Fix FuncNameInferrer usage in ParseAssignmentExpression

src/parsing/parser.cc

 // 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.
 
 #include "src/parsing/parser.h"
 
 #include "src/api.h"
 #include "src/ast/ast.h"
 #include "src/ast/ast-expression-visitor.h"
 #include "src/ast/ast-literal-reindexer.h"
@@ skipping 2235 matching lines @@
   // GeneratorDeclaration ::
   //   'function' '*' Identifier '(' FormalParameterListopt ')'
   //      '{' FunctionBody '}'
   Expect(Token::FUNCTION, CHECK_OK);
   int pos = position();
   bool is_generator = Check(Token::MUL);
   bool is_strict_reserved = false;
   const AstRawString* name = ParseIdentifierOrStrictReservedWord(
       &is_strict_reserved, CHECK_OK);
 
-  if (fni_ != NULL) {
-    fni_->Enter();
-    fni_->PushEnclosingName(name);
-  }
+  FuncNameInferrer::State fni_state(fni_);
+  if (fni_ != NULL) fni_->PushEnclosingName(name);
   FunctionLiteral* fun = ParseFunctionLiteral(
       name, scanner()->location(),
       is_strict_reserved ? kFunctionNameIsStrictReserved
                          : kFunctionNameValidityUnknown,
       is_generator ? FunctionKind::kGeneratorFunction
                    : FunctionKind::kNormalFunction,
       pos, FunctionLiteral::DECLARATION, FunctionLiteral::NORMAL_ARITY,
       language_mode(), CHECK_OK);
-  if (fni_ != NULL) fni_->Leave();
 
   // Even if we're not at the top-level of the global or a function
   // scope, we treat it as such and introduce the function with its
   // initial value upon entering the corresponding scope.
   // In ES6, a function behaves as a lexical binding, except in
   // a script scope, or the initial scope of eval or another function.
   VariableMode mode =
       is_strong(language_mode())
           ? CONST
           : (is_strict(language_mode()) || allow_harmony_sloppy_function()) &&
@@ skipping 209 matching lines @@
   }
 
   parsing_result->descriptor.scope = scope_;
   parsing_result->descriptor.hoist_scope = nullptr;
 
 
   bool first_declaration = true;
   int bindings_start = peek_position();
   bool is_for_iteration_variable;
   do {
-    if (fni_ != NULL) fni_->Enter();
+    FuncNameInferrer::State fni_state(fni_);
 
     // Parse name.
     if (!first_declaration) Consume(Token::COMMA);
 
     Expression* pattern;
     int decl_pos = peek_position();
     {
       ExpressionClassifier pattern_classifier;
       Token::Value next = peek();
       pattern = ParsePrimaryExpression(&pattern_classifier, ok);
@@ skipping 69 matching lines @@
       }
       // End position of the initializer is after the variable.
       initializer_position = position();
     }
 
     // Make sure that 'const x' and 'let x' initialize 'x' to undefined.
     if (value == NULL && parsing_result->descriptor.needs_init) {
       value = GetLiteralUndefined(position());
     }
 
-    if (single_name && fni_ != NULL) fni_->Leave();

[adamk, 2015/12/10 01:56:53]

Pretty sure this was a bug before.

[Dan Ehrenberg, 2015/12/10 18:22:41]

Awesome!

     parsing_result->declarations.Add(DeclarationParsingResult::Declaration(
         pattern, initializer_position, value));
     first_declaration = false;
   } while (peek() == Token::COMMA);
 
   parsing_result->bindings_loc =
       Scanner::Location(bindings_start, scanner()->location().end_pos);
 }
 
 
@@ skipping 2337 matching lines @@
   ClassLiteralChecker checker(this);
   ZoneList<ObjectLiteral::Property*>* properties = NewPropertyList(4, zone());
   FunctionLiteral* constructor = NULL;
   bool has_seen_constructor = false;
 
   Expect(Token::LBRACE, CHECK_OK);
 
   const bool has_extends = extends != nullptr;
   while (peek() != Token::RBRACE) {
     if (Check(Token::SEMICOLON)) continue;
-    if (fni_ != NULL) fni_->Enter();
+    FuncNameInferrer::State fni_state(fni_);
     const bool in_class = true;
     const bool is_static = false;
     bool is_computed_name = false;  // Classes do not care about computed
                                     // property names here.
     ExpressionClassifier classifier;
     ObjectLiteral::Property* property = ParsePropertyDefinition(
         &checker, in_class, has_extends, is_static, &is_computed_name,
         &has_seen_constructor, &classifier, CHECK_OK);
     ValidateExpression(&classifier, CHECK_OK);
 
     if (has_seen_constructor && constructor == NULL) {
       constructor = GetPropertyValue(property)->AsFunctionLiteral();
       DCHECK_NOT_NULL(constructor);
     } else {
       properties->Add(property, zone());
     }
 
-    if (fni_ != NULL) {
-      fni_->Infer();
-      fni_->Leave();
-    }
+    if (fni_ != NULL) fni_->Infer();
   }
 
   Expect(Token::RBRACE, CHECK_OK);
   int end_pos = scanner()->location().end_pos;
 
   if (constructor == NULL) {
     constructor = DefaultConstructor(extends != NULL, block_scope, pos, end_pos,
                                      block_scope->language_mode());
   }
 
@@ skipping 1563 matching lines @@
 
 void ParserTraits::QueueDestructuringAssignmentForRewriting(Expression* expr) {
   DCHECK(expr->IsRewritableAssignmentExpression());
   parser_->function_state_->AddDestructuringAssignment(
       Parser::DestructuringAssignment(expr, parser_->scope_));
 }
 
 
 }  // namespace internal
 }  // namespace v8