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b9c100d0 AW |
1 | /* Copyright (C) 2010 Free Software Foundation, Inc. |
2 | * | |
3 | * This library is free software; you can redistribute it and/or | |
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. | |
7 | * | |
8 | * This library is distributed in the hope that it will be useful, but | |
9 | * 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. | |
12 | * | |
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 | |
15 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
16 | * 02110-1301 USA | |
17 | */ | |
18 | ||
19 | #if HAVE_CONFIG_H | |
20 | # include <config.h> | |
21 | #endif | |
22 | ||
cdd47ec7 LC |
23 | #include <alloca.h> |
24 | ||
b9c100d0 AW |
25 | #include "libguile/_scm.h" |
26 | #include "libguile/control.h" | |
cee1d22c AW |
27 | #include "libguile/objcodes.h" |
28 | #include "libguile/instructions.h" | |
adaf86ec | 29 | #include "libguile/vm.h" |
b9c100d0 AW |
30 | |
31 | \f | |
32 | ||
3ccee391 | 33 | |
adaf86ec | 34 | SCM |
d2964315 | 35 | scm_c_make_prompt (SCM k, SCM *fp, SCM *sp, scm_t_uint8 *abort_ip, |
adbdfd6d AW |
36 | scm_t_uint8 escape_only_p, scm_t_int64 vm_cookie, |
37 | SCM winds) | |
adaf86ec AW |
38 | { |
39 | scm_t_bits tag; | |
adaf86ec AW |
40 | struct scm_prompt_registers *regs; |
41 | ||
42 | tag = scm_tc7_prompt; | |
adaf86ec | 43 | if (escape_only_p) |
211fcbc8 | 44 | tag |= (SCM_F_PROMPT_ESCAPE<<8); |
adaf86ec AW |
45 | |
46 | regs = scm_gc_malloc_pointerless (sizeof (*regs), "prompt registers"); | |
d2964315 AW |
47 | regs->fp = fp; |
48 | regs->sp = sp; | |
49 | regs->ip = abort_ip; | |
2d026f04 | 50 | regs->cookie = vm_cookie; |
adaf86ec | 51 | |
adbdfd6d AW |
52 | return scm_double_cell (tag, SCM_UNPACK (k), (scm_t_bits)regs, |
53 | SCM_UNPACK (winds)); | |
adaf86ec AW |
54 | } |
55 | ||
b8af64db AW |
56 | /* Only to be called if the SCM_PROMPT_SETJMP returns 1 */ |
57 | SCM | |
58 | scm_i_prompt_pop_abort_args_x (SCM prompt) | |
59 | { | |
60 | size_t i, n; | |
61 | SCM vals = SCM_EOL; | |
62 | ||
63 | n = scm_to_size_t (SCM_PROMPT_REGISTERS (prompt)->sp[0]); | |
64 | for (i = 0; i < n; i++) | |
65 | vals = scm_cons (SCM_PROMPT_REGISTERS (prompt)->sp[-(i + 1)], vals); | |
66 | ||
67 | /* The abort did reset the VM's registers, but then these values | |
68 | were pushed on; so we need to pop them ourselves. */ | |
69 | SCM_VM_DATA (scm_the_vm ())->sp -= n + 1; | |
70 | /* FIXME NULLSTACK */ | |
71 | ||
72 | return vals; | |
73 | } | |
74 | ||
75 | ||
cee1d22c AW |
76 | #ifdef WORDS_BIGENDIAN |
77 | #define OBJCODE_HEADER(main,meta) 0, 0, 0, main, 0, 0, 0, meta+8 | |
78 | #define META_HEADER(meta) 0, 0, 0, meta, 0, 0, 0, 0 | |
79 | #else | |
80 | #define OBJCODE_HEADER(main,meta) main, 0, 0, 0, meta+8, 0, 0, 0 | |
81 | #define META_HEADER(meta) meta, 0, 0, 0, 0, 0, 0, 0 | |
