Oops, that message got bounced from the lists and was the wrong
version of the patch anyway - this is the one I meant to attach.
On Sun, 17 Jun 2018 at 00:00, Jonathan Wakely <[email protected]> wrote:
>
> Here's what I wanted to test, which removes the new AC_CHECK_FUNCS (replacing
> them with GLIBCXX_COMPILE_OR_LINK tests that shouldn't even get run on bare
> metal ).
>
>
>
> On Sat, 16 Jun 2018 at 23:39, Jonathan Wakely <[email protected]> wrote:
>>
>>
>>
>> On Sat, 16 Jun 2018 at 14:06, Jonathan Wakely <[email protected]> wrote:
>>>
>>>
>>>
>>> On Sat, 16 Jun 2018 at 02:04, Sandra Loosemore <[email protected]>
>>> wrote:
>>>>
>>>> On 05/31/2018 01:19 PM, Jonathan Wakely wrote:
>>>> > This adds incomplete but functional support for std::filesystem and
>>>> > std::experimental::filesystem on MinGW. In theory there should be no
>>>> > changes to the existing behaviour for POSIX targets from this patch,
>>>> > as all the various bugs I found while working on this have already
>>>> > been fixed in separate patches.
>>>> >
>>>> > Tested powerpc64le-linux, and x86_64-w64-mingw32 (with a few expected
>>>> > FAILures on mingw-w64). Committed to trunk.
>>>>
>>>> As noted in the issue (comment #16) 2 weeks ago already, this patch
>>>> breaks libstdc++ configure on bare-metal targets.
>>>>
>>>> configure:80055: checking for link
>>>> configure:80055: error: Link tests are not allowed after
>>>> GCC_NO_EXECUTABLES.
>>>>
>>>> Please fix? It's blocking other people from testing unrelated patches
>>>> on mainline.
>>>>
>>>
>>>
>>> I'm not the only person able to make changes to autoconf files (and already
>>> said I didn't know how to fix this).
>>>
>>> I have a patch to replace the AC_CHECK_FUNCS line with
>>> GLIBCXX_COMPILE_OR_LINK tests inside GLIBCXX_CHECK_FILESYSTEM_DEPS which
>>> should work, I'll finish testing it when I get home this evening.
>>>
>>
>> I can't build aarch64-none-elf even before my commit, so I also can't test a
>> fix.
>>
>> checking for shl_load... configure: error: Link tests are not allowed after
>> GCC_NO_EXECUTABLES.
>>
>>
>>
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 4f37b6a6498..62b42d203e9 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -4314,6 +4314,7 @@ dnl and define _GLIBCXX_USE_REALPATH and
_GLIBCXX_USE_UTIMENSAT.
dnl
AC_DEFUN([GLIBCXX_CHECK_FILESYSTEM_DEPS], [dnl
dnl
+ if test $enable_libstdcxx_filesystem_ts = yes; then
AC_LANG_SAVE
AC_LANG_CPLUSPLUS
ac_save_CXXFLAGS="$CXXFLAGS"
@@ -4443,9 +4444,49 @@ dnl
AC_DEFINE(_GLIBCXX_USE_SENDFILE, 1, [Define if sendfile is available in
<sys/sendfile.h>.])
fi
AC_MSG_RESULT($glibcxx_cv_sendfile)
+dnl
+ AC_MSG_CHECKING([for link])
+ AC_CACHE_VAL(glibcxx_cv_link, [dnl
+ GCC_TRY_COMPILE_OR_LINK(
+ [#include <unistd.h>],
+ [link("", "");],
+ [glibcxx_cv_link=yes],
+ [glibcxx_cv_link=no])
+ ])
+ if test $glibcxx_cv_link = yes; then
+ AC_DEFINE(HAVE_LINK, 1, [Define if link is available in <unistd.h>.])
+ fi
+ AC_MSG_RESULT($glibcxx_cv_link)
+dnl
+ AC_MSG_CHECKING([for readlink])
+ AC_CACHE_VAL(glibcxx_cv_readlink, [dnl
+ GCC_TRY_COMPILE_OR_LINK(
+ [#include <unistd.h>],
+ [char buf[32]; readlink("", buf, sizeof(buf));],
+ [glibcxx_cv_readlink=yes],
+ [glibcxx_cv_readlink=no])
+ ])
+ if test $glibcxx_cv_readlink = yes; then
+ AC_DEFINE(HAVE_READLINK, 1, [Define if readlink is available in
<unistd.h>.])
+ fi
+ AC_MSG_RESULT($glibcxx_cv_readlink)
+dnl
+ AC_MSG_CHECKING([for symlink])
+ AC_CACHE_VAL(glibcxx_cv_symlink, [dnl
+ GCC_TRY_COMPILE_OR_LINK(
+ [#include <unistd.h>],
+ [symlink("", "");],
+ [glibcxx_cv_symlink=yes],
+ [glibcxx_cv_symlink=no])
+ ])
+ if test $glibcxx_cv_symlink = yes; then
+ AC_DEFINE(HAVE_SYMLINK, 1, [Define if symlink is available in <unistd.h>.])
+ fi
+ AC_MSG_RESULT($glibcxx_cv_symlink)
dnl
CXXFLAGS="$ac_save_CXXFLAGS"
AC_LANG_RESTORE
+ fi
])
dnl
diff --git a/libstdc++-v3/configure.ac b/libstdc++-v3/configure.ac
index dde1c4da944..7e1fd84606a 100644
--- a/libstdc++-v3/configure.ac
+++ b/libstdc++-v3/configure.ac
@@ -420,7 +420,6 @@ GLIBCXX_CHECK_GTHREADS
# For Filesystem TS.
AC_CHECK_HEADERS([fcntl.h dirent.h sys/statvfs.h utime.h])
-AC_CHECK_FUNCS(link readlink symlink)
GLIBCXX_ENABLE_FILESYSTEM_TS
GLIBCXX_CHECK_FILESYSTEM_DEPS
