On Dienstag, 19. Januar 2021 06:54:48 CET Akim Demaille wrote: > Adrian, > > See below for my stab at this issue. Unfortunately it seems to hit > > a problem in GCC10, as the CI features several failures as follows: > > In file included from ../examples/c++/calc++/driver.hh:24, > > > > from ../examples/c++/calc++/driver.cc:20: > > ./examples/c++/calc++/parser.hh: In instantiation of > > 'yy::parser::basic_symbol<Base>::basic_symbol(typename Base::kind_type, > > int&&, yy::parser::location_type&&) [with Base = yy::parser::by_kind; > > typename Base::kind_type = yy::parser::token::token_kind_type; > > yy::parser::location_type = yy::location]': > > ./examples/c++/calc++/parser.hh:742:68: required from here > > ./examples/c++/calc++/parser.hh:583:7: internal compiler error: > > Segmentation fault> > > 583 | basic_symbol (typename Base::kind_type t, int&& v, > > location_type&& l)> > > | ^~~~~~~~~~~~ > > > > Please submit a full bug report, > > with preprocessed source if appropriate. > > See <file:///usr/share/doc/gcc-10/README.Bugs> for instructions. > > I'm not super happy to have to play tricks with compiler macros > to be able to know if I can trust the compiler :( If you see > something wrong in my approach, if you see a nice way to address > this portability issue, please state it. > > The logs of the CI for this commit are here: > > https://travis-ci.org/github/akimd/bison/builds/755133452 > > Cheers! > > commit a7d1aa221efad101d82817345361647fd02a215c > Author: Akim Demaille <akim.demai...@gmail.com> > Date: Mon Jan 18 08:03:44 2021 +0100 > > c++: use YY_NOEXCEPT on the constructor when possible > > Suggested by Adrian <withoutpoi...@gmail.com>. > https://lists.gnu.org/r/help-bison/2021-01/msg00008.html > > * data/skeletons/variant.hh (b4_is_nothrow_move_constructible): New. > * data/skeletons/c++.m4: Use it to qualify the basic_symbol ctor. > > diff --git a/data/skeletons/c++.m4 b/data/skeletons/c++.m4 > index cfd4e6ed7..3496450e2 100644 > --- a/data/skeletons/c++.m4 > +++ b/data/skeletons/c++.m4 > @@ -309,7 +309,9 @@ m4_define([b4_symbol_type_define], > > #if 201103L <= YY_CPLUSPLUS > /// Move constructor. > - basic_symbol (basic_symbol&& that) > + basic_symbol (basic_symbol&& that)]b4_variant_if([ > + YY_NOEXCEPT (]b4_type_foreach([b4_is_nothrow_move_constructible], > [[ + && ]])[)])[ > > : Base (std::move (that)) > > , value (]b4_variant_if([], [std::move
AFAICS you are conditionally inserting the C++ 'noexcept' qualifier to class "basic_symbol"'s constructor (by using C++ type trait std::is_nowthrow_move_constructible()), and at the same time you are still always using std::move() below though. Despite the compiler crash, which shouldn't happen of course, that should be either noexcept & std::move() otherwise no std::move() at all, at least with recent compilers. Not sure what your intention was to leave std::move() unconditionally there, I guess for pre-C++11 compilers? Best regards, Christian Schoenebeck
