1 /*
2 ** $Id$
3 ** Interface from Lua to its debug API
4 ** See Copyright Notice in lua.h
5 */
6
7 #define FORBIDDEN_SYMBOL_EXCEPTION_stdin
8 #define FORBIDDEN_SYMBOL_EXCEPTION_stderr
9 #define FORBIDDEN_SYMBOL_EXCEPTION_fputs
10 #define FORBIDDEN_SYMBOL_EXCEPTION_fgets
11
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <string.h>
15
16 #define ldblib_c
17 #define LUA_LIB
18
19 #include "lua.h"
20
21 #include "lauxlib.h"
22 #include "lualib.h"
23
24
25
db_getregistry(lua_State * L)26 static int db_getregistry (lua_State *L) {
27 lua_pushvalue(L, LUA_REGISTRYINDEX);
28 return 1;
29 }
30
31
db_getmetatable(lua_State * L)32 static int db_getmetatable (lua_State *L) {
33 luaL_checkany(L, 1);
34 if (!lua_getmetatable(L, 1)) {
35 lua_pushnil(L); /* no metatable */
36 }
37 return 1;
38 }
39
40
db_setmetatable(lua_State * L)41 static int db_setmetatable (lua_State *L) {
42 int t = lua_type(L, 2);
43 luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
44 "nil or table expected");
45 lua_settop(L, 2);
46 lua_pushboolean(L, lua_setmetatable(L, 1));
47 return 1;
48 }
49
50
db_getfenv(lua_State * L)51 static int db_getfenv (lua_State *L) {
52 lua_getfenv(L, 1);
53 return 1;
54 }
55
56
db_setfenv(lua_State * L)57 static int db_setfenv (lua_State *L) {
58 luaL_checktype(L, 2, LUA_TTABLE);
59 lua_settop(L, 2);
60 if (lua_setfenv(L, 1) == 0)
61 luaL_error(L, LUA_QL("setfenv")
62 " cannot change environment of given object");
63 return 1;
64 }
65
66
settabss(lua_State * L,const char * i,const char * v)67 static void settabss (lua_State *L, const char *i, const char *v) {
68 lua_pushstring(L, v);
69 lua_setfield(L, -2, i);
70 }
71
72
settabsi(lua_State * L,const char * i,int v)73 static void settabsi (lua_State *L, const char *i, int v) {
74 lua_pushinteger(L, v);
75 lua_setfield(L, -2, i);
76 }
77
78
getthread(lua_State * L,int * arg)79 static lua_State *getthread (lua_State *L, int *arg) {
80 if (lua_isthread(L, 1)) {
81 *arg = 1;
82 return lua_tothread(L, 1);
83 }
84 else {
85 *arg = 0;
86 return L;
87 }
88 }
89
90
treatstackoption(lua_State * L,lua_State * L1,const char * fname)91 static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) {
92 if (L == L1) {
93 lua_pushvalue(L, -2);
94 lua_remove(L, -3);
95 }
96 else
97 lua_xmove(L1, L, 1);
98 lua_setfield(L, -2, fname);
99 }
100
101
db_getinfo(lua_State * L)102 static int db_getinfo (lua_State *L) {
103 lua_Debug ar;
104 int arg;
105 lua_State *L1 = getthread(L, &arg);
106 const char *options = luaL_optstring(L, arg+2, "flnSu");
107 if (lua_isnumber(L, arg+1)) {
108 if (!lua_getstack(L1, (int)lua_tointeger(L, arg+1), &ar)) {
109 lua_pushnil(L); /* level out of range */
110 return 1;
111 }
112 }
113 else if (lua_isfunction(L, arg+1)) {
114 lua_pushfstring(L, ">%s", options);
115 options = lua_tostring(L, -1);
116 lua_pushvalue(L, arg+1);
117 lua_xmove(L, L1, 1);
118 }
119 else
120 return luaL_argerror(L, arg+1, "function or level expected");
121 if (!lua_getinfo(L1, options, &ar))
122 return luaL_argerror(L, arg+2, "invalid option");
123 lua_createtable(L, 0, 2);
124 if (strchr(options, 'S')) {
125 settabss(L, "source", ar.source);
126 settabss(L, "short_src", ar.short_src);
127 settabsi(L, "linedefined", ar.linedefined);
128 settabsi(L, "lastlinedefined", ar.lastlinedefined);
129 settabss(L, "what", ar.what);
130 }
131 if (strchr(options, 'l'))
132 settabsi(L, "currentline", ar.currentline);
133 if (strchr(options, 'u'))
134 settabsi(L, "nups", ar.nups);
135 if (strchr(options, 'n')) {
136 settabss(L, "name", ar.name);
137 settabss(L, "namewhat", ar.namewhat);
138 }
139 if (strchr(options, 'L'))
140 treatstackoption(L, L1, "activelines");
141 if (strchr(options, 'f'))
142 treatstackoption(L, L1, "func");
143 return 1; /* return table */
144 }
145
146
db_getlocal(lua_State * L)147 static int db_getlocal (lua_State *L) {
