From 06d2d0c6ef9ec8d14f3423d0ddf5e17e444cdc02 Mon Sep 17 00:00:00 2001
From: Marcel Bargull <marcel.bargull@udo.edu>
Date: Fri, 6 Nov 2020 09:03:32 +0100
Subject: [PATCH] Use CPP, CC and flags in dep check scripts

Allow build systems without standard cc to successfully run the
dependency checking helper scripts from the Makefile.
This supports custom compilers specified by the common CC environment
variable, preprocessors given as CPP and additional preprocessor flags
from CPPFLAGS.
Additional flags from CFLAGS and LDFLAGS are considered for compiling/linking.
Overall, this facilitates cross-compilation and similar setups.

Signed-off-by: Marcel Bargull <marcel.bargull@udo.edu>
---
 hack/btrfs_installed_tag.sh | 2 +-
 hack/btrfs_tag.sh           | 2 +-
 hack/libdm_tag.sh           | 2 +-
 hack/systemd_tag.sh         | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/hack/btrfs_installed_tag.sh b/hack/btrfs_installed_tag.sh
index c4d99f377f..f2f2b33c83 100755
--- a/hack/btrfs_installed_tag.sh
+++ b/hack/btrfs_installed_tag.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-cc -E - > /dev/null 2> /dev/null << EOF
+${CPP:-${CC:-cc} -E} ${CPPFLAGS} - > /dev/null 2> /dev/null << EOF
 #include <btrfs/ioctl.h>
 EOF
 if test $? -ne 0 ; then
diff --git a/hack/btrfs_tag.sh b/hack/btrfs_tag.sh
index 59cb969ad6..ea753d4d02 100755
--- a/hack/btrfs_tag.sh
+++ b/hack/btrfs_tag.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-cc -E - > /dev/null 2> /dev/null << EOF
+${CPP:-${CC:-cc} -E} ${CPPFLAGS} - > /dev/null 2> /dev/null << EOF
 #include <btrfs/version.h>
 EOF
 if test $? -ne 0 ; then
diff --git a/hack/libdm_tag.sh b/hack/libdm_tag.sh
index d3668aab1c..815b5d914e 100755
--- a/hack/libdm_tag.sh
+++ b/hack/libdm_tag.sh
@@ -2,7 +2,7 @@
 tmpdir="$PWD/tmp.$RANDOM"
 mkdir -p "$tmpdir"
 trap 'rm -fr "$tmpdir"' EXIT
-cc -o "$tmpdir"/libdm_tag -ldevmapper -x c - > /dev/null 2> /dev/null << EOF
+${CC:-cc} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS} -o "$tmpdir"/libdm_tag -x c - -ldevmapper > /dev/null 2> /dev/null << EOF
 #include <libdevmapper.h>
 int main() {
 	struct dm_task *task;
diff --git a/hack/systemd_tag.sh b/hack/systemd_tag.sh
index 19a7bf6a64..5af3228816 100755
--- a/hack/systemd_tag.sh
+++ b/hack/systemd_tag.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-cc -E - > /dev/null 2> /dev/null << EOF
+${CPP:-${CC:-cc} -E} ${CPPFLAGS} - > /dev/null 2> /dev/null << EOF
 #include <systemd/sd-daemon.h>
 EOF
 if test $? -eq 0 ; then