Cleaned up runtime macros a bit.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 8a0915c894dba7b98c9a0cd0c35918220468cb2d..f2da681d08cf593f1580027172db09bfbbe48a84 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -69,9 +69,9 @@ namespace internal {
 // Cast the given object to a value of the specified type and store
 // it in a variable with the given name.  If the object is not of the
 // expected type call IllegalOperation and return.
-#define CONVERT_CHECKED(Type, name, obj)                             \
-  RUNTIME_ASSERT(obj->Is##Type());                                   \
-  Type* name = Type::cast(obj);
+#define CONVERT_CHECKED(Type, name, index)                           \

[Jakob Kummerow, 2012/02/20 17:31:47]

Now that there's so little difference between CONVERT_CHECKED and
CONVERT_ARG_CHECKED (and you wouldn't guess *what* the difference is from the
macros' names!), have you thought about (1) merging or (2) renaming them?

(1) would effectively mean to handlify most of this file.

A suggestion for (2) would be:
CONVERT_CHECKED -> CONVERT_ARG_CHECKED
CONVERT_ARG_CHECKED -> CONVERT_ARG_HANDLE_CHECKED

[Sven Panne, 2012/02/21 07:21:01]

I am not 100% sure if we can really handlify everything here (probably yes, but
we need e.g. Object::IsObject, too, which shouldn't be too hard to implement
;-), so I left both macros. Merging them can be done in a separate CL, so I'll
follow your renaming proposal for now.

+  RUNTIME_ASSERT(args[index]->Is##Type());                           \
+  Type* name = Type::cast(args[index]);
 
 #define CONVERT_ARG_CHECKED(Type, name, index)                       \
   RUNTIME_ASSERT(args[index]->Is##Type());                           \
@@ -80,9 +80,9 @@ namespace internal {
 // Cast the given object to a boolean and store it in a variable with
 // the given name.  If the object is not a boolean call IllegalOperation
 // and return.
-#define CONVERT_BOOLEAN_CHECKED(name, obj)                            \
-  RUNTIME_ASSERT(obj->IsBoolean());                                   \
-  bool name = (obj)->IsTrue();
+#define CONVERT_BOOLEAN_CHECKED(name, index)                         \
+  RUNTIME_ASSERT(args[index]->IsBoolean());                          \
+  bool name = args[index]->IsTrue();
 
 // Cast the given argument to a Smi and store its value in an int variable
 // with the given name.  If the argument is not a Smi call IllegalOperation
@@ -106,12 +106,20 @@ namespace internal {
   type name = NumberTo##Type(obj);
 
 
+// Cast the given argument to PropertyDetails and store its value in a
+// variable with the given name.  If the argument is not a Smi call
+// IllegalOperation and return.
+#define CONVERT_PROPERTY_DETAILS_CHECKED(name, index)                \
+  RUNTIME_ASSERT(args[index]->IsSmi());                              \
+  PropertyDetails name = PropertyDetails(Smi::cast(args[index]));
+
+
 // Assert that the given argument has a valid value for a StrictModeFlag
 // and store it in a StrictModeFlag variable with the given name.
 #define CONVERT_STRICT_MODE_ARG(name, index)                         \
-  ASSERT(args[index]->IsSmi());                                      \
-  ASSERT(args.smi_at(index) == kStrictMode ||                        \
-         args.smi_at(index) == kNonStrictMode);                      \
+  RUNTIME_ASSERT(args[index]->IsSmi());                              \
+  RUNTIME_ASSERT(args.smi_at(index) == kStrictMode ||                \
+                 args.smi_at(index) == kNonStrictMode);              \
   StrictModeFlag name =                                              \
       static_cast<StrictModeFlag>(args.smi_at(index));
 
@@ -691,28 +699,28 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_IsJSFunctionProxy) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetHandler) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSProxy, proxy, args[0]);
+  CONVERT_CHECKED(JSProxy, proxy, 0);
   return proxy->handler();
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetCallTrap) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSFunctionProxy, proxy, args[0]);
+  CONVERT_CHECKED(JSFunctionProxy, proxy, 0);
   return proxy->call_trap();
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetConstructTrap) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSFunctionProxy, proxy, args[0]);
+  CONVERT_CHECKED(JSFunctionProxy, proxy, 0);
   return proxy->construct_trap();
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_Fix) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSProxy, proxy, args[0]);
+  CONVERT_CHECKED(JSProxy, proxy, 0);
   proxy->Fix();
   return isolate->heap()->undefined_value();
 }
@@ -840,7 +848,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ClassOf) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetPrototype) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSReceiver, input_obj, args[0]);
+  CONVERT_CHECKED(JSReceiver, input_obj, 0);
   Object* obj = input_obj;
   // We don't expect access checks to be needed on JSProxy objects.
   ASSERT(!obj->IsAccessCheckNeeded() || obj->IsJSObject());
@@ -1147,14 +1155,14 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetOwnProperty) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_PreventExtensions) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSObject, obj, args[0]);
+  CONVERT_CHECKED(JSObject, obj, 0);
   return obj->PreventExtensions();
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_IsExtensible) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSObject, obj, args[0]);
+  CONVERT_CHECKED(JSObject, obj, 0);
   if (obj->IsJSGlobalProxy()) {
     Object* proto = obj->GetPrototype();
     if (proto->IsNull()) return isolate->heap()->false_value();
@@ -1195,9 +1203,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_IsTemplate) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetTemplateField) {
   ASSERT(args.length() == 2);
-  CONVERT_CHECKED(HeapObject, templ, args[0]);
-  CONVERT_CHECKED(Smi, field, args[1]);
-  int index = field->value();
+  CONVERT_CHECKED(HeapObject, templ, 0);
+  CONVERT_SMI_ARG_CHECKED(index, 1)
   int offset = index * kPointerSize + HeapObject::kHeaderSize;
   InstanceType type = templ->map()->instance_type();
   RUNTIME_ASSERT(type ==  FUNCTION_TEMPLATE_INFO_TYPE ||
@@ -1214,7 +1221,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetTemplateField) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DisableAccessChecks) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(HeapObject, object, args[0]);
+  CONVERT_CHECKED(HeapObject, object, 0);
   Map* old_map = object->map();
   bool needs_access_checks = old_map->is_access_check_needed();
   if (needs_access_checks) {
@@ -1233,7 +1240,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DisableAccessChecks) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_EnableAccessChecks) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(HeapObject, object, args[0]);
+  CONVERT_CHECKED(HeapObject, object, 0);
   Map* old_map = object->map();
   if (!old_map->is_access_check_needed()) {
     // Copy map so it won't interfere constructor's initial map.
@@ -1769,8 +1776,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_RegExpConstructResult) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_RegExpInitializeObject) {
   AssertNoAllocation no_alloc;
   ASSERT(args.length() == 5);
-  CONVERT_CHECKED(JSRegExp, regexp, args[0]);
-  CONVERT_CHECKED(String, source, args[1]);
+  CONVERT_CHECKED(JSRegExp, regexp, 0);
+  CONVERT_CHECKED(String, source, 1);
 
