https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93664
Bug ID: 93664 Summary: ICE: Segmentation fault on invalid concept code gcc/gcc/cp/constraint.cc:2537 Product: gcc Version: 10.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: gcc-bugs at marehr dot dialup.fu-berlin.de Target Milestone: --- Hi gcc-team, this (invalid!) code ICEs: ```c++ #include <iterator> #include <utility> template <typename T> concept bool semiregular = requires(T t) { {(t != t)}; }; template <typename T> concept bool view_ = semiregular<T>; template <bool B> concept bool is_true = B; // this part is invalid, commenting in =, or // ommiting bool resolves the ICE template <typename T> concept bool pair_like_convertible_from_ /*=*/ (is_true<true>); template <typename I> struct subrange { template <typename PairLike> requires pair_like_convertible_from_<PairLike> operator PairLike(); }; int main() { subrange<std::istreambuf_iterator<char>> sub; view_<decltype(sub)>; } ``` https://godbolt.org/z/c__ob5 When replacing all `concept bool` with `concept` the ICE vanishes. ``` > g++-git --std=c++2a ice.cpp: In instantiation of ‘subrange<I>::operator PairLike() [with PairLike = const std::error_condition; I = std::istreambuf_iterator<char, std::char_traits<char> >]’: ice.cpp:6:7: required from here ice.cpp:6:7: internal compiler error: Segmentation fault 6 | {(t != t)}; | ~~~^~~~~ 0xc8026f crash_signal /home/marehr/Packages/gcc-git/src/gcc/gcc/toplev.c:328 0x69819d force_rvalue(tree_node*, int) /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/cvt.c:564 0x6834c2 satisfy_constraint_r /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/constraint.cc:2537 0x683bf8 satisfy_constraint /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/constraint.cc:2599 0x6845c4 satisfy_declaration_constraints /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/constraint.cc:2617 0x6850e8 constraint_satisfaction_value /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/constraint.cc:2733 0x6850e8 constraints_satisfied_p(tree_node*) /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/constraint.cc:2754 0x6511f2 add_function_candidate /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:2281 0x6537fc add_template_candidate_real /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:3440 0x653d86 add_template_candidate /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:3481 0x653d86 add_candidates /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:5829 0x64f0b5 add_candidates /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:5744 0x64f0b5 build_user_type_conversion_1 /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:4079 0x64fb43 reference_binding /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:1843 0x650121 implicit_conversion /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:1992 0x650e79 add_function_candidate /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:2389 0x653dc4 add_candidates /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:5842 0x654357 add_candidates /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:5744 0x654357 add_operator_candidates /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:5933 0x659344 build_new_op_1 /home/marehr/Packages/gcc-git/src/gcc/gcc/cp/call.c:6156 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://bugs.archlinux.org/> for instructions. ``` ``` > g++-git -v Using built-in specs. COLLECT_GCC=g++-git COLLECT_LTO_WRAPPER=/opt/gcc/gcc-git/bin/../lib/gcc/x86_64-pc-linux-gnu/10.0.1/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /home/marehr/Packages/gcc-git/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++ --enable-shared --enable-threads=posix --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --enable-multilib --disable-werror --enable-checking=release --enable-default-pie --enable-default-ssp --enable-cet=auto --disable-boostrap Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 10.0.1 20200206 (experimental) (GCC) ```