--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/luajit/src/lj_str.c	Thu Jan 22 20:10:30 2026 -0800
@@ -0,0 +1,370 @@
+/*
+** String handling.
+** Copyright (C) 2005-2023 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#define lj_str_c
+#define LUA_CORE
+
+#include "lj_obj.h"
+#include "lj_gc.h"
+#include "lj_err.h"
+#include "lj_str.h"
+#include "lj_char.h"
+#include "lj_prng.h"
+
+/* -- String helpers ------------------------------------------------------ */
+
+/* Ordered compare of strings. Assumes string data is 4-byte aligned. */
+int32_t LJ_FASTCALL lj_str_cmp(GCstr *a, GCstr *b)
+{
+  MSize i, n = a->len > b->len ? b->len : a->len;
+  for (i = 0; i < n; i += 4) {
+    /* Note: innocuous access up to end of string + 3. */
+    uint32_t va = *(const uint32_t *)(strdata(a)+i);
+    uint32_t vb = *(const uint32_t *)(strdata(b)+i);
+    if (va != vb) {
+#if LJ_LE
+      va = lj_bswap(va); vb = lj_bswap(vb);
+#endif
+      i -= n;
+      if ((int32_t)i >= -3) {
+	va >>= 32+(i<<3); vb >>= 32+(i<<3);
+	if (va == vb) break;
+      }
+      return va < vb ? -1 : 1;
+    }
+  }
+  return (int32_t)(a->len - b->len);
+}
+
+/* Find fixed string p inside string s. */
+const char *lj_str_find(const char *s, const char *p, MSize slen, MSize plen)
+{
+  if (plen <= slen) {
+    if (plen == 0) {
+      return s;
+    } else {
+      int c = *(const uint8_t *)p++;
+      plen--; slen -= plen;
+      while (slen) {
+	const char *q = (const char *)memchr(s, c, slen);
+	if (!q) break;
+	if (memcmp(q+1, p, plen) == 0) return q;
+	q++; slen -= (MSize)(q-s); s = q;
+      }
+    }
+  }
+  return NULL;
+}
+
+/* Check whether a string has a pattern matching character. */
+int lj_str_haspattern(GCstr *s)
+{
+  const char *p = strdata(s), *q = p + s->len;
+  while (p < q) {
+    int c = *(const uint8_t *)p++;
+    if (lj_char_ispunct(c) && strchr("^$*+?.([%-", c))
+      return 1;  /* Found a pattern matching char. */
+  }
+  return 0;  /* No pattern matching chars found. */
+}
+
+/* -- String hashing ------------------------------------------------------ */
+
+/* Keyed sparse ARX string hash. Constant time. */
+static StrHash hash_sparse(uint64_t seed, const char *str, MSize len)
+{
+  /* Constants taken from lookup3 hash by Bob Jenkins. */
+  StrHash a, b, h = len ^ (StrHash)seed;
+  if (len >= 4) {  /* Caveat: unaligned access! */
+    a = lj_getu32(str);
+    h ^= lj_getu32(str+len-4);
+    b = lj_getu32(str+(len>>1)-2);
+    h ^= b; h -= lj_rol(b, 14);
+    b += lj_getu32(str+(len>>2)-1);
+  } else {
+    a = *(const uint8_t *)str;
+    h ^= *(const uint8_t *)(str+len-1);
+    b = *(const uint8_t *)(str+(len>>1));
+    h ^= b; h -= lj_rol(b, 14);
+  }
+  a ^= h; a -= lj_rol(h, 11);
+  b ^= a; b -= lj_rol(a, 25);
+  h ^= b; h -= lj_rol(b, 16);
+  return h;
+}
+
