1 /* dl_vms.xs 2 * 3 * Platform: OpenVMS, VAX or AXP or IA64 4 * Author: Charles Bailey bailey@newman.upenn.edu 5 * Revised: See http://public.activestate.com/cgi-bin/perlbrowse 6 * 7 * Implementation Note 8 * This section is added as an aid to users and DynaLoader developers, in 9 * order to clarify the process of dynamic linking under VMS. 10 * dl_vms.xs uses the supported VMS dynamic linking call, which allows 11 * a running program to map an arbitrary file of executable code and call 12 * routines within that file. This is done via the VMS RTL routine 13 * lib$find_image_symbol, whose calling sequence is as follows: 14 * status = lib$find_image_symbol(imgname,symname,symval,defspec); 15 * where 16 * status = a standard VMS status value (unsigned long int) 17 * imgname = a fixed-length string descriptor, passed by 18 * reference, containing the NAME ONLY of the image 19 * file to be mapped. An attempt will be made to 20 * translate this string as a logical name, so it may 21 * not contain any characters which are not allowed in 22 * logical names. If no translation is found, imgname 23 * is used directly as the name of the image file. 24 * symname = a fixed-length string descriptor, passed by 25 * reference, containing the name of the routine 26 * to be located. 27 * symval = an unsigned long int, passed by reference, into 28 * which is written the entry point address of the 29 * routine whose name is specified in symname. 30 * defspec = a fixed-length string descriptor, passed by 31 * reference, containing a default file specification 32 * whichis used to fill in any missing parts of the 33 * image file specification after the imgname argument 34 * is processed. 35 * In order to accommodate the handling of the imgname argument, the routine 36 * dl_expandspec() is provided for use by perl code (e.g. dl_findfile) 37 * which wants to see what image file lib$find_image_symbol would use if 38 * it were passed a given file specification. The file specification passed 39 * to dl_expandspec() and dl_load_file() can be partial or complete, and can 40 * use VMS or Unix syntax; these routines perform the necessary conversions. 41 * In general, writers of perl extensions need only conform to the 42 * procedures set out in the DynaLoader documentation, and let the details 43 * be taken care of by the routines here and in DynaLoader.pm. If anyone 44 * comes across any incompatibilities, please let me know. Thanks. 45 * 46 */ 47 48 #include "EXTERN.h" 49 #include "perl.h" 50 #include "XSUB.h" 51 52 #include <descrip.h> 53 #include <fscndef.h> 54 #include <lib$routines.h> 55 #include <rms.h> 56 #include <ssdef.h> 57 #include <starlet.h> 58 59 #if defined(VMS_WE_ARE_CASE_SENSITIVE) 60 #define DL_CASE_SENSITIVE 1<<4 61 #else 62 #define DL_CASE_SENSITIVE 0 63 #endif 64 65 typedef unsigned long int vmssts; 66 67 struct libref { 68 struct dsc$descriptor_s name; 69 struct dsc$descriptor_s defspec; 70 }; 71 72 typedef struct { 73 AV * x_require_symbols; 74 /* "Static" data for dl_expand_filespec() - This is static to save 75 * initialization on each call; if you need context-independence, 76 * just make these auto variables in dl_expandspec() and dl_load_file() 77 */ 78 char x_esa[NAM$C_MAXRSS]; 