ceph/src/lua/src/ldblib.c

   1 /*
   2 ** $Id: ldblib.c,v 1.151 2015/11/23 11:29:43 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