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

/*
 * Copyright (c) 1999-2007 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * 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 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 USE_VAR(var) (var ## _pointer)
#else
#define DECLARE_VAR(var, type) extern type var
#define DECLARE_PROGNAME(var, type) DECLARE_VAR(var, type)
#define USE_VAR(var) (& var)
#endif

DECLARE_VAR(NXArgv, char **);
DECLARE_VAR(NXArgc, int);
DECLARE_VAR(environ, char **);
DECLARE_VAR(_mh_execute_header, struct mach_header);
DECLARE_PROGNAME(__progname, char *);

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

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

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

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

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

#if __DYNAMIC__
struct ProgramVars
{
    void*	mh;
    int*	NXArgcPtr;
    char***	NXArgvPtr;
    char***	environPtr;
    char**	__prognamePtr;
};


#define SUPPORT_PRE_GM_10_5_EXECUTABLES (__ppc__ || __i386__)


/*
 * dyld calls libSystem_initializer() and passes it a ProgramVars struct containing pointers to the
 * main executable's NXArg* global variables. libSystem_initializer() calls __libc_init() which calls
 * _program_vars_init() passing the ProgramVars parameter.
 */
void __attribute__((visibility("hidden")))
_program_vars_init(const struct ProgramVars* vars) {
#if SUPPORT_PRE_GM_10_5_EXECUTABLES
    // to support transitional 10.5 main executables that don't have extended __dyld section and instead call _NSSetProgramVars,  
    // don't overwrite values set by _NSSetProgramVars() 
    if ( NXArgv_pointer != NULL )
	return;
#endif
    NXArgv_pointer		= vars->NXArgvPtr;
    NXArgc_pointer		= vars->NXArgcPtr;
    environ_pointer		= vars->environPtr;
    __progname_pointer		= vars->__prognamePtr;
    _mh_execute_header_pointer	= vars->mh;
}

#if SUPPORT_PRE_GM_10_5_EXECUTABLES
/*
 * This is only called by main executables built with pre 10-5 GM crt1.10.5.o.  In those programs, 
 * there is no extended __dyld section, dyld cannot tell _program_vars_init() where the real program
 * variables are, so they get temp values and are set for real here.
 */
void _NSSetProgramVars(int* crt_argc, char*** crt_argv, char*** crt_environ, struct mach_header* crt_mh, char** crt_progname) {
    NXArgv_pointer		= crt_argv;
    NXArgc_pointer		= crt_argc;
    environ_pointer		= crt_environ;
    __progname_pointer		= crt_progname;
    _mh_execute_header_pointer	= crt_mh;
}
#endif 
#endif /* __DYNAMIC__ */