   Object* global = args[2];
   if (!global->IsTrue()) global = isolate->heap()->false_value();
@@ -1883,7 +1890,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_SpecialArrayFunctions) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetDefaultReceiver) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSReceiver, callable, args[0]);
+  CONVERT_CHECKED(JSReceiver, callable, 0);
 
   if (!callable->IsJSFunction()) {
     HandleScope scope(isolate);
@@ -1942,7 +1949,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionGetName) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSFunction, f, args[0]);
+  CONVERT_CHECKED(JSFunction, f, 0);
   return f->shared()->name();
 }
 
@@ -1951,8 +1958,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionSetName) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
-  CONVERT_CHECKED(JSFunction, f, args[0]);
-  CONVERT_CHECKED(String, name, args[1]);
+  CONVERT_CHECKED(JSFunction, f, 0);
+  CONVERT_CHECKED(String, name, 1);
   f->shared()->set_name(name);
   return isolate->heap()->undefined_value();
 }
@@ -1961,7 +1968,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionSetName) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionNameShouldPrintAsAnonymous) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSFunction, f, args[0]);
+  CONVERT_CHECKED(JSFunction, f, 0);
   return isolate->heap()->ToBoolean(
       f->shared()->name_should_print_as_anonymous());
 }
@@ -1970,7 +1977,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionNameShouldPrintAsAnonymous) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionMarkNameShouldPrintAsAnonymous) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSFunction, f, args[0]);
+  CONVERT_CHECKED(JSFunction, f, 0);
   f->shared()->set_name_should_print_as_anonymous(true);
   return isolate->heap()->undefined_value();
 }
@@ -1980,7 +1987,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionRemovePrototype) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSFunction, f, args[0]);
+  CONVERT_CHECKED(JSFunction, f, 0);
   Object* obj = f->RemovePrototype();
   if (obj->IsFailure()) return obj;
 
@@ -1992,7 +1999,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionGetScript) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSFunction, fun, args[0]);
+  CONVERT_CHECKED(JSFunction, fun, 0);
   Handle<Object> script = Handle<Object>(fun->shared()->script(), isolate);
   if (!script->IsScript()) return isolate->heap()->undefined_value();
 
@@ -2014,7 +2021,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionGetScriptSourcePosition) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSFunction, fun, args[0]);
+  CONVERT_CHECKED(JSFunction, fun, 0);
   int pos = fun->shared()->start_position();
   return Smi::FromInt(pos);
 }
@@ -2023,7 +2030,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionGetScriptSourcePosition) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionGetPositionForOffset) {
   ASSERT(args.length() == 2);
 
-  CONVERT_CHECKED(Code, code, args[0]);
+  CONVERT_CHECKED(Code, code, 0);
   CONVERT_NUMBER_CHECKED(int, offset, Int32, args[1]);
 
   RUNTIME_ASSERT(0 <= offset && offset < code->Size());
@@ -2037,8 +2044,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionSetInstanceClassName) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
-  CONVERT_CHECKED(JSFunction, fun, args[0]);
-  CONVERT_CHECKED(String, name, args[1]);
+  CONVERT_CHECKED(JSFunction, fun, 0);
+  CONVERT_CHECKED(String, name, 1);
   fun->SetInstanceClassName(name);
   return isolate->heap()->undefined_value();
 }
@@ -2048,10 +2055,10 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionSetLength) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
-  CONVERT_CHECKED(JSFunction, fun, args[0]);
-  CONVERT_CHECKED(Smi, length, args[1]);
-  fun->shared()->set_length(length->value());
-  return length;
+  CONVERT_CHECKED(JSFunction, fun, 0);
+  CONVERT_SMI_ARG_CHECKED(length, 1);
+  fun->shared()->set_length(length);
+  return fun;

[Jakob Kummerow, 2012/02/20 17:31:47]

Is this change intentional?

[Sven Panne, 2012/02/21 07:21:01]

Yep, it is just our usual ultra-confusing way of signaling "OK". Thinking about
it, I'll replace it with undefined to make it a bit clearer.

 }
 
 
@@ -2059,7 +2066,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionSetPrototype) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
-  CONVERT_CHECKED(JSFunction, fun, args[0]);
+  CONVERT_CHECKED(JSFunction, fun, 0);
   ASSERT(fun->should_have_prototype());
   Object* obj;
   { MaybeObject* maybe_obj =
@@ -2073,7 +2080,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionSetPrototype) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionSetReadOnlyPrototype) {
   NoHandleAllocation ha;
   RUNTIME_ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSFunction, function, args[0]);
+  CONVERT_CHECKED(JSFunction, function, 0);
 
   MaybeObject* maybe_name =
       isolate->heap()->AllocateStringFromAscii(CStrVector("prototype"));
@@ -2129,7 +2136,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionIsAPIFunction) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSFunction, f, args[0]);
+  CONVERT_CHECKED(JSFunction, f, 0);
   return isolate->heap()->ToBoolean(f->shared()->IsApiFunction());
 }
 
