From 14b094484e5660b9014780e73bd01517f3dd4afd Mon Sep 17 00:00:00 2001
From: Stefan Strogin <steils@gentoo.org>
Date: Wed, 31 Jul 2019 10:58:06 +0300
Subject: [PATCH] kpatch-build: check if gcc supports -gz=none

The flag -gz[=type] was added in GCC 5. To support older GCC versions
check if the flag is supported before adding it to KCFLAGS.

Fixes: #1012

Signed-off-by: Stefan Strogin <steils@gentoo.org>
---
 kpatch-build/kpatch-build | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/kpatch-build/kpatch-build b/kpatch-build/kpatch-build
index 365655c..69c1301 100755
--- a/kpatch-build/kpatch-build
+++ b/kpatch-build/kpatch-build
@@ -50,6 +50,7 @@ DEBUG=0
 SKIPCLEANUP=0
 SKIPGCCCHECK=0
 ARCH_KCFLAGS=""
+DEBUG_KCFLAGS=""
 declare -a PATCH_LIST
 APPLIED_PATCHES=0
 OOT_MODULE=
@@ -205,7 +206,6 @@ gcc_version_check() {
 	else
 		kgccver="$(gcc_version_from_file "$VMLINUX")"
 	fi
-	rm -f "$c" "$o"
 
 	if [[ -n "$out" ]]; then
 		warn "gcc >= 4.8 required for -pg -ffunction-settings"
@@ -213,6 +213,12 @@ gcc_version_check() {
 		return 1
 	fi
 
+	out="$(gcc -c -gz=none -o "$o" "$c" 2>&1)"
+	if [[ -z "$out" ]]; then
+		DEBUG_KCFLAGS="-gz=none"
+	fi
+	rm -f "$c" "$o"
+
 	# ensure gcc version matches that used to build the kernel
 	if [[ "$gccver" != "$kgccver" ]]; then
 		warn "gcc/kernel version mismatch"
@@ -748,7 +754,8 @@ if [[ "$ARCH" = "ppc64le" ]]; then
 	ARCH_KCFLAGS="-mcmodel=large -fplugin=$PLUGINDIR/ppc64le-plugin.so"
 fi
 
-export KCFLAGS="-I$DATADIR/patch -ffunction-sections -fdata-sections -gz=none $ARCH_KCFLAGS"
+export KCFLAGS="-I$DATADIR/patch -ffunction-sections -fdata-sections \
+		$ARCH_KCFLAGS $DEBUG_KCFLAGS"
 
 echo "Reading special section data"
 find_special_section_data