[modules] Minor refactorings in scopes and scopeinfos.

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 117 matching lines @@
                                    FunctionKind function_kind)
     : Scope(zone, outer_scope, scope_type),
       function_kind_(function_kind),
       temps_(4, zone),
       params_(4, zone),
       sloppy_block_function_map_(zone) {
   SetDefaults();
   asm_function_ = outer_scope_->IsAsmModule();
 }
 
-ModuleScope::ModuleScope(Zone* zone, DeclarationScope* script_scope,
+ModuleScope::ModuleScope(DeclarationScope* script_scope,
                          AstValueFactory* ast_value_factory)
-    : DeclarationScope(zone, script_scope, MODULE_SCOPE) {
+    : DeclarationScope(ast_value_factory->zone(), script_scope, MODULE_SCOPE) {
+  Zone* zone = ast_value_factory->zone();
   module_descriptor_ = new (zone) ModuleDescriptor(zone);
   set_language_mode(STRICT);
   DeclareThis(ast_value_factory);
 }
 
 Scope::Scope(Zone* zone, ScopeType scope_type, Handle<ScopeInfo> scope_info)
     : zone_(zone),
       outer_scope_(nullptr),
       variables_(zone),
       ordered_variables_(0, zone),
@@ skipping 440 matching lines @@
 
 Variable* Scope::LookupInScopeInfo(const AstRawString* name) {
   Handle<String> name_handle = name->string();
   // The Scope is backed up by ScopeInfo. This means it cannot operate in a
   // heap-independent mode, and all strings must be internalized immediately. So
   // it's ok to get the Handle<String> here.
   // If we have a serialized scope info, we might find the variable there.
   // There should be no local slot with the given name.
   DCHECK(scope_info_->StackSlotIndex(*name_handle) < 0);
 
-  // Check context slot lookup.
   VariableMode mode;
-  VariableLocation location = VariableLocation::CONTEXT;
   InitializationFlag init_flag;
   MaybeAssignedFlag maybe_assigned_flag;
+
+  VariableLocation location = VariableLocation::CONTEXT;
   int index = ScopeInfo::ContextSlotIndex(scope_info_, name_handle, &mode,
                                           &init_flag, &maybe_assigned_flag);
   if (index < 0) {
     location = VariableLocation::GLOBAL;
     index = ScopeInfo::ContextGlobalSlotIndex(scope_info_, name_handle, &mode,
                                               &init_flag, &maybe_assigned_flag);
+    DCHECK(index < 0 || (is_script_scope() && IsDeclaredVariableMode(mode) &&
+                         !IsLexicalVariableMode(mode)));

[adamk, 2016/08/25 16:04:08]

You should actually be able to tighten this one more bit: mode == VAR (no
CONST_LEGACY globals)

   }
   if (index < 0) {
-    // Check parameters.
+    location = VariableLocation::LOOKUP;

[adamk, 2016/08/25 16:04:09]

Why did this move out of the "found a parameter" block?

     index = scope_info_->ParameterIndex(*name_handle);
-    if (index < 0) return NULL;
-
-    mode = DYNAMIC;
-    location = VariableLocation::LOOKUP;
-    init_flag = kCreatedInitialized;
-    // Be conservative and flag parameters as maybe assigned. Better information
-    // would require ScopeInfo to serialize the maybe_assigned bit also for
-    // parameters.
-    maybe_assigned_flag = kMaybeAssigned;
-  } else {
-    DCHECK(location != VariableLocation::GLOBAL ||
-           (is_script_scope() && IsDeclaredVariableMode(mode) &&
-            !IsLexicalVariableMode(mode)));
+    if (index >= 0) {
+      mode = DYNAMIC;
+      init_flag = kCreatedInitialized;
+      // Be conservative and flag parameters as maybe assigned. Better
+      // information would require ScopeInfo to serialize the maybe_assigned bit
+      // also for parameters.
+      maybe_assigned_flag = kMaybeAssigned;
+    }
   }
+  if (index < 0 && scope_type() == MODULE_SCOPE) {
+    location = VariableLocation::MODULE;
+    index = -1;  // TODO(neis): Find module variables in scope info.
+  }
+  if (index < 0) return nullptr;  // Nowhere found.
 
   Variable::Kind kind = Variable::NORMAL;
   if (location == VariableLocation::CONTEXT &&
       index == scope_info_->ReceiverContextSlotIndex()) {
     kind = Variable::THIS;
   }
   // 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,
@@ skipping 155 matching lines @@
         if (decls_[j]->proxy()->raw_name() == name) {
           return decls_[j];
         }
       }
       DCHECK(false);
     }
   }
   return nullptr;
 }
 
-void Scope::CollectStackAndContextLocals(ZoneList<Variable*>* stack_locals,
-                                         ZoneList<Variable*>* context_locals,
-                                         ZoneList<Variable*>* context_globals) {
+void Scope::CollectVariables(ZoneList<Variable*>* stack_locals,
+                             ZoneList<Variable*>* context_locals,
+                             ZoneList<Variable*>* context_globals) {
   DCHECK(stack_locals != NULL);
   DCHECK(context_locals != NULL);
   DCHECK(context_globals != NULL);
 
   // Collect temporaries which are always allocated on the stack, unless the
   // context as a whole has forced context allocation.
   if (is_declaration_scope()) {
     ZoneList<Variable*>* temps = AsDeclarationScope()->temps();
     for (int i = 0; i < temps->length(); i++) {
       Variable* var = (*temps)[i];
@@ skipping 848 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