text: /*
  ** Auxiliary library for the Lua/C API.
  ** Copyright (C) 2005-2020 Mike Pall. See Copyright Notice in luajit.h
  **
  ** Major parts taken verbatim or adapted from the Lua interpreter.
  ** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h
  */
  
  #include <errno.h>
  #include <stdarg.h>
  #include <stdio.h>
  
  #define lib_aux_c
  #define LUA_LIB
  
  #include "lua.h"
  #include "lauxlib.h"
  
  #include "lj_obj.h"
  #include "lj_err.h"
  #include "lj_state.h"
  #include "lj_trace.h"
  #include "lj_lib.h"
  
  #if LJ_TARGET_POSIX
  #include <sys/wait.h>
  #endif
  
  /* -- I/O error handling -------------------------------------------------- */
  
  LUALIB_API int luaL_fileresult(lua_State *L, int stat, const char *fname)
  {
    if (stat) {
      setboolV(L->top++, 1);
      return 1;
    } else {
      int en = errno;  /* Lua API calls may change this value. */
      setnilV(L->top++);
      if (fname)
        lua_pushfstring(L, "%s: %s", fname, strerror(en));
      else
        lua_pushfstring(L, "%s", strerror(en));
      setintV(L->top++, en);
      lj_trace_abort(G(L));
      return 3;
    }
  }
  
  LUALIB_API int luaL_execresult(lua_State *L, int stat)
  {
    if (stat != -1) {
  #if LJ_TARGET_POSIX
      if (WIFSIGNALED(stat)) {
        stat = WTERMSIG(stat);
        setnilV(L->top++);
        lua_pushliteral(L, "signal");
      } else {
        if (WIFEXITED(stat))
  	stat = WEXITSTATUS(stat);
        if (stat == 0)
  	setboolV(L->top++, 1);
        else
  	setnilV(L->top++);
        lua_pushliteral(L, "exit");
      }
  #else
      if (stat == 0)
        setboolV(L->top++, 1);
      else
        setnilV(L->top++);
      lua_pushliteral(L, "exit");
  #endif
      setintV(L->top++, stat);
      return 3;
    }
    return luaL_fileresult(L, 0, NULL);
  }
  
  /* -- Module registration ------------------------------------------------- */
  
  LUALIB_API const char *luaL_findtable(lua_State *L, int idx,
  				      const char *fname, int szhint)
  {
    const char *e;
    lua_pushvalue(L, idx);
    do {
      e = strchr(fname, '.');
      if (e == NULL) e = fname + strlen(fname);
      lua_pushlstring(L, fname, (size_t)(e - fname));
      lua_rawget(L, -2);
      if (lua_isnil(L, -1)) {  /* no such field? */
        lua_pop(L, 1);  /* remove this nil */
        lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */
        lua_pushlstring(L, fname, (size_t)(e - fname));
        lua_pushvalue(L, -2);
        lua_settable(L, -4);  /* set new table into field */
      } else if (!lua_istable(L, -1)) {  /* field has a non-table value? */
        lua_pop(L, 2);  /* remove table and value */
        return fname;  /* return problematic part of the name */
      }
      lua_remove(L, -2);  /* remove previous table */
      fname = e + 1;
    } while (*e == '.');
    return NULL;
  }
  
  static int libsize(const luaL_Reg *l)
  {
    int size = 0;
    for (; l && l->name; l++) size++;
    return size;
  }
  
  LUALIB_API void luaL_pushmodule(lua_State *L, const char *modname, int sizehint)
  {
    luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 16);
    lua_getfield(L, -1, modname);
    if (!lua_istable(L, -1)) {
      lua_pop(L, 1);
      if (luaL_findtable(L, LUA_GLOBALSINDEX, modname, sizehint) != NULL)
        lj_err_callerv(L, LJ_ERR_BADMODN, modname);
      lua_pushvalue(L, -1);
      lua_setfield(L, -3, modname);  /* _LOADED[modname] = new table. */
    }
    lua_remove(L, -2);  /* Remove _LOADED table. */
  }
  
