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

src/parsing/preparser.h

Index: src/parsing/preparser.h
diff --git a/src/parsing/preparser.h b/src/parsing/preparser.h
index 0120c2c5dffaf33bb24982f1447b6baa2d2b4dc2..23b8c52ff416da37bee5123ce0731de07670588b 100644
--- a/src/parsing/preparser.h
+++ b/src/parsing/preparser.h
@@ -1320,14 +1320,31 @@ class PreParser : public ParserBase<PreParser> {
       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;
   }
 
@@ -1337,9 +1354,11 @@ class PreParser : public ParserBase<PreParser> {
       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;
   }