Commit | Line | Data |
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d69531e2 | 1 | /* Copyright (C) 1995,1996,1998,1999,2000,2001, 2003, 2004, 2006, 2008, 2010 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 JB |
20 | \f |
21 | ||
dbb605f5 LC |
22 | #ifdef HAVE_CONFIG_H |
23 | # include <config.h> | |
24 | #endif | |
25 | ||
4845bbae MV |
26 | #include <assert.h> |
27 | ||
a0599745 MD |
28 | #include "libguile/_scm.h" |
29 | #include "libguile/eval.h" | |
30 | #include "libguile/alist.h" | |
31 | #include "libguile/fluids.h" | |
32 | #include "libguile/ports.h" | |
33 | #include "libguile/smob.h" | |
0f2d19dd | 34 | |
a0599745 | 35 | #include "libguile/dynwind.h" |
0f2d19dd JB |
36 | \f |
37 | ||
38 | /* {Dynamic wind} | |
b3460a50 MV |
39 | |
40 | Things that can be on the wind list: | |
41 | ||
4845bbae MV |
42 | #<frame> |
43 | #<winder> | |
b3460a50 MV |
44 | (enter-proc . leave-proc) dynamic-wind |
45 | (tag . jmpbuf) catch | |
43e01b1e | 46 | (tag . pre-unwind-data) throw-handler / lazy-catch |
b3460a50 MV |
47 | tag is either a symbol or a boolean |
48 | ||
b3460a50 | 49 | */ |
0f2d19dd JB |
50 | |
51 | ||
52 | ||
d69531e2 AW |
53 | SCM |
54 | scm_dynamic_wind (SCM in_guard, SCM thunk, SCM out_guard) | |
55 | #define FUNC_NAME "dynamic-wind" | |
0f2d19dd | 56 | { |
9de87eea | 57 | SCM ans, old_winds; |
7888309b | 58 | SCM_ASSERT (scm_is_true (scm_thunk_p (out_guard)), |
1e6808ea | 59 | out_guard, |
1bbd0b84 | 60 | SCM_ARG3, FUNC_NAME); |
fdc28395 | 61 | scm_call_0 (in_guard); |
9de87eea MV |
62 | old_winds = scm_i_dynwinds (); |
63 | scm_i_set_dynwinds (scm_acons (in_guard, out_guard, old_winds)); | |
fdc28395 | 64 | ans = scm_call_0 (thunk); |
9de87eea | 65 | scm_i_set_dynwinds (old_winds); |
fdc28395 | 66 | scm_call_0 (out_guard); |
0f2d19dd JB |
67 | return ans; |
68 | } | |
1bbd0b84 | 69 | #undef FUNC_NAME |
0f2d19dd | 70 | |
3346a90f | 71 | SCM |
92c2555f MV |
72 | scm_internal_dynamic_wind (scm_t_guard before, |
73 | scm_t_inner inner, | |
74 | scm_t_guard after, | |
3346a90f MD |
75 | void *inner_data, |
76 | void *guard_data) | |
77 | { | |
4845bbae MV |
78 | SCM ans; |
79 | ||
661ae7ab MV |
80 | scm_dynwind_begin (SCM_F_DYNWIND_REWINDABLE); |
81 | scm_dynwind_rewind_handler (before, guard_data, SCM_F_WIND_EXPLICITLY); | |
82 | scm_dynwind_unwind_handler (after, guard_data, SCM_F_WIND_EXPLICITLY); | |
3346a90f | 83 | ans = inner (inner_data); |
661ae7ab | 84 | scm_dynwind_end (); |
3346a90f MD |
85 | return ans; |
86 | } | |
1cc91f1b | 87 | |
4845bbae MV |
88 | /* Frames and winders. */ |
89 | ||
90 | static scm_t_bits tc16_frame; | |
91 | #define FRAME_P(f) SCM_SMOB_PREDICATE (tc16_frame, (f)) | |
92 | ||
f5710d53 MV |
93 | #define FRAME_F_REWINDABLE (1 << 0) |
94 | #define FRAME_REWINDABLE_P(f) (SCM_SMOB_FLAGS(f) & FRAME_F_REWINDABLE) | |
4845bbae MV |
95 | |
96 | static scm_t_bits tc16_winder; | |
