1 /* $OpenBSD: crtbegin.c,v 1.12 2007/09/03 14:40:16 millert Exp $ */ 2 /* $NetBSD: crtbegin.c,v 1.1 1996/09/12 16:59:03 cgd Exp $ */ 3 4 /* 5 * Copyright (c) 1993 Paul Kranenburg 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by Paul Kranenburg. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 /* 35 * Run-time module for GNU C++ compiled shared libraries. 36 * 37 * The linker constructs the following arrays of pointers to global 38 * constructors and destructors. The first element contains the 39 * number of pointers in each. 40 * The tables are also null-terminated. 41 */ 42 #include <stdlib.h> 43 44 #include "md_init.h" 45 #include "os-note-elf.h" 46 #include "extern.h" 47 48 struct dwarf2_eh_object { 49 void *space[8]; 50 }; 51 52 void __register_frame_info(const void *, struct dwarf2_eh_object *) 53 __attribute__((weak)); 54 55 void __register_frame_info(const void *begin, struct dwarf2_eh_object *ob) 56 { 57 } 58 59 static const char __EH_FRAME_BEGIN__[] 60 __attribute__((section(".eh_frame"), aligned(4))) = { }; 61 62 /* 63 * Include support for the __cxa_atexit/__cxa_finalize C++ abi for 64 * gcc > 2.x. __dso_handle is NULL in the main program and a unique 65 * value for each C++ shared library. For more info on this API, see: 66 * 67 * http://www.codesourcery.com/cxx-abi/abi.html#dso-dtor 68 */ 69 70 #if (__GNUC__ > 2) 71 void *__dso_handle = NULL; 72 __asm(".hidden __dso_handle"); 73 #endif 74 75 static const init_f __CTOR_LIST__[1] 76 __attribute__((section(".ctors"))) = { (void *)-1 }; /* XXX */ 77 static const init_f __DTOR_LIST__[1] 78 __attribute__((section(".dtors"))) = { (void *)-1 }; /* XXX */ 79 80 static void __dtors(void); 81 static void __ctors(void); 82 83 static void 84 __dtors() 85 { 86 unsigned long i = (unsigned long) __DTOR_LIST__[0]; 87 const init_f *p; 88 89 if (i == -1) { 90 for (i = 1; __DTOR_LIST__[i] != NULL; i++) 91 ; 92 i--; 93 } 94 p = __DTOR_LIST__ + i; 95 while (i--) 96 (**p--)(); 97 } 98 99 static void 100 __ctors() 101 { 102 const init_f *p = __CTOR_LIST__ + 1; 103 104 while (*p) 105 (**p++)(); 106 } 107 108 void __init(void); 109 void __fini(void); 110 static void __do_init(void); 111 static void __do_fini(void); 112 113 MD_SECTION_PROLOGUE(".init", __init); 114 115 MD_SECTION_PROLOGUE(".fini", __fini); 116 117 MD_SECT_CALL_FUNC(".init", __do_init); 118 MD_SECT_CALL_FUNC(".fini", __do_fini); 119 120 121 void 122 __do_init() 123 { 124 static int initialized = 0; 125 static struct dwarf2_eh_object object; 126 127 /* 128 * Call global constructors. 129 * Arrange to call global destructors at exit. 130 */ 131 if (!initialized) { 132 initialized = 1; 133 134 __register_frame_info(__EH_FRAME_BEGIN__, &object); 135 136 (__ctors)(); 137 138 atexit(__fini); 139 } 140 } 141 142 void 143 __do_fini() 144 { 145 static int finalized = 0; 146 147 if (!finalized) { 148 finalized = 1; 149 /* 150 * Call global destructors. 151 */ 152 (__dtors)(); 153 } 154 } 155 156