Function name variable does not need a VariableDeclaration

src/ast/scopes.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/ast/scopes.h"
 
 #include <set>
 
 #include "src/accessors.h"
 #include "src/bootstrapper.h"
@@ skipping 315 matching lines @@
     VariableLocation location = VariableLocation::LOOKUP;
     Variable::Kind kind = Variable::NORMAL;
 
     Variable* result = variables_.Declare(zone(), this, name, mode, kind,
                                           init_flag, maybe_assigned_flag);
     result->AllocateTo(location, index);
   }
 
   // Internalize function proxy for this scope.
   if (scope_info_->HasFunctionName()) {
-    AstNodeFactory factory(ast_value_factory);
     Handle<String> name_handle(scope_info_->FunctionName(), isolate);
     const AstRawString* name = ast_value_factory->GetString(name_handle);
     VariableMode mode;
     int index = scope_info_->FunctionContextSlotIndex(*name_handle, &mode);
     if (index >= 0) {
-      Variable* result = new (zone())
-          Variable(this, name, mode, Variable::NORMAL, kCreatedInitialized);
-      VariableProxy* proxy = factory.NewVariableProxy(result);
-      VariableDeclaration* declaration =
-          factory.NewVariableDeclaration(proxy, this, kNoSourcePosition);
-      AsDeclarationScope()->DeclareFunctionVar(declaration);
+      Variable* result = AsDeclarationScope()->DeclareFunctionVar(name);
+      DCHECK_EQ(mode, result->mode());
       result->AllocateTo(VariableLocation::CONTEXT, index);
     }
   }
 
   scope_info_ = Handle<ScopeInfo>::null();
 }
 
 DeclarationScope* Scope::AsDeclarationScope() {
   DCHECK(is_declaration_scope());
   return static_cast<DeclarationScope*>(this);
@@ skipping 65 matching lines @@
                          CONST, Variable::NORMAL, kCreatedInitialized);
 
   if (IsConciseMethod(function_kind_) || IsClassConstructor(function_kind_) ||
       IsAccessorFunction(function_kind_)) {
     this_function_ = variables_.Declare(
         zone(), this, ast_value_factory->this_function_string(), CONST,
         Variable::NORMAL, kCreatedInitialized);
   }
 }
 
+Variable* DeclarationScope::DeclareFunctionVar(const AstRawString* name) {
+  DCHECK(is_function_scope());
+  DCHECK_NULL(function_);
+  VariableMode mode = is_strict(language_mode()) ? CONST : CONST_LEGACY;
+  function_ = new (zone())
+      Variable(this, name, mode, Variable::NORMAL, kCreatedInitialized);
+  return function_;
+}
 
 Scope* Scope::FinalizeBlockScope() {
   DCHECK(is_block_scope());
 
   if (variables_.occupancy() > 0 ||
       (is_declaration_scope() && calls_sloppy_eval())) {
     return this;
   }
 
   // Remove this scope from outer scope.
@@ skipping 147 matching lines @@
   }
   // TODO(marja, rossberg): Correctly declare FUNCTION, CLASS, NEW_TARGET, and
   // ARGUMENTS bindings as their corresponding Variable::Kind.
 
   Variable* var = variables_.Declare(zone(), this, name, mode, kind, init_flag,
                                      maybe_assigned_flag);
   var->AllocateTo(location, index);
   return var;
 }
 
