/* ** $Id: ldebug.c,v 2.121.1.2 2017/07/10 17:21:50 roberto Exp $ ** Debug Interface ** See Copyright Notice in lua.h */ #define ldebug_c #define LUA_CORE #include "lprefix.h" #include #include #include #include "lua.h" #include "lapi.h" #include "lcode.h" #include "ldebug.h" #include "ldo.h" #include "lfunc.h" #include "lobject.h" #include "lopcodes.h" #include "lstate.h" #include "lstring.h" #include "ltable.h" #include "ltm.h" #include "lvm.h" #define noLuaClosure(f) ((f) == NULL || (f)->c.tt == LUA_TCCL) /* Active Lua function (given call info) */ #define ci_func(ci) (clLvalue((ci)->func)) static const char *funcnamefromcode (lua_State *L, CallInfo *ci, const char **name); static int currentpc (CallInfo *ci) { lua_assert(isLua(ci)); return pcRel(ci->u.l.savedpc, ci_func(ci)->p); } static int currentline (CallInfo *ci) { return getfuncline(ci_func(ci)->p, currentpc(ci)); } /* ** If function yielded, its 'func' can be in the 'extra' field. The ** next function restores 'func' to its correct value for debugging ** purposes. (It exchanges 'func' and 'extra'; so, when called again, ** after debugging, it also "re-restores" ** 'func' to its altered value. */ static void swapextra (lua_State *L) { if (L->status == LUA_YIELD) { CallInfo *ci = L->ci; /* get function that yielded */ StkId temp = ci->func; /* exchange its 'func' and 'extra' values */ ci->func = restorestack(L, ci->extra); ci->extra = savestack(L, temp); } } /* ** This function can be called asynchronously (e.g. during a signal). ** Fields 'oldpc', 'basehookcount', and 'hookcount' (set by ** 'resethookcount') are for debug only, and it is no problem if they ** get arbitrary values (causes at most one wrong hook call). 'hookmask' ** is an atomic value. We assume that pointers are atomic too (e.g., gcc ** ensures that for all platforms where it runs). Moreover, 'hook' is ** always checked before being called (see 'luaD_hook'). */ LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) { if (func == NULL || mask == 0) { /* turn off hooks? */ mask = 0; func = NULL; } if (isLua(L->ci)) L->oldpc = L->ci->u.l.savedpc; L->hook = func; L->basehookcount = count; resethookcount(L); L->hookmask = cast_byte(mask); } LUA_API lua_Hook lua_gethook (lua_State *L) { return L->hook; } LUA_API int lua_gethookmask (lua_State *L) { return L->hookmask; } LUA_API int lua_gethookcount (lua_State *L) { return L->basehookcount; } LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) { int status; CallInfo *ci; if (level < 0) return 0; /* invalid (negative) level */ lua_lock(L); for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous) level--; if (level == 0 && ci != &L->base_ci) { /* level found? */ status = 1; ar->i_ci = ci; } else status = 0; /* no such level */ lua_unlock(L); return status; } static const char *upvalname (Proto *p, int uv) { TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name); if (s == NULL) return "?"; else return getstr(s); } static const char *findvararg (CallInfo *ci, int n, StkId *pos) { int nparams = clLvalue(ci->func)->p->numparams; if (n >= cast_int(ci->u.l.base - ci->func) - nparams) return NULL; /* no such vararg */ else { *pos = ci->func + nparams + n; return "(*vararg)"; /* generic name for any vararg */ } } static const char *findlocal (lua_State *L, CallInfo *ci, int n, StkId *pos) { const char *name = NULL; StkId base; if (isLua(ci)) { if (n < 0) /* access to vararg values? */ return findvararg(ci, -n, pos); else { base = ci->u.l.base; name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci)); } } else