[PATCH v3] kbuild: add debug package to pacman PKGBUILD

[Jose Fernandez <jose.fernandez@linux.dev>]

Add a new debug package to the PKGBUILD for the pacman-pkg target. The
debug package includes the non-stripped vmlinux file with debug symbols
for kernel debugging and profiling. The file is installed at
/usr/src/debug/${pkgbase}, with a symbolic link at
/usr/lib/modules/$(uname -r)/build/vmlinux. The debug package is built
by default.

Signed-off-by: Jose Fernandez <jose.fernandez@linux.dev>
Reviewed-by: Peter Jung <ptr1337@cachyos.org>
---
v2->v3:
- Remove unnecessary mkdir -p "$pkgdir/usr/src/debug/${pkgbase}"
- Use the new _prologue() function [1]
- Add symbolic link to /usr/lib/modules/$(uname -r)/build/vmlinux
- Remove the dependency on the headers package
v1->v2:
- Use the new PACMAN_EXTRAPACKAGES [2] variable to allow users to disable the
debug package if desired, instead of always including it.

[1] https://lore.kernel.org/lkml/20240816141844.1217356-1-masahiroy@kernel.org/
[2] https://lore.kernel.org/lkml/20240813185900.GA140556@thelio-3990X/T/

 scripts/package/PKGBUILD | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/scripts/package/PKGBUILD b/scripts/package/PKGBUILD
index 839cd5e634d2..f83493838cf9 100644
--- a/scripts/package/PKGBUILD
+++ b/scripts/package/PKGBUILD
@@ -5,7 +5,7 @@
 pkgbase=${PACMAN_PKGBASE:-linux-upstream}
 pkgname=("${pkgbase}")
 
-_extrapackages=${PACMAN_EXTRAPACKAGES-headers api-headers}
+_extrapackages=${PACMAN_EXTRAPACKAGES-headers api-headers debug}
 for pkg in $_extrapackages; do
 	pkgname+=("${pkgbase}-${pkg}")
 done
@@ -111,6 +111,19 @@ _package-api-headers() {
 	${MAKE} headers_install INSTALL_HDR_PATH="${pkgdir}/usr"
 }
 
+_package-debug(){
+	pkgdesc="Non-stripped vmlinux file for the ${pkgdesc} kernel"
+
+	local debugdir="${pkgdir}/usr/src/debug/${pkgbase}"
+	local builddir="${pkgdir}/usr/${MODLIB}/build"
+
+	_prologue
+
+	install -Dt "${debugdir}" -m644 vmlinux
+	mkdir -p "${builddir}"
+	ln -sr "${debugdir}/vmlinux" "${builddir}/vmlinux"
+}
+
 for _p in "${pkgname[@]}"; do
 	eval "package_$_p() {
 		$(declare -f "_package${_p#$pkgbase}")

base-commit: df829331cf5cccb2a1fdd7560eabfcec49f9b990
-- 
2.46.0