Commit | Line | Data |
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86a597f8 | 1 | /* Copyright (C) 1995,1996,1997,1998,2000,2001, 2003, 2004, 2006, 2008 Free Software Foundation, Inc. |
0f2d19dd | 2 | * |
73be1d9e MV |
3 | * This library is free software; you can redistribute it and/or |
4 | * modify it under the terms of the GNU Lesser General Public | |
5 | * License as published by the Free Software Foundation; either | |
6 | * version 2.1 of the License, or (at your option) any later version. | |
0f2d19dd | 7 | * |
73be1d9e MV |
8 | * This library 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 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 | |
92205699 | 15 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
73be1d9e | 16 | */ |
1bbd0b84 | 17 | |
1bbd0b84 | 18 | |
0f2d19dd | 19 | \f |
dbb605f5 LC |
20 | #ifdef HAVE_CONFIG_H |
21 | # include <config.h> | |
22 | #endif | |
0f2d19dd JB |
23 | |
24 | #include <stdio.h> | |
a0599745 | 25 | #include "libguile/_scm.h" |
54f2445b | 26 | #include "libguile/async.h" |
a0599745 MD |
27 | #include "libguile/smob.h" |
28 | #include "libguile/alist.h" | |
29 | #include "libguile/eval.h" | |
30 | #include "libguile/eq.h" | |
31 | #include "libguile/dynwind.h" | |
32 | #include "libguile/backtrace.h" | |
a0599745 | 33 | #include "libguile/debug.h" |
a0599745 MD |
34 | #include "libguile/continuations.h" |
35 | #include "libguile/stackchk.h" | |
36 | #include "libguile/stacks.h" | |
37 | #include "libguile/fluids.h" | |
38 | #include "libguile/ports.h" | |
c96d76b8 | 39 | #include "libguile/lang.h" |
a0599745 MD |
40 | #include "libguile/validate.h" |
41 | #include "libguile/throw.h" | |
9de87eea | 42 | #include "libguile/init.h" |
a2c40dc7 | 43 | #include "libguile/strings.h" |
747a1635 | 44 | #include "libguile/vm.h" |
0f2d19dd | 45 | |
22fc179a HWN |
46 | #include "libguile/private-options.h" |
47 | ||
48 | ||
32f7b3a1 | 49 | \f |
74229f75 | 50 | /* the jump buffer data structure */ |
92c2555f | 51 | static scm_t_bits tc16_jmpbuffer; |
0f2d19dd | 52 | |
e841c3e0 | 53 | #define SCM_JMPBUFP(OBJ) SCM_TYP16_PREDICATE (tc16_jmpbuffer, OBJ) |
c209c88e | 54 | |
e841c3e0 | 55 | #define JBACTIVE(OBJ) (SCM_CELL_WORD_0 (OBJ) & (1L << 16L)) |
22a52da1 DH |
56 | #define ACTIVATEJB(x) \ |
57 | (SCM_SET_CELL_WORD_0 ((x), (SCM_CELL_WORD_0 (x) | (1L << 16L)))) | |
58 | #define DEACTIVATEJB(x) \ | |
59 | (SCM_SET_CELL_WORD_0 ((x), (SCM_CELL_WORD_0 (x) & ~(1L << 16L)))) | |
0f2d19dd | 60 | |
4260a7fc | 61 | #define JBJMPBUF(OBJ) ((jmp_buf *) SCM_CELL_WORD_1 (OBJ)) |
770e048f | 62 | #define SETJBJMPBUF(x, v) (SCM_SET_CELL_WORD_1 ((x), (scm_t_bits) (v))) |
92c2555f | 63 | #define SCM_JBDFRAME(x) ((scm_t_debug_frame *) SCM_CELL_WORD_2 (x)) |
770e048f | 64 | #define SCM_SETJBDFRAME(x, v) (SCM_SET_CELL_WORD_2 ((x), (scm_t_bits) (v))) |
43e01b1e NJ |
65 | #define SCM_JBPREUNWIND(x) ((struct pre_unwind_data *) SCM_CELL_WORD_3 (x)) |
66 | #define SCM_SETJBPREUNWIND(x, v) (SCM_SET_CELL_WORD_3 ((x), (scm_t_bits) (v))) | |
0f2d19dd | 67 | |
0f2d19dd | 68 | static int |
