[p5sagit/p5-mst-13.2.git] / ext / Opcode / Opcode.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

/* maxo shouldn't differ from MAXO but leave room anyway (see BOOT:)	*/
#define OP_MASK_BUF_SIZE (MAXO + 100)

static HV *op_named_bits;	/* cache shared for whole process	*/
static SV *opset_all;		/* mask with all bits set		*/
static IV  opset_len;		/* length of opmasks in bytes		*/
static int opcode_debug = 0;

static SV  *new_opset _((SV *old_opset));
static int  verify_opset _((SV *opset, int fatal));
static void set_opset_bits _((char *bitmap, SV *bitspec, int on, char *opname));
static void put_op_bitspec _((char *optag,  STRLEN len, SV *opset));
static SV  *get_op_bitspec _((char *opname, STRLEN len, int fatal));


/* Initialise our private op_named_bits HV.
 * It is first loaded with the name and number of each perl operator.
 * Then the builtin tags :none and :all are added.
 * Opcode.pm loads the standard optags from __DATA__
 */

static void
op_names_init(void)
{
    int i;
    STRLEN len;
    char *opname;
    char *bitmap;

    op_named_bits = newHV();
    for(i=0; i < maxo; ++i) {
	SV *sv;
	sv = newSViv(i);
	SvREADONLY_on(sv);
	hv_store(op_named_bits, op_name[i], strlen(op_name[i]), sv, 0);
    }

    put_op_bitspec(":none",0, sv_2mortal(new_opset(Nullsv)));

    opset_all = new_opset(Nullsv);
    bitmap = SvPV(opset_all, len);
    i = len-1; /* deal with last byte specially, see below */
    while(i-- > 0)
	bitmap[i] = 0xFF;
    /* Take care to set the right number of bits in the last byte */
    bitmap[len-1] = (maxo & 0x07) ? ~(0xFF << (maxo & 0x07)) : 0xFF;
    put_op_bitspec(":all",0, opset_all); /* don't mortalise */
}


/* Store a new tag definition. Always a mask.
 * The tag must not already be defined.
 * SV *mask is copied not referenced.
 */

static void
put_op_bitspec(char *optag, STRLEN len, SV *mask)
{
    SV **svp;
    verify_opset(mask,1);
    if (!len)
	len = strlen(optag);
    svp = hv_fetch(op_named_bits, optag, len, 1);
    if (SvOK(*svp))
	croak("Opcode tag \"%s\" already defined", optag);
    sv_setsv(*svp, mask);
    SvREADONLY_on(*svp);
}


/* Fetch a 'bits' entry for an opname or optag (IV/PV).
 * Note that we return the actual entry for speed.
 * Always sv_mortalcopy() if returing it to user code.
 */

static SV *
get_op_bitspec(char *opname, STRLEN len, int fatal)
{
    SV **svp;
    if (!len)
	len = strlen(opname);
    svp = hv_fetch(op_named_bits, opname, len, 0);
    if (!svp || !SvOK(*svp)) {
	if (!fatal)
	    return Nullsv;
	if (*opname == ':')
	    croak("Unknown operator tag \"%s\"", opname);
	if (*opname == '!')	/* XXX here later, or elsewhere? */
	    croak("Can't negate operators here (\"%s\")", opname);
	if (isALPHA(*opname))
	    croak("Unknown operator name \"%s\"", opname);
	croak("Unknown operator prefix \"%s\"", opname);
    }
    return *svp;
}


static SV *
new_opset(SV *old_opset)
{
    SV *opset;
    if (old_opset) {
	verify_opset(old_opset,1);
	opset = newSVsv(old_opset);
    }
    else {
	opset = newSV(opset_len);
	Zero(SvPVX(opset), opset_len + 1, char);
	SvCUR_set(opset, opset_len);
	(void)SvPOK_only(opset);
    }
    /* not mortalised here */
    return opset;
}


static int
verify_opset(SV *opset, int fatal)
{
    char *err = Nullch;
    if      (!SvOK(opset))              err = "undefined";
    else if (!SvPOK(opset))             err = "wrong type";
    else if (SvCUR(opset) != opset_len) err = "wrong size";
    if (err && fatal) {
	croak("Invalid opset: %s", err);
    }
    return !err;
}