+#if LUAJIT_SECURITY_STRHASH
+/* Keyed dense ARX string hash. Linear time. */
+static LJ_NOINLINE StrHash hash_dense(uint64_t seed, StrHash h,
+				      const char *str, MSize len)
+{
+  StrHash b = lj_bswap(lj_rol(h ^ (StrHash)(seed >> 32), 4));
+  if (len > 12) {
+    StrHash a = (StrHash)seed;
+    const char *pe = str+len-12, *p = pe, *q = str;
+    do {
+      a += lj_getu32(p);
+      b += lj_getu32(p+4);
+      h += lj_getu32(p+8);
+      p = q; q += 12;
+      h ^= b; h -= lj_rol(b, 14);
+      a ^= h; a -= lj_rol(h, 11);
+      b ^= a; b -= lj_rol(a, 25);
+    } while (p < pe);
+    h ^= b; h -= lj_rol(b, 16);
+    a ^= h; a -= lj_rol(h, 4);
+    b ^= a; b -= lj_rol(a, 14);
+  }
+  return b;
+}
+#endif
+
+/* -- String interning ---------------------------------------------------- */
+
+#define LJ_STR_MAXCOLL		32
+
+/* Resize the string interning hash table (grow and shrink). */
+void lj_str_resize(lua_State *L, MSize newmask)
+{
+  global_State *g = G(L);
+  GCRef *newtab, *oldtab = g->str.tab;
+  MSize i;
+
+  /* No resizing during GC traversal or if already too big. */
+  if (g->gc.state == GCSsweepstring || newmask >= LJ_MAX_STRTAB-1)
+    return;
+
+  newtab = lj_mem_newvec(L, newmask+1, GCRef);
+  memset(newtab, 0, (newmask+1)*sizeof(GCRef));
+
+#if LUAJIT_SECURITY_STRHASH
+  /* Check which chains need secondary hashes. */
+  if (g->str.second) {
+    int newsecond = 0;
+    /* Compute primary chain lengths. */
+    for (i = g->str.mask; i != ~(MSize)0; i--) {
+      GCobj *o = (GCobj *)(gcrefu(oldtab[i]) & ~(uintptr_t)1);
+      while (o) {
+	GCstr *s = gco2str(o);
+	MSize hash = s->hashalg ? hash_sparse(g->str.seed, strdata(s), s->len) :
+				  s->hash;
+	hash &= newmask;
+	setgcrefp(newtab[hash], gcrefu(newtab[hash]) + 1);
+	o = gcnext(o);
+      }
+    }
+    /* Mark secondary chains. */
+    for (i = newmask; i != ~(MSize)0; i--) {
+      int secondary = gcrefu(newtab[i]) > LJ_STR_MAXCOLL;
+      newsecond |= secondary;
+      setgcrefp(newtab[i], secondary);
+    }
+    g->str.second = newsecond;
+  }
+#endif
+
+  /* Reinsert all strings from the old table into the new table. */
+  for (i = g->str.mask; i != ~(MSize)0; i--) {
+    GCobj *o = (GCobj *)(gcrefu(oldtab[i]) & ~(uintptr_t)1);
+    while (o) {
+      GCobj *next = gcnext(o);
+      GCstr *s = gco2str(o);
+      MSize hash = s->hash;
+#if LUAJIT_SECURITY_STRHASH
+      uintptr_t u;
+      if (LJ_LIKELY(!s->hashalg)) {  /* String hashed with primary hash. */
+	hash &= newmask;
+	u = gcrefu(newtab[hash]);
+	if (LJ_UNLIKELY(u & 1)) {  /* Switch string to secondary hash. */
+	  s->hash = hash = hash_dense(g->str.seed, s->hash, strdata(s), s->len);
+	  s->hashalg = 1;
+	  hash &= newmask;
+	  u = gcrefu(newtab[hash]);
+	}
+      } else {  /* String hashed with secondary hash. */