e81d98ec | 69 | jmpbuffer_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED) |
0f2d19dd | 70 | { |
b7f3516f TT |
71 | scm_puts ("#<jmpbuffer ", port); |
72 | scm_puts (JBACTIVE(exp) ? "(active) " : "(inactive) ", port); | |
0345e278 | 73 | scm_uintprint((scm_t_bits) JBJMPBUF (exp), 16, port); |
b7f3516f | 74 | scm_putc ('>', port); |
0f2d19dd JB |
75 | return 1 ; |
76 | } | |
77 | ||
0f2d19dd | 78 | static SCM |
1bbd0b84 | 79 | make_jmpbuf (void) |
0f2d19dd JB |
80 | { |
81 | SCM answer; | |
86a597f8 NJ |
82 | SCM_NEWSMOB2 (answer, tc16_jmpbuffer, 0, 0); |
83 | SETJBJMPBUF(answer, (jmp_buf *)0); | |
84 | DEACTIVATEJB(answer); | |
0f2d19dd JB |
85 | return answer; |
86 | } | |
87 | ||
74229f75 | 88 | \f |
43e01b1e | 89 | /* scm_c_catch (the guts of catch) */ |
74229f75 | 90 | |
0f2d19dd JB |
91 | struct jmp_buf_and_retval /* use only on the stack, in scm_catch */ |
92 | { | |
93 | jmp_buf buf; /* must be first */ | |
94 | SCM throw_tag; | |
95 | SCM retval; | |
96 | }; | |
97 | ||
43e01b1e NJ |
98 | /* These are the structures we use to store pre-unwind handling (aka |
99 | "lazy") information for a regular catch, and put on the wind list | |
100 | for a "lazy" catch. They store the pre-unwind handler function to | |
101 | call, and the data pointer to pass through to it. It's not a | |
102 | Scheme closure, but it is a function with data, so the term | |
103 | "closure" is appropriate in its broader sense. | |
650fa1ab | 104 | |
43e01b1e NJ |
105 | (We don't need anything like this to run the normal (post-unwind) |
106 | catch handler, because the same C frame runs both the body and the | |
107 | handler.) */ | |
108 | ||
109 | struct pre_unwind_data { | |
110 | scm_t_catch_handler handler; | |
111 | void *handler_data; | |
112 | int running; | |
113 | int lazy_catch_p; | |
114 | }; | |
115 | ||
116 | ||
117 | /* scm_c_catch is the guts of catch. It handles all the mechanics of | |
118 | setting up a catch target, invoking the catch body, and perhaps | |
119 | invoking the handler if the body does a throw. | |
650fa1ab JB |
120 | |
121 | The function is designed to be usable from C code, but is general | |
122 | enough to implement all the semantics Guile Scheme expects from | |
123 | throw. | |
124 | ||
125 | TAG is the catch tag. Typically, this is a symbol, but this | |
126 | function doesn't actually care about that. | |
127 | ||
128 | BODY is a pointer to a C function which runs the body of the catch; | |
129 | this is the code you can throw from. We call it like this: | |
19b27fa2 | 130 | BODY (BODY_DATA) |
650fa1ab | 131 | where: |
816a6f06 JB |
132 | BODY_DATA is just the BODY_DATA argument we received; we pass it |
133 | through to BODY as its first argument. The caller can make | |
134 | BODY_DATA point to anything useful that BODY might need. | |
650fa1ab JB |
135 | |
136 | HANDLER is a pointer to a C function to deal with a throw to TAG, | |
137 | should one occur. We call it like this: | |
86327304 | 138 | HANDLER (HANDLER_DATA, THROWN_TAG, THROW_ARGS) |
650fa1ab | 139 | where |
816a6f06 JB |
