Enable silent build rules by default

[ndim]

Enable silent build rules by default.

You can still use verbose build rules by using any of the following
methods:

• run configure with the --disable-silent-rules argument
• run make with the V=1 argument

This hides the compiler command line which makes debugging users'
problems more difficult. To compensate for that, this prints the
build flags separately, but a lot less frequently:

For each part of the build (libgphoto2_port.la, iolibs,
libgphoto2.la, camlibs), if something of that part has been
rebuilt, prints the build flags (_CPPFLAGS, _CFLAGS, _LIBADD,
_LDFLAGS) once.

Always prints the environment variables CPPFLAGS CFLAGS LDADD
LIBADD LDFLAGS once, whether they are the defaults the configure
script sets or given on the make command line.

Not all make recipes have been converted to be completely silent,
but the majority (especially the Automake standard recipes) are
now silent.

[axxel]

If configured with "--enable-silent-rules" (before this PR) I get the following output from a "clean" make -s:

Making all in libgphoto2_port
Making all in po
Making all in libgphoto2_port
Making all in .
++ test -f po/Makevars
+ MAKEVARS_FILE=po/Makevars
++ /usr/bin/sed -n 's/^DOMAIN \{0,\}= \{0,\}//p' po/Makevars
+ MAKEVARS_DOMAIN=libgphoto2_port-12
+ MAKE_TIME_DOMAIN=libgphoto2_port-12
+ echo '  MAKEVARS_DOMAIN=libgphoto2_port-12'
  MAKEVARS_DOMAIN=libgphoto2_port-12
+ echo '  GETTEXT_PACKAGE_LIBGPHOTO2_PORT=libgphoto2_port-12'
  GETTEXT_PACKAGE_LIBGPHOTO2_PORT=libgphoto2_port-12
+ test xlibgphoto2_port-12 = xlibgphoto2_port-12
+ echo 'Good: Matching gettext domain values (libgphoto2_port-12)'
Good: Matching gettext domain values (libgphoto2_port-12)
+ true
Making all in tests
Making all in doc
Dummy target all-local.
Making all in libgphoto2
Making all in camlibs
Making all in .
Making all in canon/doc
Dummy target all-local.
Making all in tests
Making all in examples
Making all in po
Making all in packaging
Making all in generic
Making all in doc
Making all in api
Dummy target all-local.
++ test -f po/Makevars
+ MAKEVARS_FILE=po/Makevars
++ /usr/bin/sed -n 's/^DOMAIN \{0,\}= \{0,\}//p' po/Makevars
+ MAKEVARS_DOMAIN=libgphoto2-6
+ MAKE_TIME_DOMAIN=libgphoto2-6
+ echo '  MAKEVARS_DOMAIN=libgphoto2-6'
  MAKEVARS_DOMAIN=libgphoto2-6
+ echo '  GETTEXT_PACKAGE_LIBGPHOTO2=libgphoto2-6'
  GETTEXT_PACKAGE_LIBGPHOTO2=libgphoto2-6
+ test xlibgphoto2-6 = xlibgphoto2-6
+ echo 'Good: Matching gettext domain values (libgphoto2-6)'
Good: Matching gettext domain values (libgphoto2-6)
+ true

Any idea how to get rid of the two blocks with the '+' lines?

[ndim]

Yes, I have an idea. Should be about fixed. Always prints

make[2]: Entering directory '/home/ndim/src/gphoto/libgphoto2/_b'
  CHECK   Good: Matching gettext domain values (libgphoto2-6)
make[2]: Leaving directory '/home/ndim/src/gphoto/libgphoto2/_b'

now.

[ndim]

Only prints the CHECK message in the silent rules case any more if the check has failed.

[ndim]

Doxygen is still the source of a huge number of warnings, even when run as doxygen -q.

[ndim]

Prints foo_CFLAGS etc now (once only, not for every compiler invocation, and only if foo has actually been rebuilt).

I still want to add CFLAGS etc from the make command line to that output, though.

[ndim]

This should be about done. Any more complaints/suggestions/questions?

[axxel]

I see that the make install call is still very verbose including lots of libtool relinking warnings. I used to see them all the time until I set up few symlinks to the *.so files in my build directory to spare me that part.

[ndim]

@axxel I cannot influence the output of make install.

[ndim]

As far as I can tell, this shows everything from the build flags which I want to see, while still making the output much less verbose/confusing than all the compiler command lines would be.

@msmeissn Are you OK with the reduced output? The build flags are not completely hidden. See the CI build output.

Going forward, some more verbosity could be removed by switching to nonrecursive make on the Automake side, and adressing C compiler warnings on the C code side.

The gtk-doc/doxygen situation and its output is a separate problem.

[msmeissn]

for me it looks good.