1/*
2** $Id: ldblib.c,v 1.151.1.1 2017/04/19 17:20:42 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*/
27static const int HOOKKEY = 0;
28
29
30/*
31** If L1 != L, L1 can be in any state, and therefore there are no
32** guarantees about its stack space; any push in L1 must be
33** checked.
34*/
35static void checkstack (lua_State *L, lua_State *L1, int n) {
36 if (L != L1 && !lua_checkstack(L1, n))
37 luaL_error(L, "stack overflow");
38}
39
40
41static int db_getregistry (lua_State *L) {
42 lua_pushvalue(L, LUA_REGISTRYINDEX);
43 return 1;
44}
45
46
47static int db_getmetatable (lua_State *L) {
48 luaL_checkany(L, 1);
49 if (!lua_getmetatable(L, 1)) {
50 lua_pushnil(L); /* no metatable */
51 }
52 return 1;
53}
54
55
56static int db_setmetatable (lua_State *L) {
57 int t = lua_type(L, 2);
58 luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
59 "nil or table expected");
60 lua_settop(L, 2);
61 lua_setmetatable(L, 1);
62 return 1; /* return 1st argument */
63}
64
65
66static int db_getuservalue (lua_State *L) {
67 if (lua_type(L, 1) != LUA_TUSERDATA)
68 lua_pushnil(L);
69 else
70 lua_getuservalue(L, 1);
71 return 1;
72}
73
74
75static int db_setuservalue (lua_State *L) {
76 luaL_checktype(L, 1, LUA_TUSERDATA);
77 luaL_checkany(L, 2);
78 lua_settop(L, 2);
79 lua_setuservalue(L, 1);
80 return 1;
81}
82
83
84/*
85** Auxiliary function used by several library functions: check for
86** an optional thread as function's first argument and set 'arg' with
87** 1 if this argument is present (so that functions can skip it to
88** access their other arguments)
89*/
90static lua_State *getthread (lua_State *L, int *arg) {
91 if (lua_isthread(L, 1)) {
92 *arg = 1;
93 return lua_tothread(L, 1);
94 }
95 else {
96 *arg = 0;
97 return L; /* function will operate over current thread */
98 }
99}
100
101
102/*
103** Variations of 'lua_settable', used by 'db_getinfo' to put results
104** from 'lua_getinfo' into result table. Key is always a string;
105** value can be a string, an int, or a boolean.
106*/
107static void settabss (lua_State *L, const char *k, const char *v) {
108 lua_pushstring(L, v);
109 lua_setfield(L, -2, k);
110}
111
112static void settabsi (lua_State *L, const char *k, int v) {
113 lua_pushinteger(L, v);
114 lua_setfield(L, -2, k);
115}
116
117static void settabsb (lua_State *L, const char *k, int v) {
118 lua_pushboolean(L, v);
119 lua_setfield(L, -2, k);
120}
121
122
123/*
124** In function 'db_getinfo', the call to 'lua_getinfo' may push
125** results on the stack; later it creates the result table to put
126** these objects. Function 'treatstackoption' puts the result from
127** 'lua_getinfo' on top of the result table so that it can call
128** 'lua_setfield'.
129*/
130static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) {
131 if (L == L1)
132 lua_rotate(L, -2, 1); /* exchange object and table */
133 else
134 lua_xmove(L1, L, 1); /* move object to the "main" stack */
135 lua_setfield(L, -2, fname); /* put object into table */
136}
137
138
139/*
140** Calls 'lua_getinfo' and collects all results in a new table.
141** L1 needs stack space for an optional input (function) plus
142** two optional outputs (function and line table) from function
143** 'lua_getinfo'.
