--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/luajit/src/lj_lib.h	Fri Jan 23 22:38:59 2026 -0800
@@ -0,0 +1,116 @@
+/*
+** Library function support.
+** Copyright (C) 2005-2023 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#ifndef _LJ_LIB_H
+#define _LJ_LIB_H
+
+#include "lj_obj.h"
+
+/*
+** A fallback handler is called by the assembler VM if the fast path fails:
+**
+** - too few arguments:   unrecoverable.
+** - wrong argument type:   recoverable, if coercion succeeds.
+** - bad argument value:  unrecoverable.
+** - stack overflow:        recoverable, if stack reallocation succeeds.
+** - extra handling:        recoverable.
+**
+** The unrecoverable cases throw an error with lj_err_arg(), lj_err_argtype(),
+** lj_err_caller() or lj_err_callermsg().
+** The recoverable cases return 0 or the number of results + 1.
+** The assembler VM retries the fast path only if 0 is returned.
+** This time the fallback must not be called again or it gets stuck in a loop.
+*/
+
+/* Return values from fallback handler. */
+#define FFH_RETRY	0
+#define FFH_UNREACHABLE	FFH_RETRY
+#define FFH_RES(n)	((n)+1)
+#define FFH_TAILCALL	(-1)
+
+LJ_FUNC TValue *lj_lib_checkany(lua_State *L, int narg);
+LJ_FUNC GCstr *lj_lib_checkstr(lua_State *L, int narg);
+LJ_FUNC GCstr *lj_lib_optstr(lua_State *L, int narg);
+#if LJ_DUALNUM
+LJ_FUNC void lj_lib_checknumber(lua_State *L, int narg);
+#else
+#define lj_lib_checknumber(L, narg)	lj_lib_checknum((L), (narg))
+#endif
+LJ_FUNC lua_Number lj_lib_checknum(lua_State *L, int narg);
+LJ_FUNC int32_t lj_lib_checkint(lua_State *L, int narg);
+LJ_FUNC int32_t lj_lib_optint(lua_State *L, int narg, int32_t def);
+LJ_FUNC GCfunc *lj_lib_checkfunc(lua_State *L, int narg);
+LJ_FUNC GCtab *lj_lib_checktab(lua_State *L, int narg);
+LJ_FUNC GCtab *lj_lib_checktabornil(lua_State *L, int narg);
+LJ_FUNC int lj_lib_checkopt(lua_State *L, int narg, int def, const char *lst);
+
+#if LJ_HASBUFFER
+LJ_FUNC GCstr *lj_lib_checkstrx(lua_State *L, int narg);
+LJ_FUNC int32_t lj_lib_checkintrange(lua_State *L, int narg,
+				     int32_t a, int32_t b);
+#endif
+
+/* Avoid including lj_frame.h. */
+#if LJ_GC64
+#define lj_lib_upvalue(L, n) \
+  (&gcval(L->base-2)->fn.c.upvalue[(n)-1])
+#elif LJ_FR2
+#define lj_lib_upvalue(L, n) \
+  (&gcref((L->base-2)->gcr)->fn.c.upvalue[(n)-1])
+#else
+#define lj_lib_upvalue(L, n) \
+  (&gcref((L->base-1)->fr.func)->fn.c.upvalue[(n)-1])
+#endif
+
+#if LJ_TARGET_WINDOWS
+#define lj_lib_checkfpu(L) \
+  do { setnumV(L->top++, (lua_Number)1437217655); \
+    if (lua_tointeger(L, -1) != 1437217655) lj_err_caller(L, LJ_ERR_BADFPU); \
+    L->top--; } while (0)
+#else
+#define lj_lib_checkfpu(L)	UNUSED(L)
+#endif
+
+LJ_FUNC GCfunc *lj_lib_pushcc(lua_State *L, lua_CFunction f, int id, int n);
+#define lj_lib_pushcf(L, fn, id)	(lj_lib_pushcc(L, (fn), (id), 0))
+
+/* Library function declarations. Scanned by buildvm. */
+#define LJLIB_CF(name)		static int lj_cf_##name(lua_State *L)
+#define LJLIB_ASM(name)		static int lj_ffh_##name(lua_State *L)
+#define LJLIB_ASM_(name)
+#define LJLIB_LUA(name)
+#define LJLIB_SET(name)
+#define LJLIB_PUSH(arg)
+#define LJLIB_REC(handler)
+#define LJLIB_NOREGUV
+#define LJLIB_NOREG
+
+#define LJ_LIB_REG(L, regname, name) \
+  lj_lib_register(L, regname, lj_lib_init_##name, lj_lib_cf_##name)
+
+LJ_FUNC void lj_lib_register(lua_State *L, const char *libname,
+			     const uint8_t *init, const lua_CFunction *cf);
+LJ_FUNC void lj_lib_prereg(lua_State *L, const char *name, lua_CFunction f,
+			   GCtab *env);
+LJ_FUNC int lj_lib_postreg(lua_State *L, lua_CFunction cf, int id,
+			   const char *name);
+
+/* Library init data tags. */
+#define LIBINIT_LENMASK	0x3f
+#define LIBINIT_TAGMASK	0xc0
+#define LIBINIT_CF	0x00
+#define LIBINIT_ASM	0x40
+#define LIBINIT_ASM_	0x80
+#define LIBINIT_STRING	0xc0
+#define LIBINIT_MAXSTR	0x38
+#define LIBINIT_LUA	0xf9
+#define LIBINIT_SET	0xfa
+#define LIBINIT_NUMBER	0xfb
+#define LIBINIT_COPY	0xfc
+#define LIBINIT_LASTCL	0xfd
+#define LIBINIT_FFID	0xfe
+#define LIBINIT_END	0xff
+
+#endif