On 22.03.2016 15:36, Jonathan Wakely wrote: > On 22/03/16 07:10 +0000, Bernd Edlinger wrote: >> Hi, >> >> I am pinging for this patch, which addresses an admittedly minor >> regression >> for free-standing libstdc++ due to changed c++11 default settings. >> The proposed >> patch does only change the free-standing install rule, and has >> therefore no impact >> on other configurations. >> >> https://gcc.gnu.org/ml/libstdc++/2016-03/msg00004.html > > Sorry for the delay, I'm testing the patch today. > > Looks like the patch doesn't add <bits/boost_concept_check.h> to the > freestanding > headers, which means using -D_GLIBCXX_CONCEPT_CHECKS will give a fatal > error. > > It also means --disable-libstdccxx-hosted --enable-concept-checks > creates an unusable configuration (although it's possible that > --enable-concept-checks is already broken due to the -std=gnu++14 > default). > > I think it's fine for the concept checking to be unsupported for > freestanding installations, but we should degrade gracefully, via > something like: > > --- a/libstdc++-v3/include/bits/concept_check.h > +++ b/libstdc++-v3/include/bits/concept_check.h > @@ -42,7 +42,7 @@ > // Concept-checking code is off by default unless users turn it on via > // configure options or editing c++config.h. > > -#ifndef _GLIBCXX_CONCEPT_CHECKS > +#if !defined(_GLIBCXX_CONCEPT_CHECKS) || !defined(_GLIBCXX_HOSTED) > > #define __glibcxx_function_requires(...) > #define __glibcxx_class_requires(_a,_b) > > > Or in c++config.h doing: > > #ifndef _GLIBCXX_HOSTED > # undef _GLIBCXX_CONCEPT_CHECKS > #endif > > That seems better than just giving an error.
Yes. Maybe changing concept_check.h would be better, because I see 3 different instances of bits/c++config.h: $prefix/arm-eabi/include/c++/6.0.0/arm-eabi/fpu/bits/c++config.h $prefix/arm-eabi/include/c++/6.0.0/arm-eabi/bits/c++config.h $prefix/arm-eabi/include/c++/6.0.0/arm-eabi/thumb/bits/c++config.h while I only see one use of _GLIBCXX_CONCEPT_CHECKS: $prefix/arm-eabi/include/c++/6.0.0/bits/concept_check.h Thanks Bernd.
