Allow RPMS to be built on ppc64 and aarch64 by making luajit optional

Not all architectures have luajit supported.  The bcc configure and
build were already was set up to make the luajit dependent parts
optional.  The bcc.spec now makes the luajit dependent parts optional
too allowing Fedora 25 builds on ppc64, ppc64le, and aarch64.  This
change has been tested and allows the resulting srpm to build on the
Fedora koji build system for the newly added architectures.
Signed-off-by: William Cohen <wcohen@redhat.com>

SPECS/bcc.spec

 %bcond_with local_clang_static
+#lua jit not available for some architectures
+%ifarch ppc64 aarch64 ppc64le
+%{!?with_lua: %global with_lua 0}
+%else
+%{!?with_lua: %global with_lua 1}
+%endif
 %define debug_package %{nil}
 
 Name:           bcc
@@ -11,10 +17,12 @@ License:        ASL 2.0
 URL:            https://github.com/iovisor/bcc
 Source0:        bcc.tar.gz
 
-ExclusiveArch: x86_64
+ExclusiveArch: x86_64 ppc64 aarch64 ppc64le
 BuildRequires: bison cmake >= 2.8.7 flex make
 BuildRequires: gcc gcc-c++ python2-devel elfutils-libelf-devel-static
+%if %{with_lua}
 BuildRequires: luajit luajit-devel
+%endif
 %if %{without local_clang_static}
 BuildRequires: llvm-devel llvm-static
 BuildRequires: clang-devel
@@ -25,6 +33,11 @@ BuildRequires: pkgconfig ncurses-devel
 Python bindings for BPF Compiler Collection (BCC). Control a BPF program from
 userspace.
 
+%if %{with_lua}
+%global lua_include `pkg-config --variable=includedir luajit`
+%global lua_libs `pkg-config --variable=libdir luajit`/lib`pkg-config --variable=libname luajit`.so
+%global lua_config -DLUAJIT_INCLUDE_DIR=%{lua_include} -DLUAJIT_LIBRARIES=%{lua_libs}
+%endif
 
 %prep
 %setup -q -n bcc
@@ -35,8 +48,7 @@ mkdir build
 pushd build
 cmake .. -DREVISION_LAST=%{version} -DREVISION=%{version} \
       -DCMAKE_INSTALL_PREFIX=/usr \
-      -DLUAJIT_INCLUDE_DIR=`pkg-config --variable=includedir luajit` \
-      -DLUAJIT_LIBRARIES=`pkg-config --variable=libdir luajit`/lib`pkg-config --variable=libname luajit`.so
+      %{?lua_config}
 make %{?_smp_mflags}
 popd
 
@@ -56,16 +68,20 @@ Requires: libbcc = %{version}-%{release}
 %description -n python-bcc
 Python bindings for BPF Compiler Collection (BCC)
 
+%if %{with_lua}
 %package -n bcc-lua
 Summary: Standalone tool to run BCC tracers written in Lua
 Requires: libbcc = %{version}-%{release}
 %description -n bcc-lua
 Standalone tool to run BCC tracers written in Lua
+%endif
 
 %package -n libbcc-examples
 Summary: Examples for BPF Compiler Collection (BCC)
 Requires: python-bcc = %{version}-%{release}
+%if %{with_lua}
 Requires: bcc-lua = %{version}-%{release}
+%endif
 %description -n libbcc-examples
 Examples for BPF Compiler Collection (BCC)
 
@@ -82,8 +98,10 @@ Command line tools for BPF Compiler Collection (BCC)
 %files -n python-bcc
 %{python_sitelib}/bcc*
 
+%if %{with_lua}
 %files -n bcc-lua
 /usr/bin/bcc-lua
+%endif
 
 %files -n libbcc-examples
 /usr/share/bcc/examples/*