crt_externs.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23 ** This file contains interfaces to the symbols defined int the crt modules.
  24 ** 3 April 1995
  25 ** Matt Watson (mwatson@next.com)
  26 **
  27 */
  28
  29 #if defined(__DYNAMIC__)
  30 #include "mach-o/dyld.h" /* defines _dyld_lookup_and_bind() */
  31 #define STRINGIFY(a) # a
  32 #define DECLARE_VAR(var, type)  \
  33         static type * var ## _pointer = 0
  34 #define SETUP_VAR(var)                                          \
  35     if ( var ## _pointer == 0) {                                \
  36         _dyld_lookup_and_bind( STRINGIFY(_ ## var),             \
  37                 (unsigned long *) & var ## _pointer, 0);        \
  38     }
  39 #define USE_VAR(var) (var ## _pointer)
  40 #else
  41 #define DECLARE_VAR(var, type) extern type var
  42 #define SETUP_VAR(var)
  43 #define USE_VAR(var) (& var)
  44 #endif
  45
  46 char ***_NSGetArgv(void) {
  47     DECLARE_VAR(NXArgv, char **);
  48     SETUP_VAR(NXArgv);
  49     return(USE_VAR(NXArgv));
  50 }
  51
  52 int *_NSGetArgc(void) {
  53     DECLARE_VAR(NXArgc, int);
  54     SETUP_VAR(NXArgc);
  55     return(USE_VAR(NXArgc));
  56 }
  57
  58 char ***_NSGetEnviron(void) {
  59     DECLARE_VAR(environ, char **);
  60     SETUP_VAR(environ);
  61     return(USE_VAR(environ));
  62 }
  63
  64 struct mach_header *_NSGetMachExecuteHeader(void) {
  65     DECLARE_VAR(_mh_execute_header, struct mach_header);
  66     SETUP_VAR(_mh_execute_header);
  67     return(USE_VAR(_mh_execute_header));
  68 }
  69
  70 /*
  71  * Fix for Radar bug 2200596 --
  72  * EH symbol definitions for gcc 2.7.2.x implementation of
  73  * C++ exception handling.  The problem:  the EH implementation
  74  * has "throw" store stuff into these pointers, and then as the
  75  * stack is unwound, the code generated into each function (for
  76  * checking whether this function contains a relevant "catch"
  77  * clause and for calling destructors for local variables) looks
  78  * at these globals to find the type and value thrown.
  79  *
  80  * The problem was that the compiler generated the symbols as
  81  * "common" symbols, and common symbols cannot be placed in
  82  * dynamic shared libraries.  So we must put these guys as
  83  * "data" symbols into crt0.o or the System Framework (library),
  84  * and the compiler must generate code that defines the symbols
  85  * as external references instead of common.
  86  *
  87  * I changed the symbol names (added the "_272") to be utterly
  88  * paranoid about any possible future use of similar names by
  89  * any future versions of gcc.
  90  *                      -- D. Landauer, Jan. 1998
  91  */
  92
  93 void *__eh_pc_gcc_272 = (void *)0;
  94 void *__eh_type_gcc_272 = (void *)0;
  95 void *__eh_value_gcc_272 = (void *)0;
  96
  97 /* This is what egcs uses for its global data pointer */
  98 void *__eh_global_dataptr = (void *)0;
  99
 100 void *__keymgr_global[3] = { (void *)0 };