[PATCH xf86-input-libinput 1/3] Add streq() macro, replace strcmp instances with it

[Peter Hutterer]

On Fri, Feb 24, 2017 at 02:31:55PM +0000, Eric Engestrom wrote:
> On Friday, 2017-02-24 14:13:39 +0000, Eric Engestrom wrote:
> > On Friday, 2017-02-24 13:10:17 +1000, Peter Hutterer wrote:
> > > And why isn't this a thing in glibc yet
> > 
> > Indeed :(
> > So many bugs caused by someone assuming `if (strcmp(a, b))` means a==b...
> > 
> > > 
> > > Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> > > ---
> > >  src/xf86libinput.c | 21 ++++++++++++---------
> > >  1 file changed, 12 insertions(+), 9 deletions(-)
> > > 
> > > diff --git a/src/xf86libinput.c b/src/xf86libinput.c
> > > index 703d872..c1214b7 100644
> > > --- a/src/xf86libinput.c
> > > +++ b/src/xf86libinput.c
> > > @@ -65,6 +65,9 @@
> > >  #define TOUCH_MAX_SLOTS 15
> > >  #define XORG_KEYCODE_OFFSET 8
> > >  
> > > +#define streq(a, b) (strcmp(a, b) == 0)
> > > +#define strneq(a, b, n) (strncmp(a, b, n) == 0)
> > 
> > strneq() reads to me as "string not equal"...
> > streqn() might be a better name?
> 
> Actually, strneq() seems to be already used in a few places, like
> systemd [1] or the kernel's dtc script [2], whereas streqn() doesn't
> seem to be used much anywhere.
> 
> Feel free to ignore my previous message and keep the name :)

heh, I think I will ;)

fwiw, we already use streq and strneq in libinput as well, so I'd like to
keep those the same. and there's the strcmp -> strncmp similarity.
Thanks for the review!

Cheers,
   Peter


> 
> [1] https://github.com/systemd/systemd/blob/master/src/basic/string-util.h#L43
> [2] http://lxr.free-electrons.com/source/scripts/dtc/dtc.h#L66
> 
> > 
> > And a bit of a nitpick, but could you move its introduction to the patch
> > that starts using it (ie. 3/3)?
> > 
> > Otherwise, this patch is:
> > Reviewed-by: Eric Engestrom <eric.engestrom at imgtec.com>
> > 
> > (the other patches require more knowledge than I have)
> > 
> > > +
> > >  /*
> > >     libinput does not provide axis information for absolute devices, instead
> > >     it scales into the screen dimensions provided. So we set up the axes with
> > > @@ -259,7 +262,7 @@ xf86libinput_is_subdevice(InputInfoPtr pInfo)
> > >  	BOOL is_subdevice;
> > >  
> > >  	source = xf86SetStrOption(pInfo->options, "_source", "");
> > > -	is_subdevice = strcmp(source, "_driver/libinput") == 0;
> > > +	is_subdevice = streq(source, "_driver/libinput");
> > >  	free(source);
> > >  
> > >  	return is_subdevice;
> > > @@ -1213,7 +1216,7 @@ is_libinput_device(InputInfoPtr pInfo)
> > >  	BOOL rc;
> > >  
> > >  	driver = xf86CheckStrOption(pInfo->options, "driver", "");
> > > -	rc = strcmp(driver, "libinput") == 0;
> > > +	rc = streq(driver, "libinput");
> > >  	free(driver);
> > >  
> > >  	return rc;
> > > @@ -2187,7 +2190,7 @@ open_restricted(const char *path, int flags, void *data)
> > >  	nt_list_for_each_entry(pInfo, xf86FirstLocalDevice(), next) {
> > >  		char *device = xf86CheckStrOption(pInfo->options, "Device", NULL);
> > >  
> > > -		if (device != NULL && strcmp(path, device) == 0) {
> > > +		if (device != NULL && streq(path, device)) {
> > >  			free(device);
> > >  			break;
> > >  		}
> > > @@ -2353,9 +2356,9 @@ xf86libinput_parse_tap_buttonmap_option(InputInfoPtr pInfo,
> > >  			       "TappingButtonMap",
> > >  			       NULL);
> > >  	if (str) {
> > > -		if (strcmp(str, "lmr") == 0)
> > > +		if (streq(str, "lmr"))
> > >  			map = LIBINPUT_CONFIG_TAP_MAP_LMR;
> > > -		else if (strcmp(str, "lrm") == 0)
> > > +		else if (streq(str, "lrm"))
> > >  			map = LIBINPUT_CONFIG_TAP_MAP_LRM;
> > >  		else
> > >  			xf86IDrvMsg(pInfo, X_ERROR,
> > > @@ -2468,11 +2471,11 @@ xf86libinput_parse_sendevents_option(InputInfoPtr pInfo,
> > >  				   "SendEventsMode",
> > >  				   NULL);
> > >  	if (modestr) {
> > > -		if (strcmp(modestr, "enabled") == 0)
> > > +		if (streq(modestr, "enabled"))
> > >  			mode = LIBINPUT_CONFIG_SEND_EVENTS_ENABLED;
> > > -		else if (strcmp(modestr, "disabled") == 0)
> > > +		else if (streq(modestr, "disabled"))
> > >  			mode = LIBINPUT_CONFIG_SEND_EVENTS_DISABLED;
> > > -		else if (strcmp(modestr, "disabled-on-external-mouse") == 0)
> > > +		else if (streq(modestr, "disabled-on-external-mouse"))
> > >  			mode = LIBINPUT_CONFIG_SEND_EVENTS_DISABLED_ON_EXTERNAL_MOUSE;
> > >  		else
> > >  			xf86IDrvMsg(pInfo, X_ERROR,
> > > @@ -2866,7 +2869,7 @@ xf86libinput_parse_tablet_area_option(InputInfoPtr pInfo,
> > >  	str = xf86SetStrOption(pInfo->options,
> > >  			       "TabletToolAreaRatio",
> > >  			       NULL);
> > > -	if (!str || strcmp(str, "default") == 0)
> > > +	if (!str || streq(str, "default"))
> > >  		goto out;
> > >  
> > >  	rc = sscanf(str, "%d:%d", &area.x, &area.y);
> > > -- 
> > > 2.9.3
> > >