Merge commit '7333333568b13db56136e2354c55556adc7714ed' as 'vendor/compat53'

2 files changed, 1005 insertions, 0 deletions

diff --git a/vendor/compat53/c-api/compat-5.3.c b/vendor/compat53/c-api/compat-5.3.c
new file mode 100644
index 0000000..883efb8
--- /dev/null
+++ b/vendor/compat53/c-api/compat-5.3.c
@@ -0,0 +1,617 @@
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include "compat-5.3.h"
+
+/* don't compile it again if it already is included via compat53.h */
+#ifndef COMPAT53_C_
+#define COMPAT53_C_
+
+
+
+/* definitions for Lua 5.1 only */
+#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM == 501
+
+
+COMPAT53_API int lua_absindex (lua_State *L, int i) {
+  if (i < 0 && i > LUA_REGISTRYINDEX)
+    i += lua_gettop(L) + 1;
+  return i;
+}
+
+
+static void compat53_call_lua (lua_State *L, char const code[], size_t len,
+                               int nargs, int nret) {
+  lua_rawgetp(L, LUA_REGISTRYINDEX, (void*)code);
+  if (lua_type(L, -1) != LUA_TFUNCTION) {
+    lua_pop(L, 1);
+    if (luaL_loadbuffer(L, code, len, "=none"))
+      lua_error(L);
+    lua_pushvalue(L, -1);
+    lua_rawsetp(L, LUA_REGISTRYINDEX, (void*)code);
+  }
+  lua_insert(L, -nargs-1);
+  lua_call(L, nargs, nret);
+}
+
+
+static const char compat53_arith_code[] =
+  "local op,a,b=...\n"
+  "if op==0 then return a+b\n"
+  "elseif op==1 then return a-b\n"
+  "elseif op==2 then return a*b\n"
+  "elseif op==3 then return a/b\n"
+  "elseif op==4 then return a%b\n"
+  "elseif op==5 then return a^b\n"
+  "elseif op==6 then return -a\n"
+  "end\n";
+
+COMPAT53_API void lua_arith (lua_State *L, int op) {
+  if (op < LUA_OPADD || op > LUA_OPUNM)
+    luaL_error(L, "invalid 'op' argument for lua_arith");
+  luaL_checkstack(L, 5, "not enough stack slots");
+  if (op == LUA_OPUNM)
+    lua_pushvalue(L, -1);
+  lua_pushnumber(L, op);
+  lua_insert(L, -3);
+  compat53_call_lua(L, compat53_arith_code,
+                    sizeof(compat53_arith_code)-1, 3, 1);
+}
+
+
+static const char compat53_compare_code[] =
+  "local a,b=...\n"
+  "return a<=b\n";
+
+COMPAT53_API int lua_compare (lua_State *L, int idx1, int idx2, int op) {
+  int result = 0;
+  switch (op) {
+    case LUA_OPEQ:
+      return lua_equal(L, idx1, idx2);
+    case LUA_OPLT:
+      return lua_lessthan(L, idx1, idx2);
+    case LUA_OPLE:
+      luaL_checkstack(L, 5, "not enough stack slots");
+      idx1 = lua_absindex(L, idx1);
+      idx2 = lua_absindex(L, idx2);
+      lua_pushvalue(L, idx1);
+      lua_pushvalue(L, idx2);
+      compat53_call_lua(L, compat53_compare_code,
+                        sizeof(compat53_compare_code)-1, 2, 1);
+      result = lua_toboolean(L, -1);
+      lua_pop(L, 1);
+      return result;
+    default:
+      luaL_error(L, "invalid 'op' argument for lua_compare");
+  }
+  return 0;
+}
+
+
+COMPAT53_API void lua_copy (lua_State *L, int from, int to) {
+  int abs_to = lua_absindex(L, to);
+  luaL_checkstack(L, 1, "not enough stack slots");
+  lua_pushvalue(L, from);
+  lua_replace(L, abs_to);
+}
+
+
+COMPAT53_API void lua_len (lua_State *L, int i) {
+  switch (lua_type(L, i)) {
+    case LUA_TSTRING:
+      lua_pushnumber(L, (lua_Integer)lua_objlen(L, i));
+      break;
+    case LUA_TTABLE:
+      if (!luaL_callmeta(L, i, "__len"))
+        lua_pushnumber(L, (lua_Integer)lua_objlen(L, i));
+      break;
+    case LUA_TUSERDATA:
+      if (luaL_callmeta(L, i, "__len"))
+        break;
+      /* maybe fall through */
+    default:
+      luaL_error(L, "attempt to get length of a %s value",
+                 lua_typename(L, lua_type(L, i)));
+  }
+}
+
+
+COMPAT53_API int lua_rawgetp (lua_State *L, int i, const void *p) {
+  int abs_i = lua_absindex(L, i);
+  lua_pushlightuserdata(L, (void*)p);