#if __ppc__
/*
 * 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;
#endif /* __ppc__ */
Commit	Line	Data
e9ce8d39	1	/*
224c7076	2	* Copyright (c) 1999-2007 Apple Inc. All rights reserved.
e9ce8d39 A	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
734aad71 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. Please obtain a copy of the License at
	10	* http://www.opensource.apple.com/apsl/ and read it before using this
	11	* file.
	12	*
	13	* The Original Code and all software distributed under the License are
	14	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
e9ce8d39 A	15	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
e9ce8d39 A	16	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
734aad71 A	17	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	18	* Please see the License for the specific language governing rights and
	19	* limitations under the License.
e9ce8d39 A	20	*
	21	* @APPLE_LICENSE_HEADER_END@
	22	*/
	23	/*
	24	** This file contains interfaces to the symbols defined int the crt modules.
	25	** 3 April 1995
	26	** Matt Watson (mwatson@next.com)
	27	**
	28	*/
	29
	30	#if defined(__DYNAMIC__)
	31	#include "mach-o/dyld.h" /* defines _dyld_lookup_and_bind() */
9385eb3d	32	#define DECLARE_VAR(var, type) \
e9ce8d39	33	static type * var ## _pointer = 0
9385eb3d A	34	#define DECLARE_PROGNAME(var, type) \
	35	static type * var ## _pointer = 0; \
	36	static type _priv_ ## var = 0
e9ce8d39 A	37	#define USE_VAR(var) (var ## _pointer)
	38	#else
	39	#define DECLARE_VAR(var, type) extern type var
9385eb3d	40	#define DECLARE_PROGNAME(var, type) DECLARE_VAR(var, type)
e9ce8d39 A	41	#define USE_VAR(var) (& var)
	42	#endif
	43
224c7076 A	44	DECLARE_VAR(NXArgv, char **);
	45	DECLARE_VAR(NXArgc, int);
	46	DECLARE_VAR(environ, char **);
	47	DECLARE_VAR(_mh_execute_header, struct mach_header);
	48	DECLARE_PROGNAME(__progname, char *);
	49
e9ce8d39	50	char ***_NSGetArgv(void) {
e9ce8d39 A	51	return(USE_VAR(NXArgv));
	52	}
	53
	54	int *_NSGetArgc(void) {
e9ce8d39 A	55	return(USE_VAR(NXArgc));
	56	}
	57
	58	char ***_NSGetEnviron(void) {
e9ce8d39 A	59	return(USE_VAR(environ));
	60	}
	61
5b2abdfb	62	char **_NSGetProgname(void) {
5b2abdfb A	63	return(USE_VAR(__progname));
	64	}
	65
e9ce8d39	66	struct mach_header *_NSGetMachExecuteHeader(void) {
e9ce8d39 A	67	return(USE_VAR(_mh_execute_header));
	68	}
	69
224c7076 A	70	#if __DYNAMIC__
	71	struct ProgramVars
	72	{
	73	void* mh;
	74	int* NXArgcPtr;
	75	char*** NXArgvPtr;
	76	char*** environPtr;
	77	char** __prognamePtr;
	78	};
	79
34e8f829 A	80
	81	#define SUPPORT_PRE_GM_10_5_EXECUTABLES (__ppc__ \|\| __i386__)
	82
	83
224c7076 A	84	/*
	85	* dyld calls libSystem_initializer() and passes it a ProgramVars struct containing pointers to the
	86	* main executable's NXArg* global variables. libSystem_initializer() calls __libc_init() which calls
	87	* _program_vars_init() passing the ProgramVars parameter.
	88	*/
	89	void __attribute__((visibility("hidden")))
	90	_program_vars_init(const struct ProgramVars* vars) {
34e8f829	91	#if SUPPORT_PRE_GM_10_5_EXECUTABLES
224c7076 A	92	// to support transitional 10.5 main executables that don't have extended __dyld section and instead call _NSSetProgramVars,
	93	// don't overwrite values set by _NSSetProgramVars()
	94	if ( NXArgv_pointer != NULL )
	95	return;
34e8f829	96	#endif
224c7076 A	97	NXArgv_pointer = vars->NXArgvPtr;
	98	NXArgc_pointer = vars->NXArgcPtr;
	99	environ_pointer = vars->environPtr;
	100	__progname_pointer = vars->__prognamePtr;
	101	_mh_execute_header_pointer = vars->mh;
	102	}
	103
34e8f829	104	#if SUPPORT_PRE_GM_10_5_EXECUTABLES
224c7076 A	105	/*
	106	* This is only called by main executables built with pre 10-5 GM crt1.10.5.o. In those programs,
	107	* there is no extended __dyld section, dyld cannot tell _program_vars_init() where the real program
	108	* variables are, so they get temp values and are set for real here.
	109	*/
	110	void _NSSetProgramVars(int* crt_argc, char* crt_argv, char* crt_environ, struct mach_header* crt_mh, char** crt_progname) {
	111	NXArgv_pointer = crt_argv;
	112	NXArgc_pointer = crt_argc;
	113	environ_pointer = crt_environ;
	114	__progname_pointer = crt_progname;
	115	_mh_execute_header_pointer = crt_mh;
	116	}
34e8f829 A	117	#endif
34e8f829 A	118	#endif /* __DYNAMIC__ */
224c7076	119
34e8f829	120	#if __ppc__
e9ce8d39 A	121	/*
	122	* Fix for Radar bug 2200596 --
	123	* EH symbol definitions for gcc 2.7.2.x implementation of
	124	* C++ exception handling. The problem: the EH implementation
	125	* has "throw" store stuff into these pointers, and then as the
	126	* stack is unwound, the code generated into each function (for
	127	* checking whether this function contains a relevant "catch"
	128	* clause and for calling destructors for local variables) looks
	129	* at these globals to find the type and value thrown.
	130	*
	131	* The problem was that the compiler generated the symbols as
	132	* "common" symbols, and common symbols cannot be placed in
	133	* dynamic shared libraries. So we must put these guys as
	134	* "data" symbols into crt0.o or the System Framework (library),
	135	* and the compiler must generate code that defines the symbols
	136	* as external references instead of common.
	137	*
	138	* I changed the symbol names (added the "_272") to be utterly
	139	* paranoid about any possible future use of similar names by
	140	* any future versions of gcc.
	141	* -- D. Landauer, Jan. 1998
	142	*/
	143
	144	void __eh_pc_gcc_272 = (void )0;
	145	void __eh_type_gcc_272 = (void )0;
	146	void __eh_value_gcc_272 = (void )0;
	147
	148	/* This is what egcs uses for its global data pointer */
	149	void __eh_global_dataptr = (void )0;
34e8f829 A	150	#endif /* __ppc__ */
34e8f829 A	151