On 01/11/11 12:16, Jim Meyering wrote:
> save-cwd uses xgetcwd, which calls xalloc_die.
Thanks for tracking that down. How about this revised patch
instead? It also fixes the ChangeLog along the lines of your
previous email.
>From 47ea09cc55b49fa027b7f66e15cb5e70e7119ee6 Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Tue, 11 Jan 2011 10:42:55 -0800
Subject: [PATCH] openat, save-cwd: avoid xmalloc
This removes an direct (but undocumented) dependency of openat on
xalloc, along with an indirect dependency via save-cwd. It also
removes a dependency of save-cwd on xgetcwd (and thereby
indirectly) on xalloc. This change causes the openat substitute
to fall back on save_cwd when memory is tight, and for save_cwd to
fail instead of dying when memory is tight, but that's good enough.
* lib/openat-proc.c: Include stdlib.h (for malloc), not
xalloc.h (for xmalloc).
(openat_proc_name): Check for malloc failure.
* lib/save-cwd.c (save_cwd): Use getcwd, not xgetcwd.
* modules/save-cwd (Files): Remove xgetcwd.
---
ChangeLog | 10 ++++++++++
lib/openat-proc.c | 13 ++++++++++---
lib/save-cwd.c | 4 ++--
modules/save-cwd | 1 -
4 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index f8cd305..244b09b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,15 @@
2011-01-11 Paul Eggert <egg...@cs.ucla.edu>
+ openat: avoid xmalloc
+ This removes an indirect dependency on xmalloc. This change
+ causes the openat substitute to fall back on save_cwd when memory
+ is tight, but that's good enough.
+ * lib/openat-proc.c: Include stdlib.h (for malloc), not
+ xalloc.h (for xmalloc).
+ (openat_proc_name): Check for malloc failure.
+ * lib/save-cwd.c (save_cwd): Use getcwd, not xgetcwd.
+ * modules/save-cwd (Files): Remove xgetcwd.
+
openat: Increase OPENAT_BUFFER_SIZE from 512 to at least 1024
This avoids heap allocation for file names whose lengths are in
the range 512..1023, with the upper bound increasing to at most
diff --git a/lib/openat-proc.c b/lib/openat-proc.c
index 51a8aa2..34c74a7 100644
--- a/lib/openat-proc.c
+++ b/lib/openat-proc.c
@@ -26,13 +26,13 @@
#include <fcntl.h>
#include <stdio.h>
+#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "dirname.h"
#include "intprops.h"
#include "same-inode.h"
-#include "xalloc.h"
/* The results of open() in this file are not used with fchdir,
and we do not leak fds to any single-threaded code that could use stdio,
@@ -52,7 +52,8 @@
/* Set BUF to the expansion of PROC_SELF_FD_FORMAT, using FD and FILE
respectively for %d and %s. If successful, return BUF if the
result fits in BUF, dynamically allocated memory otherwise. But
- return NULL if /proc is not reliable. */
+ return NULL if /proc is not reliable, either because the operating
+ system support is lacking or because memory is low. */
char *
openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file)
{
@@ -98,7 +99,13 @@ openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char
const *file)
else
{
size_t bufsize = PROC_SELF_FD_NAME_SIZE_BOUND (strlen (file));
- char *result = (bufsize < OPENAT_BUFFER_SIZE ? buf : xmalloc (bufsize));
+ char *result = buf;
+ if (OPENAT_BUFFER_SIZE < bufsize)
+ {
+ result = malloc (bufsize);
+ if (! result)
+ return NULL;
+ }
sprintf (result, PROC_SELF_FD_FORMAT, fd, file);
return result;
}
diff --git a/lib/save-cwd.c b/lib/save-cwd.c
index be35192..099ab2e 100644
--- a/lib/save-cwd.c
+++ b/lib/save-cwd.c
@@ -54,7 +54,7 @@
/* Record the location of the current working directory in CWD so that
the program may change to other directories and later use restore_cwd
to return to the recorded location. This function may allocate
- space using malloc (via xgetcwd) or leave a file descriptor open;
+ space using malloc (via getcwd) or leave a file descriptor open;
use free_cwd to perform the necessary free or close. Upon failure,
no memory is allocated, any locally opened file descriptors are
closed; return non-zero -- in that case, free_cwd need not be
@@ -81,7 +81,7 @@ save_cwd (struct saved_cwd *cwd)
cwd->desc = fd_safer (cwd->desc);
if (cwd->desc < 0)
{
- cwd->name = xgetcwd ();
+ cwd->name = getcwd (NULL, 0);
return cwd->name ? 0 : -1;
}
diff --git a/modules/save-cwd b/modules/save-cwd
index aab5e5e..98938c3 100644
--- a/modules/save-cwd
+++ b/modules/save-cwd
@@ -11,7 +11,6 @@ chdir-long
cloexec
stdbool
unistd-safer
-xgetcwd
configure.ac:
gl_SAVE_CWD
--
1.7.3