static void
set_opset_bits(char *bitmap, SV *bitspec, int on, char *opname)
{
    if (SvIOK(bitspec)) {
	int myopcode = SvIV(bitspec);
	int offset = myopcode >> 3;
	int bit    = myopcode & 0x07;
	if (myopcode >= maxo || myopcode < 0)
	    croak("panic: opcode \"%s\" value %d is invalid", opname, myopcode);
	if (opcode_debug >= 2)
	    warn("set_opset_bits bit %2d (off=%d, bit=%d) %s %s\n",
			myopcode, offset, bit, opname, (on)?"on":"off");
	if (on)
	    bitmap[offset] |= 1 << bit;
	else
	    bitmap[offset] &= ~(1 << bit);
    }
    else if (SvPOK(bitspec) && SvCUR(bitspec) == opset_len) {

	STRLEN len;
	char *specbits = SvPV(bitspec, len);
	if (opcode_debug >= 2)
	    warn("set_opset_bits opset %s %s\n", opname, (on)?"on":"off");
	if (on) 
	    while(len-- > 0) bitmap[len] |=  specbits[len];
	else
	    while(len-- > 0) bitmap[len] &= ~specbits[len];
    }
    else
	croak("panic: invalid bitspec for \"%s\" (type %u)",
		opname, (unsigned)SvTYPE(bitspec));
}


static void
opmask_add(SV *opset)	/* THE ONLY FUNCTION TO EDIT op_mask ITSELF	*/
{
    int i,j;
    char *bitmask;
    STRLEN len;
    int myopcode = 0;

    verify_opset(opset,1);			/* croaks on bad opset	*/

    if (!op_mask)		/* caller must ensure op_mask exists	*/
	croak("Can't add to uninitialised op_mask");

    /* OPCODES ALREADY MASKED ARE NEVER UNMASKED. See opmask_addlocal()	*/

    bitmask = SvPV(opset, len);
    for (i=0; i < opset_len; i++) {
	U16 bits = bitmask[i];
	if (!bits) {	/* optimise for sparse masks */
	    myopcode += 8;
	    continue;
	}
	for (j=0; j < 8 && myopcode < maxo; )
	    op_mask[myopcode++] |= bits & (1 << j++);
    }
}

static void
opmask_addlocal(SV *opset, char *op_mask_buf) /* Localise op_mask then opmask_add() */
{
    char *orig_op_mask = op_mask;
    SAVEPPTR(op_mask);
    if (opcode_debug >= 2)
	SAVEDESTRUCTOR((void(*)_((void*)))warn,"op_mask restored");
    op_mask = &op_mask_buf[0];
    if (orig_op_mask)
	Copy(orig_op_mask, op_mask, maxo, char);
    else
	Zero(op_mask, maxo, char);
    opmask_add(opset);
}


MODULE = Opcode	PACKAGE = Opcode

PROTOTYPES: ENABLE

BOOT:
    assert(maxo < OP_MASK_BUF_SIZE);
    opset_len = (maxo + 7) / 8;
    if (opcode_debug >= 1)
	warn("opset_len %ld\n", (long)opset_len);
    op_names_init();


void
_safe_call_sv(package, mask, codesv)
    char *	package
    SV *	mask
    SV *	codesv
    PPCODE:
    char op_mask_buf[OP_MASK_BUF_SIZE];
    GV *gv;

    ENTER;

    opmask_addlocal(mask, op_mask_buf);

    save_aptr(&endav);
    endav = (AV*)sv_2mortal((SV*)newAV()); /* ignore END blocks for now	*/

    save_hptr(&defstash);		/* save current default stack	*/
    /* the assignment to global defstash changes our sense of 'main'	*/
    defstash = gv_stashpv(package, GV_ADDWARN); /* should exist already	*/

