xref: /src/tests/usr.bin/xlint/lint1/msg_241.c

/*	$NetBSD: msg_241.c,v 1.6 2021/08/16 20:11:03 rillig Exp $	*/
# 3 "msg_241.c"

// Test for message: dubious operation on enum, op %s [241]
//
// As of February 2021, the option -e is not enabled by default in
// share/mk/sys.mk, therefore this message is neither well-known nor
// well-tested.

/* lint1-extra-flags: -e */

/*
 * Enums are a possible implementation of bit-sets.
 */
enum color {
	RED	= 1 << 0,
	GREEN	= 1 << 1,
	BLUE	= 1 << 2
};

extern void sink_bool(_Bool);
extern void sink_int(int);
extern void sink_color(enum color);

void
example(void)
{
	enum color c = RED;

	sink_bool(!c);		/* expect: 241 */
	sink_color(~c);		/* expect: 241 */
	++c;			/* expect: 241 */
	--c;			/* expect: 241 */
	c++;			/* expect: 241 */
	c--;			/* expect: 241 */
	sink_color(+c);		/* expect: 241 */
	sink_color(-c);		/* expect: 241 */
	sink_color(c * c);	/* expect: 241 */
	sink_color(c / c);	/* expect: 241 */
	sink_color(c % c);	/* expect: 241 */
	sink_color(c + c);	/* expect: 241 */
	sink_color(c - c);	/* expect: 241 */
	sink_color(c << c);	/* expect: 241 */
	sink_color(c >> c);	/* expect: 241 */

	sink_bool(c < c);
	sink_bool(c <= c);
	sink_bool(c > c);
	sink_bool(c >= c);
	sink_bool(c == c);
	sink_bool(c != c);

	sink_color(c & c);	/* expect: 241 */
	sink_color(c ^ c);	/* expect: 241 */
	sink_color(c | c);	/* expect: 241 */

	sink_bool(c && c);	/* expect: 241 */
	sink_bool(c || c);	/* expect: 241 */
	sink_color(c ? c : BLUE);

	c = GREEN;
	c *= c;			/* expect: 241 */
	c /= c;			/* expect: 241 */
	c %= c;			/* expect: 241 */
	c += c;			/* expect: 241 */
	c -= c;			/* expect: 241 */
	c <<= c;		/* expect: 241 */
	c >>= c;		/* expect: 241 */
	c &= c;			/* expect: 241 */
	c ^= c;			/* expect: 241 */
	c |= c;			/* expect: 241 */

	/* The cast to unsigned is required by GCC at WARNS=6. */
	c &= ~(unsigned)GREEN;	/* expect: 241 */
}

void
cover_typeok_enum(enum color c, int i)
{
	/* expect+2: warning: dubious operation on enum, op * [241] */
	/* expect+1: warning: combination of 'enum color' and 'int', op > [242] */
	if (c * i > 5)
		return;
}

const char *
color_name(enum color c)
{
	static const char *name[] = { "red", "green", "blue" };

	if (c == RED)
		return *(c + name); /* unusual but allowed */
	if (c == GREEN)
		return c[name]; /* even more unusual */
	return name[c];
}