148 int arg;
149 lua_State *L1 = getthread(L, &arg);
150 lua_Debug ar;
151 const char *name;
152 if (!lua_getstack(L1, luaL_checkint(L, arg+1), &ar)) /* out of range? */
153 return luaL_argerror(L, arg+1, "level out of range");
154 name = lua_getlocal(L1, &ar, luaL_checkint(L, arg+2));
155 if (name) {
156 lua_xmove(L1, L, 1);
157 lua_pushstring(L, name);
158 lua_pushvalue(L, -2);
159 return 2;
160 }
161 else {
162 lua_pushnil(L);
163 return 1;
164 }
165 }
166
167
db_setlocal(lua_State * L)168 static int db_setlocal (lua_State *L) {
169 int arg;
170 lua_State *L1 = getthread(L, &arg);
171 lua_Debug ar;
172 if (!lua_getstack(L1, luaL_checkint(L, arg+1), &ar)) /* out of range? */
173 return luaL_argerror(L, arg+1, "level out of range");
174 luaL_checkany(L, arg+3);
175 lua_settop(L, arg+3);
176 lua_xmove(L, L1, 1);
177 lua_pushstring(L, lua_setlocal(L1, &ar, luaL_checkint(L, arg+2)));
178 return 1;
179 }
180
181
auxupvalue(lua_State * L,int get)182 static int auxupvalue (lua_State *L, int get) {
183 const char *name;
184 int n = luaL_checkint(L, 2);
185 luaL_checktype(L, 1, LUA_TFUNCTION);
186 if (lua_iscfunction(L, 1)) return 0; /* cannot touch C upvalues from Lua */
187 name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
188 if (name == NULL) return 0;
189 lua_pushstring(L, name);
190 lua_insert(L, -(get+1));
191 return get + 1;
192 }
193
194
db_getupvalue(lua_State * L)195 static int db_getupvalue (lua_State *L) {
196 return auxupvalue(L, 1);
197 }
198
199
db_setupvalue(lua_State * L)200 static int db_setupvalue (lua_State *L) {
201 luaL_checkany(L, 3);
202 return auxupvalue(L, 0);
203 }
204
205
206
207 static /*const*/ char KEY_HOOK = 'h';
208
209
hookf(lua_State * L,lua_Debug * ar)210 static void hookf (lua_State *L, lua_Debug *ar) {
211 static const char *const hooknames[] =
212 {"call", "return", "line", "count", "tail return"};
213 lua_pushlightuserdata(L, (void *)&KEY_HOOK);
214 lua_rawget(L, LUA_REGISTRYINDEX);
215 lua_pushlightuserdata(L, L);
216 lua_rawget(L, -2);
217 if (lua_isfunction(L, -1)) {
218 lua_pushstring(L, hooknames[(int)ar->event]);
219 if (ar->currentline >= 0)
220 lua_pushinteger(L, ar->currentline);
221 else lua_pushnil(L);
222 lua_assert(lua_getinfo(L, "lS", ar));
223 lua_call(L, 2, 0);
224 }
225 }
226
227
makemask(const char * smask,int count)228 static int makemask (const char *smask, int count) {
229 int mask = 0;
230 if (strchr(smask, 'c')) mask |= LUA_MASKCALL;
231 if (strchr(smask, 'r')) mask |= LUA_MASKRET;
232 if (strchr(smask, 'l')) mask |= LUA_MASKLINE;
233 if (count > 0) mask |= LUA_MASKCOUNT;
234 return mask;
235 }
236
237
unmakemask(int mask,char * smask)238 static char *unmakemask (int mask, char *smask) {
239 int i = 0;
240 if (mask & LUA_MASKCALL) smask[i++] = 'c';
241 if (mask & LUA_MASKRET) smask[i++] = 'r';
242 if (mask & LUA_MASKLINE) smask[i++] = 'l';
243 smask[i] = '\0';
244 return smask;
245 }
246
247
gethooktable(lua_State * L)248 static void gethooktable (lua_State *L) {
249 lua_pushlightuserdata(L, (void *)&KEY_HOOK);
250 lua_rawget(L, LUA_REGISTRYINDEX);
251 if (!lua_istable(L, -1)) {
252 lua_pop(L, 1);
253 lua_createtable(L, 0, 1);
254 lua_pushlightuserdata(L, (void *)&KEY_HOOK);
255 lua_pushvalue(L, -2);
256 lua_rawset(L, LUA_REGISTRYINDEX);
257 }
258 }
259
260
db_sethook(lua_State * L)261 static int db_sethook (lua_State *L) {
262 int arg, mask, count;
263 lua_Hook func;
264 lua_State *L1 = getthread(L, &arg);
265 if (lua_isnoneornil(L, arg+1)) {
266 lua_settop(L, arg+1);
267 func = NULL; mask = 0; count = 0; /* turn off hooks */
268 }
269 else {
270 const char *smask = luaL_checkstring(L, arg+2);
271 luaL_checktype(L, arg+1, LUA_TFUNCTION);
272 count = luaL_optint(L, arg+3, 0);
273 func = hookf; mask = makemask(smask, count);
274 }
275 gethooktable(L);
