path: root/Modules/objc.c

/***********************************************************
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
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documentation for any purpose and without fee is hereby granted, 
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******************************************************************/

/* Objective-C interface for NeXTStep */
/* Tested with NeXTStep 3.3 on Intel and Sparc architectures */

/* Original author: Jon M. Kutemeier */
/* Revamped and maintained by: Guido van Rossum */

/* XXX To do:
   - bug??? x.send('name', []) gives weird error
   - rename functions from objc_* to ObjC_*
   - change send(sel, [a, b, c]) to send(self, a, b, c)
   - call back to Python from Objective-C
 */

/* Python header file */
#include "Python.h"

/* NeXT headers */
#include <sys/param.h>
#include <mach-o/rld.h>
#include <objc/objc.h>
#include <objc/objc-runtime.h>
#import <remote/NXProxy.h>

/* Distinguish between ObjC classes and instances */
typedef enum {
    OBJC_CLASS,
    OBJC_INSTANCE,
} ObjC_Typecode;

/* Exception raised for ObjC specific errors */
static PyObject *ObjC_Error;

/* Python wrapper about ObjC id (instance or class) */
typedef struct {
    PyObject_HEAD
    id             obj;
    ObjC_Typecode  type;
    int            owned;
} ObjCObject;

/* Corresponding Python type object */
staticforward PyTypeObject ObjC_Type;

/* Corresponding Python type check macro */
#define ObjC_Check(o) ((o)->ob_type == &ObjC_Type)

/* Create a new ObjCObject */
static ObjCObject *
newObjCObject(obj, type, owned)
    id obj;
    ObjC_Typecode type;
    int owned;
{
    ObjCObject *self;

    self = PyObject_NEW(ObjCObject, &ObjC_Type);
    if (self == NULL)
	return NULL;

    self->obj = obj;
    self->type = type;
    self->owned = owned;

    return self;
}

static void
objc_sendfree(self)
    ObjCObject *self;
{
    if (self->obj)
	self->obj = (id)objc_msgSend(self->obj, SELUID("free"));
}

/* Deallocate an ObjCObject */
static void
objc_dealloc(self)
    ObjCObject *self;
{
    if (self->owned)
	objc_sendfree(self);
    PyMem_DEL(self);
}

/* Return a string representation of an ObjCObject */
static PyObject *
objc_repr(self)
    ObjCObject *self;
{
    char buffer[512];
    char *p = buffer;
    if (self->obj == nil)
	p = "<Objective-C nil>";
    else {
	char *t;
	switch (self->type) {
	case OBJC_CLASS: t = "class"; break;
	case OBJC_INSTANCE: t = "instance"; break;
	default: t = "???"; break;
	}
	sprintf(buffer, "<Objective-C %s %s at %lx>",
		NAMEOF(self->obj), t, (long)(self->obj));
    }
    return PyString_FromString(p);
}

/*** ObjCObject methods ***/

/* Call an object's free method */
static PyObject *
objc_free(self, args)
    ObjCObject *self;
    PyObject *args;
{
    if (!PyArg_ParseTuple(args, ""))
	return NULL;
    objc_sendfree(self);
}

/* Send a message to an ObjCObject.
   The Python call looks like e.g. obj.send('moveTo::', [arg1, arg2])
   which translates into Objective-C as [obj moveTo: arg1 : arg2] */
static PyObject *
objc_send(self, args)
    ObjCObject *self;
    PyObject *args;
{
    char *methodname;
    char *margBuff = NULL;
    PyObject *retobject = NULL;
    PyObject *arglist;
    id receiver, obj;
    char *type;
    SEL sel;
    Method meth;
    unsigned int margCount, margSize;
    int offset, i;

    if (!PyArg_ParseTuple(args, "sO!", &methodname, &PyList_Type, &arglist))
	return NULL;

    /* Get the method descriptor from the object */

    receiver = self->obj;
    sel = SELUID(methodname);

    switch(self->type) {
    case OBJC_CLASS:
	meth = class_getClassMethod(receiver->isa, sel);
	break;
    case OBJC_INSTANCE:
	meth = class_getInstanceMethod(receiver->isa, sel);
	break;
    default:
	PyErr_SetString(ObjC_Error,
			"receiver's type is neither instance not class!?!?");
	return NULL;
    }

    if (!meth) {
	PyErr_SetString(ObjC_Error, "receiver has no method by that name");
	return NULL;
    }

