void wrenMarkObj(WrenVM* vm, Obj* obj)
{
#if WREN_DEBUG_TRACE_MEMORY
static int indent = 0;
indent++;
for (int i = 0; i < indent; i++) printf(" ");
printf("mark ");
wrenPrintValue(OBJ_VAL(obj));
printf(" @ %p\n", obj);
#endif
// Traverse the object's fields.
switch (obj->type)
{
case OBJ_CLASS: markClass( vm, (ObjClass*) obj); break;
case OBJ_CLOSURE: markClosure( vm, (ObjClosure*) obj); break;
case OBJ_FIBER: markFiber( vm, (ObjFiber*) obj); break;
case OBJ_FN: markFn( vm, (ObjFn*) obj); break;
case OBJ_INSTANCE: markInstance(vm, (ObjInstance*)obj); break;
case OBJ_LIST: markList( vm, (ObjList*) obj); break;
case OBJ_RANGE: setMarkedFlag(obj); break;
case OBJ_STRING: markString( vm, (ObjString*) obj); break;
case OBJ_UPVALUE: markUpvalue( vm, (Upvalue*) obj); break;
}
#if WREN_DEBUG_TRACE_MEMORY
indent--;
#endif
}
ObjClass* wrenNewClass(WrenVM* vm, ObjClass* superclass, int numFields,
ObjString* name)
{
// Create the metaclass.
Value metaclassName = wrenStringFormat(vm, "@ metaclass", OBJ_VAL(name));
wrenPushRoot(vm, AS_OBJ(metaclassName));
ObjClass* metaclass = wrenNewSingleClass(vm, 0, AS_STRING(metaclassName));
metaclass->obj.classObj = vm->classClass;
wrenPopRoot(vm);
// Make sure the metaclass isn't collected when we allocate the class.
wrenPushRoot(vm, (Obj*)metaclass);
// Metaclasses always inherit Class and do not parallel the non-metaclass
// hierarchy.
wrenBindSuperclass(vm, metaclass, vm->classClass);
ObjClass* classObj = wrenNewSingleClass(vm, numFields, name);
// Make sure the class isn't collected while the inherited methods are being
// bound.
wrenPushRoot(vm, (Obj*)classObj);
classObj->obj.classObj = metaclass;
wrenBindSuperclass(vm, classObj, superclass);
wrenPopRoot(vm);
wrenPopRoot(vm);
return classObj;
}
// Validates that the given argument in [args] is a function. Returns true if
// it is. If not, reports an error and returns false.
static bool validateFn(WrenVM* vm, Value* args, int index, const char* argName)
{
if (IS_FN(args[index]) || IS_CLOSURE(args[index])) return true;
args[0] = OBJ_VAL(wrenStringConcat(vm, argName, " must be a function."));
return false;
}
// Validates that the given argument in [args] is a Num. Returns true if it is.
// If not, reports an error and returns false.
static bool validateNum(WrenVM* vm, Value* args, int index, const char* argName)
{
if (IS_NUM(args[index])) return true;
args[0] = OBJ_VAL(wrenStringConcat(vm, argName, " must be a number."));
return false;
}
static void defineMethod(WrenVM* vm, const char* className,
const char* methodName, int numParams,
WrenForeignMethodFn methodFn, bool isStatic)
{
ASSERT(className != NULL, "Must provide class name.");
int length = (int)strlen(methodName);
ASSERT(methodName != NULL, "Must provide method name.");
ASSERT(strlen(methodName) < MAX_METHOD_NAME, "Method name too long.");
ASSERT(numParams >= 0, "numParams cannot be negative.");
ASSERT(numParams <= MAX_PARAMETERS, "Too many parameters.");
ASSERT(methodFn != NULL, "Must provide method function.");
// Find or create the class to bind the method to.
int classSymbol = wrenSymbolTableFind(&vm->globalNames,
className, strlen(className));
ObjClass* classObj;
if (classSymbol != -1)
{
// TODO: Handle name is not class.
classObj = AS_CLASS(vm->globals.data[classSymbol]);
}
else
{
// The class doesn't already exist, so create it.
size_t length = strlen(className);
ObjString* nameString = AS_STRING(wrenNewString(vm, className, length));
WREN_PIN(vm, nameString);
// TODO: Allow passing in name for superclass?
classObj = wrenNewClass(vm, vm->objectClass, 0, nameString);
wrenDefineGlobal(vm, className, length, OBJ_VAL(classObj));
WREN_UNPIN(vm);
}
// Create a name for the method, including its arity.
char name[MAX_METHOD_SIGNATURE];
strncpy(name, methodName, length);
for (int i = 0; i < numParams; i++)
{
name[length++] = ' ';
}
name[length] = '\0';
// Bind the method.
int methodSymbol = wrenSymbolTableEnsure(vm, &vm->methodNames, name, length);
Method method;
method.type = METHOD_FOREIGN;
method.fn.foreign = methodFn;
if (isStatic) classObj = classObj->obj.classObj;
wrenBindMethod(vm, classObj, methodSymbol, method);
}
// Validates that [value] is an integer. Returns true if it is. If not, reports
// an error and returns false.
static bool validateIntValue(WrenVM* vm, Value* args, double value,
const char* argName)
{
if (trunc(value) == value) return true;
args[0] = OBJ_VAL(wrenStringConcat(vm, argName, " must be an integer."));
return false;
}
void metaCompile(WrenVM* vm)
{
// Evaluate the code in the module where the calling function was defined.
// That's one stack frame back from the top since the top-most frame is the
// helper eval() method in Meta itself.
Value callingFn = OBJ_VAL(vm->fiber->frames[vm->fiber->numFrames - 2].fn);
ObjModule* module = IS_FN(callingFn)
? AS_FN(callingFn)->module
: AS_CLOSURE(callingFn)->fn->module;
// Compile it.
