1 /*
2 ** FFI library.
3 ** Copyright (C) 2005-2021 Mike Pall. See Copyright Notice in luajit.h
4 */
5
6 #define lib_ffi_c
7 #define LUA_LIB
8
9 #include <errno.h>
10
11 #include "lua.h"
12 #include "lauxlib.h"
13 #include "lualib.h"
14
15 #include "lj_obj.h"
16
17 #if LJ_HASFFI
18
19 #include "lj_gc.h"
20 #include "lj_err.h"
21 #include "lj_str.h"
22 #include "lj_tab.h"
23 #include "lj_meta.h"
24 #include "lj_ctype.h"
25 #include "lj_cparse.h"
26 #include "lj_cdata.h"
27 #include "lj_cconv.h"
28 #include "lj_carith.h"
29 #include "lj_ccall.h"
30 #include "lj_ccallback.h"
31 #include "lj_clib.h"
32 #include "lj_strfmt.h"
33 #include "lj_ff.h"
34 #include "lj_lib.h"
35
36 /* -- C type checks ------------------------------------------------------- */
37
38 /* Check first argument for a C type and returns its ID. */
ffi_checkctype(lua_State * L,CTState * cts,TValue * param)39 static CTypeID ffi_checkctype(lua_State *L, CTState *cts, TValue *param)
40 {
41 TValue *o = L->base;
42 if (!(o < L->top)) {
43 err_argtype:
44 lj_err_argtype(L, 1, "C type");
45 }
46 if (tvisstr(o)) { /* Parse an abstract C type declaration. */
47 GCstr *s = strV(o);
48 CPState cp;
49 int errcode;
50 cp.L = L;
51 cp.cts = cts;
52 cp.srcname = strdata(s);
53 cp.p = strdata(s);
54 cp.param = param;
55 cp.mode = CPARSE_MODE_ABSTRACT|CPARSE_MODE_NOIMPLICIT;
56 errcode = lj_cparse(&cp);
57 if (errcode) lj_err_throw(L, errcode); /* Propagate errors. */
58 return cp.val.id;
59 } else {
60 GCcdata *cd;
61 if (!tviscdata(o)) goto err_argtype;
62 if (param && param < L->top) lj_err_arg(L, 1, LJ_ERR_FFI_NUMPARAM);
63 cd = cdataV(o);
64 return cd->ctypeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) : cd->ctypeid;
65 }
66 }
67
68 /* Check argument for C data and return it. */
ffi_checkcdata(lua_State * L,int narg)69 static GCcdata *ffi_checkcdata(lua_State *L, int narg)
70 {
71 TValue *o = L->base + narg-1;
72 if (!(o < L->top && tviscdata(o)))
73 lj_err_argt(L, narg, LUA_TCDATA);
74 return cdataV(o);
75 }
76
77 /* Convert argument to C pointer. */
ffi_checkptr(lua_State * L,int narg,CTypeID id)78 static void *ffi_checkptr(lua_State *L, int narg, CTypeID id)
79 {
80 CTState *cts = ctype_cts(L);
81 TValue *o = L->base + narg-1;
82 void *p;
83 if (o >= L->top)
84 lj_err_arg(L, narg, LJ_ERR_NOVAL);
85 lj_cconv_ct_tv(cts, ctype_get(cts, id), (uint8_t *)&p, o, CCF_ARG(narg));
86 return p;
87 }
88
89 /* Convert argument to int32_t. */
ffi_checkint(lua_State * L,int narg)90 static int32_t ffi_checkint(lua_State *L, int narg)
91 {
92 CTState *cts = ctype_cts(L);
93 TValue *o = L->base + narg-1;
94 int32_t i;
95 if (o >= L->top)
96 lj_err_arg(L, narg, LJ_ERR_NOVAL);
97 lj_cconv_ct_tv(cts, ctype_get(cts, CTID_INT32), (uint8_t *)&i, o,
98 CCF_ARG(narg));
99 return i;
100 }
101
102 /* -- C type metamethods -------------------------------------------------- */
103
104 #define LJLIB_MODULE_ffi_meta
105
106 /* Handle ctype __index/__newindex metamethods. */
ffi_index_meta(lua_State * L,CTState * cts,CType * ct,MMS mm)107 static int ffi_index_meta(lua_State *L, CTState *cts, CType *ct, MMS mm)
108 {
109 CTypeID id = ctype_typeid(cts, ct);
110 cTValue *tv = lj_ctype_meta(cts, id, mm);
111 TValue *base = L->base;
112 if (!tv) {
113 const char *s;
114 err_index:
115 s = strdata(lj_ctype_repr(L, id, NULL));
116 if (tvisstr(L->base+1)) {
117 lj_err_callerv(L, LJ_ERR_FFI_BADMEMBER, s, strVdata(L->base+1));
118 } else {
119 const char *key = tviscdata(L->base+1) ?