    /* defstash must itself contain a main:: so we'll add that now	*/
    /* take care with the ref counts (was cause of long standing bug)	*/
    /* XXX I'm still not sure if this is right, GV_ADDWARN should warn!	*/
    gv = gv_fetchpv("main::", GV_ADDWARN, SVt_PVHV);
    sv_free((SV*)GvHV(gv));
    GvHV(gv) = (HV*)SvREFCNT_inc(defstash);

    PUSHMARK(sp);
    perl_call_sv(codesv, GIMME|G_EVAL|G_KEEPERR); /* use callers context */
    SPAGAIN; /* for the PUTBACK added by xsubpp */
    LEAVE;


int
verify_opset(opset, fatal = 0)
    SV *opset
    int fatal


void
invert_opset(opset)
    SV *opset
    CODE:
    {
    char *bitmap;
    STRLEN len = opset_len;
    opset = new_opset(opset);	/* verify and clone opset */
    bitmap = SvPVX(opset);
    while(len-- > 0)
	bitmap[len] = ~bitmap[len];
    /* take care of extra bits beyond maxo in last byte	*/
    if (maxo & 07)
	bitmap[opset_len-1] &= ~(0xFF << (maxo & 0x07));
    }
    ST(0) = opset;


void
opset_to_ops(opset, desc = 0)
    SV *opset
    int	desc
    PPCODE:
    {
    STRLEN len;
    int i, j, myopcode;
    char *bitmap = SvPV(opset, len);
    char **names = (desc) ? op_desc : op_name;
    verify_opset(opset,1);
    for (myopcode=0, i=0; i < opset_len; i++) {
	U16 bits = bitmap[i];
	for (j=0; j < 8 && myopcode < maxo; j++, myopcode++) {
	    if ( bits & (1 << j) )
		XPUSHs(sv_2mortal(newSVpv(names[myopcode], 0)));
	}
    }
    }


void
opset(...)
    CODE:
    int i, j;
    SV *bitspec, *opset;
    char *bitmap;
    STRLEN len, on;
    opset = new_opset(Nullsv);
    bitmap = SvPVX(opset);
    for (i = 0; i < items; i++) {
	char *opname;
	on = 1;
	if (verify_opset(ST(i),0)) {
	    opname = "(opset)";
	    bitspec = ST(i);
	}
	else {
	    opname = SvPV(ST(i), len);
	    if (*opname == '!') { on=0; ++opname;--len; }
	    bitspec = get_op_bitspec(opname, len, 1);
	}
	set_opset_bits(bitmap, bitspec, on, opname);
    }
    ST(0) = opset;


#define PERMITING  (ix == 0 || ix == 1)
#define ONLY_THESE (ix == 0 || ix == 2)

void
permit_only(safe, ...)
    SV *safe
    ALIAS:
	permit    = 1
	deny_only = 2
	deny      = 3
    CODE:
    int i, on;
    SV *bitspec, *mask;
    char *bitmap, *opname;
    STRLEN len;

    if (!SvROK(safe) || !SvOBJECT(SvRV(safe)) || SvTYPE(SvRV(safe))!=SVt_PVHV)
	croak("Not a Safe object");
    mask = *hv_fetch((HV*)SvRV(safe), "Mask",4, 1);
    if (ONLY_THESE)	/* *_only = new mask, else edit current	*/
	 sv_setsv(mask, new_opset(PERMITING ? opset_all : Nullsv));
    else verify_opset(mask,1); /* croaks */
    bitmap = SvPVX(mask);
    for (i = 1; i < items; i++) {
	on = PERMITING ? 0 : 1;		/* deny = mask bit on	*/
	if (verify_opset(ST(i),0)) {	/* it's a valid mask	*/
	    opname = "(opset)";
	    bitspec = ST(i);
	}
	else {				/* it's an opname/optag	*/
	    opname = SvPV(ST(i), len);
	    /* invert if op has ! prefix (only one allowed)	*/
	    if (*opname == '!') { on = !on; ++opname; --len; }
	    bitspec = get_op_bitspec(opname, len, 1); /* croaks */
	}
	set_opset_bits(bitmap, bitspec, on, opname);
    }
    ST(0) = &sv_yes;


