Implement sloppy-mode block-defined functions (Annex B 3.3)

src/ast.h

Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index 0486c3ee3f4f19a17f021857f6f2344ce27a447c..48362b7c5325e75de4ee6c865527789161a6148c 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -44,23 +44,24 @@ namespace internal {
   V(ImportDeclaration)           \
   V(ExportDeclaration)
 
-#define STATEMENT_NODE_LIST(V)                  \
-  V(Block)                                      \
-  V(ExpressionStatement)                        \
-  V(EmptyStatement)                             \
-  V(IfStatement)                                \
-  V(ContinueStatement)                          \
-  V(BreakStatement)                             \
-  V(ReturnStatement)                            \
-  V(WithStatement)                              \
-  V(SwitchStatement)                            \
-  V(DoWhileStatement)                           \
-  V(WhileStatement)                             \
-  V(ForStatement)                               \
-  V(ForInStatement)                             \
-  V(ForOfStatement)                             \
-  V(TryCatchStatement)                          \
-  V(TryFinallyStatement)                        \
+#define STATEMENT_NODE_LIST(V) \
+  V(Block)                     \
+  V(ExpressionStatement)       \
+  V(EmptyStatement)            \
+  V(DelegateStatement)         \
+  V(IfStatement)               \
+  V(ContinueStatement)         \
+  V(BreakStatement)            \
+  V(ReturnStatement)           \
+  V(WithStatement)             \
+  V(SwitchStatement)           \
+  V(DoWhileStatement)          \
+  V(WhileStatement)            \
+  V(ForStatement)              \
+  V(ForInStatement)            \
+  V(ForOfStatement)            \
+  V(TryCatchStatement)         \
+  V(TryFinallyStatement)       \
   V(DebuggerStatement)
 
 #define EXPRESSION_NODE_LIST(V) \
@@ -1268,6 +1269,29 @@ class EmptyStatement final : public Statement {
 };
 
 
+class DelegateStatement final : public Statement {
+  // Delegates to another statement, which may be overwritten.

[adamk, 2015/09/11 15:42:56]

Nit: class comments should go right above the declaration.

[Dan Ehrenberg, 2015/09/17 17:44:09]

Done

+  // This was introduced to implement ES2015 Annex B3.3 for conditionally making
+  // sloppy-mode block-scoped functions have a var binding, which is changed
+  // from one statement to another during parsing.
+ public:
+  DECLARE_NODE_TYPE(DelegateStatement)
+
+  Statement* statement() { return statement_; }

[adamk, 2015/09/11 15:42:56]

Make this a const method

[Dan Ehrenberg, 2015/09/17 17:44:09]

Done

+  void set_statement(Statement* statement) { statement_ = statement; }
+  Scope* scope() { return scope_; }

[adamk, 2015/09/11 15:42:56]

ditto: const please

[Dan Ehrenberg, 2015/09/17 17:44:09]

Done

+
+ protected:

[adamk, 2015/09/11 15:42:56]

I realize the use of "protected" here matches some other cases, but it makes no
sense to me, since this is a "final" class. Can this just be private?

[Dan Ehrenberg, 2015/09/17 17:44:09]

Done

+  explicit DelegateStatement(Zone* zone, int pos, Statement* statement,

[adamk, 2015/09/11 15:42:56]

No need for "explicit" here.

[Dan Ehrenberg, 2015/09/17 17:44:09]

Done

+                             Scope* scope)
+      : Statement(zone, pos), statement_(statement), scope_(scope) {}

[adamk, 2015/09/11 15:42:56]

Could you just pass RelocInfo::kNoPosition to the base class here and avoid
accepting a |pos| argument? I can't imagine a use-case for a DelegateStatement
that actually has a position.

[Dan Ehrenberg, 2015/09/17 17:44:09]

Done

+
+ private:
+  Statement* statement_;
+  Scope* scope_;
+};
+
+
 class Literal final : public Expression {
  public:
   DECLARE_NODE_TYPE(Literal)
@@ -3404,6 +3428,12 @@ class AstNodeFactory final BASE_EMBEDDED {
     return new (local_zone_) EmptyStatement(local_zone_, pos);
   }
 
+  DelegateStatement* NewDelegateStatement(int pos, Statement* statement,
+                                          Scope* scope) {
+    return new (local_zone_)
+        DelegateStatement(local_zone_, pos, statement, scope);
+  }
+
   CaseClause* NewCaseClause(
       Expression* label, ZoneList<Statement*>* statements, int pos) {
     return new (local_zone_) CaseClause(local_zone_, label, statements, pos);