[redis.git] / deps / lua / src / ldblib.c

/*
** $Id: ldblib.c,v 1.104.1.3 2008/01/21 13:11:21 roberto Exp $
** Interface from Lua to its debug API
** See Copyright Notice in lua.h
*/


#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define ldblib_c
#define LUA_LIB

#include "lua.h"

#include "lauxlib.h"
#include "lualib.h"


static int db_getregistry (lua_State *L) {
  lua_pushvalue(L, LUA_REGISTRYINDEX);
  return 1;
}


static int db_getmetatable (lua_State *L) {
  luaL_checkany(L, 1);
  if (!lua_getmetatable(L, 1)) {
    lua_pushnil(L);  /* no metatable */
  }
  return 1;
}


static int db_setmetatable (lua_State *L) {
  int t = lua_type(L, 2);
  luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
                    "nil or table expected");
  lua_settop(L, 2);
  lua_pushboolean(L, lua_setmetatable(L, 1));
  return 1;
}


static int db_getfenv (lua_State *L) {
  lua_getfenv(L, 1);
  return 1;
}


static int db_setfenv (lua_State *L) {
  luaL_checktype(L, 2, LUA_TTABLE);
  lua_settop(L, 2);
  if (lua_setfenv(L, 1) == 0)
    luaL_error(L, LUA_QL("setfenv")
                  " cannot change environment of given object");
  return 1;
}


static void settabss (lua_State *L, const char *i, const char *v) {
  lua_pushstring(L, v);
  lua_setfield(L, -2, i);
}


static void settabsi (lua_State *L, const char *i, int v) {
  lua_pushinteger(L, v);
  lua_setfield(L, -2, i);
}


static lua_State *getthread (lua_State *L, int *arg) {
  if (lua_isthread(L, 1)) {
    *arg = 1;
    return lua_tothread(L, 1);
  }
  else {
    *arg = 0;
    return L;
  }
}


static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) {
  if (L == L1) {
    lua_pushvalue(L, -2);
    lua_remove(L, -3);
  }
  else
    lua_xmove(L1, L, 1);
  lua_setfield(L, -2, fname);
}


static int db_getinfo (lua_State *L) {
  lua_Debug ar;
  int arg;
  lua_State *L1 = getthread(L, &arg);
  const char *options = luaL_optstring(L, arg+2, "flnSu");
  if (lua_isnumber(L, arg+1)) {
    if (!lua_getstack(L1, (int)lua_tointeger(L, arg+1), &ar)) {
      lua_pushnil(L);  /* level out of range */
      return 1;
    }
  }
  else if (lua_isfunction(L, arg+1)) {
    lua_pushfstring(L, ">%s", options);
    options = lua_tostring(L, -1);
    lua_pushvalue(L, arg+1);
    lua_xmove(L, L1, 1);
  }
  else
    return luaL_argerror(L, arg+1, "function or level expected");
  if (!lua_getinfo(L1, options, &ar))
    return luaL_argerror(L, arg+2, "invalid option");
  lua_createtable(L, 0, 2);
  if (strchr(options, 'S')) {
    settabss(L, "source", ar.source);
    settabss(L, "short_src", ar.short_src);
    settabsi(L, "linedefined", ar.linedefined);
    settabsi(L, "lastlinedefined", ar.lastlinedefined);
    settabss(L, "what", ar.what);
  }
  if (strchr(options, 'l'))
    settabsi(L, "currentline", ar.currentline);
  if (strchr(options, 'u'))
    settabsi(L, "nups", ar.nups);
  if (strchr(options, 'n')) {
    settabss(L, "name", ar.name);
    settabss(L, "namewhat", ar.namewhat);
  }
  if (strchr(options, 'L'))
    treatstackoption(L, L1, "activelines");
  if (strchr(options, 'f'))
    treatstackoption(L, L1, "func");
  return 1;  /* return table */
}
    

