1 /* $NetBSD: ldblib.c,v 1.6 2015/10/08 12:40:05 mbalmer Exp $ */
2
3 /*
4 ** Id: ldblib.c,v 1.149 2015/02/19 17:06:21 roberto Exp
5 ** Interface from Lua to its debug API
6 ** See Copyright Notice in lua.h
7 */
8
9 #define ldblib_c
10 #define LUA_LIB
11
12 #include "lprefix.h"
13
14
15 #ifndef _KERNEL
16 #include <stdio.h>
17 #include <stdlib.h>
18 #include <string.h>
19 #endif
20
21 #include "lua.h"
22
23 #include "lauxlib.h"
24 #include "lualib.h"
25
26
27 /*
28 ** The hook table at registry[&HOOKKEY] maps threads to their current
29 ** hook function. (We only need the unique address of 'HOOKKEY'.)
30 */
31 static const int HOOKKEY = 0;
32
33
34 /*
35 ** If L1 != L, L1 can be in any state, and therefore there is no
36 ** garanties about its stack space; any push in L1 must be
37 ** checked.
38 */
checkstack(lua_State * L,lua_State * L1,int n)39 static void checkstack (lua_State *L, lua_State *L1, int n) {
40 if (L != L1 && !lua_checkstack(L1, n))
41 luaL_error(L, "stack overflow");
42 }
43
44
db_getregistry(lua_State * L)45 static int db_getregistry (lua_State *L) {
46 lua_pushvalue(L, LUA_REGISTRYINDEX);
47 return 1;
48 }
49
50
db_getmetatable(lua_State * L)51 static int db_getmetatable (lua_State *L) {
52 luaL_checkany(L, 1);
53 if (!lua_getmetatable(L, 1)) {
54 lua_pushnil(L); /* no metatable */
55 }
56 return 1;
57 }
58
59
db_setmetatable(lua_State * L)60 static int db_setmetatable (lua_State *L) {
61 int t = lua_type(L, 2);
62 luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
63 "nil or table expected");
64 lua_settop(L, 2);
65 lua_setmetatable(L, 1);
66 return 1; /* return 1st argument */
67 }
68
69
db_getuservalue(lua_State * L)70 static int db_getuservalue (lua_State *L) {
71 if (lua_type(L, 1) != LUA_TUSERDATA)
72 lua_pushnil(L);
73 else
74 lua_getuservalue(L, 1);
75 return 1;
76 }
77
78
db_setuservalue(lua_State * L)79 static int db_setuservalue (lua_State *L) {
80 luaL_checktype(L, 1, LUA_TUSERDATA);
81 luaL_checkany(L, 2);
82 lua_settop(L, 2);
83 lua_setuservalue(L, 1);
84 return 1;
85 }
86
87
88 /*
89 ** Auxiliary function used by several library functions: check for
90 ** an optional thread as function's first argument and set 'arg' with
91 ** 1 if this argument is present (so that functions can skip it to
92 ** access their other arguments)
93 */
getthread(lua_State * L,int * arg)94 static lua_State *getthread (lua_State *L, int *arg) {
95 if (lua_isthread(L, 1)) {
96 *arg = 1;
97 return lua_tothread(L, 1);
98 }
99 else {
100 *arg = 0;
101 return L; /* function will operate over current thread */
102 }
103 }
104
105
106 /*
107 ** Variations of 'lua_settable', used by 'db_getinfo' to put results
108 ** from 'lua_getinfo' into result table. Key is always a string;
109 ** value can be a string, an int, or a boolean.
110 */
settabss(lua_State * L,const char * k,const char * v)111 static void settabss (lua_State *L, const char *k, const char *v) {
112 lua_pushstring(L, v);
113 lua_setfield(L, -2, k);
114 }
115
settabsi(lua_State * L,const char * k,int v)116 static void settabsi (lua_State *L, const char *k, int v) {
117 lua_pushinteger(L, v);
118 lua_setfield(L, -2, k);
119 }
120
settabsb(lua_State * L,const char * k,int v)121 static void settabsb (lua_State *L, const char *k, int v) {
122 lua_pushboolean(L, v);
123 lua_setfield(L, -2, k);
124 }
125
126
127 /*
128 ** In function 'db_getinfo', the call to 'lua_getinfo' may push
129 ** results on the stack; later it creates the result table to put
130 ** these objects. Function 'treatstackoption' puts the result from
131 ** 'lua_getinfo' on top of the result table so that it can call
132 ** 'lua_setfield'.