14578fa4 | 97 | #define WINDER_P(w) SCM_SMOB_PREDICATE (tc16_winder, (w)) |
f5710d53 MV |
98 | #define WINDER_PROC(w) ((void (*)(void *))SCM_SMOB_DATA (w)) |
99 | #define WINDER_DATA(w) ((void *)SCM_SMOB_DATA_2 (w)) | |
4845bbae | 100 | |
f5710d53 MV |
101 | #define WINDER_F_EXPLICIT (1 << 0) |
102 | #define WINDER_F_REWIND (1 << 1) | |
103 | #define WINDER_F_MARK (1 << 2) | |
104 | #define WINDER_EXPLICIT_P(w) (SCM_SMOB_FLAGS(w) & WINDER_F_EXPLICIT) | |
105 | #define WINDER_REWIND_P(w) (SCM_SMOB_FLAGS(w) & WINDER_F_REWIND) | |
106 | #define WINDER_MARK_P(w) (SCM_SMOB_FLAGS(w) & WINDER_F_MARK) | |
4845bbae MV |
107 | |
108 | void | |
98241dc5 | 109 | scm_dynwind_begin (scm_t_dynwind_flags flags) |
4845bbae MV |
110 | { |
111 | SCM f; | |
f5710d53 | 112 | SCM_NEWSMOB (f, tc16_frame, 0); |
661ae7ab | 113 | if (flags & SCM_F_DYNWIND_REWINDABLE) |
f5710d53 | 114 | SCM_SET_SMOB_FLAGS (f, FRAME_F_REWINDABLE); |
9de87eea | 115 | scm_i_set_dynwinds (scm_cons (f, scm_i_dynwinds ())); |
4845bbae MV |
116 | } |
117 | ||
118 | void | |
661ae7ab | 119 | scm_dynwind_end (void) |
4845bbae | 120 | { |
9de87eea MV |
121 | SCM winds; |
122 | ||
0888de4f MV |
123 | /* Unwind upto and including the next frame entry. We can only |
124 | encounter #<winder> entries on the way. | |
4845bbae MV |
125 | */ |
126 | ||
9de87eea MV |
127 | winds = scm_i_dynwinds (); |
128 | while (scm_is_pair (winds)) | |
4845bbae | 129 | { |
9de87eea MV |
130 | SCM entry = SCM_CAR (winds); |
131 | winds = SCM_CDR (winds); | |
132 | ||
133 | scm_i_set_dynwinds (winds); | |
0888de4f MV |
134 | |
135 | if (FRAME_P (entry)) | |
136 | return; | |
137 | ||
138 | assert (WINDER_P (entry)); | |
139 | if (!WINDER_REWIND_P (entry) && WINDER_EXPLICIT_P (entry)) | |
140 | WINDER_PROC(entry) (WINDER_DATA (entry)); | |
4845bbae MV |
141 | } |
142 | ||
143 | assert (0); | |
144 | } | |
145 | ||
146 | void | |
98241dc5 NJ |
147 | scm_dynwind_unwind_handler (void (*proc) (void *), void *data, |
148 | scm_t_wind_flags flags) | |
4845bbae MV |
149 | { |
150 | SCM w; | |
f5710d53 MV |
151 | SCM_NEWSMOB2 (w, tc16_winder, (scm_t_bits) proc, (scm_t_bits) data); |
152 | if (flags & SCM_F_WIND_EXPLICITLY) | |
153 | SCM_SET_SMOB_FLAGS (w, WINDER_F_EXPLICIT); | |
9de87eea | 154 | scm_i_set_dynwinds (scm_cons (w, scm_i_dynwinds ())); |
4845bbae MV |
155 | } |
156 | ||
157 | void | |
98241dc5 NJ |
158 | scm_dynwind_rewind_handler (void (*proc) (void *), void *data, |
159 | scm_t_wind_flags flags) | |
4845bbae MV |
160 | { |
161 | SCM w; | |
f5710d53 MV |
162 | SCM_NEWSMOB2 (w, tc16_winder, (scm_t_bits) proc, (scm_t_bits) data); |
163 | SCM_SET_SMOB_FLAGS (w, WINDER_F_REWIND); | |
9de87eea | 164 | scm_i_set_dynwinds (scm_cons (w, scm_i_dynwinds ())); |
a520e4f0 MV |
165 | if (flags & SCM_F_WIND_EXPLICITLY) |
166 | proc (data); | |
167 | } | |
168 | ||
169 | void | |
