diff options
Diffstat (limited to 'luajit-2.0/src/lj_cdata.c')
| -rw-r--r-- | luajit-2.0/src/lj_cdata.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/luajit-2.0/src/lj_cdata.c b/luajit-2.0/src/lj_cdata.c new file mode 100644 index 0000000..590ddf1 --- /dev/null +++ b/luajit-2.0/src/lj_cdata.c @@ -0,0 +1,285 @@ +/* +** C data management. +** Copyright (C) 2005-2014 Mike Pall. See Copyright Notice in luajit.h +*/ + +#include "lj_obj.h" + +#if LJ_HASFFI + +#include "lj_gc.h" +#include "lj_err.h" +#include "lj_str.h" +#include "lj_tab.h" +#include "lj_ctype.h" +#include "lj_cconv.h" +#include "lj_cdata.h" + +/* -- C data allocation --------------------------------------------------- */ + +/* Allocate a new C data object holding a reference to another object. */ +GCcdata *lj_cdata_newref(CTState *cts, const void *p, CTypeID id) +{ + CTypeID refid = lj_ctype_intern(cts, CTINFO_REF(id), CTSIZE_PTR); + GCcdata *cd = lj_cdata_new(cts, refid, CTSIZE_PTR); + *(const void **)cdataptr(cd) = p; + return cd; +} + +/* Allocate variable-sized or specially aligned C data object. */ +GCcdata *lj_cdata_newv(CTState *cts, CTypeID id, CTSize sz, CTSize align) +{ + global_State *g; + MSize extra = sizeof(GCcdataVar) + sizeof(GCcdata) + + (align > CT_MEMALIGN ? (1u<<align) - (1u<<CT_MEMALIGN) : 0); + char *p = lj_mem_newt(cts->L, extra + sz, char); + uintptr_t adata = (uintptr_t)p + sizeof(GCcdataVar) + sizeof(GCcdata); + uintptr_t almask = (1u << align) - 1u; + GCcdata *cd = (GCcdata *)(((adata + almask) & ~almask) - sizeof(GCcdata)); + lua_assert((char *)cd - p < 65536); + cdatav(cd)->offset = (uint16_t)((char *)cd - p); + cdatav(cd)->extra = extra; + cdatav(cd)->len = sz; + g = cts->g; + setgcrefr(cd->nextgc, g->gc.root); + setgcref(g->gc.root, obj2gco(cd)); + newwhite(g, obj2gco(cd)); + cd->marked |= 0x80; + cd->gct = ~LJ_TCDATA; + cd->ctypeid = id; + return cd; +} + +/* Free a C data object. */ +void LJ_FASTCALL lj_cdata_free(global_State *g, GCcdata *cd) +{ + if (LJ_UNLIKELY(cd->marked & LJ_GC_CDATA_FIN)) { + GCobj *root; + makewhite(g, obj2gco(cd)); + markfinalized(obj2gco(cd)); + if ((root = gcref(g->gc.mmudata)) != NULL) { + setgcrefr(cd->nextgc, root->gch.nextgc); + setgcref(root->gch.nextgc, obj2gco(cd)); + setgcref(g->gc.mmudata, obj2gco(cd)); + } else { + setgcref(cd->nextgc, obj2gco(cd)); + setgcref(g->gc.mmudata, obj2gco(cd)); + } + } else if (LJ_LIKELY(!cdataisv(cd))) { + CType *ct = ctype_raw(ctype_ctsG(g), cd->ctypeid); + CTSize sz = ctype_hassize(ct->info) ? ct->size : CTSIZE_PTR; + lua_assert(ctype_hassize(ct->info) || ctype_isfunc(ct->info) || + ctype_isextern(ct->info)); + lj_mem_free(g, cd, sizeof(GCcdata) + sz); + } else { + lj_mem_free(g, memcdatav(cd), sizecdatav(cd)); + } +} + +TValue * LJ_FASTCALL lj_cdata_setfin(lua_State *L, GCcdata *cd) +{ + global_State *g = G(L); + GCtab *t = ctype_ctsG(g)->finalizer; + if (gcref(t->metatable)) { + /* Add cdata to