liblua/ldblib.c

   1 /*
   2 ** $Id: ldblib.c,v 1.132 2012/01/19 20:14:44 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 #define HOOKKEY         "_HKEY"
  22
  23
  24
  25 static int db_getregistry (lua_State *L) {
  26   lua_pushvalue(L, LUA_REGISTRYINDEX);
  27   return 1;
  28 }
  29
  30
  31 static int db_getmetatable (lua_State *L) {
  32   luaL_checkany(L, 1);
  33   if (!lua_getmetatable(L, 1)) {
  34     lua_pushnil(L);  /* no metatable */
  35   }
  36   return 1;
  37 }
  38
  39
  40 static int db_setmetatable (lua_State *L) {
  41   int t = lua_type(L, 2);
  42   luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
  43                     "nil or table expected");
  44   lua_settop(L, 2);
  45   lua_setmetatable(L, 1);
  46   return 1;  /* return 1st argument */
  47 }
  48
  49
  50 static int db_getuservalue (lua_State *L) {
  51   if (lua_type(L, 1) != LUA_TUSERDATA)
  52     lua_pushnil(L);
  53   else
  54     lua_getuservalue(L, 1);
  55   return 1;
  56 }
  57
  58
  59 static int db_setuservalue (lua_State *L) {
  60   if (lua_type(L, 1) == LUA_TLIGHTUSERDATA)
  61     luaL_argerror(L, 1, "full userdata expected, got light userdata");
  62   luaL_checktype(L, 1, LUA_TUSERDATA);
  63   if (!lua_isnoneornil(L, 2))
  64     luaL_checktype(L, 2, LUA_TTABLE);
  65   lua_settop(L, 2);
  66   lua_setuservalue(L, 1);
  67   return 1;
  68 }
  69
  70
  71 static void settabss (lua_State *L, const char *i, const char *v) {
  72   lua_pushstring(L, v);
  73   lua_setfield(L, -2, i);
  74 }
  75
  76
  77 static void settabsi (lua_State *L, const char *i, int v) {
  78   lua_pushinteger(L, v);
  79   lua_setfield(L, -2, i);
  80 }
  81
  82
  83 static void settabsb (lua_State *L, const char *i, int v) {
  84   lua_pushboolean(L, v);
  85   lua_setfield(L, -2, i);
  86 }
  87
  88
  89 static lua_State *getthread (lua_State *L, int *arg) {
  90   if (lua_isthread(L, 1)) {
  91     *arg = 1;
  92     return lua_tothread(L, 1);
  93   }
  94   else {
  95     *arg = 0;
  96     return L;
  97   }
  98 }
  99
 100
 101 static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) {
 102   if (L == L1) {
 103     lua_pushvalue(L, -2);
 104     lua_remove(L, -3);
 105   }
 106   else
 107     lua_xmove(L1, L, 1);
 108   lua_setfield(L, -2, fname);
 109 }
 110
 111
 112 static int db_getinfo (lua_State *L) {
 113   lua_Debug ar;
 114   int arg;
 115   lua_State *L1 = getthread(L, &arg);
 116   const char *options = luaL_optstring(L, arg+2, "flnStu");
 117   if (lua_isnumber(L, arg+1)) {
 118     if (!lua_getstack(L1, (int)lua_tointeger(L, arg+1), &ar)) {
 119       lua_pushnil(L);  /* level out of range */
 120       return 1;
 121     }
 122   }
 123   else if (lua_isfunction(L, arg+1)) {
 124     lua_pushfstring(L, ">%s", options);
 125     options = lua_tostring(L, -1);
 126     lua_pushvalue(L, arg+1);
 127     lua_xmove(L, L1, 1);
 128   }
 129   else
 130     return luaL_argerror(L, arg+1, "function or level expected");
 131   if (!lua_getinfo(L1, options, &ar))
 132     return luaL_argerror(L, arg+2, "invalid option");
 133   lua_createtable(L, 0, 2);
 134   if (strchr(options, 'S')) {
 135     settabss(L, "source", ar.source);
 136     settabss(L, "short_src", ar.short_src);
 137     settabsi(L, "linedefined", ar.linedefined);
 138     settabsi(L, "lastlinedefined", ar.lastlinedefined);
 139     settabss(L, "what", ar.what);
 140   }
 141   if (strchr(options, 'l'))
 142     settabsi(L, "currentline", ar.currentline);
 143   if (strchr(options, 'u')) {
 144     settabsi(L, "nups", ar.nups);
 145     settabsi(L, "nparams", ar.nparams);
 146     settabsb(L, "isvararg", ar.isvararg);
 147   }
 148   if (strchr(options, 'n')) {
 149     settabss(L, "name", ar.name);
 150     settabss(L, "namewhat", ar.namewhat);
 151   }
 152   if (strchr(options, 't'))
 153     settabsb(L, "istailcall", ar.istailcall);
