--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/luajit/src/lj_bcread.c	Thu Jan 22 20:10:30 2026 -0800
@@ -0,0 +1,453 @@
+/*
+** Bytecode reader.
+** Copyright (C) 2005-2023 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#define lj_bcread_c
+#define LUA_CORE
+
+#include "lj_obj.h"
+#include "lj_gc.h"
+#include "lj_err.h"
+#include "lj_buf.h"
+#include "lj_str.h"
+#include "lj_tab.h"
+#include "lj_bc.h"
+#if LJ_HASFFI
+#include "lj_ctype.h"
+#include "lj_cdata.h"
+#include "lualib.h"
+#endif
+#include "lj_lex.h"
+#include "lj_bcdump.h"
+#include "lj_state.h"
+#include "lj_strfmt.h"
+
+/* Reuse some lexer fields for our own purposes. */
+#define bcread_flags(ls)	ls->level
+#define bcread_swap(ls) \
+  ((bcread_flags(ls) & BCDUMP_F_BE) != LJ_BE*BCDUMP_F_BE)
+#define bcread_oldtop(L, ls)	restorestack(L, ls->lastline)
+#define bcread_savetop(L, ls, top) \
+  ls->lastline = (BCLine)savestack(L, (top))
+
+/* -- Input buffer handling ----------------------------------------------- */
+
+/* Throw reader error. */
+static LJ_NOINLINE void bcread_error(LexState *ls, ErrMsg em)
+{
+  lua_State *L = ls->L;
+  const char *name = ls->chunkarg;
+  if (*name == BCDUMP_HEAD1) name = "(binary)";
+  else if (*name == '@' || *name == '=') name++;
+  lj_strfmt_pushf(L, "%s: %s", name, err2msg(em));
+  lj_err_throw(L, LUA_ERRSYNTAX);
+}
+
+/* Refill buffer. */
+static LJ_NOINLINE void bcread_fill(LexState *ls, MSize len, int need)
+{
+  lj_assertLS(len != 0, "empty refill");
+  if (len > LJ_MAX_BUF || ls->c < 0)
+    bcread_error(ls, LJ_ERR_BCBAD);
+  do {
+    const char *buf;
+    size_t sz;
+    char *p = ls->sb.b;
+    MSize n = (MSize)(ls->pe - ls->p);
+    if (n) {  /* Copy remainder to buffer. */
+      if (sbuflen(&ls->sb)) {  /* Move down in buffer. */
+	lj_assertLS(ls->pe == ls->sb.w, "bad buffer pointer");
+	if (ls->p != p) memmove(p, ls->p, n);
+      } else {  /* Copy from buffer provided by reader. */
+	p = lj_buf_need(&ls->sb, len);
+	memcpy(p, ls->p, n);
+      }
+      ls->p = p;
+      ls->pe = p + n;
+    }
+    ls->sb.w = p + n;
+    buf = ls->rfunc(ls->L, ls->rdata, &sz);  /* Get more data from reader. */
+    if (buf == NULL || sz == 0) {  /* EOF? */
+      if (need) bcread_error(ls, LJ_ERR_BCBAD);
+      ls->c = -1;  /* Only bad if we get called again. */
+      break;
+    }
+    if (sz >= LJ_MAX_BUF - n) lj_err_mem(ls->L);
+    if (n) {  /* Append to buffer. */
+      n += (MSize)sz;
+      p = lj_buf_need(&ls->sb, n < len ? len : n);
+      memcpy(ls->sb.w, buf, sz);
+      ls->sb.w = p + n;
+      ls->p = p;
+      ls->pe = p + n;
+    } else {  /* Return buffer provided by reader. */
+      ls->p = buf;
+      ls->pe = buf + sz;
+    }
+  } while ((MSize)(ls->pe - ls->p) < len);
