<AWT Dev> <Swing Dev> RFR(XXS): 8163408: Fix wrong prototype of getNativeScaleFactor() in systemScale.h

[Alexander Scherbatiy]

The fix should be reviewed on the awt-dev alias.

On 08/08/16 22:36, Volker Simonis wrote:
> Hi,
>
> can I please have a review for the following trivial fix:
>
> http://cr.openjdk.java.net/~simonis/webrevs/2016/8163408/
> https://bugs.openjdk.java.net/browse/JDK-8163408
>
> I'd like to push this directly to jdk9/dev if possible because the
> problem has already spread across all the other repos and I'd like to
> fix it as fast as possible in all repos.
>
> The fix for "8149115: [hidpi] Linux: display-wise scaling factor
> should probably be taken into account" changed the prototype for
> getNativeScaleFactor() in systemScale.h from:
>
> int getNativeScaleFactor();
>
> to
>
> double getNativeScaleFactor();
>
> But forgot to add the "char*" parameter to the signature which is
> required by the implementation in systemScale.c (and the various call
> sites):
>
> double getNativeScaleFactor(char *output_name) {
>
> This leads to the following waring/error:
>
> /OpenJDK/jdk9-hs-comp-s390x/jdk/src/java.desktop/unix/native/libawt_xawt/awt/awt_GraphicsEnv.c:
> In function ‘Ja
> va_sun_awt_X11GraphicsDevice_getNativeScaleFactor’:
> /OpenJDK/jdk9-hs-comp-s390x/jdk/src/java.desktop/unix/native/libawt_xawt/awt/awt_GraphicsEnv.c:2185:5:
> error: c
> all to function ‘getNativeScaleFactor’ without a real prototype
> [-Werror=unprototyped-calls]
>       double scale = getNativeScaleFactor(name);
>       ^
> In file included from
> /OpenJDK/jdk9-hs-comp-s390x/jdk/src/java.desktop/unix/native/libawt_xawt/awt/awt_Graphics
> Env.c:46:0:
> /OpenJDK/jdk9-hs-comp-s390x/jdk/src/java.desktop/unix/native/common/awt/systemscale/systemScale.h:29:8:
> note: ‘
> getNativeScaleFactor’ was declared here
>   double getNativeScaleFactor();
>          ^
> cc1: all warnings being treated as errors
>
> If we fix that we will get:
>
> /usr/work/d046063/OpenJDK/jdk9-hs-comp-s390x/jdk/src/java.desktop/unix/native/libsplashscreen/splashscreen_sys.c:
> In function ‘S
> plashGetScaledImageName’:
> /usr/work/d046063/OpenJDK/jdk9-hs-comp-s390x/jdk/src/java.desktop/unix/native/libsplashscreen/splashscreen_sys.c:809:5:
> error: t
> oo few arguments to function ‘getNativeScaleFactor’
>       *scaleFactor = getNativeScaleFactor();
>       ^
>
> I observed these warnings/errors with 4.8.5 and it is a miracle for me
> why newer versions of GCC (apparently 4.9.2 which seems to be Oracles
> officially supported compiler according to
> https://wiki.openjdk.java.net/display/Build/Supported+Build+Platforms)
> or gcc 5.4.0 whiohc I've tried on Ubuntu 16.04 don't detect this
> problem?
>
> Thank you and best regards,
> Volker