client/deps/liblua/ldebug.c

   1 /*
   2 ** $Id: ldebug.c,v 2.90 2012/08/16 17:34:28 roberto Exp $
   3 ** Debug Interface
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #include <stdarg.h>
   9 #include <stddef.h>
  10 #include <string.h>
  11
  12
  13 #define ldebug_c
  14 #define LUA_CORE
  15
  16 #include "lua.h"
  17
  18 #include "lapi.h"
  19 #include "lcode.h"
  20 #include "ldebug.h"
  21 #include "ldo.h"
  22 #include "lfunc.h"
  23 #include "lobject.h"
  24 #include "lopcodes.h"
  25 #include "lstate.h"
  26 #include "lstring.h"
  27 #include "ltable.h"
  28 #include "ltm.h"
  29 #include "lvm.h"
  30
  31
  32
  33 #define noLuaClosure(f) ((f) == NULL || (f)->c.tt == LUA_TCCL)
  34
  35
  36 static const char *getfuncname(lua_State *L, CallInfo *ci, const char **name);
  37
  38
  39 static int currentpc(CallInfo *ci) {
  40     lua_assert(isLua(ci));
  41     return pcRel(ci->u.l.savedpc, ci_func(ci)->p);
  42 }
  43
  44
  45 static int currentline(CallInfo *ci) {
  46     return getfuncline(ci_func(ci)->p, currentpc(ci));
  47 }
  48
  49
  50 /*
  51 ** this function can be called asynchronous (e.g. during a signal)
  52 */
  53 LUA_API int lua_sethook(lua_State *L, lua_Hook func, int mask, int count) {
  54     if (func == NULL || mask == 0) {  /* turn off hooks? */
  55         mask = 0;
  56         func = NULL;
  57     }
  58     if (isLua(L->ci))
  59         L->oldpc = L->ci->u.l.savedpc;
  60     L->hook = func;
  61     L->basehookcount = count;
  62     resethookcount(L);
  63     L->hookmask = cast_byte(mask);
  64     return 1;
  65 }
  66
  67
  68 LUA_API lua_Hook lua_gethook(lua_State *L) {
  69     return L->hook;
  70 }
  71
  72
  73 LUA_API int lua_gethookmask(lua_State *L) {
  74     return L->hookmask;
  75 }
  76
  77
  78 LUA_API int lua_gethookcount(lua_State *L) {
  79     return L->basehookcount;
  80 }
  81
  82
  83 LUA_API int lua_getstack(lua_State *L, int level, lua_Debug *ar) {
  84     int status;
  85     CallInfo *ci;
  86     if (level < 0) return 0;  /* invalid (negative) level */
  87     lua_lock(L);
  88     for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous)
  89         level--;
  90     if (level == 0 && ci != &L->base_ci) {  /* level found? */
  91         status = 1;
  92         ar->i_ci = ci;
  93     } else status = 0; /* no such level */
  94     lua_unlock(L);
  95     return status;
  96 }
  97
  98
  99 static const char *upvalname(Proto *p, int uv) {
 100     TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name);
 101     if (s == NULL) return "?";
 102     else return getstr(s);
 103 }
 104
 105
 106 static const char *findvararg(CallInfo *ci, int n, StkId *pos) {
 107     int nparams = clLvalue(ci->func)->p->numparams;
 108     if (n >= ci->u.l.base - ci->func - nparams)
 109         return NULL;  /* no such vararg */
 110     else {
 111         *pos = ci->func + nparams + n;
 112         return "(*vararg)";  /* generic name for any vararg */
 113     }
 114 }
 115
 116
 117 static const char *findlocal(lua_State *L, CallInfo *ci, int n,
 118                              StkId *pos) {
 119     const char *name = NULL;
 120     StkId base;
 121     if (isLua(ci)) {
 122         if (n < 0)  /* access to vararg values? */
 123             return findvararg(ci, -n, pos);
 124         else {
 125             base = ci->u.l.base;
 126             name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
 127         }
 128     } else
 129         base = ci->func + 1;
 130     if (name == NULL) {  /* no 'standard' name? */
 131         StkId limit = (ci == L->ci) ? L->top : ci->next->func;
 132         if (limit - base >= n && n > 0)  /* is 'n' inside 'ci' stack? */
 133             name = "(*temporary)";  /* generic name for any valid slot */
 134         else
 135             return NULL;  /* no name */
 136     }
 137     *pos = base + (n - 1);
 138     return name;
 139 }
 140
 141
 142 LUA_API const char *lua_getlocal(lua_State *L, const lua_Debug *ar, int n) {
 143     const char *name;
 144     lua_lock(L);
