eval.c

早期freebsd实现

	    rslen = old_rslen;
#ifdef DEBUGGING
	    tmps = "READ";
#endif
	    break;
	}
#ifdef DEBUGGING
	if (debug & 8)
	    deb("%d.%s = '%s'\n",anum,tmps,str_peek(st[sp]));
#endif
	if (anum < 8)
	    arglast[anum] = sp;
    }

    st += arglast[0];
#ifdef SMALLSWITCHES
    if (optype < O_CHOWN)
#endif
    switch (optype) {
    case O_RCAT:
	STABSET(str);
	break;
    case O_ITEM:
	if (gimme == G_ARRAY)
	    goto array_return;
	/* FALL THROUGH */
    case O_SCALAR:
	STR_SSET(str,st[1]);
	STABSET(str);
	break;
    case O_ITEM2:
	if (gimme == G_ARRAY)
	    goto array_return;
	--anum;
	STR_SSET(str,st[arglast[anum]-arglast[0]]);
	STABSET(str);
	break;
    case O_ITEM3:
	if (gimme == G_ARRAY)
	goto array_return;
	--anum;
	STR_SSET(str,st[arglast[anum]-arglast[0]]);
	STABSET(str);
	break;
    case O_CONCAT:
	STR_SSET(str,st[1]);
	str_scat(str,st[2]);
	STABSET(str);
	break;
    case O_REPEAT:
	if (gimme == G_ARRAY && arg[1].arg_flags & AF_ARYOK) {
	    sp = do_repeatary(arglast);
	    goto array_return;
	}
	STR_SSET(str,st[1]);
	anum = (int)str_gnum(st[2]);
	if (anum >= 1) {
	    tmpstr = Str_new(50, 0);
	    tmps = str_get(str);
	    str_nset(tmpstr,tmps,str->str_cur);
	    tmps = str_get(tmpstr);	/* force to be string */
	    STR_GROW(str, (anum * str->str_cur) + 1);
	    repeatcpy(str->str_ptr, tmps, tmpstr->str_cur, anum);
	    str->str_cur *= anum;
	    str->str_ptr[str->str_cur] = '\0';
	    str->str_nok = 0;
	    str_free(tmpstr);
	}
	else {
	    if (dowarn && st[2]->str_pok && !looks_like_number(st[2]))
		warn("Right operand of x is not numeric");
	    str_sset(str,&str_no);
	}
	STABSET(str);
	break;
    case O_MATCH:
	sp = do_match(str,arg,
	  gimme,arglast);
	if (gimme == G_ARRAY)
	    goto array_return;
	STABSET(str);
	break;
    case O_NMATCH:
	sp = do_match(str,arg,
	  G_SCALAR,arglast);
	str_sset(str, str_true(str) ? &str_no : &str_yes);
	STABSET(str);
	break;
    case O_SUBST:
	sp = do_subst(str,arg,arglast[0]);
	goto array_return;
    case O_NSUBST:
	sp = do_subst(str,arg,arglast[0]);
	str = arg->arg_ptr.arg_str;
	str_set(str, str_true(str) ? No : Yes);
	goto array_return;
    case O_ASSIGN:
	if (arg[1].arg_flags & AF_ARYOK) {
	    if (arg->arg_len == 1) {
		arg->arg_type = O_LOCAL;
		goto local;
	    }
	    else {
		arg->arg_type = O_AASSIGN;
		goto aassign;
	    }
	}
	else {
	    arg->arg_type = O_SASSIGN;
	    goto sassign;
	}
    case O_LOCAL:
      local:
	arglast[2] = arglast[1];	/* push a null array */
	/* FALL THROUGH */
    case O_AASSIGN:
      aassign:
	sp = do_assign(arg,
	  gimme,arglast);
	goto array_return;
    case O_SASSIGN:
      sassign:
#ifdef TAINT
	if (tainted && !st[2]->str_tainted)
	    tainted = 0;
#endif
	STR_SSET(str, st[2]);
	STABSET(str);
	break;
    case O_CHOP:
	st -= arglast[0];
	str = arg->arg_ptr.arg_str;
	for (sp = arglast[0] + 1; sp <= arglast[1]; sp++)
	    do_chop(str,st[sp]);
	st += arglast[0];
	break;
    case O_DEFINED:
	if (arg[1].arg_type & A_DONT) {
	    sp = do_defined(str,arg,
		  gimme,arglast);
	    goto array_return;
	}
	else if (str->str_pok || str->str_nok)
	    goto say_yes;
	goto say_no;
    case O_UNDEF:
	if (arg[1].arg_type & A_DONT) {
