Support LT_PREREQ as the new alternative of AC_PROG_LIBTOOL. If
the latter is used, show a message with information how to switch
to LT_PREREQ.

Mike Massonnet authored 13 years ago and Nick Schermer committed 13 years ago

The translations have been removed from the code -- Nick.

Use the macro shipped with pkg-config for detection of
$PKG_CONFIG. This to fix cross-build compatibility.

signal.h has an inline that redeclares __errno.

This breaks the sun studio compiler and since -g defaults
to level 2, it provides enough backtrace information.

The FreeBSD bot has some problems with this flag. Disable
it on non-linux systems, since it's not that important.

/bin/sh does not support the -n option for echo. Use printf instead,
which is independent of the shell.

This adds an extra check when XDT_AUTOGEN_CHECK_DOCS
is defined. This variable points to the directory that
should contain the xfce4-docs submodule.

If no submodule clone if found and autogen.sh is running
from within a git clone, it will automatically initialize
the submodule for the user, if not it will show an error
and abort xdt-autogen, since configure will abort too if
we continue because of missing makefile.am files.

This reverts commit 77d9703d.

Only use XDT_FEATURE_VISIBILITY to detect if visibility is
supported by the compiler. Setting the default visibility
to hidden will break libraries and modules that don't
set the visibility of their public function to "default".

also make the non-defaults explicit and therefore less confusing (it
worked before due to default autoconf shell-ification of the first arg,
but that's not immediately clear)

This reverts commit 90d68641.

AC_ARG_ENABLE executes the code its last parameter if the --enable flag
is not provided, not if the --disable flag is not provided. That's why
we need to set the value to "no", not to "yes".

Also don't show the --disable-debug option (with weird indentation)
because the help message already explains that there are --disable
variants for all --enable options.

This uses the m4_default() macro instead of the custom code to check
which debug level should be used as the default. $default_level was
not set when running configure with --help before.

It seems we also need to use [enable_debug=$enableval] in
AC_ARG_ENABLE() for enable_debug to be set. Tested it and it works fine.