From 357e1c26576e584fbc24b72798d2f7cf70bd9867 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Thu, 22 Sep 2005 23:30:37 +0000 Subject: [PATCH] * modules/openat (Files): Add lib/openat-die.c. (Depends-on): Remove error, exitfail. Add dirname. * lib/openat.c (fdopendir): Be sure to close the supplied file descriptor before returning. This makes our replacement implementation a little closer to Solaris's, where fdopendir ties the file descriptor to the returned DIR* pointer. * lib/openat.c (unlinkat): New function. * lib/openat.h (unlinkat): Add prototype. * lib/openat-die.c (openat_save_fail): Rename from openat_save_die. (openat_restore_fail): Rename from openat_restore_die. * lib/openat.c, openat.h: Reflect s/_die/_fail/ renaming. Provide an alternative to exiting immediately upon save_cwd or restore_cwd failure. Now, an application can arrange e.g., to perform a longjump in that case. * lib/openat.c: Include dirname.h. Use IS_ABSOLUTE_FILE_NAME rather than testing for leading slash. (rpl_openat, fdopendir, fstatat): Call openat_save_die and openat_restore_die rather than calling error directly. Don't include "error.h" or "exitfail.h"; they're no longer needed. * lib/openat-die.c (openat_save_die, openat_restore_die): New file. * lib/openat.h (openat_save_die, openat_restore_die): Declare and define. * m4/openat.m4 (gl_FUNC_OPENAT): Add openat-die.c. --- lib/openat-die.c | 53 +++++++++++++++++++++++++++++++++++++++++ lib/openat.c | 72 +++++++++++++++++++++++++++++++++++++++++++------------- lib/openat.h | 22 +++++++++++++++-- m4/openat.m4 | 7 +++--- modules/openat | 4 ++-- 5 files changed, 135 insertions(+), 23 deletions(-) create mode 100644 lib/openat-die.c diff --git a/lib/openat-die.c b/lib/openat-die.c new file mode 100644 index 000000000..f7cc15dbc --- /dev/null +++ b/lib/openat-die.c @@ -0,0 +1,53 @@ +/* Report a save- or restore-cwd failure in our openat replacement and then exit. + + Copyright (C) 2005 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2, or (at your option) + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + +#if HAVE_CONFIG_H +# include +#endif + +#include + +#include "error.h" +#include "exitfail.h" + +#include "gettext.h" +#define _(msgid) gettext (msgid) +#define N_(msgid) msgid + +void +openat_save_fail (int errno) +{ + error (exit_failure, errno, + _("unable to record current working directory")); + + /* The `noreturn' attribute cannot be applied to error, since it returns + when its first argument is 0. To help compilers understand that this + function does not return, call abort. Also, the abort is a + safety feature if exit_failure is 0 (which shouldn't happen). */ + abort (); +} + +void +openat_restore_fail (int errno) +{ + error (exit_failure, errno, + _("failed to return to initial working directory")); + + /* As above. */ + abort (); +} diff --git a/lib/openat.c b/lib/openat.c index 443cb3da6..f7eb39d0e 100644 --- a/lib/openat.c +++ b/lib/openat.c @@ -29,8 +29,7 @@ #include #include -#include "error.h" -#include "exitfail.h" +#include "dirname.h" /* solely for definition of IS_ABSOLUTE_FILE_NAME */ #include "save-cwd.h" #include "gettext.h" @@ -64,12 +63,11 @@ rpl_openat (int fd, char const *file, int flags, ...) va_end (arg); } - if (fd == AT_FDCWD || *file == '/') + if (fd == AT_FDCWD || IS_ABSOLUTE_FILE_NAME (file)) return open (file, flags, mode); if (save_cwd (&saved_cwd) != 0) - error (exit_failure, errno, - _("openat: unable to record current working directory")); + openat_save_fail (errno); if (fchdir (fd) != 0) { @@ -83,8 +81,7 @@ rpl_openat (int fd, char const *file, int flags, ...) saved_errno = errno; if (restore_cwd (&saved_cwd) != 0) - error (exit_failure, errno, - _("openat: unable to restore working directory")); + openat_restore_fail (errno); free_cwd (&saved_cwd); @@ -98,7 +95,12 @@ rpl_openat (int fd, char const *file, int flags, ...) If either the save_cwd or the restore_cwd fails (relatively unlikely, and usually indicative of a problem that deserves close attention), then give a diagnostic and exit nonzero. - Otherwise, this function works just like Solaris' fdopendir. */ + Otherwise, this function works just like Solaris' fdopendir. + + W A R N I N G: + Unlike the other fd-related functions here, this one + effectively consumes its FD parameter. The caller should not + close or otherwise manipulate FD after calling this function. */ DIR * fdopendir (int fd) { @@ -110,13 +112,13 @@ fdopendir (int