/* ** $Id: ldebug.c,v 2.29.1.6 2008/05/08 16:56:26 roberto Exp $ ** Debug Interface ** See Copyright Notice in lua.h */ #include <stdarg.h> #include <stddef.h> #include <string.h> #define ldebug_c #define LUA_CORE #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" static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name); static int currentpc (lua_State *L, CallInfo *ci) { if (!isLua(ci)) return -1; /* function is not a Lua function? */ if (ci == L->ci) ci->savedpc = L->savedpc; return pcRel(ci->savedpc, ci_func(ci)->l.p); } static int currentline (lua_State *L, CallInfo *ci) { int pc = currentpc(L, ci); if (pc < 0) return -1; /* only active lua functions have current-line information */ else return getline(ci_func(ci)->l.p, pc); } /* ** this function can be called asynchronous (e.g. during a signal) */ LUA_API int lua_sethook (lua_State *L, lua_Hook func, int mask, int count) { if (func == NULL || mask == 0) { /* turn off hooks? */ mask = 0; func = NULL; } L->hook = func; L->basehookcount = count; resethookcount(L); L->hookmask = cast_byte(mask); return 1; } 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; lua_lock(L); for (ci = L->ci; level > 0 && ci > L->base_ci; ci--) { level--; if (f_isLua(ci)) /* Lua function? */ level -= ci->tailcalls; /* skip lost tail calls */ } if (level == 0 && ci > L->base_ci) { /* level found? */ status = 1; ar->i_ci = cast_int(ci - L->base_ci); } else if (level < 0) { /* level is of a lost tail call? */ status = 1; ar->i_ci = 0; } else status = 0; /* no such level */ lua_unlock(L); return status; } static Proto *getluaproto (CallInfo *ci) { return (isLua(ci) ? ci_func(ci)->l.p : NULL); } static const char *findlocal (lua_State *L, CallInfo *ci, int n) { const char *name; Proto *fp = getluaproto(ci); if (fp && (name = luaF_getlocalname(fp, n, currentpc(L, ci))) != NULL) return name; /* is a local variable in a Lua function */ else { StkId limit = (ci == L->ci) ? L->top : (ci+1)->func; if (limit - ci->base >= n && n > 0) /* is 'n' inside 'ci' stack? */ return "(*temporary)"; else return NULL; } } LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) { CallInfo *ci = L->base_ci + ar->i_ci; const char *name = findlocal(L, ci, n); lua_lock(L); if (name) luaA_pushobject(L, ci->base + (n - 1)); lua_unlock(L); return name; } LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) { CallInfo *ci = L->base_ci + ar->i_ci; const char *name = findlocal(L, ci, n); lua_lock(L); if (name) setobjs2s(L, ci->base + (n - 1), L->top - 1); L->top--; /* pop value */ lua_unlock(L); return name; } static void funcinfo (lua_Debug *ar, Closure *cl) { if (cl->c.isC) { ar->source = "=[C]"; ar->linedefined = -1; ar->lastlinedefined = -1; ar->what = "C"; } else { ar->source = getstr(cl->l.p->source); ar->linedefined = cl->l.p->linedefined; ar->lastlinedefined = cl->l.p->lastlinedefined; ar->what = (ar->linedefined == 0) ? "main" : "Lua"; } luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE); } static void info_tailcall (lua_Debug *ar) { ar->name = ar->namewhat = ""; ar->what = "tail"; ar->lastlinedefined = ar->linedefined = ar->currentline = -1; ar->source = "=(tail call)"; luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE); ar->nups = 0; } static void collectvalidlines (lua_State *L, Closure *f) { if (f == NULL || f->c.isC) { setnilvalue(L->top); } else { Table *t = luaH_new(L, 0, 0); int *lineinfo = f->l.p->lineinfo; int i; for (i=0; i<f->l.p->sizelineinfo; i++) setbvalue(luaH_setnum(L, t, lineinfo[i]), 1); sethvalue(L, L->top, t); } incr_top(L); } static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar, Closure *f, CallInfo *ci) { int status = 1; if (f == NULL) { info_tailcall(ar); return status; } for (; *what; what++) { switch (*what) { case 'S': { funcinfo(ar, f); break; } case 'l': { ar->currentline = (ci) ? currentline(L, ci) : -1; break; } case 'u': { ar->nups = f->c.nupvalues; break; } case 'n': { ar->namewhat = (ci) ? getfuncname(L, ci, &ar->name) : NULL; 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 *f = NULL; CallInfo *ci = NULL; lua_lock(L); if (*what == '>') { StkId func = L->top - 1; luai_apicheck(L, ttisfunction(func)); what++; /* skip the '>' */ f = clvalue(func); L->top--; /* pop function */ } else if (ar->i_ci != 0) { /* no tail call? */ ci = L->base_ci + ar->i_ci; lua_assert(ttisfunction(ci->func)); f = clvalue(ci->func); } status = auxgetinfo(L, what, ar, f, ci); if (strchr(what, 'f')) { if (f == NULL) setnilvalue(L->top); else setclvalue(L, L->top, f); incr_top(L); } if (strchr(what, 'L')) collectvalidlines(L, f); lua_unlock(L); return status; } /* ** {====================================================== ** Symbolic Execution and code checker ** ======================================================= */ #define check(x) if (!(x)) return 0; #define checkjump(pt,pc) check(0 <= pc && pc < pt->sizecode) #define checkreg(pt,reg) check((reg) < (pt)->maxstacksize) static int precheck (const Proto *pt) { check(pt->maxstacksize <= MAXSTACK); check(pt->numparams+(pt->is_vararg & VARARG_HASARG) <= pt->maxstacksize); check(!(pt->is_vararg & VARARG_NEEDSARG) || (pt->is_vararg & VARARG_HASARG)); check(pt->sizeupvalues <= pt->nups); check(pt->sizelineinfo == pt->sizecode || pt->sizelineinfo == 0); check(pt->sizecode > 0 && GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN); return 1; } #define checkopenop(pt,pc) luaG_checkopenop((pt)->code[(pc)+1]) int luaG_checkopenop (Instruction i) { switch (GET_OPCODE(i)) { case OP_CALL: case OP_TAILCALL: case OP_RETURN: case OP_SETLIST: { check(GETARG_B(i) == 0); return 1; } default: return 0; /* invalid instruction after an open call */ } } static int checkArgMode (const Proto *pt, int r, enum OpArgMask mode) { switch (mode) { case OpArgN: check(r == 0); break; case OpArgU: break; case OpArgR: checkreg(pt, r); break; case OpArgK: check(ISK(r) ? INDEXK(r) < pt->sizek : r < pt->maxstacksize); break; } return 1; } static Instruction symbexec (const Proto *pt, int lastpc, int reg) { int pc; int last; /* stores position of last instruction that changed `reg' */ last = pt->sizecode-1; /* points to final return (a `neutral' instruction) */ check(precheck(pt)); for (pc = 0; pc < lastpc; pc++) { Instruction i = pt->code[pc]; OpCode op = GET_OPCODE(i); int a = GETARG_A(i); int b = 0; int c = 0; check(op < NUM_OPCODES); checkreg(pt, a); switch (getOpMode(op)) { case iABC: { b = GETARG_B(i); c = GETARG_C(i); check(checkArgMode(pt, b, getBMode(op))); check(checkArgMode(pt, c, getCMode(op))); break; } case iABx: { b = GETARG_Bx(i); if (getBMode(op) == OpArgK) check(b < pt->sizek); break; } case iAsBx: { b = GETARG_sBx(i); if (getBMode(op) == OpArgR) { int dest = pc+1+b; check(0 <= dest && dest < pt->sizecode); if (dest > 0) { int j; /* check that it does not jump to a setlist count; this is tricky, because the count from a previous setlist may have the same value of an invalid setlist; so, we must go all the way back to the first of them (if any) */ for (j = 0; j < dest; j++) { Instruction d = pt->code[dest-1-j]; if (!