ObjFn* fn = wrenCompile(vm, module, wrenGetArgumentString(vm, 1), false);
if (fn == NULL) return;
// Return the result. We can't use the public API for this since we have a
// bare ObjFn.
*vm->foreignCallSlot = OBJ_VAL(fn);
vm->foreignCallSlot = NULL;
}
Value wrenNewRange(WrenVM* vm, double from, double to, bool isInclusive)
{
ObjRange* range = allocate(vm, sizeof(ObjRange) + 16);
initObj(vm, &range->obj, OBJ_RANGE, vm->rangeClass);
range->from = from;
range->to = to;
range->isInclusive = isInclusive;
return OBJ_VAL(range);
}
Value wrenNewUninitializedString(WrenVM* vm, size_t length)
{
// Allocate before the string object in case this triggers a GC which would
// free the string object.
char* heapText = allocate(vm, length + 1);
ObjString* string = allocate(vm, sizeof(ObjString));
initObj(vm, &string->obj, OBJ_STRING, vm->stringClass);
string->value = heapText;
return OBJ_VAL(string);
}
static ObjClass* defineClass(WrenVM* vm, const char* name)
{
size_t length = strlen(name);
ObjString* nameString = AS_STRING(wrenNewString(vm, name, length));
WREN_PIN(vm, nameString);
ObjClass* classObj = wrenNewClass(vm, vm->objectClass, 0, nameString);
wrenDefineGlobal(vm, name, length, OBJ_VAL(classObj));
WREN_UNPIN(vm);
return classObj;
}
// Creates either the Object or Class class in the core module with [name].
static ObjClass* defineClass(WrenVM* vm, ObjModule* module, const char* name)
{
ObjString* nameString = AS_STRING(wrenStringFormat(vm, "$", name));
wrenPushRoot(vm, (Obj*)nameString);
ObjClass* classObj = wrenNewSingleClass(vm, 0, nameString);
wrenDefineVariable(vm, module, name, nameString->length, OBJ_VAL(classObj));
wrenPopRoot(vm);
return classObj;
}
Value wrenNewInstance(WrenVM* vm, ObjClass* classObj)
{
ObjInstance* instance = allocate(vm,
sizeof(ObjInstance) + classObj->numFields * sizeof(Value));
initObj(vm, &instance->obj, OBJ_INSTANCE, classObj);
// Initialize fields to null.
for (int i = 0; i < classObj->numFields; i++)
{
instance->fields[i] = NULL_VAL;
}
return OBJ_VAL(instance);
}
void wrenFreeObj(WrenVM* vm, Obj* obj)
{
#if WREN_DEBUG_TRACE_MEMORY
printf("free ");
wrenPrintValue(OBJ_VAL(obj));
printf(" @ %p\n", obj);
#endif
switch (obj->type)
{
case OBJ_CLASS:
wrenMethodBufferClear(vm, &((ObjClass*)obj)->methods);
break;
case OBJ_FIBER:
{
ObjFiber* fiber = ((ObjFiber*)obj);
if (fiber->error != NULL) wrenReallocate(vm, fiber->error, 0, 0);
break;
}
case OBJ_FN:
{
ObjFn* fn = (ObjFn*)obj;
wrenReallocate(vm, fn->constants, 0, 0);
wrenReallocate(vm, fn->bytecode, 0, 0);
wrenReallocate(vm, fn->debug->name, 0, 0);
wrenReallocate(vm, fn->debug->sourceLines, 0, 0);
wrenReallocate(vm, fn->debug, 0, 0);
break;
}
case OBJ_LIST:
wrenReallocate(vm, ((ObjList*)obj)->elements, 0, 0);
break;
case OBJ_STRING:
wrenReallocate(vm, ((ObjString*)obj)->value, 0, 0);
break;
case OBJ_CLOSURE:
case OBJ_INSTANCE:
case OBJ_RANGE:
case OBJ_UPVALUE:
break;
}
wrenReallocate(vm, obj, 0, 0);
}
// Validates that [value] is an integer within `[0, count)`. Also allows
// negative indices which map backwards from the end. Returns the valid positive
// index value. If invalid, reports an error and returns -1.
static int validateIndexValue(WrenVM* vm, Value* args, int count, double value,
const char* argName)
{
if (!validateIntValue(vm, args, value, argName)) return -1;
int index = (int)value;
// Negative indices count from the end.
if (index < 0) index = count + index;
// Check bounds.
if (index >= 0 && index < count) return index;
args[0] = OBJ_VAL(wrenStringConcat(vm, argName, " out of bounds."));
return -1;
}
Value wrenNewString(WrenVM* vm, const char* text, size_t length)
{
// Allow NULL if the string is empty since byte buffers don't allocate any
// characters for a zero-length string.
ASSERT(length == 0 || text != NULL, "Unexpected NULL string.");
// TODO: Don't allocate a heap string at all for zero-length strings.
ObjString* string = AS_STRING(wrenNewUninitializedString(vm, length));
// Copy the string (if given one).
if (length > 0) strncpy(string->value, text, length);
string->value[length] = '\0';
return OBJ_VAL(string);
}
Value wrenNewString(WrenVM* vm, const char* text, size_t length)
{
// Allocate before the string object in case this triggers a GC which would
// free the string object.
char* heapText = allocate(vm, length + 1);
ObjString* string = allocate(vm, sizeof(ObjString));
initObj(vm, &string->obj, OBJ_STRING);
string->value = heapText;
// Copy the string (if given one).
if (text != NULL)
{
strncpy(heapText, text, length);
heapText[length] = '\0';
}
return OBJ_VAL(string);
}
// Puts [fiber] into a runtime failed state because of [error].
