Strict mode arguments do not share binding with formal parameters.

src/arm/codegen-arm.cc

 // Copyright 2010 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 559 matching lines @@
   Register reg = frame_->GetTOSRegister();
   __ ldr(reg, ContextOperand(cp, Context::GLOBAL_INDEX));
   __ ldr(reg,
          FieldMemOperand(reg, GlobalObject::kGlobalReceiverOffset));
   frame_->EmitPush(reg);
 }
 
 
 ArgumentsAllocationMode CodeGenerator::ArgumentsMode() {
   if (scope()->arguments() == NULL) return NO_ARGUMENTS_ALLOCATION;
-  ASSERT(scope()->arguments_shadow() != NULL);
+
+  // In strict mode there is no need for shadow arguments.
+  ASSERT(scope()->arguments_shadow() != NULL || scope()->is_strict_mode());
   // We don't want to do lazy arguments allocation for functions that
   // have heap-allocated contexts, because it interfers with the
   // uninitialized const tracking in the context objects.
-  return (scope()->num_heap_slots() > 0)
+  return (scope()->num_heap_slots() > 0 || scope()->is_strict_mode())
       ? EAGER_ARGUMENTS_ALLOCATION
       : LAZY_ARGUMENTS_ALLOCATION;
 }
 
 
 void CodeGenerator::StoreArgumentsObject(bool initial) {
   ArgumentsAllocationMode mode = ArgumentsMode();
   ASSERT(mode != NO_ARGUMENTS_ALLOCATION);
 
   Comment cmnt(masm_, "[ store arguments object");
@@ skipping 13 matching lines @@
     __ mov(r0, Operand(Smi::FromInt(scope()->num_parameters())));
     frame_->Adjust(3);
     __ Push(r2, r1, r0);
     frame_->CallStub(&stub, 3);
     frame_->EmitPush(r0);
   }
 
   Variable* arguments = scope()->arguments();
   Variable* shadow = scope()->arguments_shadow();
   ASSERT(arguments != NULL && arguments->AsSlot() != NULL);
-  ASSERT(shadow != NULL && shadow->AsSlot() != NULL);
+  ASSERT(shadow != NULL && shadow->AsSlot() != NULL ||

[Kevin Millikin (Chromium), 2011/03/07 11:46:48]

Parens around the && please.

[Martin Maly, 2011/03/07 19:09:40]

Done.

+         scope()->is_strict_mode());
+
   JumpTarget done;
   if (mode == LAZY_ARGUMENTS_ALLOCATION && !initial) {
     // We have to skip storing into the arguments slot if it has
     // already been written to. This can happen if the a function
     // has a local variable named 'arguments'.
     LoadFromSlot(scope()->arguments()->AsSlot(), NOT_INSIDE_TYPEOF);
     Register arguments = frame_->PopToRegister();
     __ LoadRoot(ip, Heap::kArgumentsMarkerRootIndex);
     __ cmp(arguments, ip);
     done.Branch(ne);
   }
   StoreToSlot(arguments->AsSlot(), NOT_CONST_INIT);
   if (mode == LAZY_ARGUMENTS_ALLOCATION) done.Bind();
-  StoreToSlot(shadow->AsSlot(), NOT_CONST_INIT);
+  if (shadow != NULL) {
+    StoreToSlot(shadow->AsSlot(), NOT_CONST_INIT);
+  }
 }
 
 
 void CodeGenerator::LoadTypeofExpression(Expression* expr) {
   // Special handling of identifiers as subexpressions of typeof.
   Variable* variable = expr->AsVariableProxy()->AsVariable();
   if (variable != NULL && !variable->is_this() && variable->is_global()) {
     // For a global variable we build the property reference
     // <global>.<variable> and perform a (regular non-contextual) property
     // load to make sure we do not get reference errors.
@@ skipping 6754 matching lines @@
                BinaryOpIC::GetName(runtime_operands_type_));
   return name_;
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM