[Patch] associate a deallocation for opendir

[Patch] associate a deallocation for opendir

[Steve Grubb]

This patch associates closedir as a deallocation for opendir and fdopendir.
This required moving the closedir declaration above the other 2 functions.

---
 dirent.h |   20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)
---
diff -urp glibc-2.35.9000-111-g2bbc694df2.orig/dirent/dirent.h glibc-2.35.9000-111-g2bbc694df2/dirent/dirent.h
--- glibc-2.35.9000-111-g2bbc694df2.orig/dirent/dirent.h	2022-02-28 10:47:38.000000000 -0500
+++ glibc-2.35.9000-111-g2bbc694df2/dirent/dirent.h	2022-03-11 14:37:57.828733684 -0500
@@ -126,28 +126,30 @@ enum
    The actual structure is opaque to users.  */
 typedef struct __dirstream DIR;
 
+/* Close the directory stream DIRP.
+   Return 0 if successful, -1 if not.
+
+   This function is a possible cancellation point and therefore not
+   marked with __THROW.  */
+extern int closedir (DIR *__dirp) __nonnull ((1));
+
 /* Open a directory stream on NAME.
    Return a DIR stream on the directory, or NULL if it could not be opened.
 
    This function is a possible cancellation point and therefore not
    marked with __THROW.  */
-extern DIR *opendir (const char *__name) __nonnull ((1));
+extern DIR *opendir (const char *__name) __nonnull ((1))
+	__attribute_malloc__ __attr_dealloc (closedir, 1);
 
 #ifdef __USE_XOPEN2K8
 /* Same as opendir, but open the stream on the file descriptor FD.
 
    This function is a possible cancellation point and therefore not
    marked with __THROW.  */
-extern DIR *fdopendir (int __fd);
+extern DIR *fdopendir (int __fd)
+	__attribute_malloc__ __attr_dealloc (closedir, 1);
 #endif
 
-/* Close the directory stream DIRP.
-   Return 0 if successful, -1 if not.
-
-   This function is a possible cancellation point and therefore not
-   marked with __THROW.  */
-extern int closedir (DIR *__dirp) __nonnull ((1));
-
 /* Read a directory entry from DIRP.  Return a pointer to a `struct
    dirent' describing the entry, or NULL for EOF or error.  The
    storage returned may be overwritten by a later readdir call on the

Re: [Patch] associate a deallocation for opendir

[Paul Eggert]

Thanks, this patch looks good.

FWIW Gnulib/lib/dirent.in.h has been doing something similar since 
August and we haven't run into problems.

Re: [Patch] associate a deallocation for opendir

[Siddhesh Poyarekar]

LGTM too.  I'll push once I finish testing it.

Reviewed-by: Paul Eggert <eggert@cs.ucla.edu>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>


On 12/03/2022 01:59, Steve Grubb via Libc-alpha wrote:
> This patch associates closedir as a deallocation for opendir and fdopendir.
> This required moving the closedir declaration above the other 2 functions.
> 
> ---
>   dirent.h |   20 +++++++++++---------
>   1 file changed, 11 insertions(+), 9 deletions(-)
> ---
> diff -urp glibc-2.35.9000-111-g2bbc694df2.orig/dirent/dirent.h glibc-2.35.9000-111-g2bbc694df2/dirent/dirent.h
> --- glibc-2.35.9000-111-g2bbc694df2.orig/dirent/dirent.h	2022-02-28 10:47:38.000000000 -0500
> +++ glibc-2.35.9000-111-g2bbc694df2/dirent/dirent.h	2022-03-11 14:37:57.828733684 -0500
> @@ -126,28 +126,30 @@ enum
>      The actual structure is opaque to users.  */
>   typedef struct __dirstream DIR;
>   
> +/* Close the directory stream DIRP.
> +   Return 0 if successful, -1 if not.
> +
> +   This function is a possible cancellation point and therefore not
> +   marked with __THROW.  */
> +extern int closedir (DIR *__dirp) __nonnull ((1));
> +
>   /* Open a directory stream on NAME.
>      Return a DIR stream on the directory, or NULL if it could not be opened.
>   
>      This function is a possible cancellation point and therefore not
>      marked with __THROW.  */
> -extern DIR *opendir (const char *__name) __nonnull ((1));
> +extern DIR *opendir (const char *__name) __nonnull ((1))
> +	__attribute_malloc__ __attr_dealloc (closedir, 1);
>   
>   #ifdef __USE_XOPEN2K8
>   /* Same as opendir, but open the stream on the file descriptor FD.
>   
>      This function is a possible cancellation point and therefore not
>      marked with __THROW.  */
> -extern DIR *fdopendir (int __fd);
> +extern DIR *fdopendir (int __fd)
> +	__attribute_malloc__ __attr_dealloc (closedir, 1);
>   #endif
>   
> -/* Close the directory stream DIRP.
> -   Return 0 if successful, -1 if not.
> -
> -   This function is a possible cancellation point and therefore not
> -   marked with __THROW.  */
> -extern int closedir (DIR *__dirp) __nonnull ((1));
> -
>   /* Read a directory entry from DIRP.  Return a pointer to a `struct
>      dirent' describing the entry, or NULL for EOF or error.  The
>      storage returned may be overwritten by a later readdir call on the
> 
> 
>