144*/
145static int db_getinfo (lua_State *L) {
146 lua_Debug ar;
147 int arg;
148 lua_State *L1 = getthread(L, &arg);
149 const char *options = luaL_optstring(L, arg+2, "flnStu");
150 checkstack(L, L1, 3);
151 if (lua_isfunction(L, arg + 1)) { /* info about a function? */
152 options = lua_pushfstring(L, ">%s", options); /* add '>' to 'options' */
153 lua_pushvalue(L, arg + 1); /* move function to 'L1' stack */
154 lua_xmove(L, L1, 1);
155 }
156 else { /* stack level */
157 if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) {
158 lua_pushnil(L); /* level out of range */
159 return 1;
160 }
161 }
162 if (!lua_getinfo(L1, options, &ar))
163 return luaL_argerror(L, arg+2, "invalid option");
164 lua_newtable(L); /* table to collect results */
165 if (strchr(options, 'S')) {
166 settabss(L, "source", ar.source);
167 settabss(L, "short_src", ar.short_src);
168 settabsi(L, "linedefined", ar.linedefined);
169 settabsi(L, "lastlinedefined", ar.lastlinedefined);
170 settabss(L, "what", ar.what);
171 }
172 if (strchr(options, 'l'))
173 settabsi(L, "currentline", ar.currentline);
174 if (strchr(options, 'u')) {
175 settabsi(L, "nups", ar.nups);
176 settabsi(L, "nparams", ar.nparams);
177 settabsb(L, "isvararg", ar.isvararg);
178 }
179 if (strchr(options, 'n')) {
180 settabss(L, "name", ar.name);
181 settabss(L, "namewhat", ar.namewhat);
182 }
183 if (strchr(options, 't'))
184 settabsb(L, "istailcall", ar.istailcall);
185 if (strchr(options, 'L'))
186 treatstackoption(L, L1, "activelines");
187 if (strchr(options, 'f'))
188 treatstackoption(L, L1, "func");
189 return 1; /* return table */
190}
191
192
193static int db_getlocal (lua_State *L) {
194 int arg;
195 lua_State *L1 = getthread(L, &arg);
196 lua_Debug ar;
197 const char *name;
198 int nvar = (int)luaL_checkinteger(L, arg + 2); /* local-variable index */
199 if (lua_isfunction(L, arg + 1)) { /* function argument? */
200 lua_pushvalue(L, arg + 1); /* push function */
201 lua_pushstring(L, lua_getlocal(L, NULL, nvar)); /* push local name */
202 return 1; /* return only name (there is no value) */
203 }
204 else { /* stack-level argument */
205 int level = (int)luaL_checkinteger(L, arg + 1);
206 if (!lua_getstack(L1, level, &ar)) /* out of range? */
207 return luaL_argerror(L, arg+1, "level out of range");
208 checkstack(L, L1, 1);
209 name = lua_getlocal(L1, &ar, nvar);
210 if (name) {
211 lua_xmove(L1, L, 1); /* move local value */
212 lua_pushstring(L, name); /* push name */
213 lua_rotate(L, -2, 1); /* re-order */
214 return 2;
215 }
216 else {
217 lua_pushnil(L); /* no name (nor value) */
218 return 1;
219 }
220 }
221}
222
223
224static int db_setlocal (lua_State *L) {
225 int arg;
226 const char *name;
227 lua_State *L1 = getthread(L, &arg);
228 lua_Debug ar;
229 int level = (int)luaL_checkinteger(L, arg + 1);
230 int nvar = (int)luaL_checkinteger(L, arg + 2);
231 if (!lua_getstack(L1, level, &ar)) /* out of range? */
232 return luaL_argerror(L, arg+1, "level out of range");
233 luaL_checkany(L, arg+3);
234 lua_settop(L, arg+3);
235 checkstack(L, L1, 1);
236 lua_xmove(L, L1, 1);
237 name = lua_setlocal(L1, &ar, nvar);
238 if (name == NULL)
239 lua_pop(L1, 1); /* pop value (if not popped by 'lua_setlocal') */
240 lua_pushstring(L, name);
241 return 1;
242}
243
244