82 | #endif | |
83 | ||
cee1d22c AW |
84 | #define ALIGN_PTR(type,p,align) (type*)(ROUND_UP (((scm_t_bits)p), align)) |
85 | ||
86 | #ifdef SCM_ALIGNED | |
1c05a2a1 | 87 | #define SCM_DECLARE_STATIC_ALIGNED_ARRAY(type, sym) \ |
cee1d22c | 88 | static const type sym[] |
1c05a2a1 | 89 | #define SCM_STATIC_ALIGNED_ARRAY(alignment, type, sym) \ |
cee1d22c AW |
90 | static SCM_ALIGNED (alignment) const type sym[] |
91 | #else | |
1c05a2a1 | 92 | #define SCM_DECLARE_STATIC_ALIGNED_ARRAY(type, sym) \ |
cee1d22c AW |
93 | static type *sym |
94 | #define SCM_STATIC_ALIGNED_ARRAY(alignment, type, sym) \ | |
1c05a2a1 | 95 | SCM_SNARF_INIT(sym = scm_malloc_pointerless (sizeof(sym##__unaligned); \ |
cee1d22c AW |
96 | memcpy (sym, sym##__unaligned, sizeof(sym##__unaligned));) \ |
97 | static type *sym = NULL; \ | |
98 | static const type sym##__unaligned[] | |
99 | #endif | |
100 | ||
101 | #define STATIC_OBJCODE_TAG \ | |
102 | SCM_PACK (scm_tc7_objcode | (SCM_F_OBJCODE_IS_STATIC << 8)) | |
103 | ||
104 | #define SCM_STATIC_OBJCODE(sym) \ | |
105 | SCM_DECLARE_STATIC_ALIGNED_ARRAY (scm_t_uint8, sym##__bytecode); \ | |
106 | SCM_STATIC_ALIGNED_ARRAY (8, scm_t_cell, sym##__cells) = { \ | |
107 | { STATIC_OBJCODE_TAG, SCM_PACK (sym##__bytecode) }, \ | |
108 | { SCM_BOOL_F, SCM_PACK (0) } \ | |
109 | }; \ | |
110 | static const SCM sym = SCM_PACK (sym##__cells); \ | |
111 | SCM_STATIC_ALIGNED_ARRAY (8, scm_t_uint8, sym##__bytecode) | |
112 | ||
113 | ||
114 | SCM_STATIC_OBJCODE (cont_objcode) = { | |
115 | /* Like in continuations.c, but with partial-cont-call. */ | |
116 | OBJCODE_HEADER (8, 19), | |
117 | /* leave args on the stack */ | |
118 | /* 0 */ scm_op_object_ref, 0, /* push scm_vm_cont object */ | |
119 | /* 2 */ scm_op_object_ref, 1, /* push internal winds */ | |
9a1c6f1f AW |
120 | /* 4 */ scm_op_partial_cont_call, /* and go! */ |
121 | /* 5 */ scm_op_nop, scm_op_nop, scm_op_nop, /* pad to 8 bytes */ | |
cee1d22c AW |
122 | /* 8 */ |
123 | ||
124 | /* We could put some meta-info to say that this proc is a continuation. Not sure | |
125 | how to do that, though. */ | |
126 | META_HEADER (19), | |
127 | /* 0 */ scm_op_make_eol, /* bindings */ | |
128 | /* 1 */ scm_op_make_eol, /* sources */ | |
9a1c6f1f | 129 | /* 2 */ scm_op_make_int8, 0, scm_op_make_int8, 5, /* arity: from ip 0 to ip 7 */ |
cee1d22c AW |
130 | /* 6 */ scm_op_make_int8_0, /* the arity is 0 required args */ |
131 | /* 7 */ scm_op_make_int8_0, /* 0 optionals */ | |
132 | /* 8 */ scm_op_make_true, /* and a rest arg */ | |
133 | /* 9 */ scm_op_list, 0, 5, /* make a list of those 5 vals */ | |
134 | /* 12 */ scm_op_list, 0, 1, /* and the arities will be a list of that one list */ | |
135 | /* 15 */ scm_op_list, 0, 3, /* pack bindings, sources, and arities into list */ | |
136 | /* 18 */ scm_op_return /* and return */ | |
