build: cache modules from playground

Now that we are able to build our own test modules, also allow to use
cached modules so a) kernel headers are not required and b) distro
maintainers are happy.  It's still need a "--disable-test-modules" in
the configure since the default is enabled.

There's no license problems anymore since all modules come from our own
repository, we ship the sources and the modules can be easily rebuilt.

Makefile.am

@@ -230,7 +230,12 @@ build-module-playground:
 		cp -r $(top_srcdir)/$(MODULE_PLAYGROUND) $(top_builddir)/$(MODULE_PLAYGROUND) && \
 		find $(top_builddir)/$(MODULE_PLAYGROUND) -type d -exec chmod +w {} \; ; \
 		fi
+if BUILD_MODULES
 	$(MAKE) -C $(MODULE_PLAYGROUND)
+else
+	$(MAKE) -C $(MODULE_PLAYGROUND) FAKE_BUILD=1
+endif
+
 
 rootfs: build-module-playground
 	$(CREATE_ROOTFS)

configure.ac

@@ -127,6 +127,11 @@ AC_ARG_ENABLE([manpages],
 	[], enable_manpages=yes)
 AM_CONDITIONAL([BUILD_MANPAGES], [test "x$enable_manpages" = "xyes"])
 
+AC_ARG_ENABLE([test-modules],
+        AS_HELP_STRING([--disable-test-modules], [disable building test modules during make check: cached modules will be used @<:@default=enabled@:>@]),
+	[], enable_test_modules=yes)
+AM_CONDITIONAL([BUILD_MODULES], [test "x$enable_test_modules" = "xyes"])
+
 AC_ARG_ENABLE([logging],
 	AS_HELP_STRING([--disable-logging], [disable system logging @<:@default=enabled@:>@]),
 	[], enable_logging=yes)
@@ -282,4 +287,5 @@ AC_MSG_RESULT([
 	coverage:		${enable_coverage}
 	doc:			${enable_gtk_doc}
 	man:			${enable_manpages}
+	test-modules:           ${enable_test_modules}
 ])

testsuite/module-playground/.gitignore

@@ -1,6 +1,7 @@
 *o.cmd
 *.ko
 !mod-simple-*.ko
+!cache/*.ko
 *.mod.c
 .tmp_versions
 modules.order

testsuite/module-playground/Makefile

@@ -38,6 +38,9 @@ else
 # normal makefile
 KDIR ?= /lib/modules/`uname -r`/build
 KVER ?= `uname -r`
+ifeq ($(FAKE_BUILD),)
+    FAKE_BUILD=0
+endif
 
 ARCH_SPECIFIC_MODULES := mod-simple-x86_64.ko mod-simple-i386.ko mod-simple-sparc64.ko
 MY_MODULES := $(filter-out $(ARCH_SPECIFIC_MODULES),$(wildcard *.ko))
@@ -48,8 +51,14 @@ mod-simple-%.ko: mod-simple-%.c Makefile.arch
 	$(eval arch=$(patsubst mod-simple-%.ko,%,$@))
 	$(MAKE) KDIR=$(KDIR_$(arch)) ARCH=$(arch) CROSS_COMPILE=$(CROSS_COMPILE_$(arch)) -f Makefile.arch
 
+ifeq ($(FAKE_BUILD),0)
 modules:
 	$(MAKE) -C $(KDIR) M=$$PWD
+else
+modules:
+	@echo "  CP       cache/*.ko"
+	@cp cache/*.ko .
+endif
 
 arch-modules: $(ARCH_SPECIFIC_MODULES)