+  lua_rawget(L, abs_i);
+  return lua_type(L, -1);
+}
+
+COMPAT53_API void lua_rawsetp (lua_State *L, int i, const void *p) {
+  int abs_i = lua_absindex(L, i);
+  luaL_checkstack(L, 1, "not enough stack slots");
+  lua_pushlightuserdata(L, (void*)p);
+  lua_insert(L, -2);
+  lua_rawset(L, abs_i);
+}
+
+
+COMPAT53_API lua_Integer lua_tointegerx (lua_State *L, int i, int *isnum) {
+  lua_Integer n = lua_tointeger(L, i);
+  if (isnum != NULL) {
+    *isnum = (n != 0 || lua_isnumber(L, i));
+  }
+  return n;
+}
+
+
+COMPAT53_API lua_Number lua_tonumberx (lua_State *L, int i, int *isnum) {
+  lua_Number n = lua_tonumber(L, i);
+  if (isnum != NULL) {
+    *isnum = (n != 0 || lua_isnumber(L, i));
+  }
+  return n;
+}
+
+
+COMPAT53_API void luaL_checkversion (lua_State *L) {
+  (void)L;
+}
+
+
+COMPAT53_API void luaL_checkstack (lua_State *L, int sp, const char *msg) {
+  if (!lua_checkstack(L, sp+LUA_MINSTACK)) {
+    if (msg != NULL)
+      luaL_error(L, "stack overflow (%s)", msg);
+    else {
+      lua_pushliteral(L, "stack overflow");
+      lua_error(L);
+    }
+  }
+}
+
+
+COMPAT53_API int luaL_getsubtable (lua_State *L, int i, const char *name) {
+  int abs_i = lua_absindex(L, i);
+  luaL_checkstack(L, 3, "not enough stack slots");
+  lua_pushstring(L, name);
+  lua_gettable(L, abs_i);
+  if (lua_istable(L, -1))
+    return 1;
+  lua_pop(L, 1);
+  lua_newtable(L);
+  lua_pushstring(L, name);
+  lua_pushvalue(L, -2);
+  lua_settable(L, abs_i);
+  return 0;
+}
+
+
+COMPAT53_API lua_Integer luaL_len (lua_State *L, int i) {
+  lua_Integer res = 0;
+  int isnum = 0;
+  luaL_checkstack(L, 1, "not enough stack slots");
+  lua_len(L, i);
+  res = lua_tointegerx(L, -1, &isnum);
+  lua_pop(L, 1);
+  if (!isnum)
+    luaL_error(L, "object length is not an integer");
+  return res;
+}
+
+
+COMPAT53_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
+  luaL_checkstack(L, nup+1, "too many upvalues");
+  for (; l->name != NULL; l++) {  /* fill the table with given functions */
+    int i;
+    lua_pushstring(L, l->name);
+    for (i = 0; i < nup; i++)  /* copy upvalues to the top */
+      lua_pushvalue(L, -(nup + 1));
+    lua_pushcclosure(L, l->func, nup);  /* closure with those upvalues */
+    lua_settable(L, -(nup + 3)); /* table must be below the upvalues, the name and the closure */
+  }
+  lua_pop(L, nup);  /* remove upvalues */
+}
+
+
+COMPAT53_API void luaL_setmetatable (lua_State *L, const char *tname) {
+  luaL_checkstack(L, 1, "not enough stack slots");
+  luaL_getmetatable(L, tname);
+  lua_setmetatable(L, -2);
+}
+
+
+COMPAT53_API void *luaL_testudata (lua_State *L, int i, const char *tname) {
+  void *p = lua_touserdata(L, i);
+  luaL_checkstack(L, 2, "not enough stack slots");
+  if (p == NULL || !lua_getmetatable(L, i))
+    return NULL;
+  else {
+    int res = 0;
+    luaL_getmetatable(L, tname);
+    res = lua_rawequal(L, -1, -2);
+    lua_pop(L, 2);
+    if (!res)
+      p = NULL;
+  }
+  return p;
+}
+
+
+static int compat53_countlevels (lua_State *L) {
+  lua_Debug ar;
+  int li = 1, le = 1;
+  /* find an upper bound */
+  while (lua_getstack(L, le, &ar)) { li = le; le *= 2; }
+  /* do a binary search */
+  while (li < le) {
+    int m = (li + le)/2;
+    if (lua_getstack(L, m, &ar)) li = m + 1;
+    else le = m;
+  }
+  return le - 1;
+}
+
+static int compat53_findfield (lua_State *L, int objidx, int level) {
+  if (level == 0 || !lua_istable(L, -1))
+    return 0;  /* not found */
+  lua_pushnil(L);  /* start 'next' loop */
+  while (lua_next(L, -2)) {  /* for each pair in table */
+    if (lua_type(L, -2) == LUA_TSTRING) {  /* ignore non-string keys */
+      if (lua_rawequal(L, objidx, -1)) {  /* found object? */
+        lua_pop(L, 1);  /* remove value (but keep name) */