  LUALIB_API void luaL_openlib(lua_State *L, const char *libname,
  			     const luaL_Reg *l, int nup)
  {
    lj_lib_checkfpu(L);
    if (libname) {
      luaL_pushmodule(L, libname, libsize(l));
      lua_insert(L, -(nup + 1));  /* Move module table below upvalues. */
    }
    if (l)
      luaL_setfuncs(L, l, nup);
    else
      lua_pop(L, nup);  /* Remove upvalues. */
  }
  
  LUALIB_API void luaL_register(lua_State *L, const char *libname,
  			      const luaL_Reg *l)
  {
    luaL_openlib(L, libname, l, 0);
  }
  
  LUALIB_API void luaL_setfuncs(lua_State *L, const luaL_Reg *l, int nup)
  {
    luaL_checkstack(L, nup, "too many upvalues");
    for (; l->name; l++) {
      int i;
      for (i = 0; i < nup; i++)  /* Copy upvalues to the top. */
        lua_pushvalue(L, -nup);
      lua_pushcclosure(L, l->func, nup);
      lua_setfield(L, -(nup + 2), l->name);
    }
    lua_pop(L, nup);  /* Remove upvalues. */
  }
  
  LUALIB_API const char *luaL_gsub(lua_State *L, const char *s,
  				 const char *p, const char *r)
  {
    const char *wild;
    size_t l = strlen(p);
    luaL_Buffer b;
    luaL_buffinit(L, &b);
    while ((wild = strstr(s, p)) != NULL) {
      luaL_addlstring(&b, s, (size_t)(wild - s));  /* push prefix */
      luaL_addstring(&b, r);  /* push replacement in place of pattern */
      s = wild + l;  /* continue after `p' */
    }
    luaL_addstring(&b, s);  /* push last suffix */
    luaL_pushresult(&b);
    return lua_tostring(L, -1);
  }
  
  /* -- Buffer handling ----------------------------------------------------- */
  
  #define bufflen(B)	((size_t)((B)->p - (B)->buffer))
  #define bufffree(B)	((size_t)(LUAL_BUFFERSIZE - bufflen(B)))
  
  static int emptybuffer(luaL_Buffer *B)
  {
    size_t l = bufflen(B);
    if (l == 0)
      return 0;  /* put nothing on stack */
    lua_pushlstring(B->L, B->buffer, l);
    B->p = B->buffer;
    B->lvl++;
    return 1;
  }
  
  static void adjuststack(luaL_Buffer *B)
  {
    if (B->lvl > 1) {
      lua_State *L = B->L;
      int toget = 1;  /* number of levels to concat */
      size_t toplen = lua_strlen(L, -1);
      do {
        size_t l = lua_strlen(L, -(toget+1));
        if (!(B->lvl - toget + 1 >= LUA_MINSTACK/2 || toplen > l))
  	break;
        toplen += l;
        toget++;
      } while (toget < B->lvl);
      lua_concat(L, toget);
      B->lvl = B->lvl - toget + 1;
    }
  }
  
  LUALIB_API char *luaL_prepbuffer(luaL_Buffer *B)
  {
    if (emptybuffer(B))
      adjuststack(B);
    return B->buffer;
  }
  
  LUALIB_API void luaL_addlstring(luaL_Buffer *B, const char *s, size_t l)
  {
    if (l <= bufffree(B)) {
      memcpy(B->p, s, l);
      B->p += l;
    } else {
      emptybuffer(B);
      lua_pushlstring(B->L, s, l);
      B->lvl++;
      adjuststack(B);
    }
  }
  
  LUALIB_API void luaL_addstring(luaL_Buffer *B, const char *s)
  {
    luaL_addlstring(B, s, strlen(s));
  }
  
  LUALIB_API void luaL_pushresult(luaL_Buffer *B)
  {
    emptybuffer(B);
    lua_concat(B->L, B->lvl);
    B->lvl = 1;
  }
  