120 strdata(lj_ctype_repr(L, cdataV(L->base+1)->ctypeid, NULL)) :
121 lj_typename(L->base+1);
122 lj_err_callerv(L, LJ_ERR_FFI_BADIDXW, s, key);
123 }
124 }
125 if (!tvisfunc(tv)) {
126 if (mm == MM_index) {
127 cTValue *o = lj_meta_tget(L, tv, base+1);
128 if (o) {
129 if (tvisnil(o)) goto err_index;
130 copyTV(L, L->top-1, o);
131 return 1;
132 }
133 } else {
134 TValue *o = lj_meta_tset(L, tv, base+1);
135 if (o) {
136 copyTV(L, o, base+2);
137 return 0;
138 }
139 }
140 copyTV(L, base, L->top);
141 tv = L->top-1-LJ_FR2;
142 }
143 return lj_meta_tailcall(L, tv);
144 }
145
146 LJLIB_CF(ffi_meta___index) LJLIB_REC(cdata_index 0)
147 {
148 CTState *cts = ctype_cts(L);
149 CTInfo qual = 0;
150 CType *ct;
151 uint8_t *p;
152 TValue *o = L->base;
153 if (!(o+1 < L->top && tviscdata(o))) /* Also checks for presence of key. */
154 lj_err_argt(L, 1, LUA_TCDATA);
155 ct = lj_cdata_index(cts, cdataV(o), o+1, &p, &qual);
156 if ((qual & 1))
157 return ffi_index_meta(L, cts, ct, MM_index);
158 if (lj_cdata_get(cts, ct, L->top-1, p))
159 lj_gc_check(L);
160 return 1;
161 }
162
163 LJLIB_CF(ffi_meta___newindex) LJLIB_REC(cdata_index 1)
164 {
165 CTState *cts = ctype_cts(L);
166 CTInfo qual = 0;
167 CType *ct;
168 uint8_t *p;
169 TValue *o = L->base;
170 if (!(o+2 < L->top && tviscdata(o))) /* Also checks for key and value. */
171 lj_err_argt(L, 1, LUA_TCDATA);
172 ct = lj_cdata_index(cts, cdataV(o), o+1, &p, &qual);
173 if ((qual & 1)) {
174 if ((qual & CTF_CONST))
175 lj_err_caller(L, LJ_ERR_FFI_WRCONST);
176 return ffi_index_meta(L, cts, ct, MM_newindex);
177 }
178 lj_cdata_set(cts, ct, p, o+2, qual);
179 return 0;
180 }
181
182 /* Common handler for cdata arithmetic. */
ffi_arith(lua_State * L)183 static int ffi_arith(lua_State *L)
184 {
185 MMS mm = (MMS)(curr_func(L)->c.ffid - (int)FF_ffi_meta___eq + (int)MM_eq);
186 return lj_carith_op(L, mm);
187 }
188
189 /* The following functions must be in contiguous ORDER MM. */
LJLIB_REC(cdata_arith MM_eq)190 LJLIB_CF(ffi_meta___eq) LJLIB_REC(cdata_arith MM_eq)
191 {
192 return ffi_arith(L);
193 }
194
LJLIB_REC(cdata_arith MM_len)195 LJLIB_CF(ffi_meta___len) LJLIB_REC(cdata_arith MM_len)
196 {
197 return ffi_arith(L);
198 }
199
LJLIB_REC(cdata_arith MM_lt)200 LJLIB_CF(ffi_meta___lt) LJLIB_REC(cdata_arith MM_lt)
201 {
202 return ffi_arith(L);
203 }
204
LJLIB_REC(cdata_arith MM_le)205 LJLIB_CF(ffi_meta___le) LJLIB_REC(cdata_arith MM_le)
206 {
207 return ffi_arith(L);
208 }
209
LJLIB_REC(cdata_arith MM_concat)210 LJLIB_CF(ffi_meta___concat) LJLIB_REC(cdata_arith MM_concat)
211 {
212 return ffi_arith(L);
213 }
214
215 /* Forward declaration. */
216 static int lj_cf_ffi_new(lua_State *L);
217
LJLIB_REC(cdata_call)218 LJLIB_CF(ffi_meta___call) LJLIB_REC(cdata_call)
219 {
220 CTState *cts = ctype_cts(L);
221 GCcdata *cd = ffi_checkcdata(L, 1);
222 CTypeID id = cd->ctypeid;
223 CType *ct;
224 cTValue *tv;
225 MMS mm = MM_call;
226 if (cd->ctypeid == CTID_CTYPEID) {
227 id = *(CTypeID *)cdataptr(cd);
228 mm = MM_new;
229 } else {
230 int ret = lj_ccall_func(L, cd);
231 if (ret >= 0)
232 return ret;
233 }
