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5556c175 | 1 | /* Copyright (C) 2010, 2011, 2012 Free Software Foundation, Inc. |
b9c100d0 AW |
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 | ||
9ede013f AW |
33 | #define PROMPT_ESCAPE_P(p) \ |
34 | (SCM_DYNSTACK_TAG_FLAGS (SCM_DYNSTACK_TAG (p)) \ | |
35 | & SCM_F_DYNSTACK_PROMPT_ESCAPE_ONLY) | |
3ccee391 | 36 | |
9ede013f | 37 | \f |
adaf86ec | 38 | |
9ede013f | 39 | |
9ede013f | 40 | /* Only to be called if the SCM_I_SETJMP returns 1 */ |
b8af64db | 41 | SCM |
572eef50 | 42 | scm_i_prompt_pop_abort_args_x (SCM vm) |
b8af64db AW |
43 | { |
44 | size_t i, n; | |
45 | SCM vals = SCM_EOL; | |
46 | ||
572eef50 | 47 | n = scm_to_size_t (SCM_VM_DATA (vm)->sp[0]); |
b8af64db | 48 | for (i = 0; i < n; i++) |
572eef50 | 49 | vals = scm_cons (SCM_VM_DATA (vm)->sp[-(i + 1)], vals); |
b8af64db AW |
50 | |
51 | /* The abort did reset the VM's registers, but then these values | |
52 | were pushed on; so we need to pop them ourselves. */ | |
572eef50 | 53 | SCM_VM_DATA (vm)->sp -= n + 1; |
b8af64db AW |
54 | /* FIXME NULLSTACK */ |
55 | ||
56 | return vals; | |
57 | } | |
58 | ||
59 | ||
cee1d22c AW |
60 | #ifdef WORDS_BIGENDIAN |
61 | #define OBJCODE_HEADER(main,meta) 0, 0, 0, main, 0, 0, 0, meta+8 | |
62 | #define META_HEADER(meta) 0, 0, 0, meta, 0, 0, 0, 0 | |
63 | #else | |
64 | #define OBJCODE_HEADER(main,meta) main, 0, 0, 0, meta+8, 0, 0, 0 | |
65 | #define META_HEADER(meta) meta, 0, 0, 0, 0, 0, 0, 0 | |
66 | #endif | |
67 | ||
5556c175 | 68 | #define OBJCODE_TAG SCM_MAKE_OBJCODE_TAG (SCM_OBJCODE_TYPE_STATIC, 0) |
cee1d22c | 69 | |
5556c175 | 70 | #if defined (SCM_ALIGNED) |
1c05a2a1 | 71 | #define SCM_DECLARE_STATIC_ALIGNED_ARRAY(type, sym) \ |
cee1d22c | 72 | static const type sym[] |
1c05a2a1 | 73 | #define SCM_STATIC_ALIGNED_ARRAY(alignment, type, sym) \ |
cee1d22c | 74 | static SCM_ALIGNED (alignment) const type sym[] |
cee1d22c AW |
75 | #define SCM_STATIC_OBJCODE(sym) \ |
76 | SCM_DECLARE_STATIC_ALIGNED_ARRAY (scm_t_uint8, sym##__bytecode); \ | |
77 | SCM_STATIC_ALIGNED_ARRAY (8, scm_t_cell, sym##__cells) = { \ | |
5556c175 | 78 | { SCM_PACK (OBJCODE_TAG), SCM_PACK (sym##__bytecode) }, \ |
cee1d22c AW |
79 | { SCM_BOOL_F, SCM_PACK (0) } \ |
80 | }; \ | |
81 | static const SCM sym = SCM_PACK (sym##__cells); \ | |
82 | SCM_STATIC_ALIGNED_ARRAY (8, scm_t_uint8, sym##__bytecode) | |
5556c175 AW |
83 | #else |
84 | #define SCM_STATIC_OBJCODE(sym) \ | |
85 | static SCM sym; \ | |
86 | static scm_t_uint8 *sym##_bytecode; \ | |
87 | SCM_SNARF_INIT(sym##_bytecode = scm_gc_malloc_pointerless (sizeof(sym##_bytecode__unaligned), "partial continuation stub"); \ | |
88 | memcpy (sym##_bytecode, sym##_bytecode__unaligned, sizeof(sym##_bytecode__unaligned));) \ | |
89 | SCM_SNARF_INIT(sym = scm_double_cell (OBJCODE_TAG, \ | |
90 | (scm_t_bits)sym##_bytecode, \ | |
91 | SCM_UNPACK (SCM_BOOL_F), \ | |
92 | 0);) \ | |
93 | static const scm_t_uint8 sym##_bytecode__unaligned[] | |
94 | #endif | |
95 | ||
cee1d22c | 96 | |
cee1d22c AW |
97 | SCM_STATIC_OBJCODE (cont_objcode) = { |
98 | /* Like in continuations.c, but with partial-cont-call. */ | |
99 | OBJCODE_HEADER (8, 19), | |
100 | /* leave args on the stack */ | |
101 | /* 0 */ scm_op_object_ref, 0, /* push scm_vm_cont object */ | |
9ede013f AW |