void
opdesc(...)
    PPCODE:
    int i, myopcode;
    STRLEN len;
    SV **args;
    /* copy args to a scratch area since we may push output values onto	*/
    /* the stack faster than we read values off it if masks are used.	*/
    args = (SV**)SvPVX(sv_2mortal(newSVpv((char*)&ST(0), items*sizeof(SV*))));
    for (i = 0; i < items; i++) {
	char *opname = SvPV(args[i], len);
	SV *bitspec = get_op_bitspec(opname, len, 1);
	if (SvIOK(bitspec)) {
	    myopcode = SvIV(bitspec);
	    if (myopcode < 0 || myopcode >= maxo)
		croak("panic: opcode %d (%s) out of range",myopcode,opname);
	    XPUSHs(sv_2mortal(newSVpv(op_desc[myopcode], 0)));
	}
	else if (SvPOK(bitspec) && SvCUR(bitspec) == opset_len) {
	    int b, j;
	    char *bitmap = SvPV(bitspec,na);
	    myopcode = 0;
	    for (b=0; b < opset_len; b++) {
		U16 bits = bitmap[b];
		for (j=0; j < 8 && myopcode < maxo; j++, myopcode++)
		    if (bits & (1 << j))
			XPUSHs(sv_2mortal(newSVpv(op_desc[myopcode], 0)));
	    }
	}
	else
	    croak("panic: invalid bitspec for \"%s\" (type %u)",
		opname, (unsigned)SvTYPE(bitspec));
    }


void
define_optag(optagsv, mask)
    SV *optagsv
    SV *mask
    CODE:
    STRLEN len;
    char *optag = SvPV(optagsv, len);
    put_op_bitspec(optag, len, mask); /* croaks */
    ST(0) = &sv_yes;


void
empty_opset()
    CODE:
    ST(0) = sv_2mortal(new_opset(Nullsv));

void
full_opset()
    CODE:
    ST(0) = sv_2mortal(new_opset(opset_all));

void
opmask_add(opset)
    SV *opset
    PREINIT:
    if (!op_mask)
	Newz(0, op_mask, maxo, char);

void
opcodes()
    PPCODE:
    if (GIMME == G_ARRAY) {
	croak("opcodes in list context not yet implemented"); /* XXX */
    }
    else {
	XPUSHs(sv_2mortal(newSViv(maxo)));
    }