234 /* Handle ctype __call/__new metamethod. */
235 ct = ctype_raw(cts, id);
236 if (ctype_isptr(ct->info)) id = ctype_cid(ct->info);
237 tv = lj_ctype_meta(cts, id, mm);
238 if (tv)
239 return lj_meta_tailcall(L, tv);
240 else if (mm == MM_call)
241 lj_err_callerv(L, LJ_ERR_FFI_BADCALL, strdata(lj_ctype_repr(L, id, NULL)));
242 return lj_cf_ffi_new(L);
243 }
244
LJLIB_REC(cdata_arith MM_add)245 LJLIB_CF(ffi_meta___add) LJLIB_REC(cdata_arith MM_add)
246 {
247 return ffi_arith(L);
248 }
249
LJLIB_REC(cdata_arith MM_sub)250 LJLIB_CF(ffi_meta___sub) LJLIB_REC(cdata_arith MM_sub)
251 {
252 return ffi_arith(L);
253 }
254
LJLIB_REC(cdata_arith MM_mul)255 LJLIB_CF(ffi_meta___mul) LJLIB_REC(cdata_arith MM_mul)
256 {
257 return ffi_arith(L);
258 }
259
LJLIB_REC(cdata_arith MM_div)260 LJLIB_CF(ffi_meta___div) LJLIB_REC(cdata_arith MM_div)
261 {
262 return ffi_arith(L);
263 }
264
LJLIB_REC(cdata_arith MM_mod)265 LJLIB_CF(ffi_meta___mod) LJLIB_REC(cdata_arith MM_mod)
266 {
267 return ffi_arith(L);
268 }
269
LJLIB_REC(cdata_arith MM_pow)270 LJLIB_CF(ffi_meta___pow) LJLIB_REC(cdata_arith MM_pow)
271 {
272 return ffi_arith(L);
273 }
274
LJLIB_REC(cdata_arith MM_unm)275 LJLIB_CF(ffi_meta___unm) LJLIB_REC(cdata_arith MM_unm)
276 {
277 return ffi_arith(L);
278 }
279 /* End of contiguous ORDER MM. */
280
LJLIB_CF(ffi_meta___tostring)281 LJLIB_CF(ffi_meta___tostring)
282 {
283 GCcdata *cd = ffi_checkcdata(L, 1);
284 const char *msg = "cdata<%s>: %p";
285 CTypeID id = cd->ctypeid;
286 void *p = cdataptr(cd);
287 if (id == CTID_CTYPEID) {
288 msg = "ctype<%s>";
289 id = *(CTypeID *)p;
290 } else {
291 CTState *cts = ctype_cts(L);
292 CType *ct = ctype_raw(cts, id);
293 if (ctype_isref(ct->info)) {
294 p = *(void **)p;
295 ct = ctype_rawchild(cts, ct);
296 }
297 if (ctype_iscomplex(ct->info)) {
298 setstrV(L, L->top-1, lj_ctype_repr_complex(L, cdataptr(cd), ct->size));
299 goto checkgc;
300 } else if (ct->size == 8 && ctype_isinteger(ct->info)) {
301 setstrV(L, L->top-1, lj_ctype_repr_int64(L, *(uint64_t *)cdataptr(cd),
302 (ct->info & CTF_UNSIGNED)));
303 goto checkgc;
304 } else if (ctype_isfunc(ct->info)) {
305 p = *(void **)p;
306 } else if (ctype_isenum(ct->info)) {
307 msg = "cdata<%s>: %d";
308 p = (void *)(uintptr_t)*(uint32_t **)p;
309 } else {
310 if (ctype_isptr(ct->info)) {
311 p = cdata_getptr(p, ct->size);
312 ct = ctype_rawchild(cts, ct);
313 }
314 if (ctype_isstruct(ct->info) || ctype_isvector(ct->info)) {
315 /* Handle ctype __tostring metamethod. */
316 cTValue *tv = lj_ctype_meta(cts, ctype_typeid(cts, ct), MM_tostring);
317 if (tv)
318 return lj_meta_tailcall(L, tv);
319 }
320 }
321 }
322 lj_strfmt_pushf(L, msg, strdata(lj_ctype_repr(L, id, NULL)), p);
323 checkgc:
324 lj_gc_check(L);
325 return 1;
326 }
327
ffi_pairs(lua_State * L,MMS mm)328 static int ffi_pairs(lua_State *L, MMS mm)
329 {
330 CTState *cts = ctype_cts(L);
331 CTypeID id = ffi_checkcdata(L, 1)->ctypeid;
332 CType *ct = ctype_raw(cts, id);
333 cTValue *tv;
334 if (ctype_isptr(ct->info)) id = ctype_cid(ct->info);
335 tv = lj_ctype_meta(cts, id, mm);
336 if (!tv)
