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