Date: Tue, 20 Apr 2021 19:21:45 +0100 From: Frank Leonhardt <freebsd-doc@fjl.co.uk> To: freebsd-questions@freebsd.org Subject: Bug in current versions of /usr/include/dirent.h ? Message-ID: <fa2c4f47-f8e6-7553-6fff-2454f3cac2d8@fjl.co.uk>
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Weird one this! I'm currently using 12.2, but this appears to be a
problem in recent versions.
In FreeBSD 8, dirent.h contains the following:
/* structure describing an open directory. */
typedef struct _dirdesc {
int dd_fd; /* file descriptor associated with
directory */
long dd_loc; /* offset in current buffer */
long dd_size; /* amount of data returned by
getdirentries */
char *dd_buf; /* data buffer */
int dd_len; /* size of data buffer */
long dd_seek; /* magic cookie returned by
getdirentries */
long dd_rewind; /* magic cookie for rewinding */
int dd_flags; /* flags for readdir */
struct pthread_mutex *dd_lock; /* lock */
struct _telldir *dd_td; /* telldir position recording */
} DIR;
Nothing wrong there. It's the structure used by opendir() etc in the
standard C library.
In 12.2 we've not got a structure definition, but instead a forward
reference at line 87. DIR is typedefed on the following line. However,
nowhere can I find where this forward reference is later resolved -
meaning it isn't.
Has anyone got the faintest idea what's going on? I've had a look
through the source code to see where a DIR structure is used, and it may
as well be a (void *) - it's used as a handle returned by opendir() in
subsequent operations but never dereferenced.
And before anyone questions why de-referencing it is necessary - first
off, it's always been a published structure so it's fair game.
Secondly, full access to the dd_fd field was handy. If access to this
structure is "deprecated" after 40 years, at the very least the handle
should have been typedefed into something safer than a forward reference.
So what's the sane explanation?
Thanks, Frank.
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