Date: Thu, 19 Nov 2009 10:27:41 +0100 From: "Matthias Andree" <matthias.andree@gmx.de> To: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org> Subject: header file bug sys/types.h sys/file.h vs. _XOPEN_SOURCE standard Message-ID: <op.u3mxwfh21e62zd@balu.cs.uni-paderborn.de>
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Greetings,
this little C program (which is actual a minimum excerpt from
sysutils/e2fsprogs) fails to compile on - among others - 8.0-PRERELEASE:
$ cat fail.c
#define _XOPEN_SOURCE 600
#include <sys/file.h>
$ gcc -W -Wall -O -c fail.c
In file included from fail.c:2:
/usr/include/sys/file.h:161: error: expected specifier-qualifier-list
before 'u_int'
I can get the code to compile by removing the "#define _XOPEN_SOURCE 600".
This happens here:
146 /*
147 * Userland version of struct file, for sysctl
148 */
149 struct xfile {
150 size_t xf_size; /* size of struct xfile */
151 pid_t xf_pid; /* owning process */
152 uid_t xf_uid; /* effective uid of owning process
*/
153 int xf_fd; /* descriptor number */
154 void *xf_file; /* address of struct file */
155 short xf_type; /* descriptor type */
156 int xf_count; /* reference count */
157 int xf_msgcount; /* references from message queue */
158 off_t xf_offset; /* file offset */
159 void *xf_data; /* file descriptor specific data */
160 void *xf_vnode; /* vnode pointer */
!! 161 u_int xf_flag; /* flags (see fcntl.h) */
162 };
The flow here is as follows:
1. sys/file.h (non-standard header) includes sys/types.h (POSIX/XSI
standard header) and implictly sys/cdefs.h
2. since _XOPEN_SOURCE is defined, nonstandard symbols such as u_int
aren't defined by the standard headers (this is in line with IEEE Std
1003.1-2008)
3. sys/file.h uses this non-standard and undefined u_int and breaks.
I've talked to Theodore Y. Ts'o, who is the sysutils/e2fsprogs upstream
maintainer and proposed to remove the _XOPEN_SOURCE definition (my idea
was that the code shouldn't be claiming standards compliance while it uses
non-standard headers), but he refused that (since it would break the
e2fsprogs build on Solaris).
Should non-standard system headers break if an application defines one of
the standard feature test macros? Or could sys/file.h be changed (for
instance by replacing u_int by unsigned int) to tolerate POSIX and XSI
feature test macros?
TIA.
Cheers
--
Matthias Andree
mandree freebsd org
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