3 * Platform: OpenVMS, VAX or AXP
4 * Author: Charles Bailey bailey@newman.upenn.edu
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);
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
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
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$find_image_symbol would use if
38 * it were passed a given file specification. The file specification passed
39 * to dl_expandspec() and dl_load_file() can be partial or complete, and can
40 * use VMS or Unix syntax; these routines perform the necessary conversions.
41 * In general, writers of perl extensions need only conform to the
42 * procedures set out in the DynaLoader documentation, and let the details
43 * be taken care of by the routines here and in DynaLoader.pm. If anyone
44 * comes across any incompatibilities, please let me know. Thanks.
53 * dl_debug and dl_last_error are static vars; you'll need to deal
54 * with them appropriately if you need context independence
59 #include <lib$routines.h>
64 #if defined(VMS_WE_ARE_CASE_SENSITIVE)
65 #define DL_CASE_SENSITIVE 1<<4
67 #define DL_CASE_SENSITIVE 0
70 typedef unsigned long int vmssts;
73 struct dsc$descriptor_s name;
74 struct dsc$descriptor_s defspec;
78 AV * x_require_symbols;
79 /* "Static" data for dl_expand_filespec() - This is static to save
80 * initialization on each call; if you need context-independence,
81 * just make these auto variables in dl_expandspec() and dl_load_file()
83 char x_esa[NAM$C_MAXRSS];
84 char x_rsa[NAM$C_MAXRSS];
87 } my_cxtx_t; /* this *must* be named my_cxtx_t */
89 #define DL_CXT_EXTRA /* ask for dl_cxtx to be defined in dlutils.c */
90 #include "dlutils.c" /* dl_debug, dl_last_error; SaveError not used */
92 #define dl_require_symbols (dl_cxtx.x_require_symbols)
93 #define dl_esa (dl_cxtx.x_esa)
94 #define dl_rsa (dl_cxtx.x_rsa)
95 #define dl_fab (dl_cxtx.x_fab)
96 #define dl_nam (dl_cxtx.x_nam)
98 /* $PutMsg action routine - records error message in dl_last_error */
100 copy_errmsg(msg,unused)
101 struct dsc$descriptor_s * msg;
105 if (*(msg->dsc$a_pointer) == '%') { /* first line */
107 strncpy((dl_last_error = saferealloc(dl_last_error,msg->dsc$w_length+1)),
108 msg->dsc$a_pointer, msg->dsc$w_length);
110 strncpy((dl_last_error = safemalloc(msg->dsc$w_length+1)),
111 msg->dsc$a_pointer, msg->dsc$w_length);
112 dl_last_error[msg->dsc$w_length] = '\0';
114 else { /* continuation line */
115 int errlen = strlen(dl_last_error);
116 dl_last_error = saferealloc(dl_last_error, errlen + msg->dsc$w_length + 2);
117 dl_last_error[errlen] = '\n'; dl_last_error[errlen+1] = '\0';
118 strncat(dl_last_error, msg->dsc$a_pointer, msg->dsc$w_length);
119 dl_last_error[errlen+msg->dsc$w_length+1] = '\0';
124 /* Use $PutMsg to retrieve error message for failure status code */
126 dl_set_error(sts,stv)
133 vec[0] = stv ? 2 : 1;
134 vec[1] = sts; vec[2] = stv;
135 _ckvmssts(sys$putmsg(vec,copy_errmsg,0,0));
139 findsym_handler(void *sig, void *mech)
142 unsigned long int myvec[8],args, *usig = (unsigned long int *) sig;
143 /* Be paranoid and assume signal vector passed in might be readonly */
144 myvec[0] = args = usig[0] > 10 ? 9 : usig[0] - 1;
145 while (--args) myvec[args] = usig[args];
146 _ckvmssts(sys$putmsg(myvec,copy_errmsg,0,0));
