Re: trunk -D_GLIBCXX_DEBUG #include <regex> fails

[Jonathan Wakely <jwakely@redhat.com>]

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.