Merge 6800:7180 from the bleeding edge branch to the experimental/gc branch.

src/scopes.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 130 matching lines @@
 
 
 Scope::Scope(Scope* inner_scope, SerializedScopeInfo* scope_info)
   : inner_scopes_(4),
     variables_(),
     temps_(4),
     params_(4),
     unresolved_(16),
     decls_(4) {
   ASSERT(scope_info != NULL);
-  SetDefaults(FUNCTION_SCOPE, inner_scope->outer_scope(), scope_info);
+  SetDefaults(FUNCTION_SCOPE, NULL, scope_info);
   ASSERT(resolved());
-  InsertAfterScope(inner_scope);
   if (scope_info->HasHeapAllocatedLocals()) {
     num_heap_slots_ = scope_info_->NumberOfContextSlots();
   }
 
+  AddInnerScope(inner_scope);
+
   // This scope's arguments shadow (if present) is context-allocated if an inner
   // scope accesses this one's parameters.  Allocate the arguments_shadow_
   // variable if necessary.
   Variable::Mode mode;
   int arguments_shadow_index =
       scope_info_->ContextSlotIndex(Heap::arguments_shadow_symbol(), &mode);
   if (arguments_shadow_index >= 0) {
     ASSERT(mode == Variable::INTERNAL);
     arguments_shadow_ = new Variable(this,
                                      Factory::arguments_shadow_symbol(),
                                      Variable::INTERNAL,
                                      true,
                                      Variable::ARGUMENTS);
     arguments_shadow_->set_rewrite(
         new Slot(arguments_shadow_, Slot::CONTEXT, arguments_shadow_index));
     arguments_shadow_->set_is_used(true);
   }
 }
 
 
+Scope* Scope::DeserializeScopeChain(CompilationInfo* info,
+                                    Scope* global_scope) {
+  ASSERT(!info->closure().is_null());
+  // If we have a serialized scope info, reuse it.
+  Scope* innermost_scope = NULL;
+  Scope* scope = NULL;
+
+  SerializedScopeInfo* scope_info = info->closure()->shared()->scope_info();
+  if (scope_info != SerializedScopeInfo::Empty()) {
+    JSFunction* current = *info->closure();
+    do {
+      current = current->context()->closure();
+      SerializedScopeInfo* scope_info = current->shared()->scope_info();
+      if (scope_info != SerializedScopeInfo::Empty()) {
+        scope = new Scope(scope, scope_info);
+        if (innermost_scope == NULL) innermost_scope = scope;
+      } else {
+        ASSERT(current->context()->IsGlobalContext());
+      }
+    } while (!current->context()->IsGlobalContext());
+  }
+
+  global_scope->AddInnerScope(scope);
+  if (innermost_scope == NULL) innermost_scope = global_scope;
+
+  return innermost_scope;
+}
+
 
 bool Scope::Analyze(CompilationInfo* info) {
   ASSERT(info->function() != NULL);
   Scope* top = info->function()->scope();
 
-  // If we have a serialized scope info, reuse it.
-  if (!info->closure().is_null()) {
-    SerializedScopeInfo* scope_info = info->closure()->shared()->scope_info();
-    if (scope_info != SerializedScopeInfo::Empty()) {
-      Scope* scope = top;
-      JSFunction* current = *info->closure();
-      do {
-        current = current->context()->closure();
-        SerializedScopeInfo* scope_info = current->shared()->scope_info();
-        if (scope_info != SerializedScopeInfo::Empty()) {
-          scope = new Scope(scope, scope_info);
-        } else {
-          ASSERT(current->context()->IsGlobalContext());
-        }
-      } while (!current->context()->IsGlobalContext());
-    }
-  }
-
   while (top->outer_scope() != NULL) top = top->outer_scope();
   top->AllocateVariables(info->calling_context());
 
 #ifdef DEBUG
   if (Bootstrapper::IsActive()
           ? FLAG_print_builtin_scopes
           : FLAG_print_scopes) {
     info->function()->scope()->Print();
   }
 #endif
@@ skipping 660 matching lines @@
 
 void Scope::AllocateHeapSlot(Variable* var) {
   var->set_rewrite(new Slot(var, Slot::CONTEXT, num_heap_slots_++));
 }
 
 
 void Scope::AllocateParameterLocals() {
   ASSERT(is_function_scope());
   Variable* arguments = LocalLookup(Factory::arguments_symbol());
   ASSERT(arguments != NULL);  // functions have 'arguments' declared implicitly
+
+  // Parameters are rewritten to arguments[i] if 'arguments' is used in
+  // a non-strict mode function. Strict mode code doesn't alias arguments.
+  bool rewrite_parameters = false;
+
   if (MustAllocate(arguments) && !HasArgumentsParameter()) {
     // 'arguments' is used. Unless there is also a parameter called
     // 'arguments', we must be conservative and access all parameters via
     // the arguments object: The i'th parameter is rewritten into
     // '.arguments[i]' (*). If we have a parameter named 'arguments', a
     // (new) value is always assigned to it via the function
     // invocation. Then 'arguments' denotes that specific parameter value
     // and cannot be used to access the parameters, which is why we don't
     // need to rewrite in that case.
     //
@@ skipping 11 matching lines @@
     // allocated. All parameters are rewritten into property accesses via
     // the '.arguments' variable. Thus, any changes to properties of
     // 'arguments' are reflected in the variables and vice versa. If the
     // 'arguments' variable is changed, '.arguments' still points to the
     // correct arguments object and the rewrites still work.
 
     // We are using 'arguments'. Tell the code generator that is needs to
     // allocate the arguments object by setting 'arguments_'.
     arguments_ = arguments;
 
+    // In strict mode 'arguments' does not alias formal parameters.
+    // Therefore in strict mode we allocate parameters as if 'arguments'
+    // were not used.
+    rewrite_parameters = !is_strict_mode();
+  }
+
+  if (rewrite_parameters) {
     // We also need the '.arguments' shadow variable. Declare it and create
     // and bind the corresponding proxy. It's ok to declare it only now
     // because it's a local variable that is allocated after the parameters
     // have been allocated.
     //
     // Note: This is "almost" at temporary variable but we cannot use
     // NewTemporary() because the mode needs to be INTERNAL since this
     // variable may be allocated in the heap-allocated context (temporaries
     // are never allocated in the context).
     arguments_shadow_ = new Variable(this,
@@ skipping 132 matching lines @@
   if (num_heap_slots_ == Context::MIN_CONTEXT_SLOTS &&
       !must_have_local_context) {
     num_heap_slots_ = 0;
   }
 
   // Allocation done.
   ASSERT(num_heap_slots_ == 0 || num_heap_slots_ >= Context::MIN_CONTEXT_SLOTS);
 }
 
 } }  // namespace v8::internal