79 char x_rsa[NAM$C_MAXRSS]; 80 struct FAB x_fab; 81 struct NAM x_nam; 82 } my_cxtx_t; /* this *must* be named my_cxtx_t */ 83 84 #define DL_CXT_EXTRA /* ask for dl_cxtx to be defined in dlutils.c */ 85 #include "dlutils.c" /* dl_debug, dl_last_error; SaveError not used */ 86 87 #define dl_require_symbols (dl_cxtx.x_require_symbols) 88 #define dl_esa (dl_cxtx.x_esa) 89 #define dl_rsa (dl_cxtx.x_rsa) 90 #define dl_fab (dl_cxtx.x_fab) 91 #define dl_nam (dl_cxtx.x_nam) 92 93 /* $PutMsg action routine - records error message in dl_last_error */ 94 static vmssts 95 copy_errmsg(msg,unused) 96 struct dsc$descriptor_s * msg; 97 vmssts unused; 98 { 99 dTHX; 100 dMY_CXT; 101 if (*(msg->dsc$a_pointer) == '%') { /* first line */ 102 sv_setpvn(MY_CXT.x_dl_last_error, msg->dsc$a_pointer, (STRLEN)msg->dsc$w_length); 103 } 104 else { /* continuation line */ 105 sv_catpvn(MY_CXT.x_dl_last_error, msg->dsc$a_pointer, (STRLEN)msg->dsc$w_length); 106 } 107 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "Saved error message: %s\n", dl_last_error)); 108 return 0; 109 } 110 111 /* Use $PutMsg to retrieve error message for failure status code */ 112 static void 113 dl_set_error(sts,stv) 114 vmssts sts; 115 vmssts stv; 116 { 117 vmssts vec[3]; 118 dTHX; 119 120 vec[0] = stv ? 2 : 1; 121 vec[1] = sts; vec[2] = stv; 122 _ckvmssts(sys$putmsg(vec,copy_errmsg,0,0)); 123 } 124 125 /* wrapper for lib$find_image_symbol, so signalled errors can be saved 126 * for dl_error and then returned */ 127 static unsigned long int 128 my_find_image_symbol(struct dsc$descriptor_s *imgname, 129 struct dsc$descriptor_s *symname, 130 void (**entry)(), 131 struct dsc$descriptor_s *defspec) 132 { 133 unsigned long int retsts; 134 VAXC$ESTABLISH(lib$sig_to_ret); 135 retsts = lib$find_image_symbol(imgname,symname,entry,defspec,DL_CASE_SENSITIVE); 136 return retsts; 137 } 138 139 140 static void 141 dl_private_init(pTHX) 142 { 143 dl_generic_private_init(aTHX); 144 { 145 dMY_CXT; 146 dl_require_symbols = get_av("DynaLoader::dl_require_symbols", GV_ADDMULTI); 147 /* Set up the static control blocks for dl_expand_filespec() */ 148 dl_fab = cc$rms_fab; 149 dl_nam = cc$rms_nam; 150 dl_fab.fab$l_nam = &dl_nam; 151 dl_nam.nam$l_esa = dl_esa; 152 dl_nam.nam$b_ess = sizeof dl_esa; 153 dl_nam.nam$l_rsa = dl_rsa; 154 dl_nam.nam$b_rss = sizeof dl_rsa; 155 } 156 } 157 MODULE = DynaLoader PACKAGE = DynaLoader 158 159 BOOT: 160 (void)dl_private_init(aTHX); 161 162 void 163 dl_expandspec(filespec) 164 char * filespec 165 CODE: 166 char vmsspec[NAM$C_MAXRSS], defspec[NAM$C_MAXRSS]; 167 size_t deflen; 168 vmssts sts; 169 dMY_CXT; 170 171 tovmsspec(filespec,vmsspec); 172 dl_fab.fab$l_fna = vmsspec; 173 dl_fab.fab$b_fns = strlen(vmsspec); 174 dl_fab.fab$l_dna = 0; 175 dl_fab.fab$b_dns = 0; 176 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_expand_filespec(%s):\n",vmsspec)); 177 /* On the first pass, just parse the specification string */ 178 dl_nam.nam$b_nop = NAM$M_SYNCHK; 179 sts = sys$parse(&dl_fab); 180 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tSYNCHK sys$parse = %d\n",sts)); 181 if (!