void
opmask()
    CODE:
    ST(0) = sv_2mortal(new_opset(Nullsv));
    if (op_mask) {
	char *bitmap = SvPVX(ST(0));
	int myopcode;
	for(myopcode=0; myopcode < maxo; ++myopcode) {
	    if (op_mask[myopcode])
		bitmap[myopcode >> 3] |= 1 << (myopcode & 0x07);
	}
    }
Commit	Line	Data
6badd1a5	1	#include "EXTERN.h"
	2	#include "perl.h"
	3	#include "XSUB.h"
	4
	5	/* maxo shouldn't differ from MAXO but leave room anyway (see BOOT:) */
	6	#define OP_MASK_BUF_SIZE (MAXO + 100)
	7
	8	static HV op_named_bits; / cache shared for whole process */
	9	static SV opset_all; / mask with all bits set */
	10	static IV opset_len; /* length of opmasks in bytes */
	11	static int opcode_debug = 0;
	12
	13	static SV new_opset _((SV old_opset));
	14	static int verify_opset _((SV *opset, int fatal));
	15	static void set_opset_bits _((char bitmap, SV bitspec, int on, char *opname));
	16	static void put_op_bitspec _((char optag, STRLEN len, SV opset));
	17	static SV get_op_bitspec _((char opname, STRLEN len, int fatal));
	18
	19
	20	/* Initialise our private op_named_bits HV.
	21	* It is first loaded with the name and number of each perl operator.
	22	* Then the builtin tags :none and :all are added.
	23	* Opcode.pm loads the standard optags from __DATA__
	24	*/
	25
	26	static void
f0f333f4	27	op_names_init(void)
6badd1a5	28	{
	29	int i;
	30	STRLEN len;
	31	char *opname;
	32	char *bitmap;
	33
	34	op_named_bits = newHV();
	35	for(i=0; i < maxo; ++i) {
e858de61	36	SV *sv;
	37	sv = newSViv(i);
	38	SvREADONLY_on(sv);
	39	hv_store(op_named_bits, op_name[i], strlen(op_name[i]), sv, 0);
6badd1a5	40	}
	41
	42	put_op_bitspec(":none",0, sv_2mortal(new_opset(Nullsv)));
	43
	44	opset_all = new_opset(Nullsv);
	45	bitmap = SvPV(opset_all, len);
	46	i = len-1; /* deal with last byte specially, see below */
	47	while(i-- > 0)
	48	bitmap[i] = 0xFF;
	49	/* Take care to set the right number of bits in the last byte */
8903cb82	50	bitmap[len-1] = (maxo & 0x07) ? ~(0xFF << (maxo & 0x07)) : 0xFF;
6badd1a5	51	put_op_bitspec(":all",0, opset_all); /* don't mortalise */
	52	}
	53
	54
	55	/* Store a new tag definition. Always a mask.
	56	* The tag must not already be defined.
	57	* SV *mask is copied not referenced.
	58	*/
	59
	60	static void
f0f333f4	61	put_op_bitspec(char optag, STRLEN len, SV mask)
6badd1a5	62	{
	63	SV **svp;
	64	verify_opset(mask,1);
	65	if (!len)
	66	len = strlen(optag);
	67	svp = hv_fetch(op_named_bits, optag, len, 1);
	68	if (SvOK(*svp))
	69	croak("Opcode tag \"%s\" already defined", optag);
	70	sv_setsv(*svp, mask);
	71	SvREADONLY_on(*svp);
	72	}
	73
	74
	75
	76	/* Fetch a 'bits' entry for an opname or optag (IV/PV).
	77	* Note that we return the actual entry for speed.
	78	* Always sv_mortalcopy() if returing it to user code.
	79	*/
	80
	81	static SV *
f0f333f4	82	get_op_bitspec(char *opname, STRLEN len, int fatal)
6badd1a5	83	{
	84	SV **svp;
	85	if (!len)
	86	len = strlen(opname);
	87	svp = hv_fetch(op_named_bits, opname, len, 0);
	88	if (!svp \|\| !SvOK(*svp)) {
	89	if (!fatal)
	90	return Nullsv;
	91	if (*opname == ':')
	92	croak("Unknown operator tag \"%s\"", opname);
	93	if (opname == '!') / XXX here later, or elsewhere? */
	94	croak("Can't negate operators here (\"%s\")", opname);
