1/*
2** C type conversions.
3** Copyright (C) 2005-2014 Mike Pall. See Copyright Notice in luajit.h
4*/
5
6#include "lj_obj.h"
7
8#if LJ_HASFFI
9
10#include "lj_err.h"
11#include "lj_tab.h"
12#include "lj_ctype.h"
13#include "lj_cdata.h"
14#include "lj_cconv.h"
15#include "lj_ccallback.h"
16
17/* -- Conversion errors --------------------------------------------------- */
18
19/* Bad conversion. */
20LJ_NORET static void cconv_err_conv(CTState *cts, CType *d, CType *s,
21 CTInfo flags)
22{
23 const char *dst = strdata(lj_ctype_repr(cts->L, ctype_typeid(cts, d), NULL));
24 const char *src;
25 if ((flags & CCF_FROMTV))
26 src = lj_obj_typename[1+(ctype_isnum(s->info) ? LUA_TNUMBER :
27 ctype_isarray(s->info) ? LUA_TSTRING : LUA_TNIL)];
28 else
29 src = strdata(lj_ctype_repr(cts->L, ctype_typeid(cts, s), NULL));
30 if (CCF_GETARG(flags))
31 lj_err_argv(cts->L, CCF_GETARG(flags), LJ_ERR_FFI_BADCONV, src, dst);
32 else
33 lj_err_callerv(cts->L, LJ_ERR_FFI_BADCONV, src, dst);
34}
35
36/* Bad conversion from TValue. */
37LJ_NORET static void cconv_err_convtv(CTState *cts, CType *d, TValue *o,
38 CTInfo flags)
39{
40 const char *dst = strdata(lj_ctype_repr(cts->L, ctype_typeid(cts, d), NULL));
41 const char *src = lj_typename(o);
42 if (CCF_GETARG(flags))
43 lj_err_argv(cts->L, CCF_GETARG(flags), LJ_ERR_FFI_BADCONV, src, dst);
44 else
45 lj_err_callerv(cts->L, LJ_ERR_FFI_BADCONV, src, dst);
46}
47
48/* Initializer overflow. */
49LJ_NORET static void cconv_err_initov(CTState *cts, CType *d)
50{
51 const char *dst = strdata(lj_ctype_repr(cts->L, ctype_typeid(cts, d), NULL));
52 lj_err_callerv(cts->L, LJ_ERR_FFI_INITOV, dst);
53}
54
55/* -- C type compatibility checks ----------------------------------------- */
56
57/* Get raw type and qualifiers for a child type. Resolves enums, too. */
58static CType *cconv_childqual(CTState *cts, CType *ct, CTInfo *qual)
59{
60 ct = ctype_child(cts, ct);
61 for (;;) {
62 if (ctype_isattrib(ct->info)) {
63 if (ctype_attrib(ct->info) == CTA_QUAL) *qual |= ct->size;
64 } else if (!ctype_isenum(ct->info)) {
65 break;
66 }
67 ct = ctype_child(cts, ct);
68 }
69 *qual |= (ct->info & CTF_QUAL);
70 return ct;
71}
72
73/* Check for compatible types when converting to a pointer.
74** Note: these checks are more relaxed than what C99 mandates.
75*/
76int lj_cconv_compatptr(CTState *cts, CType *d, CType *s, CTInfo flags)
77{
78 if (!((flags & CCF_CAST) || d == s)) {
79 CTInfo dqual = 0, squal = 0;
80 d = cconv_childqual(cts, d, &dqual);
81 if (!ctype_isstruct(s->info))
82 s = cconv_childqual(cts, s, &squal);
83 if ((flags & CCF_SAME)) {
84 if (dqual != squal)
85 return 0; /* Different qualifiers. */
86 } else if (!(flags & CCF_IGNQUAL)) {
87 if ((dqual & squal) != squal)
88 return 0; /* Discarded qualifiers. */
89 if (ctype_isvoid(d->info) || ctype_isvoid(s->info))
90 return 1; /* Converting to/from void * is always ok. */
91 }
92 if (ctype_type(d->info) != ctype_type(s->info) ||
93 d->size != s->size)
94 return 0; /* Different type or different size. */
95 if (ctype_isnum(d->info)) {
96 if (((d->info ^ s->info) & (CTF_BOOL|CTF_FP)))
97 return 0; /* Different numeric types. */
98 } else if (ctype_ispointer(d->info)) {
99 /* Check child types for compatibility. */
100 return lj_cconv_compatptr(cts, d, s, flags|CCF_SAME);
101 } else if (ctype_isstruct(d->info)) {
102 if (d != s)
103 return 0; /* Must be exact same type for struct/union. */
104 } else if (ctype_isfunc(d->info)) {
105 /* NYI: structural equality of functions. */
106 }
107 }
108 return 1; /* Types are compatible. */
109}
110
111/* -- C type to C type conversion ----------------------------------------- */
112
113/* Convert C type to C type. Caveat: expects to get the raw CType!