//
// Returns the fiber that should receive the error or `NULL` if no fiber
// caught it.
static ObjFiber* runtimeError(WrenVM* vm, ObjFiber* fiber, ObjString* error)
{
ASSERT(fiber->error == NULL, "Can only fail once.");
// Store the error in the fiber so it can be accessed later.
fiber->error = error;
// If the caller ran this fiber using "try", give it the error.
if (fiber->callerIsTrying)
{
ObjFiber* caller = fiber->caller;
// Make the caller's try method return the error message.
*(caller->stackTop - 1) = OBJ_VAL(fiber->error);
return caller;
}
// If we got here, nothing caught the error, so show the stack trace.
wrenDebugPrintStackTrace(vm, fiber);
return NULL;
}
void wrenInitializeCore(WrenVM* vm)
{
ObjModule* coreModule = wrenNewModule(vm, NULL);
wrenPushRoot(vm, (Obj*)coreModule);
// The core module's key is null in the module map.
wrenMapSet(vm, vm->modules, NULL_VAL, OBJ_VAL(coreModule));
wrenPopRoot(vm); // coreModule.
// Define the root Object class. This has to be done a little specially
// because it has no superclass.
vm->objectClass = defineClass(vm, coreModule, "Object");
PRIMITIVE(vm->objectClass, "!", object_not);
PRIMITIVE(vm->objectClass, "==(_)", object_eqeq);
PRIMITIVE(vm->objectClass, "!=(_)", object_bangeq);
PRIMITIVE(vm->objectClass, "is(_)", object_is);
PRIMITIVE(vm->objectClass, "toString", object_toString);
PRIMITIVE(vm->objectClass, "type", object_type);
// Now we can define Class, which is a subclass of Object.
vm->classClass = defineClass(vm, coreModule, "Class");
wrenBindSuperclass(vm, vm->classClass, vm->objectClass);
PRIMITIVE(vm->classClass, "name", class_name);
PRIMITIVE(vm->classClass, "supertype", class_supertype);
PRIMITIVE(vm->classClass, "toString", class_toString);
// Finally, we can define Object's metaclass which is a subclass of Class.
ObjClass* objectMetaclass = defineClass(vm, coreModule, "Object metaclass");
// Wire up the metaclass relationships now that all three classes are built.
vm->objectClass->obj.classObj = objectMetaclass;
objectMetaclass->obj.classObj = vm->classClass;
vm->classClass->obj.classObj = vm->classClass;
// Do this after wiring up the metaclasses so objectMetaclass doesn't get
// collected.
wrenBindSuperclass(vm, objectMetaclass, vm->classClass);
PRIMITIVE(objectMetaclass, "same(_,_)", object_same);
// The core class diagram ends up looking like this, where single lines point
// to a class's superclass, and double lines point to its metaclass:
//
// .------------------------------------. .====.
// | .---------------. | # #
// v | v | v #
// .---------. .-------------------. .-------. #
// | Object |==>| Object metaclass |==>| Class |=="
// '---------' '-------------------' '-------'
// ^ ^ ^ ^ ^
// | .--------------' # | #
// | | # | #
// .---------. .-------------------. # | # -.
// | Base |==>| Base metaclass |======" | # |
// '---------' '-------------------' | # |
// ^ | # |
// | .------------------' # | Example classes
// | | # |
// .---------. .-------------------. # |
// | Derived |==>| Derived metaclass |==========" |
// '---------' '-------------------' -'
// The rest of the classes can now be defined normally.
wrenInterpretInModule(vm, NULL, coreModuleSource);
vm->boolClass = AS_CLASS(wrenFindVariable(vm, coreModule, "Bool"));
PRIMITIVE(vm->boolClass, "toString", bool_toString);
PRIMITIVE(vm->boolClass, "!", bool_not);
vm->fiberClass = AS_CLASS(wrenFindVariable(vm, coreModule, "Fiber"));
PRIMITIVE(vm->fiberClass->obj.classObj, "new(_)", fiber_new);
PRIMITIVE(vm->fiberClass->obj.classObj, "abort(_)", fiber_abort);
PRIMITIVE(vm->fiberClass->obj.classObj, "current", fiber_current);
PRIMITIVE(vm->fiberClass->obj.classObj, "suspend()", fiber_suspend);
PRIMITIVE(vm->fiberClass->obj.classObj, "yield()", fiber_yield);
PRIMITIVE(vm->fiberClass->obj.classObj, "yield(_)", fiber_yield1);
PRIMITIVE(vm->fiberClass, "call()", fiber_call);
PRIMITIVE(vm->fiberClass, "call(_)", fiber_call1);
PRIMITIVE(vm->fiberClass, "error", fiber_error);
PRIMITIVE(vm->fiberClass, "isDone", fiber_isDone);
PRIMITIVE(vm->fiberClass, "transfer()", fiber_transfer);
PRIMITIVE(vm->fiberClass, "transfer(_)", fiber_transfer1);
PRIMITIVE(vm->fiberClass, "transferError(_)", fiber_transferError);
