1 /* 2 ** $Id: ldblib.c,v 1.151.1.1 2017/04/19 17:20:42 roberto Exp $ 3 ** Interface from Lua to its debug API 4 ** See Copyright Notice in lua.h 5 */ 6 7 #define ldblib_c 8 #define LUA_LIB 9 10 #include "lprefix.h" 11 12 13 #include <stdio.h> 14 #include <stdlib.h> 15 #include <string.h> 16 17 #include "lua.h" 18 19 #include "lauxlib.h" 20 #include "lualib.h" 21 22 23 /* 24 ** The hook table at registry[&HOOKKEY] maps threads to their current 25 ** hook function. (We only need the unique address of 'HOOKKEY'.) 26 */ 27 static const int HOOKKEY = 0; 28 29 30 /* 31 ** If L1 != L, L1 can be in any state, and therefore there are no 32 ** guarantees about its stack space; any push in L1 must be 33 ** checked. 34 */ 35 static void checkstack (lua_State *L, lua_State *L1, int n) { 36 if (L != L1 && !lua_checkstack(L1, n)) 37 luaL_error(L, "stack overflow"); 38 } 39 40 41 static int db_getregistry (lua_State *L) { 42 lua_pushvalue(L, LUA_REGISTRYINDEX); 43 return 1; 44 } 45 46 47 static int db_getmetatable (lua_State *L) { 48 luaL_checkany(L, 1); 49 if (!lua_getmetatable(L, 1)) { 50 lua_pushnil(L); /* no metatable */ 51 } 52 return 1; 53 } 54 55 56 static int db_setmetatable (lua_State *L) { 57 int t = lua_type(L, 2); 58 luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2, 59 "nil or table expected"); 60 lua_settop(L, 2); 61 lua_setmetatable(L, 1); 62 return 1; /* return 1st argument */ 63 } 64 65 66 static int db_getuservalue (lua_State *L) { 67 if (lua_type(L, 1) != LUA_TUSERDATA) 68 lua_pushnil(L); 69 else 70 lua_getuservalue(L, 1); 71 return 1; 72 } 73 74 75 static int db_setuservalue (lua_State *L) { 76 luaL_checktype(L, 1, LUA_TUSERDATA); 77 luaL_checkany(L, 2); 78 lua_settop(L, 2); 79 lua_setuservalue(L, 1); 80 return 1; 81 } 82 83 84 /* 85 ** Auxiliary function used by several library functions: check for 86 ** an optional thread as function's first argument and set 'arg' with 87 ** 1 if this argument is present (so that functions can skip it to 88 ** access their other arguments) 89 */ 90 static lua_State *getthread (lua_State *L, int *arg) { 91 if (lua_isthread(L, 1)) { 92 *arg = 1; 93 return lua_tothread(L, 1); 94 } 95 else { 96 *arg = 0; 97 return L; /* function will operate over current thread */ 98 } 99 } 100 101 102 /* 103 ** Variations of 'lua_settable', used by 'db_getinfo' to put results 104 ** from 'lua_getinfo' into result table. Key is always a string; 105 ** value can be a string, an int, or a boolean. 106 */ 107 static void settabss (lua_State *L, const char *k, const char *v) { 108 lua_pushstring(L, v); 109 lua_setfield(L, -2, k); 110 } 111 112 static void settabsi (lua_State *L, const char *k, int v) { 113 lua_pushinteger(L, v); 114 lua_setfield(L, -2, k); 115 } 116 117 static void settabsb (lua_State *L, const char *k, int v) { 118 lua_pushboolean(L, v); 119 lua_setfield(L, -2, k); 120 } 121 122 123 /* 124 ** In function 'db_getinfo', the call to 'lua_getinfo' may push 125 ** results on the stack; later it creates the result table to put 126 ** these objects. Function 'treatstackoption' puts the result from 127 ** 'lua_getinfo' on top of the result table so that it can call 128 ** 'lua_setfield'. 129 */ 130 static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) { 131 if (L == L1) 132 lua_rotate(L, -2, 1); /* exchange object and table */ 133 else 134 lua_xmove(L1, L, 1); /* move object to the "main" stack */ 135 lua_setfield(L, -2, fname); /* put object into table */ 136 } 137 138 139 /* 140 ** Calls 'lua_getinfo' and collects all results in a new table. 