Clean up some messiness in Scopes.

src/arm/full-codegen-arm.cc

Index: src/arm/full-codegen-arm.cc
diff --git a/src/arm/full-codegen-arm.cc b/src/arm/full-codegen-arm.cc
index be78c09a96683b048315fa545fed42bb04a993de..9fc0c096bbb1f5c8941e3a8bb46874733c7aa6a4 100644
--- a/src/arm/full-codegen-arm.cc
+++ b/src/arm/full-codegen-arm.cc
@@ -100,7 +100,7 @@ void FullCodeGenerator::Generate(CompilationInfo* info) {
     // Copy any necessary parameters into the context.
     int num_parameters = scope()->num_parameters();
     for (int i = 0; i < num_parameters; i++) {
-      Slot* slot = scope()->parameter(i)->slot();
+      Slot* slot = scope()->parameter(i)->AsSlot();
       if (slot != NULL && slot->type() == Slot::CONTEXT) {
         int parameter_offset = StandardFrameConstants::kCallerSPOffset +
             (num_parameters - 1 - i) * kPointerSize;
@@ -118,7 +118,7 @@ void FullCodeGenerator::Generate(CompilationInfo* info) {
     }
   }
 
-  Variable* arguments = scope()->arguments()->AsVariable();
+  Variable* arguments = scope()->arguments();
   if (arguments != NULL) {
     // Function uses arguments object.
     Comment cmnt(masm_, "[ Allocate arguments object");
@@ -143,9 +143,8 @@ void FullCodeGenerator::Generate(CompilationInfo* info) {
     __ CallStub(&stub);
     // Duplicate the value; move-to-slot operation might clobber registers.
     __ mov(r3, r0);
-    Move(arguments->slot(), r0, r1, r2);
-    Slot* dot_arguments_slot =
-        scope()->arguments_shadow()->AsVariable()->slot();
+    Move(arguments->AsSlot(), r0, r1, r2);
+    Slot* dot_arguments_slot = scope()->arguments_shadow()->AsSlot();
     Move(dot_arguments_slot, r3, r1, r2);
   }
 
@@ -530,7 +529,7 @@ void FullCodeGenerator::EmitDeclaration(Variable* variable,
                                         FunctionLiteral* function) {
   Comment cmnt(masm_, "[ Declaration");
   ASSERT(variable != NULL);  // Must have been resolved.
-  Slot* slot = variable->slot();
+  Slot* slot = variable->AsSlot();
   Property* prop = variable->AsProperty();
 
   if (slot != NULL) {
@@ -924,7 +923,7 @@ void FullCodeGenerator::EmitDynamicLoadFromSlotFastCase(
     EmitLoadGlobalSlotCheckExtensions(slot, typeof_state, slow);
     __ jmp(done);
   } else if (slot->var()->mode() == Variable::DYNAMIC_LOCAL) {
-    Slot* potential_slot = slot->var()->local_if_not_shadowed()->slot();
+    Slot* potential_slot = slot->var()->local_if_not_shadowed()->AsSlot();
     Expression* rewrite = slot->var()->local_if_not_shadowed()->rewrite();
     if (potential_slot != NULL) {
       // Generate fast case for locals that rewrite to slots.
@@ -949,7 +948,7 @@ void FullCodeGenerator::EmitDynamicLoadFromSlotFastCase(
           // variables. Then load the argument from the arguments
           // object using keyed load.
           __ ldr(r1,
-                 ContextSlotOperandCheckExtensions(obj_proxy->var()->slot(),
+                 ContextSlotOperandCheckExtensions(obj_proxy->var()->AsSlot(),
                                                    slow));
           __ mov(r0, Operand(key_literal->handle()));
           Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize));
@@ -1027,7 +1026,7 @@ void FullCodeGenerator::EmitVariableLoad(Variable* var) {
   // Four cases: non-this global variables, lookup slots, all other
   // types of slots, and parameters that rewrite to explicit property
   // accesses on the arguments object.
-  Slot* slot = var->slot();
+  Slot* slot = var->AsSlot();
   Property* property = var->AsProperty();
 