base = ci->func + 1; if (name == NULL) { /* no 'standard' name? */ StkId limit = (ci == L->ci) ? L->top : ci->next->func; if (limit - base >= n && n > 0) /* is 'n' inside 'ci' stack? */ name = "(*temporary)"; /* generic name for any valid slot */ else return NULL; /* no name */ } *pos = base + (n - 1); return name; } LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) { const char *name; lua_lock(L); swapextra(L); if (ar == NULL) { /* information about non-active function? */ if (!isLfunction(L->top - 1)) /* not a Lua function? */ name = NULL; else /* consider live variables at function start (parameters) */ name = luaF_getlocalname(clLvalue(L->top - 1)->p, n, 0); } else { /* active function; get information through 'ar' */ StkId pos = NULL; /* to avoid warnings */ name = findlocal(L, ar->i_ci, n, &pos); if (name) { setobj2s(L, L->top, pos); api_incr_top(L); } } swapextra(L); lua_unlock(L); return name; } LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) { StkId pos = NULL; /* to avoid warnings */ const char *name; lua_lock(L); swapextra(L); name = findlocal(L, ar->i_ci, n, &pos); if (name) { setobjs2s(L, pos, L->top - 1); L->top--; /* pop value */ } swapextra(L); lua_unlock(L); return name; } static void funcinfo (lua_Debug *ar, Closure *cl) { if (noLuaClosure(cl)) { ar->source = "=[C]"; ar->linedefined = -1; ar->lastlinedefined = -1; ar->what = "C"; } else { Proto *p = cl->l.p; ar->source = p->source ? getstr(p->source) : "=?"; ar->linedefined = p->linedefined; ar->lastlinedefined = p->lastlinedefined; ar->what = (ar->linedefined == 0) ? "main" : "Lua"; } luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE); } static void collectvalidlines (lua_State *L, Closure *f) { if (noLuaClosure(f)) { setnilvalue(L->top); api_incr_top(L); } else { int i; TValue v; int *lineinfo = f->l.p->lineinfo; Table *t = luaH_new(L); /* new table to store active lines */ sethvalue(L, L->top, t); /* push it on stack */ api_incr_top(L); setbvalue(&v, 1); /* boolean 'true' to be the value of all indices */ for (i = 0; i < f->l.p->sizelineinfo; i++) /* for all lines with code */ luaH_setint(L, t, lineinfo[i], &v); /* table[line] = true */ } } static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) { if (ci == NULL) /* no 'ci'? */ return NULL; /* no info */ else if (ci->callstatus & CIST_FIN) { /* is this a finalizer? */ *name = "__gc"; return "metamethod"; /* report it as such */ } /* calling function is a known Lua function? */ else if (!(ci->callstatus & CIST_TAIL) && isLua(ci->previous)) return funcnamefromcode(L, ci->previous, name); else return NULL; /* no way to find a name */ } static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar, Closure *f, CallInfo *ci) { int status = 1; for (; *what; what++) { switch (*what) { case 'S': { funcinfo(ar, f); break; } case 'l': { ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1; break; } case 'u': { ar->nups = (f == NULL) ? 0 : f->c.nupvalues; if (noLuaClosure(f)) { ar->isvararg = 1; ar->nparams = 0; } else { ar->isvararg = f->l.p->is_vararg; ar->nparams = f->l.p->numparams; } break; } case 't': { ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0; break; } case 'n': { ar->namewhat = getfuncname(L, ci, &ar->name); if (ar->namewhat == NULL) { ar->namewhat = ""; /* not found */ ar->name = NULL; } break; } case 'L': case 'f': /* handled by lua_getinfo */ break; default: status = 0; /* invalid option */ } } return status; } LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) { int status; Closure *cl; CallInfo *ci; StkId func; lua_lock(L); swapextra(L); if (*what == '>') { ci = NULL; func = L->top - 1; api_check(L, ttisfunction(func), "function expected"); what++; /* skip the '>' */ L->top--; /* pop function */ } else { ci = ar->i_ci; func = ci->func; lua_assert(ttisfunction(ci->func)); } cl = ttisclosure(func) ? clvalue(func) : NULL; status = auxgetinfo(L, what, ar, cl, ci); if (strchr(what, 'f')) { setobjs2s(L, L->top, func); api_incr_top(L); } swapextra(L); /* correct before option 'L', which can raise a mem. error */ if (strchr(what, 'L')) collectvalidlines(L, cl); lua_unlock(L); return status; } /* ** {====================================================== ** Symbolic Execution ** ======================================================= */ static const char *getobjname (Proto *p, int lastpc, int reg, const char **name); /* ** find a "name" for the RK value 'c' */ static void kname (Proto *p, int pc, int c, const char **name) { if (ISK(c)) { /* is 'c' a constant? */ TValue *kvalue = &p->k[INDEXK(c)]; if (ttisstring(kvalue)) { /* literal constant? */ *name = svalue(kvalue); /* it is its own name */ return; } /* else no reasonable name found */ } else { /* 'c' is a register */ const char *what = getobjname(p, pc, c, name); /* search for 'c' */ if (what && *what == 'c') { /* found a constant name? */ return; /* 'name' already filled */ } /* else no reasonable name found */ } *name = "?"; /* no reasonable name found */ } static int filterpc (int pc, int jmptarget) { if (pc < jmptarget) /* is code conditional (inside a jump)? */ return -1; /* cannot know who sets that register */ else return pc; /* current position sets that register */ } /* ** try to find last instruction before 'lastpc' that modified register 'reg' */ static int findsetreg (Proto *p, int lastpc, int reg) { int pc; int setreg = -1; /* keep last instruction that changed 'reg' */ int jmptarget = 0; /* any code before this address is conditional */ for (pc = 0; pc < lastpc; pc++) { Instruction i = p->code[pc]; OpCode op = GET_OPCODE(i); int a = GETARG_A(i); switch (op) { case OP_LOADNIL: { int b = GETARG_B(i); if (a <= reg && reg <= a + b) /* set registers from 'a' to 'a+b' */ setreg = filterpc(pc, jmptarget); break; } case OP_TFORCALL: { if (reg >= a + 2) /* affect all regs above its base */ setreg = filterpc(pc, jmptarget); break; } case OP_CALL: case OP_TAILCALL: { if (reg >= a) /* affect all registers above base */ setreg = filterpc(pc, jmptarget); break; } case OP_JMP: { int b = GETARG_sBx(i); int dest = pc + 1 + b; /* jump is forward and do not skip 'lastpc'? */ if (pc < dest && dest <= lastpc) { if (dest > jmptarget) jmptarget = dest; /* update 'jmptarget' */ } break; } default: if (testAMode(op) && reg == a) /* any instruction that set A */ setreg = filterpc(pc, jmptarget); break; } } return setreg; } static const char *getobjname (Proto *p, int lastpc, int reg, const char **name) { int pc; *name = luaF_getlocalname(p, reg + 1, lastpc); if (*name) /* is a local? */ return "local"; /* else try symbolic execution */ pc = findsetreg(p, lastpc, reg); if (pc != -1) { /* could find instruction? */ Instruction i = p->code[pc]; OpCode op = GET_OPCODE(i); switch (op) { case OP_MOVE: { int b = GETARG_B(i); /* move from 'b' to 'a' */ if (b < GETARG_A(i)) return getobjname(p, pc, b, name); /* get name for 'b' */ break; } case OP_GETTABUP: case OP_GETTABLE: { int k = GETARG_C(i); /* key index */ int t = GETARG_B(i); /* table index */ const char *vn = (op == OP_GETTABLE) /* name of indexed variable */ ? luaF_getlocalname(p, t + 