Commit | Line | Data |
---|---|---|
4a655e50 | 1 | /* Copyright (C) 1995,1996,1997,1998,2000,2001, 2003, 2004, 2006, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. |
0f2d19dd | 2 | * |
73be1d9e | 3 | * This library is free software; you can redistribute it and/or |
53befeb7 NJ |
4 | * modify it under the terms of the GNU Lesser General Public License |
5 | * as published by the Free Software Foundation; either version 3 of | |
6 | * the License, or (at your option) any later version. | |
0f2d19dd | 7 | * |
53befeb7 NJ |
8 | * This library is distributed in the hope that it will be useful, but |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
73be1d9e MV |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
11 | * Lesser General Public License for more details. | |
0f2d19dd | 12 | * |
73be1d9e MV |
13 | * You should have received a copy of the GNU Lesser General Public |
14 | * License along with this library; if not, write to the Free Software | |
53befeb7 NJ |
15 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
16 | * 02110-1301 USA | |
73be1d9e | 17 | */ |
1bbd0b84 | 18 | |
1bbd0b84 | 19 | |
0f2d19dd | 20 | \f |
dbb605f5 LC |
21 | #ifdef HAVE_CONFIG_H |
22 | # include <config.h> | |
23 | #endif | |
0f2d19dd JB |
24 | |
25 | #include <stdio.h> | |
27646f41 | 26 | #include <unistdio.h> |
a0599745 MD |
27 | #include "libguile/_scm.h" |
28 | #include "libguile/smob.h" | |
a0599745 MD |
29 | #include "libguile/eval.h" |
30 | #include "libguile/eq.h" | |
416f26c7 | 31 | #include "libguile/control.h" |
e10cf6b9 | 32 | #include "libguile/deprecation.h" |
a0599745 | 33 | #include "libguile/backtrace.h" |
a0599745 | 34 | #include "libguile/debug.h" |
a0599745 MD |
35 | #include "libguile/stackchk.h" |
36 | #include "libguile/stacks.h" | |
37 | #include "libguile/fluids.h" | |
38 | #include "libguile/ports.h" | |
a0599745 | 39 | #include "libguile/validate.h" |
416f26c7 | 40 | #include "libguile/vm.h" |
a0599745 | 41 | #include "libguile/throw.h" |
9de87eea | 42 | #include "libguile/init.h" |
a2c40dc7 | 43 | #include "libguile/strings.h" |
0f2d19dd | 44 | |
22fc179a HWN |
45 | #include "libguile/private-options.h" |
46 | ||
47 | ||
416f26c7 AW |
48 | /* Pleasantly enough, the guts of catch are defined in Scheme, in terms of |
49 | prompt, abort, and the %exception-handler fluid. This file just provides | |
50 | shims so that it's easy to have catch functionality from C. | |
0f2d19dd | 51 | |
416f26c7 AW |
52 | All of these function names and prototypes carry a fair bit of historical |
53 | baggage. */ | |
c209c88e | 54 | |
0f2d19dd | 55 | |
416f26c7 AW |
56 | #define CACHE_VAR(var,name) \ |
57 | static SCM var = SCM_BOOL_F; \ | |
58 | if (scm_is_false (var)) \ | |
59 | { \ | |
60 | var = scm_module_variable (scm_the_root_module (), \ | |
9179e8a5 | 61 | scm_from_latin1_symbol (name)); \ |
416f26c7 AW |
62 | if (scm_is_false (var)) \ |
63 | abort (); \ | |
64 | } | |
0f2d19dd | 65 | |
416f26c7 AW |
66 | \f |
67 | ||
68 | SCM | |
69 | scm_catch (SCM key, SCM thunk, SCM handler) | |
0f2d19dd | 70 | { |
416f26c7 AW |
71 | CACHE_VAR (var, "catch"); |
72 | ||
73 | return scm_call_3 (scm_variable_ref (var), key, thunk, handler); | |
0f2d19dd JB |
74 | } |
75 | ||
416f26c7 AW |
