Don't track function-kind through FunctionState, always read from underlying scope

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 363 matching lines @@
     kInsideValidBlock,
 
     // Tail call expressions are not allowed in the following blocks.
     kInsideTryBlock,
     kInsideForInOfBody,
   };
 
   class FunctionState final : public ScopeState {
    public:
     FunctionState(FunctionState** function_state_stack,
-                  ScopeState** scope_stack, DeclarationScope* scope,
-                  FunctionKind kind);
+                  ScopeState** scope_stack, DeclarationScope* scope);
     ~FunctionState();
 
     DeclarationScope* scope() const {
       return ScopeState::scope()->AsDeclarationScope();
     }
 
     int NextMaterializedLiteralIndex() {
       return next_materialized_literal_index_++;
     }
     int materialized_literal_count() {
       return next_materialized_literal_index_;
     }
 
     void SkipMaterializedLiterals(int count) {
       next_materialized_literal_index_ += count;
     }
 
     void AddProperty() { expected_property_count_++; }
     int expected_property_count() { return expected_property_count_; }
 
-    bool is_generator() const { return IsGeneratorFunction(kind_); }
-    bool is_async_function() const { return IsAsyncFunction(kind_); }
+    bool is_generator() const { return IsGeneratorFunction(kind()); }
+    bool is_async_function() const { return IsAsyncFunction(kind()); }
     bool is_resumable() const { return is_generator() || is_async_function(); }
 
-    FunctionKind kind() const { return kind_; }
+    FunctionKind kind() const { return scope()->function_kind(); }
     FunctionState* outer() const { return outer_function_state_; }
 
     void set_generator_object_variable(typename Types::Variable* variable) {
       DCHECK(variable != NULL);
       DCHECK(is_resumable());
       generator_object_variable_ = variable;
     }
     typename Types::Variable* generator_object_variable() const {
       return generator_object_variable_;
     }
@@ skipping 70 matching lines @@
     }
 
     // Used to assign an index to each literal that needs materialization in
     // the function.  Includes regexp literals, and boilerplate for object and
     // array literals.
     int next_materialized_literal_index_;
 
     // Properties count estimation.
     int expected_property_count_;
 
-    FunctionKind kind_;
     // For generators, this variable may hold the generator object. It variable
     // is used by yield expressions and return statements. It is not necessary
     // for generator functions to have this variable set.
     Variable* generator_object_variable_;
     // For async functions, this variable holds a temporary for the Promise
     // being created as output of the async function.
     Variable* promise_variable_;
 
     FunctionState** function_state_stack_;
     FunctionState* outer_function_state_;
@@ skipping 673 matching lines @@
   ExpressionT ParseBinaryExpression(int prec, bool accept_IN, bool* ok);
   ExpressionT ParseUnaryExpression(bool* ok);
   ExpressionT ParsePostfixExpression(bool* ok);
   ExpressionT ParseLeftHandSideExpression(bool* ok);
   ExpressionT ParseMemberWithNewPrefixesExpression(bool* is_async, bool* ok);
   ExpressionT ParseMemberExpression(bool* is_async, bool* ok);
   ExpressionT ParseMemberExpressionContinuation(ExpressionT expression,
                                                 bool* is_async, bool* ok);
   ExpressionT ParseArrowFunctionLiteral(bool accept_IN,
                                         const FormalParametersT& parameters,
-                                        bool is_async,
                                         bool* ok);
   ExpressionT ParseTemplateLiteral(ExpressionT tag, int start, bool* ok);
   ExpressionT ParseSuperExpression(bool is_new, bool* ok);
   ExpressionT ParseNewTargetExpression(bool* ok);
 
   void ParseFormalParameter(FormalParametersT* parameters, bool* ok);
   void ParseFormalParameterList(FormalParametersT* parameters, bool* ok);
   void CheckArityRestrictions(int param_count, FunctionKind function_type,
                               bool has_rest, int formals_start_pos,
                               int formals_end_pos, bool* ok);
@@ skipping 241 matching lines @@
   bool allow_harmony_restrictive_generators_;
   bool allow_harmony_trailing_commas_;
   bool allow_harmony_class_fields_;
 
