--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/luajit/src/lj_func.c	Fri Jan 23 22:38:59 2026 -0800
@@ -0,0 +1,191 @@
+/*
+** Function handling (prototypes, functions and upvalues).
+** Copyright (C) 2005-2023 Mike Pall. See Copyright Notice in luajit.h
+**
+** Portions taken verbatim or adapted from the Lua interpreter.
+** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h
+*/
+
+#define lj_func_c
+#define LUA_CORE
+
+#include "lj_obj.h"
+#include "lj_gc.h"
+#include "lj_func.h"
+#include "lj_trace.h"
+#include "lj_vm.h"
+
+/* -- Prototypes ---------------------------------------------------------- */
+
+void LJ_FASTCALL lj_func_freeproto(global_State *g, GCproto *pt)
+{
+  lj_mem_free(g, pt, pt->sizept);
+}
+
+/* -- Upvalues ------------------------------------------------------------ */
+
+static void unlinkuv(global_State *g, GCupval *uv)
+{
+  UNUSED(g);
+  lj_assertG(uvprev(uvnext(uv)) == uv && uvnext(uvprev(uv)) == uv,
+	     "broken upvalue chain");
+  setgcrefr(uvnext(uv)->prev, uv->prev);
+  setgcrefr(uvprev(uv)->next, uv->next);
+}
+
+/* Find existing open upvalue for a stack slot or create a new one. */
+static GCupval *func_finduv(lua_State *L, TValue *slot)
+{
+  global_State *g = G(L);
+  GCRef *pp = &L->openupval;
+  GCupval *p;
+  GCupval *uv;
+  /* Search the sorted list of open upvalues. */
+  while (gcref(*pp) != NULL && uvval((p = gco2uv(gcref(*pp)))) >= slot) {
+    lj_assertG(!p->closed && uvval(p) != &p->tv, "closed upvalue in chain");
+    if (uvval(p) == slot) {  /* Found open upvalue pointing to same slot? */
+      if (isdead(g, obj2gco(p)))  /* Resurrect it, if it's dead. */
+	flipwhite(obj2gco(p));
+      return p;
+    }
+    pp = &p->nextgc;
+  }
+  /* No matching upvalue found. Create a new one. */
+  uv = lj_mem_newt(L, sizeof(GCupval), GCupval);
+  newwhite(g, uv);
+  uv->gct = ~LJ_TUPVAL;
+  uv->closed = 0;  /* Still open. */
+  setmref(uv->v, slot);  /* Pointing to the stack slot. */
+  /* NOBARRIER: The GCupval is new (marked white) and open. */
+  setgcrefr(uv->nextgc, *pp);  /* Insert into sorted list of open upvalues. */
+  setgcref(*pp, obj2gco(uv));
+  setgcref(uv->prev, obj2gco(&g->uvhead));  /* Insert into GC list, too. */
+  setgcrefr(uv->next, g->uvhead.next);
+  setgcref(uvnext(uv)->prev, obj2gco(uv));
+  setgcref(g->uvhead.next, obj2gco(uv));
+  lj_assertG(uvprev(uvnext(uv)) == uv && uvnext(uvprev(uv)) == uv,
+	     "broken upvalue chain");
+  return uv;
+}
+
+/* Create an empty and closed upvalue. */
+static GCupval *func_emptyuv(lua_State *L)
+{
+  GCupval *uv = (GCupval *)lj_mem_newgco(L, sizeof(GCupval));
+  uv->gct = ~LJ_TUPVAL;
+  uv->closed = 1;
+  setnilV(&uv->tv);
+  setmref(uv->v, &uv->tv);
+  return uv;
+}
+
+/* Close all open upvalues pointing to some stack level or above. */
+void LJ_FASTCALL lj_func_closeuv(lua_State *L, TValue *level)
+{
+  GCupval *uv;
+  global_State *g = G(L);
+  while (gcref(L->openupval) != NULL &&
+	 uvval((uv = gco2uv(gcref(L->openupval)))) >= level) {
+    GCobj *o = obj2gco(uv);
+    lj_assertG(!isblack(o), "bad black upvalue");
