[inspector] removed call break location from for-of loop

src/parsing/parser-base.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_PARSER_BASE_H
 #define V8_PARSING_PARSER_BASE_H
 
 #include "src/ast/ast.h"
 #include "src/ast/scopes.h"
 #include "src/bailout-reason.h"
@@ skipping 5617 matching lines @@
                             ForEachStatement::VisitModeString(for_info->mode));
     *ok = false;
     return impl()->NullStatement();
   }
 
   BlockT init_block = impl()->RewriteForVarInLegacy(*for_info);
 
   auto loop = factory()->NewForEachStatement(for_info->mode, labels, stmt_pos);
   typename Types::Target target(this, loop);
 
-  int each_keyword_pos = scanner()->location().beg_pos;
-
   ExpressionT enumerable = impl()->EmptyExpression();
   if (for_info->mode == ForEachStatement::ITERATE) {
     ExpressionClassifier classifier(this);
     enumerable = ParseAssignmentExpression(true, CHECK_OK);
     impl()->RewriteNonPattern(CHECK_OK);
   } else {
     enumerable = ParseExpression(true, CHECK_OK);
   }
 
   Expect(Token::RPAREN, CHECK_OK);
 
   StatementT final_loop = impl()->NullStatement();
   {
     ReturnExprScope no_tail_calls(function_state_,
                                   ReturnExprContext::kInsideForInOfBody);
     BlockState block_state(zone(), &scope_);
     scope()->set_start_position(scanner()->location().beg_pos);
 
     StatementT body = ParseStatement(nullptr, CHECK_OK);
 
     BlockT body_block = impl()->NullBlock();
     ExpressionT each_variable = impl()->EmptyExpression();
     impl()->DesugarBindingInForEachStatement(for_info, &body_block,
                                              &each_variable, CHECK_OK);
     body_block->statements()->Add(body, zone());
-    final_loop = impl()->InitializeForEachStatement(
-        loop, each_variable, enumerable, body_block, each_keyword_pos);
+    final_loop = impl()->InitializeForEachStatement(loop, each_variable,

[jgruber, 2017/05/23 12:33:57]

I'm trying to understand the logic change this CL implements; so here we will
create a break location since each_variable's location is initialized by
DesugarBindingInForEachStatement, and break locations depend on whether source
locations are set.

+                                                    enumerable, body_block);
 
     scope()->set_end_position(scanner()->location().end_pos);
     body_block->set_scope(scope()->FinalizeBlockScope());
   }
 
   init_block = impl()->CreateForEachStatementTDZ(init_block, *for_info, ok);
 
   scope()->set_end_position(scanner()->location().end_pos);
   Scope* for_scope = scope()->FinalizeBlockScope();
   // Parsed for-in loop w/ variable declarations.
@@ skipping 16 matching lines @@
   // Initializer is reference followed by in/of.
   if (!expression->IsArrayLiteral() && !expression->IsObjectLiteral()) {
     expression = impl()->CheckAndRewriteReferenceExpression(
         expression, lhs_beg_pos, lhs_end_pos, MessageTemplate::kInvalidLhsInFor,
         kSyntaxError, CHECK_OK);
   }
 
   auto loop = factory()->NewForEachStatement(for_info->mode, labels, stmt_pos);
   typename Types::Target target(this, loop);
 
-  int each_keyword_pos = scanner()->location().beg_pos;
-
   ExpressionT enumerable = impl()->EmptyExpression();
   if (for_info->mode == ForEachStatement::ITERATE) {
     ExpressionClassifier classifier(this);
     enumerable = ParseAssignmentExpression(true, CHECK_OK);
     impl()->RewriteNonPattern(CHECK_OK);
   } else {
     enumerable = ParseExpression(true, CHECK_OK);
   }
 
   Expect(Token::RPAREN, CHECK_OK);
   Scope* for_scope = scope();
 
   {
     ReturnExprScope no_tail_calls(function_state_,
                                   ReturnExprContext::kInsideForInOfBody);
     BlockState block_state(zone(), &scope_);
     scope()->set_start_position(scanner()->location().beg_pos);
 
     StatementT body = ParseStatement(nullptr, CHECK_OK);
     scope()->set_end_position(scanner()->location().end_pos);
-    StatementT final_loop = impl()->InitializeForEachStatement(
-        loop, expression, enumerable, body, each_keyword_pos);
+    StatementT final_loop =
+        impl()->InitializeForEachStatement(loop, expression, enumerable, body);

[jgruber, 2017/05/23 12:33:57]

While here it all depends on whether expression's location has been initialized.
That's pretty subtle - I still don't understand if there's a logic change here
or this is a pure refactoring.

Maybe it'd help if we made it more explicit, e.g. by keeping the position
argument in InitializeForEachStatement. WDYT?

[kozy, 2017/05/23 12:56:28]

It's not just refactoring, location for for..of loops is moved from before "of"
to before each variable / expression and I'd like to use this expression
location as break location since it looks more natural.

 
     for_scope = for_scope->FinalizeBlockScope();
     USE(for_scope);
     DCHECK_NULL(for_scope);
     Scope* block_scope = scope()->FinalizeBlockScope();
     USE(block_scope);
     DCHECK_NULL(block_scope);
     return final_loop;
   }
 }
@@ skipping 281 matching lines @@
 }
 
 #undef CHECK_OK
 #undef CHECK_OK_CUSTOM
 #undef CHECK_OK_VOID
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_BASE_H