static int db_getlocal (lua_State *L) {
  int arg;
  lua_State *L1 = getthread(L, &arg);
  lua_Debug ar;
  const char *name;
  if (!lua_getstack(L1, luaL_checkint(L, arg+1), &ar))  /* out of range? */
    return luaL_argerror(L, arg+1, "level out of range");
  name = lua_getlocal(L1, &ar, luaL_checkint(L, arg+2));
  if (name) {
    lua_xmove(L1, L, 1);
    lua_pushstring(L, name);
    lua_pushvalue(L, -2);
    return 2;
  }
  else {
    lua_pushnil(L);
    return 1;
  }
}


static int db_setlocal (lua_State *L) {
  int arg;
  lua_State *L1 = getthread(L, &arg);
  lua_Debug ar;
  if (!lua_getstack(L1, luaL_checkint(L, arg+1), &ar))  /* out of range? */
    return luaL_argerror(L, arg+1, "level out of range");
  luaL_checkany(L, arg+3);
  lua_settop(L, arg+3);
  lua_xmove(L, L1, 1);
  lua_pushstring(L, lua_setlocal(L1, &ar, luaL_checkint(L, arg+2)));
  return 1;
}


static int auxupvalue (lua_State *L, int get) {
  const char *name;
  int n = luaL_checkint(L, 2);
  luaL_checktype(L, 1, LUA_TFUNCTION);
  if (lua_iscfunction(L, 1)) return 0;  /* cannot touch C upvalues from Lua */
  name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
  if (name == NULL) return 0;
  lua_pushstring(L, name);
  lua_insert(L, -(get+1));
  return get + 1;
}


static int db_getupvalue (lua_State *L) {
  return auxupvalue(L, 1);
}


static int db_setupvalue (lua_State *L) {
  luaL_checkany(L, 3);
  return auxupvalue(L, 0);
}


static const char KEY_HOOK = 'h';


static void hookf (lua_State *L, lua_Debug *ar) {
  static const char *const hooknames[] =
    {"call", "return", "line", "count", "tail return"};
  lua_pushlightuserdata(L, (void *)&KEY_HOOK);
  lua_rawget(L, LUA_REGISTRYINDEX);
  lua_pushlightuserdata(L, L);
  lua_rawget(L, -2);
  if (lua_isfunction(L, -1)) {
    lua_pushstring(L, hooknames[(int)ar->event]);
    if (ar->currentline >= 0)
      lua_pushinteger(L, ar->currentline);
    else lua_pushnil(L);
    lua_assert(lua_getinfo(L, "lS", ar));
    lua_call(L, 2, 0);
  }
}


static int makemask (const char *smask, int count) {
  int mask = 0;
  if (strchr(smask, 'c')) mask |= LUA_MASKCALL;
  if (strchr(smask, 'r')) mask |= LUA_MASKRET;
  if (strchr(smask, 'l')) mask |= LUA_MASKLINE;
  if (count > 0) mask |= LUA_MASKCOUNT;
  return mask;
}


static char *unmakemask (int mask, char *smask) {
  int i = 0;
  if (mask & LUA_MASKCALL) smask[i++] = 'c';
  if (mask & LUA_MASKRET) smask[i++] = 'r';
  if (mask & LUA_MASKLINE) smask[i++] = 'l';
  smask[i] = '\0';
  return smask;
}


static void gethooktable (lua_State *L) {
  lua_pushlightuserdata(L, (void *)&KEY_HOOK);
  lua_rawget(L, LUA_REGISTRYINDEX);
  if (!lua_istable(L, -1)) {
    lua_pop(L, 1);
    lua_createtable(L, 0, 1);
    lua_pushlightuserdata(L, (void *)&KEY_HOOK);
    lua_pushvalue(L, -2);
    lua_rawset(L, LUA_REGISTRYINDEX);
  }
}


