ref: b569724604d5cae4611894aefde5578333e95f22
dir: /ldblib.c/
/* ** $Id: ldblib.c $ ** Interface from Lua to its debug API ** See Copyright Notice in lua.h */ #define ldblib_c #define LUA_LIB #include "lprefix.h" #include <stdio.h> #include <stdlib.h> #include <string.h> #include "lua.h" #include "lauxlib.h" #include "lualib.h" /* ** The hook table at registry[HOOKKEY] maps threads to their current ** hook function. */ static const char *const HOOKKEY = "_HOOKKEY"; /* ** If L1 != L, L1 can be in any state, and therefore there are no ** guarantees about its stack space; any push in L1 must be ** checked. */ static void checkstack (lua_State *L, lua_State *L1, int n) { if (L != L1 && !lua_checkstack(L1, n)) luaL_error(L, "stack overflow"); } static int db_getregistry (lua_State *L) { lua_pushvalue(L, LUA_REGISTRYINDEX); return 1; } static int db_getmetatable (lua_State *L) { luaL_checkany(L, 1); if (!lua_getmetatable(L, 1)) { lua_pushnil(L); /* no metatable */ } return 1; } static int db_setmetatable (lua_State *L) { int t = lua_type(L, 2); luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table"); lua_settop(L, 2); lua_setmetatable(L, 1); return 1; /* return 1st argument */ } static int db_getuservalue (lua_State *L) { int n = (int)luaL_optinteger(L, 2, 1); if (lua_type(L, 1) != LUA_TUSERDATA) luaL_pushfail(L); else if (lua_getiuservalue(L, 1, n) != LUA_TNONE) { lua_pushboolean(L, 1); return 2; } return 1; } static int db_setuservalue (lua_State *L) { int n = (int)luaL_optinteger(L, 3, 1); luaL_checktype(L, 1, LUA_TUSERDATA); luaL_checkany(L, 2); lua_settop(L, 2); if (!lua_setiuservalue(L, 1, n)) luaL_pushfail(L); return 1; } /* ** Auxiliary function used by several library functions: check for ** an optional thread as function's first argument and set 'arg' with ** 1 if this argument is present (so that functions can skip it to ** access their other arguments) */ static lua_State *getthread (lua_State *L, int *arg) { if (lua_isthread(L, 1)) { *arg = 1; return lua_tothread(L, 1); } else { *arg = 0; return L; /* function will operate over current thread */ } } /* ** Variations of 'lua_settable', used by 'db_getinfo' to put results ** from 'lua_getinfo' into result table. Key is always a string; ** value can be a string, an int, or a boolean. */ static void settabss (lua_State *L, const char *k, const char *v) { lua_pushstring(L, v); lua_setfield(L, -2, k); } static void settabsi (lua_State *L, const char *k, int v) { lua_pushinteger(L, v); lua_setfield(L, -2, k); } static void settabsb (lua_State *L, const char *k, int v) { lua_pushboolean(L, v); lua_setfield(L, -2, k); } /* ** In function 'db_getinfo', the call to 'lua_getinfo' may push ** results on the stack; later it creates the result table to put ** these objects. Function 'treatstackoption' puts the result from ** 'lua_getinfo' on top of the result table so that it can call ** 'lua_setfield'. */ static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) { if (L == L1) lua_rotate(L, -2, 1); /* exchange object and table */ else lua_xmove(L1, L, 1); /* move object to the "main" stack */ lua_setfield(L, -2, fname); /* put object into table */ } /* ** Calls 'lua_getinfo' and collects all results in a new table. ** L1 needs stack space for an optional input (function) plus ** two optional outputs (function and line table) from function ** 'lua_getinfo'. */ static int db_getinfo (lua_State *L) { lua_Debug ar; int arg; lua_State *L1 = getthread(L, &arg); const char *options = luaL_optstring(L, arg+2, "flnSrtu"); checkstack(L, L1, 3); if (lua_isfunction(L, arg + 1)) { /* info about a function? */ options = lua_pushfstring(L, ">%s", options); /* add '>' to 'options' */ lua_pushvalue(L, arg + 1); /* move function to 'L1' stack */ lua_xmove(L, L1, 1); } else { /* stack level */ if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) { luaL_pushfail(L); /* level out of range */ return 1; } } if (!lua_getinfo(L1, options, &ar)) return luaL_argerror(L, arg+2, "invalid option"); lua_newtable(L); /* table to collect results */ if (strchr(options, 