337 lj_err_callerv(L, LJ_ERR_FFI_BADMM, strdata(lj_ctype_repr(L, id, NULL)),
338 strdata(mmname_str(G(L), mm)));
339 return lj_meta_tailcall(L, tv);
340 }
341
LJLIB_CF(ffi_meta___pairs)342 LJLIB_CF(ffi_meta___pairs)
343 {
344 return ffi_pairs(L, MM_pairs);
345 }
346
LJLIB_CF(ffi_meta___ipairs)347 LJLIB_CF(ffi_meta___ipairs)
348 {
349 return ffi_pairs(L, MM_ipairs);
350 }
351
LJLIB_SET(__metatable)352 LJLIB_PUSH("ffi") LJLIB_SET(__metatable)
353
354 #include "lj_libdef.h"
355
356 /* -- C library metamethods ----------------------------------------------- */
357
358 #define LJLIB_MODULE_ffi_clib
359
360 /* Index C library by a name. */
361 static TValue *ffi_clib_index(lua_State *L)
362 {
363 TValue *o = L->base;
364 CLibrary *cl;
365 if (!(o < L->top && tvisudata(o) && udataV(o)->udtype == UDTYPE_FFI_CLIB))
366 lj_err_argt(L, 1, LUA_TUSERDATA);
367 cl = (CLibrary *)uddata(udataV(o));
368 if (!(o+1 < L->top && tvisstr(o+1)))
369 lj_err_argt(L, 2, LUA_TSTRING);
370 return lj_clib_index(L, cl, strV(o+1));
371 }
372
373 LJLIB_CF(ffi_clib___index) LJLIB_REC(clib_index 1)
374 {
375 TValue *tv = ffi_clib_index(L);
376 if (tviscdata(tv)) {
377 CTState *cts = ctype_cts(L);
378 GCcdata *cd = cdataV(tv);
379 CType *s = ctype_get(cts, cd->ctypeid);
380 if (ctype_isextern(s->info)) {
381 CTypeID sid = ctype_cid(s->info);
382 void *sp = *(void **)cdataptr(cd);
383 CType *ct = ctype_raw(cts, sid);
384 if (lj_cconv_tv_ct(cts, ct, sid, L->top-1, sp))
385 lj_gc_check(L);
386 return 1;
387 }
388 }
389 copyTV(L, L->top-1, tv);
390 return 1;
391 }
392
393 LJLIB_CF(ffi_clib___newindex) LJLIB_REC(clib_index 0)
394 {
395 TValue *tv = ffi_clib_index(L);
396 TValue *o = L->base+2;
397 if (o < L->top && tviscdata(tv)) {
398 CTState *cts = ctype_cts(L);
399 GCcdata *cd = cdataV(tv);
400 CType *d = ctype_get(cts, cd->ctypeid);
401 if (ctype_isextern(d->info)) {
402 CTInfo qual = 0;
403 for (;;) { /* Skip attributes and collect qualifiers. */
404 d = ctype_child(cts, d);
405 if (!ctype_isattrib(d->info)) break;
406 if (ctype_attrib(d->info) == CTA_QUAL) qual |= d->size;
407 }
408 if (!((d->info|qual) & CTF_CONST)) {
409 lj_cconv_ct_tv(cts, d, *(void **)cdataptr(cd), o, 0);
410 return 0;
411 }
412 }
413 }
414 lj_err_caller(L, LJ_ERR_FFI_WRCONST);
415 return 0; /* unreachable */
416 }
417
LJLIB_CF(ffi_clib___gc)418 LJLIB_CF(ffi_clib___gc)
419 {
420 TValue *o = L->base;
421 if (o < L->top && tvisudata(o) && udataV(o)->udtype == UDTYPE_FFI_CLIB)
422 lj_clib_unload((CLibrary *)uddata(udataV(o)));
423 return 0;
424 }
425
426 #include "lj_libdef.h"
427
428 /* -- Callback function metamethods --------------------------------------- */
429
430 #define LJLIB_MODULE_ffi_callback
431
ffi_callback_set(lua_State * L,GCfunc * fn)432 static int ffi_callback_set(lua_State *L, GCfunc *fn)
433 {
434 GCcdata *cd = ffi_checkcdata(L, 1);
435 CTState *cts = ctype_cts(L);
436 CType *ct = ctype_raw(cts, cd->ctypeid);
437 if (ctype_isptr(ct->info) && (LJ_32 || ct->size == 8)) {
438 MSize slot = lj_ccallback_ptr2slot(cts, *(void **)cdataptr(cd));
439 if (slot < cts->cb.sizeid && cts->cb.cbid[slot] != 0) {
440 GCtab *t = cts->miscmap;