102 | /* 2 */ scm_op_partial_cont_call, /* and go! */ |
103 | /* 3 */ scm_op_nop, | |
104 | /* 4 */ scm_op_nop, scm_op_nop, scm_op_nop, scm_op_nop, /* pad to 8 bytes */ | |
cee1d22c AW |
105 | /* 8 */ |
106 | ||
107 | /* We could put some meta-info to say that this proc is a continuation. Not sure | |
108 | how to do that, though. */ | |
109 | META_HEADER (19), | |
110 | /* 0 */ scm_op_make_eol, /* bindings */ | |
111 | /* 1 */ scm_op_make_eol, /* sources */ | |
9ede013f | 112 | /* 2 */ scm_op_make_int8, 0, scm_op_make_int8, 3, /* arity: from ip 0 to ip 3 */ |
cee1d22c AW |
113 | /* 6 */ scm_op_make_int8_0, /* the arity is 0 required args */ |
114 | /* 7 */ scm_op_make_int8_0, /* 0 optionals */ | |
115 | /* 8 */ scm_op_make_true, /* and a rest arg */ | |
116 | /* 9 */ scm_op_list, 0, 5, /* make a list of those 5 vals */ | |
117 | /* 12 */ scm_op_list, 0, 1, /* and the arities will be a list of that one list */ | |
118 | /* 15 */ scm_op_list, 0, 3, /* pack bindings, sources, and arities into list */ | |
119 | /* 18 */ scm_op_return /* and return */ | |
120 | /* 19 */ | |
121 | }; | |
122 | ||
123 | ||
124 | static SCM | |
9d381ba4 AW |
125 | reify_partial_continuation (SCM vm, |
126 | SCM *saved_fp, SCM *saved_sp, scm_t_uint8 *saved_ip, | |
127 | scm_i_jmp_buf *saved_registers, | |
9ede013f | 128 | scm_t_dynstack *dynstack, |
9d381ba4 | 129 | scm_i_jmp_buf *current_registers) |
cee1d22c | 130 | { |
9ede013f | 131 | SCM vm_cont, ret; |
cee1d22c AW |
132 | scm_t_uint32 flags; |
133 | ||
cee1d22c | 134 | flags = SCM_F_VM_CONT_PARTIAL; |
9d381ba4 AW |
135 | /* If we are aborting to a prompt that has the same registers as those |
136 | of the abort, it means there are no intervening C frames on the | |
137 | stack, and so the continuation can be relocated elsewhere on the | |
138 | stack: it is rewindable. */ | |
139 | if (saved_registers && saved_registers == current_registers) | |
cee1d22c AW |
140 | flags |= SCM_F_VM_CONT_REWINDABLE; |
141 | ||
6d804376 AW |
142 | /* Since non-escape continuations should begin with a thunk application, the |
143 | first bit of the stack should be a frame, with the saved fp equal to the fp | |
144 | that was current when the prompt was made. */ | |
9d381ba4 | 145 | if ((SCM*)SCM_UNPACK (saved_sp[1]) != saved_fp) |
6d804376 AW |
146 | abort (); |
147 | ||
148 | /* Capture from the top of the thunk application frame up to the end. Set an | |
149 | MVRA only, as the post-abort code is in an MV context. */ | |
9d381ba4 | 150 | vm_cont = scm_i_vm_capture_stack (saved_sp + 4, |
cee1d22c AW |
151 | SCM_VM_DATA (vm)->fp, |
152 | SCM_VM_DATA (vm)->sp, | |
6d804376 AW |
153 | NULL, |
154 | SCM_VM_DATA (vm)->ip, | |
9ede013f | 155 | dynstack, |
cee1d22c AW |
156 | flags); |
157 | ||
158 | ret = scm_make_program (cont_objcode, | |
9ede013f | 159 | scm_c_make_vector (1, vm_cont), |
cee1d22c AW |
160 | SCM_BOOL_F); |
161 | SCM_SET_CELL_WORD_0 (ret, | |
2150e9a8 | 162 | SCM_CELL_WORD_0 (ret) | SCM_F_PROGRAM_IS_PARTIAL_CONTINUATION); |
cee1d22c AW |
163 | return ret; |
164 | } | |
165 | ||
d2964315 | 166 | void |
9d381ba4 AW |
167 | scm_c_abort (SCM vm, SCM tag, size_t n, SCM *argv, |
168 | scm_i_jmp_buf *current_registers) | |
eaefabee | 169 | { |
9ede013f AW |
170 | SCM cont; |
171 | scm_t_dynstack *dynstack = &SCM_I_CURRENT_THREAD->dynstack; | |
