Remove rest_parameter_ cache on DeclarationScope

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 187 matching lines @@
   asm_module_ = false;
   asm_function_ = false;
   force_eager_compilation_ = false;
   has_arguments_parameter_ = false;
   receiver_ = nullptr;
   new_target_ = nullptr;
   function_ = nullptr;
   arguments_ = nullptr;
   this_function_ = nullptr;
   arity_ = 0;
-  rest_parameter_ = nullptr;
   rest_index_ = -1;
 }
 
 void Scope::SetDefaults() {
 #ifdef DEBUG
   scope_name_ = nullptr;
   already_resolved_ = false;
 #endif
   inner_scope_ = nullptr;
   sibling_ = nullptr;
@@ skipping 469 matching lines @@
     var = NewTemporary(name);
   } else {
     var = Declare(zone(), this, name, mode, Variable::NORMAL,
                   kCreatedInitialized);
     // TODO(wingo): Avoid O(n^2) check.
     *is_duplicate = IsDeclaredParameter(name);
   }
   if (!is_optional && !is_rest && arity_ == params_.length()) {
     ++arity_;
   }
-  if (is_rest) {
-    DCHECK_NULL(rest_parameter_);
-    rest_parameter_ = var;
-    rest_index_ = num_parameters();
-  }
+  if (is_rest) rest_index_ = num_parameters();
   params_.Add(var, zone());
   if (name == ast_value_factory->arguments_string()) {
     has_arguments_parameter_ = true;
   }
   return var;
 }
 
 Variable* Scope::DeclareLocal(const AstRawString* name, VariableMode mode,
                               InitializationFlag init_flag, Variable::Kind kind,
                               MaybeAssignedFlag maybe_assigned_flag) {
@@ skipping 824 matching lines @@
     } else {
       // 'arguments' is unused. Tell the code generator that it does not need to
       // allocate the arguments object by nulling out arguments_.
       arguments_ = nullptr;
     }
 
   } else {
     DCHECK(is_arrow_scope());
   }
 
-  if (rest_parameter_ && !MustAllocate(rest_parameter_)) {
-    rest_parameter_ = nullptr;
-  }
-
   // The same parameter may occur multiple times in the parameters_ list.
   // If it does, and if it is not copied into the context object, it must
   // receive the highest parameter index for that parameter; thus iteration
   // order is relevant!
   for (int i = params_.length() - 1; i >= 0; --i) {
+    if (i == rest_index_) continue;
     Variable* var = params_[i];
-    if (var == rest_parameter_) continue;
 
     DCHECK(var->scope() == this);
     if (uses_sloppy_arguments) {
       var->ForceContextAllocation();
     }
     AllocateParameter(var, i);
   }
 }
 
 void DeclarationScope::AllocateParameter(Variable* var, int index) {
@@ skipping 73 matching lines @@
 
 void DeclarationScope::AllocateLocals() {
   // 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_);
   }
 
-  DCHECK(rest_parameter_ == nullptr || !rest_parameter_->IsUnallocated());
+  DCHECK(!has_rest_parameter() || !MustAllocate(params_[rest_index_]) ||
+         !params_[rest_index_]->IsUnallocated());
 
   if (new_target_ != nullptr && !MustAllocate(new_target_)) {
     new_target_ = nullptr;
   }
 
   if (this_function_ != nullptr && !MustAllocate(this_function_)) {
     this_function_ = nullptr;
   }
 }
 
@@ skipping 72 matching lines @@
       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