[cleanup] Remove redundant fields from DeclarationDescriptor

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-literal-reindexer.h"
 #include "src/ast/scopeinfo.h"
@@ skipping 2007 matching lines @@
 }
 
 
 VariableProxy* Parser::NewUnresolved(const AstRawString* name,
                                      VariableMode mode) {
   // If we are inside a function, a declaration of a var/const variable is a
   // truly local variable, and the scope of the variable is always the function
   // scope.
   // Let/const variables in harmony mode are always added to the immediately
   // enclosing scope.
-  return DeclarationScope(mode)->NewUnresolved(
-      factory(), name, Variable::NORMAL, scanner()->location().beg_pos,
-      scanner()->location().end_pos);
+  Scope* scope =
+      IsLexicalVariableMode(mode) ? scope_ : scope_->DeclarationScope();
+  return scope->NewUnresolved(factory(), name, Variable::NORMAL,
+                              scanner()->location().beg_pos,
+                              scanner()->location().end_pos);
 }
 
 
 Variable* Parser::Declare(Declaration* declaration,
                           DeclarationDescriptor::Kind declaration_kind,
                           bool resolve, bool* ok, Scope* scope) {
   VariableProxy* proxy = declaration->proxy();
   DCHECK(proxy->raw_name() != NULL);
   const AstRawString* name = proxy->raw_name();
   VariableMode mode = declaration->mode();
@@ skipping 162 matching lines @@
       Expect(Token::COMMA, CHECK_OK);
     }
   }
   Expect(Token::RPAREN, CHECK_OK);
   Expect(Token::SEMICOLON, CHECK_OK);
 
   // Make sure that the function containing the native declaration
   // isn't lazily compiled. The extension structures are only
   // accessible while parsing the first time not when reparsing
   // because of lazy compilation.
-  DeclarationScope(VAR)->ForceEagerCompilation();
+  // TODO(adamk): Should this be ClosureScope()?
+  scope_->DeclarationScope()->ForceEagerCompilation();
 
   // TODO(1240846): It's weird that native function declarations are
   // introduced dynamically when we meet their declarations, whereas
   // other functions are set up when entering the surrounding scope.
   VariableProxy* proxy = NewUnresolved(name, VAR);
   Declaration* declaration =
       factory()->NewVariableDeclaration(proxy, VAR, scope_, pos);
   Declare(declaration, DeclarationDescriptor::NORMAL, true, CHECK_OK);
   NativeFunctionLiteral* lit = factory()->NewNativeFunctionLiteral(
       name, extension_, RelocInfo::kNoPosition);
@@ skipping 216 matching lines @@
   parsing_result->descriptor.parser = this;
   parsing_result->descriptor.declaration_kind = DeclarationDescriptor::NORMAL;
   parsing_result->descriptor.declaration_pos = peek_position();
   parsing_result->descriptor.initialization_pos = peek_position();
   parsing_result->descriptor.mode = VAR;
   // True if the binding needs initialization. 'let' and 'const' declared
   // bindings are created uninitialized by their declaration nodes and
   // need initialization. 'var' declared bindings are always initialized
   // immediately by their declaration nodes.
   parsing_result->descriptor.needs_init = false;
-  parsing_result->descriptor.is_const = false;
   if (peek() == Token::VAR) {
     if (is_strong(language_mode())) {
       Scanner::Location location = scanner()->peek_location();
       ReportMessageAt(location, MessageTemplate::kStrongVar);
       *ok = false;
       return;
     }
     Consume(Token::VAR);
   } else if (peek() == Token::CONST && allow_const()) {
     Consume(Token::CONST);
     if (is_sloppy(language_mode()) && allow_legacy_const()) {
       parsing_result->descriptor.mode = CONST_LEGACY;
       ++use_counts_[v8::Isolate::kLegacyConst];
     } else {
       DCHECK(is_strict(language_mode()) || allow_harmony_sloppy());
       DCHECK(var_context != kStatement);
       parsing_result->descriptor.mode = CONST;
     }
-    parsing_result->descriptor.is_const = true;
     parsing_result->descriptor.needs_init = true;
   } else if (peek() == Token::LET && allow_let()) {
     Consume(Token::LET);
     DCHECK(var_context != kStatement);
     parsing_result->descriptor.mode = LET;
     parsing_result->descriptor.needs_init = true;
   } else {
     UNREACHABLE();  // by current callers
   }
 
-  parsing_result->descriptor.declaration_scope =
-      DeclarationScope(parsing_result->descriptor.mode);
   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();
 
@@ skipping 662 matching lines @@
 
       block_scope->set_start_position(scanner()->location().beg_pos);
       {
         BlockState block_state(&scope_, block_scope);
         Target target(&this->target_stack_, catch_block);
 
         if (!is_simple) {
           DeclarationDescriptor descriptor;
           descriptor.declaration_kind = DeclarationDescriptor::NORMAL;
           descriptor.parser = this;
-          descriptor.declaration_scope = scope_;
           descriptor.scope = scope_;
           descriptor.hoist_scope = nullptr;
           descriptor.mode = LET;
-          descriptor.is_const = false;
           descriptor.needs_init = true;
           descriptor.declaration_pos = pattern->position();
           descriptor.initialization_pos = pattern->position();
 
           DeclarationParsingResult::Declaration decl(
               pattern, pattern->position(),
               factory()->NewVariableProxy(catch_variable));
 
           PatternRewriter::DeclareAndInitializeVariables(
               catch_block, &descriptor, &decl, nullptr, CHECK_OK);
@@ skipping 1350 matching lines @@
     const ParserFormalParameters& parameters, bool* ok) {
   DCHECK(!parameters.is_simple);
   DCHECK(scope_->is_function_scope());
   Block* init_block =
       factory()->NewBlock(NULL, 1, true, RelocInfo::kNoPosition);
   for (int i = 0; i < parameters.params.length(); ++i) {
     auto parameter = parameters.params[i];
     DeclarationDescriptor descriptor;
     descriptor.declaration_kind = DeclarationDescriptor::PARAMETER;
     descriptor.parser = this;
-    descriptor.declaration_scope = scope_;
     descriptor.scope = scope_;
     descriptor.hoist_scope = nullptr;
     descriptor.mode = LET;
-    descriptor.is_const = false;
     descriptor.needs_init = true;
     descriptor.declaration_pos = parameter.pattern->position();
     // The position that will be used by the AssignmentExpression
     // which copies from the temp parameter to the pattern.
     //
     // TODO(adamk): Should this be RelocInfo::kNoPosition, since
     // it's just copying from a temp var to the real param var?
     descriptor.initialization_pos = parameter.pattern->position();
     // The initializer position which will end up in,
     // Variable::initializer_position(), used for hole check elimination.
@@ skipping 1901 matching lines @@
 }
 
 
 void Parser::RaiseLanguageMode(LanguageMode mode) {
   SetLanguageMode(scope_,
                   static_cast<LanguageMode>(scope_->language_mode() | mode));
 }
 
 }  // namespace internal
 }  // namespace v8