static int db_sethook (lua_State *L) {
  int arg, mask, count;
  lua_Hook func;
  lua_State *L1 = getthread(L, &arg);
  if (lua_isnoneornil(L, arg+1)) {
    lua_settop(L, arg+1);
    func = NULL; mask = 0; count = 0;  /* turn off hooks */
  }
  else {
    const char *smask = luaL_checkstring(L, arg+2);
    luaL_checktype(L, arg+1, LUA_TFUNCTION);
    count = luaL_optint(L, arg+3, 0);
    func = hookf; mask = makemask(smask, count);
  }
  gethooktable(L);
  lua_pushlightuserdata(L, L1);
  lua_pushvalue(L, arg+1);
  lua_rawset(L, -3);  /* set new hook */
  lua_pop(L, 1);  /* remove hook table */
  lua_sethook(L1, func, mask, count);  /* set hooks */
  return 0;
}


static int db_gethook (lua_State *L) {
  int arg;
  lua_State *L1 = getthread(L, &arg);
  char buff[5];
  int mask = lua_gethookmask(L1);
  lua_Hook hook = lua_gethook(L1);
  if (hook != NULL && hook != hookf)  /* external hook? */
    lua_pushliteral(L, "external hook");
  else {
    gethooktable(L);
    lua_pushlightuserdata(L, L1);
    lua_rawget(L, -2);   /* get hook */
    lua_remove(L, -2);  /* remove hook table */
  }
  lua_pushstring(L, unmakemask(mask, buff));
  lua_pushinteger(L, lua_gethookcount(L1));
  return 3;
}


static int db_debug (lua_State *L) {
  for (;;) {
    char buffer[250];
    fputs("lua_debug> ", stderr);
    if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
        strcmp(buffer, "cont\n") == 0)
      return 0;
    if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
        lua_pcall(L, 0, 0, 0)) {
      fputs(lua_tostring(L, -1), stderr);
      fputs("\n", stderr);
    }
    lua_settop(L, 0);  /* remove eventual returns */
  }
}


#define LEVELS1	12	/* size of the first part of the stack */
#define LEVELS2	10	/* size of the second part of the stack */

static int db_errorfb (lua_State *L) {
  int level;
  int firstpart = 1;  /* still before eventual `...' */
  int arg;
  lua_State *L1 = getthread(L, &arg);
  lua_Debug ar;
  if (lua_isnumber(L, arg+2)) {
    level = (int)lua_tointeger(L, arg+2);
    lua_pop(L, 1);
  }
  else
    level = (L == L1) ? 1 : 0;  /* level 0 may be this own function */
  if (lua_gettop(L) == arg)
    lua_pushliteral(L, "");
  else if (!lua_isstring(L, arg+1)) return 1;  /* message is not a string */
  else lua_pushliteral(L, "\n");
  lua_pushliteral(L, "stack traceback:");
  while (lua_getstack(L1, level++, &ar)) {
    if (level > LEVELS1 && firstpart) {
      /* no more than `LEVELS2' more levels? */
      if (!lua_getstack(L1, level+LEVELS2, &ar))
        level--;  /* keep going */
      else {
        lua_pushliteral(L, "\n\t...");  /* too many levels */
        while (lua_getstack(L1, level+LEVELS2, &ar))  /* find last levels */
          level++;
      }
      firstpart = 0;
      continue;
    }
    lua_pushliteral(L, "\n\t");
    lua_getinfo(L1, "Snl", &ar);
    lua_pushfstring(L, "%s:", ar.short_src);
    if (ar.currentline > 0)
      lua_pushfstring(L, "%d:", ar.currentline);
    if (*ar.namewhat != '\0')  /* is there a name? */
        lua_pushfstring(L, " in function " LUA_QS, ar.name);
    else {
      if (*ar.what == 'm')  /* main? */
        lua_pushfstring(L, " in main chunk");
      else if (*ar.what == 'C' || *ar.what == 't')
        lua_pushliteral(L, " ?");  /* C function or tail call */
      else
        lua_pushfstring(L, " in function <%s:%d>",
                           ar.short_src, ar.linedefined);
    }
    lua_concat(L, lua_gettop(L) - arg);
  }
  lua_concat(L, lua_gettop(L) - arg);
  return 1;
}


