1 /* $NetBSD: ldblib.c,v 1.5 2015/02/02 14:03:05 lneto Exp $ */ 2 3 /* 4 ** Id: ldblib.c,v 1.148 2015/01/02 12:52:22 roberto Exp 5 ** Interface from Lua to its debug API 6 ** See Copyright Notice in lua.h 7 */ 8 9 #define ldblib_c 10 #define LUA_LIB 11 12 #include "lprefix.h" 13 14 15 #ifndef _KERNEL 16 #include <stdio.h> 17 #include <stdlib.h> 18 #include <string.h> 19 #endif 20 21 #include "lua.h" 22 23 #include "lauxlib.h" 24 #include "lualib.h" 25 26 27 /* 28 ** The hook table at registry[&HOOKKEY] maps threads to their current 29 ** hook function. (We only need the unique address of 'HOOKKEY'.) 30 */ 31 static const int HOOKKEY = 0; 32 33 34 static int db_getregistry (lua_State *L) { 35 lua_pushvalue(L, LUA_REGISTRYINDEX); 36 return 1; 37 } 38 39 40 static int db_getmetatable (lua_State *L) { 41 luaL_checkany(L, 1); 42 if (!lua_getmetatable(L, 1)) { 43 lua_pushnil(L); /* no metatable */ 44 } 45 return 1; 46 } 47 48 49 static int db_setmetatable (lua_State *L) { 50 int t = lua_type(L, 2); 51 luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2, 52 "nil or table expected"); 53 lua_settop(L, 2); 54 lua_setmetatable(L, 1); 55 return 1; /* return 1st argument */ 56 } 57 58 59 static int db_getuservalue (lua_State *L) { 60 if (lua_type(L, 1) != LUA_TUSERDATA) 61 lua_pushnil(L); 62 else 63 lua_getuservalue(L, 1); 64 return 1; 65 } 66 67 68 static int db_setuservalue (lua_State *L) { 69 luaL_checktype(L, 1, LUA_TUSERDATA); 70 luaL_checkany(L, 2); 71 lua_settop(L, 2); 72 lua_setuservalue(L, 1); 73 return 1; 74 } 75 76 77 /* 78 ** Auxiliary function used by several library functions: check for 79 ** an optional thread as function's first argument and set 'arg' with 80 ** 1 if this argument is present (so that functions can skip it to 81 ** access their other arguments) 82 */ 83 static lua_State *getthread (lua_State *L, int *arg) { 84 if (lua_isthread(L, 1)) { 85 *arg = 1; 86 return lua_tothread(L, 1); 87 } 88 else { 89 *arg = 0; 90 return L; /* function will operate over current thread */ 91 } 92 } 93 94 95 /* 96 ** Variations of 'lua_settable', used by 'db_getinfo' to put results 97 ** from 'lua_getinfo' into result table. Key is always a string; 98 ** value can be a string, an int, or a boolean. 99 */ 100 static void settabss (lua_State *L, const char *k, const char *v) { 101 lua_pushstring(L, v); 102 lua_setfield(L, -2, k); 103 } 104 105 static void settabsi (lua_State *L, const char *k, int v) { 106 lua_pushinteger(L, v); 107 lua_setfield(L, -2, k); 108 } 109 110 static void settabsb (lua_State *L, const char *k, int v) { 111 lua_pushboolean(L, v); 112 lua_setfield(L, -2, k); 113 } 114 115 116 /* 117 ** In function 'db_getinfo', the call to 'lua_getinfo' may push 118 ** results on the stack; later it creates the result table to put 119 ** these objects. Function 'treatstackoption' puts the result from 120 ** 'lua_getinfo' on top of the result table so that it can call 121 ** 'lua_setfield'. 122 */ 123 static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) { 124 if (L == L1) 125 lua_rotate(L, -2, 1); /* exchange object and table */ 126 else 127 lua_xmove(L1, L, 1); /* move object to the "main" stack */ 128 lua_setfield(L, -2, fname); /* put object into table */ 129 } 130 131 132 /* 133 ** Calls 'lua_getinfo' and collects all results in a new table. 