1, pc) : upvalname(p, t); kname(p, pc, k, name); return (vn && strcmp(vn, LUA_ENV) == 0) ? "global" : "field"; } case OP_GETUPVAL: { *name = upvalname(p, GETARG_B(i)); return "upvalue"; } case OP_LOADK: case OP_LOADKX: { int b = (op == OP_LOADK) ? GETARG_Bx(i) : GETARG_Ax(p->code[pc + 1]); if (ttisstring(&p->k[b])) { *name = svalue(&p->k[b]); return "constant"; } break; } case OP_SELF: { int k = GETARG_C(i); /* key index */ kname(p, pc, k, name); return "method"; } default: break; /* go through to return NULL */ } } return NULL; /* could not find reasonable name */ } /* ** Try to find a name for a function based on the code that called it. ** (Only works when function was called by a Lua function.) ** Returns what the name is (e.g., "for iterator", "method", ** "metamethod") and sets '*name' to point to the name. */ static const char *funcnamefromcode (lua_State *L, CallInfo *ci, const char **name) { TMS tm = (TMS)0; /* (initial value avoids warnings) */ Proto *p = ci_func(ci)->p; /* calling function */ int pc = currentpc(ci); /* calling instruction index */ Instruction i = p->code[pc]; /* calling instruction */ if (ci->callstatus & CIST_HOOKED) { /* was it called inside a hook? */ *name = "?"; return "hook"; } switch (GET_OPCODE(i)) { case OP_CALL: case OP_TAILCALL: return getobjname(p, pc, GETARG_A(i), name); /* get function name */ case OP_TFORCALL: { /* for iterator */ *name = "for iterator"; return "for iterator"; } /* other instructions can do calls through metamethods */ case OP_SELF: case OP_GETTABUP: case OP_GETTABLE: tm = TM_INDEX; break; case OP_SETTABUP: case OP_SETTABLE: tm = TM_NEWINDEX; break; case OP_ADD: case OP_SUB: case OP_MUL: case OP_MOD: case OP_POW: case OP_DIV: case OP_IDIV: case OP_BAND: case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR: { int offset = cast_int(GET_OPCODE(i)) - cast_int(OP_ADD); /* ORDER OP */ tm = cast(TMS, offset + cast_int(TM_ADD)); /* ORDER TM */ break; } case OP_UNM: tm = TM_UNM; break; case OP_BNOT: tm = TM_BNOT; break; case OP_LEN: tm = TM_LEN; break; case OP_CONCAT: tm = TM_CONCAT; break; case OP_EQ: tm = TM_EQ; break; case OP_LT: tm = TM_LT; break; case OP_LE: tm = TM_LE; break; default: return NULL; /* cannot find a reasonable name */ } *name = getstr(G(L)->tmname[tm]); return "metamethod"; } /* }====================================================== */ /* ** The subtraction of two potentially unrelated pointers is ** not ISO C, but it should not crash a program; the subsequent ** checks are ISO C and ensure a correct result. */ static int isinstack (CallInfo *ci, const TValue *o) { ptrdiff_t i = o - ci->u.l.base; return (0 <= i && i < (ci->top - ci->u.l.base) && ci->u.l.base + i == o); } /* ** Checks whether value 'o' came from an upvalue. (That can only happen ** with instructions OP_GETTABUP/OP_SETTABUP, which operate directly on ** upvalues.) */ static const char *getupvalname (CallInfo *ci, const TValue *o, const char **name) { LClosure *c = ci_func(ci); int i; for (i = 0; i < c->nupvalues; i++) { if (c->upvals[i]->v == o) { *name = upvalname(c->p, i); return "upvalue"; } } return NULL; } static const char *varinfo (lua_State *L, const TValue *o) { const char *name = NULL; /* to avoid warnings */ CallInfo *ci = L->ci; const char *kind = NULL; if (isLua(ci)) { kind = getupvalname(ci, o, &name); /* check whether 'o' is an upvalue */ if (!kind && isinstack(ci, o)) /* no? try a register */ kind = getobjname(ci_func(ci)->p, currentpc(ci), cast_int(o - ci->u.l.base), &name); } return (kind) ? luaO_pushfstring(L, " (%s '%s')", kind, name) : ""; } l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) { const char *t = luaT_objtypename(L, o); luaG_runerror(L, "attempt to %s a %s value%s", op, t, varinfo(L, o)); } l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) { if (ttisstring(p1) || cvt2str(p1)) p1 = p2; luaG_typeerror(L, p1, "concatenate"); } l_noret luaG_opinterror (lua_State *L, const TValue *p1, const TValue *p2, const char *msg) { lua_Number temp; if (!tonumber(p1, &temp)) /* first operand is wrong? */ p2 = p1; /* now second is wrong */ luaG_typeerror(L, p2, msg); } /* ** Error when both values are convertible to numbers, but not to integers */ l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) { lua_Integer temp; if (!tointeger(p1, &temp)) p2 = p1; luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2)); } l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) { const char *t1 = luaT_objtypename(L, p1); const char *t2 = luaT_objtypename(L, p2); if (strcmp(t1, t2) == 0) luaG_runerror(L, "attempt to compare two %s values", t1); else luaG_runerror(L, "attempt to compare %s with %s", t1, t2); } /* add src:line information to 'msg' */ const char *luaG_addinfo (lua_State *L, const char *msg, TString *src, int line) { char buff[LUA_IDSIZE]; if (src) luaO_chunkid(buff, getstr(src), LUA_IDSIZE); else { /* no source available; use "?" instead */ buff[0] = '?'; buff[1] = '\0'; } return luaO_pushfstring(L, "%s:%d: %s", buff, line, msg); } l_noret luaG_errormsg (lua_State *L) { if (L->errfunc != 0) { /* is there an error handling function? */ StkId errfunc = restorestack(L, L->errfunc); setobjs2s(L, L->top, L->top - 1); /* move argument */ setobjs2s(L, L->top - 1, errfunc); /* push function */ L->top++; /* assume EXTRA_STACK */ luaD_callnoyield(L, L->top - 2, 1); /* call it */ } luaD_throw(L, LUA_ERRRUN); } l_noret luaG_runerror (lua_State *L, const char *fmt, ...) { CallInfo *ci = L->ci; const char *msg; va_list argp; luaC_checkGC(L); /* error message uses memory */ va_start(argp, fmt); msg = luaO_pushvfstring(L, fmt, argp); /* format message */ va_end(argp); if (isLua(ci)) /* if Lua function, add source:line information */ luaG_addinfo(L, msg, ci_func(ci)->p->source, currentline(ci)); luaG_errormsg(L); } void luaG_traceexec (lua_State *L) { CallInfo *ci = L->ci; lu_byte mask = L->hookmask; int counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT)); if (counthook) resethookcount(L); /* reset count */ else if (!(mask & LUA_MASKLINE)) return; /* no line hook and count != 0; nothing to be done */ if (ci->callstatus & CIST_HOOKYIELD) { /* called hook last time? */ ci->callstatus &= ~CIST_HOOKYIELD; /* erase mark */ return; /* do not call hook again (VM yielded, so it did not move) */ } if (counthook) luaD_hook(L, LUA_HOOKCOUNT, -1); /* call count hook */ if (mask & LUA_MASKLINE) { Proto *p = ci_func(ci)->p; int npc = pcRel(ci->u.l.savedpc, p); int newline = getfuncline(p, npc); if (npc == 0 || /* call linehook when enter a new function, */ ci->u.l.savedpc <= L->oldpc || /* when jump back (loop), or when */ newline != getfuncline(p, pcRel(L->oldpc, p))) /* enter a new line */ luaD_hook(L, LUA_HOOKLINE, newline); /* call line hook */ } L->oldpc = ci->u.l.savedpc; if (L->status == LUA_YIELD) { /* did hook yield? */ if (counthook) L->hookcount = 1; /* undo decrement to zero */ ci->u.l.savedpc--; /* undo increment (resume will increment it again) */ ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */ ci->func = L->top - 1; /* protect stack below results */ luaD_throw(L, LUA_YIELD); } }