1)I could not find semaphore.h(asm/semaphore.h) in fedora 10....is there any replacement for it..
2) when i tried to use udev functionality and when i used class_create_device() function it says...error:implicit declaration..why did this occur..
3)klogd doesn't work in fd10 ..rsyslogd and others are also not working..is there any replacement for it...

How about actually telling us what you're trying to do? semaphore.h is still present in the latest Linux offerings, as is udev, and remote syslogging.

sir..I did not do anything with semaphores..I was trying to port an old code(module code) on to fd 10 which inluded the header file<asm/semaphore.h>(which gave an error)...
and regarding udev I was trying to create kobject using class_device_create() but it did not work...I solved this by device_create() on fd10...which worked(dont know whether it was correct but the signatures matched <linux/device.h>)
..and it was not about remote syslogging "klogd" is about kernel log buffer (to print on root console or /var/log/messages) settings

porting old code ?
well use ether " gcc3.4 " or rewright the code so it is compatable with " gcc 4.3 "
for gcc3.4 you will need to group install the " legacy tools"
also if it built using gcc4.1( fedora 7,8 )but not gcc4.3 then additional " #include " ????" will needed to be added in the .cpp code
see
http://gcc.gnu.org/gcc-4.3/porting_to.html