-Variable* DeclarationScope::LookupFunctionVar(const AstRawString* name,
-                                              AstNodeFactory* factory) {
-  if (function_ != NULL && function_->proxy()->raw_name() == name) {
-    return function_->proxy()->var();
+Variable* DeclarationScope::LookupFunctionVar(const AstRawString* name) {
+  if (function_ != nullptr && function_->raw_name() == name) {
+    return function_;
   } else if (!scope_info_.is_null()) {
     // If we are backed by a scope info, try to lookup the variable there.
     VariableMode mode;
     int index = scope_info_->FunctionContextSlotIndex(*(name->string()), &mode);
-    if (index < 0) return NULL;
-    Variable* var = new (zone())
-        Variable(this, name, mode, Variable::NORMAL, kCreatedInitialized);
-    DCHECK_NOT_NULL(factory);
-    VariableProxy* proxy = factory->NewVariableProxy(var);
-    VariableDeclaration* declaration =
-        factory->NewVariableDeclaration(proxy, this, kNoSourcePosition);
-    DCHECK_EQ(factory->zone(), zone());
-    DeclareFunctionVar(declaration);
+    if (index < 0) return nullptr;
+    Variable* var = DeclareFunctionVar(name);
+    DCHECK_EQ(mode, var->mode());
     var->AllocateTo(VariableLocation::CONTEXT, index);
     return var;
   } else {
-    return NULL;
+    return nullptr;
   }
 }
 
 
 Variable* Scope::Lookup(const AstRawString* name) {
   for (Scope* scope = this;
        scope != NULL;
        scope = scope->outer_scope()) {
     Variable* var = scope->LookupLocal(name);
     if (var != NULL) return var;
@@ skipping 107 matching lines @@
   DCHECK(!already_resolved());
   decls_.Add(declaration, zone());
 }
 
 
 Declaration* Scope::CheckConflictingVarDeclarations() {
   int length = decls_.length();
   for (int i = 0; i < length; i++) {
     Declaration* decl = decls_[i];
     VariableMode mode = decl->proxy()->var()->mode();
-    // We don't create a separate scope to hold the function name of a function
-    // expression, so we have to make sure not to consider it when checking for
-    // conflicts (since it's conceptually "outside" the declaration scope).
-    if (is_function_scope() && decl == AsDeclarationScope()->function())
-      continue;
     if (IsLexicalVariableMode(mode) && !is_block_scope()) continue;
 
     // Iterate through all scopes until and including the declaration scope.
     Scope* previous = NULL;
     Scope* current = decl->scope();
     // Lexical vs lexical conflicts within the same scope have already been
     // captured in Parser::Declare. The only conflicts we still need to check
     // are lexical vs VAR, or any declarations within a declaration block scope
     // vs lexical declarations in its surrounding (function) scope.
     if (IsLexicalVariableMode(mode)) current = current->outer_scope_;
@@ skipping 376 matching lines @@
   FunctionKind function_kind = is_function_scope()
                                    ? AsDeclarationScope()->function_kind()
                                    : kNormalFunction;
   Indent(n0, Header(scope_type_, function_kind, is_declaration_scope()));
   if (scope_name_ != nullptr && !scope_name_->IsEmpty()) {
     PrintF(" ");
     PrintName(scope_name_);
   }
 
   // Print parameters, if any.
-  VariableDeclaration* function = nullptr;
+  Variable* function = nullptr;
   if (is_function_scope()) {
     AsDeclarationScope()->PrintParameters();
-    function = AsDeclarationScope()->function();
+    function = AsDeclarationScope()->function_var();
   }
 
   PrintF(" { // (%d, %d)\n", start_position(), end_position());
 
   // Function name, if any (named function literals, only).
   if (function != nullptr) {
     Indent(n1, "// (local) function name: ");
-    PrintName(function->proxy()->raw_name());
+    PrintName(function->raw_name());
     PrintF("\n");
   }
 
   // Scope info.
   if (HasTrivialOuterContext()) {
     Indent(n1, "// scope has trivial outer context\n");
   }
   if (is_strict(language_mode())) {
     Indent(n1, "// strict mode scope\n");
   }
@@ skipping 13 matching lines @@
   }
   if (num_heap_slots_ > 0) {
     Indent(n1, "// ");
     PrintF("%d heap slots (including %d global slots)\n", num_heap_slots_,
            num_global_slots_);
   }
 