+}
+
+/* Need a certain number of bytes. */
+static LJ_AINLINE void bcread_need(LexState *ls, MSize len)
+{
+  if (LJ_UNLIKELY((MSize)(ls->pe - ls->p) < len))
+    bcread_fill(ls, len, 1);
+}
+
+/* Want to read up to a certain number of bytes, but may need less. */
+static LJ_AINLINE void bcread_want(LexState *ls, MSize len)
+{
+  if (LJ_UNLIKELY((MSize)(ls->pe - ls->p) < len))
+    bcread_fill(ls, len, 0);
+}
+
+/* Return memory block from buffer. */
+static LJ_AINLINE uint8_t *bcread_mem(LexState *ls, MSize len)
+{
+  uint8_t *p = (uint8_t *)ls->p;
+  ls->p += len;
+  lj_assertLS(ls->p <= ls->pe, "buffer read overflow");
+  return p;
+}
+
+/* Copy memory block from buffer. */
+static void bcread_block(LexState *ls, void *q, MSize len)
+{
+  memcpy(q, bcread_mem(ls, len), len);
+}
+
+/* Read byte from buffer. */
+static LJ_AINLINE uint32_t bcread_byte(LexState *ls)
+{
+  lj_assertLS(ls->p < ls->pe, "buffer read overflow");
+  return (uint32_t)(uint8_t)*ls->p++;
+}
+
+/* Read ULEB128 value from buffer. */
+static LJ_AINLINE uint32_t bcread_uleb128(LexState *ls)
+{
+  uint32_t v = lj_buf_ruleb128(&ls->p);
+  lj_assertLS(ls->p <= ls->pe, "buffer read overflow");
+  return v;
+}
+
+/* Read top 32 bits of 33 bit ULEB128 value from buffer. */
+static uint32_t bcread_uleb128_33(LexState *ls)
+{
+  const uint8_t *p = (const uint8_t *)ls->p;
+  uint32_t v = (*p++ >> 1);
+  if (LJ_UNLIKELY(v >= 0x40)) {
+    int sh = -1;
+    v &= 0x3f;
+    do {
+     v |= ((*p & 0x7f) << (sh += 7));
+   } while (*p++ >= 0x80);
+  }
+  ls->p = (char *)p;
+  lj_assertLS(ls->p <= ls->pe, "buffer read overflow");
+  return v;
+}
+
+/* -- Bytecode reader ----------------------------------------------------- */
+
+/* Read debug info of a prototype. */
+static void bcread_dbg(LexState *ls, GCproto *pt, MSize sizedbg)
+{
+  void *lineinfo = (void *)proto_lineinfo(pt);
+  bcread_block(ls, lineinfo, sizedbg);
+  /* Swap lineinfo if the endianess differs. */
+  if (bcread_swap(ls) && pt->numline >= 256) {
+    MSize i, n = pt->sizebc-1;
+    if (pt->numline < 65536) {
+      uint16_t *p = (uint16_t *)lineinfo;
+      for (i = 0; i < n; i++) p[i] = (uint16_t)((p[i] >> 8)|(p[i] << 8));
+    } else {
+      uint32_t *p = (uint32_t *)lineinfo;
+      for (i = 0; i < n; i++) p[i] = lj_bswap(p[i]);
+    }
+  }
+}
+
+/* Find pointer to varinfo. */
+static const void *bcread_varinfo(GCproto *pt)
+{
+  const uint8_t *p = proto_uvinfo(pt);
+  MSize n = pt->sizeuv;
+  if (n) while (*p++ || --n) ;
+  return p;
+}
+
+/* Read a single constant key/value of a template table. */
+static void bcread_ktabk(LexState *ls, TValue *o)
+{
+  MSize tp = bcread_uleb128(ls);
+  if (tp >= BCDUMP_KTAB_STR) {
+    MSize len = tp - BCDUMP_KTAB_STR;