114**
115** Note: This is only used by the interpreter and not optimized at all.
116** The JIT compiler will do a much better job specializing for each case.
117*/
118void lj_cconv_ct_ct(CTState *cts, CType *d, CType *s,
119 uint8_t *dp, uint8_t *sp, CTInfo flags)
120{
121 CTSize dsize = d->size, ssize = s->size;
122 CTInfo dinfo = d->info, sinfo = s->info;
123 void *tmpptr;
124
125 lua_assert(!ctype_isenum(dinfo) && !ctype_isenum(sinfo));
126 lua_assert(!ctype_isattrib(dinfo) && !ctype_isattrib(sinfo));
127
128 if (ctype_type(dinfo) > CT_MAYCONVERT || ctype_type(sinfo) > CT_MAYCONVERT)
129 goto err_conv;
130
131 /* Some basic sanity checks. */
132 lua_assert(!ctype_isnum(dinfo) || dsize > 0);
133 lua_assert(!ctype_isnum(sinfo) || ssize > 0);
134 lua_assert(!ctype_isbool(dinfo) || dsize == 1 || dsize == 4);
135 lua_assert(!ctype_isbool(sinfo) || ssize == 1 || ssize == 4);
136 lua_assert(!ctype_isinteger(dinfo) || (1u<<lj_fls(dsize)) == dsize);
137 lua_assert(!ctype_isinteger(sinfo) || (1u<<lj_fls(ssize)) == ssize);
138
139 switch (cconv_idx2(dinfo, sinfo)) {
140 /* Destination is a bool. */
141 case CCX(B, B):
142 /* Source operand is already normalized. */
143 if (dsize == 1) *dp = *sp; else *(int *)dp = *sp;
144 break;
145 case CCX(B, I): {
146 MSize i;
147 uint8_t b = 0;
148 for (i = 0; i < ssize; i++) b |= sp[i];
149 b = (b != 0);
150 if (dsize == 1) *dp = b; else *(int *)dp = b;
151 break;
152 }
153 case CCX(B, F): {
154 uint8_t b;
155 if (ssize == sizeof(double)) b = (*(double *)sp != 0);
156 else if (ssize == sizeof(float)) b = (*(float *)sp != 0);
157 else goto err_conv; /* NYI: long double. */
158 if (dsize == 1) *dp = b; else *(int *)dp = b;
159 break;
160 }
161
162 /* Destination is an integer. */
163 case CCX(I, B):
164 case CCX(I, I):
165 conv_I_I:
166 if (dsize > ssize) { /* Zero-extend or sign-extend LSB. */
167#if LJ_LE
168 uint8_t fill = (!(sinfo & CTF_UNSIGNED) && (sp[ssize-1]&0x80)) ? 0xff : 0;
169 memcpy(dp, sp, ssize);
170 memset(dp + ssize, fill, dsize-ssize);
171#else
172 uint8_t fill = (!(sinfo & CTF_UNSIGNED) && (sp[0]&0x80)) ? 0xff : 0;
173 memset(dp, fill, dsize-ssize);
174 memcpy(dp + (dsize-ssize), sp, ssize);
175#endif
176 } else { /* Copy LSB. */
177#if LJ_LE
178 memcpy(dp, sp, dsize);
179#else
180 memcpy(dp, sp + (ssize-dsize), dsize);
181#endif
182 }
183 break;
184 case CCX(I, F): {
185 double n; /* Always convert via double. */
186 conv_I_F:
187 /* Convert source to double. */
188 if (ssize == sizeof(double)) n = *(double *)sp;
189 else if (ssize == sizeof(float)) n = (double)*(float *)sp;
190 else goto err_conv; /* NYI: long double. */
191 /* Then convert double to integer. */
192 /* The conversion must exactly match the semantics of JIT-compiled code! */
193 if (dsize < 4 || (dsize == 4 && !(dinfo & CTF_UNSIGNED))) {
194 int32_t i = (int32_t)n;
195 if (dsize == 4) *(int32_t *)dp = i;
196 else if (dsize == 2) *(int16_t *)dp = (int16_t)i;
197 else *(int8_t *)dp = (int8_t)i;
198 } else if (dsize == 4) {
199 *(uint32_t *)dp = (uint32_t)n;
