X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fopenat.m4;h=5683650d0f9fc57c5849c5392e367f1edd277ef2;hb=de1fa2ac9aeb9f70a042ee3faa2b7712e65a278b;hp=fca3bd06171f9a23a22a31377ab4afe68ebbba9a;hpb=75ff6c9d9a4d428c44dbbd8778f0e8080a0d3bdc;p=gnulib.git diff --git a/m4/openat.m4 b/m4/openat.m4 index fca3bd061..5683650d0 100644 --- a/m4/openat.m4 +++ b/m4/openat.m4 @@ -1,7 +1,7 @@ -#serial 11 +# serial 35 # See if we need to use our replacement for Solaris' openat et al functions. -dnl Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc. +dnl Copyright (C) 2004-2011 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. @@ -10,26 +10,168 @@ dnl with or without modifications, as long as this notice is preserved. AC_DEFUN([gl_FUNC_OPENAT], [ - # No system provides these functions; compile them unconditionally. - AC_LIBOBJ([mkdirat]) - AC_LIBOBJ([fchmodat]) + AC_REQUIRE([gl_FCNTL_H_DEFAULTS]) + GNULIB_OPENAT=1 + + AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS]) + GNULIB_FCHMODAT=1 + GNULIB_FSTATAT=1 + GNULIB_MKDIRAT=1 + + AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) + GNULIB_FCHOWNAT=1 + GNULIB_UNLINKAT=1 - AC_LIBOBJ([openat-die]) - AC_LIBOBJ([openat-proc]) AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) - AC_CHECK_FUNCS_ONCE([lchmod]) - AC_CHECK_FUNCS_ONCE([fdopendir]) - AC_REPLACE_FUNCS(openat) - case $ac_cv_func_openat in - yes) ;; + AC_CHECK_FUNCS_ONCE([fchmodat lchmod mkdirat openat unlinkat]) + AC_REQUIRE([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK]) + AC_REQUIRE([gl_FUNC_UNLINK]) + case $ac_cv_func_openat+$gl_cv_func_lstat_dereferences_slashed_symlink in + yes+yes) + # GNU/Hurd has unlinkat, but it has the same bug as unlink. + if test $REPLACE_UNLINK = 1; then + REPLACE_UNLINKAT=1 + fi ;; + yes+*) + # Solaris 9 has *at functions, but uniformly mishandles trailing + # slash in all of them. + REPLACE_OPENAT=1 + REPLACE_UNLINKAT=1 + ;; *) - AC_DEFINE([__OPENAT_PREFIX], [[rpl_]], - [Define to rpl_ if the openat replacement function should be used.]) + HAVE_OPENAT=0 + HAVE_UNLINKAT=0 # No known system with unlinkat but not openat gl_PREREQ_OPENAT;; esac + if test $ac_cv_func_fchmodat != yes; then + HAVE_FCHMODAT=0 + fi + if test $ac_cv_func_mkdirat != yes; then + HAVE_MKDIRAT=0 + fi + gl_FUNC_FCHOWNAT + gl_FUNC_FSTATAT +]) + +# gl_FUNC_FCHOWNAT_DEREF_BUG([ACTION-IF-BUGGY[, ACTION-IF-NOT_BUGGY]]) +AC_DEFUN([gl_FUNC_FCHOWNAT_DEREF_BUG], +[ + dnl Persuade glibc's to declare fchownat(). + AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) + + AC_CACHE_CHECK([whether fchownat works with AT_SYMLINK_NOFOLLOW], + gl_cv_func_fchownat_nofollow_works, + [ + gl_dangle=conftest.dangle + # Remove any remnants of a previous test. + rm -f $gl_dangle + # Arrange for deletion of the temporary file this test creates. + ac_clean_files="$ac_clean_files $gl_dangle" + ln -s conftest.no-such $gl_dangle + AC_RUN_IFELSE( + [AC_LANG_SOURCE( + [[ +#include +#include +#include +#include +#include +int +main () +{ + return (fchownat (AT_FDCWD, "$gl_dangle", -1, getgid (), + AT_SYMLINK_NOFOLLOW) != 0 + && errno == ENOENT); +} + ]])], + [gl_cv_func_fchownat_nofollow_works=yes], + [gl_cv_func_fchownat_nofollow_works=no], + [gl_cv_func_fchownat_nofollow_works=no], + ) + ]) + AS_IF([test $gl_cv_func_fchownat_nofollow_works = no], [$1], [$2]) +]) + +# gl_FUNC_FCHOWNAT_EMPTY_FILENAME_BUG([ACTION-IF-BUGGY[, ACTION-IF-NOT_BUGGY]]) +AC_DEFUN([gl_FUNC_FCHOWNAT_EMPTY_FILENAME_BUG], +[ + dnl Persuade glibc's to declare fchownat(). + AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) + + AC_CACHE_CHECK([whether fchownat works with an empty file name], + [gl_cv_func_fchownat_empty_filename_works], + [AC_RUN_IFELSE( + [AC_LANG_PROGRAM( + [[#include + #include + ]], + [[int fd; + int ret; + if (mkdir ("conftestdir", 0700) < 0) + return 2; + fd = open ("conftestdir", O_RDONLY); + if (fd < 0) + return 3; + ret = fchownat (fd, "", -1, -1, 0); + close (fd); + rmdir ("conftestdir"); + return ret == 0; + ]])], + [gl_cv_func_fchownat_empty_filename_works=yes], + [gl_cv_func_fchownat_empty_filename_works=no], + [gl_cv_func_fchownat_empty_filename_works="guessing no"]) + ]) + AS_IF([test "$gl_cv_func_fchownat_empty_filename_works" != yes], [$1], [$2]) +]) + +# If we have the fchownat function, and it has the bug (in glibc-2.4) +# that it dereferences symlinks even with AT_SYMLINK_NOFOLLOW, then +# use the replacement function. +# Also if the fchownat function, like chown, has the trailing slash bug, +# use the replacement function. +# Also use the replacement function if fchownat is simply not available. +AC_DEFUN([gl_FUNC_FCHOWNAT], +[ + AC_REQUIRE([gl_UNISTD_H_DEFAULTS]) + AC_REQUIRE([gl_FUNC_CHOWN]) + AC_CHECK_FUNC([fchownat], + [gl_FUNC_FCHOWNAT_DEREF_BUG( + [REPLACE_FCHOWNAT=1 + AC_DEFINE([FCHOWNAT_NOFOLLOW_BUG], [1], + [Define to 1 if your platform has fchownat, but it cannot + perform lchown tasks.]) + ]) + gl_FUNC_FCHOWNAT_EMPTY_FILENAME_BUG( + [REPLACE_FCHOWNAT=1 + AC_DEFINE([FCHOWNAT_EMPTY_FILENAME_BUG], [1], + [Define to 1 if your platform has fchownat, but it does + not reject an empty file name.]) + ]) + if test $REPLACE_CHOWN = 1; then + REPLACE_FCHOWNAT=1 + fi], + [HAVE_FCHOWNAT=0]) +]) + +# If we have the fstatat function, and it has the bug (in AIX 7.1) +# that it does not fill in st_size correctly, use the replacement function. +AC_DEFUN([gl_FUNC_FSTATAT], +[ + AC_REQUIRE([gl_SYS_STAT_H_DEFAULTS]) + AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) + AC_REQUIRE([gl_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK]) + AC_CHECK_FUNCS_ONCE([fstatat]) + + if test $ac_cv_func_fstatat = no; then + HAVE_FSTATAT=0 + elif test $gl_cv_func_lstat_dereferences_slashed_symlink != yes; then + REPLACE_FSTATAT=1 + fi ]) AC_DEFUN([gl_PREREQ_OPENAT], [ - AC_REQUIRE([gl_SAVE_CWD]) + AC_REQUIRE([AC_C_INLINE]) + AC_REQUIRE([gl_PROMOTED_TYPE_MODE_T]) + : ])