76 | SCM |
77 | scm_catch_with_pre_unwind_handler (SCM key, SCM thunk, SCM handler, | |
78 | SCM pre_unwind_handler) | |
0f2d19dd | 79 | { |
416f26c7 AW |
80 | if (SCM_UNBNDP (pre_unwind_handler)) |
81 | return scm_catch (key, thunk, handler); | |
82 | else | |
83 | { | |
84 | CACHE_VAR (var, "catch"); | |
85 | ||
86 | return scm_call_4 (scm_variable_ref (var), key, thunk, handler, | |
87 | pre_unwind_handler); | |
88 | } | |
0f2d19dd JB |
89 | } |
90 | ||
416f26c7 AW |
91 | SCM |
92 | scm_with_throw_handler (SCM key, SCM thunk, SCM handler) | |
93 | { | |
94 | CACHE_VAR (var, "with-throw-handler"); | |
95 | ||
96 | return scm_call_3 (scm_variable_ref (var), key, thunk, handler); | |
97 | } | |
74229f75 | 98 | |
416f26c7 AW |
99 | SCM |
100 | scm_throw (SCM key, SCM args) | |
0f2d19dd | 101 | { |
416f26c7 AW |
102 | CACHE_VAR (var, "throw"); |
103 | ||
104 | return scm_apply_1 (scm_variable_ref (var), key, args); | |
105 | } | |
106 | ||
107 | \f | |
0f2d19dd | 108 | |
416f26c7 | 109 | /* Now some support for C bodies and catch handlers */ |
650fa1ab | 110 | |
416f26c7 | 111 | static scm_t_bits tc16_catch_closure; |
43e01b1e | 112 | |
416f26c7 AW |
113 | enum { |
114 | CATCH_CLOSURE_BODY, | |
115 | CATCH_CLOSURE_HANDLER | |
43e01b1e NJ |
116 | }; |
117 | ||
416f26c7 AW |
118 | static SCM |
119 | make_catch_body_closure (scm_t_catch_body body, void *body_data) | |
120 | { | |
121 | SCM ret; | |
122 | SCM_NEWSMOB2 (ret, tc16_catch_closure, body, body_data); | |
123 | SCM_SET_SMOB_FLAGS (ret, CATCH_CLOSURE_BODY); | |
124 | return ret; | |
125 | } | |
126 | ||
127 | static SCM | |
128 | make_catch_handler_closure (scm_t_catch_handler handler, void *handler_data) | |
129 | { | |
130 | SCM ret; | |
131 | SCM_NEWSMOB2 (ret, tc16_catch_closure, handler, handler_data); | |
132 | SCM_SET_SMOB_FLAGS (ret, CATCH_CLOSURE_HANDLER); | |
133 | return ret; | |
134 | } | |
43e01b1e | 135 | |
416f26c7 AW |
136 | static SCM |
137 | apply_catch_closure (SCM clo, SCM args) | |
138 | { | |
139 | void *data = (void*)SCM_SMOB_DATA_2 (clo); | |
650fa1ab | 140 | |
416f26c7 AW |
141 | switch (SCM_SMOB_FLAGS (clo)) |
142 | { | |
143 | case CATCH_CLOSURE_BODY: | |
144 | { | |
145 | scm_t_catch_body body = (void*)SCM_SMOB_DATA (clo); | |
146 | return body (data); | |
147 | } | |
148 | case CATCH_CLOSURE_HANDLER: | |
149 | { | |
150 | scm_t_catch_handler handler = (void*)SCM_SMOB_DATA (clo); | |
151 | return handler (data, scm_car (args), scm_cdr (args)); | |
152 | } | |
153 | default: | |
154 | abort (); | |
155 | } | |
156 | } | |
650fa1ab | 157 | |
416f26c7 | 158 | /* TAG is the catch tag. Typically, this is a symbol, but this |
650fa1ab JB |
159 | function doesn't actually care about that. |
160 | ||
161 | BODY is a pointer to a C function which runs the body of the catch; | |
162 | this is the code you can throw from. We call it like this: | |
19b27fa2 | 163 | BODY (BODY_DATA) |
650fa1ab | 164 | where: |
816a6f06 JB |
165 | BODY_DATA is just the BODY_DATA argument we received; we pass it |
166 | through to BODY as its first argument. The caller can make | |
167 | BODY_DATA point to anything useful that BODY might need. | |
650fa1ab JB |
168 | |
169 | HANDLER is a pointer to a C function to deal with a throw to TAG, | |
170 | should one occur. We call it like this: | |
86327304 | 171 | HANDLER (HANDLER_DATA, THROWN_TAG, THROW_ARGS) |
650fa1ab | 172 | where |
816a6f06 JB |
173 | HANDLER_DATA is the HANDLER_DATA argument we recevied; it's the |
174 | same idea as BODY_DATA above. | |
86327304 JB |
175 | THROWN_TAG is the tag that the user threw to; usually this is |
176 | TAG, but it could be something else if TAG was #t (i.e., a | |
177 | catch-all), or the user threw to a jmpbuf. | |
650fa1ab | 178 | THROW_ARGS is the list of arguments the user passed to the THROW |
4dd8323f | 179 | function, after the tag. |
650fa1ab | 180 | |
3eed3475 JB |
181 | BODY_DATA is just a pointer we pass through to BODY. HANDLER_DATA |
182 | is just a pointer we pass through to HANDLER. We don't actually | |
183 | use either of those pointers otherwise ourselves. The idea is | |
184 | that, if our caller wants to communicate something to BODY or | |
185 | HANDLER, it can pass a pointer to it as MUMBLE_DATA, which BODY and | |
186 | HANDLER can then use. Think of it as a way to make BODY and | |
187 | HANDLER closures, not just functions; MUMBLE_DATA points to the | |
188 | enclosed variables. | |
189 | ||
190 | Of course, it's up to the caller to make sure that any data a | |
191 | MUMBLE_DATA needs is protected from GC. A common way to do this is | |
192 | to make MUMBLE_DATA a pointer to data stored in an automatic | |
193 | structure variable; since the collector must scan the stack for | |
194 | references anyway, this assures that any references in MUMBLE_DATA | |
195 | will be found. */ | |
650fa1ab | 196 | |
0f2d19dd | 197 | SCM |
43e01b1e NJ |
198 | scm_c_catch (SCM tag, |
199 | scm_t_catch_body body, void *body_data, | |
200 | scm_t_catch_handler handler, void *handler_data, | |
201 | scm_t_catch_handler pre_unwind_handler, void *pre_unwind_handler_data) | |
0f2d19dd | 202 | { |
416f26c7 AW |
203 | SCM sbody, shandler, spre_unwind_handler; |
204 | ||
205 | sbody = make_catch_body_closure (body, body_data); | |
206 | shandler = make_catch_handler_closure (handler, handler_data); | |
207 | if (pre_unwind_handler) | |
208 | spre_unwind_handler = make_catch_handler_closure (pre_unwind_handler, | |
209 | pre_unwind_handler_data); | |
0f2d19dd | 210 | else |
416f26c7 AW |
211 | spre_unwind_handler = SCM_UNDEFINED; |
212 | ||
213 | return scm_catch_with_pre_unwind_handler (tag, sbody, shandler, | |
214 | spre_unwind_handler); | |
0f2d19dd JB |
215 | } |
216 | ||
43e01b1e NJ |
217 | SCM |
218 | scm_internal_catch (SCM tag, | |
219 | scm_t_catch_body body, void *body_data, | |
220 | scm_t_catch_handler handler, void *handler_data) | |
221 | { | |
416f26c7 AW |
222 | return scm_c_catch (tag, |
223 | body, body_data, | |
224 | handler, handler_data, | |
225 | NULL, NULL); | |
18eadcbe JB |
226 | } |
227 | ||
18eadcbe | 228 | |
18eadcbe | 229 | SCM |
43e01b1e NJ |
230 | scm_c_with_throw_handler (SCM tag, |
231 | scm_t_catch_body body, | |
232 | void *body_data, | |
233 | scm_t_catch_handler handler, | |
234 | void *handler_data, | |
235 | int lazy_catch_p) | |
18eadcbe | 236 | { |
416f26c7 | 237 | SCM sbody, shandler; |
18eadcbe | 238 | |
e10cf6b9 AW |
239 | if (lazy_catch_p) |
240 | scm_c_issue_deprecation_warning | |
241 | ("The LAZY_CATCH_P argument to `scm_c_with_throw_handler' is no longer.\n" | |
242 | "supported. Instead the handler will be invoked from within the dynamic\n" | |
243 | "context of the corresponding `throw'.\n" | |
244 | "\nTHIS COULD CHANGE YOUR PROGRAM'S BEHAVIOR.\n\n" | |
245 | "Please modify your program to pass 0 as the LAZY_CATCH_P argument,\n" | |
246 | "and adapt it (if necessary) to expect to be within the dynamic context\n" | |
247 | "of the throw."); | |
248 | ||
416f26c7 AW |
249 | sbody = make_catch_body_closure (body, body_data); |
250 | shandler = make_catch_handler_closure (handler, handler_data); | |
251 | ||
252 | return scm_with_throw_handler (tag, sbody, shandler); | |
18eadcbe JB |
253 | } |
254 | ||
95384717 | 255 | \f |
95384717 | 256 | /* body and handler functions for use with any of the above catch variants */ |
18eadcbe | 257 | |
816a6f06 | 258 | /* This is a body function you can pass to scm_internal_catch if you |
492960a4 | 259 | want the body to be like Scheme's `catch' --- a thunk. |
650fa1ab | 260 | |
74229f75 JB |
261 | BODY_DATA is a pointer to a scm_body_thunk_data structure, which |
262 | contains the Scheme procedure to invoke as the body, and the tag | |
492960a4 | 263 | we're catching. */ |
650fa1ab | 264 | |
816a6f06 | 265 | SCM |
6e8d25a6 | 266 | scm_body_thunk (void *body_data) |
650fa1ab | 267 | { |
816a6f06 | 268 | struct scm_body_thunk_data *c = (struct scm_body_thunk_data *) body_data; |
650fa1ab | 269 | |
fdc28395 | 270 | return scm_call_0 (c->body_proc); |
650fa1ab JB |
271 | } |
272 | ||
273 | ||
74229f75 | 274 | /* This is a handler function you can pass to scm_internal_catch if |
4dd8323f JB |
275 | you want the handler to act like Scheme's catch: (throw TAG ARGS ...) |
276 | applies a handler procedure to (TAG ARGS ...). | |
74229f75 JB |
277 | |
278 | If the user does a throw to this catch, this function runs a | |
816a6f06 JB |
279 | handler procedure written in Scheme. HANDLER_DATA is a pointer to |
280 | an SCM variable holding the Scheme procedure object to invoke. It | |
74229f75 JB |
281 | ought to be a pointer to an automatic variable (i.e., one living on |
282 | the stack), or the procedure object should be otherwise protected | |
283 | from GC. */ | |
816a6f06 | 284 | SCM |
6e8d25a6 | 285 | scm_handle_by_proc (void *handler_data, SCM tag, SCM throw_args) |
650fa1ab | 286 | { |
816a6f06 | 287 | SCM *handler_proc_p = (SCM *) handler_data; |
650fa1ab | 288 | |
fdc28395 | 289 | return scm_apply_1 (*handler_proc_p, tag, throw_args); |
650fa1ab JB |
290 | } |
291 | ||
1345df5d MV |
292 | /* SCM_HANDLE_BY_PROC_CATCHING_ALL is like SCM_HANDLE_BY_PROC but |
293 | catches all throws that the handler might emit itself. The handler | |
294 | used for these `secondary' throws is SCM_HANDLE_BY_MESSAGE_NO_EXIT. */ | |
295 | ||
296 | struct hbpca_data { | |
297 | SCM proc; | |
298 | SCM args; | |
299 | }; | |
300 | ||
301 | static SCM | |
6e8d25a6 | 302 | hbpca_body (void *body_data) |
1345df5d MV |
303 | { |
304 | struct hbpca_data *data = (struct hbpca_data *)body_data; | |
fdc28395 | 305 | return scm_apply_0 (data->proc, data->args); |
1345df5d MV |
306 | } |
307 | ||
308 | SCM | |
6e8d25a6 | 309 | scm_handle_by_proc_catching_all (void *handler_data, SCM tag, SCM throw_args) |
1345df5d MV |
310 | { |
311 | SCM *handler_proc_p = (SCM *) handler_data; | |
312 | struct hbpca_data data; | |
313 | data.proc = *handler_proc_p; | |
314 | data.args = scm_cons (tag, throw_args); | |
315 | ||
316 | return scm_internal_catch (SCM_BOOL_T, | |
317 | hbpca_body, &data, | |
318 | scm_handle_by_message_noexit, NULL); | |
319 | } | |
650fa1ab | 320 | |
f032b8a8 JB |
321 | /* Derive the an exit status from the arguments to (quit ...). */ |
322 | int | |
6e8d25a6 | 323 | scm_exit_status (SCM args) |
f032b8a8 | 324 | { |
c96d76b8 | 325 | if (!SCM_NULL_OR_NIL_P (args)) |
f032b8a8 JB |
326 | { |
327 | SCM cqa = SCM_CAR (args); | |
328 | ||
e11e83f3 MV |
329 | if (scm_is_integer (cqa)) |
330 | return (scm_to_int (cqa)); | |
7888309b | 331 | else if (scm_is_false (cqa)) |
f032b8a8 JB |
332 | return 1; |
333 | } | |
334 | return 0; | |
335 | } | |
336 | ||
74229f75 | 337 | |
e0c70a8b AW |
338 | static int |
339 | should_print_backtrace (SCM tag, SCM stack) | |
340 | { | |
341 | return SCM_BACKTRACE_P | |
342 | && scm_is_true (stack) | |
343 | && scm_initialized_p | |
344 | /* It's generally not useful to print backtraces for errors reading | |
345 | or expanding code in these fallback catch statements. */ | |
346 | && !scm_is_eq (tag, scm_from_latin1_symbol ("read-error")) | |
347 | && !scm_is_eq (tag, scm_from_latin1_symbol ("syntax-error")); | |
348 | } | |
349 | ||
f032b8a8 JB |
350 | static void |
351 | handler_message (void *handler_data, SCM tag, SCM args) | |
e68b42c1 | 352 | { |
e0c70a8b | 353 | SCM p, stack, frame; |
650fa1ab | 354 | |
e0c70a8b | 355 | p = scm_current_error_port (); |
39d41afe AW |
356 | /* Usually we get here via a throw to a catch-all. In that case |
357 | there is the throw frame active, and the catch closure, so narrow by | |
358 | two frames. It is possible for a user to invoke | |
359 | scm_handle_by_message directly, though, so it could be this | |
360 | narrows too much. We'll have to see how this works out in | |
361 | practice. */ | |
362 | stack = scm_make_stack (SCM_BOOL_T, scm_list_1 (scm_from_int (2))); | |
e0c70a8b | 363 | frame = scm_is_true (stack) ? scm_stack_ref (stack, SCM_INUM0) : SCM_BOOL_F; |
eeb48bc2 | 364 | |
e0c70a8b | 365 | if (should_print_backtrace (tag, stack)) |
74229f75 | 366 | { |
e0c70a8b AW |
367 | scm_puts ("Backtrace:\n", p); |
368 | scm_display_backtrace_with_highlights (stack, p, | |
369 | SCM_BOOL_F, SCM_BOOL_F, | |
370 | SCM_EOL); | |
371 | scm_newline (p); | |
74229f75 | 372 | } |
f64056d1 | 373 | |
e0c70a8b | 374 | scm_print_exception (p, frame, tag, args); |
f032b8a8 JB |
375 | } |
376 | ||
377 | ||
378 | /* This is a handler function to use if you want scheme to print a | |
379 | message and die. Useful for dealing with throws to uncaught keys | |
380 | at the top level. | |
381 | ||
382 | At boot time, we establish a catch-all that uses this as its handler. | |
383 | 1) If the user wants something different, they can use (catch #t | |
384 | ...) to do what they like. | |
385 | 2) Outside the context of a read-eval-print loop, there isn't | |
386 | anything else good to do; libguile should not assume the existence | |
387 | of a read-eval-print loop. | |
388 | 3) Given that we shouldn't do anything complex, it's much more | |
389 | robust to do it in C code. | |
390 | ||
391 | HANDLER_DATA, if non-zero, is assumed to be a char * pointing to a | |
392 | message header to print; if zero, we use "guile" instead. That | |
393 | text is followed by a colon, then the message described by ARGS. */ | |
394 | ||
5a2a5407 DH |
395 | /* Dirk:FIXME:: The name of the function should make clear that the |
396 | * application gets terminated. | |
397 | */ | |
398 | ||
f032b8a8 | 399 | SCM |
6e8d25a6 | 400 | scm_handle_by_message (void *handler_data, SCM tag, SCM args) |
f032b8a8 | 401 | { |
4a655e50 | 402 | if (scm_is_true (scm_eq_p (tag, scm_from_latin1_symbol ("quit")))) |
9de87eea | 403 | exit (scm_exit_status (args)); |
f032b8a8 JB |
404 | |
405 | handler_message (handler_data, tag, args); | |
9de87eea | 406 | scm_i_pthread_exit (NULL); |
23f2b9a3 KR |
407 | |
408 | /* this point not reached, but suppress gcc warning about no return value | |
409 | in case scm_i_pthread_exit isn't marked as "noreturn" (which seemed not | |
410 | to be the case on cygwin for instance) */ | |
411 | return SCM_BOOL_F; | |
74229f75 JB |
412 | } |
413 | ||
414 | ||
f032b8a8 JB |
415 | /* This is just like scm_handle_by_message, but it doesn't exit; it |
416 | just returns #f. It's useful in cases where you don't really know | |
417 | enough about the body to handle things in a better way, but don't | |
418 | want to let throws fall off the bottom of the wind list. */ | |
419 | SCM | |
6e8d25a6 | 420 | scm_handle_by_message_noexit (void *handler_data, SCM tag, SCM args) |
74229f75 | 421 | { |
4a655e50 | 422 | if (scm_is_true (scm_eq_p (tag, scm_from_latin1_symbol ("quit")))) |
9de87eea MV |
423 | exit (scm_exit_status (args)); |
424 | ||
f032b8a8 JB |
425 | handler_message (handler_data, tag, args); |
426 | ||
427 | return SCM_BOOL_F; | |
e68b42c1 MD |
428 | } |
429 | ||
3eed3475 | 430 | |
e158e4f4 | 431 | SCM |
e81d98ec | 432 | scm_handle_by_throw (void *handler_data SCM_UNUSED, SCM tag, SCM args) |
e158e4f4 MD |
433 | { |
434 | scm_ithrow (tag, args, 1); | |
435 | return SCM_UNSPECIFIED; /* never returns */ | |
436 | } | |
437 | ||
43e01b1e | 438 | SCM |
36c40440 | 439 | scm_ithrow (SCM key, SCM args, int no_return SCM_UNUSED) |
ad310508 | 440 | { |
416f26c7 | 441 | return scm_throw (key, args); |
ad310508 MD |
442 | } |
443 | ||
416f26c7 AW |
444 | /* Unfortunately we have to support catch and throw before boot-9 has, um, |
445 | booted. So here are lame versions, which will get replaced with their scheme | |
446 | equivalents. */ | |
c6a32a2c AW |
447 | |
448 | SCM_SYMBOL (sym_pre_init_catch_tag, "%pre-init-catch-tag"); | |
449 | ||
416f26c7 AW |
450 | static SCM |
451 | pre_init_catch (SCM tag, SCM thunk, SCM handler, SCM pre_unwind_handler) | |
0f2d19dd | 452 | { |
416f26c7 | 453 | SCM vm, prompt, res; |
492960a4 | 454 | |
416f26c7 AW |
455 | /* Only handle catch-alls without pre-unwind handlers */ |
456 | if (!SCM_UNBNDP (pre_unwind_handler)) | |
457 | abort (); | |
458 | if (scm_is_false (scm_eqv_p (tag, SCM_BOOL_T))) | |
d6580119 | 459 | abort (); |
43e01b1e | 460 | |
416f26c7 | 461 | vm = scm_the_vm (); |