200 } else if (dsize == 8) {
201 if (!(dinfo & CTF_UNSIGNED))
202 *(int64_t *)dp = (int64_t)n;
203 else
204 *(uint64_t *)dp = lj_num2u64(n);
205 } else {
206 goto err_conv; /* NYI: conversion to >64 bit integers. */
207 }
208 break;
209 }
210 case CCX(I, C):
211 s = ctype_child(cts, s);
212 sinfo = s->info;
213 ssize = s->size;
214 goto conv_I_F; /* Just convert re. */
215 case CCX(I, P):
216 if (!(flags & CCF_CAST)) goto err_conv;
217 sinfo = CTINFO(CT_NUM, CTF_UNSIGNED);
218 goto conv_I_I;
219 case CCX(I, A):
220 if (!(flags & CCF_CAST)) goto err_conv;
221 sinfo = CTINFO(CT_NUM, CTF_UNSIGNED);
222 ssize = CTSIZE_PTR;
223 tmpptr = sp;
224 sp = (uint8_t *)&tmpptr;
225 goto conv_I_I;
226
227 /* Destination is a floating-point number. */
228 case CCX(F, B):
229 case CCX(F, I): {
230 double n; /* Always convert via double. */
231 conv_F_I:
232 /* First convert source to double. */
233 /* The conversion must exactly match the semantics of JIT-compiled code! */
234 if (ssize < 4 || (ssize == 4 && !(sinfo & CTF_UNSIGNED))) {
235 int32_t i;
236 if (ssize == 4) {
237 i = *(int32_t *)sp;
238 } else if (!(sinfo & CTF_UNSIGNED)) {
239 if (ssize == 2) i = *(int16_t *)sp;
240 else i = *(int8_t *)sp;
241 } else {
242 if (ssize == 2) i = *(uint16_t *)sp;
243 else i = *(uint8_t *)sp;
244 }
245 n = (double)i;
246 } else if (ssize == 4) {
247 n = (double)*(uint32_t *)sp;
248 } else if (ssize == 8) {
249 if (!(sinfo & CTF_UNSIGNED)) n = (double)*(int64_t *)sp;
250 else n = (double)*(uint64_t *)sp;
251 } else {
252 goto err_conv; /* NYI: conversion from >64 bit integers. */
253 }
254 /* Convert double to destination. */
255 if (dsize == sizeof(double)) *(double *)dp = n;
256 else if (dsize == sizeof(float)) *(float *)dp = (float)n;
257 else goto err_conv; /* NYI: long double. */
258 break;
259 }
260 case CCX(F, F): {
261 double n; /* Always convert via double. */
262 conv_F_F:
263 if (ssize == dsize) goto copyval;
264 /* Convert source to double. */
265 if (ssize == sizeof(double)) n = *(double *)sp;
266 else if (ssize == sizeof(float)) n = (double)*(float *)sp;
267 else goto err_conv; /* NYI: long double. */
268 /* Convert double to destination. */
269 if (dsize == sizeof(double)) *(double *)dp = n;
270 else if (dsize == sizeof(float)) *(float *)dp = (float)n;
271 else goto err_conv; /* NYI: long double. */
272 break;
273 }
274 case CCX(F, C):
275 s = ctype_child(cts, s);
276 sinfo = s->info;
277 ssize = s->size;
278 goto conv_F_F; /* Ignore im, and convert from re. */
279
280 /* Destination is a complex number. */
281 case CCX(C, I):
282 d = ctype_child(cts, d);
283 dinfo = d->info;
284 dsize = d->size;
285 memset(dp + dsize, 0, dsize); /* Clear im. */
286 goto conv_F_I; /* Convert to re. */
287 case CCX(C, F):
288 d = ctype_child(cts, d);
289 dinfo = d->info;
290 dsize = d->size;
291 memset(dp + dsize, 0, dsize); /* Clear im. */
292 goto conv_F_F; /* Convert to re. */
293
294 case CCX(C, C):
295 if (dsize != ssize) { /* Different types: convert re/im separately. */
