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** $Id: ldebug.c,v 2.29.1.6 2008/05/08 16:56:26 roberto Exp $
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** See Copyright Notice in lua.h
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static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name);
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static int currentpc (lua_State *L, CallInfo *ci) {
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if (!isLua(ci)) return -1; /* function is not a Lua function? */
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ci->savedpc = L->savedpc;
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return pcRel(ci->savedpc, ci_func(ci)->l.p);
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static int currentline (lua_State *L, CallInfo *ci) {
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int pc = currentpc(L, ci);
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return -1; /* only active lua functions have current-line information */
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return getline(ci_func(ci)->l.p, pc);
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** this function can be called asynchronous (e.g. during a signal)
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LUA_API int lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
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if (func == NULL || mask == 0) { /* turn off hooks? */
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L->basehookcount = count;
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L->hookmask = cast_byte(mask);
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LUA_API lua_Hook lua_gethook (lua_State *L) {
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LUA_API int lua_gethookmask (lua_State *L) {
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LUA_API int lua_gethookcount (lua_State *L) {
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return L->basehookcount;
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LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
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for (ci = L->ci; level > 0 && ci > L->base_ci; ci--) {
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if (f_isLua(ci)) /* Lua function? */
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level -= ci->tailcalls; /* skip lost tail calls */
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if (level == 0 && ci > L->base_ci) { /* level found? */
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ar->i_ci = cast_int(ci - L->base_ci);
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else if (level < 0) { /* level is of a lost tail call? */
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else status = 0; /* no such level */
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static Proto *getluaproto (CallInfo *ci) {
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return (isLua(ci) ? ci_func(ci)->l.p : NULL);
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static const char *findlocal (lua_State *L, CallInfo *ci, int n) {
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Proto *fp = getluaproto(ci);
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if (fp && (name = luaF_getlocalname(fp, n, currentpc(L, ci))) != NULL)
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return name; /* is a local variable in a Lua function */
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StkId limit = (ci == L->ci) ? L->top : (ci+1)->func;
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if (limit - ci->base >= n && n > 0) /* is 'n' inside 'ci' stack? */
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return "(*temporary)";
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LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
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CallInfo *ci = L->base_ci + ar->i_ci;
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const char *name = findlocal(L, ci, n);
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luaA_pushobject(L, ci->base + (n - 1));
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LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
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CallInfo *ci = L->base_ci + ar->i_ci;
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const char *name = findlocal(L, ci, n);
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setobjs2s(L, ci->base + (n - 1), L->top - 1);
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L->top--; /* pop value */
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static void funcinfo (lua_Debug *ar, Closure *cl) {
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ar->linedefined = -1;
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ar->lastlinedefined = -1;
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ar->source = getstr(cl->l.p->source);
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ar->linedefined = cl->l.p->linedefined;
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ar->lastlinedefined = cl->l.p->lastlinedefined;
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ar->what = (ar->linedefined == 0) ? "main" : "Lua";
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luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
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static void info_tailcall (lua_Debug *ar) {
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ar->name = ar->namewhat = "";
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ar->lastlinedefined = ar->linedefined = ar->currentline = -1;
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ar->source = "=(tail call)";
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luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
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static void collectvalidlines (lua_State *L, Closure *f) {
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if (f == NULL || f->c.isC) {
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Table *t = luaH_new(L, 0, 0);
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int *lineinfo = f->l.p->lineinfo;
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for (i=0; i<f->l.p->sizelineinfo; i++)
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setbvalue(luaH_setnum(L, t, lineinfo[i]), 1);
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sethvalue(L, L->top, t);
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static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
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Closure *f, CallInfo *ci) {
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for (; *what; what++) {
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ar->currentline = (ci) ? currentline(L, ci) : -1;
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ar->nups = f->c.nupvalues;
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ar->namewhat = (ci) ? getfuncname(L, ci, &ar->name) : NULL;
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if (ar->namewhat == NULL) {
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ar->namewhat = ""; /* not found */
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case 'f': /* handled by lua_getinfo */
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default: status = 0; /* invalid option */
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LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
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StkId func = L->top - 1;
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luai_apicheck(L, ttisfunction(func));
