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

runtime/vm/parser.cc

 // 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.
 
 #include "vm/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
@@ skipping 7272 matching lines @@
       if (binary_op == Token::kDIV) {
         const Double& dbl_obj = Double::ZoneHandle(
             Double::NewCanonical((left_double / right_double)));
         return new LiteralNode(op_pos, dbl_obj);
       }
     }
   }
   if ((binary_op == Token::kAND) || (binary_op == Token::kOR)) {
     EnsureExpressionTemp();
   }
+  if (binary_op == Token::kBIT_AND) {
+    // Normalize so that rhs is a literal if any is.
+    if ((rhs_literal == NULL) && (lhs_literal != NULL)) {
+      // Swap.
+      LiteralNode* temp = rhs_literal;
+      rhs_literal = lhs_literal;
+      lhs_literal = temp;
+    }
+    if ((rhs_literal != NULL) &&
+        (rhs_literal->literal().IsSmi() || rhs_literal->literal().IsMint())) {
+      const int64_t val = Integer::Cast(rhs_literal->literal()).AsInt64Value();
+      if ((0 <= val) && (Utils::IsUint(32, val))) {
+        if (lhs->IsBinaryOpNode() &&
+            (lhs->AsBinaryOpNode()->kind() == Token::kSHL)) {
+          // Merge SHL and BIT_AND into one "SHL with mask" node.
+          BinaryOpNode* old = lhs->AsBinaryOpNode();
+          BinaryOpWithMask32Node* binop = new BinaryOpWithMask32Node(
+              old->token_pos(), old->kind(), old->left(), old->right(), val);
+          return binop;
+        }
+      }
+    }
+  }
   return new BinaryOpNode(op_pos, binary_op, lhs, rhs);
 }
 
 
 AstNode* Parser::ExpandAssignableOp(intptr_t op_pos,
                                     Token::Kind assignment_op,
                                     AstNode* lhs,
                                     AstNode* rhs) {
   TRACE_PARSER("ExpandAssignableOp");
   switch (assignment_op) {
@@ skipping 3017 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart