ParameterInitializerRewriter must maintain temporary variable order

src/ast/scopes.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_AST_SCOPES_H_
 #define V8_AST_SCOPES_H_
 
 #include "src/ast/ast.h"
 #include "src/hashmap.h"
 #include "src/pending-compilation-error-handler.h"
@@ skipping 191 matching lines @@
 
   // Creates a new temporary variable in this scope's TemporaryScope.  The
   // name is only used 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.  The name should not clash with a legitimate variable
   // names.
   Variable* NewTemporary(const AstRawString* name);
 
   // Remove a temporary variable. This is for adjusting the scope of
   // temporaries used when desugaring parameter initializers.
-  bool RemoveTemporary(Variable* var);
+  // Returns the index at which it was found in this scope, or -1 if
+  // it was not found.
+  int RemoveTemporary(Variable* var);
 
   // Adds a temporary variable in this scope's TemporaryScope. This is for
   // adjusting the scope of temporaries used when desugaring parameter
   // initializers.
   void AddTemporary(Variable* var) { temps_.Add(var, zone()); }
 
   // Adds the specific declaration node to the list of declarations in
   // this scope. The declarations are processed as part of entering
   // the scope; see codegen.cc:ProcessDeclarations.
   void AddDeclaration(Declaration* declaration);
@@ skipping 375 matching lines @@
 
   // Debugging support.
   const AstRawString* scope_name_;
 
   // The variables declared in this scope:
   //
   // All user-declared variables (incl. parameters).  For script scopes
   // variables may be implicitly 'declared' by being used (possibly in
   // an inner scope) with no intervening with statements or eval calls.
   VariableMap variables_;
-  // Compiler-allocated (user-invisible) temporaries.
+  // Compiler-allocated (user-invisible) temporaries. Due to the implementation
+  // of RemoveTemporary(), may contain nulls, which must be skipped-over during
+  // allocation and printing.
   ZoneList<Variable*> temps_;
   // Parameter list in source order.
   ZoneList<Variable*> params_;
   // Variables that must be looked up dynamically.
   DynamicScopePart* dynamics_;
   // Unresolved variables referred to from this scope.
   ZoneList<VariableProxy*> unresolved_;
   // Declarations.
   ZoneList<Declaration*> decls_;
   // Convenience variable.
@@ skipping 191 matching lines @@
   AstValueFactory* ast_value_factory_;
   Zone* zone_;
 
   PendingCompilationErrorHandler pending_error_handler_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_SCOPES_H_