	    sp = do_undef(str,arg,
	      gimme,arglast);
	    goto array_return;
	}
	else if (str != stab_val(defstab)) {
	    if (str->str_len) {
		if (str->str_state == SS_INCR)
		    Str_Grow(str,0);
		Safefree(str->str_ptr);
		str->str_ptr = Nullch;
		str->str_len = 0;
	    }
	    str->str_pok = str->str_nok = 0;
	    STABSET(str);
	}
	goto say_undef;
    case O_STUDY:
	sp = do_study(str,arg,
	  gimme,arglast);
	goto array_return;
    case O_POW:
	value = str_gnum(st[1]);
	value = pow(value,str_gnum(st[2]));
	goto donumset;
    case O_MULTIPLY:
	value = str_gnum(st[1]);
	value *= str_gnum(st[2]);
	goto donumset;
    case O_DIVIDE:
	if ((value = str_gnum(st[2])) == 0.0)
	    fatal("Illegal division by zero");
#ifdef SLOPPYDIVIDE
	/* insure that 20./5. == 4. */
	{
	    double x;
	    int    k;
	    x =  str_gnum(st[1]);
	    if ((double)(int)x     == x &&
		(double)(int)value == value &&
		(k = (int)x/(int)value)*(int)value == (int)x) {
		value = k;
	    } else {
		value = x/value;
	    }
	}
#else
	value = str_gnum(st[1]) / value;
#endif
	goto donumset;
    case O_MODULO:
	tmpulong = (unsigned long) str_gnum(st[2]);
    	if (tmpulong == 0L)
    	    fatal("Illegal modulus zero");
#ifndef lint
	value = str_gnum(st[1]);
	if (value >= 0.0)
	    value = (double)(((unsigned long)value) % tmpulong);
	else {
	    tmplong = (long)value;
	    value = (double)(tmpulong - ((-tmplong - 1) % tmpulong)) - 1;
	}
#endif
	goto donumset;
    case O_ADD:
	value = str_gnum(st[1]);
	value += str_gnum(st[2]);
	goto donumset;
    case O_SUBTRACT:
	value = str_gnum(st[1]);
	value -= str_gnum(st[2]);
	goto donumset;
    case O_LEFT_SHIFT:
	value = str_gnum(st[1]);
	anum = (int)str_gnum(st[2]);
#ifndef lint
	value = (double)(U_L(value) << anum);
#endif
	goto donumset;
    case O_RIGHT_SHIFT:
	value = str_gnum(st[1]);
	anum = (int)str_gnum(st[2]);
#ifndef lint
	value = (double)(U_L(value) >> anum);
#endif
	goto donumset;
    case O_LT:
	value = str_gnum(st[1]);
	value = (value < str_gnum(st[2])) ? 1.0 : 0.0;
	goto donumset;
    case O_GT:
	value = str_gnum(st[1]);
	value = (value > str_gnum(st[2])) ? 1.0 : 0.0;
	goto donumset;
    case O_LE:
	value = str_gnum(st[1]);
	value = (value <= str_gnum(st[2])) ? 1.0 : 0.0;
	goto donumset;
    case O_GE:
	value = str_gnum(st[1]);
	value = (value >= str_gnum(st[2])) ? 1.0 : 0.0;
	goto donumset;
    case O_EQ:
	if (dowarn) {
	    if ((!st[1]->str_nok && !looks_like_number(st[1])) ||
		(!st[2]->str_nok && !looks_like_number(st[2])) )
		warn("Possible use of == on string value");
	}
	value = str_gnum(st[1]);
	value = (value == str_gnum(st[2])) ? 1.0 : 0.0;
	goto donumset;
    case O_NE:
	value = str_gnum(st[1]);
	value = (value != str_gnum(st[2])) ? 1.0 : 0.0;
	goto donumset;
    case O_NCMP:
	value = str_gnum(st[1]);
	value -= str_gnum(st[2]);
	if (value > 0.0)
	    value = 1.0;
	else if (value < 0.0)
	    value = -1.0;
	goto donumset;
    case O_BIT_AND:
	if (!sawvec || st[1]->str_nok || st[2]->str_nok) {
	    value = str_gnum(st[1]);
#ifndef lint
	    value = (double)(U_L(value) & U_L(str_gnum(st[2])));
#endif
	    goto donumset;
	}
	else
	    do_vop(optype,str,st[1],st[2]);
	break;
    case O_XOR:
	if (!sawvec || st[1]->str_nok || st[2]->str_nok) {
	    value = str_gnum(st[1]);
#ifndef lint
	    value = (double)(U_L(value) ^ U_L(str_gnum(st[2])));
#endif
	    goto donumset;
	}
	else
	    do_vop(optype,str,st[1],st[2]);
	break;
    case O_BIT_OR:
	if (!sawvec || st[1]->str_nok || st[2]->str_nok) {
	    value = str_gnum(st[1]);
#ifndef lint
	    value = (double)(U_L(value) | U_L(str_gnum(st[2])));
#endif
	    goto donumset;
	}
	else
	    do_vop(optype,str,st[1],st[2]);
	break;
/* use register in evaluating str_true() */
    case O_AND:
	if (str_true(st[1])) {
	    anum = 2;
	    optype = O_ITEM2;
	    argflags = arg[anum].arg_flags;
	    if (gimme == G_ARRAY)
		argflags |= AF_ARYOK;
	    argtype = arg[anum].arg_type & A_MASK;
	    argptr = arg[anum].arg_ptr;
	    maxarg = anum = 1;
	    sp = arglast[0];
	    st -= sp;
	    goto re_eval;
	}
	else {
	    if (assigning) {
		str_sset(str, st[1]);
		STABSET(str);
	    }
	    else
		str = st[1];
	    break;
	}
    case O_OR:
	if (str_true(st[1])) {
	    if (assigning) {
		str_sset(str, st[1]);
		STABSET(str);
	    }
	    else
		str = st[1];
	    break;
	}
	else {
	    anum = 2;
	    optype = O_ITEM2;
	    argflags = arg[anum].arg_flags;
	    if (gimme == G_ARRAY)
		argflags |= AF_ARYOK;
	    argtype = arg[anum].arg_type & A_MASK;
	    argptr = arg[anum].arg_ptr;
	    maxarg = anum = 1;
	    sp = arglast[0];
	    st -= sp;
	    goto re_eval;
	}
    case O_COND_EXPR:
	anum = (str_true(st[1]) ? 2 : 3);
	optype = (anum == 2 ? O_ITEM2 : O_ITEM3);
	argflags = arg[anum].arg_flags;
	if (gimme == G_ARRAY)
	    argflags |= AF_ARYOK;
	argtype = arg[anum].arg_type & A_MASK;
	argptr = arg[anum].arg_ptr;
	maxarg = anum = 1;
	sp = arglast[0];
	st -= sp;
	goto re_eval;
    case O_COMMA:
	if (gimme == G_ARRAY)
	    goto array_return;
	str = st[2];
	break;
    case O_NEGATE:
	value = -str_gnum(st[1]);
	goto donumset;
    case O_NOT:
#ifdef NOTNOT
	{ char xxx = str_true(st[1]); value = (double) !xxx; }
#else
	value = (double) !str_true(st[1]);
#endif
	goto donumset;
    case O_COMPLEMENT:
	if (!sawvec || st[1]->str_nok) {
#ifndef lint
	    value = (double) ~U_L(str_gnum(st[1]));
#endif
	    goto donumset;
	}
	else {
	    STR_SSET(str,st[1]);
	    tmps = str_get(str);
	    for (anum = str->str_cur; anum; anum--, tmps++)
		*tmps = ~*tmps;
	}
	break;
    case O_SELECT:
	stab_efullname(str,defoutstab);
	if (maxarg > 0) {
	    if ((arg[1].arg_type & A_MASK) == A_WORD)
		defoutstab = arg[1].arg_ptr.arg_stab;
	    else
		defoutstab = stabent(str_get(st[1]),TRUE);
	    if (!stab_io(defoutstab))
		stab_io(defoutstab) = stio_new();
	    curoutstab = defoutstab;
	}
	STABSET(str);
	break;
    case O_WRITE:
	if (maxarg == 0)
	    stab = defoutstab;
	else if ((arg[1].arg_type & A_MASK) == A_WORD) {
	    if (!(stab = arg[1].arg_ptr.arg_stab))
		stab = defoutstab;
	}
	else
	    stab = stabent(str_get(st[1]),TRUE);
	if (!stab_io(stab)) {
	    str_set(str, No);
	    STABSET(str);
	    break;
	}
	curoutstab = stab;
	fp = stab_io(stab)->ofp;
	debarg = arg;
	if (stab_io(stab)->fmt_stab)
	    form = stab_form(stab_io(stab)->fmt_stab);
	else
	    form = stab_form(stab);
	if (!form || !fp) {
	    if (dowarn) {
		if (form)
