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author | Michael Forney <mforney@mforney.org> | 2019-06-07 11:29:01 -0700 |
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committer | Henrik Rydberg <rydberg@bitmath.se> | 2020-01-26 15:00:32 +0100 |
commit | 5a260fa95a5e7cebdd8f9da947c8d8eb244efae0 (patch) | |
tree | cb6d4cdee41466c790a4ba93ca480d82f942b4b8 | |
parent | 5f9caa26b81155feede6ff71c9b14fa0e8980fbd (diff) | |
download | mtdev-git-5a260fa95a5e7cebdd8f9da947c8d8eb244efae0.tar.gz |
Use a macro for `nlongs` so it can be used in constant expression
This way, it can be used to specify the `absbits` array size (in
`mtdev_configure`) without making it a VLA.
VLAs are an optional feature in C11, and in this case we can determine
the array size statically.
This also matches the macros used in libevdev and libinput.
Signed-off-by: Michael Forney <mforney@mforney.org>
Signed-off-by: Henrik Rydberg <rydberg@bitmath.se>
-rw-r--r-- | src/caps.c | 12 |
1 files changed, 4 insertions, 8 deletions
@@ -32,16 +32,12 @@ static const int SN_COORD = 250; /* coordinate signal-to-noise ratio */ static const int SN_WIDTH = 100; /* width signal-to-noise ratio */ static const int SN_ORIENT = 10; /* orientation signal-to-noise ratio */ -static const int bits_per_long = 8 * sizeof(long); - -static inline int nlongs(int nbit) -{ - return (nbit + bits_per_long - 1) / bits_per_long; -} +#define LONG_BITS (sizeof(long) * 8) +#define NLONGS(x) (((x) + LONG_BITS - 1) / LONG_BITS) static inline int getbit(const unsigned long *map, int key) { - return (map[key / bits_per_long] >> (key % bits_per_long)) & 0x01; + return (map[key / LONG_BITS] >> (key % LONG_BITS)) & 0x01; } static int getabs(struct input_absinfo *abs, int key, int fd) @@ -106,7 +102,7 @@ static int mtdev_set_slots(struct mtdev *dev, int fd) int mtdev_configure(struct mtdev *dev, int fd) { - unsigned long absbits[nlongs(ABS_MAX)]; + unsigned long absbits[NLONGS(ABS_MAX)]; int rc, i; SYSCALL(rc = ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(absbits)), absbits)); |