PRIMITIVE(vm->fiberClass, "try()", fiber_try);
vm->fnClass = AS_CLASS(wrenFindVariable(vm, coreModule, "Fn"));
PRIMITIVE(vm->fnClass->obj.classObj, "new(_)", fn_new);
PRIMITIVE(vm->fnClass, "arity", fn_arity);
fnCall(vm, "call()");
fnCall(vm, "call(_)");
fnCall(vm, "call(_,_)");
fnCall(vm, "call(_,_,_)");
fnCall(vm, "call(_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_,_,_,_,_)");
fnCall(vm, "call(_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_)");
PRIMITIVE(vm->fnClass, "toString", fn_toString);
vm->nullClass = AS_CLASS(wrenFindVariable(vm, coreModule, "Null"));
PRIMITIVE(vm->nullClass, "!", null_not);
PRIMITIVE(vm->nullClass, "toString", null_toString);
vm->numClass = AS_CLASS(wrenFindVariable(vm, coreModule, "Num"));
PRIMITIVE(vm->numClass->obj.classObj, "fromString(_)", num_fromString);
PRIMITIVE(vm->numClass->obj.classObj, "pi", num_pi);
PRIMITIVE(vm->numClass, "-(_)", num_minus);
PRIMITIVE(vm->numClass, "+(_)", num_plus);
PRIMITIVE(vm->numClass, "*(_)", num_multiply);
PRIMITIVE(vm->numClass, "/(_)", num_divide);
PRIMITIVE(vm->numClass, "<(_)", num_lt);
PRIMITIVE(vm->numClass, ">(_)", num_gt);
PRIMITIVE(vm->numClass, "<=(_)", num_lte);
PRIMITIVE(vm->numClass, ">=(_)", num_gte);
PRIMITIVE(vm->numClass, "&(_)", num_bitwiseAnd);
PRIMITIVE(vm->numClass, "|(_)", num_bitwiseOr);
PRIMITIVE(vm->numClass, "^(_)", num_bitwiseXor);
PRIMITIVE(vm->numClass, "<<(_)", num_bitwiseLeftShift);
PRIMITIVE(vm->numClass, ">>(_)", num_bitwiseRightShift);
PRIMITIVE(vm->numClass, "abs", num_abs);
PRIMITIVE(vm->numClass, "acos", num_acos);
PRIMITIVE(vm->numClass, "asin", num_asin);
PRIMITIVE(vm->numClass, "atan", num_atan);
PRIMITIVE(vm->numClass, "ceil", num_ceil);
PRIMITIVE(vm->numClass, "cos", num_cos);
PRIMITIVE(vm->numClass, "floor", num_floor);
PRIMITIVE(vm->numClass, "-", num_negate);
PRIMITIVE(vm->numClass, "sin", num_sin);
PRIMITIVE(vm->numClass, "sqrt", num_sqrt);
PRIMITIVE(vm->numClass, "tan", num_tan);
PRIMITIVE(vm->numClass, "%(_)", num_mod);
PRIMITIVE(vm->numClass, "~", num_bitwiseNot);
PRIMITIVE(vm->numClass, "..(_)", num_dotDot);
PRIMITIVE(vm->numClass, "...(_)", num_dotDotDot);
PRIMITIVE(vm->numClass, "atan(_)", num_atan2);
PRIMITIVE(vm->numClass, "fraction", num_fraction);
PRIMITIVE(vm->numClass, "isInfinity", num_isInfinity);
PRIMITIVE(vm->numClass, "isInteger", num_isInteger);
PRIMITIVE(vm->numClass, "isNan", num_isNan);
PRIMITIVE(vm->numClass, "sign", num_sign);
PRIMITIVE(vm->numClass, "toString", num_toString);
PRIMITIVE(vm->numClass, "truncate", num_truncate);
// These are defined just so that 0 and -0 are equal, which is specified by
// IEEE 754 even though they have different bit representations.
PRIMITIVE(vm->numClass, "==(_)", num_eqeq);
PRIMITIVE(vm->numClass, "!=(_)", num_bangeq);
vm->stringClass = AS_CLASS(wrenFindVariable(vm, coreModule, "String"));
PRIMITIVE(vm->stringClass->obj.classObj, "fromCodePoint(_)", string_fromCodePoint);
PRIMITIVE(vm->stringClass, "+(_)", string_plus);
PRIMITIVE(vm->stringClass, "[_]", string_subscript);
PRIMITIVE(vm->stringClass, "byteAt_(_)", string_byteAt);
PRIMITIVE(vm->stringClass, "byteCount_", string_byteCount);
PRIMITIVE(vm->stringClass, "codePointAt_(_)", string_codePointAt);
PRIMITIVE(vm->stringClass, "contains(_)", string_contains);
PRIMITIVE(vm->stringClass, "endsWith(_)", string_endsWith);
PRIMITIVE(vm->stringClass, "indexOf(_)", string_indexOf);
PRIMITIVE(vm->stringClass, "iterate(_)", string_iterate);
PRIMITIVE(vm->stringClass, "iterateByte_(_)", string_iterateByte);
PRIMITIVE(vm->stringClass, "iteratorValue(_)", string_iteratorValue);
PRIMITIVE(vm->stringClass, "startsWith(_)", string_startsWith);
PRIMITIVE(vm->stringClass, "toString", string_toString);
vm->listClass = AS_CLASS(wrenFindVariable(vm, coreModule, "List"));
PRIMITIVE(vm->listClass->obj.classObj, "new()", list_new);
PRIMITIVE(vm->listClass, "[_]", list_subscript);
PRIMITIVE(vm->listClass, "[_]=(_)", list_subscriptSetter);
PRIMITIVE(vm->listClass, "add(_)", list_add);
PRIMITIVE(vm->listClass, "addCore_(_)", list_addCore);
PRIMITIVE(vm->listClass, "clear()", list_clear);
PRIMITIVE(vm->listClass, "count", list_count);
PRIMITIVE(vm->listClass, "insert(_,_)", list_insert);
PRIMITIVE(vm->listClass, "iterate(_)", list_iterate);