   // Print locals.
   if (function != nullptr) {
     Indent(n1, "// function var:\n");
-    PrintVar(n1, function->proxy()->var());
+    PrintVar(n1, function);
   }
 
   if (is_declaration_scope()) {
     bool printed_header = false;
     ZoneList<Variable*>* temps = AsDeclarationScope()->temps();
     for (int i = 0; i < temps->length(); i++) {
       if ((*temps)[i] != nullptr) {
         if (!printed_header) {
           printed_header = true;
           Indent(n1, "// temporary vars:\n");
@@ skipping 81 matching lines @@
   // this scope which introduces the same variable again, the resulting
   // variable remains the same.)
   if (var != NULL) {
     *binding_kind = BOUND;
     return var;
   }
 
   // We did not find a variable locally. Check against the function variable, if
   // any.
   *binding_kind = UNBOUND;
-  var =
-      is_function_scope()
-          ? AsDeclarationScope()->LookupFunctionVar(proxy->raw_name(), factory)
-          : nullptr;
+  var = is_function_scope()
+            ? AsDeclarationScope()->LookupFunctionVar(proxy->raw_name())
+            : nullptr;
   if (var != NULL) {
     *binding_kind = BOUND;
   } else if (outer_scope_ != nullptr && this != max_outer_scope) {
     var = outer_scope_->LookupRecursive(proxy, binding_kind, factory,
                                         max_outer_scope);
     if (*binding_kind == BOUND && is_function_scope()) {
       var->ForceContextAllocation();
     }
   } else {
     DCHECK(is_script_scope() || this == max_outer_scope);
@@ skipping 380 matching lines @@
     AsDeclarationScope()->AllocateLocals(ast_value_factory);
   }
 }
 
 void DeclarationScope::AllocateLocals(AstValueFactory* ast_value_factory) {
   // For now, function_ must be allocated at the very end.  If it gets
   // allocated in the context, it must be the last slot in the context,
   // because of the current ScopeInfo implementation (see
   // ScopeInfo::ScopeInfo(FunctionScope* scope) constructor).
   if (function_ != nullptr) {
-    AllocateNonParameterLocal(function_->proxy()->var(), ast_value_factory);
+    AllocateNonParameterLocal(function_, ast_value_factory);
   }
 
   if (rest_parameter_ != nullptr) {
     AllocateNonParameterLocal(rest_parameter_, ast_value_factory);
   }
 
   if (new_target_ != nullptr && !MustAllocate(new_target_)) {
     new_target_ = nullptr;
   }
 
@@ skipping 58 matching lines @@
   if (num_heap_slots_ == Context::MIN_CONTEXT_SLOTS && !must_have_context) {
     num_heap_slots_ = 0;
   }
 
   // Allocation done.
   DCHECK(num_heap_slots_ == 0 || num_heap_slots_ >= Context::MIN_CONTEXT_SLOTS);
 }
 
 
 int Scope::StackLocalCount() const {
-  VariableDeclaration* function =
-      is_function_scope() ? AsDeclarationScope()->function() : nullptr;
+  Variable* function =
+      is_function_scope() ? AsDeclarationScope()->function_var() : nullptr;
   return num_stack_slots() -
-         (function != NULL && function->proxy()->var()->IsStackLocal() ? 1 : 0);
+         (function != nullptr && function->IsStackLocal() ? 1 : 0);
 }
 
 
 int Scope::ContextLocalCount() const {
   if (num_heap_slots() == 0) return 0;
-  VariableDeclaration* function =
-      is_function_scope() ? AsDeclarationScope()->function() : nullptr;
+  Variable* function =
+      is_function_scope() ? AsDeclarationScope()->function_var() : nullptr;
   bool is_function_var_in_context =
-      function != NULL && function->proxy()->var()->IsContextSlot();
+      function != nullptr && function->IsContextSlot();
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS - num_global_slots() -
          (is_function_var_in_context ? 1 : 0);
 }
 
 
 int Scope::ContextGlobalCount() const { return num_global_slots(); }
 
 }  // namespace internal
 }  // namespace v8