    /* Fill in the argument list, type-checking the arguments */

    margCount = method_getNumberOfArguments(meth);

    if (PyList_Size(arglist) + 2 != margCount) {
	PyErr_SetString(ObjC_Error,
			"wrong number of arguments for this method");
	    return NULL;
    }

    margSize = method_getSizeOfArguments(meth);
    margBuff = PyMem_NEW(char, margSize+1);
    if (margBuff == NULL)
	return PyErr_NoMemory();

    method_getArgumentInfo(meth, 0, &type, &offset);
    marg_setValue(margBuff, offset, id, receiver);

    method_getArgumentInfo(meth, 1, &type, &offset);
    marg_setValue(margBuff, offset, SEL, sel);

    for (i = 2; i < margCount; i++) {
	PyObject *argument;
	method_getArgumentInfo(meth, i, &type, &offset);

	argument = PyList_GetItem(arglist, i-2);

	/* scan past protocol-type modifiers */
	while (strchr("rnNoOV", *type) != 0)
	    type++;

	/* common type checks */
	switch(*type) {

	    /* XXX The errors here should point out which argument */

	case 'c':
	case '*':
	case 'C':
	    if (!PyString_Check(argument)) {
		PyErr_SetString(ObjC_Error, "string argument expected");
		goto error;
	    }
	    break;

	case 'i':
	case 's':
	case 'I':
	case 'S':
	case 'l':
	case 'L':
	case '^':
	    if (!PyInt_Check(argument)) {
		PyErr_SetString(ObjC_Error, "integer argument expected");
		goto error;
	    }
	    break;

	case 'f':
	case 'd':
	    if (!PyFloat_Check(argument)) {
		PyErr_SetString(ObjC_Error, "float argument expected");
		goto error;
	    }
	    break;

	}

	/* convert and store the argument */
	switch (*type) {

	case 'c': /* char */
	    marg_setValue(margBuff, offset, char,
			  PyString_AsString(argument)[0]);
	    break;

	case 'C': /* unsigned char */
	    marg_setValue(margBuff, offset, unsigned char,
			  PyString_AsString(argument)[0]);
	    break;

	case '*': /* string */
	    marg_setValue(margBuff, offset, char *,
			  PyString_AsString(argument));
	    break;

	case 'i': /* int */
	    marg_setValue(margBuff, offset, int,
			  PyInt_AsLong(argument));
	    break;

	case 'I': /* unsigned int */
	    marg_setValue(margBuff, offset, unsigned int,
			  PyInt_AsLong(argument));
	    break;

	case 's': /* short */
	    marg_setValue(margBuff, offset, short,
			  PyInt_AsLong(argument));
	    break;

	case 'S': /* unsigned short */
	    marg_setValue(margBuff, offset, unsigned short,
			  PyInt_AsLong(argument));
	    break;

	case 'l': /* long */
	    marg_setValue(margBuff, offset, long,
			  PyInt_AsLong(argument));
	    break;

	case 'L': /* unsigned long */
	    marg_setValue(margBuff, offset, unsigned long,
			  PyInt_AsLong(argument));
	    break;

	case 'f': /* float */
	    marg_setValue(margBuff, offset, float,
			  (float)PyFloat_AsDouble(argument));
	    break;

	case 'd': /* double */
	    marg_setValue(margBuff, offset, double,
			  PyFloat_AsDouble(argument));
	    break;

	case '@': /* id (or None) */
	    if (ObjC_Check(argument))
		marg_setValue(margBuff, offset, id,
			      ((ObjCObject *)(argument))->obj);
	    else if (argument == Py_None)
		marg_setValue(margBuff, offset, id, nil);
	    else {
		PyErr_SetString(ObjC_Error, "id or None argument expected");
		goto error;
	    }
	    break;

	case '^': /* void * (use int) */
	    marg_setValue(margBuff, offset, void *,
			  (void *)PyInt_AsLong(argument));
	    break;

	case ':': /* SEL (use string or int) */
	    if (PyInt_Check(argument))
		marg_setValue(margBuff, offset, SEL,
			      (SEL)PyInt_AsLong(argument));
	    else if (PyString_Check(argument))
		marg_setValue(margBuff, offset, SEL,
			      SELUID(PyString_AsString(argument)));
	    else {
		PyErr_SetString(ObjC_Error,
				"selector string or int argument expected");
		goto error;
	    }
	    break;

	case '#': /* Class (may also use int) */
	    if (ObjC_Check(argument) &&
		((ObjCObject *)argument)->type == OBJC_INSTANCE)
		marg_setValue(margBuff, offset, Class *,
			      (Class *)((ObjCObject *)argument)->obj);
	    else if (PyInt_Check(argument))
		marg_setValue(margBuff, offset, Class *,
			      (Class *)PyInt_AsLong(argument));
	    else {
		PyErr_SetString(ObjC_Error,
				"ObjC class object required");
		goto error;
	    }
	    break;

	default:
	    PyErr_SetString(ObjC_Error, "unknown argument type");
	    goto error;

