in the lookup table by the
     // EffectGraphVisitor::VisitClosureNode when the newly allocated closure
     // function has been properly setup.
+    found_func = false;
     function = Function::NewClosureFunction(*function_name,
                                             innermost_function(),
                                             function_pos);
@@ -7669,15 +7671,38 @@ AstNode* Parser::ParseFunctionStatement(bool is_literal) {
     }
   }
 
-  // Parse the local function.
-  SequenceNode* statements = Parser::ParseFunc(function, !is_literal);
-  INC_STAT(thread(), num_functions_parsed, 1);
 
-  // Now that the local function has formal parameters, lookup the signature
-  Type& signature_type = Type::ZoneHandle(Z, function.SignatureType());
-  signature_type ^= ClassFinalizer::FinalizeType(
-      current_class(), signature_type, ClassFinalizer::kCanonicalize);
-  function.SetSignatureType(signature_type);
+  Type& signature_type = Type::ZoneHandle(Z);
+  SequenceNode* statements = NULL;
+  if (!found_func) {
+    // Parse the local function. As a side effect of the parsing, the
+    // variables of this function's scope that are referenced by the local
+    // function (and its inner nested functions) will be marked as captured.
+    statements = Parser::ParseFunc(function, !is_literal);
+    INC_STAT(thread(), num_functions_parsed, 1);
+
+    // Now that the local function has formal parameters, lookup the signature
+    signature_type = function.SignatureType();
+    signature_type ^= ClassFinalizer::FinalizeType(
+        current_class(), signature_type, ClassFinalizer::kCanonicalize);
+    function.SetSignatureType(signature_type);
+  } else {
+    // The local function was parsed before. The captrued variables are

[regis, 2016/05/16 22:42:15]

captured

+    // saved in the function's context scope. Iterate over the context scope
+    // and mark its variables as captured.
+    const ContextScope& context_scope =
+        ContextScope::Handle(Z, function.context_scope());
+    ASSERT(!context_scope.IsNull());
+    String& var_name = String::Handle(Z);
+    for (int i = 0; i < context_scope.num_variables(); i++) {
+      var_name = context_scope.NameAt(i);
+      LocalVariable* v = LookupLocalScope(var_name);
+      ASSERT(v != NULL);
+      current_block_->scope->CaptureVariable(v);
+    }
+    SkipFunctionLiteral();
+    signature_type = function.SignatureType();
+  }
 
   // Local functions are registered in the enclosing class, but
   // ignored during class finalization. The enclosing class has
@@ -7732,8 +7757,9 @@ AstNode* Parser::ParseFunctionStatement(bool is_literal) {
   // variables are not relevant for the compilation of the enclosing function.
   // This pruning is done by omitting to hook the local scope in its parent
   // scope in the constructor of LocalScope.
-  AstNode* closure = new(Z) ClosureNode(
-      function_pos, function, NULL, statements->scope());
+  AstNode* closure =
+      new(Z) ClosureNode(function_pos, function, NULL,
+                         statements != NULL ? statements->scope() : NULL);
 
   if (function_variable == NULL) {
     ASSERT(is_literal);