133 */
treatstackoption(lua_State * L,lua_State * L1,const char * fname)134 static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) {
135 if (L == L1)
136 lua_rotate(L, -2, 1); /* exchange object and table */
137 else
138 lua_xmove(L1, L, 1); /* move object to the "main" stack */
139 lua_setfield(L, -2, fname); /* put object into table */
140 }
141
142
143 /*
144 ** Calls 'lua_getinfo' and collects all results in a new table.
145 ** L1 needs stack space for an optional input (function) plus
146 ** two optional outputs (function and line table) from function
147 ** 'lua_getinfo'.
148 */
db_getinfo(lua_State * L)149 static int db_getinfo (lua_State *L) {
150 lua_Debug ar;
151 int arg;
152 lua_State *L1 = getthread(L, &arg);
153 const char *options = luaL_optstring(L, arg+2, "flnStu");
154 checkstack(L, L1, 3);
155 if (lua_isfunction(L, arg + 1)) { /* info about a function? */
156 options = lua_pushfstring(L, ">%s", options); /* add '>' to 'options' */
157 lua_pushvalue(L, arg + 1); /* move function to 'L1' stack */
158 lua_xmove(L, L1, 1);
159 }
160 else { /* stack level */
161 if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) {
162 lua_pushnil(L); /* level out of range */
163 return 1;
164 }
165 }
166 if (!lua_getinfo(L1, options, &ar))
167 return luaL_argerror(L, arg+2, "invalid option");
168 lua_newtable(L); /* table to collect results */
169 if (strchr(options, 'S')) {
170 settabss(L, "source", ar.source);
171 settabss(L, "short_src", ar.short_src);
172 settabsi(L, "linedefined", ar.linedefined);
173 settabsi(L, "lastlinedefined", ar.lastlinedefined);
174 settabss(L, "what", ar.what);
175 }
176 if (strchr(options, 'l'))
177 settabsi(L, "currentline", ar.currentline);
178 if (strchr(options, 'u')) {
179 settabsi(L, "nups", ar.nups);
180 settabsi(L, "nparams", ar.nparams);
181 settabsb(L, "isvararg", ar.isvararg);
182 }
183 if (strchr(options, 'n')) {
184 settabss(L, "name", ar.name);
185 settabss(L, "namewhat", ar.namewhat);
186 }
187 if (strchr(options, 't'))
188 settabsb(L, "istailcall", ar.istailcall);
189 if (strchr(options, 'L'))
190 treatstackoption(L, L1, "activelines");
191 if (strchr(options, 'f'))
192 treatstackoption(L, L1, "func");
193 return 1; /* return table */
194 }
195
196
db_getlocal(lua_State * L)197 static int db_getlocal (lua_State *L) {
198 int arg;
199 lua_State *L1 = getthread(L, &arg);
200 lua_Debug ar;
201 const char *name;
202 int nvar = (int)luaL_checkinteger(L, arg + 2); /* local-variable index */
203 if (lua_isfunction(L, arg + 1)) { /* function argument? */
204 lua_pushvalue(L, arg + 1); /* push function */
205 lua_pushstring(L, lua_getlocal(L, NULL, nvar)); /* push local name */
206 return 1; /* return only name (there is no value) */
207 }
208 else { /* stack-level argument */
209 int level = (int)luaL_checkinteger(L, arg + 1);
210 if (!lua_getstack(L1, level, &ar)) /* out of range? */
211 return luaL_argerror(L, arg+1, "level out of range");
212 checkstack(L, L1, 1);
213 name = lua_getlocal(L1, &ar, nvar);
214 if (name) {
215 lua_xmove(L1, L, 1); /* move local value */
216 lua_pushstring(L, name); /* push name */
217 lua_rotate(L, -2, 1); /* re-order */
218 return 2;
219 }
220 else {
221 lua_pushnil(L); /* no name (nor value) */
222 return 1;
223 }
224 }
225 }
226
227
db_setlocal(lua_State * L)228 static int db_setlocal (lua_State *L) {
229 int arg;
230 const char *name;
231 lua_State *L1 = getthread(L, &arg);
232 lua_Debug ar;
233 int level = (int)luaL_checkinteger(L, arg + 1);
234 int nvar = (int)luaL_checkinteger(L, arg + 2);
235 if (!lua_getstack(L1, level, &ar)) /* out of range? */
236 return luaL_argerror(L, arg+1, "level out of range");
237 luaL_checkany(L, arg+3);