static const luaL_Reg dblib[] = {
  {"debug", db_debug},
  {"getfenv", db_getfenv},
  {"gethook", db_gethook},
  {"getinfo", db_getinfo},
  {"getlocal", db_getlocal},
  {"getregistry", db_getregistry},
  {"getmetatable", db_getmetatable},
  {"getupvalue", db_getupvalue},
  {"setfenv", db_setfenv},
  {"sethook", db_sethook},
  {"setlocal", db_setlocal},
  {"setmetatable", db_setmetatable},
  {"setupvalue", db_setupvalue},
  {"traceback", db_errorfb},
  {NULL, NULL}
};


LUALIB_API int luaopen_debug (lua_State *L) {
  luaL_register(L, LUA_DBLIBNAME, dblib);
  return 1;
}
Commit	Line	Data
21d3294c	1	/*
	2	** $Id: ldblib.c,v 1.104.1.3 2008/01/21 13:11:21 roberto Exp $
	3	** Interface from Lua to its debug API
	4	** See Copyright Notice in lua.h
	5	*/
	6
	7
	8	#include <stdio.h>
	9	#include <stdlib.h>
	10	#include <string.h>
	11
	12	#define ldblib_c
	13	#define LUA_LIB
	14
	15	#include "lua.h"
	16
	17	#include "lauxlib.h"
	18	#include "lualib.h"
	19
	20
	21
	22	static int db_getregistry (lua_State *L) {
	23	lua_pushvalue(L, LUA_REGISTRYINDEX);
	24	return 1;
	25	}
	26
	27
	28	static int db_getmetatable (lua_State *L) {
	29	luaL_checkany(L, 1);
	30	if (!lua_getmetatable(L, 1)) {
	31	lua_pushnil(L); /* no metatable */
	32	}
	33	return 1;
	34	}
	35
	36
	37	static int db_setmetatable (lua_State *L) {
	38	int t = lua_type(L, 2);
	39	luaL_argcheck(L, t == LUA_TNIL \|\| t == LUA_TTABLE, 2,
	40	"nil or table expected");
	41	lua_settop(L, 2);
	42	lua_pushboolean(L, lua_setmetatable(L, 1));
	43	return 1;
	44	}
	45
	46
	47	static int db_getfenv (lua_State *L) {
	48	lua_getfenv(L, 1);
	49	return 1;
	50	}
	51
	52
	53	static int db_setfenv (lua_State *L) {
	54	luaL_checktype(L, 2, LUA_TTABLE);
	55	lua_settop(L, 2);
	56	if (lua_setfenv(L, 1) == 0)
	57	luaL_error(L, LUA_QL("setfenv")
	58	" cannot change environment of given object");
	59	return 1;
	60	}
	61
	62
	63	static void settabss (lua_State L, const char i, const char *v) {
	64	lua_pushstring(L, v);
65	lua_setfield(L, -2, i);
66	}
67
68
69	static void settabsi (lua_State L, const char i, int v) {
70	lua_pushinteger(L, v);
71	lua_setfield(L, -2, i);
72	}
73
74
75	static lua_State getthread (lua_State L, int *arg) {
76	if (lua_isthread(L, 1)) {
77	*arg = 1;
78	return lua_tothread(L, 1);
79	}
80	else {
81	*arg = 0;
82	return L;
83	}
84	}
85
86
87	static void treatstackoption (lua_State L, lua_State L1, const char *fname) {
88	if (L == L1) {
89	lua_pushvalue(L, -2);
90	lua_remove(L, -3);
91	}
92	else
93	lua_xmove(L1, L, 1);
94	lua_setfield(L, -2, fname);
95	}
96
97
98	static int db_getinfo (lua_State *L) {
99	lua_Debug ar;
100	int arg;
101	lua_State *L1 = getthread(L, &arg);
102	const char *options = luaL_optstring(L, arg+2, "flnSu");
103	if (lua_isnumber(L, arg+1)) {
104	if (!lua_getstack(L1, (int)lua_tointeger(L, arg+1), &ar)) {
