Dart VM: Simplify token positions in the translation of await.

runtime/vm/ast_transformer.cc

 // Copyright (c) 2014, 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/ast_transformer.h"
 
 #include "vm/object_store.h"
 #include "vm/parser.h"
 #include "vm/thread.h"
 
@@ skipping 128 matching lines @@
   LocalVariable* async_catch_error_callback = GetVariableInScope(
       preamble_->scope(), Symbols::AsyncCatchErrorCallback());
   LocalVariable* result_param = GetVariableInScope(
       preamble_->scope(), Symbols::AsyncOperationParam());
   LocalVariable* error_param = GetVariableInScope(
       preamble_->scope(), Symbols::AsyncOperationErrorParam());
   LocalVariable* stack_trace_param = GetVariableInScope(
       preamble_->scope(), Symbols::AsyncOperationStackTraceParam());
 
   AstNode* transformed_expr = Transform(node->expr());
-  LocalVariable* await_temp = AddNewTempVarToPreamble(transformed_expr,
-                                                      ST(node->token_pos()));
+  LocalVariable* await_temp =
+    AddNewTempVarToPreamble(transformed_expr, token_pos);

[hausner, 2016/04/08 16:43:36]

Nit: indentation should be 4 spaces.

 
   AwaitMarkerNode* await_marker =
       new(Z) AwaitMarkerNode(async_temp_scope_, node->scope(), token_pos);
   preamble_->Add(await_marker);
 
   // :result_param = _awaitHelper(
   //      :await_temp, :async_then_callback, :async_catch_error_callback)
   const Library& async_lib = Library::Handle(Library::AsyncLibrary());
   const Function& async_await_helper = Function::ZoneHandle(
       Z, async_lib.LookupFunctionAllowPrivate(Symbols::AsyncAwaitHelper()));
@@ skipping 52 matching lines @@
   error_ne_null_branch->Add(new(Z) ThrowNode(
       token_pos,
       load_error_param,
       load_stack_trace_param));
   preamble_->Add(new(Z) IfNode(
       token_pos,
       new(Z) ComparisonNode(
           token_pos,
           Token::kNE,
           load_error_param,
-          new(Z) LiteralNode(token_pos,
-                              Object::null_instance())),
+          new(Z) LiteralNode(token_pos, Object::null_instance())),
           error_ne_null_branch,
           NULL));
 
-  LocalVariable* result = AddNewTempVarToPreamble(new(Z) LoadLocalNode(
-      token_pos, result_param), ST(node->token_pos()));
-  result_ = new(Z) LoadLocalNode(token_pos, result);
+  result_ = MakeName(result_param);

[hausner, 2016/04/08 16:43:36]

How does this work? result_param is a LocalVariable (line 141), not an AstNode,
as expected by MakeName(). 

 }
 
 
 // Transforms boolean expressions into a sequence of evaluatons that only lazily
 // evaluate subexpressions.
 //
 // Example:
 //
 //   (a || b) only evaluates b if a is false
 //
@@ skipping 330 matching lines @@
 
 
 void AwaitTransformer::VisitThrowNode(ThrowNode* node) {
   AstNode* new_exception = Transform(node->exception());
   result_ = MakeName(new(Z) ThrowNode(node->token_pos(),
       new_exception,
       node->stacktrace()));
 }
 
 }  // namespace dart