support clang build

(cherry picked from commit ea42ad79b2cba7ec73ef200a6043d0bac477f4e4)

efivar.spec

@@ -1,6 +1,6 @@
 Name:           efivar
 Version:        38
-Release:        4
+Release:        5
 Summary:        Tools and libraries to work with EFI variables
 License:        LGPL-2.1-only
 URL:            https://github.com/rhboot/%{name}
@@ -41,7 +41,10 @@ Development titles to use libefivar must be included.
 
 %build
 export LDFLAGS="-flto-partition=none"
-%make_build
+%if "%{?toolchain}" == "clang"
+  %global make_opts CC=clang CXX=clang++
+%endif
+%make_build %{?make_opts}
 
 %install
 %make_install
@@ -74,6 +77,12 @@ install -m 0644 src/abignore %{buildroot}%{_includedir}/efivar/.abignore
 %{_mandir}/man3/*
 
 %changelog
+* Mon Apr 1 2024 luofeng13 <luofeng13@huawei.com> - 38-5
+- Type:enhancement
+- ID:NA
+- SUG:NA
+- DESC:support clang build
+
 * Wed Mar 13 2024 zhouyihang <zhouyihang3@h-partners.com> - 38-4
 - Type:bugfix
 - ID:NA