Handle overwriting valueOf on String objects correctly when adding...

src/arm/full-codegen-arm.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1941 matching lines @@
   __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
   __ ldrb(r1, FieldMemOperand(r1, Map::kBitFieldOffset));
   __ tst(r1, Operand(1 << Map::kIsUndetectable));
   __ b(ne, if_true);
   __ b(if_false);
 
   Apply(context_, if_true, if_false);
 }
 
 
+void FullCodeGenerator::EmitIsStringWrapperSafeForDefaultValueOf(
+    ZoneList<Expression*>* args) {
+
+  ASSERT(args->length() == 1);
+
+  VisitForValue(args->at(0), kAccumulator);
+
+  Label materialize_true, materialize_false;
+  Label* if_true = NULL;
+  Label* if_false = NULL;
+  PrepareTest(&materialize_true, &materialize_false, &if_true, &if_false);
+
+  // Just indicate false, as %_IsStringWrapperSafeForDefaultValueOf() is only
+  // used in a few functions in runtime.js which should not normally be hit by
+  // this compiler.
+  __ jmp(if_false);
+  Apply(context_, if_true, if_false);
+}
+
+
 void FullCodeGenerator::EmitIsFunction(ZoneList<Expression*>* args) {
   ASSERT(args->length() == 1);
 
   VisitForValue(args->at(0), kAccumulator);
 
   Label materialize_true, materialize_false;
   Label* if_true = NULL;
   Label* if_false = NULL;
   PrepareTest(&materialize_true, &materialize_false, &if_true, &if_false);
 
@@ skipping 1249 matching lines @@
   __ mov(r1, Operand(r1, ASR, 1));  // Un-smi-tag value.
   __ add(pc, r1, Operand(masm_->CodeObject()));
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM