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7dc6e754 | 1 | /* Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc. |
0f2d19dd JB |
2 | * |
3 | * This program is free software; you can redistribute it and/or modify | |
4 | * it under the terms of the GNU General Public License as published by | |
5 | * the Free Software Foundation; either version 2, or (at your option) | |
6 | * any later version. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this software; see the file COPYING. If not, write to | |
82892bed JB |
15 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
16 | * Boston, MA 02111-1307 USA | |
0f2d19dd JB |
17 | * |
18 | * As a special exception, the Free Software Foundation gives permission | |
19 | * for additional uses of the text contained in its release of GUILE. | |
20 | * | |
21 | * The exception is that, if you link the GUILE library with other files | |
22 | * to produce an executable, this does not by itself cause the | |
23 | * resulting executable to be covered by the GNU General Public License. | |
24 | * Your use of that executable is in no way restricted on account of | |
25 | * linking the GUILE library code into it. | |
26 | * | |
27 | * This exception does not however invalidate any other reasons why | |
28 | * the executable file might be covered by the GNU General Public License. | |
29 | * | |
30 | * This exception applies only to the code released by the | |
31 | * Free Software Foundation under the name GUILE. If you copy | |
32 | * code from other Free Software Foundation releases into a copy of | |
33 | * GUILE, as the General Public License permits, the exception does | |
34 | * not apply to the code that you add in this way. To avoid misleading | |
35 | * anyone as to the status of such modified files, you must delete | |
36 | * this exception notice from them. | |
37 | * | |
38 | * If you write modifications of your own for GUILE, it is your choice | |
39 | * whether to permit this exception to apply to your modifications. | |
82892bed | 40 | * If you do not wish that, delete this exception notice. */ |
0f2d19dd JB |
41 | \f |
42 | ||
43 | #include <stdio.h> | |
44 | #include "_scm.h" | |
20e6290e | 45 | #include "stackchk.h" |
d564d753 MD |
46 | #include "dynwind.h" |
47 | #include "eval.h" | |
48 | #include "genio.h" | |
49 | #include "smob.h" | |
50 | #include "pairs.h" | |
51 | #include "throw.h" | |
d9dfcf80 | 52 | #include "fluids.h" |
0f2d19dd | 53 | |
20e6290e | 54 | #include "root.h" |
0f2d19dd JB |
55 | \f |
56 | ||
e71575d9 MV |
57 | /* Define this if you want to try out the stack allocation of cwdr's |
58 | jumpbuf. It works for me but I'm still worried that the dynwinds | |
59 | might be able to make a mess. */ | |
60 | ||
61 | #undef USE_STACKJMPBUF | |
62 | ||
0f2d19dd | 63 | SCM scm_sys_protects[SCM_NUM_PROTECTS]; |
d564d753 MD |
64 | |
65 | long scm_tc16_root; | |
66 | ||
67 | #ifndef USE_THREADS | |
68 | struct scm_root_state *scm_root; | |
69 | #endif | |
0f2d19dd JB |
70 | |
71 | \f | |
72 | ||
d564d753 MD |
73 | static SCM mark_root SCM_P ((SCM)); |
74 | ||
75 | static SCM | |
76 | mark_root (root) | |
77 | SCM root; | |
78 | { | |
79 | scm_root_state *s = SCM_ROOT_STATE (root); | |
dc53f026 | 80 | |
d564d753 MD |
81 | scm_gc_mark (s->rootcont); |
82 | scm_gc_mark (s->dynwinds); | |
83 | scm_gc_mark (s->continuation_stack); | |
84 | scm_gc_mark (s->continuation_stack_ptr); | |
85 | scm_gc_mark (s->progargs); | |
86 | scm_gc_mark (s->exitval); | |
87 | scm_gc_mark (s->cur_inp); | |
88 | scm_gc_mark (s->cur_outp); | |
89 | scm_gc_mark (s->cur_errp); | |
90 | scm_gc_mark (s->def_inp); | |
91 | scm_gc_mark (s->def_outp); | |
92 | scm_gc_mark (s->def_errp); | |
903073d5 | 93 | /* No need to gc mark def_loadp */ |
d9dfcf80 | 94 | scm_gc_mark (s->fluids); |
dc19d1d2 | 95 | scm_gc_mark (s->top_level_lookup_closure_var); |
d564d753 MD |
96 | scm_gc_mark (s->system_transformer); |
97 | return SCM_ROOT_STATE (root) -> parent; | |
98 | } | |
0f2d19dd | 99 | |
d564d753 MD |
100 | static scm_sizet free_root SCM_P ((SCM)); |
101 | ||
102 | static scm_sizet | |
103 | free_root (root) | |
104 | SCM root; | |
105 | { | |
106 | scm_must_free ((char *) SCM_ROOT_STATE (root)); | |
107 | return sizeof (scm_root_state); | |
108 | } | |
109 | ||
110 | static int print_root SCM_P ((SCM exp, SCM port, scm_print_state *pstate)); | |
111 | ||
112 | static int | |
113 | print_root (exp, port, pstate) | |
114 | SCM exp; | |
115 | SCM port; | |
116 | scm_print_state *pstate; | |
117 | { | |
b7f3516f | 118 | scm_puts ("#<root ", port); |
d564d753 | 119 | scm_intprint(SCM_SEQ (SCM_ROOT_STATE (exp) -> rootcont), 16, port); |
b7f3516f | 120 | scm_putc('>', port); |
d564d753 MD |
121 | return 1; |
122 | } | |
123 | ||
124 | static scm_smobfuns root_smob = | |
125 | { | |
126 | mark_root, | |
127 | free_root, | |
128 | print_root, | |
129 | 0 | |
130 | }; | |
131 | ||
132 | \f | |
133 | ||
134 | SCM | |
135 | scm_make_root (parent) | |
136 | SCM parent; | |
137 | { | |
138 | SCM root; | |
139 | scm_root_state *root_state; | |
140 | ||
141 | root_state = (scm_root_state *) scm_must_malloc (sizeof (scm_root_state), | |
142 | "scm_make_root"); | |
143 | if (SCM_NIMP (parent) && SCM_ROOTP (parent)) | |
144 | { | |
145 | memcpy (root_state, SCM_ROOT_STATE (parent), sizeof (scm_root_state)); | |
d9dfcf80 | 146 | scm_copy_fluids (root_state); |
d564d753 MD |
147 | root_state->parent = parent; |
148 | } | |
149 | else | |
150 | { | |
151 | root_state->parent = SCM_BOOL_F; | |
152 | } | |
153 | SCM_NEWCELL (root); | |
154 | SCM_REDEFER_INTS; | |
155 | SCM_SETCAR (root, scm_tc16_root); | |
156 | SCM_SETCDR (root, root_state); | |
157 | root_state->handle = root; | |
158 | SCM_REALLOW_INTS; | |
159 | return root; | |
160 | } | |
161 | ||
1cc91f1b | 162 | /* {call-with-dynamic-root} |
d564d753 MD |
163 | * |
164 | * Suspending the current thread to evaluate a thunk on the | |
165 | * same C stack but under a new root. | |
166 | * | |
1cc91f1b | 167 | * Calls to call-with-dynamic-root return exactly once (unless |
e71575d9 | 168 | * the process is somehow exitted). */ |
d564d753 | 169 | |
650fa1ab JB |
170 | /* Some questions about cwdr: |
171 | ||
172 | Couldn't the body just be a closure? Do we really need to pass | |
173 | args through to it? | |
174 | ||
175 | The semantics are a lot like catch's; in fact, we call | |
176 | scm_internal_catch to take care of that part of things. Wouldn't | |
177 | it be cleaner to say that uncaught throws just disappear into the | |
178 | ether (or print a message to stderr), and let the caller use catch | |
179 | themselves if they want to? | |
180 | ||
181 | -JimB */ | |
182 | ||
d564d753 MD |
183 | #if 0 |
184 | SCM scm_exitval; /* INUM with return value */ | |
185 | #endif | |
186 | static int n_dynamic_roots = 0; | |
187 | ||
650fa1ab | 188 | |
e71575d9 MV |
189 | /* cwdr fills out both of these structures, and then passes a pointer |
190 | to them through scm_internal_catch to the cwdr_body and | |
191 | cwdr_handler functions, to tell them how to behave and to get | |
192 | information back from them. | |
650fa1ab JB |
193 | |
194 | A cwdr is a lot like a catch, except there is no tag (all | |
195 | exceptions are caught), and the body procedure takes the arguments | |
e71575d9 MV |
196 | passed to cwdr as A1 and ARGS. The handler is also special since |
197 | it is not directly run from scm_internal_catch. It is executed | |
198 | outside the new dynamic root. */ | |
650fa1ab JB |
199 | |
200 | struct cwdr_body_data { | |
650fa1ab JB |
201 | /* Arguments to pass to the cwdr body function. */ |
202 | SCM a1, args; | |
203 | ||
204 | /* Scheme procedure to use as body of cwdr. */ | |
205 | SCM body_proc; | |
e71575d9 MV |
206 | }; |
207 | ||
208 | struct cwdr_handler_data { | |
209 | /* Do we need to run the handler? */ | |
210 | int run_handler; | |
f032b8a8 | 211 | |
e71575d9 MV |
212 | /* The tag and args to pass it. */ |
213 | SCM tag, args; | |
650fa1ab JB |
214 | }; |
215 | ||
216 | ||
217 | /* Invoke the body of a cwdr, assuming that the throw handler has | |
218 | already been set up. DATA points to a struct set up by cwdr that | |
816a6f06 JB |
219 | says what proc to call, and what args to apply it to. |
220 | ||
221 | With a little thought, we could replace this with scm_body_thunk, | |
222 | but I don't want to mess with that at the moment. */ | |
650fa1ab | 223 | static SCM |
39752bec | 224 | cwdr_body (void *data) |
650fa1ab JB |
225 | { |
226 | struct cwdr_body_data *c = (struct cwdr_body_data *) data; | |
227 | ||
228 | return scm_apply (c->body_proc, c->a1, c->args); | |
229 | } | |
230 | ||
e71575d9 MV |
231 | /* Record the fact that the body of the cwdr has thrown. Record |
232 | enough information to invoke the handler later when the dynamic | |
233 | root has been deestablished. */ | |
650fa1ab | 234 | |
f032b8a8 | 235 | static SCM |
e71575d9 | 236 | cwdr_handler (void *data, SCM tag, SCM args) |
f032b8a8 | 237 | { |
e71575d9 | 238 | struct cwdr_handler_data *c = (struct cwdr_handler_data *) data; |
f032b8a8 | 239 | |
e71575d9 MV |
240 | c->run_handler = 1; |
241 | c->tag = tag; | |
242 | c->args = args; | |
243 | return SCM_UNSPECIFIED; | |
f032b8a8 | 244 | } |
d564d753 MD |
245 | |
246 | /* This is the basic code for new root creation. | |
247 | * | |
248 | * WARNING! The order of actions in this routine is in many ways | |
249 | * critical. E. g., it is essential that an error doesn't leave Guile | |
650fa1ab | 250 | * in a messed up state. */ |
d564d753 | 251 | |
e71575d9 MV |
252 | SCM |
253 | scm_internal_cwdr (scm_catch_body_t body, void *body_data, | |
254 | scm_catch_handler_t handler, void *handler_data, | |
255 | SCM_STACKITEM *stack_start) | |
d564d753 | 256 | { |
e71575d9 MV |
257 | #ifdef USE_STACKJMPBUF |
258 | scm_contregs static_jmpbuf; | |
259 | #endif | |
d564d753 | 260 | int old_ints_disabled = scm_ints_disabled; |
8938d022 | 261 | SCM old_rootcont, old_winds; |
e71575d9 | 262 | struct cwdr_handler_data my_handler_data; |
d564d753 MD |
263 | SCM answer; |
264 | ||
e71575d9 | 265 | /* Create a fresh root continuation. */ |
d564d753 MD |
266 | { |
267 | SCM new_rootcont; | |
268 | SCM_NEWCELL (new_rootcont); | |
269 | SCM_REDEFER_INTS; | |
e71575d9 MV |
270 | #ifdef USE_STACKJMPBUF |
271 | SCM_SETJMPBUF (new_rootcont, &static_jmpbuf); | |
272 | #else | |
d564d753 | 273 | SCM_SETJMPBUF (new_rootcont, |
0db18cf4 | 274 | scm_must_malloc ((long) sizeof (scm_contregs), |
d564d753 | 275 | "inferior root continuation")); |
e71575d9 | 276 | #endif |
a6c64c3c | 277 | SCM_SETCAR (new_rootcont, scm_tc7_contin); |
d564d753 MD |
278 | SCM_DYNENV (new_rootcont) = SCM_EOL; |
279 | SCM_BASE (new_rootcont) = stack_start; | |
8938d022 | 280 | SCM_SEQ (new_rootcont) = ++n_dynamic_roots; |
d564d753 MD |
281 | #ifdef DEBUG_EXTENSIONS |
282 | SCM_DFRAME (new_rootcont) = 0; | |
283 | #endif | |
8938d022 MD |
284 | old_rootcont = scm_rootcont; |
285 | scm_rootcont = new_rootcont; | |
d564d753 MD |
286 | SCM_REALLOW_INTS; |
287 | } | |
288 | ||
8938d022 MD |
289 | /* Exit caller's dynamic state. |
290 | */ | |
291 | old_winds = scm_dynwinds; | |
292 | scm_dowinds (SCM_EOL, scm_ilength (scm_dynwinds)); | |
d564d753 | 293 | #ifdef DEBUG_EXTENSIONS |
308277cb | 294 | SCM_DFRAME (old_rootcont) = scm_last_debug_frame; |
8938d022 | 295 | scm_last_debug_frame = 0; |
d564d753 | 296 | #endif |
650fa1ab | 297 | |
e71575d9 MV |
298 | { |
299 | my_handler_data.run_handler = 0; | |
816a6f06 | 300 | answer = scm_internal_catch (SCM_BOOL_T, |
e71575d9 MV |
301 | body, body_data, |
302 | cwdr_handler, &my_handler_data); | |
650fa1ab | 303 | } |
e71575d9 | 304 | |
d564d753 MD |
305 | scm_dowinds (old_winds, - scm_ilength (old_winds)); |
306 | SCM_REDEFER_INTS; | |
e71575d9 MV |
307 | #ifdef USE_STACKCJMPBUF |
308 | SCM_SETJMPBUF (scm_rootcont, NULL); | |
309 | #endif | |
d564d753 | 310 | #ifdef DEBUG_EXTENSIONS |
308277cb | 311 | scm_last_debug_frame = SCM_DFRAME (old_rootcont); |
d564d753 | 312 | #endif |
308277cb | 313 | scm_rootcont = old_rootcont; |
d564d753 MD |
314 | SCM_REALLOW_INTS; |
315 | scm_ints_disabled = old_ints_disabled; | |
e71575d9 MV |
316 | |
317 | /* Now run the real handler iff the body did a throw. */ | |
318 | if (my_handler_data.run_handler) | |