PRIMITIVE(vm->listClass, "iteratorValue(_)", list_iteratorValue);
PRIMITIVE(vm->listClass, "removeAt(_)", list_removeAt);
vm->mapClass = AS_CLASS(wrenFindVariable(vm, coreModule, "Map"));
PRIMITIVE(vm->mapClass->obj.classObj, "new()", map_new);
PRIMITIVE(vm->mapClass, "[_]", map_subscript);
PRIMITIVE(vm->mapClass, "[_]=(_)", map_subscriptSetter);
PRIMITIVE(vm->mapClass, "addCore_(_,_)", map_addCore);
PRIMITIVE(vm->mapClass, "clear()", map_clear);
PRIMITIVE(vm->mapClass, "containsKey(_)", map_containsKey);
PRIMITIVE(vm->mapClass, "count", map_count);
PRIMITIVE(vm->mapClass, "remove(_)", map_remove);
PRIMITIVE(vm->mapClass, "iterate_(_)", map_iterate);
PRIMITIVE(vm->mapClass, "keyIteratorValue_(_)", map_keyIteratorValue);
PRIMITIVE(vm->mapClass, "valueIteratorValue_(_)", map_valueIteratorValue);
vm->rangeClass = AS_CLASS(wrenFindVariable(vm, coreModule, "Range"));
PRIMITIVE(vm->rangeClass, "from", range_from);
PRIMITIVE(vm->rangeClass, "to", range_to);
PRIMITIVE(vm->rangeClass, "min", range_min);
PRIMITIVE(vm->rangeClass, "max", range_max);
PRIMITIVE(vm->rangeClass, "isInclusive", range_isInclusive);
PRIMITIVE(vm->rangeClass, "iterate(_)", range_iterate);
PRIMITIVE(vm->rangeClass, "iteratorValue(_)", range_iteratorValue);
PRIMITIVE(vm->rangeClass, "toString", range_toString);
ObjClass* systemClass = AS_CLASS(wrenFindVariable(vm, coreModule, "System"));
PRIMITIVE(systemClass->obj.classObj, "clock", system_clock);
PRIMITIVE(systemClass->obj.classObj, "gc()", system_gc);
// TODO: Do we want to give these magic names that can't be called from
// regular code?
PRIMITIVE(systemClass->obj.classObj, "getModuleVariable(_,_)", system_getModuleVariable);
PRIMITIVE(systemClass->obj.classObj, "importModule(_)", system_importModule);
PRIMITIVE(systemClass->obj.classObj, "writeString_(_)", system_writeString);
// While bootstrapping the core types and running the core module, a number
// of string objects have been created, many of which were instantiated
// before stringClass was stored in the VM. Some of them *must* be created
// first -- the ObjClass for string itself has a reference to the ObjString
// for its name.
//
// These all currently have a NULL classObj pointer, so go back and assign
// them now that the string class is known.
for (Obj* obj = vm->first; obj != NULL; obj = obj->next)
{
if (obj->type == OBJ_STRING) obj->classObj = vm->stringClass;
}
}
// 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.
static bool runInterpreter(WrenVM* vm)
{
// Hoist these into local variables. They are accessed frequently in the loop
// but assigned less frequently. Keeping them in locals and updating them when
// a call frame has been pushed or popped gives a large speed boost.
register ObjFiber* fiber = vm->fiber;
register CallFrame* frame;
register Value* stackStart;
register uint8_t* ip;
register ObjFn* fn;
// These macros are designed to only be invoked within this function.
#define PUSH(value) (*fiber->stackTop++ = value)
#define POP() (*(--fiber->stackTop))
#define DROP() (fiber->stackTop--)
#define PEEK() (*(fiber->stackTop - 1))
#define PEEK2() (*(fiber->stackTop - 2))
#define READ_BYTE() (*ip++)
#define READ_SHORT() (ip += 2, (ip[-2] << 8) | ip[-1])
// Use this before a CallFrame is pushed to store the local variables back
// into the current one.
#define STORE_FRAME() frame->ip = ip
// Use this after a CallFrame has been pushed or popped to refresh the local
// variables.
#define LOAD_FRAME() \
frame = &fiber->frames[fiber->numFrames - 1]; \
stackStart = frame->stackStart; \
ip = frame->ip; \
if (frame->fn->type == OBJ_FN) \
{ \
fn = (ObjFn*)frame->fn; \
} \
else \
{ \
fn = ((ObjClosure*)frame->fn)->fn; \
}
// Terminates the current fiber with error string [error]. If another calling
// fiber is willing to catch the error, transfers control to it, otherwise
// exits the interpreter.
#define RUNTIME_ERROR(error) \
do { \
STORE_FRAME(); \
fiber = runtimeError(vm, fiber, error); \
if (fiber == NULL) return false; \
LOAD_FRAME(); \
DISPATCH(); \
} \
while (false)
#if WREN_COMPUTED_GOTO
// Note that the order of instructions here must exacly match the Code enum
// in wren_vm.h or horrendously bad things happen.
