Re: [PATCH 2/2] PR libstdc++/86756 Move rest of std::filesystem to libstdc++.so

[Christophe Lyon <christophe.lyon@linaro.org>]

On Wed, 9 Jan 2019 at 11:11, Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On 09/01/19 10:09 +0000, Jonathan Wakely wrote:
> >On 08/01/19 11:13 +0100, Christophe Lyon wrote:
> >>On Mon, 7 Jan 2019 at 15:14, Christophe Lyon <christophe.lyon@linaro.org> wrote:
> >>>
> >>>On Mon, 7 Jan 2019 at 13:39, Jonathan Wakely <jwakely@redhat.com> wrote:
> >>>>
> >>>> On 07/01/19 09:48 +0000, Jonathan Wakely wrote:
> >>>> >On 07/01/19 10:24 +0100, Christophe Lyon wrote:
> >>>> >>Hi Jonathan
> >>>> >>
> >>>> >>On Sun, 6 Jan 2019 at 23:37, Jonathan Wakely <jwakely@redhat.com> wrote:
> >>>> >>>
> >>>> >>>Move std::filesystem directory iterators and operations from
> >>>> >>>libstdc++fs.a to main libstdc++ library. These components have many
> >>>> >>>dependencies on OS support, which is not available on all targets. Some
> >>>> >>>additional autoconf checks and conditional compilation is needed to
> >>>> >>>ensure the files will build for all targets. Previously this code was
> >>>> >>>not compiled without --enable-libstdcxx-filesystem-ts but the C++17
> >>>> >>>components should be available for all hosted builds.
> >>>> >>>
> >>>> >>>The tests for these components no longer need to link to libstdc++fs.a,
> >>>> >>>but are not expected to pass on all targets. To avoid numerous failures
> >>>> >>>on targets which are not expected to pass the tests (due to missing OS
> >>>> >>>functionality) leave the dg-require-filesystem-ts directives in place
> >>>> >>>for now. This will ensure the tests only run for builds where the
> >>>> >>>filesystem-ts library is built, which presumably means some level of OS
> >>>> >>>support is present.
> >>>> >>>
> >>>> >>>
> >>>> >>>Tested x86_64-linux (old/new string ABIs, 32/64 bit), x86_64-w64-mingw32.
> >>>> >>>
> >>>> >>>Committed to trunk.
> >>>> >>>
> >>>> >>
> >>>> >>After this commit (r267616), I've noticed build failures for my
> >>>> >>newlib-based toolchains:
> >>>> >>aarch64-elf, arm-eabi:
> >>>> >>
> >>>> >>In file included from
> >>>> >>/tmp/5241593_7.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/libstdc++-v3/src/c++17/fs_ops.cc:57:
> >>>> >>/tmp/5241593_7.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/libstdc++-v3/src/c++17/../filesystem/ops-common.h:142:11:
> >>>> >>error: '::truncate' has not been declared
> >>>> >> 142 |   using ::truncate;
> >>>> >>     |           ^~~~~~~~
> >>>> >>/tmp/5241593_7.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/libstdc++-v3/src/c++17/fs_ops.cc:
> >>>> >>In function 'void std::filesystem::resize_file(const
> >>>> >>std::filesystem::__cxx11::path&, uintmax_t, std::error_code&)':
> >>>> >>/tmp/5241593_7.tmpdir/aci-gcc-fsf/sources/gcc-fsf/gccsrc/libstdc++-v3/src/c++17/fs_ops.cc:1274:19:
> >>>> >>error: 'truncate' is not a member of 'posix'
> >>>> >>1274 |   else if (posix::truncate(p.c_str(), size))
> >>>> >>     |                   ^~~~~~~~
> >>>> >>make[5]: *** [fs_ops.lo] Error 1
> >>>> >>
> >>>> >>I'm not sure if there's an obvious fix? Note that I'm using a rather
> >>>> >>old newlib version, if that matters.
> >>>> >
> >>>> >That's probably the reason, as I didn't see this in my tests with
> >>>> >newlib builds.
> >>>> >
> >>>> >The fix is to add yet another autoconf check and guard the uses of
> >>>> >truncate with a _GLIBCXX_USE_TRUNCATE macro. I'll do that now ...