140 | HANDLER_DATA is the HANDLER_DATA argument we recevied; it's the |
141 | same idea as BODY_DATA above. | |
86327304 JB |
142 | THROWN_TAG is the tag that the user threw to; usually this is |
143 | TAG, but it could be something else if TAG was #t (i.e., a | |
144 | catch-all), or the user threw to a jmpbuf. | |
650fa1ab | 145 | THROW_ARGS is the list of arguments the user passed to the THROW |
4dd8323f | 146 | function, after the tag. |
650fa1ab | 147 | |
3eed3475 JB |
148 | BODY_DATA is just a pointer we pass through to BODY. HANDLER_DATA |
149 | is just a pointer we pass through to HANDLER. We don't actually | |
150 | use either of those pointers otherwise ourselves. The idea is | |
151 | that, if our caller wants to communicate something to BODY or | |
152 | HANDLER, it can pass a pointer to it as MUMBLE_DATA, which BODY and | |
153 | HANDLER can then use. Think of it as a way to make BODY and | |
154 | HANDLER closures, not just functions; MUMBLE_DATA points to the | |
155 | enclosed variables. | |
156 | ||
157 | Of course, it's up to the caller to make sure that any data a | |
158 | MUMBLE_DATA needs is protected from GC. A common way to do this is | |
159 | to make MUMBLE_DATA a pointer to data stored in an automatic | |
160 | structure variable; since the collector must scan the stack for | |
161 | references anyway, this assures that any references in MUMBLE_DATA | |
162 | will be found. */ | |
650fa1ab | 163 | |
0f2d19dd | 164 | SCM |
43e01b1e NJ |
165 | scm_c_catch (SCM tag, |
166 | scm_t_catch_body body, void *body_data, | |
167 | scm_t_catch_handler handler, void *handler_data, | |
168 | scm_t_catch_handler pre_unwind_handler, void *pre_unwind_handler_data) | |
0f2d19dd JB |
169 | { |
170 | struct jmp_buf_and_retval jbr; | |
171 | SCM jmpbuf; | |
172 | SCM answer; | |
747a1635 AW |
173 | SCM vm; |
174 | SCM *sp = NULL, *fp = NULL; /* to reset the vm */ | |
43e01b1e | 175 | struct pre_unwind_data pre_unwind; |
0f2d19dd | 176 | |
747a1635 AW |
177 | vm = scm_the_vm (); |
178 | if (SCM_NFALSEP (vm)) | |
179 | { | |
180 | sp = SCM_VM_DATA (vm)->sp; | |
181 | fp = SCM_VM_DATA (vm)->fp; | |
182 | } | |
183 | ||
11702758 | 184 | jmpbuf = make_jmpbuf (); |
0f2d19dd | 185 | answer = SCM_EOL; |
9de87eea | 186 | scm_i_set_dynwinds (scm_acons (tag, jmpbuf, scm_i_dynwinds ())); |
0f2d19dd | 187 | SETJBJMPBUF(jmpbuf, &jbr.buf); |
9de87eea | 188 | SCM_SETJBDFRAME(jmpbuf, scm_i_last_debug_frame ()); |
43e01b1e NJ |
189 | |
190 | pre_unwind.handler = pre_unwind_handler; | |
191 | pre_unwind.handler_data = pre_unwind_handler_data; | |
192 | pre_unwind.running = 0; | |
193 | pre_unwind.lazy_catch_p = 0; | |
194 | SCM_SETJBPREUNWIND(jmpbuf, &pre_unwind); | |
195 | ||
0f2d19dd JB |
196 | if (setjmp (jbr.buf)) |
197 | { | |
198 | SCM throw_tag; | |
199 | SCM throw_args; | |
200 | ||
7f759d79 MD |
201 | #ifdef STACK_CHECKING |
202 | scm_stack_checking_enabled_p = SCM_STACK_CHECKING_P; | |
203 | #endif | |
9de87eea | 204 | SCM_CRITICAL_SECTION_START; |
0f2d19dd | 205 | DEACTIVATEJB (jmpbuf); |
9de87eea MV |
206 | scm_i_set_dynwinds (SCM_CDR (scm_i_dynwinds ())); |