		    warn("No format for filehandle");
		else {
		    if (stab_io(stab)->ifp)
			warn("Filehandle only opened for input");
		    else
			warn("Write on closed filehandle");
		}
	    }
	    str_set(str, No);
	    STABSET(str);
	    break;
	}
	format(&outrec,form,sp);
	do_write(&outrec,stab,sp);
	if (stab_io(stab)->flags & IOF_FLUSH)
	    (void)fflush(fp);
	str_set(str, Yes);
	STABSET(str);
	break;
    case O_DBMOPEN:
#ifdef SOME_DBM
	anum = arg[1].arg_type & A_MASK;
	if (anum == A_WORD || anum == A_STAB)
	    stab = arg[1].arg_ptr.arg_stab;
	else
	    stab = stabent(str_get(st[1]),TRUE);
	if (st[3]->str_nok || st[3]->str_pok)
	    anum = (int)str_gnum(st[3]);
	else
	    anum = -1;
	value = (double)hdbmopen(stab_hash(stab),str_get(st[2]),anum);
	goto donumset;
#else
	fatal("No dbm or ndbm on this machine");
#endif
    case O_DBMCLOSE:
#ifdef SOME_DBM
	anum = arg[1].arg_type & A_MASK;
	if (anum == A_WORD || anum == A_STAB)
	    stab = arg[1].arg_ptr.arg_stab;
	else
	    stab = stabent(str_get(st[1]),TRUE);
	hdbmclose(stab_hash(stab));
	goto say_yes;
#else
	fatal("No dbm or ndbm on this machine");
#endif
    case O_OPEN:
	if ((arg[1].arg_type & A_MASK) == A_WORD)
	    stab = arg[1].arg_ptr.arg_stab;
	else
	    stab = stabent(str_get(st[1]),TRUE);
	tmps = str_get(st[2]);
	if (do_open(stab,tmps,st[2]->str_cur)) {
	    value = (double)forkprocess;
	    stab_io(stab)->lines = 0;
	    goto donumset;
	}
	else if (forkprocess == 0)		/* we are a new child */
	    goto say_zero;
	else
	    goto say_undef;
	/* break; */
    case O_TRANS:
	value = (double) do_trans(str,arg);
	str = arg->arg_ptr.arg_str;
	goto donumset;
    case O_NTRANS:
	str_set(arg->arg_ptr.arg_str, do_trans(str,arg) == 0 ? Yes : No);
	str = arg->arg_ptr.arg_str;
	break;
    case O_CLOSE:
	if (maxarg == 0)
	    stab = defoutstab;
	else if ((arg[1].arg_type & A_MASK) == A_WORD)
	    stab = arg[1].arg_ptr.arg_stab;
	else
	    stab = stabent(str_get(st[1]),TRUE);
	str_set(str, do_close(stab,TRUE) ? Yes : No );
	STABSET(str);
	break;
    case O_EACH:
	sp = do_each(str,stab_hash(arg[1].arg_ptr.arg_stab),
	  gimme,arglast);
	goto array_return;
    case O_VALUES:
    case O_KEYS:
	sp = do_kv(str,stab_hash(arg[1].arg_ptr.arg_stab), optype,
	  gimme,arglast);
	goto array_return;
    case O_LARRAY:
	str->str_nok = str->str_pok = 0;
	str->str_u.str_stab = arg[1].arg_ptr.arg_stab;
	str->str_state = SS_ARY;
	break;
    case O_ARRAY:
	ary = stab_array(arg[1].arg_ptr.arg_stab);
	maxarg = ary->ary_fill + 1;
	if (gimme == G_ARRAY) { /* array wanted */
	    sp = arglast[0];
	    st -= sp;
	    if (maxarg > 0 && sp + maxarg > stack->ary_max) {
		astore(stack,sp + maxarg, Nullstr);
		st = stack->ary_array;
	    }
	    st += sp;
	    Copy(ary->ary_array, &st[1], maxarg, STR*);
	    sp += maxarg;
	    goto array_return;
	}
	else {
	    value = (double)maxarg;
	    goto donumset;
	}
    case O_AELEM:
	anum = ((int)str_gnum(st[2])) - arybase;
	str = afetch(stab_array(arg[1].arg_ptr.arg_stab),anum,FALSE);
	break;
    case O_DELETE:
	tmpstab = arg[1].arg_ptr.arg_stab;
	tmps = str_get(st[2]);
	str = hdelete(stab_hash(tmpstab),tmps,st[2]->str_cur);
	if (tmpstab == envstab)
	    my_setenv(tmps,Nullch);