 154   if (strchr(options, 'L'))
 155     treatstackoption(L, L1, "activelines");
 156   if (strchr(options, 'f'))
 157     treatstackoption(L, L1, "func");
 158   return 1;  /* return table */
 159 }
 160
 161
 162 static int db_getlocal (lua_State *L) {
 163   int arg;
 164   lua_State *L1 = getthread(L, &arg);
 165   lua_Debug ar;
 166   const char *name;
 167   int nvar = luaL_checkint(L, arg+2);  /* local-variable index */
 168   if (lua_isfunction(L, arg + 1)) {  /* function argument? */
 169     lua_pushvalue(L, arg + 1);  /* push function */
 170     lua_pushstring(L, lua_getlocal(L, NULL, nvar));  /* push local name */
 171     return 1;
 172   }
 173   else {  /* stack-level argument */
 174     if (!lua_getstack(L1, luaL_checkint(L, arg+1), &ar))  /* out of range? */
 175       return luaL_argerror(L, arg+1, "level out of range");
 176     name = lua_getlocal(L1, &ar, nvar);
 177     if (name) {
 178       lua_xmove(L1, L, 1);  /* push local value */
 179       lua_pushstring(L, name);  /* push name */
 180       lua_pushvalue(L, -2);  /* re-order */
 181       return 2;
 182     }
 183     else {
 184       lua_pushnil(L);  /* no name (nor value) */
 185       return 1;
 186     }
 187   }
 188 }
 189
 190
 191 static int db_setlocal (lua_State *L) {
 192   int arg;
 193   lua_State *L1 = getthread(L, &arg);
 194   lua_Debug ar;
 195   if (!lua_getstack(L1, luaL_checkint(L, arg+1), &ar))  /* out of range? */
 196     return luaL_argerror(L, arg+1, "level out of range");
 197   luaL_checkany(L, arg+3);
 198   lua_settop(L, arg+3);
 199   lua_xmove(L, L1, 1);
 200   lua_pushstring(L, lua_setlocal(L1, &ar, luaL_checkint(L, arg+2)));
 201   return 1;
 202 }
 203
 204
 205 static int auxupvalue (lua_State *L, int get) {
 206   const char *name;
 207   int n = luaL_checkint(L, 2);
 208   luaL_checktype(L, 1, LUA_TFUNCTION);
 209   name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
 210   if (name == NULL) return 0;
 211   lua_pushstring(L, name);
 212   lua_insert(L, -(get+1));
 213   return get + 1;
 214 }
 215
 216
 217 static int db_getupvalue (lua_State *L) {
 218   return auxupvalue(L, 1);
 219 }
 220
 221
 222 static int db_setupvalue (lua_State *L) {
 223   luaL_checkany(L, 3);
 224   return auxupvalue(L, 0);
 225 }
 226
 227
 228 static int checkupval (lua_State *L, int argf, int argnup) {
 229   lua_Debug ar;
 230   int nup = luaL_checkint(L, argnup);
 231   luaL_checktype(L, argf, LUA_TFUNCTION);
 232   lua_pushvalue(L, argf);
 233   lua_getinfo(L, ">u", &ar);
 234   luaL_argcheck(L, 1 <= nup && nup <= ar.nups, argnup, "invalid upvalue index");
 235   return nup;
 236 }
 237
 238
 239 static int db_upvalueid (lua_State *L) {
 240   int n = checkupval(L, 1, 2);
 241   lua_pushlightuserdata(L, lua_upvalueid(L, 1, n));
 242   return 1;
 243 }
 244
 245
 246 static int db_upvaluejoin (lua_State *L) {
 247   int n1 = checkupval(L, 1, 2);
 248   int n2 = checkupval(L, 3, 4);
 249   luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected");
 250   luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected");
 251   lua_upvaluejoin(L, 1, n1, 3, n2);
 252   return 0;
 253 }
 254
 255
 256 #define gethooktable(L) luaL_getsubtable(L, LUA_REGISTRYINDEX, HOOKKEY)
 257
 258
 259 static void hookf (lua_State *L, lua_Debug *ar) {
 260   static const char *const hooknames[] =
 261     {"call", "return", "line", "count", "tail call"};
 262   gethooktable(L);
 263   lua_pushthread(L);
 264   lua_rawget(L, -2);
 265   if (lua_isfunction(L, -1)) {
 266     lua_pushstring(L, hooknames[(int)ar->event]);
 267     if (ar->currentline >= 0)
 268       lua_pushinteger(L, ar->currentline);
 269     else lua_pushnil(L);
 270     lua_assert(lua_getinfo(L, "lS", ar));
 271     lua_call(L, 2, 0);
 272   }
 273 }
 274
 275
 276 static int makemask (const char *smask, int count) {
 277   int mask = 0;
 278   if (strchr(smask, 'c')) mask |= LUA_MASKCALL;
