Reviewers: Mads Ager,
Description:
Make Empty function to have no prototype and use it as __proto__ for all
functions without prototype.
Please review this at http://codereview.chromium.org/1769013/show
SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/
Affected files:
M src/bootstrapper.cc
M test/mjsunit/unusual-constructor.js
Index: test/mjsunit/unusual-constructor.js
===================================================================
--- test/mjsunit/unusual-constructor.js (revision 4535)
+++ test/mjsunit/unusual-constructor.js (working copy)
@@ -25,12 +25,9 @@
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-var obj = new (Function.__proto__)();
-
-
var threw = false;
try {
- obj.toString();
+ var obj = new (Function.__proto__)();
} catch (e) {
assertInstanceof(e, TypeError);
threw = true;
Index: src/bootstrapper.cc
===================================================================
--- src/bootstrapper.cc (revision 4536)
+++ src/bootstrapper.cc (working copy)
@@ -418,12 +418,15 @@
// Functions with this map will not have a 'prototype' property, and
// can not be used as constructors.
- fm = Factory::NewMap(JS_FUNCTION_TYPE, JSFunction::kSize);
- global_context()->set_function_without_prototype_map(*fm);
- function_map_descriptors =
+ Handle<Map> function_without_prototype_map =
+ Factory::NewMap(JS_FUNCTION_TYPE, JSFunction::kSize);
+ global_context()->set_function_without_prototype_map(
+ *function_without_prototype_map);
+ Handle<DescriptorArray> function_without_prototype_map_descriptors =
ComputeFunctionInstanceDescriptor(DONT_ADD_PROTOTYPE);
- fm->set_instance_descriptors(*function_map_descriptors);
- fm->set_function_with_prototype(false);
+ function_without_prototype_map->set_instance_descriptors(
+ *function_without_prototype_map_descriptors);
+ function_without_prototype_map->set_function_with_prototype(false);
// Allocate the function map first and then patch the prototype later
fm = Factory::NewMap(JS_FUNCTION_TYPE, JSFunction::kSize);
@@ -459,7 +462,7 @@
// 262 15.3.4.
Handle<String> symbol = Factory::LookupAsciiSymbol("Empty");
Handle<JSFunction> empty_function =
- Factory::NewFunction(symbol, Factory::null_value());
+ Factory::NewFunctionWithoutPrototype(symbol);
// --- E m p t y ---
Handle<Code> code =
@@ -474,15 +477,14 @@
empty_function->shared()->DontAdaptArguments();
global_context()->function_map()->set_prototype(*empty_function);
global_context()->function_instance_map()->set_prototype(*empty_function);
+ global_context()->function_without_prototype_map()->
+ set_prototype(*empty_function);
- // Allocate a distinct prototype for the function map for functions
without
- // prototype, so it will not add 'prototype' property in the proto chain.
- global_context()->function_without_prototype_map()->set_prototype(
- *Factory::NewJSObject(Top::object_function(), TENURED));
-
// Allocate the function map first and then patch the prototype later
- Handle<Map> empty_fm = Factory::CopyMapDropDescriptors(fm);
- empty_fm->set_instance_descriptors(*function_map_descriptors);
+ Handle<Map> empty_fm = Factory::CopyMapDropDescriptors(
+ function_without_prototype_map);
+ empty_fm->set_instance_descriptors(
+ *function_without_prototype_map_descriptors);
empty_fm->set_prototype(global_context()->object_function()->prototype());
empty_function->set_map(*empty_fm);
return empty_function;
@@ -1258,23 +1260,6 @@
// Set the lengths for the functions to satisfy ECMA-262.
call->shared()->set_length(1);
apply->shared()->set_length(2);
-
- // Install the call, apply, toString and constructor properties
- // for the functions without prototype.
- Handle<JSObject> wp_proto = Handle<JSObject>(
-
JSObject::cast(Top::function_without_prototype_map()->prototype()));
-
- Handle<String> call_symbol = Factory::LookupAsciiSymbol("call");
- SetProperty(wp_proto, call_symbol, call, DONT_ENUM);
-
- Handle<String> apply_symbol = Factory::LookupAsciiSymbol("apply");
- SetProperty(wp_proto, apply_symbol, apply, DONT_ENUM);
-
- Handle<Object> to_string = GetProperty(proto, "toString");
- Handle<String> to_string_symbol =
Factory::LookupAsciiSymbol("toString");
- SetProperty(wp_proto, to_string_symbol, to_string, DONT_ENUM);
-
- SetProperty(wp_proto, Factory::constructor_symbol(), function,
DONT_ENUM);
}
// Create a constructor for RegExp results (a variant of Array that
--
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