'present but cannot be compiled' error for linux/cdrom.h

[Richard Smith]

Hey. I get the following error quite a lot, for various linux headers:

checking linux/cdrom.h usability... no
checking linux/cdrom.h presence... yes
configure: WARNING: linux/cdrom.h: present but cannot be compiled
configure: WARNING: linux/cdrom.h: check for missing prerequisite headers?
configure: WARNING: linux/cdrom.h: proceeding with the preprocessor's result
configure: WARNING:     ## ------------------------------------ ##
configure: WARNING:     ## Report this to address@hidden ##
configure: WARNING:     ## ------------------------------------ ##
checking for linux/cdrom.h... yes

The error arises when ./configure'ing various KDE packages (the above is from 
the kdemultimedia package). As far as I can see, the cause of the error is 
the presence of the -ansi flag on the gcc command line.

The configure.in.in line for the check is:

AC_CHECK_HEADERS(linux/cdrom.h)

Relevant extract of config.log: (can send complete log if this is not enough)

configure:29618: checking linux/cdrom.h usability
configure:29631: gcc -c -ansi -W -Wall -Wchar-subscripts -Wshadow 
-Wpointer-arith -Wmissing-prototypes -Wwrite-strings -D_XOPEN_SOURCE=500
In file included from /usr/include/linux/cdrom.h:14,
                 from conftest.c:88:
/usr/include/asm/byteorder.h:38: syntax error before "__u64"
[...]
configure:29634: $? = 1
configure: failed program was:
[...]
| #include <linux/cdrom.h>
configure:29650: result: no
configure:29654: checking linux/cdrom.h presence
configure:29665: gcc -E  -DQT_THREAD_SUPPORT  -D_REENTRANT conftest.c
configure:29671: $? = 0
configure:29690: result: yes
configure:29710: WARNING: linux/cdrom.h: present but cannot be compiled
configure:29712: WARNING: linux/cdrom.h: check for missing prerequisite 
headers?
configure:29714: WARNING: linux/cdrom.h: proceeding with the preprocessor's 
result
configure:29726: checking for linux/cdrom.h
configure:29733: result: yes


Hope this is helpful. I can send more information if it's needed.

Richard Smith