WIP: new.target

src/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/v8.h"
 
 #include "src/accessors.h"
 #include "src/bootstrapper.h"
 #include "src/messages.h"
 #include "src/parser.h"
@@ skipping 138 matching lines @@
   new_target_ = nullptr;
   function_ = NULL;
   arguments_ = NULL;
   illegal_redecl_ = NULL;
   scope_inside_with_ = false;
   scope_contains_with_ = false;
   scope_calls_eval_ = false;
   scope_uses_arguments_ = false;
   scope_uses_super_property_ = false;
   scope_uses_this_ = false;
+  scope_uses_new_target_ = false;
   asm_module_ = false;
   asm_function_ = outer_scope != NULL && outer_scope->asm_module_;
   // Inherit the language mode from the parent scope.
   language_mode_ = outer_scope != NULL ? outer_scope->language_mode_ : SLOPPY;
   outer_scope_calls_sloppy_eval_ = false;
   inner_scope_calls_eval_ = false;
   inner_scope_uses_arguments_ = false;
   inner_scope_uses_this_ = false;
+  inner_scope_uses_new_target_ = false;
   inner_scope_uses_super_property_ = false;
   force_eager_compilation_ = false;
   force_context_allocation_ = (outer_scope != NULL && !is_function_scope())
       ? outer_scope->has_forced_context_allocation() : false;
   num_var_or_const_ = 0;
   num_stack_slots_ = 0;
   num_heap_slots_ = 0;
   num_modules_ = 0;
   module_var_ = NULL,
   rest_parameter_ = NULL;
@@ skipping 132 matching lines @@
   // invoking scripts
   if (is_declaration_scope()) {
     DCHECK(!subclass_constructor || is_function_scope());
     Variable* var = variables_.Declare(
         this, ast_value_factory_->this_string(),
         subclass_constructor ? CONST : VAR, Variable::THIS,
         subclass_constructor ? kNeedsInitialization : kCreatedInitialized);
     var->AllocateTo(Variable::PARAMETER, -1);
     receiver_ = var;
 
-    if (subclass_constructor) {
-      new_target_ =
-          variables_.Declare(this, ast_value_factory_->new_target_string(),
-                             CONST, Variable::NEW_TARGET, kCreatedInitialized);
-      new_target_->AllocateTo(Variable::PARAMETER, -2);
-      new_target_->set_is_used();
-    }
+    // if (subclass_constructor) {
+    //   new_target_ =
+    //       variables_.Declare(this, ast_value_factory_->new_target_string(),
+    //                          CONST, Variable::NEW_TARGET,
+    //                          kCreatedInitialized);
+    //   new_target_->AllocateTo(Variable::PARAMETER, -2);
+    //   new_target_->set_is_used();
+    // }
   } else {
     DCHECK(outer_scope() != NULL);
     receiver_ = outer_scope()->receiver();
   }
 
   if (is_function_scope() && !is_arrow_scope()) {
     // Declare 'arguments' variable which exists in all non arrow functions.
     // Note that it might never be accessed, in which case it won't be
     // allocated during variable allocation.
     variables_.Declare(this,
                        ast_value_factory_->arguments_string(),
                        VAR,
                        Variable::ARGUMENTS,
                        kCreatedInitialized);
+
+    variables_.Declare(this, ast_value_factory_->new_target_string(), CONST,
+                       Variable::NEW_TARGET, kNeedsInitialization);
   }
 }
 
 
 Scope* Scope::FinalizeBlockScope() {
   DCHECK(is_block_scope());
   DCHECK(internals_.is_empty());
   DCHECK(temps_.is_empty());
   DCHECK(params_.is_empty());
 
@@ skipping 14 matching lines @@
 
   // Move unresolved variables
   for (int i = 0; i < unresolved_.length(); i++) {
     outer_scope()->unresolved_.Add(unresolved_[i], zone());
   }
 