319 | return handler (handler_data, my_handler_data.tag, my_handler_data.args); | |
320 | else | |
321 | return answer; | |
d564d753 MD |
322 | } |
323 | ||
e71575d9 MV |
324 | /* The original CWDR for invoking Scheme code with a Scheme handler. */ |
325 | ||
326 | static SCM | |
327 | cwdr (SCM proc, SCM a1, SCM args, SCM handler, SCM_STACKITEM *stack_start) | |
328 | { | |
329 | struct cwdr_body_data c; | |
330 | ||
331 | c.a1 = a1; | |
332 | c.args = args; | |
333 | c.body_proc = proc; | |
334 | ||
335 | return scm_internal_cwdr (cwdr_body, &c, | |
336 | scm_handle_by_proc, &handler, | |
337 | stack_start); | |
338 | } | |
d564d753 | 339 | |
8938d022 | 340 | SCM_PROC(s_call_with_dynamic_root, "call-with-dynamic-root", 2, 0, 0, scm_call_with_dynamic_root); |
d564d753 | 341 | SCM |
8938d022 | 342 | scm_call_with_dynamic_root (thunk, handler) |
d564d753 MD |
343 | SCM thunk; |
344 | SCM handler; | |
d564d753 MD |
345 | { |
346 | SCM_STACKITEM stack_place; | |
347 | ||
8938d022 | 348 | return cwdr (thunk, SCM_EOL, SCM_EOL, handler, &stack_place); |
d564d753 MD |
349 | } |
350 | ||
351 | SCM_PROC(s_dynamic_root, "dynamic-root", 0, 0, 0, scm_dynamic_root); | |
d564d753 MD |
352 | SCM |
353 | scm_dynamic_root () | |
d564d753 MD |
354 | { |
355 | return scm_ulong2num (SCM_SEQ (scm_root->rootcont)); | |
356 | } | |
357 | ||
d564d753 | 358 | SCM |
8938d022 | 359 | scm_apply_with_dynamic_root (proc, a1, args, handler) |
d564d753 MD |
360 | SCM proc; |
361 | SCM a1; | |
362 | SCM args; | |
1cc91f1b | 363 | SCM handler; |
d564d753 MD |
364 | { |
365 | SCM_STACKITEM stack_place; | |
8938d022 | 366 | return cwdr (proc, a1, args, handler, &stack_place); |
d564d753 | 367 | } |
0f2d19dd JB |
368 | |
369 | \f | |
370 | ||
371 | /* Call thunk(closure) underneath a top-level error handler. | |
372 | * If an error occurs, pass the exitval through err_filter and return it. | |
373 | * If no error occurs, return the value of thunk. | |
374 | */ | |
375 | ||
376 | ||
377 | #ifdef _UNICOS | |
378 | typedef int setjmp_type; | |
379 | #else | |
380 | typedef long setjmp_type; | |
381 | #endif | |
382 | ||
383 | ||
1cc91f1b | 384 | |
0f2d19dd JB |
385 | SCM |
386 | scm_call_catching_errors (thunk, err_filter, closure) | |
387 | SCM (*thunk)(); | |
388 | SCM (*err_filter)(); | |
d564d753 | 389 | void *closure; |
0f2d19dd JB |
390 | { |
391 | SCM answer; | |
392 | setjmp_type i; | |
faa6b3df | 393 | #ifdef DEBUG_EXTENSIONS |
8938d022 | 394 | SCM_DFRAME (scm_rootcont) = scm_last_debug_frame; |
faa6b3df | 395 | #endif |
0f2d19dd | 396 | i = setjmp (SCM_JMPBUF (scm_rootcont)); |
faa6b3df | 397 | scm_stack_checking_enabled_p = SCM_STACK_CHECKING_P; |
0f2d19dd JB |
398 | if (!i) |
399 | { | |
400 | scm_gc_heap_lock = 0; | |
401 | answer = thunk (closure); | |
402 | } | |
403 | else | |
404 | { | |
405 | scm_gc_heap_lock = 1; | |
406 | answer = err_filter (scm_exitval, closure); | |
407 | } | |
408 | return answer; | |
409 | } | |
410 | ||
d564d753 MD |
411 | void |
412 | scm_init_root () | |
413 | { | |
414 | scm_tc16_root = scm_newsmob (&root_smob); | |
415 | #include "root.x" | |
416 | } |