238 lua_settop(L, arg+3);
239 checkstack(L, L1, 1);
240 lua_xmove(L, L1, 1);
241 name = lua_setlocal(L1, &ar, nvar);
242 if (name == NULL)
243 lua_pop(L1, 1); /* pop value (if not popped by 'lua_setlocal') */
244 lua_pushstring(L, name);
245 return 1;
246 }
247
248
249 /*
250 ** get (if 'get' is true) or set an upvalue from a closure
251 */
auxupvalue(lua_State * L,int get)252 static int auxupvalue (lua_State *L, int get) {
253 const char *name;
254 int n = (int)luaL_checkinteger(L, 2); /* upvalue index */
255 luaL_checktype(L, 1, LUA_TFUNCTION); /* closure */
256 name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
257 if (name == NULL) return 0;
258 lua_pushstring(L, name);
259 lua_insert(L, -(get+1)); /* no-op if get is false */
260 return get + 1;
261 }
262
263
db_getupvalue(lua_State * L)264 static int db_getupvalue (lua_State *L) {
265 return auxupvalue(L, 1);
266 }
267
268
db_setupvalue(lua_State * L)269 static int db_setupvalue (lua_State *L) {
270 luaL_checkany(L, 3);
271 return auxupvalue(L, 0);
272 }
273
274
275 /*
276 ** Check whether a given upvalue from a given closure exists and
277 ** returns its index
278 */
checkupval(lua_State * L,int argf,int argnup)279 static int checkupval (lua_State *L, int argf, int argnup) {
280 int nup = (int)luaL_checkinteger(L, argnup); /* upvalue index */
281 luaL_checktype(L, argf, LUA_TFUNCTION); /* closure */
282 luaL_argcheck(L, (lua_getupvalue(L, argf, nup) != NULL), argnup,
283 "invalid upvalue index");
284 return nup;
285 }
286
287
db_upvalueid(lua_State * L)288 static int db_upvalueid (lua_State *L) {
289 int n = checkupval(L, 1, 2);
290 lua_pushlightuserdata(L, lua_upvalueid(L, 1, n));
291 return 1;
292 }
293
294
db_upvaluejoin(lua_State * L)295 static int db_upvaluejoin (lua_State *L) {
296 int n1 = checkupval(L, 1, 2);
297 int n2 = checkupval(L, 3, 4);
298 luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected");
299 luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected");
300 lua_upvaluejoin(L, 1, n1, 3, n2);
301 return 0;
302 }
303
304
305 /*
306 ** Call hook function registered at hook table for the current
307 ** thread (if there is one)
308 */
hookf(lua_State * L,lua_Debug * ar)309 static void hookf (lua_State *L, lua_Debug *ar) {
310 static const char *const hooknames[] =
311 {"call", "return", "line", "count", "tail call"};
312 lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY);
313 lua_pushthread(L);
314 if (lua_rawget(L, -2) == LUA_TFUNCTION) { /* is there a hook function? */
315 lua_pushstring(L, hooknames[(int)ar->event]); /* push event name */
316 if (ar->currentline >= 0)
317 lua_pushinteger(L, ar->currentline); /* push current line */
318 else lua_pushnil(L);
319 lua_assert(lua_getinfo(L, "lS", ar));
320 lua_call(L, 2, 0); /* call hook function */
321 }
322 }
323
324
325 /*
326 ** Convert a string mask (for 'sethook') into a bit mask
327 */
makemask(const char * smask,int count)328 static int makemask (const char *smask, int count) {
329 int mask = 0;
330 if (strchr(smask, 'c')) mask |= LUA_MASKCALL;
331 if (strchr(smask, 'r')) mask |= LUA_MASKRET;
332 if (strchr(smask, 'l')) mask |= LUA_MASKLINE;
333 if (count > 0) mask |= LUA_MASKCOUNT;
334 return mask;
335 }
336
337
338 /*
339 ** Convert a bit mask (for 'gethook') into a string mask
340 */
unmakemask(int mask,char * smask)341 static char *unmakemask (int mask, char *smask) {
342 int i = 0;
343 if (mask & LUA_MASKCALL) smask[i++] = 'c';
344 if (mask & LUA_MASKRET) smask[i++] = 'r';
345 if (mask & LUA_MASKLINE) smask[i++] = 'l';
346 smask[i] = '\0';
347 return smask;
348 }
349
350
db_sethook(lua_State * L)351 static int db_sethook (lua_State *L) {