(sts & 1)) { 182 dl_set_error(dl_fab.fab$l_sts,dl_fab.fab$l_stv); 183 ST(0) = &PL_sv_undef; 184 } 185 else { 186 /* Now set up a default spec - everything but the name */ 187 deflen = dl_nam.nam$l_name - dl_esa; 188 memcpy(defspec,dl_esa,deflen); 189 memcpy(defspec+deflen,dl_nam.nam$l_type, 190 dl_nam.nam$b_type + dl_nam.nam$b_ver); 191 deflen += dl_nam.nam$b_type + dl_nam.nam$b_ver; 192 memcpy(vmsspec,dl_nam.nam$l_name,dl_nam.nam$b_name); 193 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tsplit filespec: name = %.*s, default = %.*s\n", 194 dl_nam.nam$b_name,vmsspec,deflen,defspec)); 195 /* . . . and go back to expand it */ 196 dl_nam.nam$b_nop = 0; 197 dl_fab.fab$l_dna = defspec; 198 dl_fab.fab$b_dns = deflen; 199 dl_fab.fab$b_fns = dl_nam.nam$b_name; 200 sts = sys$parse(&dl_fab); 201 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tname/default sys$parse = %d\n",sts)); 202 if (!(sts & 1)) { 203 dl_set_error(dl_fab.fab$l_sts,dl_fab.fab$l_stv); 204 ST(0) = &PL_sv_undef; 205 } 206 else { 207 /* Now find the actual file */ 208 sts = sys$search(&dl_fab); 209 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tsys$search = %d\n",sts)); 210 if (!(sts & 1)) { 211 dl_set_error(dl_fab.fab$l_sts,dl_fab.fab$l_stv); 212 ST(0) = &PL_sv_undef; 213 } 214 else { 215 ST(0) = sv_2mortal(newSVpvn(dl_nam.nam$l_rsa,dl_nam.nam$b_rsl)); 216 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "\tresult = \\%.*s\\\n", 217 dl_nam.nam$b_rsl,dl_nam.nam$l_rsa)); 218 } 219 } 220 } 221 222 void 223 dl_load_file(filename, flags=0) 224 char * filename 225 int flags 226 PREINIT: 227 dTHX; 228 dMY_CXT; 229 char vmsspec[NAM$C_MAXRSS]; 230 SV *reqSV, **reqSVhndl; 231 STRLEN deflen; 232 struct dsc$descriptor_s 233 specdsc = {0, DSC$K_DTYPE_T, DSC$K_CLASS_S, 0}, 234 symdsc = {0, DSC$K_DTYPE_T, DSC$K_CLASS_S, 0}; 235 struct fscnlst { 236 unsigned short int len; 237 unsigned short int code; 238 char *string; 239 } namlst[2] = {{0,FSCN$_NAME,0},{0,0,0}}; 240 struct libref *dlptr; 241 vmssts sts, failed = 0; 242 void (*entry)(); 243 CODE: 244 245 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_load_file(%s,%x):\n", filename,flags)); 246 specdsc.dsc$a_pointer = tovmsspec(filename,vmsspec); 247 specdsc.dsc$w_length = strlen(specdsc.dsc$a_pointer); 248 if (specdsc.dsc$w_length == 0) { /* undef in, empty out */ 249 XSRETURN_EMPTY; 250 } 251 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tVMS-ified filename is %s\n", 252 specdsc.dsc$a_pointer)); 253 Newx(dlptr,1,struct libref); 254 dlptr->name.dsc$b_dtype = dlptr->defspec.dsc$b_dtype = DSC$K_DTYPE_T; 255 dlptr->name.dsc$b_class = dlptr->defspec.dsc$b_class = DSC$K_CLASS_S; 256 sts = sys$filescan(&specdsc,namlst,0); 257 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tsys$filescan: returns %d, name is %.*s\n", 258 sts,namlst[0].len,namlst[0].string)); 259 if (!(sts & 1)) { 260 failed = 1; 261 dl_set_error(sts,0); 262 } 263 else { 264 dlptr->name.dsc$w_length = namlst[0].len; 265 dlptr->name.dsc$a_pointer = savepvn(namlst[0].string,namlst[0].len); 266 dlptr->defspec.dsc$w_length = specdsc.dsc$w_length - namlst[0].len; 267 Newx(dlptr->defspec.dsc$a_pointer, dlptr->defspec.dsc$w_length + 1, char); 268 deflen = namlst[0].string - specdsc.dsc$a_pointer; 269 memcpy(dlptr->defspec.dsc$a_pointer,specdsc.dsc$a_pointer,deflen); 270 memcpy(dlptr->defspec.dsc$a_pointer + deflen, 271 namlst[0].string + namlst[0].len, 272 dlptr->defspec.dsc$w_length - deflen); 273 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tlibref = name: %s, defspec: %.