makepkg: Add support for Fortran build flags

Signed-off-by: Allan McRae <allan@archlinux.org>

etc/makepkg.conf.d/fortran.conf.in

@@ -0,0 +1,18 @@
+#!/hint/bash
+#
+# @sysconfdir@/makepkg.conf.d/fortran.conf
+#
+
+#########################################################################
+# FORTRAN LANGUAGE SUPPORT
+#########################################################################
+
+# Flags used for the Fortran compiler, similar in spirit to CFLAGS. Read
+# linkman:gfortran[1] for more details on the available flags.
+#FFLAGS="-O2 -pipe"
+#FCFLAGS="$FFLAGS"
+
+# Additional compiler flags appended to `FFLAGS` and `FCFLAGS` for use in debugging. Usually
+# this would include: ``-g''. Read linkman:gfortran[1] for more details on the wide
+# variety of compiler flags available.
+#DEBUG_FFLAGS="-g"

meson.build

@@ -420,6 +420,12 @@ configure_file(
   configuration : substs,
   install_dir : SYSCONFDIR)
 
+configure_file(
+  input : 'etc/makepkg.conf.d/fortran.conf.in',
+  output : 'fortran.conf',
+  configuration : substs,
+  install_dir : join_paths(SYSCONFDIR, 'makepkg.conf.d/'))
+
 configure_file(
   input : 'etc/makepkg.conf.d/rust.conf.in',
   output : 'rust.conf',

scripts/libmakepkg/buildenv/fortran.sh.in

@@ -0,0 +1,38 @@
+#!/usr/bin/bash
+#
+#   fortran.sh - Specify flags for building a package with Fortran
+#
+#   Copyright (c) 2024 Pacman Development Team <pacman-dev@lists.archlinux.org>
+#
+#   This program is free software; you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation; either version 2 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+[[ -n "$LIBMAKEPKG_BUILDENV_FORTRAN_SH" ]] && return
+LIBMAKEPKG_BUILDENV_FORTRAN_SH=1
+
+MAKEPKG_LIBRARY=${MAKEPKG_LIBRARY:-'@libmakepkgdir@'}
+
+source "$MAKEPKG_LIBRARY/util/option.sh"
+source "$MAKEPKG_LIBRARY/util/util.sh"
+
+buildenv_vars+=('FFLAGS' 'FCFLAGS' 'DEBUG_FFLAGS')
+buildenv_functions+=('buildenv_fortran')
+
+buildenv_fortran() {
+	if check_option "debug" "y" && ! check_option "buildflags" "n"; then
+		append_once DEBUG_FFLAGS "-ffile-prefix-map=$srcdir=${DBGSRCDIR:-/usr/src/debug}/${pkgbase}"
+		append_once FFLAGS "$DEBUG_FFLAGS"
+		append_once FCFLAGS "$DEBUG_FFLAGS"
+	fi
+}