352 int arg, mask, count;
353 lua_Hook func;
354 lua_State *L1 = getthread(L, &arg);
355 if (lua_isnoneornil(L, arg+1)) { /* no hook? */
356 lua_settop(L, arg+1);
357 func = NULL; mask = 0; count = 0; /* turn off hooks */
358 }
359 else {
360 const char *smask = luaL_checkstring(L, arg+2);
361 luaL_checktype(L, arg+1, LUA_TFUNCTION);
362 count = (int)luaL_optinteger(L, arg + 3, 0);
363 func = hookf; mask = makemask(smask, count);
364 }
365 if (lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY) == LUA_TNIL) {
366 lua_createtable(L, 0, 2); /* create a hook table */
367 lua_pushvalue(L, -1);
368 lua_rawsetp(L, LUA_REGISTRYINDEX, &HOOKKEY); /* set it in position */
369 lua_pushstring(L, "k");
370 lua_setfield(L, -2, "__mode"); /** hooktable.__mode = "k" */
371 lua_pushvalue(L, -1);
372 lua_setmetatable(L, -2); /* setmetatable(hooktable) = hooktable */
373 }
374 checkstack(L, L1, 1);
375 lua_pushthread(L1); lua_xmove(L1, L, 1); /* key (thread) */
376 lua_pushvalue(L, arg + 1); /* value (hook function) */
377 lua_rawset(L, -3); /* hooktable[L1] = new Lua hook */
378 lua_sethook(L1, func, mask, count);
379 return 0;
380 }
381
382
db_gethook(lua_State * L)383 static int db_gethook (lua_State *L) {
384 int arg;
385 lua_State *L1 = getthread(L, &arg);
386 char buff[5];
387 int mask = lua_gethookmask(L1);
388 lua_Hook hook = lua_gethook(L1);
389 if (hook == NULL) /* no hook? */
390 lua_pushnil(L);
391 else if (hook != hookf) /* external hook? */
392 lua_pushliteral(L, "external hook");
393 else { /* hook table must exist */
394 lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY);
395 checkstack(L, L1, 1);
396 lua_pushthread(L1); lua_xmove(L1, L, 1);
397 lua_rawget(L, -2); /* 1st result = hooktable[L1] */
398 lua_remove(L, -2); /* remove hook table */
399 }
400 lua_pushstring(L, unmakemask(mask, buff)); /* 2nd result = mask */
401 lua_pushinteger(L, lua_gethookcount(L1)); /* 3rd result = count */
402 return 3;
403 }
404
405
406 #ifndef _KERNEL
db_debug(lua_State * L)407 static int db_debug (lua_State *L) {
408 for (;;) {
409 char buffer[250];
410 lua_writestringerror("%s", "lua_debug> ");
411 if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
412 strcmp(buffer, "cont\n") == 0)
413 return 0;
414 if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
415 lua_pcall(L, 0, 0, 0))
416 lua_writestringerror("%s\n", lua_tostring(L, -1));
417 lua_settop(L, 0); /* remove eventual returns */
418 }
419 }
420 #endif
421
422
db_traceback(lua_State * L)423 static int db_traceback (lua_State *L) {
424 int arg;
425 lua_State *L1 = getthread(L, &arg);
426 const char *msg = lua_tostring(L, arg + 1);
427 if (msg == NULL && !lua_isnoneornil(L, arg + 1)) /* non-string 'msg'? */
428 lua_pushvalue(L, arg + 1); /* return it untouched */
429 else {
430 int level = (int)luaL_optinteger(L, arg + 2, (L == L1) ? 1 : 0);
431 luaL_traceback(L, L1, msg, level);
432 }
433 return 1;
434 }
435
436
437 static const luaL_Reg dblib[] = {
438 #ifndef _KERNEL
439 {"debug", db_debug},
440 #endif
441 {"getuservalue", db_getuservalue},
442 {"gethook", db_gethook},
443 {"getinfo", db_getinfo},
444 {"getlocal", db_getlocal},
445 {"getregistry", db_getregistry},
446 {"getmetatable", db_getmetatable},
447 {"getupvalue", db_getupvalue},
448 {"upvaluejoin", db_upvaluejoin},
449 {"upvalueid", db_upvalueid},
450 {"setuservalue", db_setuservalue},
451 {"sethook", db_sethook},
452 {"setlocal", db_setlocal},
453 {"setmetatable", db_setmetatable},
454 {"setupvalue", db_setupvalue},
455 {"traceback", db_traceback},
456 {NULL, NULL}
457 };
458
459
luaopen_debug(lua_State * L)460 LUAMOD_API int luaopen_debug (lua_State *L) {
461 luaL_newlib(L, dblib);
462 return 1;
463 }
464
465