objc-runtime.h   [plain text]


/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 *	objc-runtime.h
 *	Copyright 1988-1996, NeXT Software, Inc.
 */

#ifndef _OBJC_RUNTIME_H_
#define _OBJC_RUNTIME_H_

#import <stdarg.h>
#import <AvailabilityMacros.h>
#import <objc/objc.h>
#import <objc/objc-class.h>

#if !defined(AVAILABLE_MAC_OS_X_VERSION_10_3_AND_LATER)
    /* For 10.2 compatibility */
#   define AVAILABLE_MAC_OS_X_VERSION_10_3_AND_LATER
#endif

typedef struct objc_symtab *Symtab;

struct objc_symtab {
	unsigned long 	sel_ref_cnt;
	SEL 		*refs;		
	unsigned short 	cls_def_cnt;
	unsigned short 	cat_def_cnt;
	void  		*defs[1];	/* variable size */
};

typedef struct objc_module *Module;

struct objc_module {
	unsigned long	version;
	unsigned long	size;
	const char	*name;
	Symtab 		symtab;	
};

struct objc_super {
	id receiver;
#ifndef __cplusplus
	Class class;
#else
	Class super_class;
#endif
};

/*
 * Messaging Primitives (prototypes)
 */

OBJC_EXPORT id objc_getClass(const char *name);
OBJC_EXPORT id objc_getMetaClass(const char *name);
OBJC_EXPORT id objc_msgSend(id self, SEL op, ...);
OBJC_EXPORT id objc_msgSendSuper(struct objc_super *super, SEL op, ...);


/* Floating-point-returning Messaging Primitives (prototypes)
 * 
 * On some platforms, the ABI for functions returning a floating-point 
 * value is incompatible with that for functions returning an integral type. 
 * objc_msgSend_fpret must be used for these. 
 * 
 * ppc: objc_msgSend_fpret not used
 * ppc64: objc_msgSend_fpret not used
 * i386: objc_msgSend_fpret REQUIRED
 *
 * For `float` or `long double` return types, cast the function 
 * to an appropriate function pointer type first.
 */

#ifdef __i386__
OBJC_EXPORT double objc_msgSend_fpret(id self, SEL op, ...);
#endif


/* Struct-returning Messaging Primitives (prototypes)
 *
 * For historical reasons, the prototypes for the struct-returning 
 * messengers are unusual. The portable, correct way to call these functions 
 * is to cast them to your desired return type first.
 * 
 * For example, `NSRect result = [myNSView frame]` could be written as:
 *   NSRect (*msgSend_stret_fn)(id, SEL, ...) = (NSRect(*)(id, SEL, ...))objc_msgSend_stret;
 *   NSRect result = (*msgSend_stret_fn)(myNSView, @selector(frame));
 * or, without the function pointer:
 *   NSRect result = (*(NSRect(*)(id, SEL, ...))objc_msgSend_stret)(myNSView, @selector(frame));
 * 
 * BE WARNED that these prototypes have changed in the past and will change 
 * in the future. Code that uses a cast like the example above will be 
 * unaffected. 
 */

#if defined(__cplusplus)
  OBJC_EXPORT id objc_msgSend_stret(id self, SEL op, ...);
  OBJC_EXPORT id objc_msgSendSuper_stret(struct objc_super *super, SEL op, ...);
#else
  OBJC_EXPORT void objc_msgSend_stret(void * stretAddr, id self, SEL op, ...);
  OBJC_EXPORT void objc_msgSendSuper_stret(void * stretAddr, struct objc_super *super, SEL op, ...);
#endif


/* Forwarding */

OBJC_EXPORT id objc_msgSendv(id self, SEL op, unsigned arg_size, marg_list arg_frame);
OBJC_EXPORT void objc_msgSendv_stret(void * stretAddr, id self, SEL op, unsigned arg_size, marg_list arg_frame);

/* 
    getting all the classes in the application...
    
    int objc_getClassList(buffer, bufferLen)
	classes is an array of Class values (which are pointers)
		which will be filled by the function; if this
		argument is NULL, no copying is done, only the
		return value is returned
	bufferLen is the number of Class values the given buffer
		can hold; if the buffer is not large enough to
		hold all the classes, the buffer is filled to
		the indicated capacity with some arbitrary subset
		of the known classes, which could be different
		from call to call
	returns the number of classes, which is the number put
		in the buffer if the buffer was large enough,
		or the length the buffer should have been

    int numClasses = 0, newNumClasses = objc_getClassList(NULL, 0);
    Class *classes = NULL;
    while (numClasses < newNumClasses) {
        numClasses = newNumClasses;
        classes = realloc(classes, sizeof(Class) * numClasses);
        newNumClasses = objc_getClassList(classes, numClasses);
    }
    // now, can use the classes list; if NULL, there are no classes
    free(classes);

*/
OBJC_EXPORT int objc_getClassList(Class *buffer, int bufferLen);

#define OBSOLETE_OBJC_GETCLASSES 1
#if OBSOLETE_OBJC_GETCLASSES
OBJC_EXPORT void *objc_getClasses(void);
#endif

OBJC_EXPORT id objc_lookUpClass(const char *name);
OBJC_EXPORT id objc_getRequiredClass(const char *name);
OBJC_EXPORT void objc_addClass(Class myClass);

/* customizing the error handling for objc_getClass/objc_getMetaClass */

OBJC_EXPORT void objc_setClassHandler(int (*)(const char *));

/* Making the Objective-C runtime thread safe. */
OBJC_EXPORT void objc_setMultithreaded (BOOL flag);

/* overriding the default object allocation and error handling routines */

OBJC_EXPORT id	(*_alloc)(Class, unsigned int);
OBJC_EXPORT id	(*_copy)(id, unsigned int);
OBJC_EXPORT id	(*_realloc)(id, unsigned int);
OBJC_EXPORT id	(*_dealloc)(id);
OBJC_EXPORT id	(*_zoneAlloc)(Class, unsigned int, void *);
OBJC_EXPORT id	(*_zoneRealloc)(id, unsigned int, void *);
OBJC_EXPORT id	(*_zoneCopy)(id, unsigned int, void *);

OBJC_EXPORT void	(*_error)(id, const char *, va_list);


#endif /* _OBJC_RUNTIME_H_ */