   friend class DiscardableZoneScope;
 };
 
 template <typename Impl>
 ParserBase<Impl>::FunctionState::FunctionState(
     FunctionState** function_state_stack, ScopeState** scope_stack,
-    DeclarationScope* scope, FunctionKind kind)
+    DeclarationScope* scope)
     : ScopeState(scope_stack, scope),
       next_materialized_literal_index_(0),
       expected_property_count_(0),
-      kind_(kind),
       generator_object_variable_(nullptr),
       promise_variable_(nullptr),
       function_state_stack_(function_state_stack),
       outer_function_state_(*function_state_stack),
       destructuring_assignments_to_rewrite_(16, scope->zone()),
       tail_call_expressions_(scope->zone()),
       return_expr_context_(ReturnExprContext::kInsideValidBlock),
       non_patterns_to_rewrite_(0, scope->zone()),
       reported_errors_(16, scope->zone()),
       next_function_is_parenthesized_(false),
@@ skipping 786 matching lines @@
 template <typename Impl>
 typename ParserBase<Impl>::FunctionLiteralT
 ParserBase<Impl>::ParseClassFieldForInitializer(bool has_initializer,
                                                 bool* ok) {
   // Makes a concise method which evaluates and returns the initialized value
   // (or undefined if absent).
   FunctionKind kind = FunctionKind::kConciseMethod;
   DeclarationScope* initializer_scope = NewFunctionScope(kind);
   initializer_scope->set_start_position(scanner()->location().end_pos);
   FunctionState initializer_state(&function_state_, &scope_state_,
-                                  initializer_scope, kind);
+                                  initializer_scope);
   DCHECK(scope() == initializer_scope);
   scope()->SetLanguageMode(STRICT);
   ExpressionClassifier expression_classifier(this);
   ExpressionT value;
   if (has_initializer) {
     value = this->ParseAssignmentExpression(
         true, CHECK_OK_CUSTOM(EmptyFunctionLiteral));
     impl()->RewriteNonPattern(CHECK_OK_CUSTOM(EmptyFunctionLiteral));
   } else {
     value = factory()->NewUndefinedLiteral(kNoSourcePosition);
@@ skipping 400 matching lines @@
 
     checkpoint.Restore(&parameters.materialized_literals_count);
 
     scope->set_start_position(lhs_beg_pos);
     Scanner::Location duplicate_loc = Scanner::Location::invalid();
     impl()->ParseArrowFunctionFormalParameterList(
         &parameters, expression, loc, &duplicate_loc, scope_snapshot, CHECK_OK);
     if (duplicate_loc.IsValid()) {
       classifier()->RecordDuplicateFormalParameterError(duplicate_loc);
     }
-    expression =
-        ParseArrowFunctionLiteral(accept_IN, parameters, is_async, CHECK_OK);
+    expression = ParseArrowFunctionLiteral(accept_IN, parameters, CHECK_OK);
     impl()->Discard();
     classifier()->RecordPatternError(arrow_loc,
                                      MessageTemplate::kUnexpectedToken,
                                      Token::String(Token::ARROW));
 
     if (fni_ != nullptr) fni_->Infer();
 
     return expression;
   }
 
@@ skipping 1177 matching lines @@
         peek_ahead == Token::SEMICOLON || peek_ahead == Token::RBRACK) {
       return true;
     }
   }
   return false;
 }
 
 template <typename Impl>
 typename ParserBase<Impl>::ExpressionT
 ParserBase<Impl>::ParseArrowFunctionLiteral(
-    bool accept_IN, const FormalParametersT& formal_parameters, bool is_async,
-    bool* ok) {
+    bool accept_IN, const FormalParametersT& formal_parameters, bool* ok) {
   if (peek() == Token::ARROW && scanner_->HasAnyLineTerminatorBeforeNext()) {
     // ASI inserts `;` after arrow parameters if a line terminator is found.
     // `=> ...` is never a valid expression, so report as syntax error.
     // If next token is not `=>`, it's a syntax error anyways.
     ReportUnexpectedTokenAt(scanner_->peek_location(), Token::ARROW);
     *ok = false;
     return impl()->EmptyExpression();
   }
 
