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refactor: extract validateSuperclass helper and move subclassing tests to inheritance directory

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This commit is contained in:
Bob Nystrom
2015-02-27 16:08:27 +00:00
parent d7d067b960
commit 3a8bc85674
18 changed files with 56 additions and 49 deletions
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src/wren_vm.c
+40 -21
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@@ -478,6 +478,41 @@ static bool importVariable(WrenVM* vm, Value moduleName, Value variableName,
return false;
}
// Verifies that [superclass] is a valid object to inherit from. That means it
// must be a class and cannot be the class of any built-in type.
//
// If successful, returns NULL. Otherwise, returns a string for the runtime
// error message.
static ObjString* validateSuperclass(WrenVM* vm, ObjString* name,
Value superclassValue)
{
// Make sure the superclass is a class.
if (!IS_CLASS(superclassValue))
{
return AS_STRING(wrenNewString(vm, "Must inherit from a class.", 26));
}
// Make sure it doesn't inherit from a sealed built-in type. Primitive methods
// on these classes assume the instance is one of the other Obj___ types and
// will fail horribly if it's actually an ObjInstance.
ObjClass* superclass = AS_CLASS(superclassValue);
if (superclass == vm->classClass ||
superclass == vm->fiberClass ||
superclass == vm->fnClass || // Includes OBJ_CLOSURE.
superclass == vm->listClass ||
superclass == vm->mapClass ||
superclass == vm->rangeClass ||
superclass == vm->stringClass)
{
char message[70 + MAX_VARIABLE_NAME];
sprintf(message, "%s cannot inherit from %s.",
name->value, superclass->name->value);
return AS_STRING(wrenNewString(vm, message, strlen(message)));
}
return NULL;
}
// The main bytecode interpreter loop. This is where the magic happens. It is
// also, as you can imagine, highly performance critical. Returns `true` if the
// fiber completed without error.
@@ -1083,30 +1118,14 @@ static bool runInterpreter(WrenVM* vm)
CASE_CODE(CLASS):
{
ObjString* name = AS_STRING(PEEK2());
ObjClass* superclass = vm->objectClass;
ObjClass* superclass;
if (IS_NULL(PEEK()))
// Use implicit Object superclass if none given.
if (!IS_NULL(PEEK()))
{
// Implicit Object superclass.
superclass = vm->objectClass;
}
else
{
// TODO: Handle the superclass not being a class object!
ObjString* error = validateSuperclass(vm, name, PEEK());
if (error != NULL) RUNTIME_ERROR(error);
superclass = AS_CLASS(PEEK());
if (superclass == vm->classClass ||
superclass == vm->fiberClass ||
superclass == vm->fnClass ||
superclass == vm->listClass || /* This covers also OBJ_CLOSURE */
superclass == vm->mapClass ||
superclass == vm->rangeClass ||
superclass == vm->stringClass )
{
char message[70 + MAX_VARIABLE_NAME];
sprintf(message,
"Class '%s' may not subclass a built-in", name->value);
RUNTIME_ERROR(AS_STRING(wrenNewString(vm, message, strlen(message))));
}
}
int numFields = READ_BYTE();