fd) return opendir ("."); if (save_cwd (&saved_cwd) != 0) - error (exit_failure, errno, - _("fdopendir: unable to record current working directory")); + openat_save_fail (errno); if (fchdir (fd) != 0) { saved_errno = errno; free_cwd (&saved_cwd); + close (fd); errno = saved_errno; return NULL; } @@ -125,10 +127,10 @@ fdopendir (int fd) saved_errno = errno; if (restore_cwd (&saved_cwd) != 0) - error (exit_failure, errno, - _("fdopendir: unable to restore working directory")); + openat_restore_fail (errno); free_cwd (&saved_cwd); + close (fd); errno = saved_errno; return dir; @@ -154,8 +156,7 @@ fstatat (int fd, char const *file, struct stat *st, int flag) : stat (file, st)); if (save_cwd (&saved_cwd) != 0) - error (exit_failure, errno, - _("fstatat: unable to record current working directory")); + openat_save_fail (errno); if (fchdir (fd) != 0) { @@ -171,8 +172,47 @@ fstatat (int fd, char const *file, struct stat *st, int flag) saved_errno = errno; if (restore_cwd (&saved_cwd) != 0) - error (exit_failure, errno, - _("fstatat: unable to restore working directory")); + openat_restore_fail (errno); + + free_cwd (&saved_cwd); + + errno = saved_errno; + return err; +} + +/* Replacement for Solaris' function by the same name. + + Simulate it by doing save_cwd/fchdir/(unlink|rmdir)/restore_cwd. + If either the save_cwd or the restore_cwd fails (relatively unlikely, + and usually indicative of a problem that deserves close attention), + then give a diagnostic and exit nonzero. + Otherwise, this function works just like Solaris' unlinkat. */ +int +unlinkat (int fd, char const *file, int flag) +{ + struct saved_cwd saved_cwd; + int saved_errno; + int err; + + if (fd == AT_FDCWD) + return (flag == AT_REMOVEDIR ? rmdir (file) : unlink (file)); + + if (save_cwd (&saved_cwd) != 0) + openat_save_fail (errno); + + if (fchdir (fd) != 0) + { + saved_errno = errno; + free_cwd (&saved_cwd); + errno = saved_errno; + return -1; + } + + err = (flag == AT_REMOVEDIR ? rmdir (file) : unlink (file)); + saved_errno = errno; + + if (restore_cwd (&saved_cwd) != 0) + openat_restore_fail (errno); free_cwd (&saved_cwd); diff --git a/lib/openat.h b/lib/openat.h index 76ad46bdb..5aa693c4d 100644 --- a/lib/openat.h +++ b/lib/openat.h @@ -24,9 +24,20 @@ #include #include +#ifndef __attribute__ +# if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__ +# define __attribute__(x) /* empty */ +# endif +#endif + +#ifndef ATTRIBUTE_NORETURN +# define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__)) +#endif + #ifndef AT_FDCWD -# define AT_FDCWD (-3041965) /* same value as Solaris 9 */ -# define AT_SYMLINK_NOFOLLOW 4096 /* same value as Solaris 9 */ +# define AT_FDCWD (-3041965) /* same value as Solaris 9 */ +# define AT_SYMLINK_NOFOLLOW 4096 /* same value as Solaris 9 */ +# define AT_REMOVEDIR (0x1) /* same value as Solaris 9 */ # ifdef __OPENAT_PREFIX # undef openat @@ -39,6 +50,13 @@ int openat (int fd, char const *file, int flags, /* mode_t mode */ ...); DIR *fdopendir (int fd); # define fstatat __OPENAT_ID (fstatat) int fstatat (int fd, char const *file, struct stat *st, int flag); +# define unlinkat __OPENAT_ID (unlinkat) +int unlinkat (int fd, char const *file, int flag); +void openat_restore_fail (int) ATTRIBUTE_NORETURN; +void openat_save_fail (int) ATTRIBUTE_NORETURN; +# else +# define openat_restore_fail(Errno) /* empty */ +# define openat_save_fail(Errno) /* empty */ # endif #endif diff --git a/m4/openat.m4 b/m4/openat.m4 index 27b0e59e6..0f0156e95 100644 --- a/m4/openat.m4 +++ b/m4/openat.m4 @@ -1,7 +1,7 @@ -#serial 3 +#serial 4 # See if we need to use our replacement for Solaris' openat function. -dnl Copyright (C) 2004 Free Software Foundation, Inc. +dnl Copyright (C) 2004, 2005 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. @@ -10,7 +10,8 @@ dnl with or without modifications, as long as this notice is preserved. AC_DEFUN([gl_FUNC_OPENAT], [ - AC_LIBSOURCES([openat.c, openat.h]) + AC_LIBSOURCES([openat.c, openat.h, openat-die.c]) + AC_LIBOBJ([openat-die]) AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) AC_REPLACE_FUNCS(openat) case $ac_cv_func_openat in diff --git a/modules/openat b/modules/openat index 69eff3b3d..9db293703 100644 --- a/modules/openat +++ b/modules/openat @@ -4,13 +4,13 @@ Open a file at a directory. Files: lib/openat.c lib/openat.h +lib/openat-die.c m4/openat.m4 Depends-on: save-cwd gettext-h -error -exitfail +dirname extensions configure.ac: -- 2.11.0