 145     if (ar == NULL) {  /* information about non-active function? */
 146         if (!isLfunction(L->top - 1))  /* not a Lua function? */
 147             name = NULL;
 148         else  /* consider live variables at function start (parameters) */
 149             name = luaF_getlocalname(clLvalue(L->top - 1)->p, n, 0);
 150     } else { /* active function; get information through 'ar' */
 151         StkId pos = 0;  /* to avoid warnings */
 152         name = findlocal(L, ar->i_ci, n, &pos);
 153         if (name) {
 154             setobj2s(L, L->top, pos);
 155             api_incr_top(L);
 156         }
 157     }
 158     lua_unlock(L);
 159     return name;
 160 }
 161
 162
 163 LUA_API const char *lua_setlocal(lua_State *L, const lua_Debug *ar, int n) {
 164     StkId pos = 0;  /* to avoid warnings */
 165     const char *name = findlocal(L, ar->i_ci, n, &pos);
 166     lua_lock(L);
 167     if (name)
 168         setobjs2s(L, pos, L->top - 1);
 169     L->top--;  /* pop value */
 170     lua_unlock(L);
 171     return name;
 172 }
 173
 174
 175 static void funcinfo(lua_Debug *ar, Closure *cl) {
 176     if (noLuaClosure(cl)) {
 177         ar->source = "=[C]";
 178         ar->linedefined = -1;
 179         ar->lastlinedefined = -1;
 180         ar->what = "C";
 181     } else {
 182         Proto *p = cl->l.p;
 183         ar->source = p->source ? getstr(p->source) : "=?";
 184         ar->linedefined = p->linedefined;
 185         ar->lastlinedefined = p->lastlinedefined;
 186         ar->what = (ar->linedefined == 0) ? "main" : "Lua";
 187     }
 188     luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
 189 }
 190
 191
 192 static void collectvalidlines(lua_State *L, Closure *f) {
 193     if (noLuaClosure(f)) {
 194         setnilvalue(L->top);
 195         api_incr_top(L);
 196     } else {
 197         int i;
 198         TValue v;
 199         int *lineinfo = f->l.p->lineinfo;
 200         Table *t = luaH_new(L);  /* new table to store active lines */
 201         sethvalue(L, L->top, t);  /* push it on stack */
 202         api_incr_top(L);
 203         setbvalue(&v, 1);  /* boolean 'true' to be the value of all indices */
 204         for (i = 0; i < f->l.p->sizelineinfo; i++)  /* for all lines with code */
 205             luaH_setint(L, t, lineinfo[i], &v);  /* table[line] = true */
 206     }
 207 }
 208
 209
 210 static int auxgetinfo(lua_State *L, const char *what, lua_Debug *ar,
 211                       Closure *f, CallInfo *ci) {
 212     int status = 1;
 213     for (; *what; what++) {
 214         switch (*what) {
 215             case 'S': {
 216                 funcinfo(ar, f);
 217                 break;
 218             }
 219             case 'l': {
 220                 ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1;
 221                 break;
 222             }
 223             case 'u': {
 224                 ar->nups = (f == NULL) ? 0 : f->c.nupvalues;
 225                 if (noLuaClosure(f)) {
 226                     ar->isvararg = 1;
 227                     ar->nparams = 0;
 228                 } else {
 229                     ar->isvararg = f->l.p->is_vararg;
 230                     ar->nparams = f->l.p->numparams;
 231                 }
 232                 break;
 233             }
 234             case 't': {
 235                 ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0;
 236                 break;
 237             }
 238             case 'n': {
 239                 /* calling function is a known Lua function? */
 240                 if (ci && !(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
 241                     ar->namewhat = getfuncname(L, ci->previous, &ar->name);
 242                 else
 243                     ar->namewhat = NULL;
 244                 if (ar->namewhat == NULL) {
 245                     ar->namewhat = "";  /* not found */
 246                     ar->name = NULL;
 247                 }
 248                 break;
 249             }
 250             case 'L':
 251             case 'f':  /* handled by lua_getinfo */
 252                 break;