296 CType *dc = ctype_child(cts, d);
297 CType *sc = ctype_child(cts, s);
298 lj_cconv_ct_ct(cts, dc, sc, dp, sp, flags);
299 lj_cconv_ct_ct(cts, dc, sc, dp + dc->size, sp + sc->size, flags);
300 return;
301 }
302 goto copyval; /* Otherwise this is easy. */
303
304 /* Destination is a vector. */
305 case CCX(V, I):
306 case CCX(V, F):
307 case CCX(V, C): {
308 CType *dc = ctype_child(cts, d);
309 CTSize esize;
310 /* First convert the scalar to the first element. */
311 lj_cconv_ct_ct(cts, dc, s, dp, sp, flags);
312 /* Then replicate it to the other elements (splat). */
313 for (sp = dp, esize = dc->size; dsize > esize; dsize -= esize) {
314 dp += esize;
315 memcpy(dp, sp, esize);
316 }
317 break;
318 }
319
320 case CCX(V, V):
321 /* Copy same-sized vectors, even for different lengths/element-types. */
322 if (dsize != ssize) goto err_conv;
323 goto copyval;
324
325 /* Destination is a pointer. */
326 case CCX(P, I):
327 if (!(flags & CCF_CAST)) goto err_conv;
328 dinfo = CTINFO(CT_NUM, CTF_UNSIGNED);
329 goto conv_I_I;
330
331 case CCX(P, F):
332 if (!(flags & CCF_CAST) || !(flags & CCF_FROMTV)) goto err_conv;
333 /* The signed conversion is cheaper. x64 really has 47 bit pointers. */
334 dinfo = CTINFO(CT_NUM, (LJ_64 && dsize == 8) ? 0 : CTF_UNSIGNED);
335 goto conv_I_F;
336
337 case CCX(P, P):
338 if (!lj_cconv_compatptr(cts, d, s, flags)) goto err_conv;
339 cdata_setptr(dp, dsize, cdata_getptr(sp, ssize));
340 break;
341
342 case CCX(P, A):
343 case CCX(P, S):
344 if (!lj_cconv_compatptr(cts, d, s, flags)) goto err_conv;
345 cdata_setptr(dp, dsize, sp);
346 break;
347
348 /* Destination is an array. */
349 case CCX(A, A):
350 if ((flags & CCF_CAST) || (d->info & CTF_VLA) || dsize != ssize ||
351 d->size == CTSIZE_INVALID || !lj_cconv_compatptr(cts, d, s, flags))
352 goto err_conv;
353 goto copyval;
354
355 /* Destination is a struct/union. */
356 case CCX(S, S):
357 if ((flags & CCF_CAST) || (d->info & CTF_VLA) || d != s)
358 goto err_conv; /* Must be exact same type. */
359copyval: /* Copy value. */
360 lua_assert(dsize == ssize);
361 memcpy(dp, sp, dsize);
362 break;
363
364 default:
365 err_conv:
366 cconv_err_conv(cts, d, s, flags);
367 }
368}
369
370/* -- C type to TValue conversion ----------------------------------------- */
371
372/* Convert C type to TValue. Caveat: expects to get the raw CType! */
373int lj_cconv_tv_ct(CTState *cts, CType *s, CTypeID sid,
374 TValue *o, uint8_t *sp)
375{
376 CTInfo sinfo = s->info;
377 if (ctype_isnum(sinfo)) {
378 if (!ctype_isbool(sinfo)) {
379 if (ctype_isinteger(sinfo) && s->size > 4) goto copyval;
380 if (LJ_DUALNUM && ctype_isinteger(sinfo)) {
381 int32_t i;
382 lj_cconv_ct_ct(cts, ctype_get(cts, CTID_INT32), s,
383 (uint8_t *)&i, sp, 0);
384 if ((sinfo & CTF_UNSIGNED) && i < 0)
385 setnumV(o, (lua_Number)(uint32_t)i);
386 else
387 setintV(o, i);
388 } else {
389 lj_cconv_ct_ct(cts, ctype_get(cts, CTID_DOUBLE), s,
390 (uint8_t *)&o->n, sp, 0);
391 /* Numbers are NOT canonicalized here! Beware of uninitialized data. */
