Re: trunk -D_GLIBCXX_DEBUG #include <regex> fails

[Jonathan Wakely <jwakely@redhat.com>]

On Mon, 9 Aug 2021 at 15:42, Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On Mon, 9 Aug 2021 at 15:27, Jonathan Wakely wrote:
> >
> > On Mon, 9 Aug 2021 at 13:05, François Dumont via Libstdc++
> > <libstdc++@gcc.gnu.org> wrote:
> > >
> > > On 09/08/21 12:05 pm, Jonathan Wakely via Libstdc++ wrote:
> > > > On Mon, 9 Aug 2021 at 10:51, Stephan Bergmann via Libstdc++
> > > > <libstdc++@gcc.gnu.org> wrote:
> > > >> Not sure why I started to experience this now with a recent
> > > >> GCC/libstdc++ trunk build:
> > > >>
> > > >>> $ cat test.cc
> > > >>> #include <regex>
> > > >>> $ gcc/trunk/inst/bin/g++ -D_GLIBCXX_DEBUG -fsyntax-only test.cc
> > > >>> In file included from /home/sbergman/gcc/trunk/inst/include/c++/12.0.0/bits/regex_automaton.h:401,
> > > >>>                   from /home/sbergman/gcc/trunk/inst/include/c++/12.0.0/regex:60,
> > > >>>                   from test.cc:1:
> > > >>> /home/sbergman/gcc/trunk/inst/include/c++/12.0.0/bits/regex_automaton.tcc: In member function ‘std::__detail::_StateSeq<_TraitsT> std::__detail::_StateSeq<_TraitsT>::_M_clone()’:
> > > >>> /home/sbergman/gcc/trunk/inst/include/c++/12.0.0/bits/regex_automaton.tcc:197:12: error: ‘map’ is not a member of ‘std’
> > > >>>    197 |       std::map<_StateIdT, _StateIdT> __m;
> > > >>>        |            ^~~
> > > >> [...]
> > > >>> In file included from /home/sbergman/gcc/trunk/inst/include/c++/12.0.0/regex:62,
> > > >>>                   from test.cc:1:
> > > >>> /home/sbergman/gcc/trunk/inst/include/c++/12.0.0/bits/regex_compiler.h: At global scope:
> > > >>> /home/sbergman/gcc/trunk/inst/include/c++/12.0.0/bits/regex_compiler.h:541:12: error: ‘vector’ in namespace ‘std’ does not name a template type
> > > >>>    541 |       std::vector<_CharT>                       _M_char_set;
> > > >>>        |            ^~~~~~
> > > >> [...]
> > > >>
> > > >> where neither the use of std::map in bits/regex_automaton.tcc nor the
> > > >> use of std::vector in bits/regex_compiler.h are in _GLIBCXX_DEBUG-only
> > > >> code (but compiling without -D_GLIBCXX_DEBUG succeeded).
> > > > With that flag the container implementations are defined in namespace
> > > > __gnu_cxx1998, and std::map is supposed to refer to __gnu_debug::map.
> > > > But the debug map is declared in a header which isn't included by
> > > > <regex> since I replaced <map> with <bits/stl_map.h>.
> > > >
> > > >
> > > >
> > > >> Anyway, what would apparently fix it for me is
> > > >>
> > > >>> diff --git a/libstdc++-v3/include/std/regex b/libstdc++-v3/include/std/regex
> > > >>> index 04fb8b2d971..29fd2956fd0 100644
> > > >>> --- a/libstdc++-v3/include/std/regex
> > > >>> +++ b/libstdc++-v3/include/std/regex
> > > >>> @@ -42,6 +42,11 @@
> > > >>>   #include <stdexcept>
> > > >>>   #include <string>
> > > >>>
> > > >>> +#if defined _GLIBCXX_DEBUG
> > > >>> +#include <map>
> > > >>> +#include <vector>
> > > >>> +#endif
> > > >>> +
> > > > I think we can do this instead:
> > > >
> > > > --- a/libstdc++-v3/include/std/regex
> > > > +++ b/libstdc++-v3/include/std/regex
> > > > @@ -63,6 +63,11 @@
> > > > #include <bits/regex.h>
> > > > #include <bits/regex_executor.h>
> > > >
> > > > +#ifdef _GLIBCXX_DEBUG
> > > > +# include <debug/map>
> > > > +# include <debug/vector>
> > > > +#endif
> > > > +
> > > > #if __cplusplus >= 201703L && _GLIBCXX_USE_CXX11_ABI
> > > > namespace std _GLIBCXX_VISIBILITY(default)
> > > > {
> > > >
> > > >
> > > > I'll test it, thanks for the report.
> > > >
> > > We are confident about the usage of those containers in the regex
> > > implementation, aren't we ?
> > >
> > > You can normally avoid the includes if you use for example
> > > _GLIBCXX_STD_C::map rather than std::map.
> >
> > Yes, I have a patch to do that.
>
> This is what I'm testing.

Pushed to trunk now.