141 ** L1 needs stack space for an optional input (function) plus 142 ** two optional outputs (function and line table) from function 143 ** 'lua_getinfo'. 144 */ 145 static int db_getinfo (lua_State *L) { 146 lua_Debug ar; 147 int arg; 148 lua_State *L1 = getthread(L, &arg); 149 const char *options = luaL_optstring(L, arg+2, "flnStu"); 150 checkstack(L, L1, 3); 151 if (lua_isfunction(L, arg + 1)) { /* info about a function? */ 152 options = lua_pushfstring(L, ">%s", options); /* add '>' to 'options' */ 153 lua_pushvalue(L, arg + 1); /* move function to 'L1' stack */ 154 lua_xmove(L, L1, 1); 155 } 156 else { /* stack level */ 157 if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) { 158 lua_pushnil(L); /* level out of range */ 159 return 1; 160 } 161 } 162 if (!lua_getinfo(L1, options, &ar)) 163 return luaL_argerror(L, arg+2, "invalid option"); 164 lua_newtable(L); /* table to collect results */ 165 if (strchr(options, 'S')) { 166 settabss(L, "source", ar.source); 167 settabss(L, "short_src", ar.short_src); 168 settabsi(L, "linedefined", ar.linedefined); 169 settabsi(L, "lastlinedefined", ar.lastlinedefined); 170 settabss(L, "what", ar.what); 171 } 172 if (strchr(options, 'l')) 173 settabsi(L, "currentline", ar.currentline); 174 if (strchr(options, 'u')) { 175 settabsi(L, "nups", ar.nups); 176 settabsi(L, "nparams", ar.nparams); 177 settabsb(L, "isvararg", ar.isvararg); 178 } 179 if (strchr(options, 'n')) { 180 settabss(L, "name", ar.name); 181 settabss(L, "namewhat", ar.namewhat); 182 } 183 if (strchr(options, 't')) 184 settabsb(L, "istailcall", ar.istailcall); 185 if (strchr(options, 'L')) 186 treatstackoption(L, L1, "activelines"); 187 if (strchr(options, 'f')) 188 treatstackoption(L, L1, "func"); 189 return 1; /* return table */ 190 } 191 192 193 static int db_getlocal (lua_State *L) { 194 int arg; 195 lua_State *L1 = getthread(L, &arg); 196 lua_Debug ar; 197 const char *name; 198 int nvar = (int)luaL_checkinteger(L, arg + 2); /* local-variable index */ 199 if (lua_isfunction(L, arg + 1)) { /* function argument? */ 200 lua_pushvalue(L, arg + 1); /* push function */ 201 lua_pushstring(L, lua_getlocal(L, NULL, nvar)); /* push local name */ 202 return 1; /* return only name (there is no value) */ 203 } 204 else { /* stack-level argument */ 205 int level = (int)luaL_checkinteger(L, arg + 1); 206 if (!lua_getstack(L1, level, &ar)) /* out of range? */ 207 return luaL_argerror(L, arg+1, "level out of range"); 208 checkstack(L, L1, 1); 209 name = lua_getlocal(L1, &ar, nvar); 210 if (name) { 211 lua_xmove(L1, L, 1); /* move local value */ 212 lua_pushstring(L, name); /* push name */ 213 lua_rotate(L, -2, 1); /* re-order */ 214 return 2; 215 } 216 else { 217 lua_pushnil(L); /* no name (nor value) */ 218 return 1; 219 } 220 } 221 } 222 223 224 static int db_setlocal (lua_State *L) { 225 int arg; 226 const char *name; 227 lua_State *L1 = getthread(L, &arg); 228 lua_Debug ar; 229 int level = (int)luaL_checkinteger(L, arg + 1); 230 int nvar = (int)luaL_checkinteger(L, arg + 2); 231 if (!lua_getstack(L1, level, &ar)) /* out of range? */ 232 return luaL_argerror(L, arg+1, "level out of range"); 233 luaL_checkany(L, arg+3); 234 lua_settop(L, arg+3); 235 checkstack(L, L1, 1); 236 lua_xmove(L, L1, 