xref: /minix3/external/mit/lua/dist/src/ldblib.c (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
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