	95	if (isALPHA(*opname))
	96	croak("Unknown operator name \"%s\"", opname);
	97	croak("Unknown operator prefix \"%s\"", opname);
	98	}
	99	return *svp;
	100	}
	101
	102
	103
	104	static SV *
f0f333f4	105	new_opset(SV *old_opset)
6badd1a5	106	{
	107	SV *opset;
	108	if (old_opset) {
	109	verify_opset(old_opset,1);
	110	opset = newSVsv(old_opset);
	111	}
	112	else {
	113	opset = newSV(opset_len);
67a5ea69	114	Zero(SvPVX(opset), opset_len + 1, char);
6badd1a5	115	SvCUR_set(opset, opset_len);
	116	(void)SvPOK_only(opset);
	117	}
	118	/* not mortalised here */
	119	return opset;
	120	}
	121
	122
	123	static int
f0f333f4	124	verify_opset(SV *opset, int fatal)
6badd1a5	125	{
	126	char *err = Nullch;
	127	if (!SvOK(opset)) err = "undefined";
	128	else if (!SvPOK(opset)) err = "wrong type";
	129	else if (SvCUR(opset) != opset_len) err = "wrong size";
	130	if (err && fatal) {
	131	croak("Invalid opset: %s", err);
	132	}
	133	return !err;
	134	}
	135
	136
	137	static void
f0f333f4	138	set_opset_bits(char bitmap, SV bitspec, int on, char *opname)
6badd1a5	139	{
	140	if (SvIOK(bitspec)) {
	141	int myopcode = SvIV(bitspec);
	142	int offset = myopcode >> 3;
	143	int bit = myopcode & 0x07;
	144	if (myopcode >= maxo \|\| myopcode < 0)
	145	croak("panic: opcode \"%s\" value %d is invalid", opname, myopcode);
	146	if (opcode_debug >= 2)
ff0cee69	147	warn("set_opset_bits bit %2d (off=%d, bit=%d) %s %s\n",
6badd1a5	148	myopcode, offset, bit, opname, (on)?"on":"off");
	149	if (on)
	150	bitmap[offset] \|= 1 << bit;
	151	else
	152	bitmap[offset] &= ~(1 << bit);
	153	}
	154	else if (SvPOK(bitspec) && SvCUR(bitspec) == opset_len) {
	155
	156	STRLEN len;
	157	char *specbits = SvPV(bitspec, len);
	158	if (opcode_debug >= 2)
	159	warn("set_opset_bits opset %s %s\n", opname, (on)?"on":"off");
	160	if (on)
	161	while(len-- > 0) bitmap[len] \|= specbits[len];
	162	else
	163	while(len-- > 0) bitmap[len] &= ~specbits[len];
	164	}
	165	else
ff0cee69	166	croak("panic: invalid bitspec for \"%s\" (type %u)",
ff0cee69	167	opname, (unsigned)SvTYPE(bitspec));
6badd1a5	168	}
	169
	170
	171	static void
f0f333f4	172	opmask_add(SV opset) / THE ONLY FUNCTION TO EDIT op_mask ITSELF */
6badd1a5	173	{
	174	int i,j;
	175	char *bitmask;
	176	STRLEN len;
	177	int myopcode = 0;
	178
	179	verify_opset(opset,1); /* croaks on bad opset */
	180
	181	if (!op_mask) /* caller must ensure op_mask exists */
	182	croak("Can't add to uninitialised op_mask");
	183
	184	/* OPCODES ALREADY MASKED ARE NEVER UNMASKED. See opmask_addlocal() */
	185
	186	bitmask = SvPV(opset, len);
	187	for (i=0; i < opset_len; i++) {
	188	U16 bits = bitmask[i];
	189	if (!bits) { /* optimise for sparse masks */
	190	myopcode += 8;
	191	continue;
	192	}
	193	for (j=0; j < 8 && myopcode < maxo; )
	194	op_mask[myopcode++] \|= bits & (1 << j++);
	195	}
	196	}
	197
	198	static void
f0f333f4	199	opmask_addlocal(SV opset, char op_mask_buf) /* Localise op_mask then opmask_add() */
6badd1a5	200	{
	201	char *orig_op_mask = op_mask;
	202	SAVEPPTR(op_mask);
	203	if (opcode_debug >= 2)
	204	SAVEDESTRUCTOR((void()_((void)))warn,"op_mask restored");
	205	op_mask = &op_mask_buf[0];
	206	if (orig_op_mask)
	207	Copy(orig_op_mask, op_mask, maxo, char);
	208	else