1); 237 name = lua_setlocal(L1, &ar, nvar); 238 if (name == NULL) 239 lua_pop(L1, 1); /* pop value (if not popped by 'lua_setlocal') */ 240 lua_pushstring(L, name); 241 return 1; 242 } 243 244 245 /* 246 ** get (if 'get' is true) or set an upvalue from a closure 247 */ 248 static int auxupvalue (lua_State *L, int get) { 249 const char *name; 250 int n = (int)luaL_checkinteger(L, 2); /* upvalue index */ 251 luaL_checktype(L, 1, LUA_TFUNCTION); /* closure */ 252 name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n); 253 if (name == NULL) return 0; 254 lua_pushstring(L, name); 255 lua_insert(L, -(get+1)); /* no-op if get is false */ 256 return get + 1; 257 } 258 259 260 static int db_getupvalue (lua_State *L) { 261 return auxupvalue(L, 1); 262 } 263 264 265 static int db_setupvalue (lua_State *L) { 266 luaL_checkany(L, 3); 267 return auxupvalue(L, 0); 268 } 269 270 271 /* 272 ** Check whether a given upvalue from a given closure exists and 273 ** returns its index 274 */ 275 static int checkupval (lua_State *L, int argf, int argnup) { 276 int nup = (int)luaL_checkinteger(L, argnup); /* upvalue index */ 277 luaL_checktype(L, argf, LUA_TFUNCTION); /* closure */ 278 luaL_argcheck(L, (lua_getupvalue(L, argf, nup) != NULL), argnup, 279 "invalid upvalue index"); 280 return nup; 281 } 282 283 284 static int db_upvalueid (lua_State *L) { 285 int n = checkupval(L, 1, 2); 286 lua_pushlightuserdata(L, lua_upvalueid(L, 1, n)); 287 return 1; 288 } 289 290 291 static int db_upvaluejoin (lua_State *L) { 292 int n1 = checkupval(L, 1, 2); 293 int n2 = checkupval(L, 3, 4); 294 luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected"); 295 luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected"); 296 lua_upvaluejoin(L, 1, n1, 3, n2); 297 return 0; 298 } 299 300 301 /* 302 ** Call hook function registered at hook table for the current 303 ** thread (if there is one) 304 */ 305 static void hookf (lua_State *L, lua_Debug *ar) { 306 static const char *const hooknames[] = 307 {"call", "return", "line", "count", "tail call"}; 308 lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY); 309 lua_pushthread(L); 310 if (lua_rawget(L, -2) == LUA_TFUNCTION) { /* is there a hook function? */ 311 lua_pushstring(L, hooknames[(int)ar->event]); /* push event name */ 312 if (ar->currentline >= 0) 313 lua_pushinteger(L, ar->currentline); /* push current line */ 314 else lua_pushnil(L); 315 lua_assert(lua_getinfo(L, "lS", ar)); 316 lua_call(L, 2, 0); /* call hook function */ 317 } 318 } 319 320 321 /* 322 ** Convert a string mask (for 'sethook') into a bit mask 323 */ 324 static int makemask (const char *smask, int count) { 325 int mask = 0; 326 if (strchr(smask, 'c')) mask |= LUA_MASKCALL; 327 if (strchr(smask, 'r')) mask |= LUA_MASKRET; 328 if (strchr(smask, 'l')) mask |= LUA_MASKLINE; 329 if (count > 0) mask |= LUA_MASKCOUNT; 330 return mask; 331 } 332 333 334 /* 335 ** Convert a bit mask (for 'gethook') into a string mask 336 */ 337 static char *unmakemask (int mask, char *smask) { 338 int i = 0; 339 if (mask & LUA_MASKCALL) smask[i++] = 'c'; 340 if (mask & LUA_MASKRET) smask[i++] = 'r'; 341 if (mask & LUA_MASKLINE) smask[i++] = 'l'; 342 smask[i] = '\0'; 343 return smask; 344 } 345 346 347 static int db_sethook (lua_State *L) { 348 int arg, mask, count; 349 lua_Hook func; 350 lua_State *L1 = getthread(L, &arg); 351 if (lua_isnoneornil(L, arg+1)) { /* no