Eliminate temporary locals for some expressions

runtime/vm/ast.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/ast.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/isolate.h"
 #include "vm/object_store.h"
 #include "vm/resolver.h"
@@ skipping 55 matching lines @@
 }
 
 
 void ArgumentListNode::VisitChildren(AstNodeVisitor* visitor) const {
   for (intptr_t i = 0; i < this->length(); i++) {
     NodeAt(i)->Visit(visitor);
   }
 }
 
 
+LetNode::LetNode(intptr_t token_pos, intptr_t num_temps)
+  : AstNode(token_pos),
+    vars_(num_temps),
+    temp_expressions_(num_temps),
+    body_(NULL) {
+  for (intptr_t i = 0; i < num_temps; ++i) {
+    char name[64];
+    OS::SNPrint(name, 64, ":lt%"Pd"_%"Pd, token_pos, i);

[hausner, 2013/05/28 17:00:47]

64 -> sizeof name

For our own debugging purposes, might be nice to separate the token position and
the temp index with an _ or some other character.

[Florian Schneider, 2013/05/30 09:29:31]

Done.

+    vars_.Add(
+        new LocalVariable(token_pos,
+                          String::ZoneHandle(Symbols::New(name)),
+                          Type::ZoneHandle(Type::DynamicType())));
+    temp_expressions_.Add(NULL);
+  }
+}
+
+
+void LetNode::VisitChildren(AstNodeVisitor* visitor) const {
+  for (intptr_t i = 0; i < num_temps(); ++i) {
+    temp_expressions_[i]->Visit(visitor);
+  }
+  body_->Visit(visitor);
+}
+
+
 void ArrayNode::VisitChildren(AstNodeVisitor* visitor) const {
   for (intptr_t i = 0; i < this->length(); i++) {
     ElementAt(i)->Visit(visitor);
   }
 }
 
 
 // TODO(srdjan): Add code for logical negation.
 AstNode* LiteralNode::ApplyUnaryOp(Token::Kind unary_op_kind) {
   if (unary_op_kind == Token::kNEGATE) {
@@ skipping 344 matching lines @@
   if (result.IsError() || result.IsNull()) {
     // TODO(turnidge): We could get better error messages by returning
     // the Error object directly to the parser.  This will involve
     // replumbing all of the EvalConstExpr methods.
     return NULL;
   }
   return &Instance::ZoneHandle(Instance::Cast(result).raw());
 }
 
 }  // namespace dart