441 TValue *tv = lj_tab_setint(L, t, (int32_t)slot);
442 if (fn) {
443 setfuncV(L, tv, fn);
444 lj_gc_anybarriert(L, t);
445 } else {
446 setnilV(tv);
447 cts->cb.cbid[slot] = 0;
448 cts->cb.topid = slot < cts->cb.topid ? slot : cts->cb.topid;
449 }
450 return 0;
451 }
452 }
453 lj_err_caller(L, LJ_ERR_FFI_BADCBACK);
454 return 0;
455 }
456
LJLIB_CF(ffi_callback_free)457 LJLIB_CF(ffi_callback_free)
458 {
459 return ffi_callback_set(L, NULL);
460 }
461
LJLIB_CF(ffi_callback_set)462 LJLIB_CF(ffi_callback_set)
463 {
464 GCfunc *fn = lj_lib_checkfunc(L, 2);
465 return ffi_callback_set(L, fn);
466 }
467
LJLIB_SET(__index)468 LJLIB_PUSH(top-1) LJLIB_SET(__index)
469
470 #include "lj_libdef.h"
471
472 /* -- FFI library functions ----------------------------------------------- */
473
474 #define LJLIB_MODULE_ffi
475
476 LJLIB_CF(ffi_cdef)
477 {
478 GCstr *s = lj_lib_checkstr(L, 1);
479 CPState cp;
480 int errcode;
481 cp.L = L;
482 cp.cts = ctype_cts(L);
483 cp.srcname = strdata(s);
484 cp.p = strdata(s);
485 cp.param = L->base+1;
486 cp.mode = CPARSE_MODE_MULTI|CPARSE_MODE_DIRECT;
487 errcode = lj_cparse(&cp);
488 if (errcode) lj_err_throw(L, errcode); /* Propagate errors. */
489 lj_gc_check(L);
490 return 0;
491 }
492
493 LJLIB_CF(ffi_new) LJLIB_REC(.)
494 {
495 CTState *cts = ctype_cts(L);
496 CTypeID id = ffi_checkctype(L, cts, NULL);
497 CType *ct = ctype_raw(cts, id);
498 CTSize sz;
499 CTInfo info = lj_ctype_info(cts, id, &sz);
500 TValue *o = L->base+1;
501 GCcdata *cd;
502 if ((info & CTF_VLA)) {
503 o++;
504 sz = lj_ctype_vlsize(cts, ct, (CTSize)ffi_checkint(L, 2));
505 }
506 if (sz == CTSIZE_INVALID)
507 lj_err_arg(L, 1, LJ_ERR_FFI_INVSIZE);
508 cd = lj_cdata_newx(cts, id, sz, info);
509 setcdataV(L, o-1, cd); /* Anchor the uninitialized cdata. */
510 lj_cconv_ct_init(cts, ct, sz, cdataptr(cd),
511 o, (MSize)(L->top - o)); /* Initialize cdata. */
512 if (ctype_isstruct(ct->info)) {
513 /* Handle ctype __gc metamethod. Use the fast lookup here. */
514 cTValue *tv = lj_tab_getinth(cts->miscmap, -(int32_t)id);
515 if (tv && tvistab(tv) && (tv = lj_meta_fast(L, tabV(tv), MM_gc))) {
516 GCtab *t = cts->finalizer;
517 if (gcref(t->metatable)) {
518 /* Add to finalizer table, if still enabled. */
519 copyTV(L, lj_tab_set(L, t, o-1), tv);
520 lj_gc_anybarriert(L, t);
521 cd->marked |= LJ_GC_CDATA_FIN;
522 }
523 }
524 }
525 L->top = o; /* Only return the cdata itself. */
526 lj_gc_check(L);
527 return 1;
528 }
529
LJLIB_REC(ffi_new)530 LJLIB_CF(ffi_cast) LJLIB_REC(ffi_new)
531 {
532 CTState *cts = ctype_cts(L);
533 CTypeID id = ffi_checkctype(L, cts, NULL);
534 CType *d = ctype_raw(cts, id);
535 TValue *o = lj_lib_checkany(L, 2);
536 L->top = o+1; /* Make sure this is the last item on the stack. */
537 if (!(ctype_isnum(d->info) || ctype_isptr(d->info) || ctype_isenum(d->info)))
538 lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
539 if (!(tviscdata(o) && cdataV(o)->ctypeid == id)) {
540 GCcdata *cd = lj_cdata_new(cts, id, d->size);
541 lj_cconv_ct_tv(cts, d, cdataptr(cd), o, CCF_CAST);
542 setcdataV(L, o, cd);
543 lj_gc_check(L);
544 }
545 return 1;