@@ -2138,7 +2145,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionIsBuiltin) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSFunction, f, args[0]);
+  CONVERT_CHECKED(JSFunction, f, 0);
   return isolate->heap()->ToBoolean(f->IsBuiltin());
 }
 
@@ -2235,7 +2242,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringCharCodeAt) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
-  CONVERT_CHECKED(String, subject, args[0]);
+  CONVERT_CHECKED(String, subject, 0);
   Object* index = args[1];
   RUNTIME_ASSERT(index->IsNumber());
 
@@ -3212,7 +3219,7 @@ MUST_USE_RESULT static MaybeObject* StringReplaceRegExpWithEmptyString(
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringReplaceRegExpWithString) {
   ASSERT(args.length() == 4);
 
-  CONVERT_CHECKED(String, subject, args[0]);
+  CONVERT_CHECKED(String, subject, 0);
   if (!subject->IsFlat()) {
     Object* flat_subject;
     { MaybeObject* maybe_flat_subject = subject->TryFlatten();
@@ -3223,7 +3230,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringReplaceRegExpWithString) {
     subject = String::cast(flat_subject);
   }
 
-  CONVERT_CHECKED(String, replacement, args[2]);
+  CONVERT_CHECKED(String, replacement, 2);
   if (!replacement->IsFlat()) {
     Object* flat_replacement;
     { MaybeObject* maybe_flat_replacement = replacement->TryFlatten();
@@ -3234,8 +3241,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringReplaceRegExpWithString) {
     replacement = String::cast(flat_replacement);
   }
 
-  CONVERT_CHECKED(JSRegExp, regexp, args[1]);
-  CONVERT_CHECKED(JSArray, last_match_info, args[3]);
+  CONVERT_CHECKED(JSRegExp, regexp, 1);
+  CONVERT_CHECKED(JSArray, last_match_info, 3);
 
   ASSERT(last_match_info->HasFastElements());
 
@@ -3497,8 +3504,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringLocaleCompare) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
-  CONVERT_CHECKED(String, str1, args[0]);
-  CONVERT_CHECKED(String, str2, args[1]);
+  CONVERT_CHECKED(String, str1, 0);
+  CONVERT_CHECKED(String, str2, 1);
 
   if (str1 == str2) return Smi::FromInt(0);  // Equal.
   int str1_length = str1->length();
@@ -3545,7 +3552,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_SubString) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 3);
 
-  CONVERT_CHECKED(String, value, args[0]);
+  CONVERT_CHECKED(String, value, 0);
   int start, end;
   // We have a fast integer-only case here to avoid a conversion to double in
   // the common case where from and to are Smis.
@@ -4318,18 +4325,17 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DefineOrRedefineAccessorProperty) {
   ASSERT(args.length() == 5);
   HandleScope scope(isolate);
   CONVERT_ARG_CHECKED(JSObject, obj, 0);
-  CONVERT_CHECKED(String, name, args[1]);
-  CONVERT_CHECKED(Smi, flag_setter, args[2]);
+  CONVERT_CHECKED(String, name, 1);
+  CONVERT_SMI_ARG_CHECKED(flag_setter, 2);
   Object* fun = args[3];
-  CONVERT_CHECKED(Smi, flag_attr, args[4]);
+  CONVERT_SMI_ARG_CHECKED(unchecked, 4);
 
-  int unchecked = flag_attr->value();
   RUNTIME_ASSERT((unchecked & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
   PropertyAttributes attr = static_cast<PropertyAttributes>(unchecked);
 
   RUNTIME_ASSERT(!obj->IsNull());
   RUNTIME_ASSERT(fun->IsSpecFunction() || fun->IsUndefined());
-  return obj->DefineAccessor(name, flag_setter->value() == 0, fun, attr);
+  return obj->DefineAccessor(name, flag_setter == 0, fun, attr);
 }
 
 // Implements part of 8.12.9 DefineOwnProperty.
@@ -4344,9 +4350,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DefineOrRedefineDataProperty) {
   CONVERT_ARG_CHECKED(JSObject, js_object, 0);
   CONVERT_ARG_CHECKED(String, name, 1);
   Handle<Object> obj_value = args.at<Object>(2);
-  CONVERT_CHECKED(Smi, flag, args[3]);
+  CONVERT_SMI_ARG_CHECKED(unchecked, 3);
 
-  int unchecked = flag->value();
   RUNTIME_ASSERT((unchecked & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
   PropertyAttributes attr = static_cast<PropertyAttributes>(unchecked);
 
@@ -4758,13 +4763,12 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StoreArrayLiteralElement) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_IgnoreAttributesAndSetProperty) {
   NoHandleAllocation ha;
   RUNTIME_ASSERT(args.length() == 3 || args.length() == 4);
-  CONVERT_CHECKED(JSObject, object, args[0]);
-  CONVERT_CHECKED(String, name, args[1]);
+  CONVERT_CHECKED(JSObject, object, 0);
+  CONVERT_CHECKED(String, name, 1);
   // Compute attributes.
   PropertyAttributes attributes = NONE;
   if (args.length() == 4) {
-    CONVERT_CHECKED(Smi, value_obj, args[3]);
-    int unchecked_value = value_obj->value();
+    CONVERT_SMI_ARG_CHECKED(unchecked_value, 3);
     // Only attribute bits should be set.
     RUNTIME_ASSERT(
         (unchecked_value & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
@@ -4780,8 +4784,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DeleteProperty) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 3);
 