'S')) { lua_pushlstring(L, ar.source, ar.srclen); lua_setfield(L, -2, "source"); settabss(L, "short_src", ar.short_src); settabsi(L, "linedefined", ar.linedefined); settabsi(L, "lastlinedefined", ar.lastlinedefined); settabss(L, "what", ar.what); } if (strchr(options, 'l')) settabsi(L, "currentline", ar.currentline); if (strchr(options, 'u')) { settabsi(L, "nups", ar.nups); settabsi(L, "nparams", ar.nparams); settabsb(L, "isvararg", ar.isvararg); } if (strchr(options, 'n')) { settabss(L, "name", ar.name); settabss(L, "namewhat", ar.namewhat); } if (strchr(options, 'r')) { settabsi(L, "ftransfer", ar.ftransfer); settabsi(L, "ntransfer", ar.ntransfer); } if (strchr(options, 't')) settabsb(L, "istailcall", ar.istailcall); if (strchr(options, 'L')) treatstackoption(L, L1, "activelines"); if (strchr(options, 'f')) treatstackoption(L, L1, "func"); return 1; /* return table */ } static int db_getlocal (lua_State *L) { int arg; lua_State *L1 = getthread(L, &arg); int nvar = (int)luaL_checkinteger(L, arg + 2); /* local-variable index */ if (lua_isfunction(L, arg + 1)) { /* function argument? */ lua_pushvalue(L, arg + 1); /* push function */ lua_pushstring(L, lua_getlocal(L, NULL, nvar)); /* push local name */ return 1; /* return only name (there is no value) */ } else { /* stack-level argument */ lua_Debug ar; const char *name; int level = (int)luaL_checkinteger(L, arg + 1); if (!lua_getstack(L1, level, &ar)) /* out of range? */ return luaL_argerror(L, arg+1, "level out of range"); checkstack(L, L1, 1); name = lua_getlocal(L1, &ar, nvar); if (name) { lua_xmove(L1, L, 1); /* move local value */ lua_pushstring(L, name); /* push name */ lua_rotate(L, -2, 1); /* re-order */ return 2; } else { luaL_pushfail(L); /* no name (nor value) */ return 1; } } } static int db_setlocal (lua_State *L) { int arg; const char *name; lua_State *L1 = getthread(L, &arg); lua_Debug ar; int level = (int)luaL_checkinteger(L, arg + 1); int nvar = (int)luaL_checkinteger(L, arg + 2); if (!lua_getstack(L1, level, &ar)) /* out of range? */ return luaL_argerror(L, arg+1, "level out of range"); luaL_checkany(L, arg+3); lua_settop(L, arg+3); checkstack(L, L1, 1); lua_xmove(L, L1, 1); name = lua_setlocal(L1, &ar, nvar); if (name == NULL) lua_pop(L1, 1); /* pop value (if not popped by 'lua_setlocal') */ lua_pushstring(L, name); return 1; } /* ** get (if 'get' is true) or set an upvalue from a closure */ static int auxupvalue (lua_State *L, int get) { const char *name; int n = (int)luaL_checkinteger(L, 2); /* upvalue index */ luaL_checktype(L, 1, LUA_TFUNCTION); /* closure */ name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n); if (name == NULL) return 0; lua_pushstring(L, name); lua_insert(L, -(get+1)); /* no-op if get is false */ return get + 1; } static int db_getupvalue (lua_State *L) { return auxupvalue(L, 1); } static int db_setupvalue (lua_State *L) { luaL_checkany(L, 3); return auxupvalue(L, 0); } /* ** Check whether a given upvalue from a given closure exists and ** returns its index */ static void *checkupval (lua_State *L, int argf, int argnup, int *pnup) { void *id; int nup = (int)luaL_checkinteger(L, argnup); /* upvalue index */ luaL_checktype(L, argf, LUA_TFUNCTION); /* closure */ id = lua_upvalueid(L, argf, nup); if (pnup) { luaL_argcheck(L, id != NULL, argnup, "invalid upvalue index"); *pnup = nup; } return id; } static int db_upvalueid (lua_State *L) { void *id = checkupval(L, 1, 2, NULL); if (id != NULL) lua_pushlightuserdata(L, id); else luaL_pushfail(L); return 1; } static int db_upvaluejoin (lua_State *L) { int n1, n2; checkupval(L, 1, 2, &n1); checkupval(L, 3, 4, &n2); luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected"); luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected"); lua_upvaluejoin(L, 1, n1, 3, n2); return 0; } /* ** Call hook function registered at hook table for the current ** thread (if there is one) */ static void hookf (lua_State *L, lua_Debug *ar) { static const char *const hooknames[] = {"call", "return", "line", "count", "tail call"}; lua_getfield(L, LUA_REGISTRYINDEX, HOOKKEY); lua_pushthread(L); if (lua_rawget(L, -2) == LUA_TFUNCTION) { /* is