build: Fix support for split build and source dirs

Building LXC in a separate target directory, by running configure from
outside the source tree, failed with multiple errors, mostly in the
Python and Lua extensions, due to assuming the source dir and build dir
are the same in a few places. To fix that:

- Pre-process setup.py with the appropriate directories at configure
  time
- Introduce the build dir as an include path in the Lua Makefile
- Link the default container configuration file from the alternatives
  in the configure stage, instead of setting a variable and using it
  in the Makefile

Signed-off-by: Daniel Miranda <danielkza2@gmail.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>

config/etc/Makefile.am

@@ -1,12 +1,8 @@
 configdir = $(sysconfdir)/lxc
 config_DATA = default.conf
-distroconf = @LXC_DISTRO_CONF@
 
 EXTRA_DIST = default.conf.ubuntu default.conf.libvirt default.conf.unknown
 
-default.conf:
-	cp $(distroconf) $@
-
 clean-local:
 	@$(RM) -f default.conf
 

configure.ac

@@ -73,6 +73,8 @@ AC_MSG_RESULT([$with_distro])
 AM_CONDITIONAL([HAVE_DEBIAN], [test x"$with_distro" = "xdebian" -o x"$with_distro" = "xubuntu" -o x"$with_distro" = "xraspbian"])
 AM_CONDITIONAL([DISTRO_UBUNTU], [test "x$with_distro" = "xubuntu"])
 
+AC_CONFIG_LINKS([config/etc/default.conf:config/etc/${distroconf}])
+
 # Check for init system type
 AC_MSG_CHECKING([for init system type])
 AC_ARG_WITH([init-script],
@@ -488,7 +490,6 @@ AS_AC_EXPAND(LXC_DEFAULT_CONFIG, "$sysconfdir/lxc/default.conf")
 AS_AC_EXPAND(DATADIR, "$datadir")
 AS_AC_EXPAND(LOCALSTATEDIR, "$localstatedir")
 AS_AC_EXPAND(DOCDIR, "$docdir")
-AS_AC_EXPAND(LXC_DISTRO_CONF, "$distroconf")
 AS_AC_EXPAND(LXC_GENERATE_DATE, "$(date)")
 AS_AC_EXPAND(LXCPATH, "$with_config_path")
 AS_AC_EXPAND(LXC_GLOBAL_CONF, "$with_global_conf")
@@ -717,6 +718,7 @@ AC_CONFIG_FILES([
 	src/lxc/lxc.functions
 	src/lxc/version.h
 	src/python-lxc/Makefile
+	src/python-lxc/setup.py
 
 	src/lua-lxc/Makefile
 

src/lua-lxc/Makefile.am

@@ -11,13 +11,13 @@ so_PROGRAMS = core.so
 
 core_so_SOURCES = core.c
 
-AM_CFLAGS=-I$(top_srcdir)/src $(LUA_CFLAGS) -DVERSION=\"$(VERSION)\" -DLXCPATH=\"$(LXCPATH)\"
+AM_CFLAGS=-I$(top_builddir)/src -I$(top_srcdir)/src $(LUA_CFLAGS) -DVERSION=\"$(VERSION)\" -DLXCPATH=\"$(LXCPATH)\"
 
 core_so_CFLAGS = -fPIC -DPIC $(AM_CFLAGS)
 
 core_so_LDFLAGS = \
 	-shared \
-	-L$(top_srcdir)/src/lxc \
+	-L$(top_builddir)/src/lxc \
 	-Wl,-soname,core.so.$(firstword $(subst ., ,$(VERSION)))
 
 core_so_LDADD = -llxc

src/python-lxc/Makefile.am

@@ -7,7 +7,7 @@ else
 endif
 
 all:
-	CFLAGS="$(CFLAGS) -I ../../src -L../../src/lxc/" $(PYTHON) setup.py build
+	$(PYTHON) setup.py build
 
 install:
 	if [ "$(DESTDIR)" = "" ]; then \
@@ -21,7 +21,6 @@ clean-local:
 
 endif
 EXTRA_DIST = \
-	setup.py \
 	lxc.c \
 	lxc/__init__.py \
 	examples/api_test.py \

src/python-lxc/setup.py → src/python-lxc/setup.py.in

@@ -19,15 +19,18 @@
 #
 # You should have received a copy of the GNU Lesser General Public
 # License along with this library; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
+# USA
 
 from distutils.core import setup, Extension
 
-module = Extension('_lxc', sources=['lxc.c'], libraries=['lxc'])
+module = Extension('_lxc', sources=['@srcdir@/lxc.c'],
+                   include_dirs=['@top_builddir@/src', '@top_srcdir@/src'],
+                   library_dirs=['@top_builddir@/src/lxc'], libraries=['lxc'])
 
 setup(name='_lxc',
       version='0.1',
       description='LXC',
       packages=['lxc'],
-      package_dir={'lxc': 'lxc'},
+      package_dir={'lxc': '@srcdir@/lxc'},
       ext_modules=[module])