	}
    }

    /* Call the method and set the return value */

    type = meth->method_types;

    while (strchr("rnNoOV", *type))
	type++;

    switch(*type) {

/* Cast objc_msgSendv to a function returning the right thing */
#define MS_CAST(type) ((type (*)())objc_msgSendv)

    case 'c':
    case '*':
    case 'C':
	retobject = (PyObject *)PyString_FromString(
	    MS_CAST(char *)(receiver, sel, margSize, margBuff));
	break;

    case 'i':
    case 's':
    case 'I':
    case 'S':
	retobject = (PyObject *)PyInt_FromLong(
	    MS_CAST(int)(receiver, sel, margSize, margBuff));
	break;

    case 'l':
    case 'L':
    case '^':
	retobject = (PyObject *)PyInt_FromLong(
	    MS_CAST(long)(receiver, sel, margSize, margBuff));
	break;

    case 'f':
	retobject = (PyObject *)PyFloat_FromDouble(
	    MS_CAST(float)(receiver, sel, margSize, margBuff));
	break;

    case 'd':
	retobject = (PyObject *)PyFloat_FromDouble(
	    MS_CAST(double)(receiver, sel, margSize, margBuff));
	break;

    case '@':
	obj = MS_CAST(id)(receiver, sel, margSize, margBuff);
	if (obj == nil) {
	    retobject = Py_None;
	    Py_INCREF(retobject);
	}
	else if (obj != receiver)
	    retobject = (PyObject *)newObjCObject(obj, OBJC_INSTANCE, 0);
	else {
	    retobject = (PyObject *)self;
	    Py_INCREF(retobject);
	}
	break;

    case ':':
	retobject = (PyObject *)PyInt_FromLong(
	    (long)MS_CAST(SEL)(receiver, sel, margSize, margBuff));
	break;

    case '#':
	retobject = (PyObject *)PyInt_FromLong(
	    (long)MS_CAST(Class *)(receiver, sel, margSize, margBuff));
	break;

#undef MS_CAST

    }

  error:
    PyMem_XDEL(margBuff);
    return retobject;
}

/* List of methods for ObjCObject */
static PyMethodDef objc_methods[] = {
    {"send",	(PyCFunction)objc_send, 1},
    {"free",	(PyCFunction)objc_free, 1},
    {NULL,	NULL}		/* sentinel */
};

/* Get an attribute of an ObjCObject */
static PyObject *
objc_getattr(self, name)
    ObjCObject *self;
    char *name;
{
    PyObject *method;

    /* Try a function method */
    method = Py_FindMethod(objc_methods, (PyObject *)self, name);
    if (method != NULL)
	return method;
    PyErr_Clear();

    /* Try an instance variable */
    if (strcmp(name, "obj") == 0)
	return PyInt_FromLong((long)self->obj);
    if (strcmp(name, "type") == 0)
	return PyInt_FromLong((long)self->type);
    if (strcmp(name, "owned") == 0)
	return PyInt_FromLong((long)self->owned);
    if (strcmp(name, "name") == 0)
	return PyString_FromString(NAMEOF(self->obj));
    if (strcmp(name, "__members__") == 0)
	return Py_BuildValue("[sss]", "name", "obj", "owned", "type");