finalizer table, if still enabled. */ + TValue *tv, tmp; + setcdataV(L, &tmp, cd); + lj_gc_anybarriert(L, t); + tv = lj_tab_set(L, t, &tmp); + cd->marked |= LJ_GC_CDATA_FIN; + return tv; + } else { + /* Otherwise return dummy TValue. */ + return &g->tmptv; + } +} + +/* -- C data indexing ----------------------------------------------------- */ + +/* Index C data by a TValue. Return CType and pointer. */ +CType *lj_cdata_index(CTState *cts, GCcdata *cd, cTValue *key, uint8_t **pp, + CTInfo *qual) +{ + uint8_t *p = (uint8_t *)cdataptr(cd); + CType *ct = ctype_get(cts, cd->ctypeid); + ptrdiff_t idx; + + /* Resolve reference for cdata object. */ + if (ctype_isref(ct->info)) { + lua_assert(ct->size == CTSIZE_PTR); + p = *(uint8_t **)p; + ct = ctype_child(cts, ct); + } + +collect_attrib: + /* Skip attributes and collect qualifiers. */ + while (ctype_isattrib(ct->info)) { + if (ctype_attrib(ct->info) == CTA_QUAL) *qual |= ct->size; + ct = ctype_child(cts, ct); + } + lua_assert(!ctype_isref(ct->info)); /* Interning rejects refs to refs. */ + + if (tvisint(key)) { + idx = (ptrdiff_t)intV(key); + goto integer_key; + } else if (tvisnum(key)) { /* Numeric key. */ + idx = LJ_64 ? (ptrdiff_t)numV(key) : (ptrdiff_t)lj_num2int(numV(key)); + integer_key: + if (ctype_ispointer(ct->info)) { + CTSize sz = lj_ctype_size(cts, ctype_cid(ct->info)); /* Element size. */ + if (sz != CTSIZE_INVALID) { + if (ctype_isptr(ct->info)) { + p = (uint8_t *)cdata_getptr(p, ct->size); + } else if ((ct->info & (CTF_VECTOR|CTF_COMPLEX))) { + if ((ct->info & CTF_COMPLEX)) idx &= 1; + *qual |= CTF_CONST; /* Valarray elements are constant. */ + } + *pp = p + idx*(int32_t)sz; + return ct; + } + } + } else if (tviscdata(key)) { /* Integer cdata key. */ + GCcdata *cdk = cdataV(key); + CType *ctk = ctype_raw(cts, cdk->ctypeid); + if (ctype_isenum(ctk->info)) ctk = ctype_child(cts, ctk); + if (ctype_isinteger(ctk->info)) { + lj_cconv_ct_ct(cts, ctype_get(cts, CTID_INT_PSZ), ctk, + (uint8_t *)&idx, cdataptr(cdk), 0); + goto integer_key; + } + } else if (tvisstr(key)) { /* String key. */ + GCstr *name = strV(key); + if (ctype_isstruct(ct->info)) { + CTSize ofs; + CType *fct = lj_ctype_getfieldq(cts, ct, name, &ofs, qual); + if (fct) { + *pp = p + ofs; + return fct; + } + } else if (ctype_iscomplex(ct->info)) { + if (name->len == 2) { + *qual |= CTF_CONST; /* Complex fields are constant. */ + if (strdata(name)[0] == 'r' && strdata(name)[1] == 'e') { + *pp = p; + return ct; + } else if (strdata(name)[0] == 'i' && strdata(name)[1] == 'm') { + *pp = p + (ct->size >> 1); + return ct; + } + } + } else if (cd->ctypeid == CTID_CTYPEID) { + /* Allow indexing a (pointer to) struct constructor to get constants. */ + CType *sct = ctype_raw(cts, *(CTypeID *)p); + if (ctype_isptr(sct->info)) + sct = ctype_rawchild(cts, sct); + if (ctype_isstruct(sct->info)) { + CTSize ofs; + CType *fct = lj_ctype_getfield(cts, sct, name, &ofs); + if (fct && ctype_isconstval(fct->info)) + return fct; + } + ct = sct; /* Allow resolving metamethods for constructors, too. */ + } + } + if (ctype_isptr(ct->info)) { /* Automatically perform '->'. */ + if (ctype_isstruct(ctype_rawchild(cts, ct)->info)) { + p = (uint8_t *)cdata_getptr(p, ct->size); + ct = ctype_child(cts, ct); + goto collect_attrib; + } + } + *qual |= 1; /* Lookup failed. */ + return ct; /* But return the resolved raw type. */ +} + +/* -- C data getters ------------------------------------------------------ */ + +/* Get constant value and convert to TValue. */ +static void cdata_getconst(CTState *cts, TValue *o, CType *ct) +{ + CType *ctt = ctype_child(cts, ct); + lua_assert(ctype_isinteger(ctt->info) && ctt->size <= 4); + /* Constants are already zero-extended/sign-extended to 32 bits. */ + if ((ctt->info & CTF_UNSIGNED) && (int32_t)ct->size < 0) + setnumV(o, (lua_Number)(uint32_t)ct->size); + else + setintV(o, (int32_t)ct->size); +} + +/* Get C data value and convert to TValue. */ +int lj_cdata_get(CTState *cts, CType *s, TValue *o, uint8_t *sp) +{ + CTypeID sid; + + if (ctype_isconstval(s->info)) { + cdata_getconst(cts, o, s); + return 0; /* No GC step needed. */ + } else if (ctype_isbitfield(s->info)) { + return lj_cconv_tv_bf(cts, s, o, sp); + } + + /* Get child type of pointer/array/field. */ + lua_assert(ctype_ispointer(s->info) || ctype_isfield(s->info)); + sid = ctype_cid(s->info); + s = ctype_get(cts, sid); + + /* Resolve reference for field. */ + if (ctype_isref(s->info)) { + lua_assert(s->size == CTSIZE_PTR); + sp = *(uint8_t **)sp; + sid = ctype_cid(s->info); + s = ctype_get(cts, sid); + } + + /* Skip attributes. */ + while (ctype_isattrib(s->info)) + s = ctype_child(cts, s); + + return lj_cconv_tv_ct(cts, s, sid, o, sp); +} + +/* -- C data setters ------------------------------------------------------ */ + +/* Convert TValue and set C data value. */ +void lj_cdata_set(CTState *cts, CType *d, uint8_t *dp, TValue *o, CTInfo qual) +{ + if (ctype_isconstval(d->info)) { + goto err_const; + } else if (ctype_isbitfield(d->info)) { + if (((d->info|qual) & CTF_CONST)) goto err_const; + lj_cconv_bf_tv(cts, d, dp, o); + return; + } + + /* Get child type of pointer/array/field. */ + lua_assert(ctype_ispointer(d->info) || ctype_isfield(d->info)); + d = ctype_child(cts, d); + + /* Resolve reference for field. */ + if (ctype_isref(d->info)) { + lua_assert(d->size == CTSIZE_PTR); + dp = *(uint8_t **)dp; + d = ctype_child(cts, d); + } + + /* Skip attributes and collect qualifiers. */ + for (;;) { + if (ctype_isattrib(d->info)) { + if (ctype_attrib(d->info) == CTA_QUAL) qual |= d->size; + } else { + break; + } + d = ctype_child(cts, d); + } + + lua_assert(ctype_hassize(d->info) && !ctype_isvoid(d->info)); + + if (((d->info|qual) & CTF_CONST)) { + err_const: + lj_err_caller(cts->L, LJ_ERR_FFI_WRCONST); + } + + lj_cconv_ct_tv(cts, d, dp, o, 0); +} + +#endif |