172 | scm_t_bits *prompt; | |
9ede013f | 173 | scm_t_dynstack_prompt_flags flags; |
9d381ba4 AW |
174 | SCM *fp, *sp; |
175 | scm_t_uint8 *ip; | |
176 | scm_i_jmp_buf *registers; | |
eaefabee AW |
177 | size_t i; |
178 | ||
9d381ba4 AW |
179 | prompt = scm_dynstack_find_prompt (dynstack, tag, |
180 | &flags, &fp, &sp, &ip, ®isters); | |
9ede013f AW |
181 | |
182 | if (!prompt) | |
9f074518 | 183 | scm_misc_error ("abort", "Abort to unknown prompt", scm_list_1 (tag)); |
eaefabee | 184 | |
9ede013f AW |
185 | /* Only reify if the continuation referenced in the handler. */ |
186 | if (flags & SCM_F_DYNSTACK_PROMPT_ESCAPE_ONLY) | |
187 | cont = SCM_BOOL_F; | |
188 | else | |
189 | { | |
190 | scm_t_dynstack *captured; | |
cee1d22c | 191 | |
9ede013f | 192 | captured = scm_dynstack_capture (dynstack, SCM_DYNSTACK_NEXT (prompt)); |
9d381ba4 AW |
193 | cont = reify_partial_continuation (vm, fp, sp, ip, registers, captured, |
194 | current_registers); | |
9ede013f | 195 | } |
8684029d | 196 | |
9ede013f AW |
197 | /* Unwind. */ |
198 | scm_dynstack_unwind (dynstack, prompt); | |
eaefabee | 199 | |
8684029d LC |
200 | /* Unwinding may have changed the current thread's VM, so use the |
201 | new one. */ | |
202 | vm = scm_the_vm (); | |
203 | ||
eaefabee | 204 | /* Restore VM regs */ |
9d381ba4 AW |
205 | SCM_VM_DATA (vm)->fp = fp; |
206 | SCM_VM_DATA (vm)->sp = sp; | |
207 | SCM_VM_DATA (vm)->ip = ip; | |
eaefabee | 208 | |
9ede013f | 209 | /* Since we're jumping down, we should always have enough space. */ |
eaefabee AW |
210 | if (SCM_VM_DATA (vm)->sp + n + 1 >= SCM_VM_DATA (vm)->stack_limit) |
211 | abort (); | |
212 | ||
213 | /* Push vals */ | |
cee1d22c | 214 | *(++(SCM_VM_DATA (vm)->sp)) = cont; |
eaefabee AW |
215 | for (i = 0; i < n; i++) |
216 | *(++(SCM_VM_DATA (vm)->sp)) = argv[i]; | |
217 | *(++(SCM_VM_DATA (vm)->sp)) = scm_from_size_t (n+1); /* +1 for continuation */ | |
218 | ||
219 | /* Jump! */ | |
9d381ba4 | 220 | SCM_I_LONGJMP (*registers, 1); |
eaefabee AW |
221 | |
222 | /* Shouldn't get here */ | |
223 | abort (); | |
224 | } | |
adaf86ec | 225 | |
2d026f04 | 226 | SCM_DEFINE (scm_at_abort, "@abort", 2, 0, 0, (SCM tag, SCM args), |
747022e4 | 227 | "Abort to the nearest prompt with tag @var{tag}.") |
2d026f04 | 228 | #define FUNC_NAME s_scm_at_abort |
b9c100d0 | 229 | { |
747022e4 | 230 | SCM *argv; |
2b14df4b AW |
231 | size_t i; |
232 | long n; | |
747022e4 AW |
233 | |
234 | SCM_VALIDATE_LIST_COPYLEN (SCM_ARG2, args, n); | |
235 | argv = alloca (sizeof (SCM)*n); | |
236 | for (i = 0; i < n; i++, args = scm_cdr (args)) | |
237 | argv[i] = scm_car (args); | |
238 | ||
9d381ba4 | 239 | scm_c_abort (scm_the_vm (), tag, n, argv, NULL); |
747022e4 | 240 | |
2d026f04 AW |
241 | /* Oh, what, you're still here? The abort must have been reinstated. Actually, |
242 | that's quite impossible, given that we're already in C-land here, so... | |
243 | abort! */ | |
244 | ||
245 | abort (); | |
b9c100d0 | 246 | } |
747022e4 | 247 | #undef FUNC_NAME |
b9c100d0 | 248 | |
3ccee391 AW |
249 | void |
250 | scm_init_control (void) | |
b9c100d0 | 251 | { |
69c96006 | 252 | #include "libguile/control.x" |
b9c100d0 AW |
253 | } |
254 | ||
255 | /* | |
256 | Local Variables: | |
257 | c-file-style: "gnu" | |
258 | End: | |
259 | */ |