+        return 1;
+      }
+      else if (compat53_findfield(L, objidx, level - 1)) {  /* try recursively */
+        lua_remove(L, -2);  /* remove table (but keep name) */
+        lua_pushliteral(L, ".");
+        lua_insert(L, -2);  /* place '.' between the two names */
+        lua_concat(L, 3);
+        return 1;
+      }
+    }
+    lua_pop(L, 1);  /* remove value */
+  }
+  return 0;  /* not found */
+}
+
+static int compat53_pushglobalfuncname (lua_State *L, lua_Debug *ar) {
+  int top = lua_gettop(L);
+  lua_getinfo(L, "f", ar);  /* push function */
+  lua_pushvalue(L, LUA_GLOBALSINDEX);
+  if (compat53_findfield(L, top + 1, 2)) {
+    lua_copy(L, -1, top + 1);  /* move name to proper place */
+    lua_pop(L, 2);  /* remove pushed values */
+    return 1;
+  }
+  else {
+    lua_settop(L, top);  /* remove function and global table */
+    return 0;
+  }
+}
+
+static void compat53_pushfuncname (lua_State *L, lua_Debug *ar) {
+  if (*ar->namewhat != '\0')  /* is there a name? */
+    lua_pushfstring(L, "function " LUA_QS, ar->name);
+  else if (*ar->what == 'm')  /* main? */
+      lua_pushliteral(L, "main chunk");
+  else if (*ar->what == 'C') {
+    if (compat53_pushglobalfuncname(L, ar)) {
+      lua_pushfstring(L, "function " LUA_QS, lua_tostring(L, -1));
+      lua_remove(L, -2);  /* remove name */
+    }
+    else
+      lua_pushliteral(L, "?");
+  }
+  else
+    lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined);
+}
+
+#define COMPAT53_LEVELS1 12  /* size of the first part of the stack */
+#define COMPAT53_LEVELS2 10  /* size of the second part of the stack */
+
+COMPAT53_API void luaL_traceback (lua_State *L, lua_State *L1,
+                                  const char *msg, int level) {
+  lua_Debug ar;
+  int top = lua_gettop(L);
+  int numlevels = compat53_countlevels(L1);
+  int mark = (numlevels > COMPAT53_LEVELS1 + COMPAT53_LEVELS2) ? COMPAT53_LEVELS1 : 0;
+  if (msg) lua_pushfstring(L, "%s\n", msg);
+  lua_pushliteral(L, "stack traceback:");
+  while (lua_getstack(L1, level++, &ar)) {
+    if (level == mark) {  /* too many levels? */
+      lua_pushliteral(L, "\n\t...");  /* add a '...' */
+      level = numlevels - COMPAT53_LEVELS2;  /* and skip to last ones */
+    }
+    else {
+      lua_getinfo(L1, "Slnt", &ar);
+      lua_pushfstring(L, "\n\t%s:", ar.short_src);
+      if (ar.currentline > 0)
+        lua_pushfstring(L, "%d:", ar.currentline);
+      lua_pushliteral(L, " in ");
+      compat53_pushfuncname(L, &ar);
+      lua_concat(L, lua_gettop(L) - top);
+    }
+  }
+  lua_concat(L, lua_gettop(L) - top);
+}
+
+
+COMPAT53_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
+  int en = errno;  /* calls to Lua API may change this value */
+  if (stat) {
+    lua_pushboolean(L, 1);
+    return 1;
+  }
+  else {
+    lua_pushnil(L);
+    if (fname)
+      lua_pushfstring(L, "%s: %s", fname, strerror(en));
+    else
+      lua_pushstring(L, strerror(en));
+    lua_pushnumber(L, (lua_Number)en);
+    return 3;
+  }
+}
+
+
+#if !defined(l_inspectstat) && \
+    (defined(unix) || defined(__unix) || defined(__unix__) || \
+     defined(__TOS_AIX__) || defined(_SYSTYPE_BSD) || \
+     (defined(__APPLE__) && defined(__MACH__)))
+/* some form of unix; check feature macros in unistd.h for details */
+#  include <unistd.h>
+/* check posix version; the relevant include files and macros probably
+ * were available before 2001, but I'm not sure */
+#  if defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L
+#    include <sys/wait.h>
+#    define l_inspectstat(stat,what) \
+  if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \
+  else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; }
+#  endif
+#endif
+