hook? */ 352 lua_settop(L, arg+1); 353 func = NULL; mask = 0; count = 0; /* turn off hooks */ 354 } 355 else { 356 const char *smask = luaL_checkstring(L, arg+2); 357 luaL_checktype(L, arg+1, LUA_TFUNCTION); 358 count = (int)luaL_optinteger(L, arg + 3, 0); 359 func = hookf; mask = makemask(smask, count); 360 } 361 if (lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY) == LUA_TNIL) { 362 lua_createtable(L, 0, 2); /* create a hook table */ 363 lua_pushvalue(L, -1); 364 lua_rawsetp(L, LUA_REGISTRYINDEX, &HOOKKEY); /* set it in position */ 365 lua_pushstring(L, "k"); 366 lua_setfield(L, -2, "__mode"); /** hooktable.__mode = "k" */ 367 lua_pushvalue(L, -1); 368 lua_setmetatable(L, -2); /* setmetatable(hooktable) = hooktable */ 369 } 370 checkstack(L, L1, 1); 371 lua_pushthread(L1); lua_xmove(L1, L, 1); /* key (thread) */ 372 lua_pushvalue(L, arg + 1); /* value (hook function) */ 373 lua_rawset(L, -3); /* hooktable[L1] = new Lua hook */ 374 lua_sethook(L1, func, mask, count); 375 return 0; 376 } 377 378 379 static int db_gethook (lua_State *L) { 380 int arg; 381 lua_State *L1 = getthread(L, &arg); 382 char buff[5]; 383 int mask = lua_gethookmask(L1); 384 lua_Hook hook = lua_gethook(L1); 385 if (hook == NULL) /* no hook? */ 386 lua_pushnil(L); 387 else if (hook != hookf) /* external hook? */ 388 lua_pushliteral(L, "external hook"); 389 else { /* hook table must exist */ 390 lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY); 391 checkstack(L, L1, 1); 392 lua_pushthread(L1); lua_xmove(L1, L, 1); 393 lua_rawget(L, -2); /* 1st result = hooktable[L1] */ 394 lua_remove(L, -2); /* remove hook table */ 395 } 396 lua_pushstring(L, unmakemask(mask, buff)); /* 2nd result = mask */ 397 lua_pushinteger(L, lua_gethookcount(L1)); /* 3rd result = count */ 398 return 3; 399 } 400 401 402 static int db_debug (lua_State *L) { 403 for (;;) { 404 char buffer[250]; 405 lua_writestringerror("%s", "lua_debug> "); 406 if (fgets(buffer, sizeof(buffer), stdin) == 0 || 407 strcmp(buffer, "cont\n") == 0) 408 return 0; 409 if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") || 410 lua_pcall(L, 0, 0, 0)) 411 lua_writestringerror("%s\n", lua_tostring(L, -1)); 412 lua_settop(L, 0); /* remove eventual returns */ 413 } 414 } 415 416 417 static int db_traceback (lua_State *L) { 418 int arg; 419 lua_State *L1 = getthread(L, &arg); 420 const char *msg = lua_tostring(L, arg + 1); 421 if (msg == NULL && !lua_isnoneornil(L, arg + 1)) /* non-string 'msg'? */ 422 lua_pushvalue(L, arg + 1); /* return it untouched */ 423 else { 424 int level = (int)luaL_optinteger(L, arg + 2, (L == L1) ? 1 : 0); 425 luaL_traceback(L, L1, msg, level); 426 } 427 return 1; 428 } 429 430 431 static const luaL_Reg dblib[] = { 432 {"debug", db_debug}, 433 {"getuservalue", db_getuservalue}, 434 {"gethook", db_gethook}, 435 {"getinfo", db_getinfo}, 436 {"getlocal", db_getlocal}, 437 {"getregistry", db_getregistry}, 438 {"getmetatable", db_getmetatable}, 439 {"getupvalue", db_getupvalue}, 440 {"upvaluejoin", db_upvaluejoin}, 441 {"upvalueid", db_upvalueid}, 442 {"setuservalue", db_setuservalue}, 443 {"sethook", db_sethook}, 444 {"setlocal", db_setlocal}, 445 {"setmetatable", db_setmetatable}, 446 {"setupvalue", db_setupvalue}, 447 {"traceback", db_traceback}, 448 {NULL, NULL} 449 }; 450 451 452 LUAMOD_API int luaopen_debug (lua_State *L) { 453 luaL_newlib(L, dblib); 454 return 1; 455 } 456 457