137 | /* 19 */ | |
138 | }; | |
139 | ||
140 | ||
141 | static SCM | |
142 | reify_partial_continuation (SCM vm, SCM prompt, SCM extwinds, | |
143 | scm_t_int64 cookie) | |
144 | { | |
145 | SCM vm_cont, dynwinds, intwinds = SCM_EOL, ret; | |
146 | scm_t_uint32 flags; | |
147 | ||
148 | /* No need to reify if the continuation is never referenced in the handler. */ | |
149 | if (SCM_PROMPT_ESCAPE_P (prompt)) | |
150 | return SCM_BOOL_F; | |
151 | ||
152 | dynwinds = scm_i_dynwinds (); | |
153 | while (!scm_is_eq (dynwinds, extwinds)) | |
154 | { | |
155 | intwinds = scm_cons (scm_car (dynwinds), intwinds); | |
156 | dynwinds = scm_cdr (dynwinds); | |
157 | } | |
158 | ||
159 | flags = SCM_F_VM_CONT_PARTIAL; | |
160 | if (cookie >= 0 && SCM_PROMPT_REGISTERS (prompt)->cookie == cookie) | |
161 | flags |= SCM_F_VM_CONT_REWINDABLE; | |
162 | ||
6d804376 AW |
163 | /* Since non-escape continuations should begin with a thunk application, the |
164 | first bit of the stack should be a frame, with the saved fp equal to the fp | |
165 | that was current when the prompt was made. */ | |
166 | if ((SCM*)(SCM_PROMPT_REGISTERS (prompt)->sp[1]) | |
167 | != SCM_PROMPT_REGISTERS (prompt)->fp) | |
168 | abort (); | |
169 | ||
170 | /* Capture from the top of the thunk application frame up to the end. Set an | |
171 | MVRA only, as the post-abort code is in an MV context. */ | |
172 | vm_cont = scm_i_vm_capture_stack (SCM_PROMPT_REGISTERS (prompt)->sp + 4, | |
cee1d22c AW |
173 | SCM_VM_DATA (vm)->fp, |
174 | SCM_VM_DATA (vm)->sp, | |
6d804376 AW |
175 | NULL, |
176 | SCM_VM_DATA (vm)->ip, | |
cee1d22c AW |
177 | flags); |
178 | ||
179 | ret = scm_make_program (cont_objcode, | |
9a1c6f1f | 180 | scm_vector (scm_list_2 (vm_cont, intwinds)), |
cee1d22c AW |
181 | SCM_BOOL_F); |
182 | SCM_SET_CELL_WORD_0 (ret, | |
2150e9a8 | 183 | SCM_CELL_WORD_0 (ret) | SCM_F_PROGRAM_IS_PARTIAL_CONTINUATION); |
cee1d22c AW |
184 | return ret; |
185 | } | |
186 | ||
d2964315 | 187 | void |
cee1d22c | 188 | scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv, scm_t_int64 cookie) |
eaefabee | 189 | { |
cee1d22c | 190 | SCM cont, winds, prompt = SCM_BOOL_F; |
eaefabee AW |
191 | long delta; |
192 | size_t i; | |
193 | ||
194 | /* Search the wind list for an appropriate prompt. | |
195 | "Waiter, please bring us the wind list." */ | |
196 | for (winds = scm_i_dynwinds (), delta = 0; | |
197 | scm_is_pair (winds); | |
198 | winds = SCM_CDR (winds), delta++) | |
199 | { | |
200 | SCM elt = SCM_CAR (winds); | |
201 | if (SCM_PROMPT_P (elt) && scm_is_eq (SCM_PROMPT_TAG (elt), tag)) | |
202 | { | |
203 | prompt = elt; | |
204 | break; | |
205 | } | |
206 | } | |
207 | ||
c6a32a2c | 208 | /* If we didn't find anything, raise an error. */ |
eaefabee | 209 | if (scm_is_false (prompt)) |