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what++; /* skip the '>' */
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L->top--; /* pop function */
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else if (ar->i_ci != 0) { /* no tail call? */
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ci = L->base_ci + ar->i_ci;
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lua_assert(ttisfunction(ci->func));
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f = clvalue(ci->func);
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status = auxgetinfo(L, what, ar, f, ci);
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if (strchr(what, 'f')) {
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if (f == NULL) setnilvalue(L->top);
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else setclvalue(L, L->top, f);
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if (strchr(what, 'L'))
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collectvalidlines(L, f);
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** {======================================================
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** Symbolic Execution and code checker
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** =======================================================
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#define check(x) if (!(x)) return 0;
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#define checkjump(pt,pc) check(0 <= pc && pc < pt->sizecode)
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#define checkreg(pt,reg) check((reg) < (pt)->maxstacksize)
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static int precheck (const Proto *pt) {
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check(pt->maxstacksize <= MAXSTACK);
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check(pt->numparams+(pt->is_vararg & VARARG_HASARG) <= pt->maxstacksize);
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check(!(pt->is_vararg & VARARG_NEEDSARG) ||
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(pt->is_vararg & VARARG_HASARG));
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check(pt->sizeupvalues <= pt->nups);
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check(pt->sizelineinfo == pt->sizecode || pt->sizelineinfo == 0);
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check(pt->sizecode > 0 && GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN);
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#define checkopenop(pt,pc) luaG_checkopenop((pt)->code[(pc)+1])
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int luaG_checkopenop (Instruction i) {
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switch (GET_OPCODE(i)) {
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check(GETARG_B(i) == 0);
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default: return 0; /* invalid instruction after an open call */
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static int checkArgMode (const Proto *pt, int r, enum OpArgMask mode) {
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case OpArgN: check(r == 0); break;
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case OpArgR: checkreg(pt, r); break;
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check(ISK(r) ? INDEXK(r) < pt->sizek : r < pt->maxstacksize);
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static Instruction symbexec (const Proto *pt, int lastpc, int reg) {
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int last; /* stores position of last instruction that changed `reg' */
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last = pt->sizecode-1; /* points to final return (a `neutral' instruction) */
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for (pc = 0; pc < lastpc; pc++) {
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Instruction i = pt->code[pc];
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OpCode op = GET_OPCODE(i);
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check(op < NUM_OPCODES);
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switch (getOpMode(op)) {
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check(checkArgMode(pt, b, getBMode(op)));
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check(checkArgMode(pt, c, getCMode(op)));
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if (getBMode(op) == OpArgK) check(b < pt->sizek);
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if (getBMode(op) == OpArgR) {
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check(0 <= dest && dest < pt->sizecode);
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/* check that it does not jump to a setlist count; this
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is tricky, because the count from a previous setlist may
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have the same value of an invalid setlist; so, we must
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go all the way back to the first of them (if any) */
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for (j = 0; j < dest; j++) {
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Instruction d = pt->code[dest-1-j];
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if (!(GET_OPCODE(d) == OP_SETLIST && GETARG_C(d) == 0)) break;
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/* if 'j' is even, previous value is not a setlist (even if
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it looks like one) */
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if (a == reg) last = pc; /* change register `a' */
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check(pc+2 < pt->sizecode); /* check skip */
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check(GET_OPCODE(pt->code[pc+1]) == OP_JMP);
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if (c == 1) { /* does it jump? */
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check(pc+2 < pt->sizecode); /* check its jump */
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check(GET_OPCODE(pt->code[pc+1]) != OP_SETLIST ||
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GETARG_C(pt->code[pc+1]) != 0);
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if (a <= reg && reg <= b)
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last = pc; /* set registers from `a' to `b' */
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check(ttisstring(&pt->k[b]));
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if (reg == a+1) last = pc;
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check(b < c); /* at least two operands */
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check(c >= 1); /* at least one result (control variable) */
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checkreg(pt, a+2+c); /* space for results */
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if (reg >= a+2) last = pc; /* affect all regs above its base */
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/* not full check and jump is forward and do not skip `lastpc'? */
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if (reg != NO_REG && pc < dest && dest <= lastpc)
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pc += b; /* do the jump */
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c--; /* c = num. returns */
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if (c == LUA_MULTRET) {
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check(checkopenop(pt, pc));
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if (reg >= a) last = pc; /* affect all registers above base */