392 lua_assert(tvisnum(o));
393 }
394 } else {
395 uint32_t b = s->size == 1 ? (*sp != 0) : (*(int *)sp != 0);
396 setboolV(o, b);
397 setboolV(&cts->g->tmptv2, b); /* Remember for trace recorder. */
398 }
399 return 0;
400 } else if (ctype_isrefarray(sinfo) || ctype_isstruct(sinfo)) {
401 /* Create reference. */
402 setcdataV(cts->L, o, lj_cdata_newref(cts, sp, sid));
403 return 1; /* Need GC step. */
404 } else {
405 GCcdata *cd;
406 CTSize sz;
407 copyval: /* Copy value. */
408 sz = s->size;
409 lua_assert(sz != CTSIZE_INVALID);
410 /* Attributes are stripped, qualifiers are kept (but mostly ignored). */
411 cd = lj_cdata_new(cts, ctype_typeid(cts, s), sz);
412 setcdataV(cts->L, o, cd);
413 memcpy(cdataptr(cd), sp, sz);
414 return 1; /* Need GC step. */
415 }
416}
417
418/* Convert bitfield to TValue. */
419int lj_cconv_tv_bf(CTState *cts, CType *s, TValue *o, uint8_t *sp)
420{
421 CTInfo info = s->info;
422 CTSize pos, bsz;
423 uint32_t val;
424 lua_assert(ctype_isbitfield(info));
425 /* NYI: packed bitfields may cause misaligned reads. */
426 switch (ctype_bitcsz(info)) {
427 case 4: val = *(uint32_t *)sp; break;
428 case 2: val = *(uint16_t *)sp; break;
429 case 1: val = *(uint8_t *)sp; break;
430 default: lua_assert(0); val = 0; break;
431 }
432 /* Check if a packed bitfield crosses a container boundary. */
433 pos = ctype_bitpos(info);
434 bsz = ctype_bitbsz(info);
435 lua_assert(pos < 8*ctype_bitcsz(info));
436 lua_assert(bsz > 0 && bsz <= 8*ctype_bitcsz(info));
437 if (pos + bsz > 8*ctype_bitcsz(info))
438 lj_err_caller(cts->L, LJ_ERR_FFI_NYIPACKBIT);
439 if (!(info & CTF_BOOL)) {
440 CTSize shift = 32 - bsz;
441 if (!(info & CTF_UNSIGNED)) {
442 setintV(o, (int32_t)(val << (shift-pos)) >> shift);
443 } else {
444 val = (val << (shift-pos)) >> shift;
445 if (!LJ_DUALNUM || (int32_t)val < 0)
446 setnumV(o, (lua_Number)(uint32_t)val);
447 else
448 setintV(o, (int32_t)val);
449 }
450 } else {
451 lua_assert(bsz == 1);
452 setboolV(o, (val >> pos) & 1);
453 }
454 return 0; /* No GC step needed. */
455}
456
457/* -- TValue to C type conversion ----------------------------------------- */
458
459/* Convert table to array. */
460static void cconv_array_tab(CTState *cts, CType *d,
461 uint8_t *dp, GCtab *t, CTInfo flags)
462{
463 int32_t i;
464 CType *dc = ctype_rawchild(cts, d); /* Array element type. */
465 CTSize size = d->size, esize = dc->size, ofs = 0;
466 for (i = 0; ; i++) {
467 TValue *tv = (TValue *)lj_tab_getint(t, i);
468 if (!tv || tvisnil(tv)) {
469 if (i == 0) continue; /* Try again for 1-based tables. */
470 break; /* Stop at first nil. */
471 }
472 if (ofs >= size)
473 cconv_err_initov(cts, d);
474 lj_cconv_ct_tv(cts, dc, dp + ofs, tv, flags);
475 ofs += esize;
476 }
477 if (size != CTSIZE_INVALID) { /* Only fill up arrays with known size. */
478 if (ofs == esize) { /* Replicate a single element. */
479 for (; ofs < size; ofs += esize) memcpy(dp + ofs, dp, esize);
480 } else { /* Otherwise fill the remainder with zero. */
481 memset(dp + ofs, 0, size - ofs);