-  CONVERT_CHECKED(JSReceiver, object, args[0]);
-  CONVERT_CHECKED(String, key, args[1]);
+  CONVERT_CHECKED(JSReceiver, object, 0);
+  CONVERT_CHECKED(String, key, 1);
   CONVERT_STRICT_MODE_ARG(strict_mode, 2);
   return object->DeleteProperty(key, (strict_mode == kStrictMode)
                                       ? JSReceiver::STRICT_DELETION
@@ -4810,7 +4814,7 @@ static Object* HasLocalPropertyImplementation(Isolate* isolate,
 RUNTIME_FUNCTION(MaybeObject*, Runtime_HasLocalProperty) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
-  CONVERT_CHECKED(String, key, args[1]);
+  CONVERT_CHECKED(String, key, 1);
 
   uint32_t index;
   const bool key_is_array_index = key->AsArrayIndex(&index);
@@ -4848,8 +4852,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_HasLocalProperty) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_HasProperty) {
   NoHandleAllocation na;
   ASSERT(args.length() == 2);
-  CONVERT_CHECKED(JSReceiver, receiver, args[0]);
-  CONVERT_CHECKED(String, key, args[1]);
+  CONVERT_CHECKED(JSReceiver, receiver, 0);
+  CONVERT_CHECKED(String, key, 1);
 
   bool result = receiver->HasProperty(key);
   if (isolate->has_pending_exception()) return Failure::Exception();
@@ -4860,10 +4864,10 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_HasProperty) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_HasElement) {
   NoHandleAllocation na;
   ASSERT(args.length() == 2);
-  CONVERT_CHECKED(JSReceiver, receiver, args[0]);
-  CONVERT_CHECKED(Smi, index, args[1]);
+  CONVERT_CHECKED(JSReceiver, receiver, 0);
+  CONVERT_SMI_ARG_CHECKED(index, 1);
 
-  bool result = receiver->HasElement(index->value());
+  bool result = receiver->HasElement(index);
   if (isolate->has_pending_exception()) return Failure::Exception();
   return isolate->heap()->ToBoolean(result);
 }
@@ -4873,8 +4877,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_IsPropertyEnumerable) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
-  CONVERT_CHECKED(JSObject, object, args[0]);
-  CONVERT_CHECKED(String, key, args[1]);
+  CONVERT_CHECKED(JSObject, object, 0);
+  CONVERT_CHECKED(String, key, 1);
 
   uint32_t index;
   if (key->AsArrayIndex(&index)) {
@@ -4935,7 +4939,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetPropertyNames) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetPropertyNamesFast) {
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSReceiver, raw_object, args[0]);
+  CONVERT_CHECKED(JSReceiver, raw_object, 0);
 
   if (raw_object->IsSimpleEnum()) return raw_object->map();
 
@@ -5122,7 +5126,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetIndexedInterceptorElementNames) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_LocalKeys) {
   ASSERT_EQ(args.length(), 1);
-  CONVERT_CHECKED(JSObject, raw_object, args[0]);
+  CONVERT_CHECKED(JSObject, raw_object, 0);
   HandleScope scope(isolate);
   Handle<JSObject> object(raw_object);
 
@@ -5314,7 +5318,7 @@ static int ParseDecimalInteger(const char*s, int from, int to) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringToNumber) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(String, subject, args[0]);
+  CONVERT_CHECKED(String, subject, 0);
   subject->TryFlatten();
 
   // Fast case: short integer or some sorts of junk values.
@@ -5370,7 +5374,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringFromCharCodeArray) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSArray, codes, args[0]);
+  CONVERT_CHECKED(JSArray, codes, 0);
   int length = Smi::cast(codes->length())->value();
 
   // Check if the string can be ASCII.
@@ -5450,7 +5454,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_URIEscape) {
   const char hex_chars[] = "0123456789ABCDEF";
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(String, source, args[0]);
+  CONVERT_CHECKED(String, source, 0);
 
   source->TryFlatten();
 
@@ -5568,7 +5572,7 @@ static inline int Unescape(String* source,
 RUNTIME_FUNCTION(MaybeObject*, Runtime_URIUnescape) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(String, source, args[0]);
+  CONVERT_CHECKED(String, source, 0);
 
   source->TryFlatten();
 
@@ -5825,7 +5829,7 @@ static MaybeObject* QuoteJsonString(Isolate* isolate,
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_QuoteJSONString) {
   NoHandleAllocation ha;
-  CONVERT_CHECKED(String, str, args[0]);
+  CONVERT_CHECKED(String, str, 0);
   if (!str->IsFlat()) {
     MaybeObject* try_flatten = str->TryFlatten();
     Object* flat;
@@ -5849,7 +5853,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_QuoteJSONString) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_QuoteJSONStringComma) {
   NoHandleAllocation ha;
-  CONVERT_CHECKED(String, str, args[0]);
+  CONVERT_CHECKED(String, str, 0);
   if (!str->IsFlat()) {
     MaybeObject* try_flatten = str->TryFlatten();
     Object* flat;
@@ -5926,7 +5930,7 @@ static MaybeObject* QuoteJsonStringArray(Isolate* isolate,
 RUNTIME_FUNCTION(MaybeObject*, Runtime_QuoteJSONStringArray) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSArray, array, args[0]);
+  CONVERT_CHECKED(JSArray, array, 0);
 
   if (!array->HasFastElements()) return isolate->heap()->undefined_value();
   FixedArray* elements = FixedArray::cast(array->elements());
@@ -5968,7 +5972,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_QuoteJSONStringArray) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringParseInt) {
   NoHandleAllocation ha;
 
-  CONVERT_CHECKED(String, s, args[0]);
+  CONVERT_CHECKED(String, s, 0);
   CONVERT_SMI_ARG_CHECKED(radix, 1);
 
   s->TryFlatten();
@@ -5981,7 +5985,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringParseInt) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringParseFloat) {
   NoHandleAllocation ha;
-  CONVERT_CHECKED(String, str, args[0]);
+  CONVERT_CHECKED(String, str, 0);
 
   // ECMA-262 section 15.1.2.3, empty string is NaN
   double value = StringToDouble(isolate->unicode_cache(),
@@ -6230,7 +6234,7 @@ MUST_USE_RESULT static MaybeObject* ConvertCase(
     Isolate* isolate,
     unibrow::Mapping<typename ConvertTraits::UnibrowConverter, 128>* mapping) {
   NoHandleAllocation ha;
-  CONVERT_CHECKED(String, s, args[0]);
+  CONVERT_CHECKED(String, s, 0);
   s = s->TryFlattenGetString();
 
   const int length = s->length();
@@ -6292,9 +6296,9 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringTrim) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 3);
 
