support clang build

(cherry picked from commit d784ff7fe72bb273828b5f852218d02f07a76a0d)

grubby.spec

@@ -1,6 +1,6 @@
 Name: grubby
 Version: 8.40
-Release: 31
+Release: 32
 Summary: Update and display information about the configuration files
 License: GPLv2+
 URL: https://github.com/rhinstaller/grubby
@@ -36,6 +36,7 @@ Patch6017: backport-Fix-maybe-uninitialized-warning.patch
 Patch9001: fix-make-test-fail-when-no-boot-partition.patch
 Patch9002: 0001-add-loongarch-support-for-grubby.patch
 Patch9003: grubby-aarch64-skip-test-grub2.15.patch
+Patch9004: support-specify-cc.patch
 
 BuildRequires: gcc pkgconfig glib2-devel popt-devel
 BuildRequires: libblkid-devel git-core sed make
@@ -110,6 +111,9 @@ sed -e "s,@@LIBEXECDIR@@,%{_libexecdir}/installkernel,g" %{SOURCE3} > %{buildroo
 %{_mandir}/man8/*.8*
 
 %changelog
+* Fri Apr 14 2023 jammyjellyfish <jammyjellyfish255@outlook.com> - 8.40-32
+- Support build with clang
+
 * Sat Feb 18 2023 zhangnan <zhangnan134@huawei.com> - 8.40-31
 - enable make test
 

support-specify-cc.patch

@@ -0,0 +1,12 @@
+diff -up grubby-8.40-1/Makefile.orig2 grubby-8.40-1/Makefile
+--- grubby-8.40-1/Makefile.orig2	2023-04-14 22:13:21.745311816 +0800
++++ grubby-8.40-1/Makefile	2023-04-14 22:14:02.729398198 +0800
+@@ -22,7 +22,7 @@ VERSION=8.40
+ TARGETS = grubby
+ OBJECTS = grubby.o log.o
+ 
+-CC = gcc
++CC ?= gcc
+ RPM_OPT_FLAGS ?= -O2 -g -pipe -Wp,-D_FORTIFY_SOURCE=2 -fstack-protector
+ CFLAGS += $(RPM_OPT_FLAGS) -std=gnu99 -Wall -Werror -Wno-error=unused-function -Wno-unused-function -ggdb
+ LDFLAGS := $(RPM_LD_FLAGS)