+/* provide default (no-op) version */
+#if !defined(l_inspectstat)
+#  define l_inspectstat(stat,what) ((void)0)
+#endif
+
+
+COMPAT53_API int luaL_execresult (lua_State *L, int stat) {
+  const char *what = "exit";
+  if (stat == -1)
+    return luaL_fileresult(L, 0, NULL);
+  else {
+    l_inspectstat(stat, what);
+    if (*what == 'e' && stat == 0)
+      lua_pushboolean(L, 1);
+    else
+      lua_pushnil(L);
+    lua_pushstring(L, what);
+    lua_pushinteger(L, stat);
+    return 3;
+  }
+}
+
+
+COMPAT53_API void luaL_buffinit (lua_State *L, luaL_Buffer_53 *B) {
+  /* make it crash if used via pointer to a 5.1-style luaL_Buffer */
+  B->b.p = NULL;
+  B->b.L = NULL;
+  B->b.lvl = 0;
+  /* reuse the buffer from the 5.1-style luaL_Buffer though! */
+  B->ptr = B->b.buffer;
+  B->capacity = LUAL_BUFFERSIZE;
+  B->nelems = 0;
+  B->L2 = L;
+}
+
+
+COMPAT53_API char *luaL_prepbuffsize (luaL_Buffer_53 *B, size_t s) {
+  if (B->capacity - B->nelems < s) { /* needs to grow */
+    char* newptr = NULL;
+    size_t newcap = B->capacity * 2;
+    if (newcap - B->nelems < s)
+      newcap = B->nelems + s;
+    if (newcap < B->capacity) /* overflow */
+      luaL_error(B->L2, "buffer too large");
+    newptr = (char*)lua_newuserdata(B->L2, newcap);
+    memcpy(newptr, B->ptr, B->nelems);
+    if (B->ptr != B->b.buffer)
+      lua_replace(B->L2, -2); /* remove old buffer */
+    B->ptr = newptr;
+    B->capacity = newcap;
+  }
+  return B->ptr+B->nelems;
+}
+
+
+COMPAT53_API void luaL_addlstring (luaL_Buffer_53 *B, const char *s, size_t l) {
+  memcpy(luaL_prepbuffsize(B, l), s, l);
+  luaL_addsize(B, l);
+}
+
+
+COMPAT53_API void luaL_addvalue (luaL_Buffer_53 *B) {
+  size_t len = 0;
+  const char *s = lua_tolstring(B->L2, -1, &len);
+  if (!s)
+    luaL_error(B->L2, "cannot convert value to string");
+  if (B->ptr != B->b.buffer)
+    lua_insert(B->L2, -2); /* userdata buffer must be at stack top */
+  luaL_addlstring(B, s, len);
+  lua_remove(B->L2, B->ptr != B->b.buffer ? -2 : -1);
+}
+
+
+void luaL_pushresult (luaL_Buffer_53 *B) {
+  lua_pushlstring(B->L2, B->ptr, B->nelems);
+  if (B->ptr != B->b.buffer)
+    lua_replace(B->L2, -2); /* remove userdata buffer */
+}
+
+
+#endif /* Lua 5.1 */
+
+
+
+/* definitions for Lua 5.1 and Lua 5.2 */
+#if defined( LUA_VERSION_NUM ) && LUA_VERSION_NUM <= 502
+
+
+COMPAT53_API int lua_geti (lua_State *L, int index, lua_Integer i) {
+  index = lua_absindex(L, index);
+  lua_pushinteger(L, i);
+  lua_gettable(L, index);
+  return lua_type(L, -1);
+}
+
+
+COMPAT53_API int lua_isinteger (lua_State *L, int index) {
+  if (lua_type(L, index) == LUA_TNUMBER) {
+    lua_Number n = lua_tonumber(L, index);
+    lua_Integer i = lua_tointeger(L, index);
+    if (i == n)
+      return 1;
+  }
+  return 0;
+}
+
+
+static void compat53_reverse (lua_State *L, int a, int b) {
+  for (; a < b; ++a, --b) {
+    lua_pushvalue(L, a);
+    lua_pushvalue(L, b);
+    lua_replace(L, a);
+    lua_replace(L, b);
+  }
+}
+
+
+COMPAT53_API void lua_rotate (lua_State *L, int idx, int n) {
+  int n_elems = 0;
+  idx = lua_absindex(L, idx);
+  n_elems = lua_gettop(L)-idx+1;
+  if (n < 0)
+    n += n_elems;
+  if ( n > 0 && n < n_elems) {
+    luaL_checkstack(L, 2, "not enough stack slots available");
+    n = n_elems - n;
+    compat53_reverse(L, idx, idx+n-1);
+    compat53_reverse(L, idx+n, idx+n_elems-1);
+    compat53_reverse(L, idx, idx+n_elems-1);
+  }
+}
+
+
+COMPAT53_API void lua_seti (lua_State *L, int index, lua_Integer i) {
+  luaL_checkstack(L, 1, "not enough stack slots available");
+  index = lua_absindex(L, index);
+  lua_pushinteger(L, i);
+  lua_insert(L, -2);
+  lua_settable(L, index);
+}
+
+
+#if !defined(lua_str2number)
+#  define lua_str2number(s, p)  strtod((s), (p))
