1 /* loader-shl_load.c -- dynamic linking with shl_load (HP-UX) 2 3 Copyright (C) 1998-2000, 2004, 2006-2008, 2011-2015 Free Software 4 Foundation, Inc. 5 Written by Thomas Tanner, 1998 6 7 NOTE: The canonical source of this file is maintained with the 8 GNU Libtool package. Report bugs to bug-libtool@gnu.org. 9 10 GNU Libltdl is free software; you can redistribute it and/or 11 modify it under the terms of the GNU Lesser General Public 12 License as published by the Free Software Foundation; either 13 version 2 of the License, or (at your option) any later version. 14 15 As a special exception to the GNU Lesser General Public License, 16 if you distribute this file as part of a program or library that 17 is built using GNU Libtool, you may include this file under the 18 same distribution terms that you use for the rest of that program. 19 20 GNU Libltdl is distributed in the hope that it will be useful, 21 but WITHOUT ANY WARRANTY; without even the implied warranty of 22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 23 GNU Lesser General Public License for more details. 24 25 You should have received a copy of the GNU Lesser General Public 26 License along with GNU Libltdl; see the file COPYING.LIB. If not, a 27 copy can be downloaded from http://www.gnu.org/licenses/lgpl.html, 28 or obtained by writing to the Free Software Foundation, Inc., 29 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 30 */ 31 32 #include "lt__private.h" 33 #include "lt_dlloader.h" 34 35 /* Use the preprocessor to rename non-static symbols to avoid namespace 36 collisions when the loader code is statically linked into libltdl. 37 Use the "<module_name>_LTX_" prefix so that the symbol addresses can 38 be fetched from the preloaded symbol list by lt_dlsym(): */ 39 #define get_vtable shl_load_LTX_get_vtable 40 41 LT_BEGIN_C_DECLS 42 LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data); 43 LT_END_C_DECLS 44 45 46 /* Boilerplate code to set up the vtable for hooking this loader into 47 libltdl's loader list: */ 48 static int vl_exit (lt_user_data loader_data); 49 static lt_module vm_open (lt_user_data loader_data, const char *filename, 50 lt_dladvise advise); 51 static int vm_close (lt_user_data loader_data, lt_module module); 52 static void * vm_sym (lt_user_data loader_data, lt_module module, 53 const char *symbolname); 54 55 static lt_dlvtable *vtable = 0; 56 57 /* Return the vtable for this loader, only the name and sym_prefix 58 attributes (plus the virtual function implementations, obviously) 59 change between loaders. */ 60 lt_dlvtable * 61 get_vtable (lt_user_data loader_data) /* */ 62 { 63 if (!vtable) 64 { 65 vtable = lt__zalloc (sizeof *vtable); 66 } 67 68 if (vtable && !vtable->name) 69 { 70 vtable->name = "lt_shl_load"; 71 vtable->module_open = vm_open; 72 vtable->module_close = vm_close; 73 vtable->find_sym = vm_sym; 74 vtable->dlloader_exit = vl_exit; 75 vtable->dlloader_data = loader_data; 76 vtable->priority = LT_DLLOADER_APPEND; 77 } 78 79 if (vtable && (vtable->dlloader_data != loader_data)) 80 { 81 LT__SETERROR (INIT_LOADER); 82 return 0; 83 } 84 85 return vtable; 86 } 87 88 89 90 /* --- IMPLEMENTATION --- */ 91 92 93 #if defined HAVE_DL_H 94 # include <dl.h> 95 #endif 96 97 /* some flags are missing on some systems, so we provide 98 * harmless defaults. 99 * 100 * Mandatory: 101 * BIND_IMMEDIATE - Resolve symbol references when the library is loaded. 102 * BIND_DEFERRED - Delay code symbol resolution until actual reference. 103 * 104 * Optionally: 105 * BIND_FIRST - Place the library at the head of the symbol search 106 * order. 107 * BIND_NONFATAL - The default BIND_IMMEDIATE behavior is to treat all 108 * unsatisfied symbols as fatal. This flag allows 109 * binding of unsatisfied code symbols to be deferred 110 * until use. 111 * [Perl: For certain libraries, like DCE, deferred 112 * binding often causes run time problems. Adding 113 * BIND_NONFATAL to BIND_IMMEDIATE still allows 114 * unresolved references in situations like this.] 115 * BIND_NOSTART - Do not call the initializer for the shared library 116 * when the library is loaded, nor on a future call to 117 * shl_unload(). 118 * BIND_VERBOSE - Print verbose messages concerning possible 119 * unsatisfied symbols. 120 * 121 * hp9000s700/hp9000s800: 122 * BIND_RESTRICTED - Restrict symbols visible by the library to those 123 * present at library load time. 124 * DYNAMIC_PATH - Allow the loader to dynamically search for the 125 * library specified by the path argument. 126 */ 127 128 #if !defined DYNAMIC_PATH 129 # define DYNAMIC_PATH 0 130 #endif 131 #if !defined BIND_RESTRICTED 132 # define BIND_RESTRICTED 0 133 #endif 134 135 #define LT_BIND_FLAGS (BIND_IMMEDIATE | BIND_NONFATAL | DYNAMIC_PATH) 136 137 138 /* A function called through the vtable when this loader is no 139 longer needed by the application. */ 140 static int 141 vl_exit (lt_user_data loader_data LT__UNUSED) /* */ 142 { 143 vtable = NULL; 144 return 0; 145 } 146 147 /* A function called through the vtable to open a module with this 148 loader. Returns an opaque representation of the newly opened 149 module for processing with this loader's other vtable functions. */ 150 static lt_module 151 vm_open (lt_user_data loader_data LT__UNUSED, const char *filename, /* */ 152 lt_dladvise advise LT__UNUSED) 153 { 154 static shl_t self = (shl_t) 0; 155 lt_module module = shl_load (filename, LT_BIND_FLAGS, 0L); 156 157 /* Since searching for a symbol against a NULL module handle will also 158 look in everything else that was already loaded and exported with 159 the -E compiler flag, we always cache a handle saved before any 160 modules are loaded. */ 161 if (!self) 162 { 163 void *address; 164 shl_findsym (&self, "main", TYPE_UNDEFINED, &address); 165 } 166 167 if (!filename) 168 { 169 module = self; 170 } 171 else 172 { 173 module = shl_load (filename, LT_BIND_FLAGS, 0L); 174 175 if (!module) 176 { 177 LT__SETERROR (CANNOT_OPEN); 178 } 179 } 180 181 return module; 182 } 183 184 /* A function called through the vtable when a particular module 185 should be unloaded. */ 186 static int 187 vm_close (lt_user_data loader_data LT__UNUSED, lt_module module) /* */ 188 { 189 int errors = 0; 190 191 if (module && (shl_unload ((shl_t) (module)) != 0)) 192 { 193 LT__SETERROR (CANNOT_CLOSE); 194 ++errors; 195 } 196 197 return errors; 198 } 199 200 201 /* A function called through the vtable to get the address of 202 a symbol loaded from a particular module. */ 203 static void * 204 vm_sym (lt_user_data loader_data LT__UNUSED, lt_module module, const char *name) /* */ 205 { 206 void *address = 0; 207 208 /* sys_shl_open should never return a NULL module handle */ 209 if (module == (lt_module) 0) 210 { 211 LT__SETERROR (INVALID_HANDLE); 212 } 213 else if (!shl_findsym((shl_t*) &module, name, TYPE_UNDEFINED, &address)) 214 { 215 if (!address) 216 { 217 LT__SETERROR (SYMBOL_NOT_FOUND); 218 } 219 } 220 221 return address; 222 }