   StatementListT body = impl()->NullStatementList();
   int num_parameters = formal_parameters.scope->num_parameters();
   int materialized_literal_count = -1;
   int expected_property_count = -1;
 
-  FunctionKind arrow_kind = is_async ? kAsyncArrowFunction : kArrowFunction;
+  FunctionKind kind = formal_parameters.scope->function_kind();
   FunctionLiteral::EagerCompileHint eager_compile_hint =
       FunctionLiteral::kShouldLazyCompile;
   bool should_be_used_once_hint = false;
   {
     FunctionState function_state(&function_state_, &scope_state_,
-                                 formal_parameters.scope, arrow_kind);
+                                 formal_parameters.scope);
 
     function_state.SkipMaterializedLiterals(
         formal_parameters.materialized_literals_count);
 
     impl()->ReindexLiterals(formal_parameters);
 
     Expect(Token::ARROW, CHECK_OK);
 
     if (peek() == Token::LBRACE) {
       // Multiple statement body
@@ skipping 25 matching lines @@
           // This is probably an initialization function. Inform the compiler it
           // should also eager-compile this function, and that we expect it to
           // be used once.
           eager_compile_hint = FunctionLiteral::kShouldEagerCompile;
           should_be_used_once_hint = true;
         }
       }
       if (!is_lazily_parsed) {
         body = impl()->ParseEagerFunctionBody(
             impl()->EmptyIdentifier(), kNoSourcePosition, formal_parameters,
-            arrow_kind, FunctionLiteral::kAnonymousExpression, CHECK_OK);
+            kind, FunctionLiteral::kAnonymousExpression, CHECK_OK);
         materialized_literal_count =
             function_state.materialized_literal_count();
         expected_property_count = function_state.expected_property_count();
       }
     } else {
       // Single-expression body
       int pos = position();
       DCHECK(ReturnExprContext::kInsideValidBlock ==
              function_state_->return_expr_context());
       ReturnExprScope allow_tail_calls(
           function_state_, ReturnExprContext::kInsideValidReturnStatement);
       body = impl()->NewStatementList(1);
-      impl()->AddParameterInitializationBlock(formal_parameters, body, is_async,
-                                              CHECK_OK);
+      impl()->AddParameterInitializationBlock(
+          formal_parameters, body, kind == kAsyncArrowFunction, CHECK_OK);
       ExpressionClassifier classifier(this);
-      if (is_async) {
+      if (kind == kAsyncArrowFunction) {
         impl()->ParseAsyncArrowSingleExpressionBody(body, accept_IN, pos,
                                                     CHECK_OK);
         impl()->RewriteNonPattern(CHECK_OK);
       } else {
         ExpressionT expression = ParseAssignmentExpression(accept_IN, CHECK_OK);
         impl()->RewriteNonPattern(CHECK_OK);
         body->Add(factory()->NewReturnStatement(expression, pos), zone());
         if (allow_tailcalls() && !is_sloppy(language_mode())) {
           // ES6 14.6.1 Static Semantics: IsInTailPosition
           impl()->MarkTailPosition(expression);
@@ skipping 21 matching lines @@
     }
     impl()->CheckConflictingVarDeclarations(formal_parameters.scope, CHECK_OK);
 
     impl()->RewriteDestructuringAssignments();
   }
 
   FunctionLiteralT function_literal = factory()->NewFunctionLiteral(
       impl()->EmptyIdentifierString(), formal_parameters.scope, body,
       materialized_literal_count, expected_property_count, num_parameters,
       FunctionLiteral::kNoDuplicateParameters,
-      FunctionLiteral::kAnonymousExpression, eager_compile_hint, arrow_kind,
+      FunctionLiteral::kAnonymousExpression, eager_compile_hint, kind,
       formal_parameters.scope->start_position());
 
   function_literal->set_function_token_position(
       formal_parameters.scope->start_position());
   if (should_be_used_once_hint) {
     function_literal->set_should_be_used_once_hint();
   }
 
   impl()->InferFunctionName(function_literal);
 
@@ skipping 1305 matching lines @@
     has_seen_constructor_ = true;
     return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_PARSING_PARSER_BASE_H