+#endif
+
+COMPAT53_API size_t lua_stringtonumber (lua_State *L, const char *s) {
+  char* endptr;
+  lua_Number n = lua_str2number(s, &endptr);
+  if (endptr != s) {
+    while (*endptr != '\0' && isspace((unsigned char)*endptr))
+      ++endptr;
+    if (*endptr == '\0') {
+      lua_pushnumber(L, n);
+      return endptr - s + 1;
+    }
+  }
+  return 0;
+}
+
+
+COMPAT53_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
+  if (!luaL_callmeta(L, idx, "__tostring")) {
+    int t = lua_type(L, idx), tt = 0;
+    char const* name = NULL;
+    switch (t) {
+      case LUA_TNIL:
+        lua_pushliteral(L, "nil");
+        break;
+      case LUA_TSTRING:
+      case LUA_TNUMBER:
+        lua_pushvalue(L, idx);
+        break;
+      case LUA_TBOOLEAN:
+        if (lua_toboolean(L, idx))
+          lua_pushliteral(L, "true");
+        else
+          lua_pushliteral(L, "false");
+        break;
+      default:
+        tt = luaL_getmetafield(L, idx, "__name");
+        name = (tt == LUA_TSTRING) ? lua_tostring(L, -1) : lua_typename(L, t);
+        lua_pushfstring(L, "%s: %p", name, lua_topointer(L, idx));
+        if (tt != LUA_TNIL)
+          lua_replace(L, -2);
+        break;
+    }
+  } else {
+    if (!lua_isstring(L, -1))
+      luaL_error(L, "'__tostring' must return a string");
+  }
+  return lua_tolstring(L, -1, len);
+}
+
+
+COMPAT53_API void luaL_requiref (lua_State *L, const char *modname,
+                                 lua_CFunction openf, int glb) {
+  luaL_checkstack(L, 3, "not enough stack slots available");
+  luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
+  if (lua_getfield(L, -1, modname) == LUA_TNIL) {
+    lua_pop(L, 1);
+    lua_pushcfunction(L, openf);
+    lua_pushstring(L, modname);
+    lua_call(L, 1, 1);
+    lua_pushvalue(L, -1);
+    lua_setfield(L, -3, modname);
+  }
+  if (glb) {
+    lua_pushvalue(L, -1);
+    lua_setglobal(L, modname);
+  }
+  lua_replace(L, -2);
+}
+
+
+#endif /* Lua 5.1 and 5.2 */
+
+
+#endif /* COMPAT53_C_ */
+
+
+/*********************************************************************
+* This file contains parts of Lua 5.2's and Lua 5.3's source code:
+*
+* Copyright (C) 1994-2014 Lua.org, PUC-Rio.
+*
+* Permission is hereby granted, free of charge, to any person obtaining
+* a copy of this software and associated documentation files (the
+* "Software"), to deal in the Software without restriction, including
+* without limitation the rights to use, copy, modify, merge, publish,
+* distribute, sublicense, and/or sell copies of the Software, and to
+* permit persons to whom the Software is furnished to do so, subject to
+* the following conditions:
+*
+* The above copyright notice and this permission notice shall be
+* included in all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*********************************************************************/
+
diff --git a/vendor/compat53/c-api/compat-5.3.h b/vendor/compat53/c-api/compat-5.3.h
new file mode 100644
index 0000000..bee77a1
--- /dev/null
+++ b/vendor/compat53/c-api/compat-5.3.h
@@ -0,0 +1,388 @@
+#ifndef COMPAT53_H_
+#define COMPAT53_H_
+
+#include <stddef.h>
+#include <limits.h>
+#include <string.h>
+#if defined(__cplusplus) && !defined(COMPAT53_LUA_CPP)
+extern "C" {
+#endif
+#include <lua.h>
+#include <lauxlib.h>
+#if defined(__cplusplus) && !defined(COMPAT53_LUA_CPP)
+}
+#endif
+
+
+#if defined(COMPAT53_PREFIX)
+/* - change the symbol names of functions to avoid linker conflicts
+ * - compat-5.3.c needs to be compiled (and linked) separately
+ */
+#  if !defined(COMPAT53_API)
+#    define COMPAT53_API extern
+#  endif
+#  undef COMPAT53_INCLUDE_SOURCE
+#else /* COMPAT53_PREFIX */
+/* - make all functions static and include the source.
