kern/165559: ufsmount.h uses the 'export' keyword as a structure member name

Jim C. jim at
Wed Feb 29 17:50:11 UTC 2012

>Number:         165559
>Category:       kern
>Synopsis:       ufsmount.h uses the 'export' keyword as a structure member name
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Wed Feb 29 17:50:11 UTC 2012
>Originator:     Jim C.
>Release:        8.2-RELEASE-p4
Carroll-Net, Inc.
FreeBSD 8.2-RELEASE-p4 FreeBSD 8.2-RELEASE-p4 #0: Fri Nov 18 15:50:11 EST 2011

While compiling some GNU C++ code against the include file /usr/include/ufs/ufs/ufsmount.h, we discovered the ufs_args structure has a member variable named 'export'. G++ chokes with the following error:

/usr/include/ufs/ufs/ufsmount.h:43: error: expected unqualified-id before 'export'

The reason is that the term 'export' is a reserved, but presently unused keyword in the C++ language.

To solve our problem, we've copied the header locally to our project folder, and renamed the reference. But if possible, I was hoping this could be folded back into the main tree.

I recognize this could present a breaking change for any projects that link against libufs -- but sooner or later this change will need to be accepted or someone is going to have to convince the folks at GNU/C++ to add a compiler directive to ignore the 'export' keyword (fyi -- I checked, but so far this looks like a no go).

FYI -- the folks at the openssl project encountered had a similar problem and eventually they were forced to just rename the member variable.
Create my.cpp, paste in

    #include <sys/param.h>
    #include <sys/mount.h>
    #include <ufs/ufs/ufsmount.h>
    #include <ufs/ufs/dinode.h>
    #include <ufs/ffs/fs.h>
    #include <libufs.h>

g++ -c my.cpp

--- ufsmount.h	2012-02-29 12:33:04.000000000 -0500
+++ /usr/include/ufs/ufs/ufsmount.h	2012-02-29 12:32:28.000000000 -0500
@@ -40,7 +40,7 @@
 struct ufs_args {
 	char	*fspec;			/* block special device to mount */
-	struct	oexport_args export_;	/* network export information */
+	struct	oexport_args export;	/* network export information */
 #ifdef _KERNEL


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