c6a32a2c | 462 | prompt = scm_c_make_prompt (sym_pre_init_catch_tag, |
416f26c7 | 463 | SCM_VM_DATA (vm)->fp, SCM_VM_DATA (vm)->sp, |
adbdfd6d AW |
464 | SCM_VM_DATA (vm)->ip, 1, -1, scm_i_dynwinds ()); |
465 | scm_i_set_dynwinds (scm_cons (prompt, SCM_PROMPT_DYNWINDS (prompt))); | |
43e01b1e | 466 | |
416f26c7 AW |
467 | if (SCM_PROMPT_SETJMP (prompt)) |
468 | { | |
469 | /* nonlocal exit */ | |
572eef50 | 470 | SCM args = scm_i_prompt_pop_abort_args_x (vm); |
416f26c7 AW |
471 | /* cdr past the continuation */ |
472 | return scm_apply_0 (handler, scm_cdr (args)); | |
11702758 | 473 | } |
3eed3475 | 474 | |
416f26c7 AW |
475 | res = scm_call_0 (thunk); |
476 | scm_i_set_dynwinds (scm_cdr (scm_i_dynwinds ())); | |
346e4402 | 477 | |
416f26c7 | 478 | return res; |
0f2d19dd JB |
479 | } |
480 | ||
5a588521 AW |
481 | static int |
482 | find_pre_init_catch (void) | |
483 | { | |
484 | SCM winds; | |
485 | ||
486 | /* Search the wind list for an appropriate prompt. | |
487 | "Waiter, please bring us the wind list." */ | |
488 | for (winds = scm_i_dynwinds (); scm_is_pair (winds); winds = SCM_CDR (winds)) | |
489 | if (SCM_PROMPT_P (SCM_CAR (winds)) | |
490 | && scm_is_eq (SCM_PROMPT_TAG (SCM_CAR (winds)), sym_pre_init_catch_tag)) | |
491 | return 1; | |
492 | ||
493 | return 0; | |
494 | } | |
495 | ||
416f26c7 | 496 | static SCM |
5a588521 | 497 | pre_init_throw (SCM k, SCM args) |
416f26c7 | 498 | { |
5a588521 AW |
499 | if (find_pre_init_catch ()) |
500 | return scm_at_abort (sym_pre_init_catch_tag, scm_cons (k, args)); | |
501 | else | |
502 | { | |
cd4f274c AW |
503 | static int error_printing_error = 0; |
504 | static int error_printing_fallback = 0; | |
505 | ||
506 | if (error_printing_fallback) | |
507 | fprintf (stderr, "\nFailed to print exception.\n"); | |
508 | else if (error_printing_error) | |
509 | { | |
510 | fprintf (stderr, "\nError while printing exception:\n"); | |
511 | error_printing_fallback = 1; | |
512 | fprintf (stderr, "Key: "); | |
513 | scm_write (k, scm_current_error_port ()); | |
514 | fprintf (stderr, ", args: "); | |
515 | scm_write (args, scm_current_error_port ()); | |
516 | scm_newline (scm_current_error_port ()); | |
517 | } | |
518 | else | |
519 | { | |
520 | fprintf (stderr, "Throw without catch before boot:\n"); | |
521 | error_printing_error = 1; | |
522 | scm_handle_by_message_noexit (NULL, k, args); | |
523 | } | |
524 | ||
e7450642 AW |
525 | fprintf (stderr, "Aborting.\n"); |
526 | abort (); | |
5a588521 AW |
527 | return SCM_BOOL_F; /* not reached */ |
528 | } | |
416f26c7 | 529 | } |
0f2d19dd | 530 | |
0f2d19dd JB |
531 | void |
532 | scm_init_throw () | |
0f2d19dd | 533 | { |
416f26c7 AW |
534 | tc16_catch_closure = scm_make_smob_type ("catch-closure", 0); |
535 | scm_set_smob_apply (tc16_catch_closure, apply_catch_closure, 0, 0, 1); | |
e841c3e0 | 536 | |
416f26c7 | 537 | scm_c_define ("catch", scm_c_make_gsubr ("catch", 3, 1, 0, pre_init_catch)); |
5a588521 | 538 | scm_c_define ("throw", scm_c_make_gsubr ("throw", 1, 0, 1, pre_init_throw)); |
e841c3e0 | 539 | |
a0599745 | 540 | #include "libguile/throw.x" |
0f2d19dd | 541 | } |
89e00824 ML |
542 | |
543 | /* | |
544 | Local Variables: | |
545 | c-file-style: "gnu" | |
546 | End: | |
547 | */ |