   // Propagate usage flags to outer scope.
   if (uses_arguments()) outer_scope_->RecordArgumentsUsage();
   if (uses_super_property()) outer_scope_->RecordSuperPropertyUsage();
   if (uses_this()) outer_scope_->RecordThisUsage();
+  if (uses_new_target()) outer_scope_->RecordNewTargetUsage();
 
   return NULL;
 }
 
 
 Variable* Scope::LookupLocal(const AstRawString* name) {
   Variable* result = variables_.Lookup(name);
   if (result != NULL || scope_info_.is_null()) {
     return result;
   }
@@ skipping 526 matching lines @@
   } else if (is_strict(language_mode())) {
     Indent(n1, "// strict mode scope\n");
   }
   if (scope_inside_with_) Indent(n1, "// scope inside 'with'\n");
   if (scope_contains_with_) Indent(n1, "// scope contains 'with'\n");
   if (scope_calls_eval_) Indent(n1, "// scope calls 'eval'\n");
   if (scope_uses_arguments_) Indent(n1, "// scope uses 'arguments'\n");
   if (scope_uses_super_property_)
     Indent(n1, "// scope uses 'super' property\n");
   if (scope_uses_this_) Indent(n1, "// scope uses 'this'\n");
+  if (scope_uses_new_target_) Indent(n1, "// scope uses 'new.target'\n");
   if (inner_scope_uses_arguments_) {
     Indent(n1, "// inner scope uses 'arguments'\n");
   }
   if (inner_scope_uses_super_property_)
     Indent(n1, "// inner scope uses 'super' property\n");
   if (inner_scope_uses_this_) Indent(n1, "// inner scope uses 'this'\n");
+  if (inner_scope_uses_new_target_) {
+    Indent(n1, "// inner scope uses 'new.target'\n");
+  }
   if (outer_scope_calls_sloppy_eval_) {
     Indent(n1, "// outer scope calls 'eval' in sloppy context\n");
   }
   if (inner_scope_calls_eval_) Indent(n1, "// inner scope calls 'eval'\n");
   if (num_stack_slots_ > 0) { Indent(n1, "// ");
   PrintF("%d stack slots\n", num_stack_slots_); }
   if (num_heap_slots_ > 0) { Indent(n1, "// ");
   PrintF("%d heap slots\n", num_heap_slots_); }
 
   // Print locals.
@@ skipping 305 matching lines @@
       if (inner->scope_uses_arguments_ || inner->inner_scope_uses_arguments_) {
         inner_scope_uses_arguments_ = true;
       }
       if (inner->scope_uses_super_property_ ||
           inner->inner_scope_uses_super_property_) {
         inner_scope_uses_super_property_ = true;
       }
       if (inner->scope_uses_this_ || inner->inner_scope_uses_this_) {
         inner_scope_uses_this_ = true;
       }
+      if (inner->scope_uses_new_target_ ||
+          inner->inner_scope_uses_new_target_) {
+        inner_scope_uses_new_target_ = true;
+      }
     }
     if (inner->force_eager_compilation_) {
       force_eager_compilation_ = true;
     }
     if (asm_module_ && inner->scope_type() == FUNCTION_SCOPE) {
       inner->asm_function_ = true;
     }
   }
 }
 
@@ skipping 111 matching lines @@
           AllocateHeapSlot(var);
         }
       } else {
         DCHECK(var->IsUnallocated() || var->IsParameter());
         if (var->IsUnallocated()) {
           var->AllocateTo(Variable::PARAMETER, i);
         }
       }
     }
   }
+
+  Variable* new_target = LookupLocal(ast_value_factory_->new_target_string());
+  // Functions have 'new_target' declared implicitly in all non arrow functions.
+  DCHECK(new_target != nullptr || is_arrow_scope());
+
+  if (new_target != nullptr) {
+    if (IsSubclassConstructor(function_kind_)) {
+      new_target->ForceContextAllocation();
+      new_target_ = new_target;
+    } else if (MustAllocate(new_target)) {
+      new_target_ = new_target;
+    }
+  }
 }
 
 
 void Scope::AllocateNonParameterLocal(Isolate* isolate, Variable* var) {
   DCHECK(var->scope() == this);
   DCHECK(!var->IsVariable(isolate->factory()->dot_result_string()) ||
          !var->IsStackLocal());
   if (var->IsUnallocated() && MustAllocate(var)) {
     if (MustAllocateInContext(var)) {
       AllocateHeapSlot(var);
@@ skipping 98 matching lines @@
       (function_ != NULL && function_->proxy()->var()->IsStackLocal() ? 1 : 0);
 }
 
 
 int Scope::ContextLocalCount() const {
   if (num_heap_slots() == 0) return 0;
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS -
       (function_ != NULL && function_->proxy()->var()->IsContextSlot() ? 1 : 0);
 }
 } }  // namespace v8::internal