+	MSize shash = hash_sparse(g->str.seed, strdata(s), s->len);
+	u = gcrefu(newtab[shash & newmask]);
+	if (u & 1) {
+	  hash &= newmask;
+	  u = gcrefu(newtab[hash]);
+	} else {  /* Revert string back to primary hash. */
+	  s->hash = shash;
+	  s->hashalg = 0;
+	  hash = (shash & newmask);
+	}
+      }
+      /* NOBARRIER: The string table is a GC root. */
+      setgcrefp(o->gch.nextgc, (u & ~(uintptr_t)1));
+      setgcrefp(newtab[hash], ((uintptr_t)o | (u & 1)));
+#else
+      hash &= newmask;
+      /* NOBARRIER: The string table is a GC root. */
+      setgcrefr(o->gch.nextgc, newtab[hash]);
+      setgcref(newtab[hash], o);
+#endif
+      o = next;
+    }
+  }
+
+  /* Free old table and replace with new table. */
+  lj_str_freetab(g);
+  g->str.tab = newtab;
+  g->str.mask = newmask;
+}
+
+#if LUAJIT_SECURITY_STRHASH
+/* Rehash and rechain all strings in a chain. */
+static LJ_NOINLINE GCstr *lj_str_rehash_chain(lua_State *L, StrHash hashc,
+					      const char *str, MSize len)
+{
+  global_State *g = G(L);
+  int ow = g->gc.state == GCSsweepstring ? otherwhite(g) : 0;  /* Sweeping? */
+  GCRef *strtab = g->str.tab;
+  MSize strmask = g->str.mask;
+  GCobj *o = gcref(strtab[hashc & strmask]);
+  setgcrefp(strtab[hashc & strmask], (void *)((uintptr_t)1));
+  g->str.second = 1;
+  while (o) {
+    uintptr_t u;
+    GCobj *next = gcnext(o);
+    GCstr *s = gco2str(o);
+    StrHash hash;
+    if (ow) {  /* Must sweep while rechaining. */
+      if (((o->gch.marked ^ LJ_GC_WHITES) & ow)) {  /* String alive? */
+	lj_assertG(!isdead(g, o) || (o->gch.marked & LJ_GC_FIXED),
+		   "sweep of undead string");
+	makewhite(g, o);
+      } else {  /* Free dead string. */
+	lj_assertG(isdead(g, o) || ow == LJ_GC_SFIXED,
+		   "sweep of unlive string");
+	lj_str_free(g, s);
+	o = next;
+	continue;
+      }
+    }
+    hash = s->hash;
+    if (!s->hashalg) {  /* Rehash with secondary hash. */
+      hash = hash_dense(g->str.seed, hash, strdata(s), s->len);
+      s->hash = hash;
+      s->hashalg = 1;
+    }
+    /* Rechain. */
+    hash &= strmask;
+    u = gcrefu(strtab[hash]);
+    setgcrefp(o->gch.nextgc, (u & ~(uintptr_t)1));
+    setgcrefp(strtab[hash], ((uintptr_t)o | (u & 1)));
+    o = next;
+  }
+  /* Try to insert the pending string again. */
+  return lj_str_new(L, str, len);
+}
+#endif
+
+/* Reseed String ID from PRNG after random interval < 2^bits. */
+#if LUAJIT_SECURITY_STRID == 1
+#define STRID_RESEED_INTERVAL	8
+#elif LUAJIT_SECURITY_STRID == 2
+#define STRID_RESEED_INTERVAL	4
+#elif LUAJIT_SECURITY_STRID >= 3
+#define STRID_RESEED_INTERVAL	0
+#endif
+
+/* Allocate a new string and add to string interning table. */
+static GCstr *lj_str_alloc(lua_State *L, const char *str, MSize len,
+			   StrHash hash, int hashalg)
+{
+  GCstr *s = lj_mem_newt(L, lj_str_size(len), GCstr);
