--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/luajit/src/lj_cdata.c	Thu Jan 22 20:10:30 2026 -0800
@@ -0,0 +1,304 @@
+/*
+** C data management.
+** Copyright (C) 2005-2023 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_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(lua_State *L, 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(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));
+  lj_assertL((char *)cd - p < 65536, "excessive cdata alignment");
+  cdatav(cd)->offset = (uint16_t)((char *)cd - p);
+  cdatav(cd)->extra = extra;
+  cdatav(cd)->len = sz;
+  g = G(L);
+  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;
+}
+
+/* Allocate arbitrary C data object. */
+GCcdata *lj_cdata_newx(CTState *cts, CTypeID id, CTSize sz, CTInfo info)
+{
+  if (!(info & CTF_VLA) && ctype_align(info) <= CT_MEMALIGN)
+    return lj_cdata_new(cts, id, sz);
+  else
+    return lj_cdata_newv(cts->L, id, sz, ctype_align(info));
+}
+
+/* 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;
+    lj_assertG(ctype_hassize(ct->info) || ctype_isfunc(ct->info) ||
+	       ctype_isextern(ct->info), "free of ctype without a size");
+    lj_mem_free(g, cd, sizeof(GCcdata) + sz);
+  } else {
+    lj_mem_free(g, memcdatav(cd), sizecdatav(cd));
+  }
+}
+
+void lj_cdata_setfin(lua_State *L, GCcdata *cd, GCobj *obj, uint32_t it)
+{
+  GCtab *t = ctype_ctsG(G(L))->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);
+    if (it == LJ_TNIL) {
+      setnilV(tv);
+      cd->marked &= ~LJ_GC_CDATA_FIN;
+    } else {
+      setgcV(L, tv, obj, it);
+      cd->marked |= LJ_GC_CDATA_FIN;
+    }
+  }
+}
+
+/* -- 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)) {
+    lj_assertCTS(ct->size == CTSIZE_PTR, "ref is not pointer-sized");
+    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);
+  }
+  /* Interning rejects refs to refs. */
+  lj_assertCTS(!ctype_isref(ct->info), "bad ref of ref");
+
+  if (tvisint(key)) {
+    idx = (ptrdiff_t)intV(key);
+    goto integer_key;
+  } else if (tvisnum(key)) {  /* Numeric key. */
+#ifdef _MSC_VER
+    /* Workaround for MSVC bug. */
+    volatile
+#endif
+    lua_Number n = numV(key);
+    idx = LJ_64 ? (ptrdiff_t)n : (ptrdiff_t)lj_num2int(n);
+  integer_key:
+    if (ctype_ispointer(ct->info)) {
+      CTSize sz = lj_ctype_size(cts, ctype_cid(ct->info));  /* Element size. */
+      if (sz == CTSIZE_INVALID)
+	lj_err_caller(cts->L, LJ_ERR_FFI_INVSIZE);
+      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);
+  lj_assertCTS(ctype_isinteger(ctt->info) && ctt->size <= 4,
+	       "only 32 bit const supported");  /* NYI */
+  /* 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. */
+  lj_assertCTS(ctype_ispointer(s->info) || ctype_isfield(s->info),
+	       "pointer or field expected");
+  sid = ctype_cid(s->info);
+  s = ctype_get(cts, sid);
+
+  /* Resolve reference for field. */
+  if (ctype_isref(s->info)) {
+    lj_assertCTS(s->size == CTSIZE_PTR, "ref is not pointer-sized");
+    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. */
+  lj_assertCTS(ctype_ispointer(d->info) || ctype_isfield(d->info),
+	       "pointer or field expected");
+  d = ctype_child(cts, d);
+
+  /* Resolve reference for field. */
+  if (ctype_isref(d->info)) {
+    lj_assertCTS(d->size == CTSIZE_PTR, "ref is not pointer-sized");
+    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);
+  }
+
+  lj_assertCTS(ctype_hassize(d->info), "store to ctype without size");
+  lj_assertCTS(!ctype_isvoid(d->info), "store to void type");
+
+  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