+ * - compat-5.3.c doesn't need to be compiled (and linked) separately
+ */
+#  define COMPAT53_PREFIX compat53
+#  undef COMPAT53_API
+#  if defined(__GNUC__) || defined(__clang__)
+#    define COMPAT53_API __attribute__((__unused__)) static
+#  else
+#    define COMPAT53_API static
+#  endif
+#  define COMPAT53_INCLUDE_SOURCE
+#endif /* COMPAT53_PREFIX */
+
+#define COMPAT53_CONCAT_HELPER(a, b) a##b
+#define COMPAT53_CONCAT(a, b) COMPAT53_CONCAT_HELPER(a, b)
+
+
+
+/* declarations for Lua 5.1 */
+#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM == 501
+
+/* XXX not implemented:
+ * lua_arith (new operators)
+ * lua_upvalueid
+ * lua_upvaluejoin
+ * lua_version
+ * lua_yieldk
+ * luaL_loadbufferx
+ * luaL_loadfilex
+ */
+
+#ifndef LUA_OK
+#  define LUA_OK 0
+#endif
+#ifndef LUA_OPADD
+#  define LUA_OPADD 0
+#endif
+#ifndef LUA_OPSUB
+#  define LUA_OPSUB 1
+#endif
+#ifndef LUA_OPMUL
+#  define LUA_OPMUL 2
+#endif
+#ifndef LUA_OPDIV
+#  define LUA_OPDIV 3
+#endif
+#ifndef LUA_OPMOD
+#  define LUA_OPMOD 4
+#endif
+#ifndef LUA_OPPOW
+#  define LUA_OPPOW 5
+#endif
+#ifndef LUA_OPUNM
+#  define LUA_OPUNM 6
+#endif
+#ifndef LUA_OPEQ
+#  define LUA_OPEQ 0
+#endif
+#ifndef LUA_OPLT
+#  define LUA_OPLT 1
+#endif
+#ifndef LUA_OPLE
+#  define LUA_OPLE 2
+#endif
+
+typedef size_t lua_Unsigned;
+
+typedef struct luaL_Buffer_53 {
+  luaL_Buffer b; /* make incorrect code crash! */
+  char *ptr;
+  size_t nelems;
+  size_t capacity;
+  lua_State *L2;
+} luaL_Buffer_53;
+#define luaL_Buffer luaL_Buffer_53
+
+#define lua_absindex COMPAT53_CONCAT(COMPAT53_PREFIX, _absindex)
+COMPAT53_API int lua_absindex (lua_State *L, int i);
+
+#define lua_arith COMPAT53_CONCAT(COMPAT53_PREFIX, _arith)
+COMPAT53_API void lua_arith (lua_State *L, int op);
+
+#define lua_compare COMPAT53_CONCAT(COMPAT53_PREFIX, _compare)
+COMPAT53_API int lua_compare (lua_State *L, int idx1, int idx2, int op);
+
+#define lua_copy COMPAT53_CONCAT(COMPAT53_PREFIX, _copy)
+COMPAT53_API void lua_copy (lua_State *L, int from, int to);
+
+#define lua_getuservalue(L, i) \
+  (lua_getfenv((L), (i)), lua_type((L), -1))
+#define lua_setuservalue(L, i) \
+  (luaL_checktype((L), -1, LUA_TTABLE), lua_setfenv((L), (i)))
+
+#define lua_len COMPAT53_CONCAT(COMPAT53_PREFIX, _len)
+COMPAT53_API void lua_len (lua_State *L, int i);
+
+#define lua_pushstring(L, s) \
+  (lua_pushstring((L), (s)), lua_tostring((L), -1))
+
+#define lua_pushlstring(L, s, len) \
+  ((((len) == 0) ? lua_pushlstring((L), "", 0) : lua_pushlstring((L), (s), (len))), lua_tostring((L), -1))
+
+#ifndef luaL_newlibtable
+#  define luaL_newlibtable(L, l) \
+  (lua_createtable((L), 0, sizeof((l))/sizeof(*(l))-1))
+#endif
+#ifndef luaL_newlib
+#  define luaL_newlib(L, l) \
+  (luaL_newlibtable((L), (l)), luaL_register((L), NULL, (l)))
+#endif
+
+#define lua_pushglobaltable(L) \
+  lua_pushvalue((L), LUA_GLOBALSINDEX)
+
+#define lua_rawgetp COMPAT53_CONCAT(COMPAT53_PREFIX, _rawgetp)
+COMPAT53_API int lua_rawgetp (lua_State *L, int i, const void *p);
+
+#define lua_rawsetp COMPAT53_CONCAT(COMPAT53_PREFIX, _rawsetp)
+COMPAT53_API void lua_rawsetp(lua_State *L, int i, const void *p);
+
+#define lua_rawlen(L, i) lua_objlen((L), (i))
+
+#define lua_tointegerx COMPAT53_CONCAT(COMPAT53_PREFIX, _tointegerx)
+COMPAT53_API lua_Integer lua_tointegerx (lua_State *L, int i, int *isnum);
+
+#define lua_tonumberx COMPAT53_CONCAT(COMPAT53_PREFIX, _tonumberx)
+COMPAT53_API lua_Number lua_tonumberx (lua_State *L, int i, int *isnum);
+
+#define luaL_checkversion COMPAT53_CONCAT(COMPAT53_PREFIX, L_checkversion)
+COMPAT53_API void luaL_checkversion (lua_State *L);
+
+#define luaL_checkstack COMPAT53_CONCAT(COMPAT53_PREFIX, L_checkstack_53)
+COMPAT53_API void luaL_checkstack (lua_State *L, int sp, const char *msg);