-  CONVERT_CHECKED(String, s, args[0]);
-  CONVERT_BOOLEAN_CHECKED(trimLeft, args[1]);
-  CONVERT_BOOLEAN_CHECKED(trimRight, args[2]);
+  CONVERT_CHECKED(String, s, 0);
+  CONVERT_BOOLEAN_CHECKED(trimLeft, 1);
+  CONVERT_BOOLEAN_CHECKED(trimRight, 2);
 
   s->TryFlatten();
   int length = s->length();
@@ -6492,7 +6496,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringToArray) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_NewStringWrapper) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(String, value, args[0]);
+  CONVERT_CHECKED(String, value, 0);
   return value->ToObject();
 }
 
@@ -6683,8 +6687,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_NumberMod) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringAdd) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
-  CONVERT_CHECKED(String, str1, args[0]);
-  CONVERT_CHECKED(String, str2, args[1]);
+  CONVERT_CHECKED(String, str1, 0);
+  CONVERT_CHECKED(String, str2, 1);
   isolate->counters()->string_add_runtime()->Increment();
   return isolate->heap()->AllocateConsString(str1, str2);
 }
@@ -6732,13 +6736,13 @@ static inline void StringBuilderConcatHelper(String* special,
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringBuilderConcat) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 3);
-  CONVERT_CHECKED(JSArray, array, args[0]);
+  CONVERT_CHECKED(JSArray, array, 0);
   if (!args[1]->IsSmi()) {
     isolate->context()->mark_out_of_memory();
     return Failure::OutOfMemoryException();
   }
   int array_length = args.smi_at(1);
-  CONVERT_CHECKED(String, special, args[2]);
+  CONVERT_CHECKED(String, special, 2);
 
   // This assumption is used by the slice encoding in one or two smis.
   ASSERT(Smi::kMaxValue >= String::kMaxLength);
@@ -6848,13 +6852,13 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringBuilderConcat) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringBuilderJoin) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 3);
-  CONVERT_CHECKED(JSArray, array, args[0]);
+  CONVERT_CHECKED(JSArray, array, 0);
   if (!args[1]->IsSmi()) {
     isolate->context()->mark_out_of_memory();
     return Failure::OutOfMemoryException();
   }
   int array_length = args.smi_at(1);
-  CONVERT_CHECKED(String, separator, args[2]);
+  CONVERT_CHECKED(String, separator, 2);
 
   if (!array->HasFastElements()) {
     return isolate->Throw(isolate->heap()->illegal_argument_symbol());
@@ -6972,11 +6976,11 @@ static void JoinSparseArrayWithSeparator(FixedArray* elements,
 RUNTIME_FUNCTION(MaybeObject*, Runtime_SparseJoinWithSeparator) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 3);
-  CONVERT_CHECKED(JSArray, elements_array, args[0]);
+  CONVERT_CHECKED(JSArray, elements_array, 0);
   RUNTIME_ASSERT(elements_array->HasFastElements() ||
                  elements_array->HasFastSmiOnlyElements());
   CONVERT_NUMBER_CHECKED(uint32_t, array_length, Uint32, args[1]);
-  CONVERT_CHECKED(String, separator, args[2]);
+  CONVERT_CHECKED(String, separator, 2);
   // elements_array is fast-mode JSarray of alternating positions
   // (increasing order) and strings.
   // array_length is length of original array (used to add separators);
@@ -6998,7 +7002,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_SparseJoinWithSeparator) {
   FixedArray* elements = FixedArray::cast(elements_array->elements());
   for (int i = 0; i < elements_length; i += 2) {
     RUNTIME_ASSERT(elements->get(i)->IsNumber());
-    CONVERT_CHECKED(String, string, elements->get(i + 1));
+    RUNTIME_ASSERT(elements->get(i + 1)->IsString());
+    String* string = String::cast(elements->get(i + 1));
     int length = string->length();
     if (is_ascii && !string->IsAsciiRepresentation()) {
       is_ascii = false;
@@ -7156,8 +7161,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringEquals) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
-  CONVERT_CHECKED(String, x, args[0]);
-  CONVERT_CHECKED(String, y, args[1]);
+  CONVERT_CHECKED(String, x, 0);
+  CONVERT_CHECKED(String, y, 1);
 
   bool not_equal = !x->Equals(y);
   // This is slightly convoluted because the value that signifies
@@ -7188,12 +7193,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_NumberCompare) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_SmiLexicographicCompare) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
-
-  // Extract the integer values from the Smis.
-  CONVERT_CHECKED(Smi, x, args[0]);
-  CONVERT_CHECKED(Smi, y, args[1]);
-  int x_value = x->value();
-  int y_value = y->value();
+  CONVERT_SMI_ARG_CHECKED(x_value, 0);
+  CONVERT_SMI_ARG_CHECKED(y_value, 1);
 
   // If the integers are equal so are the string representations.
   if (x_value == y_value) return Smi::FromInt(EQUAL);
@@ -7333,8 +7334,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_StringCompare) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
-  CONVERT_CHECKED(String, x, args[0]);
-  CONVERT_CHECKED(String, y, args[1]);
+  CONVERT_CHECKED(String, x, 0);
+  CONVERT_CHECKED(String, y, 1);
 
   isolate->counters()->string_compare_runtime()->Increment();
 
@@ -7941,7 +7942,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DateYMDFromTime) {
   ASSERT(args.length() == 2);
 
   CONVERT_DOUBLE_ARG_CHECKED(t, 0);
-  CONVERT_CHECKED(JSArray, res_array, args[1]);
+  CONVERT_CHECKED(JSArray, res_array, 1);
 
   int year, month, day;
   DateYMDFromTime(static_cast<int>(floor(t / 86400000)), year, month, day);
@@ -8098,7 +8099,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_NewClosure) {
   ASSERT(args.length() == 3);
   CONVERT_ARG_CHECKED(Context, context, 0);
   CONVERT_ARG_CHECKED(SharedFunctionInfo, shared, 1);
-  CONVERT_BOOLEAN_CHECKED(pretenure, args[2]);
+  CONVERT_BOOLEAN_CHECKED(pretenure, 2);
 