147 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "findsym_handler: received\n\t%s\n",dl_last_error));
151 /* wrapper for lib$find_image_symbol, so signalled errors can be saved
152 * for dl_error and then returned */
153 static unsigned long int
154 my_find_image_symbol(struct dsc$descriptor_s *imgname,
155 struct dsc$descriptor_s *symname,
157 struct dsc$descriptor_s *defspec)
159 unsigned long int retsts;
160 VAXC$ESTABLISH(findsym_handler);
161 retsts = lib$find_image_symbol(imgname,symname,entry,defspec,DL_CASE_SENSITIVE);
167 dl_private_init(pTHX)
169 dl_generic_private_init(aTHX);
172 dl_require_symbols = get_av("DynaLoader::dl_require_symbols", 0x4);
173 /* Set up the static control blocks for dl_expand_filespec() */
176 dl_fab.fab$l_nam = &dl_nam;
177 dl_nam.nam$l_esa = dl_esa;
178 dl_nam.nam$b_ess = sizeof dl_esa;
179 dl_nam.nam$l_rsa = dl_rsa;
180 dl_nam.nam$b_rss = sizeof dl_rsa;
183 MODULE = DynaLoader PACKAGE = DynaLoader
186 (void)dl_private_init(aTHX);
189 dl_expandspec(filespec)
192 char vmsspec[NAM$C_MAXRSS], defspec[NAM$C_MAXRSS];
197 tovmsspec(filespec,vmsspec);
198 dl_fab.fab$l_fna = vmsspec;
199 dl_fab.fab$b_fns = strlen(vmsspec);
200 dl_fab.fab$l_dna = 0;
201 dl_fab.fab$b_dns = 0;
202 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_expand_filespec(%s):\n",vmsspec));
203 /* On the first pass, just parse the specification string */
204 dl_nam.nam$b_nop = NAM$M_SYNCHK;
205 sts = sys$parse(&dl_fab);
206 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tSYNCHK sys$parse = %d\n",sts));
208 dl_set_error(dl_fab.fab$l_sts,dl_fab.fab$l_stv);
209 ST(0) = &PL_sv_undef;
212 /* Now set up a default spec - everything but the name */
213 deflen = dl_nam.nam$l_name - dl_esa;
214 memcpy(defspec,dl_esa,deflen);
215 memcpy(defspec+deflen,dl_nam.nam$l_type,
216 dl_nam.nam$b_type + dl_nam.nam$b_ver);
217 deflen += dl_nam.nam$b_type + dl_nam.nam$b_ver;
218 memcpy(vmsspec,dl_nam.nam$l_name,dl_nam.nam$b_name);
219 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tsplit filespec: name = %.*s, default = %.*s\n",
220 dl_nam.nam$b_name,vmsspec,deflen,defspec));
221 /* . . . and go back to expand it */
222 dl_nam.nam$b_nop = 0;
223 dl_fab.fab$l_dna = defspec;
224 dl_fab.fab$b_dns = deflen;
225 dl_fab.fab$b_fns = dl_nam.nam$b_name;
226 sts = sys$parse(&dl_fab);
227 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tname/default sys$parse = %d\n",sts));
229 dl_set_error(dl_fab.fab$l_sts,dl_fab.fab$l_stv);
230 ST(0) = &PL_sv_undef;
233 /* Now find the actual file */
234 sts = sys$search(&dl_fab);
235 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tsys$search = %d\n",sts));
237 dl_set_error(dl_fab.fab$l_sts,dl_fab.fab$l_stv);
238 ST(0) = &PL_sv_undef;
241 ST(0) = sv_2mortal(newSVpvn(dl_nam.nam$l_rsa,dl_nam.nam$b_rsl));
242 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "\tresult = \\%.*s\\\n",
243 dl_nam.nam$b_rsl,dl_nam.nam$l_rsa));
249 dl_load_file(filespec, flags)
254 char vmsspec[NAM$C_MAXRSS];
255 SV *reqSV, **reqSVhndl;
257 struct dsc$descriptor_s
258 specdsc = {0, DSC$K_DTYPE_T, DSC$K_CLASS_S, 0},
259 symdsc = {0, DSC$K_DTYPE_T, DSC$K_CLASS_S, 0};
261 unsigned short int len;
262 unsigned short int code;
264 } namlst[2] = {{0,FSCN$_NAME,0},{0,0,0}};
265 struct libref *dlptr;
266 vmssts sts, failed = 0;
271 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_load_file(%s,%x):\n", filespec,flags));