+  global_State *g = G(L);
+  uintptr_t u;
+  newwhite(g, s);
+  s->gct = ~LJ_TSTR;
+  s->len = len;
+  s->hash = hash;
+#ifndef STRID_RESEED_INTERVAL
+  s->sid = g->str.id++;
+#elif STRID_RESEED_INTERVAL
+  if (!g->str.idreseed--) {
+    uint64_t r = lj_prng_u64(&g->prng);
+    g->str.id = (StrID)r;
+    g->str.idreseed = (uint8_t)(r >> (64 - STRID_RESEED_INTERVAL));
+  }
+  s->sid = g->str.id++;
+#else
+  s->sid = (StrID)lj_prng_u64(&g->prng);
+#endif
+  s->reserved = 0;
+  s->hashalg = (uint8_t)hashalg;
+  /* Clear last 4 bytes of allocated memory. Implies zero-termination, too. */
+  *(uint32_t *)(strdatawr(s)+(len & ~(MSize)3)) = 0;
+  memcpy(strdatawr(s), str, len);
+  /* Add to string hash table. */
+  hash &= g->str.mask;
+  u = gcrefu(g->str.tab[hash]);
+  setgcrefp(s->nextgc, (u & ~(uintptr_t)1));
+  /* NOBARRIER: The string table is a GC root. */
+  setgcrefp(g->str.tab[hash], ((uintptr_t)s | (u & 1)));
+  if (g->str.num++ > g->str.mask)  /* Allow a 100% load factor. */
+    lj_str_resize(L, (g->str.mask<<1)+1);  /* Grow string table. */
+  return s;  /* Return newly interned string. */
+}
+
+/* Intern a string and return string object. */
+GCstr *lj_str_new(lua_State *L, const char *str, size_t lenx)
+{
+  global_State *g = G(L);
+  if (lenx-1 < LJ_MAX_STR-1) {
+    MSize len = (MSize)lenx;
+    StrHash hash = hash_sparse(g->str.seed, str, len);
+    MSize coll = 0;
+    int hashalg = 0;
+    /* Check if the string has already been interned. */
+    GCobj *o = gcref(g->str.tab[hash & g->str.mask]);
+#if LUAJIT_SECURITY_STRHASH
+    if (LJ_UNLIKELY((uintptr_t)o & 1)) {  /* Secondary hash for this chain? */
+      hashalg = 1;
+      hash = hash_dense(g->str.seed, hash, str, len);
+      o = (GCobj *)(gcrefu(g->str.tab[hash & g->str.mask]) & ~(uintptr_t)1);
+    }
+#endif
+    while (o != NULL) {
+      GCstr *sx = gco2str(o);
+      if (sx->hash == hash && sx->len == len) {
+	if (memcmp(str, strdata(sx), len) == 0) {
+	  if (isdead(g, o)) flipwhite(o);  /* Resurrect if dead. */
+	  return sx;  /* Return existing string. */
+	}
+	coll++;
+      }
+      coll++;
+      o = gcnext(o);
+    }
+#if LUAJIT_SECURITY_STRHASH
+    /* Rehash chain if there are too many collisions. */
+    if (LJ_UNLIKELY(coll > LJ_STR_MAXCOLL) && !hashalg) {
+      return lj_str_rehash_chain(L, hash, str, len);
+    }
+#endif
+    /* Otherwise allocate a new string. */
+    return lj_str_alloc(L, str, len, hash, hashalg);
+  } else {
+    if (lenx)
+      lj_err_msg(L, LJ_ERR_STROV);
+    return &g->strempty;
+  }
+}
+
+void LJ_FASTCALL lj_str_free(global_State *g, GCstr *s)
+{
+  g->str.num--;
+  lj_mem_free(g, s, lj_str_size(s->len));
+}
+
+void LJ_FASTCALL lj_str_init(lua_State *L)
+{
+  global_State *g = G(L);
+  g->str.seed = lj_prng_u64(&g->prng);
+  lj_str_resize(L, LJ_MIN_STRTAB-1);
+}
+