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Annotation of objc/cplus_init.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
                      3:  *
                      4:  * @APPLE_LICENSE_HEADER_START@
                      5:  * 
                      6:  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
                      7:  * Reserved.  This file contains Original Code and/or Modifications of
                      8:  * Original Code as defined in and that are subject to the Apple Public
                      9:  * Source License Version 1.0 (the 'License').  You may not use this file
                     10:  * except in compliance with the License.  Please obtain a copy of the
                     11:  * License at http://www.apple.com/publicsource and read it before using
                     12:  * this file.
                     13:  * 
                     14:  * The Original Code and all software distributed under the License are
                     15:  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
                     16:  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
                     17:  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
                     18:  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
                     19:  * License for the specific language governing rights and limitations
                     20:  * under the License."
                     21:  * 
                     22:  * @APPLE_LICENSE_HEADER_END@
                     23:  */
                     24: 
                     25: #ifndef KERNEL
                     26: #ifdef SHLIB
                     27: #include "shlib.h"
                     28: #endif
                     29: 
                     30: #include <libc.h>
                     31: #include <stdlib.h>
                     32: #include <mach-o/loader.h>
                     33: 
                     34: static void call_constructors (void);
                     35: static void call_destructors (void);
                     36: static void call_routines_for_section (const struct mach_header **headers,
                     37:                                       const char *segment_name,
                     38:                                       const char *section_name);
                     39: 
                     40: /* Perform C++ initialization.  This only works for the MH_EXECUTE and
                     41:    MH_FVMLIB formats, since the headers must be mapped.
                     42:    
                     43:    crt0.o uses the trick of declaring a common symbol with the same name
                     44:    as this function to call this routine if it is linked in for some other
                     45:    reason, but without forcing it to be linked in itself. */
                     46: 
                     47: void _cplus_init (void)
                     48: {
                     49:   /* Each module which contains constructors or destructors should
                     50:      contain an undefined reference to these symbols to ensure that
                     51:      this initialization routine is linked in. */
                     52:   asm (".globl .constructors_used");
                     53:   asm (".constructors_used = 0");
                     54:   asm (".globl .destructors_used");
                     55:   asm (".destructors_used = 0");
                     56:   
                     57:   atexit (&call_destructors);
                     58:   call_constructors ();
                     59: }
                     60: 
                     61: 
                     62: /* Call the appropriate contructor for each static object in the program. */
                     63: 
                     64: static void call_constructors (void)
                     65: {
                     66:   const struct mach_header **headers = getmachheaders ();
                     67: 
                     68:   call_routines_for_section (headers, "__TEXT", "__constructor");
                     69:   free (headers);
                     70: }
                     71: 
                     72: 
                     73: /* Call the appropriate destructor for each static object in the program. */
                     74: 
                     75: static void call_destructors (void)
                     76: {
                     77:   const struct mach_header **headers = getmachheaders ();
                     78: 
                     79:   call_routines_for_section (getmachheaders (), "__TEXT", "__destructor");
                     80:   free (headers);
                     81: }
                     82: 
                     83: 
                     84: /* Call the init functions in the specified section of each header.
                     85:    The section is assumed to contain a sequential list of function pointers.
                     86:    The functions are called with no arguments, and no return value is
                     87:    expected. */
                     88: 
                     89: static void call_routines_for_section (const struct mach_header **headers,
                     90:                                       const char *segment_name,
                     91:                                       const char *section_name)
                     92: {
                     93:   unsigned int i;
                     94:   
                     95:   if (headers == NULL)
                     96:     return;
                     97:   
                     98:   for (i = 0; headers[i] != NULL; i++)
                     99:     {
                    100:       const struct section *section;
                    101:       void (**init_routines) (void);
                    102:       unsigned int n, j;
                    103:       
                    104:       section = getsectbynamefromheader (headers[i],
                    105:                                         segment_name,
                    106:                                         section_name);
                    107:       
                    108:       if (section == NULL)
                    109:         continue;
                    110:       
                    111:       init_routines = (void (**) (void)) section->addr;
                    112:       n = section->size / sizeof (init_routines[0]);
                    113:       
                    114:       for (j = 0; j < n; j++)
                    115:        (*init_routines[j]) ();
                    116:     }
                    117: }
                    118: 
                    119: #endif /* KERNEL */

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