9f074518 | 210 | scm_misc_error ("abort", "Abort to unknown prompt", scm_list_1 (tag)); |
eaefabee | 211 | |
cee1d22c AW |
212 | cont = reify_partial_continuation (vm, prompt, winds, cookie); |
213 | ||
eaefabee AW |
214 | /* Unwind once more, beyond the prompt. */ |
215 | winds = SCM_CDR (winds), delta++; | |
8684029d | 216 | |
eaefabee AW |
217 | /* Unwind */ |
218 | scm_dowinds (winds, delta); | |
219 | ||
8684029d LC |
220 | /* Unwinding may have changed the current thread's VM, so use the |
221 | new one. */ | |
222 | vm = scm_the_vm (); | |
223 | ||
eaefabee AW |
224 | /* Restore VM regs */ |
225 | SCM_VM_DATA (vm)->fp = SCM_PROMPT_REGISTERS (prompt)->fp; | |
226 | SCM_VM_DATA (vm)->sp = SCM_PROMPT_REGISTERS (prompt)->sp; | |
227 | SCM_VM_DATA (vm)->ip = SCM_PROMPT_REGISTERS (prompt)->ip; | |
228 | ||
229 | /* Since we're jumping down, we should always have enough space */ | |
230 | if (SCM_VM_DATA (vm)->sp + n + 1 >= SCM_VM_DATA (vm)->stack_limit) | |
231 | abort (); | |
232 | ||
233 | /* Push vals */ | |
cee1d22c | 234 | *(++(SCM_VM_DATA (vm)->sp)) = cont; |
eaefabee AW |
235 | for (i = 0; i < n; i++) |
236 | *(++(SCM_VM_DATA (vm)->sp)) = argv[i]; | |
237 | *(++(SCM_VM_DATA (vm)->sp)) = scm_from_size_t (n+1); /* +1 for continuation */ | |
238 | ||
239 | /* Jump! */ | |
240 | SCM_I_LONGJMP (SCM_PROMPT_REGISTERS (prompt)->regs, 1); | |
241 | ||
242 | /* Shouldn't get here */ | |
243 | abort (); | |
244 | } | |
adaf86ec | 245 | |
2d026f04 | 246 | SCM_DEFINE (scm_at_abort, "@abort", 2, 0, 0, (SCM tag, SCM args), |
747022e4 | 247 | "Abort to the nearest prompt with tag @var{tag}.") |
2d026f04 | 248 | #define FUNC_NAME s_scm_at_abort |
b9c100d0 | 249 | { |
747022e4 AW |
250 | SCM *argv; |
251 | size_t i, n; | |
252 | ||
253 | SCM_VALIDATE_LIST_COPYLEN (SCM_ARG2, args, n); | |
254 | argv = alloca (sizeof (SCM)*n); | |
255 | for (i = 0; i < n; i++, args = scm_cdr (args)) | |
256 | argv[i] = scm_car (args); | |
257 | ||
cee1d22c | 258 | scm_c_abort (scm_the_vm (), tag, n, argv, -1); |
747022e4 | 259 | |
2d026f04 AW |
260 | /* Oh, what, you're still here? The abort must have been reinstated. Actually, |
261 | that's quite impossible, given that we're already in C-land here, so... | |
262 | abort! */ | |
263 | ||
264 | abort (); | |
b9c100d0 | 265 | } |
747022e4 | 266 | #undef FUNC_NAME |
b9c100d0 | 267 | |
bbb2ecd1 AW |
268 | void |
269 | scm_i_prompt_print (SCM exp, SCM port, scm_print_state *pstate SCM_UNUSED) | |
270 | { | |
271 | scm_puts ("#<prompt ", port); | |
272 | scm_intprint (SCM_UNPACK (exp), 16, port); | |
273 | scm_putc ('>', port); | |
274 | } | |
275 | ||
3ccee391 AW |
276 | void |
277 | scm_init_control (void) | |
b9c100d0 | 278 | { |
69c96006 | 279 | #include "libguile/control.x" |
b9c100d0 AW |
280 | } |
281 | ||
282 | /* | |
283 | Local Variables: | |
284 | c-file-style: "gnu" | |
285 | End: | |
286 | */ |