546 }
547
548 LJLIB_CF(ffi_typeof) LJLIB_REC(.)
549 {
550 CTState *cts = ctype_cts(L);
551 CTypeID id = ffi_checkctype(L, cts, L->base+1);
552 GCcdata *cd = lj_cdata_new(cts, CTID_CTYPEID, 4);
553 *(CTypeID *)cdataptr(cd) = id;
554 setcdataV(L, L->top-1, cd);
555 lj_gc_check(L);
556 return 1;
557 }
558
559 /* Internal and unsupported API. */
LJLIB_CF(ffi_typeinfo)560 LJLIB_CF(ffi_typeinfo)
561 {
562 CTState *cts = ctype_cts(L);
563 CTypeID id = (CTypeID)ffi_checkint(L, 1);
564 if (id > 0 && id < cts->top) {
565 CType *ct = ctype_get(cts, id);
566 GCtab *t;
567 lua_createtable(L, 0, 4); /* Increment hash size if fields are added. */
568 t = tabV(L->top-1);
569 setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "info")), (int32_t)ct->info);
570 if (ct->size != CTSIZE_INVALID)
571 setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "size")), (int32_t)ct->size);
572 if (ct->sib)
573 setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "sib")), (int32_t)ct->sib);
574 if (gcref(ct->name)) {
575 GCstr *s = gco2str(gcref(ct->name));
576 if (isdead(G(L), obj2gco(s))) flipwhite(obj2gco(s));
577 setstrV(L, lj_tab_setstr(L, t, lj_str_newlit(L, "name")), s);
578 }
579 lj_gc_check(L);
580 return 1;
581 }
582 return 0;
583 }
584
585 LJLIB_CF(ffi_istype) LJLIB_REC(.)
586 {
587 CTState *cts = ctype_cts(L);
588 CTypeID id1 = ffi_checkctype(L, cts, NULL);
589 TValue *o = lj_lib_checkany(L, 2);
590 int b = 0;
591 if (tviscdata(o)) {
592 GCcdata *cd = cdataV(o);
593 CTypeID id2 = cd->ctypeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) :
594 cd->ctypeid;
595 CType *ct1 = lj_ctype_rawref(cts, id1);
596 CType *ct2 = lj_ctype_rawref(cts, id2);
597 if (ct1 == ct2) {
598 b = 1;
599 } else if (ctype_type(ct1->info) == ctype_type(ct2->info) &&
600 ct1->size == ct2->size) {
601 if (ctype_ispointer(ct1->info))
602 b = lj_cconv_compatptr(cts, ct1, ct2, CCF_IGNQUAL);
603 else if (ctype_isnum(ct1->info) || ctype_isvoid(ct1->info))
604 b = (((ct1->info ^ ct2->info) & ~(CTF_QUAL|CTF_LONG)) == 0);
605 } else if (ctype_isstruct(ct1->info) && ctype_isptr(ct2->info) &&
606 ct1 == ctype_rawchild(cts, ct2)) {
607 b = 1;
608 }
609 }
610 setboolV(L->top-1, b);
611 setboolV(&G(L)->tmptv2, b); /* Remember for trace recorder. */
612 return 1;
613 }
614
LJLIB_REC(ffi_xof FF_ffi_sizeof)615 LJLIB_CF(ffi_sizeof) LJLIB_REC(ffi_xof FF_ffi_sizeof)
616 {
617 CTState *cts = ctype_cts(L);
618 CTypeID id = ffi_checkctype(L, cts, NULL);
619 CTSize sz;
620 if (LJ_UNLIKELY(tviscdata(L->base) && cdataisv(cdataV(L->base)))) {
621 sz = cdatavlen(cdataV(L->base));
622 } else {
623 CType *ct = lj_ctype_rawref(cts, id);
624 if (ctype_isvltype(ct->info))
625 sz = lj_ctype_vlsize(cts, ct, (CTSize)ffi_checkint(L, 2));
626 else
627 sz = ctype_hassize(ct->info) ? ct->size : CTSIZE_INVALID;
628 if (LJ_UNLIKELY(sz == CTSIZE_INVALID)) {
629 setnilV(L->top-1);
630 return 1;
631 }
632 }
633 setintV(L->top-1, (int32_t)sz);
634 return 1;
635 }
636
LJLIB_REC(ffi_xof FF_ffi_alignof)637 LJLIB_CF(ffi_alignof) LJLIB_REC(ffi_xof FF_ffi_alignof)
638 {
639 CTState *cts = ctype_cts(L);
640 CTypeID id = ffi_checkctype(L, cts, NULL);
641 CTSize sz = 0;
642 CTInfo info = lj_ctype_info(cts, id, &sz);
643 setintV(L->top-1, 1 << ctype_align(info));
644 return 1;
645 }
646
LJLIB_REC(ffi_xof FF_ffi_offsetof)647 LJLIB_CF(ffi_offsetof) LJLIB_REC(ffi_xof FF_ffi_offsetof)
648 {
649 CTState *cts = ctype_cts(L);
650 CTypeID id = ffi_checkctype(L, cts, NULL);
651 GCstr *name = lj_lib_checkstr(L, 2);
652 CType *ct = lj_ctype_rawref(cts, id);
653 CTSize ofs;
654 if (ctype_isstruct(ct->info) && ct->size != CTSIZE_INVALID) {
655 CType *fct = lj_ctype_getfield(cts, ct, name, &ofs);
656 if (fct) {
657 setintV(L->top-1, ofs);
658 if (ctype_isfield(fct->info)) {
659 return 1;
660 } else if (ctype_isbitfield(fct->info)) {
661 setintV(L->top++, ctype_bitpos(fct->info));
662 setintV(L->top++, ctype_bitbsz(fct->info));
663 return 3;
664 }
665 }
666 }
667 return 0;