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b--; /* b = num. returns */
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if (b > 0) checkreg(pt, a+b-1);
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if (b > 0) checkreg(pt, a + b);
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check(pc < pt->sizecode - 1);
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check(b < pt->sizep);
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nup = pt->p[b]->nups;
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check(pc + nup < pt->sizecode);
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for (j = 1; j <= nup; j++) {
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OpCode op1 = GET_OPCODE(pt->code[pc + j]);
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check(op1 == OP_GETUPVAL || op1 == OP_MOVE);
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if (reg != NO_REG) /* tracing? */
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pc += nup; /* do not 'execute' these pseudo-instructions */
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check((pt->is_vararg & VARARG_ISVARARG) &&
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!(pt->is_vararg & VARARG_NEEDSARG));
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if (b == LUA_MULTRET) check(checkopenop(pt, pc));
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return pt->code[last];
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/* }====================================================== */
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int luaG_checkcode (const Proto *pt) {
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return (symbexec(pt, pt->sizecode, NO_REG) != 0);
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static const char *kname (Proto *p, int c) {
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if (ISK(c) && ttisstring(&p->k[INDEXK(c)]))
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return svalue(&p->k[INDEXK(c)]);
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static const char *getobjname (lua_State *L, CallInfo *ci, int stackpos,
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if (isLua(ci)) { /* a Lua function? */
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Proto *p = ci_func(ci)->l.p;
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int pc = currentpc(L, ci);
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*name = luaF_getlocalname(p, stackpos+1, pc);
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if (*name) /* is a local? */
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i = symbexec(p, pc, stackpos); /* try symbolic execution */
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lua_assert(pc != -1);
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switch (GET_OPCODE(i)) {
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int g = GETARG_Bx(i); /* global index */
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lua_assert(ttisstring(&p->k[g]));
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*name = svalue(&p->k[g]);
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int b = GETARG_B(i); /* move from `b' to `a' */
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return getobjname(L, ci, b, name); /* get name for `b' */
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int k = GETARG_C(i); /* key index */
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int u = GETARG_B(i); /* upvalue index */
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*name = p->upvalues ? getstr(p->upvalues[u]) : "?";
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int k = GETARG_C(i); /* key index */
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return NULL; /* no useful name found */
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static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
546
if ((isLua(ci) && ci->tailcalls > 0) || !isLua(ci - 1))
547
return NULL; /* calling function is not Lua (or is unknown) */
548
ci--; /* calling function */
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i = ci_func(ci)->l.p->code[currentpc(L, ci)];
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if (GET_OPCODE(i) == OP_CALL || GET_OPCODE(i) == OP_TAILCALL ||
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GET_OPCODE(i) == OP_TFORLOOP)
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return getobjname(L, ci, GETARG_A(i), name);
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return NULL; /* no useful name can be found */
558
/* only ANSI way to check whether a pointer points to an array */
559
static int isinstack (CallInfo *ci, const TValue *o) {
561
for (p = ci->base; p < ci->top; p++)
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if (o == p) return 1;
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void luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
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const char *name = NULL;
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const char *t = luaT_typenames[ttype(o)];
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const char *kind = (isinstack(L->ci, o)) ?
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getobjname(L, L->ci, cast_int(o - L->base), &name) :
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luaG_runerror(L, "attempt to %s %s " LUA_QS " (a %s value)",
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luaG_runerror(L, "attempt to %s a %s value", op, t);
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void luaG_concaterror (lua_State *L, StkId p1, StkId p2) {
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if (ttisstring(p1) || ttisnumber(p1)) p1 = p2;
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lua_assert(!ttisstring(p1) && !ttisnumber(p1));
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luaG_typeerror(L, p1, "concatenate");
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void luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) {
590
if (luaV_tonumber(p1, &temp) == NULL)
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p2 = p1; /* first operand is wrong */
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luaG_typeerror(L, p2, "perform arithmetic on");
596
int luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
597
const char *t1 = luaT_typenames[ttype(p1)];
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const char *t2 = luaT_typenames[ttype(p2)];
600
luaG_runerror(L, "attempt to compare two %s values", t1);
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luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
607
static void addinfo (lua_State *L, const char *msg) {
608
CallInfo *ci = L->ci;
609
if (isLua(ci)) { /* is Lua code? */
610
char buff[LUA_IDSIZE]; /* add file:line information */
611
int line = currentline(L, ci);
612
luaO_chunkid(buff, getstr(getluaproto(ci)->source), LUA_IDSIZE);
613
luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
618
void luaG_errormsg (lua_State *L) {
619
if (L->errfunc != 0) { /* is there an error handling function? */
620
StkId errfunc = restorestack(L, L->errfunc);
621
if (!ttisfunction(errfunc)) luaD_throw(L, LUA_ERRERR);
622
setobjs2s(L, L->top, L->top - 1); /* move argument */
623
setobjs2s(L, L->top - 1, errfunc); /* push function */
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luaD_call(L, L->top - 2, 1); /* call it */
627
luaD_throw(L, LUA_ERRRUN);
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void luaG_runerror (lua_State *L, const char *fmt, ...) {
634
addinfo(L, luaO_pushvfstring(L, fmt, argp));