On 05/12/19 17:12 +0100, Christophe Lyon wrote:
On Thu, 5 Dec 2019 at 12:43, Jonathan Wakely <jwak...@redhat.com> wrote:
On 05/12/19 09:00 +0100, Christophe Lyon wrote:
>On Tue, 3 Dec 2019 at 10:16, Jonathan Wakely <jwak...@redhat.com> wrote:
>>
>> On 03/12/19 09:11 +0100, Christophe Lyon wrote:
>> >On Mon, 16 Sep 2019 at 04:34, Tom Honermann <t...@honermann.net> wrote:
>> >>
>> >> A revised patch is attached that modifies the tests for deleted ostream
>> >> inserters to require C++2a. This is required by the revision of patch
>> >> 2/4 that adds proper preprocessor conditionals to the definitions.
>> >>
>> >> Tom.
>> >>
>> >> On 9/15/19 3:40 PM, Tom Honermann wrote:
>> >> > This patch adds new tests to validate new deleted overloads of wchar_t,
>> >> > char8_t, char16_t, and char32_t for ordinary and wide formatted
>> >> > character and string ostream inserters.
>> >> >
>> >> > Additionally, new tests are added to validate invocations of u8path with
>> >> > sequences of char8_t for both the C++17 and filesystem TS
implementations.
>> >> >
>> >> > libstdc++-v3/ChangeLog:
>> >> >
>> >> > 2019-09-15 Tom Honermann <t...@honermann.net>
>> >> >
>> >> > *
>> >> >
libstdc++-v3/testsuite/27_io/basic_ostream/inserters_character/char/deleted.cc:
>> >> >
>> >> > New test to validate deleted overloads of character and string
>> >> > inserters for narrow ostreams.
>> >> > *
>> >> >
libstdc++-v3/testsuite/27_io/basic_ostream/inserters_character/wchar_t/deleted.cc:
>> >> >
>> >> > New test to validate deleted overloads of character and string
>> >> > inserters for wide ostreams.
>> >> > *
>> >> > libstdc++-v3/testsuite/27_io/filesystem/path/factory/u8path-char8_t.cc:
>> >> > New test to validate u8path invocations with sequences of
>> >> > char8_t.
>> >> > *
>> >> >
libstdc++-v3/testsuite/experimental/filesystem/path/factory/u8path-char8_t.cc
>> >> >
>> >> > New test to validate u8path invocations with sequences of
>> >> > char8_t.
>> >> >
>> >
>> >Hi,
>> >
>> >I've noticed that the new test
>> >27_io/filesystem/path/factory/u8path-char8_t.cc
>> >fails to compile on arm-none-eabi with default cpu/fpu, because:
>> >/tools/arm-none-eabi/bin/ld:
>>
>/obj-arm-none-eabi/gcc3/arm-none-eabi/libstdc++-v3/src/.libs/libstdc++.a(string-inst.o):
>> >in function `_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEaSEOS4_':
>>
>string-inst.cc:(.text._ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEaSEOS4_[_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEaSEOS4_]+0xf4):
>> >undefined reference to `_ZSt15__alloc_on_moveISaIcEEvRT_S2_'
>> >[etc...]
>>
>> That function is defined inline and so should be instantiated in any
>> TU that needs it, and so should not give linker errors. There was a
>> similar bug reported the other day that turned out to be pilot error:
>> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92733
>>
>Hi,
>Sorry for the delay, it took me a while to reproduce the problem manually.
>I think I see this because I build that particular configuration with
>CXXFLAGS_FOR_TARGET=-fno-threadsafe-statics
>
>Does that sound plausible?
Not really ... I still don't know why that function template would
ever be undefined.
Hmmm that's because doing CXXFLAGS_FOR_TARGET means that the generated
Makefile contains:
CXXFLAGS = -fno-threadsafe-statics
while if I don't define CXXFLAGS_FOR_TARGET, it contains
CXXFLAGS = -g -O2 -D_GNU_SOURCE
Re-compiling string-inst with -O2 removes the undefined reference
Sigh... looks like I fixed something similar 7 years ago :-(
https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=189046
So... the current configure.ac code makes sure -O2 and -g are present
in CXXFLAGS_FOR_TARGET only if it's derived from CXXFLAGS, which
happens only when CXXFLAGS_FOR_TARGET is NOT overridden, and not
cross-compiling...
We have:
case " $CXXFLAGS " in
*" -O2 "*) ;;
*) CXXFLAGS_FOR_TARGET="-O2 $CXXFLAGS_FOR_TARGET" ;;
esac
Why isn't it case "$CXXFLAGS_FOR_TARGET" instead? And that whole
case/esac should be after the 'fi'.
Or is it that way on purpose?
So it seems the fix for the problem I saw is for me to use
CXXFLAGS_FOR_TARGET="-O2 -g -fno-threadsafe-statics"
This is https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92927 and thanks
to the bisected revision number in the PR I see what the problem is.
