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authorAlexandre Oliva <oliva@adacore.com>2022-06-23 23:20:53 -0300
committerAlexandre Oliva <oliva@gnu.org>2022-06-23 23:28:14 -0300
commit93070671eae44f24ba822383e17571a39257c637 (patch)
treeec63cf8c4576857b089c6322d5e4a65c4d75d427
parent5d8a5f04acec697c893e1c2263032bc01e2c2f2b (diff)
downloadgcc-93070671eae44f24ba822383e17571a39257c637.tar.gz
libstdc++: check for openat
rtems6.0 has fdopendir, and fcntl.h defines AT_FDCWD and declares openat, but there's no openat in libc. Adjust dir-common.h to not assume ::openat just because of AT_FDCWD. for libstdc++-v3/ChangeLog * acinclude.m4 (GLIBCXX_CHECK_FILESYSTEM_DEPS): Check for openat. * configure, config.h.in: Rebuilt. * src/filesystem/dir-common.h (openat): Use ::openat if _GLIBCXX_HAVE_OPENAT. * src/filesystem/dir.cc (dir_and_pathname): Use dirfd if _GLIBCXX_HAVE_OPENAT.
-rw-r--r--libstdc++-v3/acinclude.m412
-rw-r--r--libstdc++-v3/config.h.in3
-rwxr-xr-xlibstdc++-v3/configure55
-rw-r--r--libstdc++-v3/src/filesystem/dir-common.h2
-rw-r--r--libstdc++-v3/src/filesystem/dir.cc2
5 files changed, 72 insertions, 2 deletions
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 138bd58d86c..e3cc3a8e867 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -4773,6 +4773,18 @@ dnl
AC_DEFINE(HAVE_DIRFD, 1, [Define if dirfd is available in <dirent.h>.])
fi
dnl
+ AC_CACHE_CHECK([for openat],
+ glibcxx_cv_openat, [dnl
+ GCC_TRY_COMPILE_OR_LINK(
+ [#include <fcntl.h>],
+ [int fd = ::openat(AT_FDCWD, "", 0);],
+ [glibcxx_cv_openat=yes],
+ [glibcxx_cv_openat=no])
+ ])
+ if test $glibcxx_cv_openat = yes; then
+ AC_DEFINE(HAVE_OPENAT, 1, [Define if openat is available in <fcntl.h>.])
+ fi
+dnl
AC_CACHE_CHECK([for unlinkat],
glibcxx_cv_unlinkat, [dnl
GCC_TRY_COMPILE_OR_LINK(
diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index f30a8c51c45..2a3972eef54 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -292,6 +292,9 @@
/* Define if <math.h> defines obsolete isnan function. */
#undef HAVE_OBSOLETE_ISNAN
+/* Define if openat is available in <fcntl.h>. */
+#undef HAVE_OPENAT
+
/* Define if poll is available in <poll.h>. */
#undef HAVE_POLL
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 9b94fd71e42..eac60392121 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -77178,6 +77178,61 @@ $as_echo "$glibcxx_cv_dirfd" >&6; }
$as_echo "#define HAVE_DIRFD 1" >>confdefs.h
fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking for openat" >&5
+$as_echo_n "checking for openat... " >&6; }
+if ${glibcxx_cv_openat+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ if test x$gcc_no_link = xyes; then
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+#include <fcntl.h>
+int
+main ()
+{
+int fd = ::openat(AT_FDCWD, "", 0);
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_compile "$LINENO"; then :
+ glibcxx_cv_openat=yes
+else
+ glibcxx_cv_openat=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+else
+ if test x$gcc_no_link = xyes; then
+ as_fn_error $? "Link tests are not allowed after GCC_NO_EXECUTABLES." "$LINENO" 5
+fi
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+#include <fcntl.h>
+int
+main ()
+{
+int fd = ::openat(AT_FDCWD, "", 0);
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"; then :
+ glibcxx_cv_openat=yes
+else
+ glibcxx_cv_openat=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_openat" >&5
+$as_echo "$glibcxx_cv_openat" >&6; }
+ if test $glibcxx_cv_openat = yes; then
+
+$as_echo "#define HAVE_OPENAT 1" >>confdefs.h
+
+ fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for unlinkat" >&5
$as_echo_n "checking for unlinkat... " >&6; }
if ${glibcxx_cv_unlinkat+:} false; then :
diff --git a/libstdc++-v3/src/filesystem/dir-common.h b/libstdc++-v3/src/filesystem/dir-common.h
index 365fd527f4d..669780ea23f 100644
--- a/libstdc++-v3/src/filesystem/dir-common.h
+++ b/libstdc++-v3/src/filesystem/dir-common.h
@@ -199,7 +199,7 @@ struct _Dir_base
#endif
-#ifdef AT_FDCWD
+#if _GLIBCXX_HAVE_OPENAT && defined AT_FDCWD
fd = ::openat(fd, pathname, flags);
#else
// If we cannot use openat, there's no benefit to using posix::open unless
diff --git a/libstdc++-v3/src/filesystem/dir.cc b/libstdc++-v3/src/filesystem/dir.cc
index b451902c4a1..e64489162e5 100644
--- a/libstdc++-v3/src/filesystem/dir.cc
+++ b/libstdc++-v3/src/filesystem/dir.cc
@@ -120,7 +120,7 @@ struct fs::_Dir : std::filesystem::_Dir_base
dir_and_pathname() const noexcept
{
const fs::path& p = entry.path();
-#if _GLIBCXX_HAVE_DIRFD
+#if _GLIBCXX_HAVE_DIRFD && _GLIBCXX_HAVE_OPENAT
return {::dirfd(this->dirp), std::prev(p.end())->c_str()};
#endif
return {this->fdcwd(), p.c_str()};