 279   if (strchr(smask, 'r')) mask |= LUA_MASKRET;
 280   if (strchr(smask, 'l')) mask |= LUA_MASKLINE;
 281   if (count > 0) mask |= LUA_MASKCOUNT;
 282   return mask;
 283 }
 284
 285
 286 static char *unmakemask (int mask, char *smask) {
 287   int i = 0;
 288   if (mask & LUA_MASKCALL) smask[i++] = 'c';
 289   if (mask & LUA_MASKRET) smask[i++] = 'r';
 290   if (mask & LUA_MASKLINE) smask[i++] = 'l';
 291   smask[i] = '\0';
 292   return smask;
 293 }
 294
 295
 296 static int db_sethook (lua_State *L) {
 297   int arg, mask, count;
 298   lua_Hook func;
 299   lua_State *L1 = getthread(L, &arg);
 300   if (lua_isnoneornil(L, arg+1)) {
 301     lua_settop(L, arg+1);
 302     func = NULL; mask = 0; count = 0;  /* turn off hooks */
 303   }
 304   else {
 305     const char *smask = luaL_checkstring(L, arg+2);
 306     luaL_checktype(L, arg+1, LUA_TFUNCTION);
 307     count = luaL_optint(L, arg+3, 0);
 308     func = hookf; mask = makemask(smask, count);
 309   }
 310   if (gethooktable(L) == 0) {  /* creating hook table? */
 311     lua_pushstring(L, "k");
 312     lua_setfield(L, -2, "__mode");  /** hooktable.__mode = "k" */
 313     lua_pushvalue(L, -1);
 314     lua_setmetatable(L, -2);  /* setmetatable(hooktable) = hooktable */
 315   }
 316   lua_pushthread(L1); lua_xmove(L1, L, 1);
 317   lua_pushvalue(L, arg+1);
 318   lua_rawset(L, -3);  /* set new hook */
 319   lua_sethook(L1, func, mask, count);  /* set hooks */
 320   return 0;
 321 }
 322
 323
 324 static int db_gethook (lua_State *L) {
 325   int arg;
 326   lua_State *L1 = getthread(L, &arg);
 327   char buff[5];
 328   int mask = lua_gethookmask(L1);
 329   lua_Hook hook = lua_gethook(L1);
 330   if (hook != NULL && hook != hookf)  /* external hook? */
 331     lua_pushliteral(L, "external hook");
 332   else {
 333     gethooktable(L);
 334     lua_pushthread(L1); lua_xmove(L1, L, 1);
 335     lua_rawget(L, -2);   /* get hook */
 336     lua_remove(L, -2);  /* remove hook table */
 337   }
 338   lua_pushstring(L, unmakemask(mask, buff));
 339   lua_pushinteger(L, lua_gethookcount(L1));
 340   return 3;
 341 }
 342
 343
 344 static int db_debug (lua_State *L) {
 345   for (;;) {
 346     char buffer[250];
 347     luai_writestringerror("%s", "lua_debug> ");
 348     if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
 349         strcmp(buffer, "cont\n") == 0)
 350       return 0;
 351     if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
 352         lua_pcall(L, 0, 0, 0))
 353       luai_writestringerror("%s\n", lua_tostring(L, -1));
 354     lua_settop(L, 0);  /* remove eventual returns */
 355   }
 356 }
 357
 358
 359 static int db_traceback (lua_State *L) {
 360   int arg;
 361   lua_State *L1 = getthread(L, &arg);
 362   const char *msg = lua_tostring(L, arg + 1);
 363   if (msg == NULL && !lua_isnoneornil(L, arg + 1))  /* non-string 'msg'? */
 364     lua_pushvalue(L, arg + 1);  /* return it untouched */
 365   else {
 366     int level = luaL_optint(L, arg + 2, (L == L1) ? 1 : 0);
 367     luaL_traceback(L, L1, msg, level);
 368   }
 369   return 1;
 370 }
 371
 372
 373 static const luaL_Reg dblib[] = {
 374   {"debug", db_debug},
 375   {"getuservalue", db_getuservalue},
 376   {"gethook", db_gethook},
 377   {"getinfo", db_getinfo},
 378   {"getlocal", db_getlocal},
 379   {"getregistry", db_getregistry},
 380   {"getmetatable", db_getmetatable},
 381   {"getupvalue", db_getupvalue},
 382   {"upvaluejoin", db_upvaluejoin},
 383   {"upvalueid", db_upvalueid},
 384   {"setuservalue", db_setuservalue},
 385   {"sethook", db_sethook},
 386   {"setlocal", db_setlocal},
 387   {"setmetatable", db_setmetatable},
 388   {"setupvalue", db_setupvalue},
 389   {"traceback", db_traceback},
 390   {NULL, NULL}
 391 };
 392
 393
 394 LUAMOD_API int luaopen_debug (lua_State *L) {
 395   luaL_newlib(L, dblib);
 396   return 1;
 397 }
 398