From: YASUOKA Masahiko <yasuoka@openbsd.org>
Subject: Re: x11/gentoo build fix for opaque FILE
To: tb@theobuehler.org
Cc: ports@openbsd.org
Date: Tue, 15 Jul 2025 15:44:57 +0900

On Sun, 13 Jul 2025 00:09:07 +0200
Theo Buehler <tb@theobuehler.org> wrote:
> I don't think this code is actually used. The static FILE themselves
> are just placeholders as is explained in the nearby comments. Instead
> of addresses to statics, we can just open the files normally use the
> pointers for copmarison and close them again.

My diff below fixes the same problem by putting a dummy __sFILE.  The
downside of this is the patch can only be applied after the stdio
opaque patch.

(I've sent the diff for x11/gentoo for hackers@ with the diffs for
 others)

Index: x11/gentoo/patches/patch-src_mntent_wrap_c
===================================================================
RCS file: x11/gentoo/patches/patch-src_mntent_wrap_c
diff -N x11/gentoo/patches/patch-src_mntent_wrap_c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ x11/gentoo/patches/patch-src_mntent_wrap_c	15 Jul 2025 01:27:46 -0000
@@ -0,0 +1,15 @@
+Index: src/mntent_wrap.c
+--- src/mntent_wrap.c.orig
++++ src/mntent_wrap.c
+@@ -101,6 +101,11 @@ gint mne_endmntent(FILE *filep)
+ #include <sys/param.h>
+ #include <sys/ucred.h>
+ 
++#ifdef __OpenBSD__
++/* recent OpenBSD doesn't expose struct __sFILE anymore */
++struct __sFILE { long dummy; };
++#endif
++
+ /* A pointer to one of these is returned by mne_setmntent(), depending on which file
+ ** name is given as an input. Note that on BSD systems, the system calls themselves
+ ** deal with the reading of files, so gentoo will never in fact open any files. But

> mntent_wrap.c:112:13: error: tentative definition has type 'FILE' (aka
> 'struct __sFILE') that is
> never completed
>   112 | static FILE     f_fstab, f_mtab;
>       |                 ^
> 
> Index: patches/patch-src_mntent_wrap_c
> ===================================================================
> RCS file: patches/patch-src_mntent_wrap_c
> diff -N patches/patch-src_mntent_wrap_c
> --- /dev/null	1 Jan 1970 00:00:00 -0000
> +++ patches/patch-src_mntent_wrap_c	12 Jul 2025 14:07:11 -0000
> @@ -0,0 +1,80 @@
> +Index: src/mntent_wrap.c
> +--- src/mntent_wrap.c.orig
> ++++ src/mntent_wrap.c
> +@@ -109,7 +109,7 @@ gint mne_endmntent(FILE *filep)
> + ** of what kind of mount entries we're supposed to deal with. Since gentoo will
> + ** pass a FILE pointer to mne_getmntent() anyway, it seems natural to use it.
> + */
> +-static FILE	f_fstab, f_mtab;
> ++static FILE	*f_fstab, *f_mtab;
> + 
> + /* These are used when we're accessing the currently mounted filesystems, using
> + ** a call to getmntinfo(). The mtab_pos and mtab_num integers are then used to
> +@@ -131,29 +131,34 @@ FILE * mne_setmntent(const gchar *filename)
> + 
> + 	if(strcmp(filename, "/etc/fstab") == 0)		/* Looking for available filesystems? */
> + 	{
> +-		if(setfsent() == 1)
> +-			return &f_fstab;
> ++		if(setfsent() == 1) {
> ++			if (f_fstab == NULL)
> ++				f_fstab = fopen(filename, "r");
> ++			return f_fstab;
> ++		}
> + 	}
> + 	else if(strcmp(filename, "/proc/mtab") == 0)	/* Looking for mounted filesystems? */
> + 	{
> + 		if((mtab_num = getmntinfo(&mtab, 0)) > 0)
> + 		{
> + 			mtab_pos = 0;
> +-			return &f_mtab;
> ++			if (f_mtab == NULL)
> ++				f_mtab = fopen(filename, "r");
> ++			return f_mtab;
> + 		}
> + 	}
> + 	return NULL;
> + }
> + 
> +-/* 1999-05-09 -	Get another entry of data, either about mounted (filep == &f_mtab) or available
> +-**		(filep == &f_fstab) filesystems. Returns NULL when the respective data source
> ++/* 1999-05-09 -	Get another entry of data, either about mounted (filep == f_mtab) or available
> ++**		(filep == f_fstab) filesystems. Returns NULL when the respective data source
> + **		is exhausted.
> + */
> + const MntEnt * mne_getmntent(FILE *filep)
> + {
> + 	static MntEnt	me;
> + 
> +-	if(filep == &f_fstab)
> ++	if(filep == f_fstab)
> + 	{
> + 		struct fstab	*ment;
> + 
> +@@ -164,7 +169,7 @@ const MntEnt * mne_getmntent(FILE *filep)
> + 			return &me;
> + 		}
> + 	}
> +-	else if(filep == &f_mtab)
> ++	else if(filep == f_mtab)
> + 	{
> + 		if(mtab_pos == mtab_num)		/* Array exhausted? */
> + 			return NULL;
> +@@ -182,8 +187,16 @@ const MntEnt * mne_getmntent(FILE *filep)
> + /* 1999-05-09 -	Stop traversing mount/fs data. */
> + gint mne_endmntent(FILE *filep)
> + {
> +-	if(filep == &f_fstab)
> ++	if (filep == NULL)
> ++		return 0;
> ++	if(filep == f_fstab) {
> ++		fclose(f_fstab);
> ++		f_fstab = NULL;
> + 		endfsent();
> ++	} else if (filep == f_mtab) {
> ++		fclose(f_mtab);
> ++		f_mtab = NULL;
> ++	}
> + 
> + 	return 0;
> + }
> 
>