> >>>>
> >>>>
> >>>> Should be fixed with this patch, committed to trunk as r267647.
> >>>>
> >>>
> >>>Yes, it works. Thanks!
> >>>
> >>
> >>Hi Jonathan,
> >>
> >>So... this was a confirmation that the GCC build succeeded, not that
> >>the tests pass :)
> >>
> >>And there are actually a couple new errors with my newlib-based toolchains:
> >>FAIL: 27_io/filesystem/operations/all.cc (test for excess errors)
> >>FAIL: 27_io/filesystem/operations/resize_file.cc (test for excess errors)
> >>FAIL: 27_io/filesystem/path/generation/normal2.cc (test for excess errors)
> >>which are also UNRESOLVED, because of link-time undefined reference to `chdir',
> >>chmod, mkdir, pathconf and getcwd.
> >
> >Ah, I was assuming if <unistd.h> is present, then those basic
> >functions will be present. More autoconf checks needed, I guess.
> >That isn't hard to do, just tedious.
> >
> >>On aarch64, I'm seeing an addtional:
> >>FAIL: 27_io/filesystem/path/compare/strings.cc execution test
> >>because:
> >>/libstdc++-v3/testsuite/27_io/filesystem/path/compare/strings.cc:39:
> >>void test01(): Assertion 'p.compare(p0) == p.compare(s0)' failed.
> >
> >Odd, I don't know why that would be target-specific. It's probably
> >just latent on other targets. I'll try to reproduce it on my aarch64
> >system, but it will take a while to build current trunk.
> >
> >If you have time, could you please apply this patch, re-run that test
>
> *This* patch:
>
> --- a/libstdc++-v3/testsuite/27_io/filesystem/path/compare/strings.cc
> +++ b/libstdc++-v3/testsuite/27_io/filesystem/path/compare/strings.cc
> @@ -36,6 +36,7 @@ test01()
>      path p(s);
>      VERIFY( p.compare(s) == 0 );
>      VERIFY( p.compare(s.c_str()) == 0 );
> +    __builtin_printf("Comparing %s as path:%d as string:%d\n", s.c_str(), p.compare(p0), p.compare(s0));
>      VERIFY( p.compare(p0) == p.compare(s0) );
>      VERIFY( p.compare(p0) == p.compare(s0.c_str()) );
>    }
>
>
>
>
> >(cd $target/libstdc++-v3 && make check
> >RUNTESTFLAGS=conformance.exp=*/path/compare/strings/cc) and send me
> >the output from the $target/libstdc++-v3/testsuite/libstdc++.log file?
> >
> >On x86_64 I get:
> >
> >Comparing  as path:-1 as string:-1
> >Comparing / as path:-1 as string:-1
> >Comparing // as path:-1 as string:-1
> >Comparing /. as path:-51 as string:-51
> >Comparing /./ as path:-51 as string:-51
> >Comparing /a as path:-2 as string:-2
> >Comparing /a/ as path:-1 as string:-1
> >Comparing /a// as path:-1 as string:-1
> >Comparing /a/b/c/d as path:1 as string:1
> >Comparing /a//b as path:1 as string:1
> >Comparing a as path:-1 as string:-1
> >Comparing a/b as path:-1 as string:-1
> >Comparing a/b/ as path:-1 as string:-1
> >Comparing a/b/c as path:-1 as string:-1
> >Comparing a/b/c.d as path:-1 as string:-1
> >Comparing a/b/.. as path:-1 as string:-1
> >Comparing a/b/c. as path:-1 as string:-1
> >Comparing a/b/.c as path:-1 as string:-1
> >PASS: 27_io/filesystem/path/compare/strings.cc execution test
> >

Here is what I have on aarch64-none-elf:
Comparing  as path:-1 as string:-1^M
Comparing / as path:-1 as string:-1^M
Comparing // as path:-1 as string:-1^M
Comparing /. as path:-102 as string:-51^M
/libstdc++-v3/testsuite/27_io/filesystem/path/compare/strings.cc:40:
void test01(): Assertion 'p.compare(p0) == p.compare(s0)' failed.^M
^M
*** EXIT code 4242^M
emu: host signal 6^M
FAIL: 27_io/filesystem/path/compare/strings.cc execution test