 253             default:
 254                 status = 0;  /* invalid option */
 255         }
 256     }
 257     return status;
 258 }
 259
 260
 261 LUA_API int lua_getinfo(lua_State *L, const char *what, lua_Debug *ar) {
 262     int status;
 263     Closure *cl;
 264     CallInfo *ci;
 265     StkId func;
 266     lua_lock(L);
 267     if (*what == '>') {
 268         ci = NULL;
 269         func = L->top - 1;
 270         api_check(L, ttisfunction(func), "function expected");
 271         what++;  /* skip the '>' */
 272         L->top--;  /* pop function */
 273     } else {
 274         ci = ar->i_ci;
 275         func = ci->func;
 276         lua_assert(ttisfunction(ci->func));
 277     }
 278     cl = ttisclosure(func) ? clvalue(func) : NULL;
 279     status = auxgetinfo(L, what, ar, cl, ci);
 280     if (strchr(what, 'f')) {
 281         setobjs2s(L, L->top, func);
 282         api_incr_top(L);
 283     }
 284     if (strchr(what, 'L'))
 285         collectvalidlines(L, cl);
 286     lua_unlock(L);
 287     return status;
 288 }
 289
 290
 291 /*
 292 ** {======================================================
 293 ** Symbolic Execution
 294 ** =======================================================
 295 */
 296
 297 static const char *getobjname(Proto *p, int lastpc, int reg,
 298                               const char **name);
 299
 300
 301 /*
 302 ** find a "name" for the RK value 'c'
 303 */
 304 static void kname(Proto *p, int pc, int c, const char **name) {
 305     if (ISK(c)) {  /* is 'c' a constant? */
 306         TValue *kvalue = &p->k[INDEXK(c)];
 307         if (ttisstring(kvalue)) {  /* literal constant? */
 308             *name = svalue(kvalue);  /* it is its own name */
 309             return;
 310         }
 311         /* else no reasonable name found */
 312     } else { /* 'c' is a register */
 313         const char *what = getobjname(p, pc, c, name); /* search for 'c' */
 314         if (what && *what == 'c') {  /* found a constant name? */
 315             return;  /* 'name' already filled */
 316         }
 317         /* else no reasonable name found */
 318     }
 319     *name = "?";  /* no reasonable name found */
 320 }
 321
 322
 323 /*
 324 ** try to find last instruction before 'lastpc' that modified register 'reg'
 325 */
 326 static int findsetreg(Proto *p, int lastpc, int reg) {
 327     int pc;
 328     int setreg = -1;  /* keep last instruction that changed 'reg' */
 329     for (pc = 0; pc < lastpc; pc++) {
 330         Instruction i = p->code[pc];
 331         OpCode op = GET_OPCODE(i);
 332         int a = GETARG_A(i);
 333         switch (op) {
 334             case OP_LOADNIL: {
 335                 int b = GETARG_B(i);
 336                 if (a <= reg && reg <= a + b)  /* set registers from 'a' to 'a+b' */
 337                     setreg = pc;
 338                 break;
 339             }
 340             case OP_TFORCALL: {
 341                 if (reg >= a + 2) setreg = pc;  /* affect all regs above its base */
 342                 break;
 343             }
 344             case OP_CALL:
 345             case OP_TAILCALL: {
 346                 if (reg >= a) setreg = pc;  /* affect all registers above base */
 347                 break;
 348             }
 349             case OP_JMP: {
 350                 int b = GETARG_sBx(i);
 351                 int dest = pc + 1 + b;
 352                 /* jump is forward and do not skip `lastpc'? */
 353                 if (pc < dest && dest <= lastpc)
 354                     pc += b;  /* do the jump */
 355                 break;
 356             }
 357             case OP_TEST: {
 358                 if (reg == a) setreg = pc;  /* jumped code can change 'a' */
 359                 break;
 360             }
 361             default:
 362                 if (testAMode(op) && reg == a)  /* any instruction that set A */
 363                     setreg = pc;
 364                 break;
 365         }
 366     }
 367     return setreg;
 368 }
 369
 370
 371 static const char *getobjname(Proto *p, int lastpc, int reg,
