Conditional usage of clang. Enable it to test building on ABF.

samba.spec

@@ -31,6 +31,7 @@
 %define sambaerrorsmajor 1
 
 # Default options
+%bcond_without clang
 %bcond_with doc
 %bcond_with cifs
 %bcond_without ads
@@ -100,7 +101,7 @@
 Summary:	Samba SMB server
 Name:		samba
 Version:	4.9.4
-Release:	5
+Release:	6
 Epoch:		1
 License:	GPLv3+
 Group:		System/Servers
@@ -135,10 +136,13 @@ Patch9:		DEBIAN-s3-auth-ignore-create_builtin_guests-failing-without.patch
 Patch10:	ROSA-vendor-version.patch
 Patch11:	ROSA-smb-default-config.patch
 
+%if %{with clang}
+BuildRequires:	clang lld
+%else
+BuildRequires:	gcc
+%endif
 # Required for ldb docs
 BuildRequires:	docbook-style-xsl
-# For -fuse-ld
-BuildRequires:	gcc
 BuildRequires:	gnupg
 BuildRequires:	perl-Parse-Yapp
 BuildRequires:	python-tdb
@@ -1476,6 +1480,12 @@ sed -e 's/@ROSA_VENDOR_PATCH@/%{release}/g' -i VERSION
 %build
 install -d -m 0755 %{buildroot}/%{_libdir}/samba
 
+%if %{with clang}
+export CC=clang
+export CXX=clang++
+export CPP=clang-cpp
+%endif
+
 export CFLAGS="-O2 -g"
 
 chmod +x ./buildtools/bin/waf