cctools/libmacho/get_end.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   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
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  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.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #ifndef RLD
  24 #include <string.h>
  25 #include <mach-o/ldsyms.h>
  26 #include <mach-o/getsect.h>
  27 #ifndef __OPENSTEP__
  28 #include <crt_externs.h>
  29 #else /* defined(__OPENSTEP__) */
  30 #ifdef __DYNAMIC__
  31 #include "mach-o/dyld.h" /* defines _dyld_lookup_and_bind() */
  32 #endif
  33
  34 #if !defined(__DYNAMIC__)
  35 #define DECLARE_VAR(var, type) \
  36 extern type var
  37 #define SETUP_VAR(var)
  38 #define USE_VAR(var) var
  39 #else
  40 #define STRINGIFY(a) # a
  41 #define DECLARE_VAR(var, type)  \
  42 static type * var ## _pointer = 0
  43 #define SETUP_VAR(var)                                          \
  44 if ( var ## _pointer == 0) {                            \
  45     _dyld_lookup_and_bind( STRINGIFY(_ ## var),         \
  46                            (uint32_t *) & var ## _pointer, 0);  \
  47 }
  48 #define USE_VAR(var) (* var ## _pointer)
  49 #endif
  50 #endif /* __OPENSTEP__ */
  51
  52 /*
  53  * This routine returns the highest address of the segments in the program (NOT
  54  * the shared libraries).  It is intended to be used as a stop gap for programs
  55  * that make UNIX style assumptions about how memory is allocated.  Typicly the
  56  * asumptions under which this is used is that memory is contiguously allocated
  57  * by the program's text and data from address 0 with no gaps.  The value of
  58  * this differs from the value of &_end in a UNIX program in that this routine
  59  * returns the address of the end of the segment not the end of the last section
  60  * in that segment as would be the value of the symbol &_end.
  61  */
  62 unsigned long
  63 get_end(void)
  64 {
  65 #ifndef __LP64__
  66
  67     struct segment_command *sgp;
  68     unsigned long _end;
  69     uint32_t i;
  70 #ifndef __OPENSTEP__
  71     struct mach_header *mhp = _NSGetMachExecuteHeader();
  72 #else /* defined(__OPENSTEP__) */
  73     static struct mach_header *mhp = NULL;
  74         DECLARE_VAR(_mh_execute_header, struct mach_header);
  75         SETUP_VAR(_mh_execute_header);
  76
  77         mhp = (struct mach_header *)(& USE_VAR(_mh_execute_header));
  78 #endif /* __OPENSTEP__ */
  79         _end = 0;
  80         sgp = (struct segment_command *)
  81               ((char *)mhp + sizeof(struct mach_header));
  82         for(i = 0; i < mhp->ncmds; i++){
  83             if(sgp->cmd == LC_SEGMENT)
  84                 if(sgp->vmaddr + sgp->vmsize > _end)
  85                     _end = sgp->vmaddr + sgp->vmsize;
  86             sgp = (struct segment_command *)((char *)sgp + sgp->cmdsize);
  87         }
  88         return(_end);
  89
  90 #else /* defined(__LP64__) */
  91
  92     struct mach_header_64 *mhp = _NSGetMachExecuteHeader();
  93     struct segment_command_64 *sgp;
  94     unsigned long _end;
  95     uint32_t i;
  96
  97         _end = 0;
  98         sgp = (struct segment_command_64 *)
  99               ((char *)mhp + sizeof(struct mach_header_64));
 100         for(i = 0; i < mhp->ncmds; i++){
 101             if(sgp->cmd == LC_SEGMENT_64)
 102                 if(sgp->vmaddr + sgp->vmsize > _end)
 103                     _end = sgp->vmaddr + sgp->vmsize;
 104             sgp = (struct segment_command_64 *)((char *)sgp + sgp->cmdsize);
 105         }
 106         return(_end);
 107
 108 #endif /* defined(__LP64__) */
 109 }
 110
 111 /*
 112  * This returns what was the value of the UNIX link editor defined symbol
 113  * _etext (the first address after the text section).  Note this my or may not
 114  * be the only section in the __TEXT segment.
 115  */
 116 unsigned long
 117 get_etext(void)
 118 {
 119 #ifndef __LP64__
 120     const struct section *sp;
 121 #else /* defined(__LP64__) */
 122     const struct section_64 *sp;
 123 #endif /* defined(__LP64__) */
 124
 125         sp = getsectbyname(SEG_TEXT, SECT_TEXT);
 126         if(sp)
 127             return(sp->addr + sp->size);
 128         else
 129             return(0);
 130 }
 131
 132 /*
 133  * This returns what was the value of the UNIX link editor defined symbol
 134  * _edata (the first address after the data section).  Note this my or may not
 135  * be the last non-zero fill section in the __DATA segment.
 136  */
 137 unsigned long
 138 get_edata(void)
 139 {
 140 #ifndef __LP64__
 141     const struct section *sp;
 142 #else /* defined(__LP64__) */
 143     const struct section_64 *sp;
 144 #endif /* defined(__LP64__) */
 145
 146         sp = getsectbyname(SEG_DATA, SECT_DATA);
 147         if(sp)
 148             return(sp->addr + sp->size);
 149         else
 150             return(0);
 151 }
 152 #endif /* !defined(RLD) */