*s\n", 274 dlptr->name.dsc$a_pointer, 275 dlptr->defspec.dsc$w_length, 276 dlptr->defspec.dsc$a_pointer)); 277 if (!(reqSVhndl = av_fetch(dl_require_symbols,0,FALSE)) || !(reqSV = *reqSVhndl)) { 278 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\t@dl_require_symbols empty, returning untested libref\n")); 279 } 280 else { 281 symdsc.dsc$w_length = SvCUR(reqSV); 282 symdsc.dsc$a_pointer = SvPVX(reqSV); 283 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\t$dl_require_symbols[0] = %.*s\n", 284 symdsc.dsc$w_length, symdsc.dsc$a_pointer)); 285 sts = my_find_image_symbol(&(dlptr->name),&symdsc, 286 &entry,&(dlptr->defspec)); 287 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tlib$find_image_symbol returns %d\n",sts)); 288 if (!(sts&1)) { 289 failed = 1; 290 dl_set_error(sts,0); 291 } 292 } 293 } 294 295 if (failed) { 296 Safefree(dlptr->name.dsc$a_pointer); 297 Safefree(dlptr->defspec.dsc$a_pointer); 298 Safefree(dlptr); 299 ST(0) = &PL_sv_undef; 300 } 301 else { 302 ST(0) = sv_2mortal(newSViv(PTR2IV(dlptr))); 303 } 304 305 306 void 307 dl_find_symbol(librefptr,symname) 308 void * librefptr 309 SV * symname 310 CODE: 311 struct libref thislib = *((struct libref *)librefptr); 312 struct dsc$descriptor_s 313 symdsc = {SvCUR(symname),DSC$K_DTYPE_T,DSC$K_CLASS_S,SvPVX(symname)}; 314 void (*entry)(); 315 vmssts sts; 316 317 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_find_symbol(%.*s,%.*s):\n", 318 thislib.name.dsc$w_length, thislib.name.dsc$a_pointer, 319 symdsc.dsc$w_length,symdsc.dsc$a_pointer)); 320 sts = my_find_image_symbol(&(thislib.name),&symdsc, 321 &entry,&(thislib.defspec)); 322 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tlib$find_image_symbol returns %d\n",sts)); 323 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tentry point is %d\n", 324 (unsigned long int) entry)); 325 if (!(sts & 1)) { 326 dl_set_error(sts,0); 327 ST(0) = &PL_sv_undef; 328 } 329 else ST(0) = sv_2mortal(newSViv(PTR2IV(entry))); 330 331 332 void 333 dl_undef_symbols() 334 PPCODE: 335 336 337 # These functions should not need changing on any platform: 338 339 void 340 dl_install_xsub(perl_name, symref, filename="$Package") 341 char * perl_name 342 void * symref 343 const char * filename 344 CODE: 345 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "dl_install_xsub(name=%s, symref=%x)\n", 346 perl_name, symref)); 347 ST(0) = sv_2mortal(newRV((SV*)newXS_flags(perl_name, 348 (void(*)(pTHX_ CV *))symref, 349 filename, NULL, 350 XS_DYNAMIC_FILENAME))); 351 352 353 char * 354 dl_error() 355 CODE: 356 dMY_CXT; 357 RETVAL = dl_last_error ; 358 OUTPUT: 359 RETVAL 360 361 #if defined(USE_ITHREADS) 362 363 void 364 CLONE(...) 365 CODE: 366 MY_CXT_CLONE; 367 368 /* MY_CXT_CLONE just does a memcpy on the whole structure, so to avoid 369 * using Perl variables that belong to another thread, we create our 370 * own for this thread. 371 */ 372 MY_CXT.x_dl_last_error = newSVpvn("", 0); 373 dl_require_symbols = get_av("DynaLoader::dl_require_symbols", GV_ADDMULTI); 374 375 #endif 376 377 # end. 378