276 lua_pushlightuserdata(L, L1);
277 lua_pushvalue(L, arg+1);
278 lua_rawset(L, -3); /* set new hook */
279 lua_pop(L, 1); /* remove hook table */
280 lua_sethook(L1, func, mask, count); /* set hooks */
281 return 0;
282 }
283
284
db_gethook(lua_State * L)285 static int db_gethook (lua_State *L) {
286 int arg;
287 lua_State *L1 = getthread(L, &arg);
288 char buff[5];
289 int mask = lua_gethookmask(L1);
290 lua_Hook hook = lua_gethook(L1);
291 if (hook != NULL && hook != hookf) /* external hook? */
292 lua_pushliteral(L, "external hook");
293 else {
294 gethooktable(L);
295 lua_pushlightuserdata(L, L1);
296 lua_rawget(L, -2); /* get hook */
297 lua_remove(L, -2); /* remove hook table */
298 }
299 lua_pushstring(L, unmakemask(mask, buff));
300 lua_pushinteger(L, lua_gethookcount(L1));
301 return 3;
302 }
303
304
db_debug(lua_State * L)305 static int db_debug (lua_State *L) {
306 for (;;) {
307 char buffer[250];
308 fputs("lua_debug> ", stderr);
309 if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
310 strcmp(buffer, "cont\n") == 0)
311 return 0;
312 if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
313 lua_pcall(L, 0, 0, 0)) {
314 fputs(lua_tostring(L, -1), stderr);
315 fputs("\n", stderr);
316 }
317 lua_settop(L, 0); /* remove eventual returns */
318 }
319 }
320
321
322 #define LEVELS1 12 /* size of the first part of the stack */
323 #define LEVELS2 10 /* size of the second part of the stack */
324
db_errorfb(lua_State * L)325 static int db_errorfb (lua_State *L) {
326 int level;
327 int firstpart = 1; /* still before eventual `...' */
328 int arg;
329 lua_State *L1 = getthread(L, &arg);
330 lua_Debug ar;
331 if (lua_isnumber(L, arg+2)) {
332 level = (int)lua_tointeger(L, arg+2);
333 lua_pop(L, 1);
334 }
335 else
336 level = (L == L1) ? 1 : 0; /* level 0 may be this own function */
337 if (lua_gettop(L) == arg)
338 lua_pushliteral(L, "");
339 else if (!lua_isstring(L, arg+1)) return 1; /* message is not a string */
340 else lua_pushliteral(L, "\n");
341 lua_pushliteral(L, "stack traceback:");
342 while (lua_getstack(L1, level++, &ar)) {
343 if (level > LEVELS1 && firstpart) {
344 /* no more than `LEVELS2' more levels? */
345 if (!lua_getstack(L1, level+LEVELS2, &ar))
346 level--; /* keep going */
347 else {
348 lua_pushliteral(L, "\n\t..."); /* too many levels */
349 while (lua_getstack(L1, level+LEVELS2, &ar)) /* find last levels */
350 level++;
351 }
352 firstpart = 0;
353 continue;
354 }
355 lua_pushliteral(L, "\n\t");
356 lua_getinfo(L1, "Snl", &ar);
357 lua_pushfstring(L, "%s:", ar.short_src);
358 if (ar.currentline > 0)
359 lua_pushfstring(L, "%d:", ar.currentline);
360 if (*ar.namewhat != '\0') /* is there a name? */
361 lua_pushfstring(L, " in function " LUA_QS, ar.name);
362 else {
363 if (*ar.what == 'm') /* main? */
364 lua_pushfstring(L, " in main chunk");
365 else if (*ar.what == 'C' || *ar.what == 't')
366 lua_pushliteral(L, " ?"); /* C function or tail call */
367 else
368 lua_pushfstring(L, " in function <%s:%d>",
369 ar.short_src, ar.linedefined);
370 }
371 lua_concat(L, lua_gettop(L) - arg);
372 }
373 lua_concat(L, lua_gettop(L) - arg);
374 return 1;
375 }
376
377
378 static const luaL_Reg dblib[] = {
379 {"debug", db_debug},
380 {"getfenv", db_getfenv},
381 {"gethook", db_gethook},
382 {"getinfo", db_getinfo},
383 {"getlocal", db_getlocal},
384 {"getregistry", db_getregistry},
385 {"getmetatable", db_getmetatable},
386 {"getupvalue", db_getupvalue},
387 {"setfenv", db_setfenv},
388 {"sethook", db_sethook},
389 {"setlocal", db_setlocal},
390 {"setmetatable", db_setmetatable},
391 {"setupvalue", db_setupvalue},
392 {"traceback", db_errorfb},
393 {NULL, NULL}
394 };
395
396
luaopen_debug(lua_State * L)397 LUALIB_API int luaopen_debug (lua_State *L) {
398 luaL_register(L, LUA_DBLIBNAME, dblib);
399 return 1;
400 }
401