+
+#define luaL_getsubtable COMPAT53_CONCAT(COMPAT53_PREFIX, L_getsubtable)
+COMPAT53_API int luaL_getsubtable (lua_State* L, int i, const char *name);
+
+#define luaL_len COMPAT53_CONCAT(COMPAT53_PREFIX, L_len)
+COMPAT53_API lua_Integer luaL_len (lua_State *L, int i);
+
+#define luaL_setfuncs COMPAT53_CONCAT(COMPAT53_PREFIX, L_setfuncs)
+COMPAT53_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup);
+
+#define luaL_setmetatable COMPAT53_CONCAT(COMPAT53_PREFIX, L_setmetatable)
+COMPAT53_API void luaL_setmetatable (lua_State *L, const char *tname);
+
+#define luaL_testudata COMPAT53_CONCAT(COMPAT53_PREFIX, L_testudata)
+COMPAT53_API void *luaL_testudata (lua_State *L, int i, const char *tname);
+
+#define luaL_traceback COMPAT53_CONCAT(COMPAT53_PREFIX, L_traceback)
+COMPAT53_API void luaL_traceback (lua_State *L, lua_State *L1, const char *msg, int level);
+
+#define luaL_fileresult COMPAT53_CONCAT(COMPAT53_PREFIX, L_fileresult)
+COMPAT53_API int luaL_fileresult (lua_State *L, int stat, const char *fname);
+
+#define luaL_execresult COMPAT53_CONCAT(COMPAT53_PREFIX, L_execresult)
+COMPAT53_API int luaL_execresult (lua_State *L, int stat);
+
+#define lua_callk(L, na, nr, ctx, cont) \
+  ((void)(ctx), (void)(cont), lua_call((L), (na), (nr)))
+#define lua_pcallk(L, na, nr, err, ctx, cont) \
+  ((void)(ctx), (void)(cont), lua_pcall((L), (na), (nr), (err)))
+
+#define luaL_buffinit COMPAT53_CONCAT(COMPAT53_PREFIX, _buffinit_53)
+COMPAT53_API void luaL_buffinit (lua_State *L, luaL_Buffer_53 *B);
+
+#define luaL_prepbuffsize COMPAT53_CONCAT(COMPAT53_PREFIX, _prepbufsize_53)
+COMPAT53_API char *luaL_prepbuffsize (luaL_Buffer_53 *B, size_t s);
+
+#define luaL_addlstring COMPAT53_CONCAT(COMPAT53_PREFIX, _addlstring_53)
+COMPAT53_API void luaL_addlstring (luaL_Buffer_53 *B, const char *s, size_t l);
+
+#define luaL_addvalue COMPAT53_CONCAT(COMPAT53_PREFIX, _addvalue_53)
+COMPAT53_API void luaL_addvalue (luaL_Buffer_53 *B);
+
+#define luaL_pushresult COMPAT53_CONCAT(COMPAT53_PREFIX, _pushresult_53)
+COMPAT53_API void luaL_pushresult (luaL_Buffer_53 *B);
+
+#undef luaL_buffinitsize
+#define luaL_buffinitsize(L, B, s) \
+  (luaL_buffinit((L), (B)), luaL_prepbuffsize((B), (s)))
+
+#undef luaL_prepbuffer
+#define luaL_prepbuffer(B) \
+  luaL_prepbuffsize((B), LUAL_BUFFERSIZE)
+
+#undef luaL_addchar
+#define luaL_addchar(B, c) \
+  ((void)((B)->nelems < (B)->capacity || luaL_prepbuffsize((B), 1)), \
+   ((B)->ptr[(B)->nelems++] = (c)))
+
+#undef luaL_addsize
+#define luaL_addsize(B, s) \
+  ((B)->nelems += (s))
+
+#undef luaL_addstring
+#define luaL_addstring(B, s) \
+  luaL_addlstring((B), (s), strlen((s)))
+
+#undef luaL_pushresultsize
+#define luaL_pushresultsize(B, s) \
+  (luaL_addsize((B), (s)), luaL_pushresult((B)))
+
+#if defined(LUA_COMPAT_APIINTCASTS)
+#define lua_pushunsigned(L, n) \
+  lua_pushinteger((L), (lua_Integer)(n))
+#define lua_tounsignedx(L, i, is) \
+  ((lua_Unsigned)lua_tointegerx((L), (i), (is)))
+#define lua_tounsigned(L, i) \
+  lua_tounsignedx((L), (i), NULL)
+#define luaL_checkunsigned(L, a) \
+  ((lua_Unsigned)luaL_checkinteger((L), (a)))
+#define luaL_optunsigned(L, a, d) \
+  ((lua_Unsigned)luaL_optinteger((L), (a), (lua_Integer)(d)))
+#endif
+
+#endif /* Lua 5.1 only */
+
+
+
+/* declarations for Lua 5.1 and 5.2 */
+#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM <= 502
+
+typedef int lua_KContext;
+
+typedef int (*lua_KFunction)(lua_State *L, int status, lua_KContext ctx);
+
+#define lua_dump(L, w, d, s) \
+  ((void)(s), lua_dump((L), (w), (d)))
+
+#define lua_getfield(L, i, k) \
+  (lua_getfield((L), (i), (k)), lua_type((L), -1))
+
+#define lua_gettable(L, i) \
+  (lua_gettable((L), (i)), lua_type((L), -1))
+