134 */ 135 static int db_getinfo (lua_State *L) { 136 lua_Debug ar; 137 int arg; 138 lua_State *L1 = getthread(L, &arg); 139 const char *options = luaL_optstring(L, arg+2, "flnStu"); 140 if (lua_isfunction(L, arg + 1)) { /* info about a function? */ 141 options = lua_pushfstring(L, ">%s", options); /* add '>' to 'options' */ 142 lua_pushvalue(L, arg + 1); /* move function to 'L1' stack */ 143 lua_xmove(L, L1, 1); 144 } 145 else { /* stack level */ 146 if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) { 147 lua_pushnil(L); /* level out of range */ 148 return 1; 149 } 150 } 151 if (!lua_getinfo(L1, options, &ar)) 152 return luaL_argerror(L, arg+2, "invalid option"); 153 lua_newtable(L); /* table to collect results */ 154 if (strchr(options, 'S')) { 155 settabss(L, "source", ar.source); 156 settabss(L, "short_src", ar.short_src); 157 settabsi(L, "linedefined", ar.linedefined); 158 settabsi(L, "lastlinedefined", ar.lastlinedefined); 159 settabss(L, "what", ar.what); 160 } 161 if (strchr(options, 'l')) 162 settabsi(L, "currentline", ar.currentline); 163 if (strchr(options, 'u')) { 164 settabsi(L, "nups", ar.nups); 165 settabsi(L, "nparams", ar.nparams); 166 settabsb(L, "isvararg", ar.isvararg); 167 } 168 if (strchr(options, 'n')) { 169 settabss(L, "name", ar.name); 170 settabss(L, "namewhat", ar.namewhat); 171 } 172 if (strchr(options, 't')) 173 settabsb(L, "istailcall", ar.istailcall); 174 if (strchr(options, 'L')) 175 treatstackoption(L, L1, "activelines"); 176 if (strchr(options, 'f')) 177 treatstackoption(L, L1, "func"); 178 return 1; /* return table */ 179 } 180 181 182 static int db_getlocal (lua_State *L) { 183 int arg; 184 lua_State *L1 = getthread(L, &arg); 185 lua_Debug ar; 186 const char *name; 187 int nvar = (int)luaL_checkinteger(L, arg + 2); /* local-variable index */ 188 if (lua_isfunction(L, arg + 1)) { /* function argument? */ 189 lua_pushvalue(L, arg + 1); /* push function */ 190 lua_pushstring(L, lua_getlocal(L, NULL, nvar)); /* push local name */ 191 return 1; /* return only name (there is no value) */ 192 } 193 else { /* stack-level argument */ 194 int level = (int)luaL_checkinteger(L, arg + 1); 195 if (!lua_getstack(L1, level, &ar)) /* out of range? */ 196 return luaL_argerror(L, arg+1, "level out of range"); 197 name = lua_getlocal(L1, &ar, nvar); 198 if (name) { 199 lua_xmove(L1, L, 1); /* move local value */ 200 lua_pushstring(L, name); /* push name */ 201 lua_rotate(L, -2, 1); /* re-order */ 202 return 2; 203 } 204 else { 205 lua_pushnil(L); /* no name (nor value) */ 206 return 1; 207 } 208 } 209 } 210 211 212 static int db_setlocal (lua_State *L) { 213 int arg; 214 const char *name; 215 lua_State *L1 = getthread(L, &arg); 216 lua_Debug ar; 217 int level = (int)luaL_checkinteger(L, arg + 1); 218 int nvar = (int)luaL_checkinteger(L, arg + 2); 219 if (!lua_getstack(L1, level, &ar)) /* out of range? */ 220 return luaL_argerror(L, arg+1, "level out of range"); 221 luaL_checkany(L, arg+3); 222 lua_settop(L, arg+3); 223 lua_xmove(L, L1, 1); 224 name = lua_setlocal(L1, &ar, nvar); 225 if (name == NULL) 226 lua_pop(L1, 1); /* pop value (if not popped by 'lua_setlocal') */ 227 lua_pushstring(L, name); 228 return 1; 229 } 230 231 232 /* 233 ** get (if 'get' is true) or set