static void* dispatchTable[] = {
&&code_CONSTANT,
&&code_NULL,
&&code_FALSE,
&&code_TRUE,
&&code_LOAD_LOCAL_0,
&&code_LOAD_LOCAL_1,
&&code_LOAD_LOCAL_2,
&&code_LOAD_LOCAL_3,
&&code_LOAD_LOCAL_4,
&&code_LOAD_LOCAL_5,
&&code_LOAD_LOCAL_6,
&&code_LOAD_LOCAL_7,
&&code_LOAD_LOCAL_8,
&&code_LOAD_LOCAL,
&&code_STORE_LOCAL,
&&code_LOAD_UPVALUE,
&&code_STORE_UPVALUE,
&&code_LOAD_GLOBAL,
&&code_STORE_GLOBAL,
&&code_LOAD_FIELD_THIS,
&&code_STORE_FIELD_THIS,
&&code_LOAD_FIELD,
&&code_STORE_FIELD,
&&code_POP,
&&code_CALL_0,
&&code_CALL_1,
&&code_CALL_2,
&&code_CALL_3,
&&code_CALL_4,
&&code_CALL_5,
&&code_CALL_6,
&&code_CALL_7,
&&code_CALL_8,
&&code_CALL_9,
&&code_CALL_10,
&&code_CALL_11,
&&code_CALL_12,
&&code_CALL_13,
&&code_CALL_14,
&&code_CALL_15,
&&code_CALL_16,
&&code_SUPER_0,
&&code_SUPER_1,
&&code_SUPER_2,
&&code_SUPER_3,
&&code_SUPER_4,
&&code_SUPER_5,
&&code_SUPER_6,
&&code_SUPER_7,
&&code_SUPER_8,
&&code_SUPER_9,
&&code_SUPER_10,
&&code_SUPER_11,
&&code_SUPER_12,
&&code_SUPER_13,
&&code_SUPER_14,
&&code_SUPER_15,
&&code_SUPER_16,
&&code_JUMP,
&&code_LOOP,
&&code_JUMP_IF,
&&code_AND,
&&code_OR,
&&code_IS,
&&code_CLOSE_UPVALUE,
&&code_RETURN,
&&code_LIST,
&&code_CLOSURE,
&&code_CLASS,
&&code_METHOD_INSTANCE,
&&code_METHOD_STATIC,
&&code_END
};
#define INTERPRET_LOOP DISPATCH();
#define CASE_CODE(name) code_##name
#if WREN_DEBUG_TRACE_INSTRUCTIONS
// Prints the stack and instruction before each instruction is executed.
#define DISPATCH() \
{ \
wrenDebugPrintStack(fiber); \
wrenDebugPrintInstruction(vm, fn, (int)(ip - fn->bytecode)); \
instruction = *ip++; \
goto *dispatchTable[instruction]; \
}
#else
#define DISPATCH() goto *dispatchTable[instruction = READ_BYTE()];
#endif
#else
#define INTERPRET_LOOP for (;;) switch (instruction = READ_BYTE())
#define CASE_CODE(name) case CODE_##name
#define DISPATCH() break
#endif
LOAD_FRAME();
Code instruction;
INTERPRET_LOOP
{
CASE_CODE(LOAD_LOCAL_0):
CASE_CODE(LOAD_LOCAL_1):
CASE_CODE(LOAD_LOCAL_2):
CASE_CODE(LOAD_LOCAL_3):
CASE_CODE(LOAD_LOCAL_4):
CASE_CODE(LOAD_LOCAL_5):
CASE_CODE(LOAD_LOCAL_6):
CASE_CODE(LOAD_LOCAL_7):
CASE_CODE(LOAD_LOCAL_8):
PUSH(stackStart[instruction - CODE_LOAD_LOCAL_0]);
DISPATCH();
CASE_CODE(LOAD_LOCAL):
PUSH(stackStart[READ_BYTE()]);
DISPATCH();
CASE_CODE(LOAD_FIELD_THIS):
{
int field = READ_BYTE();
Value receiver = stackStart[0];
ASSERT(IS_INSTANCE(receiver), "Receiver should be instance.");
ObjInstance* instance = AS_INSTANCE(receiver);
ASSERT(field < instance->obj.classObj->numFields, "Out of bounds field.");
PUSH(instance->fields[field]);
DISPATCH();
}
CASE_CODE(POP): DROP(); DISPATCH();
CASE_CODE(NULL): PUSH(NULL_VAL); DISPATCH();
CASE_CODE(FALSE): PUSH(FALSE_VAL); DISPATCH();
CASE_CODE(TRUE): PUSH(TRUE_VAL); DISPATCH();
CASE_CODE(CALL_0):
CASE_CODE(CALL_1):
CASE_CODE(CALL_2):
CASE_CODE(CALL_3):
CASE_CODE(CALL_4):
CASE_CODE(CALL_5):
CASE_CODE(CALL_6):
CASE_CODE(CALL_7):
CASE_CODE(CALL_8):
CASE_CODE(CALL_9):
CASE_CODE(CALL_10):
CASE_CODE(CALL_11):
CASE_CODE(CALL_12):
CASE_CODE(CALL_13):
CASE_CODE(CALL_14):
CASE_CODE(CALL_15):
CASE_CODE(CALL_16):
{
// Add one for the implicit receiver argument.
int numArgs = instruction - CODE_CALL_0 + 1;
int symbol = READ_SHORT();
Value receiver = *(fiber->stackTop - numArgs);
ObjClass* classObj = wrenGetClassInline(vm, receiver);
// If the class's method table doesn't include the symbol, bail.
if (symbol >= classObj->methods.count)
{
RUNTIME_ERROR(methodNotFound(vm, classObj, symbol));
}
Method* method = &classObj->methods.data[symbol];
switch (method->type)
{
case METHOD_PRIMITIVE:
{
Value* args = fiber->stackTop - numArgs;
// After calling this, the result will be in the first arg slot.
switch (method->fn.primitive(vm, fiber, args))
{
case PRIM_VALUE:
// The result is now in the first arg slot. Discard the other
// stack slots.