+    lj_assertG(!uv->closed && uvval(uv) != &uv->tv, "closed upvalue in chain");
+    setgcrefr(L->openupval, uv->nextgc);  /* No longer in open list. */
+    if (isdead(g, o)) {
+      lj_func_freeuv(g, uv);
+    } else {
+      unlinkuv(g, uv);
+      lj_gc_closeuv(g, uv);
+    }
+  }
+}
+
+void LJ_FASTCALL lj_func_freeuv(global_State *g, GCupval *uv)
+{
+  if (!uv->closed)
+    unlinkuv(g, uv);
+  lj_mem_freet(g, uv);
+}
+
+/* -- Functions (closures) ------------------------------------------------ */
+
+GCfunc *lj_func_newC(lua_State *L, MSize nelems, GCtab *env)
+{
+  GCfunc *fn = (GCfunc *)lj_mem_newgco(L, sizeCfunc(nelems));
+  fn->c.gct = ~LJ_TFUNC;
+  fn->c.ffid = FF_C;
+  fn->c.nupvalues = (uint8_t)nelems;
+  /* NOBARRIER: The GCfunc is new (marked white). */
+  setmref(fn->c.pc, &G(L)->bc_cfunc_ext);
+  setgcref(fn->c.env, obj2gco(env));
+  return fn;
+}
+
+static GCfunc *func_newL(lua_State *L, GCproto *pt, GCtab *env)
+{
+  uint32_t count;
+  GCfunc *fn = (GCfunc *)lj_mem_newgco(L, sizeLfunc((MSize)pt->sizeuv));
+  fn->l.gct = ~LJ_TFUNC;
+  fn->l.ffid = FF_LUA;
+  fn->l.nupvalues = 0;  /* Set to zero until upvalues are initialized. */
+  /* NOBARRIER: Really a setgcref. But the GCfunc is new (marked white). */
+  setmref(fn->l.pc, proto_bc(pt));
+  setgcref(fn->l.env, obj2gco(env));
+  /* Saturating 3 bit counter (0..7) for created closures. */
+  count = (uint32_t)pt->flags + PROTO_CLCOUNT;
+  pt->flags = (uint8_t)(count - ((count >> PROTO_CLC_BITS) & PROTO_CLCOUNT));
+  return fn;
+}
+
+/* Create a new Lua function with empty upvalues. */
+GCfunc *lj_func_newL_empty(lua_State *L, GCproto *pt, GCtab *env)
+{
+  GCfunc *fn = func_newL(L, pt, env);
+  MSize i, nuv = pt->sizeuv;
+  /* NOBARRIER: The GCfunc is new (marked white). */
+  for (i = 0; i < nuv; i++) {
+    GCupval *uv = func_emptyuv(L);
+    int32_t v = proto_uv(pt)[i];
+    uv->immutable = ((v / PROTO_UV_IMMUTABLE) & 1);
+    uv->dhash = (uint32_t)(uintptr_t)pt ^ (v << 24);
+    setgcref(fn->l.uvptr[i], obj2gco(uv));
+  }
+  fn->l.nupvalues = (uint8_t)nuv;
+  return fn;
+}
+
+/* Do a GC check and create a new Lua function with inherited upvalues. */
+GCfunc *lj_func_newL_gc(lua_State *L, GCproto *pt, GCfuncL *parent)
+{
+  GCfunc *fn;
+  GCRef *puv;
+  MSize i, nuv;
+  TValue *base;
+  lj_gc_check_fixtop(L);
+  fn = func_newL(L, pt, tabref(parent->env));
+  /* NOBARRIER: The GCfunc is new (marked white). */
+  puv = parent->uvptr;
+  nuv = pt->sizeuv;
+  base = L->base;
+  for (i = 0; i < nuv; i++) {
+    uint32_t v = proto_uv(pt)[i];
+    GCupval *uv;
+    if ((v & PROTO_UV_LOCAL)) {
+      uv = func_finduv(L, base + (v & 0xff));
+      uv->immutable = ((v / PROTO_UV_IMMUTABLE) & 1);
+      uv->dhash = (uint32_t)(uintptr_t)mref(parent->pc, char) ^ (v << 24);
+    } else {
+      uv = &gcref(puv[v])->uv;
+    }
+    setgcref(fn->l.uvptr[i], obj2gco(uv));
+  }
+  fn->l.nupvalues = (uint8_t)nuv;
+  return fn;
+}
+
+void LJ_FASTCALL lj_func_free(global_State *g, GCfunc *fn)
+{
+  MSize size = isluafunc(fn) ? sizeLfunc((MSize)fn->l.nupvalues) :
+			       sizeCfunc((MSize)fn->c.nupvalues);
+  lj_mem_free(g, fn, size);
+}
+