668 }
669
670 LJLIB_CF(ffi_errno) LJLIB_REC(.)
671 {
672 int err = errno;
673 if (L->top > L->base)
674 errno = ffi_checkint(L, 1);
675 setintV(L->top++, err);
676 return 1;
677 }
678
679 LJLIB_CF(ffi_string) LJLIB_REC(.)
680 {
681 CTState *cts = ctype_cts(L);
682 TValue *o = lj_lib_checkany(L, 1);
683 const char *p;
684 size_t len;
685 if (o+1 < L->top && !tvisnil(o+1)) {
686 len = (size_t)ffi_checkint(L, 2);
687 lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CVOID), (uint8_t *)&p, o,
688 CCF_ARG(1));
689 } else {
690 lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CCHAR), (uint8_t *)&p, o,
691 CCF_ARG(1));
692 len = strlen(p);
693 }
694 L->top = o+1; /* Make sure this is the last item on the stack. */
695 setstrV(L, o, lj_str_new(L, p, len));
696 lj_gc_check(L);
697 return 1;
698 }
699
700 LJLIB_CF(ffi_copy) LJLIB_REC(.)
701 {
702 void *dp = ffi_checkptr(L, 1, CTID_P_VOID);
703 void *sp = ffi_checkptr(L, 2, CTID_P_CVOID);
704 TValue *o = L->base+1;
705 CTSize len;
706 if (tvisstr(o) && o+1 >= L->top)
707 len = strV(o)->len+1; /* Copy Lua string including trailing '\0'. */
708 else
709 len = (CTSize)ffi_checkint(L, 3);
710 memcpy(dp, sp, len);
711 return 0;
712 }
713
714 LJLIB_CF(ffi_fill) LJLIB_REC(.)
715 {
716 void *dp = ffi_checkptr(L, 1, CTID_P_VOID);
717 CTSize len = (CTSize)ffi_checkint(L, 2);
718 int32_t fill = 0;
719 if (L->base+2 < L->top && !tvisnil(L->base+2)) fill = ffi_checkint(L, 3);
720 memset(dp, fill, len);
721 return 0;
722 }
723
724 /* Test ABI string. */
725 LJLIB_CF(ffi_abi) LJLIB_REC(.)
726 {
727 GCstr *s = lj_lib_checkstr(L, 1);
728 int b = lj_cparse_case(s,
729 #if LJ_64
730 "\00564bit"
731 #else
732 "\00532bit"
733 #endif
734 #if LJ_ARCH_HASFPU
735 "\003fpu"
736 #endif
737 #if LJ_ABI_SOFTFP
738 "\006softfp"
739 #else
740 "\006hardfp"
741 #endif
742 #if LJ_ABI_EABI
743 "\004eabi"
744 #endif
745 #if LJ_ABI_WIN
746 "\003win"
747 #endif
748 #if LJ_TARGET_UWP
749 "\003uwp"
750 #endif
751 #if LJ_LE
752 "\002le"
753 #else
754 "\002be"
755 #endif
756 #if LJ_GC64
757 "\004gc64"
758 #endif
759 ) >= 0;
760 setboolV(L->top-1, b);
761 setboolV(&G(L)->tmptv2, b); /* Remember for trace recorder. */
762 return 1;
763 }
764
765 LJLIB_PUSH(top-8) LJLIB_SET(!) /* Store reference to miscmap table. */
766
LJLIB_CF(ffi_metatype)767 LJLIB_CF(ffi_metatype)
768 {
769 CTState *cts = ctype_cts(L);
770 CTypeID id = ffi_checkctype(L, cts, NULL);
771 GCtab *mt = lj_lib_checktab(L, 2);
772 GCtab *t = cts->miscmap;
773 CType *ct = ctype_get(cts, id); /* Only allow raw types. */
774 TValue *tv;
775 GCcdata *cd;
776 if (!(ctype_isstruct(ct->info) || ctype_iscomplex(ct->info) ||
777 ctype_isvector(ct->info)))
778 lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
779 tv = lj_tab_setinth(L, t, -(int32_t)id);
780 if (!tvisnil(tv))
781 lj_err_caller(L, LJ_ERR_PROTMT);
782 settabV(L, tv, mt);
783 lj_gc_anybarriert(L, t);
784 cd = lj_cdata_new(cts, CTID_CTYPEID, 4);
785 *(CTypeID *)cdataptr(cd) = id;
786 setcdataV(L, L->top-1, cd);
787 lj_gc_check(L);
788 return 1;
789 }
790
791 LJLIB_PUSH(top-7) LJLIB_SET(!) /* Store reference to finalizer table. */
792
LJLIB_CF(ffi_gc)793 LJLIB_CF(ffi_gc) LJLIB_REC(.)