there a hook function? */ lua_pushstring(L, hooknames[(int)ar->event]); /* push event name */ if (ar->currentline >= 0) lua_pushinteger(L, ar->currentline); /* push current line */ else lua_pushnil(L); lua_assert(lua_getinfo(L, "lS", ar)); lua_call(L, 2, 0); /* call hook function */ } } /* ** Convert a string mask (for 'sethook') into a bit mask */ static int makemask (const char *smask, int count) { int mask = 0; if (strchr(smask, 'c')) mask |= LUA_MASKCALL; if (strchr(smask, 'r')) mask |= LUA_MASKRET; if (strchr(smask, 'l')) mask |= LUA_MASKLINE; if (count > 0) mask |= LUA_MASKCOUNT; return mask; } /* ** Convert a bit mask (for 'gethook') into a string mask */ static char *unmakemask (int mask, char *smask) { int i = 0; if (mask & LUA_MASKCALL) smask[i++] = 'c'; if (mask & LUA_MASKRET) smask[i++] = 'r'; if (mask & LUA_MASKLINE) smask[i++] = 'l'; smask[i] = '\0'; return smask; } static int db_sethook (lua_State *L) { int arg, mask, count; lua_Hook func; lua_State *L1 = getthread(L, &arg); if (lua_isnoneornil(L, arg+1)) { /* no hook? */ lua_settop(L, arg+1); func = NULL; mask = 0; count = 0; /* turn off hooks */ } else { const char *smask = luaL_checkstring(L, arg+2); luaL_checktype(L, arg+1, LUA_TFUNCTION); count = (int)luaL_optinteger(L, arg + 3, 0); func = hookf; mask = makemask(smask, count); } if (!luaL_getsubtable(L, LUA_REGISTRYINDEX, HOOKKEY)) { /* table just created; initialize it */ lua_pushstring(L, "k"); lua_setfield(L, -2, "__mode"); /** hooktable.__mode = "k" */ lua_pushvalue(L, -1); lua_setmetatable(L, -2); /* metatable(hooktable) = hooktable */ } checkstack(L, L1, 1); lua_pushthread(L1); lua_xmove(L1, L, 1); /* key (thread) */ lua_pushvalue(L, arg + 1); /* value (hook function) */ lua_rawset(L, -3); /* hooktable[L1] = new Lua hook */ lua_sethook(L1, func, mask, count); return 0; } static int db_gethook (lua_State *L) { int arg; lua_State *L1 = getthread(L, &arg); char buff[5]; int mask = lua_gethookmask(L1); lua_Hook hook = lua_gethook(L1); if (hook == NULL) { /* no hook? */ luaL_pushfail(L); return 1; } else if (hook != hookf) /* external hook? */ lua_pushliteral(L, "external hook"); else { /* hook table must exist */ lua_getfield(L, LUA_REGISTRYINDEX, HOOKKEY); checkstack(L, L1, 1); lua_pushthread(L1); lua_xmove(L1, L, 1); lua_rawget(L, -2); /* 1st result = hooktable[L1] */ lua_remove(L, -2); /* remove hook table */ } lua_pushstring(L, unmakemask(mask, buff)); /* 2nd result = mask */ lua_pushinteger(L, lua_gethookcount(L1)); /* 3rd result = count */ return 3; } static int db_debug (lua_State *L) { for (;;) { char buffer[250]; lua_writestringerror("%s", "lua_debug> "); if (fgets(buffer, sizeof(buffer), stdin) == 0 || strcmp(buffer, "cont\n") == 0) return 0; if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") || lua_pcall(L, 0, 0, 0)) lua_writestringerror("%s\n", luaL_tolstring(L, -1, NULL)); lua_settop(L, 0); /* remove eventual returns */ } } static int db_traceback (lua_State *L) { int arg; lua_State *L1 = getthread(L, &arg); const char *msg = lua_tostring(L, arg + 1); if (msg == NULL && !lua_isnoneornil(L, arg + 1)) /* non-string 'msg'? */ lua_pushvalue(L, arg + 1); /* return it untouched */ else { int level = (int)luaL_optinteger(L, arg + 2, (L == L1) ? 1 : 0); luaL_traceback(L, L1, msg, level); } return 1; } static int db_setcstacklimit (lua_State *L) { int limit = (int)luaL_checkinteger(L, 1); int res = lua_setcstacklimit(L, limit); lua_pushinteger(L, res); return 1; } static const luaL_Reg dblib[] = { {"debug", db_debug}, {"getuservalue", db_getuservalue}, {"gethook", db_gethook}, {"getinfo", db_getinfo}, {"getlocal", db_getlocal}, {"getregistry", db_getregistry}, {"getmetatable", db_getmetatable}, {"getupvalue", db_getupvalue}, {"upvaluejoin", db_upvaluejoin}, {"upvalueid", db_upvalueid}, {"setuservalue", db_setuservalue}, {"sethook", db_sethook}, {"setlocal", db_setlocal}, {"setmetatable", db_setmetatable}, {"setupvalue", db_setupvalue}, {"traceback", db_traceback}, {"setcstacklimit", db_setcstacklimit}, {NULL, NULL} }; LUAMOD_API int luaopen_debug (lua_State *L) { luaL_newlib(L, dblib); return 1; }