(GET_OPCODE(d) == OP_SETLIST && GETARG_C(d) == 0)) break; } /* if 'j' is even, previous value is not a setlist (even if it looks like one) */ check((j&1) == 0); } } break; } } if (testAMode(op)) { if (a == reg) last = pc; /* change register `a' */ } if (testTMode(op)) { check(pc+2 < pt->sizecode); /* check skip */ check(GET_OPCODE(pt->code[pc+1]) == OP_JMP); } switch (op) { case OP_LOADBOOL: { if (c == 1) { /* does it jump? */ check(pc+2 < pt->sizecode); /* check its jump */ check(GET_OPCODE(pt->code[pc+1]) != OP_SETLIST || GETARG_C(pt->code[pc+1]) != 0); } break; } case OP_LOADNIL: { if (a <= reg && reg <= b) last = pc; /* set registers from `a' to `b' */ break; } case OP_GETUPVAL: case OP_SETUPVAL: { check(b < pt->nups); break; } case OP_GETGLOBAL: case OP_SETGLOBAL: { check(ttisstring(&pt->k[b])); break; } case OP_SELF: { checkreg(pt, a+1); if (reg == a+1) last = pc; break; } case OP_CONCAT: { check(b < c); /* at least two operands */ break; } case OP_TFORLOOP: { check(c >= 1); /* at least one result (control variable) */ checkreg(pt, a+2+c); /* space for results */ if (reg >= a+2) last = pc; /* affect all regs above its base */ break; } case OP_FORLOOP: case OP_FORPREP: checkreg(pt, a+3); /* go through */ case OP_JMP: { int dest = pc+1+b; /* not full check and jump is forward and do not skip `lastpc'? */ if (reg != NO_REG && pc < dest && dest <= lastpc) pc += b; /* do the jump */ break; } case OP_CALL: case OP_TAILCALL: { if (b != 0) { checkreg(pt, a+b-1); } c--; /* c = num. returns */ if (c == LUA_MULTRET) { check(checkopenop(pt, pc)); } else if (c != 0) checkreg(pt, a+c-1); if (reg >= a) last = pc; /* affect all registers above base */ break; } case OP_RETURN: { b--; /* b = num. returns */ if (b > 0) checkreg(pt, a+b-1); break; } case OP_SETLIST: { if (b > 0) checkreg(pt, a + b); if (c == 0) { pc++; check(pc < pt->sizecode - 1); } break; } case OP_CLOSURE: { int nup, j; check(b < pt->sizep); nup = pt->p[b]->nups; check(pc + nup < pt->sizecode); for (j = 1; j <= nup; j++) { OpCode op1 = GET_OPCODE(pt->code[pc + j]); check(op1 == OP_GETUPVAL || op1 == OP_MOVE); } if (reg != NO_REG) /* tracing? */ pc += nup; /* do not 'execute' these pseudo-instructions */ break; } case OP_VARARG: { check((pt->is_vararg & VARARG_ISVARARG) && !(pt->is_vararg & VARARG_NEEDSARG)); b--; if (b == LUA_MULTRET) check(checkopenop(pt, pc)); checkreg(pt, a+b-1); break; } default: break; } } return pt->code[last]; } #undef check #undef checkjump #undef checkreg /* }====================================================== */ int luaG_checkcode (const Proto *pt) { return (symbexec(pt, pt->sizecode, NO_REG) != 0); } static const char *kname (Proto *p, int c) { if (ISK(c) && ttisstring(&p->k[INDEXK(c)])) return svalue(&p->k[INDEXK(c)]); else return "?"; } static const char *getobjname (lua_State *L, CallInfo *ci, int stackpos, const char **name) { if (isLua(ci)) { /* a Lua function? */ Proto *p = ci_func(ci)->l.p; int pc = currentpc(L, ci); Instruction i; *name = luaF_getlocalname(p, stackpos+1, pc); if (*name) /* is a local? */ return "local"; i = symbexec(p, pc, stackpos); /* try symbolic execution */ lua_assert(pc != -1); switch (GET_OPCODE(i)) { case OP_GETGLOBAL: { int g = GETARG_Bx(i); /* global index */ lua_assert(ttisstring(&p->k[g])); *name = svalue(&p->k[g]); return "global"; } case OP_MOVE: { int a = GETARG_A(i); int b = GETARG_B(i); /* move from `b' to `a' */ if (b < a) return getobjname(L, ci, b, name); /* get name for `b' */ break; } case OP_GETTABLE: { int k = GETARG_C(i); /* key index */ *name = kname(p, k); return "field"; } case OP_GETUPVAL: { int u = GETARG_B(i); /* upvalue index */ *name = p->upvalues ? getstr(p->upvalues[u]) : "?"; return "upvalue"; } case OP_SELF: { int k = GETARG_C(i); /* key index */ *name = kname(p, k); return "method"; } default: break; } } return NULL; /* no useful name found */ } static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) { Instruction i; if ((isLua(ci) && ci->tailcalls > 0) || !isLua(ci - 1)) return NULL; /* calling function is not Lua (or is unknown) */ ci--; /* calling function */ i = ci_func(ci)->l.p->code[currentpc(L, ci)]; if (GET_OPCODE(i) == OP_CALL || GET_OPCODE(i) == OP_TAILCALL || GET_OPCODE(i) == OP_TFORLOOP) return getobjname(L, ci, GETARG_A(i), name); else return NULL; /* no useful name can be found */ } /* only ANSI way to check whether a pointer points to an array */ static int isinstack (CallInfo *ci, const TValue *o) { StkId p; for (p = ci->base; p < ci->top; p++) if (o == p) return 1; return 0; } void luaG_typeerror (lua_State *L, const TValue *o, const char *op) { const char *name = NULL; const char *t = luaT_typenames[ttype(o)]; const char *kind = (isinstack(L->ci, o)) ? getobjname(L, L->ci, cast_int(o - L->base), &name) : NULL; if (kind) luaG_runerror(L, "attempt to %s %s " LUA_QS " (a %s value)", op, kind, name, t); else luaG_runerror(L, "attempt to %s a %s value", op, t); } void luaG_concaterror (lua_State *L, StkId p1, StkId p2) { if (ttisstring(p1) || ttisnumber(p1)) p1 = p2; lua_assert(!ttisstring(p1) && !ttisnumber(p1)); luaG_typeerror(L, p1, "concatenate"); } void luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) { TValue temp; if (luaV_tonumber(p1, &temp) == NULL) p2 = p1; /* first operand is wrong */ luaG_typeerror(L, p2, "perform arithmetic on"); } int luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) { const char *t1 = luaT_typenames[ttype(p1)]; const char *t2 = luaT_typenames[ttype(p2)]; if (t1[2] == t2[2]) luaG_runerror(L, "attempt to compare two %s values", t1); else luaG_runerror(L, "attempt to compare %s with %s", t1, t2); return 0; } static void addinfo (lua_State *L, const char *msg) { CallInfo *ci = L->ci; if (isLua(ci)) { /* is Lua code? */ char buff[LUA_IDSIZE]; /* add file:line information */ int line = currentline(L, ci); luaO_chunkid(buff, getstr(getluaproto(ci)->source), LUA_IDSIZE); luaO_pushfstring(L, "%s:%d: %s", buff, line, msg); } } void luaG_errormsg (lua_State *L) { if (L->errfunc != 0) { /* is there an error handling function? */ StkId errfunc = restorestack(L, L->errfunc); if (!ttisfunction(errfunc)) luaD_throw(L, LUA_ERRERR); setobjs2s(L, L->top, L->top - 1); /* move argument */ setobjs2s(L, L->top - 1, errfunc); /* push function */ incr_top(L); luaD_call(L, L->top - 2, 1); /* call it */ } luaD_throw(L, LUA_ERRRUN); } void luaG_runerror (lua_State *L, const char *fmt, ...) { va_list argp; va_start(argp, fmt); addinfo(L, luaO_pushvfstring(L, fmt, argp)); va_end(argp); luaG_errormsg(L); }