Fix for running with --throw_on_javascript_int_overflow: recognize pattern (a << b) & mask and test…

runtime/vm/ast.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_AST_H_
 #define VM_AST_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
@@ skipping 551 matching lines @@
   DISALLOW_IMPLICIT_CONSTRUCTORS(ComparisonNode);
 };
 
 
 class BinaryOpNode : public AstNode {
  public:
   BinaryOpNode(intptr_t token_pos,
                Token::Kind kind,
                AstNode* left,
                AstNode* right)
-      : AstNode(token_pos), kind_(kind), left_(left), right_(right) {
+      : AstNode(token_pos),
+        kind_(kind),
+        left_(left),
+        right_(right),
+        mask32_(-1) {
     ASSERT(left_ != NULL);
     ASSERT(right_ != NULL);
     ASSERT(IsKindValid());
   }
 
   Token::Kind kind() const { return kind_; }
   AstNode* left() const { return left_; }
   AstNode* right() const { return right_; }
 
+  // The optional 32-bit mask must be a an unsigned 32-bit value.
+  bool has_mask32() const { return mask32_ >= 0; }
+  int64_t mask32() const {
+    ASSERT(has_mask32());
+    return mask32_;
+  }
+  void set_mask32(int64_t value) {
+    ASSERT(Utils::IsUint(32, value));
+    mask32_ = value;
+  }
+
   virtual void VisitChildren(AstNodeVisitor* visitor) const {
     left()->Visit(visitor);
     right()->Visit(visitor);
   }
 
   virtual const char* Name() const;
   virtual bool IsPotentiallyConst() const;
   virtual const Instance* EvalConstExpr() const;
 
   DECLARE_COMMON_NODE_FUNCTIONS(BinaryOpNode);
 
  private:
   const Token::Kind kind_;
   AstNode* left_;
   AstNode* right_;
+  // Optional unsigned 32 bit mask applied on result. No mask: -1.
+  int64_t mask32_;

[Florian Schneider, 2013/08/13 15:29:52]

I think it would be cleaner to have a separate AST node. It would also avoid
adding 64 bit to all the binary op nodes.

[srdjan, 2013/08/13 18:44:59]

Done.

 
   bool IsKindValid() const;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(BinaryOpNode);
 };
 
 
 class UnaryOpNode : public AstNode {
  public:
   // Returns optimized version, e.g., for ('-' '1') ('-1') literal is returned.
@@ skipping 1103 matching lines @@
   const intptr_t try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(InlinedFinallyNode);
 };
 
 }  // namespace dart
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
 #endif  // VM_AST_H_