Merge up to 8597 to experimental/gc from the bleeding edge.

src/scopes.h

Index: src/scopes.h
===================================================================
--- src/scopes.h	(revision 8618)
+++ src/scopes.h	(working copy)
@@ -1,4 +1,4 @@
-// Copyright 2010 the V8 project authors. All rights reserved.
+// Copyright 2011 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:
@@ -90,20 +90,14 @@
   // Construction
 
   enum Type {
-    EVAL_SCOPE,     // the top-level scope for an 'eval' source
-    FUNCTION_SCOPE,  // the top-level scope for a function
-    GLOBAL_SCOPE    // the top-level scope for a program or a top-level eval
+    EVAL_SCOPE,      // The top-level scope for an eval source.
+    FUNCTION_SCOPE,  // The top-level scope for a function.
+    GLOBAL_SCOPE,    // The top-level scope for a program or a top-level eval.
+    CATCH_SCOPE      // The scope introduced by catch.
   };
 
-  enum LocalType {
-    PARAMETER,
-    VAR_OR_CONST
-  };
-
   Scope(Scope* outer_scope, Type type);
 
-  virtual ~Scope() { }
-
   // Compute top scope and allocate variables. For lazy compilation the top
   // scope only contains the single lazily compiled function, so this
   // doesn't re-allocate variables repeatedly.
@@ -115,33 +109,31 @@
   // The scope name is only used for printing/debugging.
   void SetScopeName(Handle<String> scope_name) { scope_name_ = scope_name; }
 
-  virtual void Initialize(bool inside_with);
+  void Initialize(bool inside_with);
 
-  // Called just before leaving a scope.
-  virtual void Leave() {
-    // No cleanup or fixup necessary.
-  }
-
   // ---------------------------------------------------------------------------
   // Declarations
 
   // Lookup a variable in this scope. Returns the variable or NULL if not found.
-  virtual Variable* LocalLookup(Handle<String> name);
+  Variable* LocalLookup(Handle<String> name);
 
   // Lookup a variable in this scope or outer scopes.
   // Returns the variable or NULL if not found.
-  virtual Variable* Lookup(Handle<String> name);
+  Variable* Lookup(Handle<String> name);
 
   // Declare the function variable for a function literal. This variable
   // is in an intermediate scope between this function scope and the the
   // outer scope. Only possible for function scopes; at most one variable.
   Variable* DeclareFunctionVar(Handle<String> name);
 
+  // Declare a parameter in this scope.  When there are duplicated
+  // parameters the rightmost one 'wins'.  However, the implementation
+  // expects all parameters to be declared and from left to right.
+  void DeclareParameter(Handle<String> name);
+
   // Declare a local variable in this scope. If the variable has been
   // declared before, the previously declared variable is returned.
-  virtual Variable* DeclareLocal(Handle<String> name,
-                                 Variable::Mode mode,
-                                 LocalType type);
+  Variable* DeclareLocal(Handle<String> name, Variable::Mode mode);
 
   // Declare an implicit global variable in this scope which must be a
   // global scope.  The variable was introduced (possibly from an inner
@@ -149,16 +141,10 @@
   // with statements or eval calls.
   Variable* DeclareGlobal(Handle<String> name);
 
-  // Add a parameter to the parameter list. The parameter must have been
-  // declared via Declare. The same parameter may occur more than once in
-  // the parameter list; they must be added in source order, from left to
-  // right.
-  void AddParameter(Variable* var);
-
   // Create a new unresolved variable.
-  virtual VariableProxy* NewUnresolved(Handle<String> name,
-                                       bool inside_with,
-                                       int position = RelocInfo::kNoPosition);
+  VariableProxy* NewUnresolved(Handle<String> name,
+                               bool inside_with,
+                               int position = RelocInfo::kNoPosition);
 
   // Remove a unresolved variable. During parsing, an unresolved variable
   // may have been added optimistically, but then only the variable name
@@ -172,7 +158,7 @@
   // for printing and cannot be used to find the variable.  In particular,
   // the only way to get hold of the temporary is by keeping the Variable*
   // around.
-  virtual Variable* NewTemporary(Handle<String> name);
+  Variable* NewTemporary(Handle<String> name);
 
   // Adds the specific declaration node to the list of declarations in
   // this scope. The declarations are processed as part of entering
@@ -217,6 +203,7 @@
   bool is_eval_scope() const { return type_ == EVAL_SCOPE; }
   bool is_function_scope() const { return type_ == FUNCTION_SCOPE; }
   bool is_global_scope() const { return type_ == GLOBAL_SCOPE; }
+  bool is_catch_scope() const { return type_ == CATCH_SCOPE; }
   bool is_strict_mode() const { return strict_mode_; }
   bool is_strict_mode_eval_scope() const {
     return is_eval_scope() && is_strict_mode();
@@ -240,13 +227,8 @@
   // ---------------------------------------------------------------------------
   // Accessors.
 
