8. Bootstrapping

There are many programs in the GNU Autotools, each of which has a complex set of inputs. When one of these inputs changes, it is important to run the proper programs in the proper order. Unfortunately, it is hard to remember both the dependencies and the ordering.

For instance, whenever you edit `configure.in', you must remember to re-run aclocal in case you added a reference to a new macro. You must also rebuild `configure' by running autoconf; `config.h' by running autoheader, in case you added a new AC_DEFINE; and automake to propagate any new AC_SUBSTs to the various `Makefile.in's. If you edit a `Makefile.am', you must re-run automake. In both these cases, you must then remember to re-run config.status --recheck if `configure' changed, followed by config.status to rebuild the `Makefile's.

When doing active development on the build system for your project, these dependencies quickly become painful.

#!/bin/sh
# you can either set the environment variables AUTOCONF and AUTOMAKE
# to the right versions, or leave them unset and get the RedHat 7.3 defaults

DIE=0
package=gst-plugin
srcfile=src/main.c

# autogen.sh helper functions (copied from GStreamer's common/ CVS module)
if test ! -f ./gst-autogen.sh;
then
  echo There is something wrong with your source tree.
  echo You are either missing ./gst-autogen.sh or not
  echo running autogen.sh from the top-level source
  echo directory.
  exit 1
fi
. ./gst-autogen.sh

CONFIGURE_DEF_OPT='--enable-maintainer-mode --enable-debug'

autogen_options $@

echo -n "+ check for build tools"
if test ! -z "$NOCHECK"; then echo " skipped"; else  echo; fi
version_check "autoconf" "$AUTOCONF autoconf autoconf259 autoconf257 autoconf-2.54 autoconf-2.53 autoconf-2.52" \
              "ftp://ftp.gnu.org/pub/gnu/autoconf/" 2 52 || DIE=1
version_check "automake" "$AUTOMAKE automake automake-1.9 automake19 automake-1.7 automake-1.6 automake-1.5" \
              "ftp://ftp.gnu.org/pub/gnu/automake/" 1 7 || DIE=1
###version_check "autopoint" "autopoint" \
###              "ftp://ftp.gnu.org/pub/gnu/gettext/" 0 11 5 || DIE=1
version_check "libtoolize" "$LIBTOOLIZE libtoolize glibtoolize" \
              "ftp://ftp.gnu.org/pub/gnu/libtool/" 1 5 0 || DIE=1
version_check "pkg-config" "" \
              "http://www.freedesktop.org/software/pkgconfig" 0 8 0 || DIE=1

die_check $DIE

autoconf_2_52d_check || DIE=1
aclocal_check || DIE=1
autoheader_check || DIE=1

die_check $DIE

# if no arguments specified then this will be printed
if test -z "$*"; then
  echo "+ checking for autogen.sh options"
  echo "  This autogen script will automatically run ./configure as:"
  echo "  ./configure $CONFIGURE_DEF_OPT"
  echo "  To pass any additional options, please specify them on the $0"
  echo "  command line."
fi

tool_run "$aclocal" "-I m4/ $ACLOCAL_FLAGS"
tool_run "$libtoolize" "--copy --force"
tool_run "$autoheader"
tool_run "$autoconf"
tool_run "$automake" "-a -c"

# if enable exists, add an -enable option for each of the lines in that file
if test -f enable; then
  for a in `cat enable`; do
    CONFIGURE_FILE_OPT="--enable-$a"
  done
fi

# if disable exists, add an -disable option for each of the lines in that file
if test -f disable; then
  for a in `cat disable`; do
    CONFIGURE_FILE_OPT="$CONFIGURE_FILE_OPT --disable-$a"
  done
fi

test -n "$NOCONFIGURE" && {
  echo "+ skipping configure stage for package $package, as requested."
  echo "+ autogen.sh done."
  exit 0
}

echo "+ running configure ... "
test ! -z "$CONFIGURE_DEF_OPT" && echo "  ./configure default flags: $CONFIGURE_DEF_OPT"
test ! -z "$CONFIGURE_EXT_OPT" && echo "  ./configure external flags: $CONFIGURE_EXT_OPT"
test ! -z "$CONFIGURE_FILE_OPT" && echo "  ./configure enable/disable flags: $CONFIGURE_FILE_OPT"
echo

./configure $CONFIGURE_DEF_OPT $CONFIGURE_EXT_OPT $CONFIGURE_FILE_OPT || {
        echo "  configure failed"
        exit 1
}

echo "Now type 'make' to compile $package."