+    const char *p = (const char *)bcread_mem(ls, len);
+    setstrV(ls->L, o, lj_str_new(ls->L, p, len));
+  } else if (tp == BCDUMP_KTAB_INT) {
+    setintV(o, (int32_t)bcread_uleb128(ls));
+  } else if (tp == BCDUMP_KTAB_NUM) {
+    o->u32.lo = bcread_uleb128(ls);
+    o->u32.hi = bcread_uleb128(ls);
+  } else {
+    lj_assertLS(tp <= BCDUMP_KTAB_TRUE, "bad constant type %d", tp);
+    setpriV(o, ~tp);
+  }
+}
+
+/* Read a template table. */
+static GCtab *bcread_ktab(LexState *ls)
+{
+  MSize narray = bcread_uleb128(ls);
+  MSize nhash = bcread_uleb128(ls);
+  GCtab *t = lj_tab_new(ls->L, narray, hsize2hbits(nhash));
+  if (narray) {  /* Read array entries. */
+    MSize i;
+    TValue *o = tvref(t->array);
+    for (i = 0; i < narray; i++, o++)
+      bcread_ktabk(ls, o);
+  }
+  if (nhash) {  /* Read hash entries. */
+    MSize i;
+    for (i = 0; i < nhash; i++) {
+      TValue key;
+      bcread_ktabk(ls, &key);
+      lj_assertLS(!tvisnil(&key), "nil key");
+      bcread_ktabk(ls, lj_tab_set(ls->L, t, &key));
+    }
+  }
+  return t;
+}
+
+/* Read GC constants of a prototype. */
+static void bcread_kgc(LexState *ls, GCproto *pt, MSize sizekgc)
+{
+  MSize i;
+  GCRef *kr = mref(pt->k, GCRef) - (ptrdiff_t)sizekgc;
+  for (i = 0; i < sizekgc; i++, kr++) {
+    MSize tp = bcread_uleb128(ls);
+    if (tp >= BCDUMP_KGC_STR) {
+      MSize len = tp - BCDUMP_KGC_STR;
+      const char *p = (const char *)bcread_mem(ls, len);
+      setgcref(*kr, obj2gco(lj_str_new(ls->L, p, len)));
+    } else if (tp == BCDUMP_KGC_TAB) {
+      setgcref(*kr, obj2gco(bcread_ktab(ls)));
+#if LJ_HASFFI
+    } else if (tp != BCDUMP_KGC_CHILD) {
+      CTypeID id = tp == BCDUMP_KGC_COMPLEX ? CTID_COMPLEX_DOUBLE :
+		   tp == BCDUMP_KGC_I64 ? CTID_INT64 : CTID_UINT64;
+      CTSize sz = tp == BCDUMP_KGC_COMPLEX ? 16 : 8;
+      GCcdata *cd = lj_cdata_new_(ls->L, id, sz);
+      TValue *p = (TValue *)cdataptr(cd);
+      setgcref(*kr, obj2gco(cd));
+      p[0].u32.lo = bcread_uleb128(ls);
+      p[0].u32.hi = bcread_uleb128(ls);
+      if (tp == BCDUMP_KGC_COMPLEX) {
+	p[1].u32.lo = bcread_uleb128(ls);
+	p[1].u32.hi = bcread_uleb128(ls);
+      }
+#endif
+    } else {
+      lua_State *L = ls->L;
+      lj_assertLS(tp == BCDUMP_KGC_CHILD, "bad constant type %d", tp);
+      if (L->top <= bcread_oldtop(L, ls))  /* Stack underflow? */
+	bcread_error(ls, LJ_ERR_BCBAD);
+      L->top--;
+      setgcref(*kr, obj2gco(protoV(L->top)));
+    }
+  }
+}
+
+/* Read number constants of a prototype. */
+static void bcread_knum(LexState *ls, GCproto *pt, MSize sizekn)
+{
+  MSize i;
+  TValue *o = mref(pt->k, TValue);
+  for (i = 0; i < sizekn; i++, o++) {
+    int isnum = (ls->p[0] & 1);
+    uint32_t lo = bcread_uleb128_33(ls);