105	lua_pushnil(L); /* level out of range */
106	return 1;
107	}
108	}
109	else if (lua_isfunction(L, arg+1)) {
110	lua_pushfstring(L, ">%s", options);
111	options = lua_tostring(L, -1);
112	lua_pushvalue(L, arg+1);
113	lua_xmove(L, L1, 1);
114	}
115	else
116	return luaL_argerror(L, arg+1, "function or level expected");
117	if (!lua_getinfo(L1, options, &ar))
118	return luaL_argerror(L, arg+2, "invalid option");
119	lua_createtable(L, 0, 2);
120	if (strchr(options, 'S')) {
121	settabss(L, "source", ar.source);
122	settabss(L, "short_src", ar.short_src);
123	settabsi(L, "linedefined", ar.linedefined);
124	settabsi(L, "lastlinedefined", ar.lastlinedefined);
125	settabss(L, "what", ar.what);
126	}
127	if (strchr(options, 'l'))
128	settabsi(L, "currentline", ar.currentline);
129	if (strchr(options, 'u'))
130	settabsi(L, "nups", ar.nups);
131	if (strchr(options, 'n')) {
132	settabss(L, "name", ar.name);
133	settabss(L, "namewhat", ar.namewhat);
134	}
135	if (strchr(options, 'L'))
136	treatstackoption(L, L1, "activelines");
137	if (strchr(options, 'f'))
138	treatstackoption(L, L1, "func");
139	return 1; /* return table */
140	}
141
142
143	static int db_getlocal (lua_State *L) {
144	int arg;
145	lua_State *L1 = getthread(L, &arg);
146	lua_Debug ar;
147	const char *name;
148	if (!lua_getstack(L1, luaL_checkint(L, arg+1), &ar)) /* out of range? */
149	return luaL_argerror(L, arg+1, "level out of range");
150	name = lua_getlocal(L1, &ar, luaL_checkint(L, arg+2));
151	if (name) {
152	lua_xmove(L1, L, 1);
153	lua_pushstring(L, name);
154	lua_pushvalue(L, -2);
155	return 2;
156	}
157	else {
158	lua_pushnil(L);
159	return 1;
160	}
161	}
162
163
164	static int db_setlocal (lua_State *L) {
165	int arg;
166	lua_State *L1 = getthread(L, &arg);
167	lua_Debug ar;
168	if (!lua_getstack(L1, luaL_checkint(L, arg+1), &ar)) /* out of range? */
169	return luaL_argerror(L, arg+1, "level out of range");
170	luaL_checkany(L, arg+3);
171	lua_settop(L, arg+3);
172	lua_xmove(L, L1, 1);
173	lua_pushstring(L, lua_setlocal(L1, &ar, luaL_checkint(L, arg+2)));
174	return 1;
175	}
176
177
178	static int auxupvalue (lua_State *L, int get) {
179	const char *name;
180	int n = luaL_checkint(L, 2);
181	luaL_checktype(L, 1, LUA_TFUNCTION);
182	if (lua_iscfunction(L, 1)) return 0; /* cannot touch C upvalues from Lua */
183	name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
184	if (name == NULL) return 0;
185	lua_pushstring(L, name);
186	lua_insert(L, -(get+1));
187	return get + 1;
188	}
189
190
191	static int db_getupvalue (lua_State *L) {
192	return auxupvalue(L, 1);
193	}
194
195
196	static int db_setupvalue (lua_State *L) {
197	luaL_checkany(L, 3);
198	return auxupvalue(L, 0);
199	}
200
201
202
203	static const char KEY_HOOK = 'h';
204
205
206	static void hookf (lua_State L, lua_Debug ar) {