fiber->stackTop -= numArgs - 1;
break;
case PRIM_ERROR:
RUNTIME_ERROR(AS_STRING(args[0]));
case PRIM_CALL:
STORE_FRAME();
callFunction(fiber, AS_OBJ(args[0]), numArgs);
LOAD_FRAME();
break;
case PRIM_RUN_FIBER:
STORE_FRAME();
fiber = AS_FIBER(args[0]);
LOAD_FRAME();
break;
}
break;
}
case METHOD_FOREIGN:
callForeign(vm, fiber, method->fn.foreign, numArgs);
break;
case METHOD_BLOCK:
STORE_FRAME();
callFunction(fiber, method->fn.obj, numArgs);
LOAD_FRAME();
break;
case METHOD_NONE:
RUNTIME_ERROR(methodNotFound(vm, classObj, symbol));
break;
}
DISPATCH();
}
CASE_CODE(STORE_LOCAL):
stackStart[READ_BYTE()] = PEEK();
DISPATCH();
CASE_CODE(CONSTANT):
PUSH(fn->constants[READ_SHORT()]);
DISPATCH();
CASE_CODE(SUPER_0):
CASE_CODE(SUPER_1):
CASE_CODE(SUPER_2):
CASE_CODE(SUPER_3):
CASE_CODE(SUPER_4):
CASE_CODE(SUPER_5):
CASE_CODE(SUPER_6):
CASE_CODE(SUPER_7):
CASE_CODE(SUPER_8):
CASE_CODE(SUPER_9):
CASE_CODE(SUPER_10):
CASE_CODE(SUPER_11):
CASE_CODE(SUPER_12):
CASE_CODE(SUPER_13):
CASE_CODE(SUPER_14):
CASE_CODE(SUPER_15):
CASE_CODE(SUPER_16):
{
// TODO: Almost completely copied from CALL. Unify somehow.
// Add one for the implicit receiver argument.
int numArgs = instruction - CODE_SUPER_0 + 1;
int symbol = READ_SHORT();
Value receiver = *(fiber->stackTop - numArgs);
ObjClass* classObj = wrenGetClassInline(vm, receiver);
// Ignore methods defined on the receiver's immediate class.
classObj = classObj->superclass;
// If the class's method table doesn't include the symbol, bail.
if (symbol >= classObj->methods.count)
{
RUNTIME_ERROR(methodNotFound(vm, classObj, symbol));
}
Method* method = &classObj->methods.data[symbol];
switch (method->type)
{
case METHOD_PRIMITIVE:
{
Value* args = fiber->stackTop - numArgs;
// After calling this, the result will be in the first arg slot.
switch (method->fn.primitive(vm, fiber, args))
{
case PRIM_VALUE:
// The result is now in the first arg slot. Discard the other
// stack slots.
fiber->stackTop -= numArgs - 1;
break;
case PRIM_ERROR:
RUNTIME_ERROR(AS_STRING(args[0]));
case PRIM_CALL:
STORE_FRAME();
callFunction(fiber, AS_OBJ(args[0]), numArgs);
LOAD_FRAME();
break;
case PRIM_RUN_FIBER:
STORE_FRAME();
fiber = AS_FIBER(args[0]);
LOAD_FRAME();
break;
}
break;
}
case METHOD_FOREIGN:
callForeign(vm, fiber, method->fn.foreign, numArgs);
break;
case METHOD_BLOCK:
STORE_FRAME();
callFunction(fiber, method->fn.obj, numArgs);
LOAD_FRAME();
break;
case METHOD_NONE:
RUNTIME_ERROR(methodNotFound(vm, classObj, symbol));
break;
}
DISPATCH();
}
CASE_CODE(LOAD_UPVALUE):
{
Upvalue** upvalues = ((ObjClosure*)frame->fn)->upvalues;
PUSH(*upvalues[READ_BYTE()]->value);
DISPATCH();
}
CASE_CODE(STORE_UPVALUE):
{
Upvalue** upvalues = ((ObjClosure*)frame->fn)->upvalues;
*upvalues[READ_BYTE()]->value = PEEK();
DISPATCH();
}
CASE_CODE(LOAD_GLOBAL):
PUSH(vm->globals.data[READ_SHORT()]);
DISPATCH();
CASE_CODE(STORE_GLOBAL):
vm->globals.data[READ_SHORT()] = PEEK();
DISPATCH();
CASE_CODE(STORE_FIELD_THIS):
{
int field = READ_BYTE();
Value receiver = stackStart[0];
ASSERT(IS_INSTANCE(receiver), "Receiver should be instance.");
ObjInstance* instance = AS_INSTANCE(receiver);
ASSERT(field < instance->obj.classObj->numFields, "Out of bounds field.");
instance->fields[field] = PEEK();
DISPATCH();
}
CASE_CODE(LOAD_FIELD):
{
int field = READ_BYTE();
Value receiver = POP();
ASSERT(IS_INSTANCE(receiver), "Receiver should be instance.");
ObjInstance* instance = AS_INSTANCE(receiver);
ASSERT(field < instance->obj.classObj->numFields, "Out of bounds field.");
PUSH(instance->fields[field]);
DISPATCH();
}
CASE_CODE(STORE_FIELD):
{
int field = READ_BYTE();
Value receiver = POP();
ASSERT(IS_INSTANCE(receiver), "Receiver should be instance.");
ObjInstance* instance = AS_INSTANCE(receiver);
ASSERT(field < instance->obj.classObj->numFields, "Out of bounds field.");
instance->fields[field] = PEEK();
DISPATCH();
}
CASE_CODE(JUMP):
{
int offset = READ_SHORT();
ip += offset;
DISPATCH();
}
CASE_CODE(LOOP):
{
// Jump back to the top of the loop.
int offset = READ_SHORT();
ip -= offset;
DISPATCH();
}
CASE_CODE(JUMP_IF):
{
int offset = READ_SHORT();
Value condition = POP();
if (IS_FALSE(condition) || IS_NULL(condition)) ip += offset;
DISPATCH();
}
CASE_CODE(AND):
{
int offset = READ_SHORT();
Value condition = PEEK();
if (IS_FALSE(condition) || IS_NULL(condition))
{
// Short-circuit the right hand side.
ip += offset;
}
else
{
// Discard the condition and evaluate the right hand side.