  LUALIB_API void luaL_addvalue(luaL_Buffer *B)
  {
    lua_State *L = B->L;
    size_t vl;
    const char *s = lua_tolstring(L, -1, &vl);
    if (vl <= bufffree(B)) {  /* fit into buffer? */
      memcpy(B->p, s, vl);  /* put it there */
      B->p += vl;
      lua_pop(L, 1);  /* remove from stack */
    } else {
      if (emptybuffer(B))
        lua_insert(L, -2);  /* put buffer before new value */
      B->lvl++;  /* add new value into B stack */
      adjuststack(B);
    }
  }
  
  LUALIB_API void luaL_buffinit(lua_State *L, luaL_Buffer *B)
  {
    B->L = L;
    B->p = B->buffer;
    B->lvl = 0;
  }
  
  /* -- Reference management ------------------------------------------------ */
  
  #define FREELIST_REF	0
  
  /* Convert a stack index to an absolute index. */
  #define abs_index(L, i) \
    ((i) > 0 || (i) <= LUA_REGISTRYINDEX ? (i) : lua_gettop(L) + (i) + 1)
  
  LUALIB_API int luaL_ref(lua_State *L, int t)
  {
    int ref;
    t = abs_index(L, t);
    if (lua_isnil(L, -1)) {
      lua_pop(L, 1);  /* remove from stack */
      return LUA_REFNIL;  /* `nil' has a unique fixed reference */
    }
    lua_rawgeti(L, t, FREELIST_REF);  /* get first free element */
    ref = (int)lua_tointeger(L, -1);  /* ref = t[FREELIST_REF] */
    lua_pop(L, 1);  /* remove it from stack */
    if (ref != 0) {  /* any free element? */
      lua_rawgeti(L, t, ref);  /* remove it from list */
      lua_rawseti(L, t, FREELIST_REF);  /* (t[FREELIST_REF] = t[ref]) */
    } else {  /* no free elements */
      ref = (int)lua_objlen(L, t);
      ref++;  /* create new reference */
    }
    lua_rawseti(L, t, ref);
    return ref;
  }
  
  LUALIB_API void luaL_unref(lua_State *L, int t, int ref)
  {
    if (ref >= 0) {
      t = abs_index(L, t);
      lua_rawgeti(L, t, FREELIST_REF);
      lua_rawseti(L, t, ref);  /* t[ref] = t[FREELIST_REF] */
      lua_pushinteger(L, ref);
      lua_rawseti(L, t, FREELIST_REF);  /* t[FREELIST_REF] = ref */
    }
  }
  
  /* -- Default allocator and panic function -------------------------------- */
  
  static int panic(lua_State *L)
  {
    const char *s = lua_tostring(L, -1);
    fputs("PANIC: unprotected error in call to Lua API (", stderr);
    fputs(s ? s : "?", stderr);
    fputc(')', stderr); fputc('\n', stderr);
    fflush(stderr);
    return 0;
  }
  
  #ifdef LUAJIT_USE_SYSMALLOC
  
  #if LJ_64 && !LJ_GC64 && !defined(LUAJIT_USE_VALGRIND)
  #error "Must use builtin allocator for 64 bit target"
  #endif
  
  static void *mem_alloc(void *ud, void *ptr, size_t osize, size_t nsize)
  {
    (void)ud;
    (void)osize;
    if (nsize == 0) {
      free(ptr);
      return NULL;
    } else {
      return realloc(ptr, nsize);
    }
  }
  
  LUALIB_API lua_State *luaL_newstate(void)
  {
    lua_State *L = lua_newstate(mem_alloc, NULL);
    if (L) G(L)->panic = panic;
    return L;
  }
  
  #else
  
  LUALIB_API lua_State *luaL_newstate(void)
  {
    lua_State *L;
  #if LJ_64 && !LJ_GC64
    L = lj_state_newstate(LJ_ALLOCF_INTERNAL, NULL);
  #else
    L = lua_newstate(LJ_ALLOCF_INTERNAL, NULL);
  #endif
    if (L) G(L)->panic = panic;
    return L;
  }
  
  #if LJ_64 && !LJ_GC64
  LUA_API lua_State *lua_newstate(lua_Alloc f, void *ud)
  {
    UNUSED(f); UNUSED(ud);
    fputs("Must use luaL_newstate() for 64 bit target\n", stderr);
    return NULL;
  }
  #endif
  
  #endif
  
  