207	static const char *const hooknames[] =
208	{"call", "return", "line", "count", "tail return"};
209	lua_pushlightuserdata(L, (void *)&KEY_HOOK);
210	lua_rawget(L, LUA_REGISTRYINDEX);
211	lua_pushlightuserdata(L, L);
212	lua_rawget(L, -2);
213	if (lua_isfunction(L, -1)) {
214	lua_pushstring(L, hooknames[(int)ar->event]);
215	if (ar->currentline >= 0)
216	lua_pushinteger(L, ar->currentline);
217	else lua_pushnil(L);
218	lua_assert(lua_getinfo(L, "lS", ar));
219	lua_call(L, 2, 0);
220	}
221	}
222
223
224	static int makemask (const char *smask, int count) {
225	int mask = 0;
226	if (strchr(smask, 'c')) mask \|= LUA_MASKCALL;
227	if (strchr(smask, 'r')) mask \|= LUA_MASKRET;
228	if (strchr(smask, 'l')) mask \|= LUA_MASKLINE;
229	if (count > 0) mask \|= LUA_MASKCOUNT;
230	return mask;
231	}
232
233
234	static char unmakemask (int mask, char smask) {
235	int i = 0;
236	if (mask & LUA_MASKCALL) smask[i++] = 'c';
237	if (mask & LUA_MASKRET) smask[i++] = 'r';
238	if (mask & LUA_MASKLINE) smask[i++] = 'l';
239	smask[i] = '\0';
240	return smask;
241	}
242
243
244	static void gethooktable (lua_State *L) {
245	lua_pushlightuserdata(L, (void *)&KEY_HOOK);
246	lua_rawget(L, LUA_REGISTRYINDEX);
247	if (!lua_istable(L, -1)) {
248	lua_pop(L, 1);
249	lua_createtable(L, 0, 1);
250	lua_pushlightuserdata(L, (void *)&KEY_HOOK);
251	lua_pushvalue(L, -2);
252	lua_rawset(L, LUA_REGISTRYINDEX);
253	}
254	}
255
256
257	static int db_sethook (lua_State *L) {
258	int arg, mask, count;
259	lua_Hook func;
260	lua_State *L1 = getthread(L, &arg);
261	if (lua_isnoneornil(L, arg+1)) {
262	lua_settop(L, arg+1);
263	func = NULL; mask = 0; count = 0; /* turn off hooks */
264	}
265	else {
266	const char *smask = luaL_checkstring(L, arg+2);
267	luaL_checktype(L, arg+1, LUA_TFUNCTION);
268	count = luaL_optint(L, arg+3, 0);
269	func = hookf; mask = makemask(smask, count);
270	}
271	gethooktable(L);
272	lua_pushlightuserdata(L, L1);
273	lua_pushvalue(L, arg+1);
274	lua_rawset(L, -3); /* set new hook */
275	lua_pop(L, 1); /* remove hook table */
276	lua_sethook(L1, func, mask, count); /* set hooks */
277	return 0;
278	}
279
280
281	static int db_gethook (lua_State *L) {
282	int arg;
283	lua_State *L1 = getthread(L, &arg);
284	char buff[5];
285	int mask = lua_gethookmask(L1);
286	lua_Hook hook = lua_gethook(L1);
287	if (hook != NULL && hook != hookf) /* external hook? */
288	lua_pushliteral(L, "external hook");
289	else {
290	gethooktable(L);
291	lua_pushlightuserdata(L, L1);
292	lua_rawget(L, -2); /* get hook */
293	lua_remove(L, -2); /* remove hook table */
294	}
295	lua_pushstring(L, unmakemask(mask, buff));
296	lua_pushinteger(L, lua_gethookcount(L1));
297	return 3;
298	}
299
300
301	static int db_debug (lua_State *L) {
302	for (;;) {
303	char buffer[250];
304	fputs("lua_debug> ", stderr);
