[parser] Skipping inner funcs: produce the same scopes / variables for loops.

src/parsing/preparser.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_PARSING_PREPARSER_H
 #define V8_PARSING_PREPARSER_H
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/parsing/parser-base.h"
@@ skipping 1302 matching lines @@
 
   V8_INLINE PreParserStatement RewriteForVarInLegacy(const ForInfo& for_info) {
     return PreParserStatement::Null();
   }
 
   V8_INLINE void DesugarBindingInForEachStatement(
       ForInfo* for_info, PreParserStatement* body_block,
       PreParserExpression* each_variable, bool* ok) {
     if (track_unresolved_variables_) {
       DCHECK(for_info->parsing_result.declarations.length() == 1);
+      bool is_for_var_of =
+          for_info->mode == ForEachStatement::ITERATE &&
+          for_info->parsing_result.descriptor.mode == VariableMode::VAR;
+
       DeclareAndInitializeVariables(
           PreParserStatement::Default(), &for_info->parsing_result.descriptor,
-          &for_info->parsing_result.declarations[0], nullptr, ok);
+          &for_info->parsing_result.declarations[0],
+          (IsLexicalVariableMode(for_info->parsing_result.descriptor.mode) ||

[vogelheim, 2017/02/06 10:02:11]

super nitpick: Maybe hoist this expression into an additional bool, too.

bool requires_variable_declaration = is_for_var_of || IsLexicalVa...;
(... not sure that's a good name...)

[marja, 2017/02/06 10:11:53]

added collect_names = ... here and in the corresponding place in parser.cc

+           is_for_var_of)
+              ? &for_info->bound_names
+              : nullptr,
+          ok);
     }
   }
 
   V8_INLINE PreParserStatement CreateForEachStatementTDZ(
       PreParserStatement init_block, const ForInfo& for_info, bool* ok) {
+    if (track_unresolved_variables_) {
+      if (IsLexicalVariableMode(for_info.parsing_result.descriptor.mode)) {
+        for (auto name : for_info.bound_names) {
+          scope()->DeclareVariableName(name, LET);
+        }
+        return PreParserStatement::Default();
+      }
+    }
     return init_block;
   }
 
   V8_INLINE StatementT DesugarLexicalBindingsInForStatement(
       PreParserStatement loop, PreParserStatement init,
       PreParserExpression cond, PreParserStatement next,
       PreParserStatement body, Scope* inner_scope, const ForInfo& for_info,
       bool* ok) {
     // See Parser::DesugarLexicalBindingsInForStatement.
-    for (int i = 0; i < for_info.bound_names.length(); i++) {
-      inner_scope->DeclareVariableName(for_info.bound_names[i],
-                                       for_info.parsing_result.descriptor.mode);
+    if (track_unresolved_variables_) {
+      for (auto name : for_info.bound_names) {
+        inner_scope->DeclareVariableName(
+            name, for_info.parsing_result.descriptor.mode);
+      }
     }
     return loop;
   }
 
   V8_INLINE PreParserStatement BuildParameterInitializationBlock(
       const PreParserFormalParameters& parameters, bool* ok) {
     return PreParserStatement::Default();
   }
 
   V8_INLINE PreParserStatement
@@ skipping 310 matching lines @@
     function_state_->NextMaterializedLiteralIndex();
     function_state_->NextMaterializedLiteralIndex();
   }
   return EmptyExpression();
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PREPARSER_H