	209	Zero(op_mask, maxo, char);
	210	opmask_add(opset);
	211	}
	212
	213
	214
	215	MODULE = Opcode PACKAGE = Opcode
	216
	217	PROTOTYPES: ENABLE
	218
	219	BOOT:
	220	assert(maxo < OP_MASK_BUF_SIZE);
760ac839	221	opset_len = (maxo + 7) / 8;
6badd1a5	222	if (opcode_debug >= 1)
ff0cee69	223	warn("opset_len %ld\n", (long)opset_len);
6badd1a5	224	op_names_init();
	225
	226
	227	void
	228	_safe_call_sv(package, mask, codesv)
	229	char * package
	230	SV * mask
	231	SV * codesv
	232	PPCODE:
	233	char op_mask_buf[OP_MASK_BUF_SIZE];
	234	GV *gv;
	235
	236	ENTER;
	237
	238	opmask_addlocal(mask, op_mask_buf);
	239
	240	save_aptr(&endav);
	241	endav = (AV)sv_2mortal((SV)newAV()); /* ignore END blocks for now */
	242
	243	save_hptr(&defstash); /* save current default stack */
	244	/* the assignment to global defstash changes our sense of 'main' */
	245	defstash = gv_stashpv(package, GV_ADDWARN); /* should exist already */
	246
	247	/* defstash must itself contain a main:: so we'll add that now */
	248	/* take care with the ref counts (was cause of long standing bug) */
	249	/* XXX I'm still not sure if this is right, GV_ADDWARN should warn! */
	250	gv = gv_fetchpv("main::", GV_ADDWARN, SVt_PVHV);
	251	sv_free((SV*)GvHV(gv));
	252	GvHV(gv) = (HV*)SvREFCNT_inc(defstash);
	253
	254	PUSHMARK(sp);
	255	perl_call_sv(codesv, GIMME\|G_EVAL\|G_KEEPERR); /* use callers context */
	256	SPAGAIN; /* for the PUTBACK added by xsubpp */
	257	LEAVE;
	258
	259
	260	int
	261	verify_opset(opset, fatal = 0)
	262	SV *opset
	263	int fatal
	264
	265
	266	void
	267	invert_opset(opset)
	268	SV *opset
	269	CODE:
	270	{
	271	char *bitmap;
	272	STRLEN len = opset_len;
	273	opset = new_opset(opset); /* verify and clone opset */
	274	bitmap = SvPVX(opset);
	275	while(len-- > 0)
	276	bitmap[len] = ~bitmap[len];
	277	/* take care of extra bits beyond maxo in last byte */
8903cb82	278	if (maxo & 07)
8903cb82	279	bitmap[opset_len-1] &= ~(0xFF << (maxo & 0x07));
6badd1a5	280	}
	281	ST(0) = opset;
	282
	283
	284	void
	285	opset_to_ops(opset, desc = 0)
	286	SV *opset
	287	int desc
	288	PPCODE:
	289	{
	290	STRLEN len;
	291	int i, j, myopcode;
	292	char *bitmap = SvPV(opset, len);
	293	char **names = (desc) ? op_desc : op_name;
	294	verify_opset(opset,1);
	295	for (myopcode=0, i=0; i < opset_len; i++) {
	296	U16 bits = bitmap[i];
	297	for (j=0; j < 8 && myopcode < maxo; j++, myopcode++) {
	298	if ( bits & (1 << j) )
	299	XPUSHs(sv_2mortal(newSVpv(names[myopcode], 0)));
	300	}
	301	}
	302	}
	303
	304
	305	void
	306	opset(...)
	307	CODE:
	308	int i, j;
	309	SV bitspec, opset;
	310	char *bitmap;
	311	STRLEN len, on;
	312	opset = new_opset(Nullsv);
	313	bitmap = SvPVX(opset);
	314	for (i = 0; i < items; i++) {
	315	char *opname;
	316	on = 1;
	317	if (verify_opset(ST(i),0)) {
	318	opname = "(opset)";
	319	bitspec = ST(i);
	320	}
	321	else {
	322	opname = SvPV(ST(i), len);
	323	if (*opname == '!') { on=0; ++opname;--len; }
	324	bitspec = get_op_bitspec(opname, len, 1);
	325	}
	326	set_opset_bits(bitmap, bitspec, on, opname);
	327	}
	328	ST(0) = opset;
	329
	330
	331	#define PERMITING (ix == 0 \|\| ix == 1)
	332	#define ONLY_THESE (ix == 0 \|\| ix == 2)
	333
	334	void
	335	permit_only(safe, ...)
	336	SV *safe
	337	ALIAS:
	338	permit = 1
	339	deny_only = 2
	340	deny = 3
	341	CODE:
	342	int i, on;
	343	SV bitspec, mask;
344	char bitmap, opname;
345	STRLEN len;
346
347	if (!SvROK(safe) \|\| !SvOBJECT(SvRV(safe)) \|\| SvTYPE(SvRV(safe))!=SVt_PVHV)
348	croak("Not a Safe object");
349	mask = hv_fetch((HV)SvRV(safe), "Mask",4, 1);
350	if (ONLY_THESE) /* _only = new mask, else edit current /
351	sv_setsv(mask, new_opset(PERMITING ? opset_all : Nullsv));
352	else verify_opset(mask,1); /* croaks */
353	bitmap = SvPVX(mask);
354	for (i = 1; i < items; i++) {
355	on = PERMITING ? 0 : 1; /* deny = mask bit on */
356	if (verify_opset(ST(i),0)) { /* it's a valid mask */
357	opname = "(opset)";
358	bitspec = ST(i);
359	}
360	else { /* it's an opname/optag */
361	opname = SvPV(ST(i), len);
362	/* invert if op has ! prefix (only one allowed) */
363	if (*opname == '!') { on = !on; ++opname; --len; }
364	bitspec = get_op_bitspec(opname, len, 1); /* croaks */
365	}
366	set_opset_bits(bitmap, bitspec, on, opname);
367	}
368	ST(0) = &sv_yes;
369
370
371
372	void
373	opdesc(...)
374	PPCODE:
375	int i, myopcode;
376	STRLEN len;
377	SV **args;
378	/* copy args to a scratch area since we may push output values onto */
379	/* the stack faster than we read values off it if masks are used. */
380	args = (SV*)SvPVX(sv_2mortal(newSVpv((char)&ST(0), itemssizeof(SV))));
381	for (i = 0; i < items; i++) {
382	char *opname = SvPV(args[i], len);
383	SV *bitspec = get_op_bitspec(opname, len, 1);
384	if (SvIOK(bitspec)) {
385	myopcode = SvIV(bitspec);
386	if (myopcode < 0 \|\| myopcode >= maxo)
387	croak("panic: opcode %d (%s) out of range",myopcode,opname);
388	XPUSHs(sv_2mortal(newSVpv(op_desc[myopcode], 0)));
389	}
390	else if (SvPOK(bitspec) && SvCUR(bitspec) == opset_len) {
391	int b, j;
392	char *bitmap = SvPV(bitspec,na);
393	myopcode = 0;
394	for (b=0; b < opset_len; b++) {
395	U16 bits = bitmap[b];
396	for (j=0; j < 8 && myopcode < maxo; j++, myopcode++)
397	if (bits & (1 << j))
398	XPUSHs(sv_2mortal(newSVpv(op_desc[myopcode], 0)));
399	}
400	}
401	else
ff0cee69	402	croak("panic: invalid bitspec for \"%s\" (type %u)",
ff0cee69	403	opname, (unsigned)SvTYPE(bitspec));
6badd1a5	404	}
	405
	406
	407	void
	408	define_optag(optagsv, mask)
	409	SV *optagsv
	410	SV *mask
	411	CODE:
	412	STRLEN len;
	413	char *optag = SvPV(optagsv, len);
	414	put_op_bitspec(optag, len, mask); /* croaks */
	415	ST(0) = &sv_yes;
	416
	417
	418	void
	419	empty_opset()
	420	CODE:
	421	ST(0) = sv_2mortal(new_opset(Nullsv));
	422
	423	void
	424	full_opset()
	425	CODE:
	426	ST(0) = sv_2mortal(new_opset(opset_all));
	427
	428	void
	429	opmask_add(opset)
	430	SV *opset
	431	PREINIT:
	432	if (!op_mask)
	433	Newz(0, op_mask, maxo, char);
	434
	435	void
	436	opcodes()
	437	PPCODE:
	438	if (GIMME == G_ARRAY) {
	439	croak("opcodes in list context not yet implemented"); /* XXX */
	440	}
	441	else {
	442	XPUSHs(sv_2mortal(newSViv(maxo)));
	443	}
	444
	445	void
	446	opmask()
	447	CODE:
	448	ST(0) = sv_2mortal(new_opset(Nullsv));
	449	if (op_mask) {
	450	char *bitmap = SvPVX(ST(0));
	451	int myopcode;
	452	for(myopcode=0; myopcode < maxo; ++myopcode) {
	453	if (op_mask[myopcode])
	454	bitmap[myopcode >> 3] \|= 1 << (myopcode & 0x07);
	455	}
	456	}
	457