   // The caller ensures that we pretenure closures that are assigned
   // directly to properties.
@@ -8754,9 +8755,9 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_CheckIsBootstrapping) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_Call) {
   HandleScope scope(isolate);
   ASSERT(args.length() >= 2);
-  CONVERT_CHECKED(JSReceiver, fun, args[args.length() - 1]);
-  Object* receiver = args[0];
   int argc = args.length() - 2;
+  CONVERT_CHECKED(JSReceiver, fun, argc + 1);
+  Object* receiver = args[0];
 
   // If there are too many arguments, allocate argv via malloc.
   const int argv_small_size = 10;
@@ -8842,7 +8843,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_NewFunctionContext) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSFunction, function, args[0]);
+  CONVERT_CHECKED(JSFunction, function, 0);
   int length = function->shared()->scope_info()->ContextLength();
   Object* result;
   { MaybeObject* maybe_result =
@@ -9624,8 +9625,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_AllocateInNewSpace) {
 // false otherwise.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_PushIfAbsent) {
   ASSERT(args.length() == 2);
-  CONVERT_CHECKED(JSArray, array, args[0]);
-  CONVERT_CHECKED(JSObject, element, args[1]);
+  CONVERT_CHECKED(JSArray, array, 0);
+  CONVERT_CHECKED(JSObject, element, 1);
   RUNTIME_ASSERT(array->HasFastElements() || array->HasFastSmiOnlyElements());
   int length = Smi::cast(array->length())->value();
   FixedArray* elements = FixedArray::cast(array->elements());
@@ -10211,7 +10212,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GlobalPrint) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(String, string, args[0]);
+  CONVERT_CHECKED(String, string, 0);
   StringInputBuffer buffer(string);
   while (buffer.has_more()) {
     uint16_t character = buffer.GetNext();
@@ -10227,7 +10228,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GlobalPrint) {
 // Returns the number of non-undefined elements collected.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_RemoveArrayHoles) {
   ASSERT(args.length() == 2);
-  CONVERT_CHECKED(JSObject, object, args[0]);
+  CONVERT_CHECKED(JSObject, object, 0);
   CONVERT_NUMBER_CHECKED(uint32_t, limit, Uint32, args[1]);
   return object->PrepareElementsForSort(limit);
 }
@@ -10236,8 +10237,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_RemoveArrayHoles) {
 // Move contents of argument 0 (an array) to argument 1 (an array)
 RUNTIME_FUNCTION(MaybeObject*, Runtime_MoveArrayContents) {
   ASSERT(args.length() == 2);
-  CONVERT_CHECKED(JSArray, from, args[0]);
-  CONVERT_CHECKED(JSArray, to, args[1]);
+  CONVERT_CHECKED(JSArray, from, 0);
+  CONVERT_CHECKED(JSArray, to, 1);
   FixedArrayBase* new_elements = from->elements();
   MaybeObject* maybe_new_map;
   ElementsKind elements_kind;
@@ -10268,7 +10269,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_MoveArrayContents) {
 // How many elements does this object/array have?
 RUNTIME_FUNCTION(MaybeObject*, Runtime_EstimateNumberOfElements) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(JSObject, object, args[0]);
+  CONVERT_CHECKED(JSObject, object, 0);
   HeapObject* elements = object->elements();
   if (elements->IsDictionary()) {
     int result = SeededNumberDictionary::cast(elements)->NumberOfElements();
@@ -10368,27 +10369,26 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DefineAccessor) {
   // Compute attributes.
   PropertyAttributes attributes = NONE;
   if (args.length() == 5) {
-    CONVERT_CHECKED(Smi, attrs, args[4]);
-    int value = attrs->value();
+    CONVERT_SMI_ARG_CHECKED(value, 4);
     // Only attribute bits should be set.
     ASSERT((value & ~(READ_ONLY | DONT_ENUM | DONT_DELETE)) == 0);
     attributes = static_cast<PropertyAttributes>(value);
   }
 
-  CONVERT_CHECKED(JSObject, obj, args[0]);
-  CONVERT_CHECKED(String, name, args[1]);
-  CONVERT_CHECKED(Smi, flag, args[2]);
-  CONVERT_CHECKED(JSFunction, fun, args[3]);
-  return obj->DefineAccessor(name, flag->value() == 0, fun, attributes);
+  CONVERT_CHECKED(JSObject, obj, 0);
+  CONVERT_CHECKED(String, name, 1);
+  CONVERT_SMI_ARG_CHECKED(flag, 2);
+  CONVERT_CHECKED(JSFunction, fun, 3);
+  return obj->DefineAccessor(name, flag == 0, fun, attributes);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_LookupAccessor) {
   ASSERT(args.length() == 3);
-  CONVERT_CHECKED(JSObject, obj, args[0]);
-  CONVERT_CHECKED(String, name, args[1]);
-  CONVERT_CHECKED(Smi, flag, args[2]);
-  return obj->LookupAccessor(name, flag->value() == 0);
+  CONVERT_CHECKED(JSObject, obj, 0);
+  CONVERT_CHECKED(String, name, 1);
+  CONVERT_SMI_ARG_CHECKED(flag, 2);
+  return obj->LookupAccessor(name, flag == 0);
 }
 
 
@@ -10406,8 +10406,8 @@ static Smi* WrapFrameId(StackFrame::Id id) {
 }
 
 
-static StackFrame::Id UnwrapFrameId(Smi* wrapped) {
-  return static_cast<StackFrame::Id>(wrapped->value() << 2);
+static StackFrame::Id UnwrapFrameId(int wrapped) {
+  return static_cast<StackFrame::Id>(wrapped << 2);
 }
 
 
@@ -10624,9 +10624,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugGetProperty) {
 // args[0]: smi with property details.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugPropertyTypeFromDetails) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(Smi, details, args[0]);
-  PropertyType type = PropertyDetails(details).type();
-  return Smi::FromInt(static_cast<int>(type));
+  CONVERT_PROPERTY_DETAILS_CHECKED(details, 0);
+  return Smi::FromInt(static_cast<int>(details.type()));
 }
 
