src/ldblib.c

   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