fix ability to pass compile-time build options when building from the hg repo

From: Michael Krufky <mkrufky@linuxtv.org>

When building in-kernel, compile-time build options are passed into the
compiler using '#include <linux/config.h>' .  This file #include's
<linux/autoconf.h> , which is created on the fly by the kbuild system.

However, this does not work correctly when building from the mercurial
repository, since the kernel is built indepentently of v4l/.myconfig

This creates a "config-compat.h", which will be #include'd by compat.h
and will emulate <linux/config.h> for the local build.

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>

3 files changed, 21 insertions, 2 deletions

diff --git a/v4l/Makefile b/v4l/Makefile
index 58b160397..3ba4603f3 100644
--- a/v4l/Makefile
+++ b/v4l/Makefile
@@ -25,7 +25,7 @@ endif
 #################################################
 # default compilation rule
 
-default:: Makefile.media links .version
+default:: config-compat.h Makefile.media links .version
 	echo srcdir $(SRCDIR)
 	$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) $(MYCFLAGS) modules
 
@@ -188,6 +188,22 @@ links::
 	@find ../linux/drivers/media -name '*.[ch]' -type f -exec ln -sf '{}' . \;
 	@find ../linux/sound -name '*.[ch]' -type f -exec ln -sf '{}' . \;
 
+config-compat.h:: .myconfig
+	@echo \#ifndef __CONFIG_COMPAT_H__ > config-compat.h
+	@echo \#define __CONFIG_COMPAT_H__ >> config-compat.h
+	@echo >> config-compat.h
+	@echo \#include \<linux\/config\.h\> >> config-compat.h
+	@echo >> config-compat.h
+	@grep "CONFIG\_" .myconfig | grep -v "\:\= n" | \
+		sed s/"CONFIG\_"/"\#undef CONFIG\_"/1 | \
+		sed s/"\:\= ."/""/1 >> config-compat.h >> config-compat.h
+	@echo >> config-compat.h
+	@grep "CONFIG\_" .myconfig | grep -v "\:\= n" | \
+		sed s/"CONFIG\_"/"\#define CONFIG\_"/1 | \
+		sed s/"\:\="/""/1 >> config-compat.h >> config-compat.h
+	@echo >> config-compat.h
+	@echo \#endif >> config-compat.h
+
 kernel-links makelinks::
 	cd ..;	v4l/scripts/makelinks.sh $(KDIR)
 
@@ -204,7 +220,7 @@ clean::
 	@find . -name '*.c' -type l -exec rm '{}' \;
 	@find . -name '*.h' -type l -exec rm '{}' \;
 	-rm -f *~ *.o *.ko .*.o.cmd .*.ko.cmd *.mod.c av7110_firm.h fdump \
-		ivtv-svnversion.h 
+		ivtv-svnversion.h config-compat.h
 
 distclean:: clean
 	-rm -f .version .*.o.flags .*.o.d Makefile.media \
diff --git a/v4l/compat.h b/v4l/compat.h
index 0bcb238fb..b9138c7be 100644
--- a/v4l/compat.h
+++ b/v4l/compat.h
@@ -10,6 +10,7 @@
 #include <linux/version.h>
 #include <linux/utsname.h>
 #include <linux/sched.h>
+#include "config-compat.h"
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,18)
 # define minor(x) MINOR(x)
diff --git a/v4l/scripts/makelinks.sh b/v4l/scripts/makelinks.sh
index a66989771..03fd48849 100755
--- a/v4l/scripts/makelinks.sh
+++ b/v4l/scripts/makelinks.sh
@@ -39,10 +39,12 @@ done
 
 for x in `find include -type d | grep -v CVS` ; do
 	ln -f -s $PWD/../v4l/compat.h $1/$x/compat.h
+	touch $1/$x/config-compat.h
 done
 
 for x in `find drivers/media -type d | grep -v CVS` ; do
 	ln -f -s $PWD/../v4l/compat.h $1/$x/compat.h
+	touch $1/$x/config-compat.h
 done
 
 cd ..