 
@@ -10634,9 +10633,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugPropertyTypeFromDetails) {
 // args[0]: smi with property details.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugPropertyAttributesFromDetails) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(Smi, details, args[0]);
-  PropertyAttributes attributes = PropertyDetails(details).attributes();
-  return Smi::FromInt(static_cast<int>(attributes));
+  CONVERT_PROPERTY_DETAILS_CHECKED(details, 0);
+  return Smi::FromInt(static_cast<int>(details.attributes()));
 }
 
 
@@ -10644,9 +10642,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugPropertyAttributesFromDetails) {
 // args[0]: smi with property details.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugPropertyIndexFromDetails) {
   ASSERT(args.length() == 1);
-  CONVERT_CHECKED(Smi, details, args[0]);
-  int index = PropertyDetails(details).index();
-  return Smi::FromInt(index);
+  CONVERT_PROPERTY_DETAILS_CHECKED(details, 0);
+  return Smi::FromInt(details.index());
 }
 
 
@@ -11607,7 +11604,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetScopeCount) {
       RUNTIME_ARGUMENTS(isolate, args));
     if (!maybe_check->ToObject(&check)) return maybe_check;
   }
-  CONVERT_CHECKED(Smi, wrapped_id, args[1]);
+  CONVERT_SMI_ARG_CHECKED(wrapped_id, 1);
 
   // Get the frame where the debugging is performed.
   StackFrame::Id id = UnwrapFrameId(wrapped_id);
@@ -11649,7 +11646,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetScopeDetails) {
       RUNTIME_ARGUMENTS(isolate, args));
     if (!maybe_check->ToObject(&check)) return maybe_check;
   }
-  CONVERT_CHECKED(Smi, wrapped_id, args[1]);
+  CONVERT_SMI_ARG_CHECKED(wrapped_id, 1);
   CONVERT_NUMBER_CHECKED(int, inlined_jsframe_index, Int32, args[2]);
   CONVERT_NUMBER_CHECKED(int, index, Int32, args[3]);
 
@@ -11789,7 +11786,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetThreadDetails) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_SetDisableBreak) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
-  CONVERT_BOOLEAN_CHECKED(disable_break, args[0]);
+  CONVERT_BOOLEAN_CHECKED(disable_break, 0);
   isolate->debug()->set_disable_break(disable_break);
   return  isolate->heap()->undefined_value();
 }
@@ -11973,7 +11970,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ChangeBreakOnException) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 2);
   RUNTIME_ASSERT(args[0]->IsNumber());
-  CONVERT_BOOLEAN_CHECKED(enable, args[1]);
+  CONVERT_BOOLEAN_CHECKED(enable, 1);
 
   // If the number doesn't match an enum value, the ChangeBreakOnException
   // function will default to affecting caught exceptions.
@@ -12188,10 +12185,10 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugEvaluate) {
       return maybe_check_result;
     }
   }
-  CONVERT_CHECKED(Smi, wrapped_id, args[1]);
+  CONVERT_SMI_ARG_CHECKED(wrapped_id, 1);
   CONVERT_NUMBER_CHECKED(int, inlined_jsframe_index, Int32, args[2]);
   CONVERT_ARG_CHECKED(String, source, 3);
-  CONVERT_BOOLEAN_CHECKED(disable_break, args[4]);
+  CONVERT_BOOLEAN_CHECKED(disable_break, 4);
   Handle<Object> additional_context(args[5]);
 
   // Handle the processing of break.
@@ -12328,7 +12325,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugEvaluateGlobal) {
     }
   }
   CONVERT_ARG_CHECKED(String, source, 1);
-  CONVERT_BOOLEAN_CHECKED(disable_break, args[2]);
+  CONVERT_BOOLEAN_CHECKED(disable_break, 2);
   Handle<Object> additional_context(args[3]);
 
   // Handle the processing of break.
@@ -12501,7 +12498,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugReferencedBy) {
   // Object* locals that are not protected by handles.
 
   // Check parameters.
-  CONVERT_CHECKED(JSObject, target, args[0]);
+  CONVERT_CHECKED(JSObject, target, 0);
   Object* instance_filter = args[1];
   RUNTIME_ASSERT(instance_filter->IsUndefined() ||
                  instance_filter->IsJSObject());
@@ -12589,7 +12586,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugConstructedBy) {
                                      "%DebugConstructedBy");
 
   // Check parameters.
-  CONVERT_CHECKED(JSFunction, constructor, args[0]);
+  CONVERT_CHECKED(JSFunction, constructor, 0);
   CONVERT_NUMBER_CHECKED(int32_t, max_references, Int32, args[1]);
   RUNTIME_ASSERT(max_references >= 0);
 
@@ -12633,7 +12630,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugConstructedBy) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugGetPrototype) {
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSObject, obj, args[0]);
+  CONVERT_CHECKED(JSObject, obj, 0);
 
   // Use the __proto__ accessor.
   return Accessors::ObjectPrototype.getter(obj, NULL);
@@ -12683,7 +12680,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_FunctionGetInferredName) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(JSFunction, f, args[0]);
+  CONVERT_CHECKED(JSFunction, f, 0);
   return f->shared()->inferred_name();
 }
 
@@ -12720,7 +12717,7 @@ RUNTIME_FUNCTION(MaybeObject*,
                  Runtime_LiveEditFindSharedFunctionInfosForScript) {
   ASSERT(args.length() == 1);
   HandleScope scope(isolate);
-  CONVERT_CHECKED(JSValue, script_value, args[0]);
+  CONVERT_CHECKED(JSValue, script_value, 0);
 
 
   Handle<Script> script = Handle<Script>(Script::cast(script_value->value()));
@@ -12766,7 +12763,7 @@ RUNTIME_FUNCTION(MaybeObject*,
 RUNTIME_FUNCTION(MaybeObject*, Runtime_LiveEditGatherCompileInfo) {
   ASSERT(args.length() == 2);
   HandleScope scope(isolate);
-  CONVERT_CHECKED(JSValue, script, args[0]);
+  CONVERT_CHECKED(JSValue, script, 0);
   CONVERT_ARG_CHECKED(String, source, 1);
   Handle<Script> script_handle = Handle<Script>(Script::cast(script->value()));
 