    PyErr_SetString(PyExc_AttributeError, name);
    return NULL;
}

/* The type object */
static PyTypeObject ObjC_Type = {
    PyObject_HEAD_INIT(&PyType_Type)
    0,                                  /*ob_size*/
    "objc",                             /*tp_name*/
    sizeof(ObjCObject),                 /*tp_basicsize*/
    0,                                  /*tp_itemsize*/
    /* methods */
    (destructor)objc_dealloc,           /*tp_dealloc*/
    0,                         		/*tp_print*/
    (getattrfunc)objc_getattr,          /*tp_getattr*/
    0,                       		/*tp_setattr*/
    0,                         		/*tp_compare*/
    (reprfunc)objc_repr,		/*tp_repr*/
    0,                                  /*tp_as_number*/
    0,                                  /*tp_as_sequence*/
    0,                                  /*tp_as_mapping*/
    0,     		                /*tp_hash*/
    0,					/*tp_call*/
    0,					/*tp_str*/
    0, 0, 0, 0,				/*xxx1-4*/
    "Objective-C id wrapper",		/*tp_doc*/
};



/*** Top-level functions ***/

/* Max #files passed to loadobjectfile() */
#define MAXRLD 128

/* Load a list of object files */
static PyObject *
objc_loadobjectfiles(self, args)
PyObject *self;   /* Not used */
PyObject *args;
{
    NXStream *errorStream;
    struct mach_header *new_header;
    const char *filenames[MAXRLD+1];
    long ret;
    char *streamBuf;
    PyObject *filelist, *file;
    int listsize, len, maxLen, i;

    if (!PyArg_ParseTuple(args, "O!", &PyList_Type, &filelist))
	return NULL;

    listsize = PyList_Size(filelist);

    if (listsize > MAXRLD) {
	PyErr_SetString(ObjC_Error, "more than 128 files in list");
	return NULL;
    }

    errorStream = NXOpenMemory(NULL, 0, NX_WRITEONLY);

    for (i = 0; i < listsize; i++) {
	file = PyList_GetItem(filelist, i);

	if (!PyString_Check(file))
	    {
		PyErr_SetString(ObjC_Error,
				"all list items must be strings");
		return NULL;
	    }

	filenames[i] = PyString_AsString(file);
    }

    filenames[listsize] = NULL;

    ret = objc_loadModules(filenames, errorStream, NULL, &new_header, NULL);

    /* extract the error messages for the exception */

    if(ret) {
	NXPutc(errorStream, (char)0);

	NXGetMemoryBuffer(errorStream, &streamBuf, &len, &maxLen);
	PyErr_SetString(ObjC_Error, streamBuf);
    }

    NXCloseMemory(errorStream, NX_FREEBUFFER);

    if(ret)
	return NULL;

    Py_XINCREF(Py_None);
    return Py_None;
}

static PyObject *
objc_lookupclass(self, args)
PyObject *self;   /* Not used */
PyObject *args;
{
    char *classname;
    id    class;

    if (!PyArg_ParseTuple(args, "s", &classname))
	return NULL;

    if (!(class = objc_lookUpClass(classname)))
	{
	    PyErr_SetString(ObjC_Error, "unknown ObjC class");
	    return NULL;
	}

    return (PyObject *)newObjCObject(class, OBJC_CLASS, 0);
}

/* List all classes */
static PyObject *
objc_listclasses(self, args)
    ObjCObject *self;
    PyObject *args;
{
    NXHashTable *class_hash = objc_getClasses();
    NXHashState state = NXInitHashState(class_hash);
    Class classid;
    PyObject *list;

    if (!PyArg_ParseTuple(args, ""))
	return NULL;

    list = PyList_New(0);
    if (list == NULL)
	return NULL;
  
    while (NXNextHashState(class_hash, &state, (void**)&classid)) {
	ObjCObject *item = newObjCObject(classid, OBJC_CLASS, 0);
	if (item == NULL || PyList_Append(list, (PyObject *)item) < 0) {
	    Py_XDECREF(item);
	    Py_DECREF(list);
	    return NULL;
	}
	Py_INCREF(item);
    }

    return list;
}

/* List of top-level functions */
static PyMethodDef objc_class_methods[] = {
    {"loadobjectfiles",	objc_loadobjectfiles, 1},
    {"lookupclass", 	objc_lookupclass, 1},
    {"listclasses",	objc_listclasses, 1},
    {NULL, 		NULL}		/* sentinel */
};

/* Initialize for the module */
void
initobjc()
{
    PyObject *m, *d;

    m = Py_InitModule("objc", objc_class_methods);
    d = PyModule_GetDict(m);

    ObjC_Error = PyString_FromString("objc.error");
    PyDict_SetItemString(d, "error", ObjC_Error);

    if (PyErr_Occurred())
	Py_FatalError("can't initialize module objc");

#ifdef WITH_THREAD
    objc_setMultithreaded(1);
#endif
}