[apple/libc.git] / sys / crt_externs.c

/*
 * 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@
 */
/*
** This file contains interfaces to the symbols defined int the crt modules.
** 3 April 1995
** Matt Watson (mwatson@next.com)
**
*/

#if defined(__DYNAMIC__)
#include "mach-o/dyld.h" /* defines _dyld_lookup_and_bind() */
#define STRINGIFY(a) # a
#define DECLARE_VAR(var, type)					\
        static type * var ## _pointer = 0
#define DECLARE_PROGNAME(var, type)				\
        static type * var ## _pointer = 0;			\
        static type _priv_ ## var = 0
#define SETUP_VAR(var)						\
    if ( var ## _pointer == 0) {				\
        _dyld_lookup_and_bind( STRINGIFY(_ ## var),		\
                (unsigned long *) & var ## _pointer, 0);	\
    }
#define SETUP_PROGNAME(var)					\
    if ( var ## _pointer == 0) {				\
	if(NSIsSymbolNameDefined( STRINGIFY(_ ## var) ))	\
	    _dyld_lookup_and_bind( STRINGIFY(_ ## var),		\
                (unsigned long *) & var ## _pointer, 0);	\
	else {							\
	    char *progname = _dyld_get_image_name(0);		\
	    if(_priv_ ## var = strrchr(progname, '/'))		\
		_priv_ ## var ++;				\
	    else						\
		_priv_ ## var = progname;			\
	    var ## _pointer = & _priv_ ## var;			\
	}							\
    }
#define USE_VAR(var) (var ## _pointer)
#else
#define DECLARE_VAR(var, type) extern type var
#define DECLARE_PROGNAME(var, type) DECLARE_VAR(var, type)
#define SETUP_VAR(var)
#define SETUP_PROGNAME(var) SETUP_VAR(var)
#define USE_VAR(var) (& var)
#endif

char ***_NSGetArgv(void) {
    DECLARE_VAR(NXArgv, char **);
    SETUP_VAR(NXArgv);
    return(USE_VAR(NXArgv));
}

int *_NSGetArgc(void) {
    DECLARE_VAR(NXArgc, int);
    SETUP_VAR(NXArgc);
    return(USE_VAR(NXArgc));
}

char ***_NSGetEnviron(void) {
    DECLARE_VAR(environ, char **);
    SETUP_VAR(environ);
    return(USE_VAR(environ));
}

char **_NSGetProgname(void) {
    DECLARE_PROGNAME(__progname, char *);
    SETUP_PROGNAME(__progname);
    return(USE_VAR(__progname));
}

struct mach_header *_NSGetMachExecuteHeader(void) {
    DECLARE_VAR(_mh_execute_header, struct mach_header);
    SETUP_VAR(_mh_execute_header);
    return(USE_VAR(_mh_execute_header));
}

/*
 * Fix for Radar bug 2200596 --
 * EH symbol definitions for gcc 2.7.2.x implementation of
 * C++ exception handling.  The problem:  the EH implementation
 * has "throw" store stuff into these pointers, and then as the
 * stack is unwound, the code generated into each function (for
 * checking whether this function contains a relevant "catch"
 * clause and for calling destructors for local variables) looks
 * at these globals to find the type and value thrown.
 *
 * The problem was that the compiler generated the symbols as
 * "common" symbols, and common symbols cannot be placed in
 * dynamic shared libraries.  So we must put these guys as
 * "data" symbols into crt0.o or the System Framework (library),
 * and the compiler must generate code that defines the symbols
 * as external references instead of common.
 *
 * I changed the symbol names (added the "_272") to be utterly
 * paranoid about any possible future use of similar names by
 * any future versions of gcc.
 *                      -- D. Landauer, Jan. 1998
 */

void *__eh_pc_gcc_272 = (void *)0;
void *__eh_type_gcc_272 = (void *)0;
void *__eh_value_gcc_272 = (void *)0;