-  // A new variable proxy corresponding to the (function) receiver.
-  VariableProxy* receiver() const {
-    VariableProxy* proxy =
-        new VariableProxy(FACTORY->this_symbol(), true, false);
-    proxy->BindTo(receiver_);
-    return proxy;
-  }
+  // The variable corresponding the 'this' value.
+  Variable* receiver() { return receiver_; }
 
   // The variable holding the function literal for named function
   // literals, or NULL.
@@ -266,18 +248,12 @@
   int num_parameters() const { return params_.length(); }
 
   // The local variable 'arguments' if we need to allocate it; NULL otherwise.
-  // If arguments() exist, arguments_shadow() exists, too.
   Variable* arguments() const { return arguments_; }
 
-  // The '.arguments' shadow variable if we need to allocate it; NULL otherwise.
-  // If arguments_shadow() exist, arguments() exists, too.
-  Variable* arguments_shadow() const { return arguments_shadow_; }
-
   // Declarations list.
   ZoneList<Declaration*>* declarations() { return &decls_; }
 
 
-
   // ---------------------------------------------------------------------------
   // Variable allocation.
 
@@ -309,11 +285,15 @@
   bool AllowsLazyCompilation() const;
 
   // True if the outer context of this scope is always the global context.
-  virtual bool HasTrivialOuterContext() const;
+  bool HasTrivialOuterContext() const;
 
   // The number of contexts between this and scope; zero if this == scope.
   int ContextChainLength(Scope* scope);
 
+  // Find the first function, global, or eval scope.  This is the scope
+  // where var declarations will be hoisted to in the implementation.
+  Scope* DeclarationScope();
+
   // ---------------------------------------------------------------------------
   // Strict mode support.
   bool IsDeclared(Handle<String> name) {
@@ -371,8 +351,6 @@
   Variable* function_;
   // Convenience variable; function scopes only.
   Variable* arguments_;
-  // Convenience variable; function scopes only.
-  Variable* arguments_shadow_;
 
   // Illegal redeclaration.
   Expression* illegal_redecl_;
@@ -390,6 +368,10 @@
   bool outer_scope_is_eval_scope_;
   bool force_eager_compilation_;
 
+  // True if it doesn't need scope resolution (e.g., if the scope was
+  // constructed based on a serialized scope info or a catch context).
+  bool already_resolved_;
+
   // Computed as variables are declared.
   int num_var_or_const_;
 
@@ -399,7 +381,7 @@
 
   // Serialized scopes support.
   Handle<SerializedScopeInfo> scope_info_;
-  bool resolved() { return !scope_info_.is_null(); }
+  bool already_resolved() { return already_resolved_; }
 
   // Create a non-local variable with a given name.
   // These variables are looked up dynamically at runtime.
@@ -435,8 +417,12 @@
   void AllocateVariablesRecursively();
 
  private:
+  // Construct a function scope based on the scope info.
   Scope(Scope* inner_scope, Handle<SerializedScopeInfo> scope_info);
 
+  // Construct a catch scope with a binding for the name.
+  Scope(Scope* inner_scope, Handle<String> catch_variable_name);
+
   void AddInnerScope(Scope* inner_scope) {
     if (inner_scope != NULL) {
       inner_scopes_.Add(inner_scope);
@@ -449,59 +435,6 @@
                    Handle<SerializedScopeInfo> scope_info);
 };
 
-
-// Scope used during pre-parsing.
-class DummyScope : public Scope {
- public:
-  DummyScope()
-      : Scope(GLOBAL_SCOPE),
-        nesting_level_(1),  // Allows us to Leave the initial scope.
-        inside_with_level_(kNotInsideWith) {
-    outer_scope_ = this;
-    scope_inside_with_ = false;
-  }
-
-  virtual void Initialize(bool inside_with) {
-    nesting_level_++;
-    if (inside_with && inside_with_level_ == kNotInsideWith) {
-      inside_with_level_ = nesting_level_;
-    }
-    ASSERT(inside_with_level_ <= nesting_level_);
-  }
-
-  virtual void Leave() {
-    nesting_level_--;
-    ASSERT(nesting_level_ >= 0);
-    if (nesting_level_ < inside_with_level_) {
-      inside_with_level_ = kNotInsideWith;
-    }
-    ASSERT(inside_with_level_ <= nesting_level_);
-  }
-
-  virtual Variable* Lookup(Handle<String> name)  { return NULL; }
-
-  virtual VariableProxy* NewUnresolved(Handle<String> name,
-                                       bool inside_with,
-                                       int position = RelocInfo::kNoPosition) {
-    return NULL;
-  }
-
-  virtual Variable* NewTemporary(Handle<String> name)  { return NULL; }
-
-  virtual bool HasTrivialOuterContext() const {
-    return (nesting_level_ == 0 || inside_with_level_ <= 0);
-  }
-
- private:
-  static const int kNotInsideWith = -1;
-  // Number of surrounding scopes of the current scope.
-  int nesting_level_;
-  // Nesting level of outermost scope that is contained in a with statement,
-  // or kNotInsideWith if there are no with's around the current scope.
-  int inside_with_level_;
-};
-
-
 } }  // namespace v8::internal
 
 #endif  // V8_SCOPES_H_