C++ bn_check函数代码示例

void
split_number(const struct number *n, BIGNUM *i, BIGNUM *f)
{
	u_long rem;

	bn_checkp(BN_copy(i, n->number));

	if (n->scale == 0 && f != NULL)
		BN_zero(f);
	else if (n->scale < sizeof(factors)/sizeof(factors[0])) {
		rem = BN_div_word(i, factors[n->scale]);
		if (f != NULL)
			BN_set_word(f, rem);
	} else {
		BIGNUM *a, *p;
		BN_CTX *ctx;

		a = BN_new();
		bn_checkp(a);
		p = BN_new();
		bn_checkp(p);
		ctx = BN_CTX_new();
		bn_checkp(ctx);

		bn_check(BN_set_word(a, 10));
		bn_check(BN_set_word(p, n->scale));
		bn_check(BN_exp(a, a, p, ctx));
		bn_check(BN_div(i, f, n->number, a, ctx));
		BN_CTX_free(ctx);
		BN_free(a);
		BN_free(p);
	}
}

static void
num_digits(void)
{
	struct number *n = NULL;
	struct value *value;
	size_t digits;

	value = pop();
	if (value != NULL) {
		switch (value->type) {
		case BCODE_NONE:
			return;
		case BCODE_NUMBER:
			digits = count_digits(value->u.num);
			n = new_number();
			bn_check(BN_set_word(n->number, digits));
			break;
		case BCODE_STRING:
			digits = strlen(value->u.string);
			n = new_number();
			bn_check(BN_set_word(n->number, digits));
			break;
		}
		stack_free_value(value);
		push_number(n);
	}
}

static void
bdivmod(void)
{
	struct number *a, *b, *frac, *quotient, *rdiv, *remainder;
	BN_CTX *ctx;
	u_int scale;

	a = pop_number();
	if (a == NULL)
		return;
	b = pop_number();
	if (b == NULL) {
		push_number(a);
		return;
	}

	rdiv = new_number();
	quotient = new_number();
	remainder = new_number();
	scale = max(a->scale, b->scale);
	rdiv->scale = 0;
	remainder->scale = scale;
	quotient->scale = bmachine.scale;
	scale = max(a->scale, b->scale);

	if (BN_is_zero(a->number))
		warnx("divide by zero");
	else {
		normalize(a, scale);
		normalize(b, scale);

		ctx = BN_CTX_new();
		bn_checkp(ctx);
		/*
		 * Unlike other languages' divmod operations, dc is specified
		 * to return the remainder and the full quotient, rather than
		 * the remainder and the floored quotient.  bn(3) has no
		 * function to calculate both.  So we'll use BN_div to get the
		 * remainder and floored quotient, then calculate the full
		 * quotient from those.
		 *
		 * quotient = rdiv + remainder / divisor
		 */
		bn_check(BN_div(rdiv->number, remainder->number,
		    b->number, a->number, ctx));
		frac = div_number(remainder, a, bmachine.scale);
		normalize(rdiv, bmachine.scale);
		normalize(remainder, scale);
		bn_check(BN_add(quotient->number, rdiv->number, frac->number));
		free_number(frac);
		BN_CTX_free(ctx);
	}
	push_number(quotient);
	push_number(remainder);
	free_number(rdiv);
	free_number(a);
	free_number(b);
}

struct number *
readnumber(struct source *src, u_int base)
{
	struct number	*n;
	int		ch;
	bool		sign = false;
	bool		dot = false;
	BN_ULONG	v;
	u_int		i;

	n = new_number();
	bn_check(BN_zero(n->number));

	while ((ch = (*src->vtable->readchar)(src)) != EOF) {

		if ('0' <= ch && ch <= '9')
			v = ch - '0';
		else if ('A' <= ch && ch <= 'F')
			v = ch - 'A' + 10;
		else if (ch == '_') {
			sign = true;
			continue;
		} else if (ch == '.') {
			if (dot)
				break;
			dot = true;
			continue;
		} else {
			(*src->vtable->unreadchar)(src);
			break;
		}
		if (dot)
			n->scale++;

		bn_check(BN_mul_word(n->number, base));

