Mitigate Debian Trixie/Sid GCC/GNAT version mismatch

When I tested Debian Trixie, and Debian Sid, I saw that
GCC in PATH pointed to gcc-14, but gnat in path pointed
to GNAT-13, even if you manually install gnat-14.

GNAT 14 was marked experimental, but GCC 14 was marked
for use, in the apt repositories.

So this patch doesn't address the mismatch when doing e.g.
apt-get install gcc gnat

I will address the actual package dependency in a follow-up
patch, on the Debian dependencies config.

Signed-off-by: Leah Rowe <leah@libreboot.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/include/path.sh b/include/path.sh
new file mode 100644
index 00000000..04e1d887
--- /dev/null
+++ b/include/path.sh
@@ -0,0 +1,46 @@
+#!/usr/bin/env sh
+# SPDX-License-Identifier: MIT
+# Copyright (c) 2024 Leah Rowe <leah@libreboot.org>
+
+# debian trixie/sid ship with gcc 14 when running "gcc",
+# but (as of December 2024) gnat is gnat-13. we must create
+# a symlink accordingly.
+# however, the user may also have gcc 13+14, but only gnat 13
+check_gnat_path()
+{
+	eval `setvars "" gccver gnatver gccdir`
+	command -v gcc 1>/dev/null || $err "Command 'gcc' unavailable."
+
+	for _util in gcc gnat; do
+		eval "$_util --version 1>/dev/null 2>/dev/null || continue"
+		eval "${_util}ver=\"`$_util --version 2>/dev/null | head -n1`\""
+		eval "${_util}ver=\"\${${_util}ver##* }\""
+		eval "${_util}ver=\"\${${_util}ver%%.*}\""
+	done
+
+	[ -z "$gccver" ] && $err "Cannot detect host GCC version"
+	[ "$gnatver" = "$gccver" ] && return 0
+
+	gccdir="$(dirname "$(command -v gcc)")"
+
+	for _gnatbin in "$gccdir/gnat-"*; do
+		[ -f "$_gnatbin" ] || continue
+		[ "${_gnatbin#"$gccdir/gnat-"}" = "$gccver" ] || continue
+		gnatver="${_gnatbin#"$gccdir/gnat-"}"
+		break
+	done
+
+	[ "$gnatver" = "$gccver" ] || $err "GCC/GNAT versions do not match."
+
+	# we already established that the versions match, but if gnat isn't
+	# in path, then we assume it's in e.g. /usr/bin/gnat-14
+	(
+	x_ cd xbmkpath
+	for _gnatbin in "$gccdir/gnat"*"-$gccver"; do
+		[ -e "$_gnatbin" ] || continue
+		_gnatutil="${_gnatbin##*/}"
+		ln -s "$_gnatbin" "${_gnatutil%"-$gccver"}" || \
+		    $err "E: ln -s \"$_gnatbin\" \"${_gnatutil%"-$gccver"}\""
+	done
+	) || $err "Cannot create gnat-$gccver link in $gccdir"
+}