98241dc5 NJ |
170 | scm_dynwind_unwind_handler_with_scm (void (*proc) (SCM), SCM data, |
171 | scm_t_wind_flags flags) | |
a520e4f0 MV |
172 | { |
173 | SCM w; | |
174 | scm_t_bits fl = ((flags&SCM_F_WIND_EXPLICITLY)? WINDER_F_EXPLICIT : 0); | |
f5710d53 MV |
175 | SCM_NEWSMOB2 (w, tc16_winder, (scm_t_bits) proc, SCM_UNPACK (data)); |
176 | SCM_SET_SMOB_FLAGS (w, fl | WINDER_F_MARK); | |
9de87eea | 177 | scm_i_set_dynwinds (scm_cons (w, scm_i_dynwinds ())); |
a520e4f0 MV |
178 | } |
179 | ||
180 | void | |
98241dc5 NJ |
181 | scm_dynwind_rewind_handler_with_scm (void (*proc) (SCM), SCM data, |
182 | scm_t_wind_flags flags) | |
a520e4f0 MV |
183 | { |
184 | SCM w; | |
f5710d53 MV |
185 | SCM_NEWSMOB2 (w, tc16_winder, (scm_t_bits) proc, SCM_UNPACK (data)); |
186 | SCM_SET_SMOB_FLAGS (w, WINDER_F_REWIND | WINDER_F_MARK); | |
9de87eea | 187 | scm_i_set_dynwinds (scm_cons (w, scm_i_dynwinds ())); |
a520e4f0 | 188 | if (flags & SCM_F_WIND_EXPLICITLY) |
4845bbae MV |
189 | proc (data); |
190 | } | |
191 | ||
6d5649b7 | 192 | void |
661ae7ab | 193 | scm_dynwind_free (void *mem) |
6d5649b7 | 194 | { |
661ae7ab | 195 | scm_dynwind_unwind_handler (free, mem, SCM_F_WIND_EXPLICITLY); |
6d5649b7 MV |
196 | } |
197 | ||
c2654ef0 | 198 | #ifdef GUILE_DEBUG |
a1ec6916 | 199 | SCM_DEFINE (scm_wind_chain, "wind-chain", 0, 0, 0, |
1bbd0b84 | 200 | (), |
156149ad MG |
201 | "Return the current wind chain. The wind chain contains all\n" |
202 | "information required by @code{dynamic-wind} to call its\n" | |
203 | "argument thunks when entering/exiting its scope.") | |
1bbd0b84 | 204 | #define FUNC_NAME s_scm_wind_chain |
c2654ef0 | 205 | { |
9de87eea | 206 | return scm_i_dynwinds (); |
c2654ef0 | 207 | } |
1bbd0b84 | 208 | #undef FUNC_NAME |
c2654ef0 MD |
209 | #endif |
210 | ||
2e171178 | 211 | void |
904a077d | 212 | scm_swap_bindings (SCM vars, SCM vals) |
6778caf9 MD |
213 | { |
214 | SCM tmp; | |
215 | while (SCM_NIMP (vals)) | |
216 | { | |
904a077d MV |
217 | tmp = SCM_VARIABLE_REF (SCM_CAR (vars)); |
218 | SCM_VARIABLE_SET (SCM_CAR (vars), SCM_CAR (vals)); | |
6778caf9 | 219 | SCM_SETCAR (vals, tmp); |
904a077d | 220 | vars = SCM_CDR (vars); |
6778caf9 MD |
221 | vals = SCM_CDR (vals); |
222 | } | |
223 | } | |
c2654ef0 | 224 | |
4845bbae | 225 | void |
c014a02e | 226 | scm_dowinds (SCM to, long delta) |
4845bbae | 227 | { |
14578fa4 | 228 | scm_i_dowinds (to, delta, NULL, NULL); |
4845bbae MV |
229 | } |
230 | ||
231 | void | |
14578fa4 | 232 | scm_i_dowinds (SCM to, long delta, void (*turn_func) (void *), void *data) |
0f2d19dd JB |
233 | { |
234 | tail: | |
9de87eea | 235 | if (scm_is_eq (to, scm_i_dynwinds ())) |
4845bbae MV |
236 | { |
237 | if (turn_func) | |
238 | turn_func (data); | |
239 | } | |
1be6b49c | 240 | else if (delta < 0) |
0f2d19dd JB |
241 | { |
242 | SCM wind_elt; | |
243 | SCM wind_key; | |
244 | ||
