Upon re-reading the autoconf documentation, this seemed the right thing
to do. The AC_LANG_PROGRAM macro does not quote its arguments so any
occurence of [ and ] will get stripped out if not double quoted.
Current code snippets passed do not use them but it is better to use a
consistent quoting approach for such snippets. In other places in the
configure.ac file double quoting is used already.
This gets rid of a number of obsoleted macros and replaces RETSIGTYPE
with a void literal which can be assumed for C89 and later.
This changeset was prepared using autoupdate and modified to get rid of
whitespace and doubled [] changes. Changes to acinclude.m4 were added
by hand.
Several variables are considered "user variables" by the GNU Standards.
This means that the user can pass these to their ./configure and make
invocations as they see fit. These variables include CPPFLAGS, CFLAGS
and LDFLAGS.
This changeset pushes our use of these variables to the automake shadow
variables, AM_CPPFLAGS, AM_CFLAGS and AM_LDFLAGS, so that user variables
will no longer clobber flags required in order to build.
This addresses autoreconf output such as:
tools/Makefile.am:37: warning: source file '../backend/sane_strstatus.c' is in a subdirectory,
tools/Makefile.am:37: but option 'subdir-objects' is disabled
The option was introduced in automake version 1.9 and is slated for
unconditional activation with automake-2.0.
This name has been preferred since autoconf-2.52 and automake-1.5.
Both were released in the summer of 2001. Support for configure.in
is slated for removal in automake-2.0.
The configure.ac file itself requires autoconf-2.54 or later (and
does not care about the automake version).
Olaf Meeuwissen