DROP();
}
DISPATCH();
}
CASE_CODE(OR):
{
int offset = READ_SHORT();
Value condition = PEEK();
if (IS_FALSE(condition) || IS_NULL(condition))
{
// Discard the condition and evaluate the right hand side.
DROP();
}
else
{
// Short-circuit the right hand side.
ip += offset;
}
DISPATCH();
}
CASE_CODE(IS):
{
Value expected = POP();
if (!IS_CLASS(expected))
{
const char* message = "Right operand must be a class.";
RUNTIME_ERROR(AS_STRING(wrenNewString(vm, message, strlen(message))));
}
ObjClass* actual = wrenGetClass(vm, POP());
bool isInstance = false;
// Walk the superclass chain looking for the class.
while (actual != NULL)
{
if (actual == AS_CLASS(expected))
{
isInstance = true;
break;
}
actual = actual->superclass;
}
PUSH(BOOL_VAL(isInstance));
DISPATCH();
}
CASE_CODE(CLOSE_UPVALUE):
closeUpvalue(fiber);
DROP();
DISPATCH();
CASE_CODE(RETURN):
{
Value result = POP();
fiber->numFrames--;
// Close any upvalues still in scope.
Value* firstValue = stackStart;
while (fiber->openUpvalues != NULL &&
fiber->openUpvalues->value >= firstValue)
{
closeUpvalue(fiber);
}
// If the fiber is complete, end it.
if (fiber->numFrames == 0)
{
// If this is the main fiber, we're done.
if (fiber->caller == NULL) return true;
// We have a calling fiber to resume.
fiber = fiber->caller;
// Store the result in the resuming fiber.
*(fiber->stackTop - 1) = result;
}
else
{
// Store the result of the block in the first slot, which is where the
// caller expects it.
stackStart[0] = result;
// Discard the stack slots for the call frame (leaving one slot for the
// result).
fiber->stackTop = frame->stackStart + 1;
}
LOAD_FRAME();
DISPATCH();
}
CASE_CODE(LIST):
{
int numElements = READ_BYTE();
ObjList* list = wrenNewList(vm, numElements);
// TODO: Do a straight memcopy.
for (int i = 0; i < numElements; i++)
{
list->elements[i] = *(fiber->stackTop - numElements + i);
}
// Discard the elements.
fiber->stackTop -= numElements;
PUSH(OBJ_VAL(list));
DISPATCH();
}
CASE_CODE(CLOSURE):
{
ObjFn* prototype = AS_FN(fn->constants[READ_SHORT()]);
ASSERT(prototype->numUpvalues > 0,
"Should not create closure for functions that don't need it.");
// Create the closure and push it on the stack before creating upvalues
// so that it doesn't get collected.
ObjClosure* closure = wrenNewClosure(vm, prototype);
PUSH(OBJ_VAL(closure));
// Capture upvalues.
for (int i = 0; i < prototype->numUpvalues; i++)
{
bool isLocal = READ_BYTE();
int index = READ_BYTE();
if (isLocal)
{
// Make an new upvalue to close over the parent's local variable.
closure->upvalues[i] = captureUpvalue(vm, fiber,
frame->stackStart + index);
}
else
{
// Use the same upvalue as the current call frame.
closure->upvalues[i] = ((ObjClosure*)frame->fn)->upvalues[index];
}
}
DISPATCH();
}
CASE_CODE(CLASS):
{
ObjString* name = AS_STRING(PEEK2());
ObjClass* superclass;
if (IS_NULL(PEEK()))
{
// Implicit Object superclass.
superclass = vm->objectClass;
}
else
{
// TODO: Handle the superclass not being a class object!
superclass = AS_CLASS(PEEK());
}
int numFields = READ_BYTE();
ObjClass* classObj = wrenNewClass(vm, superclass, numFields, name);
// Don't pop the superclass and name off the stack until the subclass is
// done being created, to make sure it doesn't get collected.
DROP();
DROP();
// Now that we know the total number of fields, make sure we don't
// overflow.
if (superclass->numFields + numFields > MAX_FIELDS)
{
char message[70 + MAX_VARIABLE_NAME];
snprintf(message, 70 + MAX_VARIABLE_NAME,
"Class '%s' may not have more than %d fields, including inherited "
"ones.", name->value, MAX_FIELDS);
RUNTIME_ERROR(AS_STRING(wrenNewString(vm, message, strlen(message))));
}
PUSH(OBJ_VAL(classObj));
DISPATCH();
}
CASE_CODE(METHOD_INSTANCE):
CASE_CODE(METHOD_STATIC):
{
int type = instruction;
int symbol = READ_SHORT();
ObjClass* classObj = AS_CLASS(PEEK());
Value method = PEEK2();
bindMethod(vm, type, symbol, classObj, method);
DROP();
DROP();
DISPATCH();
}
CASE_CODE(END):
// A CODE_END should always be preceded by a CODE_RETURN. If we get here,
// the compiler generated wrong code.
UNREACHABLE();
}
// We should only exit this function from an explicit return from CODE_RETURN
// or a runtime error.
UNREACHABLE();
return false;
}
WrenInterpretResult wrenInterpret(WrenVM* vm, const char* sourcePath,
const char* source)
{
// TODO: Check for freed VM.
ObjFn* fn = wrenCompile(vm, sourcePath, source);
if (fn == NULL) return WREN_RESULT_COMPILE_ERROR;
WREN_PIN(vm, fn);
vm->fiber = wrenNewFiber(vm, (Obj*)fn);
WREN_UNPIN(vm);
if (runInterpreter(vm))
{
return WREN_RESULT_SUCCESS;
}
else
{
return WREN_RESULT_RUNTIME_ERROR;
}
}
static void string()
{
emit_constant(OBJ_VAL(copy_string(parser.previous.start + 1, parser.previous.length - 2)));
}