305	if (fgets(buffer, sizeof(buffer), stdin) == 0 \|\|
306	strcmp(buffer, "cont\n") == 0)
307	return 0;
308	if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") \|\|
309	lua_pcall(L, 0, 0, 0)) {
310	fputs(lua_tostring(L, -1), stderr);
311	fputs("\n", stderr);
312	}
313	lua_settop(L, 0); /* remove eventual returns */
314	}
315	}
316
317
318	#define LEVELS1 12 /* size of the first part of the stack */
319	#define LEVELS2 10 /* size of the second part of the stack */
320
321	static int db_errorfb (lua_State *L) {
322	int level;
323	int firstpart = 1; /* still before eventual `...' */
324	int arg;
325	lua_State *L1 = getthread(L, &arg);
326	lua_Debug ar;
327	if (lua_isnumber(L, arg+2)) {
328	level = (int)lua_tointeger(L, arg+2);
329	lua_pop(L, 1);
330	}
331	else
332	level = (L == L1) ? 1 : 0; /* level 0 may be this own function */
333	if (lua_gettop(L) == arg)
334	lua_pushliteral(L, "");
335	else if (!lua_isstring(L, arg+1)) return 1; /* message is not a string */
336	else lua_pushliteral(L, "\n");
337	lua_pushliteral(L, "stack traceback:");
338	while (lua_getstack(L1, level++, &ar)) {
339	if (level > LEVELS1 && firstpart) {
340	/* no more than `LEVELS2' more levels? */
341	if (!lua_getstack(L1, level+LEVELS2, &ar))
342	level--; /* keep going */
343	else {
344	lua_pushliteral(L, "\n\t..."); /* too many levels */
345	while (lua_getstack(L1, level+LEVELS2, &ar)) /* find last levels */
346	level++;
347	}
348	firstpart = 0;
349	continue;
350	}
351	lua_pushliteral(L, "\n\t");
352	lua_getinfo(L1, "Snl", &ar);
353	lua_pushfstring(L, "%s:", ar.short_src);
354	if (ar.currentline > 0)
355	lua_pushfstring(L, "%d:", ar.currentline);
356	if (ar.namewhat != '\0') / is there a name? */
357	lua_pushfstring(L, " in function " LUA_QS, ar.name);
358	else {
359	if (ar.what == 'm') / main? */
360	lua_pushfstring(L, " in main chunk");
361	else if (ar.what == 'C' \|\| ar.what == 't')
362	lua_pushliteral(L, " ?"); /* C function or tail call */
363	else
364	lua_pushfstring(L, " in function <%s:%d>",
365	ar.short_src, ar.linedefined);
366	}
367	lua_concat(L, lua_gettop(L) - arg);
368	}
369	lua_concat(L, lua_gettop(L) - arg);
370	return 1;
371	}
372
373
374	static const luaL_Reg dblib[] = {
375	{"debug", db_debug},
376	{"getfenv", db_getfenv},
377	{"gethook", db_gethook},
378	{"getinfo", db_getinfo},
379	{"getlocal", db_getlocal},
380	{"getregistry", db_getregistry},
381	{"getmetatable", db_getmetatable},
382	{"getupvalue", db_getupvalue},
383	{"setfenv", db_setfenv},
384	{"sethook", db_sethook},
385	{"setlocal", db_setlocal},
386	{"setmetatable", db_setmetatable},
387	{"setupvalue", db_setupvalue},
388	{"traceback", db_errorfb},
389	{NULL, NULL}
390	};
391
392
393	LUALIB_API int luaopen_debug (lua_State *L) {
394	luaL_register(L, LUA_DBLIBNAME, dblib);
395	return 1;
396	}
397