#if 0
		/* work around a bug in BN_add_word: 0 += 0 is buggy.... */
		if (v > 0)
#endif
			bn_check(BN_add_word(n->number, v));
	}
	if (base != 10) {
		scale_number(n->number, n->scale);
		for (i = 0; i < n->scale; i++)
			(void)BN_div_word(n->number, base);
	}
	if (sign)
		negate(n);
	return n;
}

static void
bmod(void)
{
	struct number *a, *b, *r;
	BN_CTX *ctx;
	u_int scale;

	a = pop_number();
	if (a == NULL)
		return;
	b = pop_number();
	if (b == NULL) {
		push_number(a);
		return;
	}

	r = new_number();
	scale = max(a->scale, b->scale);
	r->scale = scale;

	if (BN_is_zero(a->number))
		warnx("remainder by zero");
	else {
		normalize(a, scale);
		normalize(b, scale);

		ctx = BN_CTX_new();
		bn_checkp(ctx);
		bn_check(BN_mod(r->number, b->number, a->number, ctx));
		BN_CTX_free(ctx);
	}
	push_number(r);
	free_number(a);
	free_number(b);
}

static void
load_array(void)
{
	int			reg;
	struct number		*inumber, *n;
	u_long			index;
	struct stack		*stack;
	struct value		*v, copy;

	reg = readreg();
	if (reg >= 0) {
		inumber = pop_number();
		if (inumber == NULL)
			return;
		index = get_ulong(inumber);
		if (BN_cmp(inumber->number, &zero) < 0)
			warnx("negative index");
		else if (index == BN_MASK2 || index > MAX_ARRAY_INDEX)
			warnx("index too big");
		else {
			stack = &bmachine.reg[reg];
			v = frame_retrieve(stack, index);
			if (v == NULL) {
				n = new_number();
				bn_check(BN_zero(n->number));
				push_number(n);
			}
			else
				push(stack_dup_value(v, &copy));
		}
		free_number(inumber);
	}
}

static void
push_scale(void)
{
	struct value	*value;
	u_int		scale = 0;
	struct number	*n;


	value = pop();
	if (value != NULL) {
		switch (value->type) {
		case BCODE_NONE:
			return;
		case BCODE_NUMBER:
			scale = value->u.num->scale;
			break;
		case BCODE_STRING:
			break;
		}
		stack_free_value(value);
		n = new_number();
		bn_check(BN_set_word(n->number, scale));
		push_number(n);
	}
}

static void
to_ascii(void)
{
	struct number *n;
	struct value *value;
	char str[2];

	value = pop();
	if (value != NULL) {
		str[1] = '\0';
		switch (value->type) {
		case BCODE_NONE:
			return;
		case BCODE_NUMBER:
			n = value->u.num;
			normalize(n, 0);
			if (BN_num_bits(n->number) > 8)
				bn_check(BN_mask_bits(n->number, 8));
			str[0] = (char)BN_get_word(n->number);
			break;
		case BCODE_STRING:
			str[0] = value->u.string[0];
			break;
		}
		stack_free_value(value);
		push_string(bstrdup(str));
	}
}

static void
load_array(void)
{
	struct number *inumber, *n;
	struct stack *stack;
	struct value *v;
	struct value copy;
	u_long idx;
	int reg;

	reg = readreg();
	if (reg >= 0) {
		inumber = pop_number();
		if (inumber == NULL)
			return;
		idx = get_ulong(inumber);
		if (BN_is_negative(inumber->number))
			warnx("negative idx");
		else if (idx == ULONG_MAX || idx > MAX_ARRAY_INDEX)
			warnx("idx too big");
		else {
			stack = &bmachine.reg[reg];
			v = frame_retrieve(stack, idx);
			if (v == NULL || v->type == BCODE_NONE) {
				n = new_number();
				bn_check(BN_zero(n->number));
				push_number(n);
			}
			else
				push(stack_dup_value(v, &copy));
		}
		free_number(inumber);
	}
}