+#define lua_geti COMPAT53_CONCAT(COMPAT53_PREFIX, _geti)
+COMPAT53_API int lua_geti (lua_State *L, int index, lua_Integer i);
+
+#define lua_isinteger COMPAT53_CONCAT(COMPAT53_PREFIX, _isinteger)
+COMPAT53_API int lua_isinteger (lua_State *L, int index);
+
+#define lua_numbertointeger(n, p) \
+  ((*(p) = (lua_Integer)(n)), 1)
+
+#define lua_rawget(L, i) \
+  (lua_rawget((L), (i)), lua_type((L), -1))
+
+#define lua_rawgeti(L, i, n) \
+  (lua_rawgeti((L), (i), (n)), lua_type((L), -1))
+
+#define lua_rotate COMPAT53_CONCAT(COMPAT53_PREFIX, _rotate)
+COMPAT53_API void lua_rotate (lua_State *L, int idx, int n);
+
+#define lua_seti COMPAT53_CONCAT(COMPAT53_PREFIX, _seti)
+COMPAT53_API void lua_seti (lua_State *L, int index, lua_Integer i);
+
+#define lua_stringtonumber COMPAT53_CONCAT(COMPAT53_PREFIX, _stringtonumber)
+COMPAT53_API size_t lua_stringtonumber (lua_State *L, const char *s);
+
+#define luaL_tolstring COMPAT53_CONCAT(COMPAT53_PREFIX, L_tolstring)
+COMPAT53_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len);
+
+#define luaL_getmetafield(L, o, e) \
+  (luaL_getmetafield((L), (o), (e)) ? lua_type((L), -1) : LUA_TNIL)
+
+#define luaL_newmetatable(L, tn) \
+  (luaL_newmetatable((L), (tn)) ? (lua_pushstring((L), (tn)), lua_setfield((L), -2, "__name"), 1) : 0)
+
+#define luaL_requiref COMPAT53_CONCAT(COMPAT53_PREFIX, L_requiref_53)
+COMPAT53_API void luaL_requiref (lua_State *L, const char *modname,
+                                 lua_CFunction openf, int glb );
+
+#endif /* Lua 5.1 and Lua 5.2 */
+
+
+
+/* declarations for Lua 5.2 */
+#if defined(LUA_VERSION_NUM) && LUA_VERSION_NUM == 502
+
+/* XXX not implemented:
+ * lua_isyieldable
+ * lua_getextraspace
+ * lua_arith (new operators)
+ * lua_pushfstring (new formats)
+ */
+
+#define lua_getglobal(L, n) \
+  (lua_getglobal((L), (n)), lua_type((L), -1))
+
+#define lua_getuservalue(L, i) \
+  (lua_getuservalue((L), (i)), lua_type((L), -1))
+
+#define lua_pushlstring(L, s, len) \
+  (((len) == 0) ? lua_pushlstring((L), "", 0) : lua_pushlstring((L), (s), (len)))
+
+#define lua_rawgetp(L, i, p) \
+  (lua_rawgetp((L), (i), (p)), lua_type((L), -1))
+
+#define LUA_KFUNCTION(_name) \
+  static int (_name)(lua_State *L, int status, lua_KContext ctx); \
+  static int (_name ## _52)(lua_State *L) { \
+    lua_KContext ctx; \
+    int status = lua_getctx(L, &ctx); \
+    return (_name)(L, status, ctx); \
+  } \
+  static int (_name)(lua_State *L, int status, lua_KContext ctx)
+
+#define lua_pcallk(L, na, nr, err, ctx, cont) \
+  lua_pcallk((L), (na), (nr), (err), (ctx), cont ## _52)
+
+#define lua_callk(L, na, nr, ctx, cont) \
+  lua_callk((L), (na), (nr), (ctx), cont ## _52)
+
+#define lua_yieldk(L, nr, ctx, cont) \
+  lua_yieldk((L), (nr), (ctx), cont ## _52)
+
+#ifdef lua_call
+#  undef lua_call
+#  define lua_call(L, na, nr) \
+  (lua_callk)((L), (na), (nr), 0, NULL)
+#endif
+
+#ifdef lua_pcall
+#  undef lua_pcall
+#  define lua_pcall(L, na, nr, err) \
+  (lua_pcallk)((L), (na), (nr), (err), 0, NULL)
+#endif
+
+#ifdef lua_yield
+#  undef lua_yield
+#  define lua_yield(L, nr) \
+  (lua_yieldk)((L), (nr), 0, NULL)
+#endif
+
+#endif /* Lua 5.2 only */
+
+
+
+/* other Lua versions */
+#if !defined(LUA_VERSION_NUM) || LUA_VERSION_NUM < 501 || LUA_VERSION_NUM > 503
+
+#  error "unsupported Lua version (i.e. not Lua 5.1, 5.2, or 5.3)"
+
+#endif /* other Lua versions except 5.1, 5.2, and 5.3 */
+
+
+
+/* helper macro for defining continuation functions (for every version
+ * *except* Lua 5.2) */
+#ifndef LUA_KFUNCTION
+#define LUA_KFUNCTION(_name) \
+  static int (_name)(lua_State *L, int status, lua_KContext ctx)
+#endif
+
+
+#if defined(COMPAT53_INCLUDE_SOURCE)
+#  include "compat-5.3.c"
+#endif
+
+
+#endif /* COMPAT53_H_ */
+