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$find_image_symbol would use if
38 * it were passed a given file specification. The file specification passed
39 * to dl_expandspec() and dl_load_file() can be partial or complete, and can
40 * use VMS or Unix syntax; these routines perform the necessary conversions.
41 * In general, writers of perl extensions need only conform to the
42 * procedures set out in the DynaLoader documentation, and let the details
43 * be taken care of by the routines here and in DynaLoader.pm. If anyone
44 * comes across any incompatibilities, please let me know. Thanks.
52 #include "dlutils.c" /* dl_debug, LastError; SaveError not used */
54 static AV *dl_require_symbols = Nullav;
57 * dl_debug and LastError are static vars; you'll need to deal
58 * with them appropriately if you need context independence
63 #include <lib$routines.h>
68 typedef unsigned long int vmssts;
71 struct dsc$descriptor_s name;
72 struct dsc$descriptor_s defspec;
75 /* Static data for dl_expand_filespec() - This is static to save
76 * initialization on each call; if you need context-independence,
77 * just make these auto variables in dl_expandspec() and dl_load_file()
79 static char dlesa[NAM$C_MAXRSS], dlrsa[NAM$C_MAXRSS];
80 static struct FAB dlfab;
81 static struct NAM dlnam;
83 /* $PutMsg action routine - records error message in LastError */
85 copy_errmsg(msg,unused)
86 struct dsc$descriptor_s * msg;
89 if (*(msg->dsc$a_pointer) == '%') { /* first line */
91 strncpy((LastError = saferealloc(LastError,msg->dsc$w_length+1)),
92 msg->dsc$a_pointer, msg->dsc$w_length);
94 strncpy((LastError = safemalloc(msg->dsc$w_length+1)),
95 msg->dsc$a_pointer, msg->dsc$w_length);
96 LastError[msg->dsc$w_length] = '\0';
98 else { /* continuation line */
99 int errlen = strlen(LastError);
100 LastError = saferealloc(LastError, errlen + msg->dsc$w_length + 2);
101 LastError[errlen] = '\n'; LastError[errlen+1] = '\0';
102 strncat(LastError, msg->dsc$a_pointer, msg->dsc$w_length);
103 LastError[errlen+msg->dsc$w_length+1] = '\0';
108 /* Use $PutMsg to retrieve error message for failure status code */
110 dl_set_error(sts,stv)
116 vec[0] = stv ? 2 : 1;
117 vec[1] = sts; vec[2] = stv;
118 _ckvmssts(sys$putmsg(vec,copy_errmsg,0,0));
122 findsym_handler(void *sig, void *mech)
124 unsigned long int myvec[8],args, *usig = (unsigned long int *) sig;
125 /* Be paranoid and assume signal vector passed in might be readonly */
126 myvec[0] = args = usig[0] > 10 ? 9 : usig[0] - 1;
127 while (--args) myvec[args] = usig[args];
128 _ckvmssts(sys$putmsg(myvec,copy_errmsg,0,0));
129 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "findsym_handler: received\n\t%s\n",LastError));
133 /* wrapper for lib$find_image_symbol, so signalled errors can be saved
134 * for dl_error and then returned */
135 static unsigned long int
136 my_find_image_symbol(struct dsc$descriptor_s *imgname,
137 struct dsc$descriptor_s *symname,
139 struct dsc$descriptor_s *defspec)
141 unsigned long int retsts;
142 VAXC$ESTABLISH(findsym_handler);
143 retsts = lib$find_image_symbol(imgname,symname,entry,defspec);
149 dl_private_init(pTHX)
151 dl_generic_private_init(aTHX);
152 dl_require_symbols = get_av("DynaLoader::dl_require_symbols", 0x4);
153 /* Set up the static control blocks for dl_expand_filespec() */
156 dlfab.fab$l_nam = &dlnam;
157 dlnam.nam$l_esa = dlesa;
158 dlnam.nam$b_ess = sizeof dlesa;
159 dlnam.nam$l_rsa = dlrsa;
160 dlnam.nam$b_rss = sizeof dlrsa;
162 MODULE = DynaLoader PACKAGE = DynaLoader
165 (void)dl_private_init(aTHX);
168 dl_expandspec(filespec)
171 char vmsspec[NAM$C_MAXRSS], defspec[NAM$C_MAXRSS];
175 tovmsspec(filespec,vmsspec);
176 dlfab.fab$l_fna = vmsspec;
177 dlfab.fab$b_fns = strlen(vmsspec);
180 DLDEBUG(1,PerlIO_printf(PerlIO_stderr(), "dl_expand_filespec(%s):\n",vmsspec));
181 /* On the first pass, just parse the specification string */
182 dlnam.nam$b_nop = NAM$M_SYNCHK;
183 sts = sys$parse(&dlfab);
184 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\tSYNCHK sys$parse = %d\n",sts));
186 dl_set_error(dlfab.fab$l_sts,dlfab.fab$l_stv);
187 ST(0) = &PL_sv_undef;
190 /* Now set up a default spec - everything but the name */