207 | SCM_CRITICAL_SECTION_END; | |
0f2d19dd JB |
208 | throw_args = jbr.retval; |
209 | throw_tag = jbr.throw_tag; | |
210 | jbr.throw_tag = SCM_EOL; | |
211 | jbr.retval = SCM_EOL; | |
747a1635 AW |
212 | if (SCM_NFALSEP (vm)) |
213 | { | |
214 | SCM_VM_DATA (vm)->sp = sp; | |
215 | SCM_VM_DATA (vm)->fp = fp; | |
216 | #ifdef VM_ENABLE_STACK_NULLING | |
217 | /* see vm.c -- you'll have to enable this manually */ | |
218 | memset (sp + 1, 0, | |
219 | (SCM_VM_DATA (vm)->stack_size | |
220 | - (sp + 1 - SCM_VM_DATA (vm)->stack_base)) * sizeof(SCM)); | |
221 | #endif | |
222 | } | |
223 | else if (SCM_NFALSEP ((vm = scm_the_vm ()))) | |
224 | { | |
225 | /* oof, it's possible this catch was called before the vm was | |
226 | booted... yick. anyway, try to reset the vm stack. */ | |
227 | SCM_VM_DATA (vm)->sp = SCM_VM_DATA (vm)->stack_base - 1; | |
228 | SCM_VM_DATA (vm)->fp = NULL; | |
229 | #ifdef VM_ENABLE_STACK_NULLING | |
230 | /* see vm.c -- you'll have to enable this manually */ | |
231 | memset (SCM_VM_DATA (vm)->stack_base, 0, | |
232 | SCM_VM_DATA (vm)->stack_size * sizeof(SCM)); | |
233 | #endif | |
234 | } | |
235 | ||
816a6f06 | 236 | answer = handler (handler_data, throw_tag, throw_args); |
0f2d19dd JB |
237 | } |
238 | else | |
239 | { | |
240 | ACTIVATEJB (jmpbuf); | |
492960a4 | 241 | answer = body (body_data); |
9de87eea | 242 | SCM_CRITICAL_SECTION_START; |
0f2d19dd | 243 | DEACTIVATEJB (jmpbuf); |
9de87eea MV |
244 | scm_i_set_dynwinds (SCM_CDR (scm_i_dynwinds ())); |
245 | SCM_CRITICAL_SECTION_END; | |
0f2d19dd JB |
246 | } |
247 | return answer; | |
248 | } | |
249 | ||
43e01b1e NJ |
250 | SCM |
251 | scm_internal_catch (SCM tag, | |
252 | scm_t_catch_body body, void *body_data, | |
253 | scm_t_catch_handler handler, void *handler_data) | |
254 | { | |
255 | return scm_c_catch(tag, | |
256 | body, body_data, | |
257 | handler, handler_data, | |
258 | NULL, NULL); | |
259 | } | |
650fa1ab | 260 | |
18eadcbe | 261 | |
43e01b1e NJ |
262 | \f |
263 | /* The smob tag for pre_unwind_data smobs. */ | |
264 | static scm_t_bits tc16_pre_unwind_data; | |
18eadcbe JB |
265 | |
266 | /* Strictly speaking, we could just pass a zero for our print | |
267 | function, because we don't need to print them. They should never | |
268 | appear in normal data structures, only in the wind list. However, | |
269 | it might be nice for debugging someday... */ | |
270 | static int | |
43e01b1e | 271 | pre_unwind_data_print (SCM closure, SCM port, scm_print_state *pstate SCM_UNUSED) |
18eadcbe | 272 | { |
43e01b1e | 273 | struct pre_unwind_data *c = (struct pre_unwind_data *) SCM_CELL_WORD_1 (closure); |
18eadcbe JB |
274 | char buf[200]; |
275 | ||
43e01b1e | 276 | sprintf (buf, "#<pre-unwind-data 0x%lx 0x%lx>", |
18eadcbe | 277 | (long) c->handler, (long) c->handler_data); |
b7f3516f | 278 | scm_puts (buf, port); |
18eadcbe JB |
279 | |
280 | return 1; | |
281 | } | |
282 | ||
18eadcbe | 283 | |
43e01b1e | 284 | /* Given a pointer to a pre_unwind_data structure, return a smob for it, |
18eadcbe JB |
285 |