482 }
483 }
484}
485
486/* Convert table to sub-struct/union. */
487static void cconv_substruct_tab(CTState *cts, CType *d, uint8_t *dp,
488 GCtab *t, int32_t *ip, CTInfo flags)
489{
490 CTypeID id = d->sib;
491 while (id) {
492 CType *df = ctype_get(cts, id);
493 id = df->sib;
494 if (ctype_isfield(df->info) || ctype_isbitfield(df->info)) {
495 TValue *tv;
496 int32_t i = *ip, iz = i;
497 if (!gcref(df->name)) continue; /* Ignore unnamed fields. */
498 if (i >= 0) {
499 retry:
500 tv = (TValue *)lj_tab_getint(t, i);
501 if (!tv || tvisnil(tv)) {
502 if (i == 0) { i = 1; goto retry; } /* 1-based tables. */
503 if (iz == 0) { *ip = i = -1; goto tryname; } /* Init named fields. */
504 break; /* Stop at first nil. */
505 }
506 *ip = i + 1;
507 } else {
508 tryname:
509 tv = (TValue *)lj_tab_getstr(t, gco2str(gcref(df->name)));
510 if (!tv || tvisnil(tv)) continue;
511 }
512 if (ctype_isfield(df->info))
513 lj_cconv_ct_tv(cts, ctype_rawchild(cts, df), dp+df->size, tv, flags);
514 else
515 lj_cconv_bf_tv(cts, df, dp+df->size, tv);
516 if ((d->info & CTF_UNION)) break;
517 } else if (ctype_isxattrib(df->info, CTA_SUBTYPE)) {
518 cconv_substruct_tab(cts, ctype_rawchild(cts, df),
519 dp+df->size, t, ip, flags);
520 } /* Ignore all other entries in the chain. */
521 }
522}
523
524/* Convert table to struct/union. */
525static void cconv_struct_tab(CTState *cts, CType *d,
526 uint8_t *dp, GCtab *t, CTInfo flags)
527{
528 int32_t i = 0;
529 memset(dp, 0, d->size); /* Much simpler to clear the struct first. */
530 cconv_substruct_tab(cts, d, dp, t, &i, flags);
531}
532
533/* Convert TValue to C type. Caveat: expects to get the raw CType! */
534void lj_cconv_ct_tv(CTState *cts, CType *d,
535 uint8_t *dp, TValue *o, CTInfo flags)
536{
537 CTypeID sid = CTID_P_VOID;
538 CType *s;
539 void *tmpptr;
540 uint8_t tmpbool, *sp = (uint8_t *)&tmpptr;
541 if (LJ_LIKELY(tvisint(o))) {
542 sp = (uint8_t *)&o->i;
543 sid = CTID_INT32;
544 flags |= CCF_FROMTV;
545 } else if (LJ_LIKELY(tvisnum(o))) {
546 sp = (uint8_t *)&o->n;
547 sid = CTID_DOUBLE;
548 flags |= CCF_FROMTV;
549 } else if (tviscdata(o)) {
550 sp = cdataptr(cdataV(o));
551 sid = cdataV(o)->ctypeid;
552 s = ctype_get(cts, sid);
553 if (ctype_isref(s->info)) { /* Resolve reference for value. */
554 lua_assert(s->size == CTSIZE_PTR);
555 sp = *(void **)sp;
556 sid = ctype_cid(s->info);
557 }
558 s = ctype_raw(cts, sid);
559 if (ctype_isfunc(s->info)) {
560 sid = lj_ctype_intern(cts, CTINFO(CT_PTR, CTALIGN_PTR|sid), CTSIZE_PTR);
561 } else {
562 if (ctype_isenum(s->info)) s = ctype_child(cts, s);
563 goto doconv;
564 }
565 } else if (tvisstr(o)) {
566 GCstr *str = strV(o);
567 if (ctype_isenum(d->info)) { /* Match string against enum constant. */
568 CTSize ofs;
569 CType *cct = lj_ctype_getfield(cts, d, str, &ofs);
570 if (!cct || !ctype_isconstval(cct->info))
571 goto err_conv;
572 lua_assert(d->size == 4);
573 sp = (uint8_t *)&cct->size;
574 sid = ctype_cid(cct->info);
575 } else if (ctype_isrefarray(d->info)) { /* Copy string to array. */
