Libc-262.tar.gz

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

/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This 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 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 SETUP_VAR(var)						\
    if ( var ## _pointer == 0) {				\
        _dyld_lookup_and_bind( STRINGIFY(_ ## var),		\
                (unsigned long *) & var ## _pointer, 0);	\
    }
#define USE_VAR(var) (var ## _pointer)
#else
#define DECLARE_VAR(var, type) extern type var
#define 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_VAR(__progname, char *);
    SETUP_VAR(__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;

void *__keymgr_global[3] = { (void *)0 };