Work around gcc stupidity: With -MM gcc outputs just the basename of files as

target name. This breaks when compiling targets in subdirectories, so prepend
the subdirectory name to the target name.

Originally committed as revision 12398 to svn://svn.ffmpeg.org/ffmpeg/trunk

common.mak

@@ -61,8 +61,9 @@ $(SLIBNAME_WITH_MAJOR): $(OBJS)
 ALLHEADERS = $(subst $(LIBSRC)/,,$(wildcard $(LIBSRC)/*.h))
 checkheaders: $(filter-out %_template.ho,$(ALLHEADERS:.h=.ho))
 
+# gcc stupidly only outputs the basename of targets with -MM
 depend dep: $(SRCS)
-	$(CC) -MM $(CFLAGS) $^ 1>.depend
+	$(CC) -MM $(CFLAGS) $^ | sed 's,[0-9a-z._-]*: \([a-z0-9]*/\).*,\1&,' 1>.depend
 
 clean::
 	rm -f *.o *~ *.a *.lib *.so *.so.* *.dylib *.dll \