an upvalue from a closure 234 */ 235 static int auxupvalue (lua_State *L, int get) { 236 const char *name; 237 int n = (int)luaL_checkinteger(L, 2); /* upvalue index */ 238 luaL_checktype(L, 1, LUA_TFUNCTION); /* closure */ 239 name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n); 240 if (name == NULL) return 0; 241 lua_pushstring(L, name); 242 lua_insert(L, -(get+1)); /* no-op if get is false */ 243 return get + 1; 244 } 245 246 247 static int db_getupvalue (lua_State *L) { 248 return auxupvalue(L, 1); 249 } 250 251 252 static int db_setupvalue (lua_State *L) { 253 luaL_checkany(L, 3); 254 return auxupvalue(L, 0); 255 } 256 257 258 /* 259 ** Check whether a given upvalue from a given closure exists and 260 ** returns its index 261 */ 262 static int checkupval (lua_State *L, int argf, int argnup) { 263 int nup = (int)luaL_checkinteger(L, argnup); /* upvalue index */ 264 luaL_checktype(L, argf, LUA_TFUNCTION); /* closure */ 265 luaL_argcheck(L, (lua_getupvalue(L, argf, nup) != NULL), argnup, 266 "invalid upvalue index"); 267 return nup; 268 } 269 270 271 static int db_upvalueid (lua_State *L) { 272 int n = checkupval(L, 1, 2); 273 lua_pushlightuserdata(L, lua_upvalueid(L, 1, n)); 274 return 1; 275 } 276 277 278 static int db_upvaluejoin (lua_State *L) { 279 int n1 = checkupval(L, 1, 2); 280 int n2 = checkupval(L, 3, 4); 281 luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected"); 282 luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected"); 283 lua_upvaluejoin(L, 1, n1, 3, n2); 284 return 0; 285 } 286 287 288 /* 289 ** Call hook function registered at hook table for the current 290 ** thread (if there is one) 291 */ 292 static void hookf (lua_State *L, lua_Debug *ar) { 293 static const char *const hooknames[] = 294 {"call", "return", "line", "count", "tail call"}; 295 lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY); 296 lua_pushthread(L); 297 if (lua_rawget(L, -2) == LUA_TFUNCTION) { /* is there a hook function? */ 298 lua_pushstring(L, hooknames[(int)ar->event]); /* push event name */ 299 if (ar->currentline >= 0) 300 lua_pushinteger(L, ar->currentline); /* push current line */ 301 else lua_pushnil(L); 302 lua_assert(lua_getinfo(L, "lS", ar)); 303 lua_call(L, 2, 0); /* call hook function */ 304 } 305 } 306 307 308 /* 309 ** Convert a string mask (for 'sethook') into a bit mask 310 */ 311 static int makemask (const char *smask, int count) { 312 int mask = 0; 313 if (strchr(smask, 'c')) mask |= LUA_MASKCALL; 314 if (strchr(smask, 'r')) mask |= LUA_MASKRET; 315 if (strchr(smask, 'l')) mask |= LUA_MASKLINE; 316 if (count > 0) mask |= LUA_MASKCOUNT; 317 return mask; 318 } 319 320 321 /* 322 ** Convert a bit mask (for 'gethook') into a string mask 323 */ 324 static char *unmakemask (int mask, char *smask) { 325 int i = 0; 326 if (mask & LUA_MASKCALL) smask[i++] = 'c'; 327 if (mask & LUA_MASKRET) smask[i++] = 'r'; 328 if (mask & LUA_MASKLINE) smask[i++] = 'l'; 329 smask[i] = '\0'; 330 return smask; 331 } 332 333 334 static int db_sethook (lua_State *L) { 335 int arg, mask, count; 336 lua_Hook func; 337 lua_State *L1 = getthread(L, &arg); 338 if (lua_isnoneornil(L, arg+1)) { /* no hook? */ 339 lua_settop(L, arg+1); 340 func = NULL; mask = 0; count = 0; /* turn off hooks */ 341 } 342 else { 343 const