[parser] Refactor of Parse*Statement*, part 8

src/parsing/preparser.cc

 // Copyright 2011 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 <cmath>
 
 #include "src/allocation.h"
 #include "src/base/logging.h"
 #include "src/conversions-inl.h"
 #include "src/conversions.h"
@@ skipping 146 matching lines @@
       *ok = false;
       return Statement::Default();
     }
   }
   // PreParser is not able to parse "export default" yet (since PreParser is
   // at the moment only used for functions, and it cannot occur
   // there). TODO(marja): update this when it is.
   return ParseHoistableDeclaration(pos, flags, nullptr, false, ok);
 }
 
-PreParser::Statement PreParser::ParseForStatement(
-    ZoneList<const AstRawString*>* labels, bool* ok) {
-  // ForStatement ::
-  //   'for' '(' Expression? ';' Expression? ';' Expression? ')' Statement
-
-  // Create an in-between scope for let-bound iteration variables.
-  bool has_lexical = false;
-
-  BlockState block_state(&scope_state_);
-  Expect(Token::FOR, CHECK_OK);
-  Expect(Token::LPAREN, CHECK_OK);
-  if (peek() != Token::SEMICOLON) {
-    ForEachStatement::VisitMode mode;
-    if (peek() == Token::VAR || peek() == Token::CONST ||
-        (peek() == Token::LET && IsNextLetKeyword())) {
-      DeclarationParsingResult parsing_result;
-
-      ParseVariableDeclarations(kForStatement, &parsing_result, nullptr,
-                                CHECK_OK);
-      if (parsing_result.descriptor.mode == CONST ||
-          parsing_result.descriptor.mode == LET) {
-        has_lexical = true;
-      }
-      if (CheckInOrOf(&mode)) {
-        if (!*ok) return Statement::Default();
-        if (parsing_result.declarations.length() != 1) {
-          ReportMessageAt(parsing_result.bindings_loc,
-                          MessageTemplate::kForInOfLoopMultiBindings,
-                          ForEachStatement::VisitModeString(mode));
-          *ok = false;
-          return Statement::Default();
-        }
-        bool is_binding_pattern =
-            parsing_result.declarations[0].pattern.IsObjectLiteral() ||
-            parsing_result.declarations[0].pattern.IsArrayLiteral();
-        if (parsing_result.first_initializer_loc.IsValid() &&
-            (is_strict(language_mode()) || mode == ForEachStatement::ITERATE ||
-             has_lexical || is_binding_pattern || allow_harmony_for_in())) {
-          // Only increment the use count if we would have let this through
-          // without the flag.
-          if (use_counts_ != nullptr && allow_harmony_for_in()) {
-            ++use_counts_[v8::Isolate::kForInInitializer];
-          }
-          ReportMessageAt(parsing_result.first_initializer_loc,
-                          MessageTemplate::kForInOfLoopInitializer,
-                          ForEachStatement::VisitModeString(mode));
-          *ok = false;
-          return Statement::Default();
-        }
-
-        if (mode == ForEachStatement::ITERATE) {
-          ExpressionClassifier classifier(this);
-          ParseAssignmentExpression(true, CHECK_OK);
-          RewriteNonPattern(CHECK_OK);
-        } else {
-          ParseExpression(true, CHECK_OK);
-        }
-
-        Expect(Token::RPAREN, CHECK_OK);
-        {
-          ReturnExprScope no_tail_calls(function_state_,
-                                        ReturnExprContext::kInsideForInOfBody);
-          ParseScopedStatement(nullptr, true, CHECK_OK);
-        }
-        return Statement::Default();
-      }
-    } else {
-      int lhs_beg_pos = peek_position();
-      ExpressionClassifier classifier(this);
-      Expression lhs = ParseExpressionCoverGrammar(false, CHECK_OK);
-      int lhs_end_pos = scanner()->location().end_pos;
-      bool is_for_each = CheckInOrOf(&mode);
-      bool is_destructuring = is_for_each &&
-                              (lhs->IsArrayLiteral() || lhs->IsObjectLiteral());
-
-      if (is_destructuring) {
-        ValidateAssignmentPattern(CHECK_OK);
-      } else {
-        ValidateExpression(CHECK_OK);
-      }
-
-      if (is_for_each) {
-        if (!is_destructuring) {
-          lhs = CheckAndRewriteReferenceExpression(
-              lhs, lhs_beg_pos, lhs_end_pos, MessageTemplate::kInvalidLhsInFor,
-              kSyntaxError, CHECK_OK);
-        }
-
-        if (mode == ForEachStatement::ITERATE) {
-          ExpressionClassifier classifier(this);
-          ParseAssignmentExpression(true, CHECK_OK);
-          RewriteNonPattern(CHECK_OK);
-        } else {
-          ParseExpression(true, CHECK_OK);
-        }
-
-        Expect(Token::RPAREN, CHECK_OK);
-        {
-          BlockState block_state(&scope_state_);
-          ParseScopedStatement(nullptr, true, CHECK_OK);
-        }
-        return Statement::Default();
-      }
-    }
-  }
-
-  // Parsed initializer at this point.
-  Expect(Token::SEMICOLON, CHECK_OK);
-
-  // If there are let bindings, then condition and the next statement of the
-  // for loop must be parsed in a new scope.
-  Scope* inner_scope = scope();
-  // TODO(verwaest): Allocate this through a ScopeState as well.
-  if (has_lexical) inner_scope = NewScopeWithParent(inner_scope, BLOCK_SCOPE);
-
-  {
-    BlockState block_state(&scope_state_, inner_scope);
-
-    if (peek() != Token::SEMICOLON) {
-      ParseExpression(true, CHECK_OK);
-    }
-    Expect(Token::SEMICOLON, CHECK_OK);
-
-    if (peek() != Token::RPAREN) {
-      ParseExpression(true, CHECK_OK);
-    }
-    Expect(Token::RPAREN, CHECK_OK);
-
-    ParseScopedStatement(nullptr, true, ok);
-  }
-  return Statement::Default();
-}
-
-
 // Redefinition of CHECK_OK for parsing expressions.
 #undef CHECK_OK
 #define CHECK_OK CHECK_OK_VALUE(Expression::Default())
 
 PreParser::Expression PreParser::ParseFunctionLiteral(
     Identifier function_name, Scanner::Location function_name_location,
     FunctionNameValidity function_name_validity, FunctionKind kind,
     int function_token_pos, FunctionLiteral::FunctionType function_type,
     LanguageMode language_mode, bool* ok) {
   // Function ::
@@ skipping 162 matching lines @@
 
   body->Add(PreParserStatement::ExpressionStatement(return_value), zone());
 }
 
 #undef CHECK_OK
 #undef CHECK_OK_CUSTOM
 
 
 }  // namespace internal
 }  // namespace v8