void
init_bmachine(bool extended_registers)
{
	int i;

	bmachine.extended_regs = extended_registers;
	bmachine.reg_array_size = bmachine.extended_regs ?
	    REG_ARRAY_SIZE_BIG : REG_ARRAY_SIZE_SMALL;

	bmachine.reg = calloc(bmachine.reg_array_size,
	    sizeof(bmachine.reg[0]));
	if (bmachine.reg == NULL)
		err(1, NULL);

	for (i = 0; i < UCHAR_MAX; i++)
		jump_table[i] = unknown;
	for (i = 0; i < JUMP_TABLE_DATA_SIZE; i++)
		jump_table[jump_table_data[i].ch] = jump_table_data[i].f;

	stack_init(&bmachine.stack);

	for (i = 0; i < bmachine.reg_array_size; i++)
		stack_init(&bmachine.reg[i]);

	bmachine.readstack_sz = READSTACK_SIZE;
	bmachine.readstack = calloc(sizeof(struct source),
	    bmachine.readstack_sz);
	if (bmachine.readstack == NULL)
		err(1, NULL);
	bmachine.obase = bmachine.ibase = 10;
	BN_init(&zero);
	bn_check(BN_zero(&zero));
	(void)signal(SIGINT, sighandler);
}

static void
bsub(void)
{
	struct number	*a, *b, *r;

	a = pop_number();
	if (a == NULL)
		return;
	b = pop_number();
	if (b == NULL) {
		push_number(a);
		return;
	}

	r = new_number();

	r->scale = max(a->scale, b->scale);
	if (r->scale > a->scale)
		normalize(a, r->scale);
	else if (r->scale > b->scale)
		normalize(b, r->scale);
	bn_check(BN_sub(r->number, b->number, a->number));
	push_number(r);
	free_number(a);
	free_number(b);
}

static void
bsqrt(void)
{
	struct number	*n;
	struct number	*r;
	BIGNUM		*x, *y;
	u_int		scale, onecount;
	BN_CTX		*ctx;

	onecount = 0;
	n = pop_number();
	if (n == NULL) {
		return;
	}
	if (BN_is_zero(n->number)) {
		r = new_number();
		push_number(r);
	} else if (BN_is_negative(n->number))
		warnx("square root of negative number");
	else {
		scale = max(bmachine.scale, n->scale);
		normalize(n, 2*scale);
		x = BN_dup(n->number);
		bn_checkp(x);
		bn_check(BN_rshift(x, x, BN_num_bits(x)/2));
		y = BN_new();
		bn_checkp(y);
		ctx = BN_CTX_new();
		bn_checkp(ctx);
		for (;;) {
			bn_checkp(BN_copy(y, x));
			bn_check(BN_div(x, NULL, n->number, x, ctx));
			bn_check(BN_add(x, x, y));
			bn_check(BN_rshift1(x, x));
			if (bsqrt_stop(x, y, &onecount))
				break;
		}
		r = bmalloc(sizeof(*r));
		r->scale = scale;
		r->number = y;
		BN_free(x);
		BN_CTX_free(ctx);
		push_number(r);
	}

	free_number(n);
}

static void
get_ibase(void)
{
	struct number *n;

	n = new_number();
	bn_check(BN_set_word(n->number, bmachine.ibase));
	push_number(n);
}

static void
stackdepth(void)
{
	struct number *n;
	size_t i;

	i = stack_size(&bmachine.stack);
	n = new_number();
	bn_check(BN_set_word(n->number, i));
	push_number(n);
}

static void
not(void)
{
	struct number *a;

	a = pop_number();
	if (a == NULL)
		return;
	a->scale = 0;
	bn_check(BN_set_word(a->number, BN_get_word(a->number) ? 0 : 1));
	push_number(a);
}