char *smask = luaL_checkstring(L, arg+2); 344 luaL_checktype(L, arg+1, LUA_TFUNCTION); 345 count = (int)luaL_optinteger(L, arg + 3, 0); 346 func = hookf; mask = makemask(smask, count); 347 } 348 if (lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY) == LUA_TNIL) { 349 lua_createtable(L, 0, 2); /* create a hook table */ 350 lua_pushvalue(L, -1); 351 lua_rawsetp(L, LUA_REGISTRYINDEX, &HOOKKEY); /* set it in position */ 352 lua_pushstring(L, "k"); 353 lua_setfield(L, -2, "__mode"); /** hooktable.__mode = "k" */ 354 lua_pushvalue(L, -1); 355 lua_setmetatable(L, -2); /* setmetatable(hooktable) = hooktable */ 356 } 357 lua_pushthread(L1); lua_xmove(L1, L, 1); /* key (thread) */ 358 lua_pushvalue(L, arg + 1); /* value (hook function) */ 359 lua_rawset(L, -3); /* hooktable[L1] = new Lua hook */ 360 lua_sethook(L1, func, mask, count); 361 return 0; 362 } 363 364 365 static int db_gethook (lua_State *L) { 366 int arg; 367 lua_State *L1 = getthread(L, &arg); 368 char buff[5]; 369 int mask = lua_gethookmask(L1); 370 lua_Hook hook = lua_gethook(L1); 371 if (hook == NULL) /* no hook? */ 372 lua_pushnil(L); 373 else if (hook != hookf) /* external hook? */ 374 lua_pushliteral(L, "external hook"); 375 else { /* hook table must exist */ 376 lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY); 377 lua_pushthread(L1); lua_xmove(L1, L, 1); 378 lua_rawget(L, -2); /* 1st result = hooktable[L1] */ 379 lua_remove(L, -2); /* remove hook table */ 380 } 381 lua_pushstring(L, unmakemask(mask, buff)); /* 2nd result = mask */ 382 lua_pushinteger(L, lua_gethookcount(L1)); /* 3rd result = count */ 383 return 3; 384 } 385 386 387 #ifndef _KERNEL 388 static int db_debug (lua_State *L) { 389 for (;;) { 390 char buffer[250]; 391 lua_writestringerror("%s", "lua_debug> "); 392 if (fgets(buffer, sizeof(buffer), stdin) == 0 || 393 strcmp(buffer, "cont\n") == 0) 394 return 0; 395 if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") || 396 lua_pcall(L, 0, 0, 0)) 397 lua_writestringerror("%s\n", lua_tostring(L, -1)); 398 lua_settop(L, 0); /* remove eventual returns */ 399 } 400 } 401 #endif 402 403 404 static int db_traceback (lua_State *L) { 405 int arg; 406 lua_State *L1 = getthread(L, &arg); 407 const char *msg = lua_tostring(L, arg + 1); 408 if (msg == NULL && !lua_isnoneornil(L, arg + 1)) /* non-string 'msg'? */ 409 lua_pushvalue(L, arg + 1); /* return it untouched */ 410 else { 411 int level = (int)luaL_optinteger(L, arg + 2, (L == L1) ? 1 : 0); 412 luaL_traceback(L, L1, msg, level); 413 } 414 return 1; 415 } 416 417 418 static const luaL_Reg dblib[] = { 419 #ifndef _KERNEL 420 {"debug", db_debug}, 421 #endif 422 {"getuservalue", db_getuservalue}, 423 {"gethook", db_gethook}, 424 {"getinfo", db_getinfo}, 425 {"getlocal", db_getlocal}, 426 {"getregistry", db_getregistry}, 427 {"getmetatable", db_getmetatable}, 428 {"getupvalue", db_getupvalue}, 429 {"upvaluejoin", db_upvaluejoin}, 430 {"upvalueid", db_upvalueid}, 431 {"setuservalue", db_setuservalue}, 432 {"sethook", db_sethook}, 433 {"setlocal", db_setlocal}, 434 {"setmetatable", db_setmetatable}, 435 {"setupvalue", db_setupvalue}, 436 {"traceback", db_traceback}, 437 {NULL, NULL} 438 }; 439 440 441 LUAMOD_API int luaopen_debug (lua_State *L) { 442 luaL_newlib(L, dblib); 443 return 1; 444 } 445 446