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