245/*
246** get (if 'get' is true) or set an upvalue from a closure
247*/
248static int auxupvalue (lua_State *L, int get) {
249 const char *name;
250 int n = (int)luaL_checkinteger(L, 2); /* upvalue index */
251 luaL_checktype(L, 1, LUA_TFUNCTION); /* closure */
252 name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n);
253 if (name == NULL) return 0;
254 lua_pushstring(L, name);
255 lua_insert(L, -(get+1)); /* no-op if get is false */
256 return get + 1;
257}
258
259
260static int db_getupvalue (lua_State *L) {
261 return auxupvalue(L, 1);
262}
263
264
265static int db_setupvalue (lua_State *L) {
266 luaL_checkany(L, 3);
267 return auxupvalue(L, 0);
268}
269
270
271/*
272** Check whether a given upvalue from a given closure exists and
273** returns its index
274*/
275static int checkupval (lua_State *L, int argf, int argnup) {
276 int nup = (int)luaL_checkinteger(L, argnup); /* upvalue index */
277 luaL_checktype(L, argf, LUA_TFUNCTION); /* closure */
278 luaL_argcheck(L, (lua_getupvalue(L, argf, nup) != NULL), argnup,
279 "invalid upvalue index");
280 return nup;
281}
282
283
284static int db_upvalueid (lua_State *L) {
285 int n = checkupval(L, 1, 2);
286 lua_pushlightuserdata(L, lua_upvalueid(L, 1, n));
287 return 1;
288}
289
290
291static int db_upvaluejoin (lua_State *L) {
292 int n1 = checkupval(L, 1, 2);
293 int n2 = checkupval(L, 3, 4);
294 luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected");
295 luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected");
296 lua_upvaluejoin(L, 1, n1, 3, n2);
297 return 0;
298}
299
300
301/*
302** Call hook function registered at hook table for the current
303** thread (if there is one)
304*/
305static void hookf (lua_State *L, lua_Debug *ar) {
306 static const char *const hooknames[] =
307 {"call", "return", "line", "count", "tail call"};
308 lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY);
309 lua_pushthread(L);
310 if (lua_rawget(L, -2) == LUA_TFUNCTION) { /* is there a hook function? */
311 lua_pushstring(L, hooknames[(int)ar->event]); /* push event name */
312 if (ar->currentline >= 0)
313 lua_pushinteger(L, ar->currentline); /* push current line */
314 else lua_pushnil(L);
315 lua_assert(lua_getinfo(L, "lS", ar));
316 lua_call(L, 2, 0); /* call hook function */
317 }
318}
319
320
321/*
322** Convert a string mask (for 'sethook') into a bit mask
323*/
324static int makemask (const char *smask, int count) {
325 int mask = 0;
326 if (strchr(smask, 'c')) mask |= LUA_MASKCALL;
327 if (strchr(smask, 'r')) mask |= LUA_MASKRET;
328 if (strchr(smask, 'l')) mask |= LUA_MASKLINE;
329 if (count > 0) mask |= LUA_MASKCOUNT;
330 return mask;
331}
332
333
334/*
335** Convert a bit mask (for 'gethook') into a string mask
336*/
337static char *unmakemask (int mask, char *smask) {
338 int i = 0;
339 if (mask & LUA_MASKCALL) smask[i++] = 'c';
340 if (mask & LUA_MASKRET) smask[i++] = 'r';
341 if (mask & LUA_MASKLINE) smask[i++] = 'l';
342 smask[i] = '\0';
343 return smask;
344}
345
346
347static int db_sethook (lua_State *L) {
348 int arg, mask, count;
349 lua_Hook func;
350 lua_State *L1 = getthread(L, &arg);
351 if (lua_isnoneornil(L, arg+1)) { /* no hook? */
352 lua_settop(L, arg+1);
353 func = NULL; mask = 0; count = 0; /* turn off hooks */
354 }
355 else {
