Use a different map to distinguish eval contexts

src/runtime/runtime-scopes.cc

 // Copyright 2014 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/runtime/runtime-utils.h"
 
 #include <memory>
 
 #include "src/accessors.h"
 #include "src/arguments.h"
@@ skipping 214 matching lines @@
 Object* DeclareEvalHelper(Isolate* isolate, Handle<String> name,
                           Handle<Object> value) {
   // Declarations are always made in a function, native, or script context, or
   // a declaration block scope. Since this is called from eval, the context
   // passed is the context of the caller, which may be some nested context and
   // not the declaration context.
   Handle<Context> context_arg(isolate->context(), isolate);
   Handle<Context> context(context_arg->declaration_context(), isolate);
 
   DCHECK(context->IsFunctionContext() || context->IsNativeContext() ||
-         context->IsScriptContext() ||
+         context->IsScriptContext() || context->IsEvalContext() ||
          (context->IsBlockContext() && context->has_extension()));
 
   bool is_function = value->IsJSFunction();
   bool is_var = !is_function;
   DCHECK(!is_var || value->IsUndefined(isolate));
 
   int index;
   PropertyAttributes attributes;
   InitializationFlag init_flag;
   VariableMode mode;
@@ skipping 60 matching lines @@
       object = isolate->factory()->NewJSObject(
           isolate->context_extension_function());
       Handle<HeapObject> extension = isolate->factory()->NewContextExtension(
           handle(context->scope_info()), object);
       context->set_extension(*extension);
     } else {
       object = handle(context->extension_object(), isolate);
     }
     DCHECK(object->IsJSContextExtensionObject() || object->IsJSGlobalObject());
   } else {
-    DCHECK(context->IsFunctionContext());
+    DCHECK(context->IsFunctionContext() || context->IsEvalContext());

[adamk, 2016/11/12 00:26:05]

We should never get here for an eval context, since a sloppy eval context never
gets an extension object.

[Dan Ehrenberg, 2016/12/07 05:41:26]

Reverted and added a comment explaining the DCHECK.

     object =
         isolate->factory()->NewJSObject(isolate->context_extension_function());
     context->set_extension(*object);
   }
 
   RETURN_FAILURE_ON_EXCEPTION(isolate, JSObject::SetOwnPropertyIgnoreAttributes(
                                            object, name, value, NONE));
 
   return isolate->heap()->undefined_value();
 }
@@ skipping 362 matching lines @@
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
 
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
 
   DCHECK(function->context() == isolate->context());
   int length = function->shared()->scope_info()->ContextLength();
   return *isolate->factory()->NewFunctionContext(length, function);
 }
 
+RUNTIME_FUNCTION(Runtime_NewEvalContext) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+
+  CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
+
+  DCHECK(function->context() == isolate->context());
+  int length = function->shared()->scope_info()->ContextLength();
+  return *isolate->factory()->NewEvalContext(length, function);
+}
 
 RUNTIME_FUNCTION(Runtime_PushWithContext) {
   HandleScope scope(isolate);
   DCHECK_EQ(3, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSReceiver, extension_object, 0);
   CONVERT_ARG_HANDLE_CHECKED(ScopeInfo, scope_info, 1);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 2);
   Handle<Context> current(isolate->context());
   Handle<Context> context = isolate->factory()->NewWithContext(
       function, current, scope_info, extension_object);
@@ skipping 247 matching lines @@
 RUNTIME_FUNCTION(Runtime_StoreLookupSlot_Strict) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
   CONVERT_ARG_HANDLE_CHECKED(String, name, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, value, 1);
   RETURN_RESULT_OR_FAILURE(isolate, StoreLookupSlot(name, value, STRICT));
 }
 
 }  // namespace internal
 }  // namespace v8