+    if (isnum) {
+      o->u32.lo = lo;
+      o->u32.hi = bcread_uleb128(ls);
+    } else {
+      setintV(o, lo);
+    }
+  }
+}
+
+/* Read bytecode instructions. */
+static void bcread_bytecode(LexState *ls, GCproto *pt, MSize sizebc)
+{
+  BCIns *bc = proto_bc(pt);
+  bc[0] = BCINS_AD((pt->flags & PROTO_VARARG) ? BC_FUNCV : BC_FUNCF,
+		   pt->framesize, 0);
+  bcread_block(ls, bc+1, (sizebc-1)*(MSize)sizeof(BCIns));
+  /* Swap bytecode instructions if the endianess differs. */
+  if (bcread_swap(ls)) {
+    MSize i;
+    for (i = 1; i < sizebc; i++) bc[i] = lj_bswap(bc[i]);
+  }
+}
+
+/* Read upvalue refs. */
+static void bcread_uv(LexState *ls, GCproto *pt, MSize sizeuv)
+{
+  if (sizeuv) {
+    uint16_t *uv = proto_uv(pt);
+    bcread_block(ls, uv, sizeuv*2);
+    /* Swap upvalue refs if the endianess differs. */
+    if (bcread_swap(ls)) {
+      MSize i;
+      for (i = 0; i < sizeuv; i++)
+	uv[i] = (uint16_t)((uv[i] >> 8)|(uv[i] << 8));
+    }
+  }
+}
+
+/* Read a prototype. */
+GCproto *lj_bcread_proto(LexState *ls)
+{
+  GCproto *pt;
+  MSize framesize, numparams, flags, sizeuv, sizekgc, sizekn, sizebc, sizept;
+  MSize ofsk, ofsuv, ofsdbg;
+  MSize sizedbg = 0;
+  BCLine firstline = 0, numline = 0;
+
+  /* Read prototype header. */
+  flags = bcread_byte(ls);
+  numparams = bcread_byte(ls);
+  framesize = bcread_byte(ls);
+  sizeuv = bcread_byte(ls);
+  sizekgc = bcread_uleb128(ls);
+  sizekn = bcread_uleb128(ls);
+  sizebc = bcread_uleb128(ls) + 1;
+  if (!(bcread_flags(ls) & BCDUMP_F_STRIP)) {
+    sizedbg = bcread_uleb128(ls);
+    if (sizedbg) {
+      firstline = bcread_uleb128(ls);
+      numline = bcread_uleb128(ls);
+    }
+  }
+
+  /* Calculate total size of prototype including all colocated arrays. */
+  sizept = (MSize)sizeof(GCproto) +
+	   sizebc*(MSize)sizeof(BCIns) +
+	   sizekgc*(MSize)sizeof(GCRef);
+  sizept = (sizept + (MSize)sizeof(TValue)-1) & ~((MSize)sizeof(TValue)-1);
+  ofsk = sizept; sizept += sizekn*(MSize)sizeof(TValue);
+  ofsuv = sizept; sizept += ((sizeuv+1)&~1)*2;
+  ofsdbg = sizept; sizept += sizedbg;
+
+  /* Allocate prototype object and initialize its fields. */
+  pt = (GCproto *)lj_mem_newgco(ls->L, (MSize)sizept);
+  pt->gct = ~LJ_TPROTO;
+  pt->numparams = (uint8_t)numparams;
+  pt->framesize = (uint8_t)framesize;
+  pt->sizebc = sizebc;
+  setmref(pt->k, (char *)pt + ofsk);
+  setmref(pt->uv, (char *)pt + ofsuv);
+  pt->sizekgc = 0;  /* Set to zero until fully initialized. */
+  pt->sizekn = sizekn;
+  pt->sizept = sizept;
+  pt->sizeuv = (uint8_t)sizeuv;
+  pt->flags = (uint8_t)flags;
+  pt->trace = 0;
+  setgcref(pt->chunkname, obj2gco(ls->chunkname));
+
+  /* Close potentially uninitialized gap between bc and kgc. */