356 const char *smask = luaL_checkstring(L, arg+2);
357 luaL_checktype(L, arg+1, LUA_TFUNCTION);
358 count = (int)luaL_optinteger(L, arg + 3, 0);
359 func = hookf; mask = makemask(smask, count);
360 }
361 if (lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY) == LUA_TNIL) {
362 lua_createtable(L, 0, 2); /* create a hook table */
363 lua_pushvalue(L, -1);
364 lua_rawsetp(L, LUA_REGISTRYINDEX, &HOOKKEY); /* set it in position */
365 lua_pushstring(L, "k");
366 lua_setfield(L, -2, "__mode"); /** hooktable.__mode = "k" */
367 lua_pushvalue(L, -1);
368 lua_setmetatable(L, -2); /* setmetatable(hooktable) = hooktable */
369 }
370 checkstack(L, L1, 1);
371 lua_pushthread(L1); lua_xmove(L1, L, 1); /* key (thread) */
372 lua_pushvalue(L, arg + 1); /* value (hook function) */
373 lua_rawset(L, -3); /* hooktable[L1] = new Lua hook */
374 lua_sethook(L1, func, mask, count);
375 return 0;
376}
377
378
379static int db_gethook (lua_State *L) {
380 int arg;
381 lua_State *L1 = getthread(L, &arg);
382 char buff[5];
383 int mask = lua_gethookmask(L1);
384 lua_Hook hook = lua_gethook(L1);
385 if (hook == NULL) /* no hook? */
386 lua_pushnil(L);
387 else if (hook != hookf) /* external hook? */
388 lua_pushliteral(L, "external hook");
389 else { /* hook table must exist */
390 lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY);
391 checkstack(L, L1, 1);
392 lua_pushthread(L1); lua_xmove(L1, L, 1);
393 lua_rawget(L, -2); /* 1st result = hooktable[L1] */
394 lua_remove(L, -2); /* remove hook table */
395 }
396 lua_pushstring(L, unmakemask(mask, buff)); /* 2nd result = mask */
397 lua_pushinteger(L, lua_gethookcount(L1)); /* 3rd result = count */
398 return 3;
399}
400
401
402static int db_debug (lua_State *L) {
403 for (;;) {
404 char buffer[250];
405 lua_writestringerror("%s", "lua_debug> ");
406 if (fgets(buffer, sizeof(buffer), stdin) == 0 ||
407 strcmp(buffer, "cont\n") == 0)
408 return 0;
409 if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") ||
410 lua_pcall(L, 0, 0, 0))
411 lua_writestringerror("%s\n", lua_tostring(L, -1));
412 lua_settop(L, 0); /* remove eventual returns */
413 }
414}
415
416
417static int db_traceback (lua_State *L) {
418 int arg;
419 lua_State *L1 = getthread(L, &arg);
420 const char *msg = lua_tostring(L, arg + 1);
421 if (msg == NULL && !lua_isnoneornil(L, arg + 1)) /* non-string 'msg'? */
422 lua_pushvalue(L, arg + 1); /* return it untouched */
423 else {
424 int level = (int)luaL_optinteger(L, arg + 2, (L == L1) ? 1 : 0);
425 luaL_traceback(L, L1, msg, level);
426 }
427 return 1;
428}
429
430
431static const luaL_Reg dblib[] = {
432 {"debug", db_debug},
433 {"getuservalue", db_getuservalue},
434 {"gethook", db_gethook},
435 {"getinfo", db_getinfo},
436 {"getlocal", db_getlocal},
437 {"getregistry", db_getregistry},
438 {"getmetatable", db_getmetatable},
439 {"getupvalue", db_getupvalue},
440 {"upvaluejoin", db_upvaluejoin},
441 {"upvalueid", db_upvalueid},
442 {"setuservalue", db_setuservalue},
443 {"sethook", db_sethook},
444 {"setlocal", db_setlocal},
445 {"setmetatable", db_setmetatable},
446 {"setupvalue", db_setupvalue},
447 {"traceback", db_traceback},
448 {NULL, NULL}
449};
450
451
452LUAMOD_API int luaopen_debug (lua_State *L) {
453 luaL_newlib(L, dblib);
454 return 1;
455}
456
457