272 specdsc.dsc$a_pointer = tovmsspec(filespec,vmsspec);
273 specdsc.dsc$w_length = strlen(specdsc.dsc$a_pointer);
274 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tVMS-ified filespec is %s\n",
275 specdsc.dsc$a_pointer));
276 New(1399,dlptr,1,struct libref);
277 dlptr->name.dsc$b_dtype = dlptr->defspec.dsc$b_dtype = DSC$K_DTYPE_T;
278 dlptr->name.dsc$b_class = dlptr->defspec.dsc$b_class = DSC$K_CLASS_S;
279 sts = sys$filescan(&specdsc,namlst,0);
280 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tsys$filescan: returns %d, name is %.*s\n",
281 sts,namlst[0].len,namlst[0].string));
287 dlptr->name.dsc$w_length = namlst[0].len;
288 dlptr->name.dsc$a_pointer = savepvn(namlst[0].string,namlst[0].len);
289 dlptr->defspec.dsc$w_length = specdsc.dsc$w_length - namlst[0].len;
290 New(1097, dlptr->defspec.dsc$a_pointer, dlptr->defspec.dsc$w_length + 1, char);
291 deflen = namlst[0].string - specdsc.dsc$a_pointer;
292 memcpy(dlptr->defspec.dsc$a_pointer,specdsc.dsc$a_pointer,deflen);
293 memcpy(dlptr->defspec.dsc$a_pointer + deflen,
294 namlst[0].string + namlst[0].len,
295 dlptr->defspec.dsc$w_length - deflen);
296 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tlibref = name: %s, defspec: %.*s\n",
297 dlptr->name.dsc$a_pointer,
298 dlptr->defspec.dsc$w_length,
299 dlptr->defspec.dsc$a_pointer));
300 if (!(reqSVhndl = av_fetch(dl_require_symbols,0,FALSE)) || !(reqSV = *reqSVhndl)) {
301 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\t@dl_require_symbols empty, returning untested libref\n"));
304 symdsc.dsc$w_length = SvCUR(reqSV);
305 symdsc.dsc$a_pointer = SvPVX(reqSV);
306 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\t$dl_require_symbols[0] = %.*s\n",
307 symdsc.dsc$w_length, symdsc.dsc$a_pointer));
308 sts = my_find_image_symbol(&(dlptr->name),&symdsc,
309 &entry,&(dlptr->defspec));
310 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tlib$find_image_symbol returns %d\n",sts));
319 Safefree(dlptr->name.dsc$a_pointer);
320 Safefree(dlptr->defspec.dsc$a_pointer);
322 ST(0) = &PL_sv_undef;
325 ST(0) = sv_2mortal(newSViv(PTR2IV(dlptr)));
330 dl_find_symbol(librefptr,symname)
334 struct libref thislib = *((struct libref *)librefptr);
335 struct dsc$descriptor_s
336 symdsc = {SvCUR(symname),DSC$K_DTYPE_T,DSC$K_CLASS_S,SvPVX(symname)};
340 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_find_dymbol(%.*s,%.*s):\n",
341 thislib.name.dsc$w_length, thislib.name.dsc$a_pointer,
342 symdsc.dsc$w_length,symdsc.dsc$a_pointer));
343 sts = my_find_image_symbol(&(thislib.name),&symdsc,
344 &entry,&(thislib.defspec));
345 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tlib$find_image_symbol returns %d\n",sts));
346 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tentry point is %d\n",
347 (unsigned long int) entry));
349 /* error message already saved by findsym_handler */
350 ST(0) = &PL_sv_undef;
352 else ST(0) = sv_2mortal(newSViv(PTR2IV(entry)));
360 # These functions should not need changing on any platform:
363 dl_install_xsub(perl_name, symref, filename="$Package")
368 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "dl_install_xsub(name=%s, symref=%x)\n",
370 ST(0) = sv_2mortal(newRV((SV*)newXS(perl_name,
371 (void(*)(pTHX_ CV *))symref,
379 RETVAL = dl_last_error ;