794 {
795 GCcdata *cd = ffi_checkcdata(L, 1);
796 TValue *fin = lj_lib_checkany(L, 2);
797 CTState *cts = ctype_cts(L);
798 CType *ct = ctype_raw(cts, cd->ctypeid);
799 if (!(ctype_isptr(ct->info) || ctype_isstruct(ct->info) ||
800 ctype_isrefarray(ct->info)))
801 lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
802 lj_cdata_setfin(L, cd, gcval(fin), itype(fin));
803 L->top = L->base+1; /* Pass through the cdata object. */
804 return 1;
805 }
806
807 LJLIB_PUSH(top-5) LJLIB_SET(!) /* Store clib metatable in func environment. */
808
LJLIB_CF(ffi_load)809 LJLIB_CF(ffi_load)
810 {
811 GCstr *name = lj_lib_checkstr(L, 1);
812 int global = (L->base+1 < L->top && tvistruecond(L->base+1));
813 lj_clib_load(L, tabref(curr_func(L)->c.env), name, global);
814 return 1;
815 }
816
LJLIB_SET(C)817 LJLIB_PUSH(top-4) LJLIB_SET(C)
818 LJLIB_PUSH(top-3) LJLIB_SET(os)
819 LJLIB_PUSH(top-2) LJLIB_SET(arch)
820
821 #include "lj_libdef.h"
822
823 /* ------------------------------------------------------------------------ */
824
825 /* Create special weak-keyed finalizer table. */
826 static GCtab *ffi_finalizer(lua_State *L)
827 {
828 /* NOBARRIER: The table is new (marked white). */
829 GCtab *t = lj_tab_new(L, 0, 1);
830 settabV(L, L->top++, t);
831 setgcref(t->metatable, obj2gco(t));
832 setstrV(L, lj_tab_setstr(L, t, lj_str_newlit(L, "__mode")),
833 lj_str_newlit(L, "k"));
834 t->nomm = (uint8_t)(~(1u<<MM_mode));
835 return t;
836 }
837
838 /* Register FFI module as loaded. */
ffi_register_module(lua_State * L)839 static void ffi_register_module(lua_State *L)
840 {
841 cTValue *tmp = lj_tab_getstr(tabV(registry(L)), lj_str_newlit(L, "_LOADED"));
842 if (tmp && tvistab(tmp)) {
843 GCtab *t = tabV(tmp);
844 copyTV(L, lj_tab_setstr(L, t, lj_str_newlit(L, LUA_FFILIBNAME)), L->top-1);
845 lj_gc_anybarriert(L, t);
846 }
847 }
848
luaopen_ffi(lua_State * L)849 LUALIB_API int luaopen_ffi(lua_State *L)
850 {
851 CTState *cts = lj_ctype_init(L);
852 settabV(L, L->top++, (cts->miscmap = lj_tab_new(L, 0, 1)));
853 cts->finalizer = ffi_finalizer(L);
854 LJ_LIB_REG(L, NULL, ffi_meta);
855 /* NOBARRIER: basemt is a GC root. */
856 setgcref(basemt_it(G(L), LJ_TCDATA), obj2gco(tabV(L->top-1)));
857 LJ_LIB_REG(L, NULL, ffi_clib);
858 LJ_LIB_REG(L, NULL, ffi_callback);
859 /* NOBARRIER: the key is new and lj_tab_newkey() handles the barrier. */
860 settabV(L, lj_tab_setstr(L, cts->miscmap, &cts->g->strempty), tabV(L->top-1));
861 L->top--;
862 lj_clib_default(L, tabV(L->top-1)); /* Create ffi.C default namespace. */
863 lua_pushliteral(L, LJ_OS_NAME);
864 lua_pushliteral(L, LJ_ARCH_NAME);
865 LJ_LIB_REG(L, NULL, ffi); /* Note: no global "ffi" created! */
866 ffi_register_module(L);
867 return 1;
868 }
869
870 #endif
871