14578fa4 | 245 | scm_i_dowinds (SCM_CDR (to), 1 + delta, turn_func, data); |
0f2d19dd | 246 | wind_elt = SCM_CAR (to); |
4845bbae | 247 | |
928e0f42 | 248 | if (FRAME_P (wind_elt)) |
0f2d19dd | 249 | { |
928e0f42 MV |
250 | if (!FRAME_REWINDABLE_P (wind_elt)) |
251 | scm_misc_error ("dowinds", | |
252 | "cannot invoke continuation from this context", | |
253 | SCM_EOL); | |
254 | } | |
255 | else if (WINDER_P (wind_elt)) | |
256 | { | |
257 | if (WINDER_REWIND_P (wind_elt)) | |
258 | WINDER_PROC (wind_elt) (WINDER_DATA (wind_elt)); | |
0f2d19dd JB |
259 | } |
260 | else | |
0f2d19dd | 261 | { |
928e0f42 MV |
262 | wind_key = SCM_CAR (wind_elt); |
263 | /* key = #t | symbol | thunk | list of variables */ | |
264 | if (SCM_NIMP (wind_key)) | |
4845bbae | 265 | { |
d2e53ed6 | 266 | if (scm_is_pair (wind_key)) |
4845bbae | 267 | { |
928e0f42 MV |
268 | if (SCM_VARIABLEP (SCM_CAR (wind_key))) |
269 | scm_swap_bindings (wind_key, SCM_CDR (wind_elt)); | |
904a077d | 270 | } |
5a963489 | 271 | else if (scm_is_true (scm_thunk_p (wind_key))) |
928e0f42 | 272 | scm_call_0 (wind_key); |
b3460a50 | 273 | } |
0f2d19dd | 274 | } |
928e0f42 | 275 | |
9de87eea | 276 | scm_i_set_dynwinds (to); |
0f2d19dd JB |
277 | } |
278 | else | |
279 | { | |
9de87eea | 280 | SCM wind; |
0f2d19dd JB |
281 | SCM wind_elt; |
282 | SCM wind_key; | |
283 | ||
9de87eea MV |
284 | wind = scm_i_dynwinds (); |
285 | wind_elt = SCM_CAR (wind); | |
286 | scm_i_set_dynwinds (SCM_CDR (wind)); | |
4845bbae | 287 | |
928e0f42 | 288 | if (FRAME_P (wind_elt)) |
0f2d19dd | 289 | { |
928e0f42 MV |
290 | /* Nothing to do. */ |
291 | } | |
292 | else if (WINDER_P (wind_elt)) | |
293 | { | |
294 | if (!WINDER_REWIND_P (wind_elt)) | |
295 | WINDER_PROC (wind_elt) (WINDER_DATA (wind_elt)); | |
0f2d19dd JB |
296 | } |
297 | else | |
0f2d19dd | 298 | { |
928e0f42 MV |
299 | wind_key = SCM_CAR (wind_elt); |
300 | if (SCM_NIMP (wind_key)) | |
4845bbae | 301 | { |
d2e53ed6 | 302 | if (scm_is_pair (wind_key)) |
4845bbae | 303 | { |
928e0f42 MV |
304 | if (SCM_VARIABLEP (SCM_CAR (wind_key))) |
305 | scm_swap_bindings (wind_key, SCM_CDR (wind_elt)); | |
904a077d | 306 | } |
5a963489 | 307 | else if (scm_is_true (scm_thunk_p (wind_key))) |
928e0f42 | 308 | scm_call_0 (SCM_CDR (wind_elt)); |
b3460a50 | 309 | } |
0f2d19dd | 310 | } |
928e0f42 | 311 | |
0f2d19dd JB |
312 | delta--; |
313 | goto tail; /* scm_dowinds(to, delta-1); */ | |
314 | } | |
315 | } | |
316 | ||
0f2d19dd JB |
317 | void |
318 | scm_init_dynwind () | |
0f2d19dd | 319 | { |
4845bbae | 320 | tc16_frame = scm_make_smob_type ("frame", 0); |
4845bbae MV |
321 | |
322 | tc16_winder = scm_make_smob_type ("winder", 0); | |
323 | ||
a0599745 | 324 | #include "libguile/dynwind.x" |
0f2d19dd | 325 | } |
89e00824 ML |
326 | |
327 | /* | |
328 | Local Variables: | |
329 | c-file-style: "gnu" | |
330 | End: | |
331 | */ |