576 CType *dc = ctype_rawchild(cts, d);
577 CTSize sz = str->len+1;
578 if (!ctype_isinteger(dc->info) || dc->size != 1)
579 goto err_conv;
580 if (d->size != 0 && d->size < sz)
581 sz = d->size;
582 memcpy(dp, strdata(str), sz);
583 return;
584 } else { /* Otherwise pass it as a const char[]. */
585 sp = (uint8_t *)strdata(str);
586 sid = CTID_A_CCHAR;
587 flags |= CCF_FROMTV;
588 }
589 } else if (tvistab(o)) {
590 if (ctype_isarray(d->info)) {
591 cconv_array_tab(cts, d, dp, tabV(o), flags);
592 return;
593 } else if (ctype_isstruct(d->info)) {
594 cconv_struct_tab(cts, d, dp, tabV(o), flags);
595 return;
596 } else {
597 goto err_conv;
598 }
599 } else if (tvisbool(o)) {
600 tmpbool = boolV(o);
601 sp = &tmpbool;
602 sid = CTID_BOOL;
603 } else if (tvisnil(o)) {
604 tmpptr = (void *)0;
605 flags |= CCF_FROMTV;
606 } else if (tvisudata(o)) {
607 GCudata *ud = udataV(o);
608 tmpptr = uddata(ud);
609 if (ud->udtype == UDTYPE_IO_FILE)
610 tmpptr = *(void **)tmpptr;
611 } else if (tvislightud(o)) {
612 tmpptr = lightudV(o);
613 } else if (tvisfunc(o)) {
614 void *p = lj_ccallback_new(cts, d, funcV(o));
615 if (p) {
616 *(void **)dp = p;
617 return;
618 }
619 goto err_conv;
620 } else {
621 err_conv:
622 cconv_err_convtv(cts, d, o, flags);
623 }
624 s = ctype_get(cts, sid);
625doconv:
626 if (ctype_isenum(d->info)) d = ctype_child(cts, d);
627 lj_cconv_ct_ct(cts, d, s, dp, sp, flags);
628}
629
630/* Convert TValue to bitfield. */
631void lj_cconv_bf_tv(CTState *cts, CType *d, uint8_t *dp, TValue *o)
632{
633 CTInfo info = d->info;
634 CTSize pos, bsz;
635 uint32_t val, mask;
636 lua_assert(ctype_isbitfield(info));
637 if ((info & CTF_BOOL)) {
638 uint8_t tmpbool;
639 lua_assert(ctype_bitbsz(info) == 1);
640 lj_cconv_ct_tv(cts, ctype_get(cts, CTID_BOOL), &tmpbool, o, 0);
641 val = tmpbool;
642 } else {
643 CTypeID did = (info & CTF_UNSIGNED) ? CTID_UINT32 : CTID_INT32;
644 lj_cconv_ct_tv(cts, ctype_get(cts, did), (uint8_t *)&val, o, 0);
645 }
646 pos = ctype_bitpos(info);
647 bsz = ctype_bitbsz(info);
648 lua_assert(pos < 8*ctype_bitcsz(info));
649 lua_assert(bsz > 0 && bsz <= 8*ctype_bitcsz(info));
650 /* Check if a packed bitfield crosses a container boundary. */
651 if (pos + bsz > 8*ctype_bitcsz(info))
652 lj_err_caller(cts->L, LJ_ERR_FFI_NYIPACKBIT);
653 mask = ((1u << bsz) - 1u) << pos;
654 val = (val << pos) & mask;
655 /* NYI: packed bitfields may cause misaligned reads/writes. */
656 switch (ctype_bitcsz(info)) {
657 case 4: *(uint32_t *)dp = (*(uint32_t *)dp & ~mask) | (uint32_t)val; break;
658 case 2: *(uint16_t *)dp = (*(uint16_t *)dp & ~mask) | (uint16_t)val; break;
659 case 1: *(uint8_t *)dp = (*(uint8_t *)dp & ~mask) | (uint8_t)val; break;
660 default: lua_assert(0); break;
661 }
662}
663
664/* -- Initialize C type with TValues -------------------------------------- */
665
666/* Initialize an array with TValues. */
667static void cconv_array_init(CTState *cts, CType *d, CTSize sz, uint8_t *dp,
668 TValue *o, MSize len)
669{