 372                               const char **name) {
 373     int pc;
 374     *name = luaF_getlocalname(p, reg + 1, lastpc);
 375     if (*name)  /* is a local? */
 376         return "local";
 377     /* else try symbolic execution */
 378     pc = findsetreg(p, lastpc, reg);
 379     if (pc != -1) {  /* could find instruction? */
 380         Instruction i = p->code[pc];
 381         OpCode op = GET_OPCODE(i);
 382         switch (op) {
 383             case OP_MOVE: {
 384                 int b = GETARG_B(i);  /* move from 'b' to 'a' */
 385                 if (b < GETARG_A(i))
 386                     return getobjname(p, pc, b, name);  /* get name for 'b' */
 387                 break;
 388             }
 389             case OP_GETTABUP:
 390             case OP_GETTABLE: {
 391                 int k = GETARG_C(i);  /* key index */
 392                 int t = GETARG_B(i);  /* table index */
 393                 const char *vn = (op == OP_GETTABLE)  /* name of indexed variable */
 394                                  ? luaF_getlocalname(p, t + 1, pc)
 395                                  : upvalname(p, t);
 396                 kname(p, pc, k, name);
 397                 return (vn && strcmp(vn, LUA_ENV) == 0) ? "global" : "field";
 398             }
 399             case OP_GETUPVAL: {
 400                 *name = upvalname(p, GETARG_B(i));
 401                 return "upvalue";
 402             }
 403             case OP_LOADK:
 404             case OP_LOADKX: {
 405                 int b = (op == OP_LOADK) ? GETARG_Bx(i)
 406                         : GETARG_Ax(p->code[pc + 1]);
 407                 if (ttisstring(&p->k[b])) {
 408                     *name = svalue(&p->k[b]);
 409                     return "constant";
 410                 }
 411                 break;
 412             }
 413             case OP_SELF: {
 414                 int k = GETARG_C(i);  /* key index */
 415                 kname(p, pc, k, name);
 416                 return "method";
 417             }
 418             default:
 419                 break;  /* go through to return NULL */
 420         }
 421     }
 422     return NULL;  /* could not find reasonable name */
 423 }
 424
 425
 426 static const char *getfuncname(lua_State *L, CallInfo *ci, const char **name) {
 427     TMS tm;
 428     Proto *p = ci_func(ci)->p;  /* calling function */
 429     int pc = currentpc(ci);  /* calling instruction index */
 430     Instruction i = p->code[pc];  /* calling instruction */
 431     switch (GET_OPCODE(i)) {
 432         case OP_CALL:
 433         case OP_TAILCALL:  /* get function name */
 434             return getobjname(p, pc, GETARG_A(i), name);
 435         case OP_TFORCALL: {  /* for iterator */
 436             *name = "for iterator";
 437             return "for iterator";
 438         }
 439         /* all other instructions can call only through metamethods */
 440         case OP_SELF:
 441         case OP_GETTABUP:
 442         case OP_GETTABLE:
 443             tm = TM_INDEX;
 444             break;
 445         case OP_SETTABUP:
 446         case OP_SETTABLE:
 447             tm = TM_NEWINDEX;
 448             break;
 449         case OP_EQ:
 450             tm = TM_EQ;
 451             break;
 452         case OP_ADD:
 453             tm = TM_ADD;
 454             break;
 455         case OP_SUB:
 456             tm = TM_SUB;
 457             break;
 458         case OP_MUL:
 459             tm = TM_MUL;
 460             break;
 461         case OP_DIV:
 462             tm = TM_DIV;
 463             break;
 464         case OP_MOD:
 465             tm = TM_MOD;
 466             break;
 467         case OP_POW:
 468             tm = TM_POW;
 469             break;
 470         case OP_UNM:
 471             tm = TM_UNM;
 472             break;
 473         case OP_LEN:
 474             tm = TM_LEN;
 475             break;
 476         case OP_LT:
 477             tm = TM_LT;
 478             break;
 479         case OP_LE:
 480             tm = TM_LE;
 481             break;
 482         case OP_CONCAT:
 483             tm = TM_CONCAT;