@@ -12785,13 +12782,12 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_LiveEditGatherCompileInfo) {
 RUNTIME_FUNCTION(MaybeObject*, Runtime_LiveEditReplaceScript) {
   ASSERT(args.length() == 3);
   HandleScope scope(isolate);
-  CONVERT_CHECKED(JSValue, original_script_value, args[0]);
+  CONVERT_CHECKED(JSValue, original_script_value, 0);
   CONVERT_ARG_CHECKED(String, new_source, 1);
   Handle<Object> old_script_name(args[2], isolate);
 
-  CONVERT_CHECKED(Script, original_script_pointer,
-                  original_script_value->value());
-  Handle<Script> original_script(original_script_pointer);
+  RUNTIME_ASSERT(original_script_value->value()->IsScript());
+  Handle<Script> original_script(Script::cast(original_script_value->value()));
 
   Object* old_script = LiveEdit::ChangeScriptSource(original_script,
                                                     new_source,
@@ -12834,7 +12830,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_LiveEditFunctionSetScript) {
   if (function_object->IsJSValue()) {
     Handle<JSValue> function_wrapper = Handle<JSValue>::cast(function_object);
     if (script_object->IsJSValue()) {
-      CONVERT_CHECKED(Script, script, JSValue::cast(*script_object)->value());
+      RUNTIME_ASSERT(JSValue::cast(*script_object)->value()->IsScript());
+      Script* script = Script::cast(JSValue::cast(*script_object)->value());
       script_object = Handle<Object>(script, isolate);
     }
 
@@ -12888,7 +12885,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_LiveEditCheckAndDropActivations) {
   ASSERT(args.length() == 2);
   HandleScope scope(isolate);
   CONVERT_ARG_CHECKED(JSArray, shared_array, 0);
-  CONVERT_BOOLEAN_CHECKED(do_drop, args[1]);
+  CONVERT_BOOLEAN_CHECKED(do_drop, 1);
 
   return *LiveEdit::CheckAndDropActivations(shared_array, do_drop);
 }
@@ -12949,7 +12946,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ExecuteInDebugContext) {
   ASSERT(args.length() == 2);
   HandleScope scope(isolate);
   CONVERT_ARG_CHECKED(JSFunction, function, 0);
-  CONVERT_BOOLEAN_CHECKED(without_debugger, args[1]);
+  CONVERT_BOOLEAN_CHECKED(without_debugger, 1);
 
   Handle<Object> result;
   bool pending_exception;
@@ -12973,7 +12970,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ExecuteInDebugContext) {
 
 // Sets a v8 flag.
 RUNTIME_FUNCTION(MaybeObject*, Runtime_SetFlags) {
-  CONVERT_CHECKED(String, arg, args[0]);
+  CONVERT_CHECKED(String, arg, 0);
   SmartArrayPointer<char> flags =
       arg->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL);
   FlagList::SetFlagsFromString(*flags, StrLength(*flags));
@@ -13257,7 +13254,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_GetScript) {
 
   ASSERT(args.length() == 1);
 
-  CONVERT_CHECKED(String, script_name, args[0]);
+  CONVERT_CHECKED(String, script_name, 0);
 
   // Find the requested script.
   Handle<Object> result =
@@ -13397,7 +13394,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_Abort) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetFromCache) {
   // This is only called from codegen, so checks might be more lax.
-  CONVERT_CHECKED(JSFunctionResultCache, cache, args[0]);
+  CONVERT_CHECKED(JSFunctionResultCache, cache, 0);
   Object* key = args[1];
 
   int finger_index = cache->finger_index();
@@ -13507,25 +13504,25 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_NewMessageObject) {
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_MessageGetType) {
-  CONVERT_CHECKED(JSMessageObject, message, args[0]);
+  CONVERT_CHECKED(JSMessageObject, message, 0);
   return message->type();
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_MessageGetArguments) {
-  CONVERT_CHECKED(JSMessageObject, message, args[0]);
+  CONVERT_CHECKED(JSMessageObject, message, 0);
   return message->arguments();
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_MessageGetStartPosition) {
-  CONVERT_CHECKED(JSMessageObject, message, args[0]);
+  CONVERT_CHECKED(JSMessageObject, message, 0);
   return Smi::FromInt(message->start_position());
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_MessageGetScript) {
-  CONVERT_CHECKED(JSMessageObject, message, args[0]);
+  CONVERT_CHECKED(JSMessageObject, message, 0);
   return message->script();
 }
 
@@ -13579,8 +13576,8 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ListNatives) {
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_Log) {
   ASSERT(args.length() == 2);
-  CONVERT_CHECKED(String, format, args[0]);
-  CONVERT_CHECKED(JSArray, elms, args[1]);
+  CONVERT_CHECKED(String, format, 0);
+  CONVERT_CHECKED(JSArray, elms, 1);
   String::FlatContent format_content = format->GetFlatContent();
   RUNTIME_ASSERT(format_content.IsAscii());
   Vector<const char> chars = format_content.ToAsciiVector();
@@ -13597,7 +13594,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_IS_VAR) {
 
 #define ELEMENTS_KIND_CHECK_RUNTIME_FUNCTION(Name)        \
   RUNTIME_FUNCTION(MaybeObject*, Runtime_Has##Name) {     \
-    CONVERT_CHECKED(JSObject, obj, args[0]);              \
+    CONVERT_CHECKED(JSObject, obj, 0);              \
     return isolate->heap()->ToBoolean(obj->Has##Name());  \
   }
 
@@ -13621,8 +13618,8 @@ ELEMENTS_KIND_CHECK_RUNTIME_FUNCTION(ExternalDoubleElements)
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_HaveSameMap) {
   ASSERT(args.length() == 2);
-  CONVERT_CHECKED(JSObject, obj1, args[0]);
-  CONVERT_CHECKED(JSObject, obj2, args[1]);
+  CONVERT_CHECKED(JSObject, obj1, 0);
+  CONVERT_CHECKED(JSObject, obj2, 1);
   return isolate->heap()->ToBoolean(obj1->map() == obj2->map());
 }