+  *(uint32_t *)((char *)pt + ofsk - sizeof(GCRef)*(sizekgc+1)) = 0;
+
+  /* Read bytecode instructions and upvalue refs. */
+  bcread_bytecode(ls, pt, sizebc);
+  bcread_uv(ls, pt, sizeuv);
+
+  /* Read constants. */
+  bcread_kgc(ls, pt, sizekgc);
+  pt->sizekgc = sizekgc;
+  bcread_knum(ls, pt, sizekn);
+
+  /* Read and initialize debug info. */
+  pt->firstline = firstline;
+  pt->numline = numline;
+  if (sizedbg) {
+    MSize sizeli = (sizebc-1) << (numline < 256 ? 0 : numline < 65536 ? 1 : 2);
+    setmref(pt->lineinfo, (char *)pt + ofsdbg);
+    setmref(pt->uvinfo, (char *)pt + ofsdbg + sizeli);
+    bcread_dbg(ls, pt, sizedbg);
+    setmref(pt->varinfo, bcread_varinfo(pt));
+  } else {
+    setmref(pt->lineinfo, NULL);
+    setmref(pt->uvinfo, NULL);
+    setmref(pt->varinfo, NULL);
+  }
+  return pt;
+}
+
+/* Read and check header of bytecode dump. */
+static int bcread_header(LexState *ls)
+{
+  uint32_t flags;
+  bcread_want(ls, 3+5+5);
+  if (bcread_byte(ls) != BCDUMP_HEAD2 ||
+      bcread_byte(ls) != BCDUMP_HEAD3 ||
+      bcread_byte(ls) != BCDUMP_VERSION) return 0;
+  bcread_flags(ls) = flags = bcread_uleb128(ls);
+  if ((flags & ~(BCDUMP_F_KNOWN)) != 0) return 0;
+  if ((flags & BCDUMP_F_FR2) != LJ_FR2*BCDUMP_F_FR2) return 0;
+  if ((flags & BCDUMP_F_FFI)) {
+#if LJ_HASFFI
+    lua_State *L = ls->L;
+    ctype_loadffi(L);
+#else
+    return 0;
+#endif
+  }
+  if ((flags & BCDUMP_F_STRIP)) {
+    ls->chunkname = lj_str_newz(ls->L, ls->chunkarg);
+  } else {
+    MSize len = bcread_uleb128(ls);
+    bcread_need(ls, len);
+    ls->chunkname = lj_str_new(ls->L, (const char *)bcread_mem(ls, len), len);
+  }
+  return 1;  /* Ok. */
+}
+
+/* Read a bytecode dump. */
+GCproto *lj_bcread(LexState *ls)
+{
+  lua_State *L = ls->L;
+  lj_assertLS(ls->c == BCDUMP_HEAD1, "bad bytecode header");
+  bcread_savetop(L, ls, L->top);
+  lj_buf_reset(&ls->sb);
+  /* Check for a valid bytecode dump header. */
+  if (!bcread_header(ls))
+    bcread_error(ls, LJ_ERR_BCFMT);
+  for (;;) {  /* Process all prototypes in the bytecode dump. */
+    GCproto *pt;
+    MSize len;
+    const char *startp;
+    /* Read length. */
+    if (ls->p < ls->pe && ls->p[0] == 0) {  /* Shortcut EOF. */
+      ls->p++;
+      break;
+    }
+    bcread_want(ls, 5);
+    len = bcread_uleb128(ls);
+    if (!len) break;  /* EOF */
+    bcread_need(ls, len);
+    startp = ls->p;
+    pt = lj_bcread_proto(ls);
+    if (ls->p != startp + len)
+      bcread_error(ls, LJ_ERR_BCBAD);
+    setprotoV(L, L->top, pt);
+    incr_top(L);
+  }
+  if ((ls->pe != ls->p && !ls->endmark) || L->top-1 != bcread_oldtop(L, ls))
+    bcread_error(ls, LJ_ERR_BCBAD);
+  /* Pop off last prototype. */
+  L->top--;
+  return protoV(L->top);
+}
+