 484             break;
 485         default:
 486             return NULL;  /* else no useful name can be found */
 487     }
 488     *name = getstr(G(L)->tmname[tm]);
 489     return "metamethod";
 490 }
 491
 492 /* }====================================================== */
 493
 494
 495
 496 /*
 497 ** only ANSI way to check whether a pointer points to an array
 498 ** (used only for error messages, so efficiency is not a big concern)
 499 */
 500 static int isinstack(CallInfo *ci, const TValue *o) {
 501     StkId p;
 502     for (p = ci->u.l.base; p < ci->top; p++)
 503         if (o == p) return 1;
 504     return 0;
 505 }
 506
 507
 508 static const char *getupvalname(CallInfo *ci, const TValue *o,
 509                                 const char **name) {
 510     LClosure *c = ci_func(ci);
 511     int i;
 512     for (i = 0; i < c->nupvalues; i++) {
 513         if (c->upvals[i]->v == o) {
 514             *name = upvalname(c->p, i);
 515             return "upvalue";
 516         }
 517     }
 518     return NULL;
 519 }
 520
 521
 522 l_noret luaG_typeerror(lua_State *L, const TValue *o, const char *op) {
 523     CallInfo *ci = L->ci;
 524     const char *name = NULL;
 525     const char *t = objtypename(o);
 526     const char *kind = NULL;
 527     if (isLua(ci)) {
 528         kind = getupvalname(ci, o, &name);  /* check whether 'o' is an upvalue */
 529         if (!kind && isinstack(ci, o))  /* no? try a register */
 530             kind = getobjname(ci_func(ci)->p, currentpc(ci),
 531                               cast_int(o - ci->u.l.base), &name);
 532     }
 533     if (kind)
 534         luaG_runerror(L, "attempt to %s %s " LUA_QS " (a %s value)",
 535                       op, kind, name, t);
 536     else
 537         luaG_runerror(L, "attempt to %s a %s value", op, t);
 538 }
 539
 540
 541 l_noret luaG_concaterror(lua_State *L, StkId p1, StkId p2) {
 542     if (ttisstring(p1) || ttisnumber(p1)) p1 = p2;
 543     lua_assert(!ttisstring(p1) && !ttisnumber(p2));
 544     luaG_typeerror(L, p1, "concatenate");
 545 }
 546
 547
 548 l_noret luaG_aritherror(lua_State *L, const TValue *p1, const TValue *p2) {
 549     TValue temp;
 550     if (luaV_tonumber(p1, &temp) == NULL)
 551         p2 = p1;  /* first operand is wrong */
 552     luaG_typeerror(L, p2, "perform arithmetic on");
 553 }
 554
 555
 556 l_noret luaG_ordererror(lua_State *L, const TValue *p1, const TValue *p2) {
 557     const char *t1 = objtypename(p1);
 558     const char *t2 = objtypename(p2);
 559     if (t1 == t2)
 560         luaG_runerror(L, "attempt to compare two %s values", t1);
 561     else
 562         luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
 563 }
 564
 565
 566 static void addinfo(lua_State *L, const char *msg) {
 567     CallInfo *ci = L->ci;
 568     if (isLua(ci)) {  /* is Lua code? */
 569         char buff[LUA_IDSIZE];  /* add file:line information */
 570         int line = currentline(ci);
 571         TString *src = ci_func(ci)->p->source;
 572         if (src)
 573             luaO_chunkid(buff, getstr(src), LUA_IDSIZE);
 574         else {  /* no source available; use "?" instead */
 575             buff[0] = '?';
 576             buff[1] = '\0';
 577         }
 578         luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
 579     }
 580 }
 581
 582
 583 l_noret luaG_errormsg(lua_State *L) {
 584     if (L->errfunc != 0) {  /* is there an error handling function? */
 585         StkId errfunc = restorestack(L, L->errfunc);
 586         if (!ttisfunction(errfunc)) luaD_throw(L, LUA_ERRERR);
 587         setobjs2s(L, L->top, L->top - 1);  /* move argument */
 588         setobjs2s(L, L->top - 1, errfunc);  /* push function */
 589         L->top++;
 590         luaD_call(L, L->top - 2, 1, 0);  /* call it */
 591     }
 592     luaD_throw(L, LUA_ERRRUN);
 593 }
 594
 595
 596 l_noret luaG_runerror(lua_State *L, const char *fmt, ...) {
 597     va_list argp;
 598     va_start(argp, fmt);
 599     addinfo(L, luaO_pushvfstring(L, fmt, argp));
 600     va_end(argp);
 601     luaG_errormsg(L);
 602 }
 603