191 deflen = dlnam.nam$l_name - dlesa;
192 memcpy(defspec,dlesa,deflen);
193 memcpy(defspec+deflen,dlnam.nam$l_type,
194 dlnam.nam$b_type + dlnam.nam$b_ver);
195 deflen += dlnam.nam$b_type + dlnam.nam$b_ver;
196 memcpy(vmsspec,dlnam.nam$l_name,dlnam.nam$b_name);
197 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\tsplit filespec: name = %.*s, default = %.*s\n",
198 dlnam.nam$b_name,vmsspec,deflen,defspec));
199 /* . . . and go back to expand it */
201 dlfab.fab$l_dna = defspec;
202 dlfab.fab$b_dns = deflen;
203 dlfab.fab$b_fns = dlnam.nam$b_name;
204 sts = sys$parse(&dlfab);
205 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\tname/default sys$parse = %d\n",sts));
207 dl_set_error(dlfab.fab$l_sts,dlfab.fab$l_stv);
208 ST(0) = &PL_sv_undef;
211 /* Now find the actual file */
212 sts = sys$search(&dlfab);
213 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\tsys$search = %d\n",sts));
215 dl_set_error(dlfab.fab$l_sts,dlfab.fab$l_stv);
216 ST(0) = &PL_sv_undef;
219 ST(0) = sv_2mortal(newSVpvn(dlnam.nam$l_rsa,dlnam.nam$b_rsl));
220 DLDEBUG(1,PerlIO_printf(PerlIO_stderr(), "\tresult = \\%.*s\\\n",
221 dlnam.nam$b_rsl,dlnam.nam$l_rsa));
227 dl_load_file(filespec, flags)
232 char vmsspec[NAM$C_MAXRSS];
233 SV *reqSV, **reqSVhndl;
235 struct dsc$descriptor_s
236 specdsc = {0, DSC$K_DTYPE_T, DSC$K_CLASS_S, 0},
237 symdsc = {0, DSC$K_DTYPE_T, DSC$K_CLASS_S, 0};
239 unsigned short int len;
240 unsigned short int code;
242 } namlst[2] = {{0,FSCN$_NAME,0},{0,0,0}};
243 struct libref *dlptr;
244 vmssts sts, failed = 0;
248 DLDEBUG(1,PerlIO_printf(PerlIO_stderr(), "dl_load_file(%s,%x):\n", filespec,flags));
249 specdsc.dsc$a_pointer = tovmsspec(filespec,vmsspec);
250 specdsc.dsc$w_length = strlen(specdsc.dsc$a_pointer);
251 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\tVMS-ified filespec is %s\n",
252 specdsc.dsc$a_pointer));
253 New(1399,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$filescan(&specdsc,namlst,0);
257 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\tsys$filescan: returns %d, name is %.*s\n",
258 sts,namlst[0].len,namlst[0].string));
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 New(1097, 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$w_length - deflen);
273 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\tlibref = name: %s, defspec: %.*s\n",
274 dlptr->name.dsc$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(PerlIO_stderr(), "\t@dl_require_symbols empty, returning untested libref\n"));
281 symdsc.dsc$w_length = SvCUR(reqSV);
282 symdsc.dsc$a_pointer = SvPVX(reqSV);
283 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\t$dl_require_symbols[0] = %.*s\n",
284 symdsc.dsc$w_length, symdsc.dsc$a_pointer));
285 sts = my_find_image_symbol(&(dlptr->name),&symdsc,
286 &entry,&(dlptr->defspec));
287 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\tlib$find_image_symbol returns %d\n",sts));
296 Safefree(dlptr->name.dsc$a_pointer);
297 Safefree(dlptr->defspec.dsc$a_pointer);
299 ST(0) = &PL_sv_undef;
302 ST(0) = sv_2mortal(newSViv((IV) dlptr));
307 dl_find_symbol(librefptr,symname)
311 struct libref thislib = *((struct libref *)librefptr);
312 struct dsc$descriptor_s
313 symdsc = {SvCUR(symname),DSC$K_DTYPE_T,DSC$K_CLASS_S,SvPVX(symname)};
317 DLDEBUG(1,PerlIO_printf(PerlIO_stderr(), "dl_find_dymbol(%.*s,%.*s):\n",
318 thislib.name.dsc$w_length, thislib.name.dsc$a_pointer,
319 symdsc.dsc$w_length,symdsc.dsc$a_pointer));
320 sts = my_find_image_symbol(&(thislib.name),&symdsc,
321 &entry,&(thislib.defspec));
322 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\tlib$find_image_symbol returns %d\n",sts));
323 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "\tentry point is %d\n",
324 (unsigned long int) entry));
326 /* error message already saved by findsym_handler */
327 ST(0) = &PL_sv_undef;
329 else ST(0) = sv_2mortal(newSViv((IV) entry));
337 # These functions should not need changing on any platform:
340 dl_install_xsub(perl_name, symref, filename="$Package")
345 DLDEBUG(2,PerlIO_printf(PerlIO_stderr(), "dl_install_xsub(name=%s, symref=%x)\n",
347 ST(0) = sv_2mortal(newRV((SV*)newXS(perl_name,
348 (void(*)(pTHX_ CV *))symref,