670 CType *dc = ctype_rawchild(cts, d); /* Array element type. */
671 CTSize ofs, esize = dc->size;
672 MSize i;
673 if (len*esize > sz)
674 cconv_err_initov(cts, d);
675 for (i = 0, ofs = 0; i < len; i++, ofs += esize)
676 lj_cconv_ct_tv(cts, dc, dp + ofs, o + i, 0);
677 if (ofs == esize) { /* Replicate a single element. */
678 for (; ofs < sz; ofs += esize) memcpy(dp + ofs, dp, esize);
679 } else { /* Otherwise fill the remainder with zero. */
680 memset(dp + ofs, 0, sz - ofs);
681 }
682}
683
684/* Initialize a sub-struct/union with TValues. */
685static void cconv_substruct_init(CTState *cts, CType *d, uint8_t *dp,
686 TValue *o, MSize len, MSize *ip)
687{
688 CTypeID id = d->sib;
689 while (id) {
690 CType *df = ctype_get(cts, id);
691 id = df->sib;
692 if (ctype_isfield(df->info) || ctype_isbitfield(df->info)) {
693 MSize i = *ip;
694 if (!gcref(df->name)) continue; /* Ignore unnamed fields. */
695 if (i >= len) break;
696 *ip = i + 1;
697 if (ctype_isfield(df->info))
698 lj_cconv_ct_tv(cts, ctype_rawchild(cts, df), dp+df->size, o + i, 0);
699 else
700 lj_cconv_bf_tv(cts, df, dp+df->size, o + i);
701 if ((d->info & CTF_UNION)) break;
702 } else if (ctype_isxattrib(df->info, CTA_SUBTYPE)) {
703 cconv_substruct_init(cts, ctype_rawchild(cts, df),
704 dp+df->size, o, len, ip);
705 } /* Ignore all other entries in the chain. */
706 }
707}
708
709/* Initialize a struct/union with TValues. */
710static void cconv_struct_init(CTState *cts, CType *d, CTSize sz, uint8_t *dp,
711 TValue *o, MSize len)
712{
713 MSize i = 0;
714 memset(dp, 0, sz); /* Much simpler to clear the struct first. */
715 cconv_substruct_init(cts, d, dp, o, len, &i);
716 if (i < len)
717 cconv_err_initov(cts, d);
718}
719
720/* Check whether to use a multi-value initializer.
721** This is true if an aggregate is to be initialized with a value.
722** Valarrays are treated as values here so ct_tv handles (V|C, I|F).
723*/
724int lj_cconv_multi_init(CTState *cts, CType *d, TValue *o)
725{
726 if (!(ctype_isrefarray(d->info) || ctype_isstruct(d->info)))
727 return 0; /* Destination is not an aggregate. */
728 if (tvistab(o) || (tvisstr(o) && !ctype_isstruct(d->info)))
729 return 0; /* Initializer is not a value. */
730 if (tviscdata(o) && lj_ctype_rawref(cts, cdataV(o)->ctypeid) == d)
731 return 0; /* Source and destination are identical aggregates. */
732 return 1; /* Otherwise the initializer is a value. */
733}
734
735/* Initialize C type with TValues. Caveat: expects to get the raw CType! */
736void lj_cconv_ct_init(CTState *cts, CType *d, CTSize sz,
737 uint8_t *dp, TValue *o, MSize len)
738{
739 if (len == 0)
740 memset(dp, 0, sz);
741 else if (len == 1 && !lj_cconv_multi_init(cts, d, o))
742 lj_cconv_ct_tv(cts, d, dp, o, 0);
743 else if (ctype_isarray(d->info)) /* Also handles valarray init with len>1. */
744 cconv_array_init(cts, d, sz, dp, o, len);
745 else if (ctype_isstruct(d->info))
746 cconv_struct_init(cts, d, sz, dp, o, len);
747 else
748 cconv_err_initov(cts, d);
749}
750
751#endif
752