   if (var->is_global() && !var->is_this()) {
@@ -1080,7 +1079,7 @@ void FullCodeGenerator::EmitVariableLoad(Variable* var) {
     // Assert that the object is in a slot.
     Variable* object_var = property->obj()->AsVariableProxy()->AsVariable();
     ASSERT_NOT_NULL(object_var);
-    Slot* object_slot = object_var->slot();
+    Slot* object_slot = object_var->AsSlot();
     ASSERT_NOT_NULL(object_slot);
 
     // Load the object.
@@ -1489,7 +1488,7 @@ void FullCodeGenerator::EmitVariableAssignment(Variable* var,
   // Left-hand sides that rewrite to explicit property accesses do not reach
   // here.
   ASSERT(var != NULL);
-  ASSERT(var->is_global() || var->slot() != NULL);
+  ASSERT(var->is_global() || var->AsSlot() != NULL);
 
   if (var->is_global()) {
     ASSERT(!var->is_this());
@@ -1505,7 +1504,7 @@ void FullCodeGenerator::EmitVariableAssignment(Variable* var,
     // Perform the assignment for non-const variables and for initialization
     // of const variables.  Const assignments are simply skipped.
     Label done;
-    Slot* slot = var->slot();
+    Slot* slot = var->AsSlot();
     switch (slot->type()) {
       case Slot::PARAMETER:
       case Slot::LOCAL:
@@ -1785,14 +1784,14 @@ void FullCodeGenerator::VisitCall(Call* expr) {
     __ ldr(r0, CodeGenerator::GlobalObject());
     __ push(r0);
     EmitCallWithIC(expr, var->name(), RelocInfo::CODE_TARGET_CONTEXT);
-  } else if (var != NULL && var->slot() != NULL &&
-             var->slot()->type() == Slot::LOOKUP) {
+  } else if (var != NULL && var->AsSlot() != NULL &&
+             var->AsSlot()->type() == Slot::LOOKUP) {
     // Call to a lookup slot (dynamically introduced variable).
     Label slow, done;
 
     // Generate code for loading from variables potentially shadowed
     // by eval-introduced variables.
-    EmitDynamicLoadFromSlotFastCase(var->slot(),
+    EmitDynamicLoadFromSlotFastCase(var->AsSlot(),
                                     NOT_INSIDE_TYPEOF,
                                     &slow,
                                     &done);
@@ -2782,8 +2781,8 @@ void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
         context()->Plug(true);
       } else if (var != NULL &&
                  !var->is_global() &&
-                 var->slot() != NULL &&
-                 var->slot()->type() != Slot::LOOKUP) {
+                 var->AsSlot() != NULL &&
+                 var->AsSlot()->type() != Slot::LOOKUP) {
         // Result of deleting non-global, non-dynamic variables is false.
         // The subexpression does not have side effects.
         context()->Plug(false);
@@ -3068,13 +3067,13 @@ void FullCodeGenerator::VisitForTypeofValue(Expression* expr) {
     EmitCallIC(ic, RelocInfo::CODE_TARGET);
     context()->Plug(r0);
   } else if (proxy != NULL &&
-             proxy->var()->slot() != NULL &&
-             proxy->var()->slot()->type() == Slot::LOOKUP) {
+             proxy->var()->AsSlot() != NULL &&
+             proxy->var()->AsSlot()->type() == Slot::LOOKUP) {
     Label done, slow;
 
     // Generate code for loading from variables potentially shadowed
     // by eval-introduced variables.
-    Slot* slot = proxy->var()->slot();
+    Slot* slot = proxy->var()->AsSlot();
     EmitDynamicLoadFromSlotFastCase(slot, INSIDE_TYPEOF, &slow, &done);
 
     __ bind(&slow);