/* This is what egcs uses for its global data pointer */
void *__eh_global_dataptr = (void *)0;
Commit	Line	Data
e9ce8d39 A	1	/*
	2	* Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
734aad71	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
e9ce8d39	7	*
734aad71 A	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
e9ce8d39 A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
e9ce8d39 A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
734aad71 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
e9ce8d39 A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/*
	26	** This file contains interfaces to the symbols defined int the crt modules.
	27	** 3 April 1995
	28	** Matt Watson (mwatson@next.com)
	29	**
	30	*/
	31
	32	#if defined(__DYNAMIC__)
	33	#include "mach-o/dyld.h" /* defines _dyld_lookup_and_bind() */
	34	#define STRINGIFY(a) # a
9385eb3d	35	#define DECLARE_VAR(var, type) \
e9ce8d39	36	static type * var ## _pointer = 0
9385eb3d A	37	#define DECLARE_PROGNAME(var, type) \
	38	static type * var ## _pointer = 0; \
	39	static type _priv_ ## var = 0
e9ce8d39 A	40	#define SETUP_VAR(var) \
	41	if ( var ## _pointer == 0) { \
	42	_dyld_lookup_and_bind( STRINGIFY(_ ## var), \
	43	(unsigned long *) & var ## _pointer, 0); \
	44	}
9385eb3d A	45	#define SETUP_PROGNAME(var) \
	46	if ( var ## _pointer == 0) { \
	47	if(NSIsSymbolNameDefined( STRINGIFY(_ ## var) )) \
	48	_dyld_lookup_and_bind( STRINGIFY(_ ## var), \
	49	(unsigned long *) & var ## _pointer, 0); \
	50	else { \
	51	char *progname = _dyld_get_image_name(0); \
	52	if(_priv_ ## var = strrchr(progname, '/')) \
	53	_priv_ ## var ++; \
	54	else \
	55	_priv_ ## var = progname; \
	56	var ## _pointer = & _priv_ ## var; \
	57	} \
	58	}
e9ce8d39 A	59	#define USE_VAR(var) (var ## _pointer)
	60	#else
	61	#define DECLARE_VAR(var, type) extern type var
9385eb3d	62	#define DECLARE_PROGNAME(var, type) DECLARE_VAR(var, type)
e9ce8d39	63	#define SETUP_VAR(var)
9385eb3d	64	#define SETUP_PROGNAME(var) SETUP_VAR(var)
e9ce8d39 A	65	#define USE_VAR(var) (& var)
	66	#endif
	67
	68	char ***_NSGetArgv(void) {
	69	DECLARE_VAR(NXArgv, char **);
	70	SETUP_VAR(NXArgv);
	71	return(USE_VAR(NXArgv));
	72	}
	73
	74	int *_NSGetArgc(void) {
	75	DECLARE_VAR(NXArgc, int);
	76	SETUP_VAR(NXArgc);
	77	return(USE_VAR(NXArgc));
	78	}
	79
	80	char ***_NSGetEnviron(void) {
	81	DECLARE_VAR(environ, char **);
	82	SETUP_VAR(environ);
	83	return(USE_VAR(environ));
	84	}
	85
5b2abdfb	86	char **_NSGetProgname(void) {
9385eb3d A	87	DECLARE_PROGNAME(__progname, char *);
9385eb3d A	88	SETUP_PROGNAME(__progname);
5b2abdfb A	89	return(USE_VAR(__progname));
	90	}
	91
e9ce8d39 A	92	struct mach_header *_NSGetMachExecuteHeader(void) {
	93	DECLARE_VAR(_mh_execute_header, struct mach_header);
	94	SETUP_VAR(_mh_execute_header);
	95	return(USE_VAR(_mh_execute_header));
	96	}
	97
	98	/*
	99	* Fix for Radar bug 2200596 --
	100	* EH symbol definitions for gcc 2.7.2.x implementation of
	101	* C++ exception handling. The problem: the EH implementation
	102	* has "throw" store stuff into these pointers, and then as the
	103	* stack is unwound, the code generated into each function (for
	104	* checking whether this function contains a relevant "catch"
	105	* clause and for calling destructors for local variables) looks
	106	* at these globals to find the type and value thrown.
	107	*
	108	* The problem was that the compiler generated the symbols as
	109	* "common" symbols, and common symbols cannot be placed in
	110	* dynamic shared libraries. So we must put these guys as
	111	* "data" symbols into crt0.o or the System Framework (library),
	112	* and the compiler must generate code that defines the symbols
	113	* as external references instead of common.
	114	*
	115	* I changed the symbol names (added the "_272") to be utterly
	116	* paranoid about any possible future use of similar names by
	117	* any future versions of gcc.
	118	* -- D. Landauer, Jan. 1998
	119	*/
	120
	121	void __eh_pc_gcc_272 = (void )0;
	122	void __eh_type_gcc_272 = (void )0;
	123	void __eh_value_gcc_272 = (void )0;
	124
	125	/* This is what egcs uses for its global data pointer */
	126	void __eh_global_dataptr = (void )0;