https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98346
Bug ID: 98346 Summary: ICE with a combination of concepts, decltype and type aliases Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: drozdov_xf2g3gb3 at mail dot ru Target Milestone: --- The following code(https://godbolt.org/z/asPv6s): template <class, class...> concept always_satisfied = true; using arg_alias = int; template <always_satisfied F> using result_of = decltype(F{}(arg_alias{})); template <class F> always_satisfied<result_of<F>> auto foo(F) {} void bar() { foo([](auto){}); } When compiled with -v -std=c++20 produces: Using built-in specs. COLLECT_GCC=/opt/compiler-explorer/gcc-snapshot/bin/g++ COLLECT_LTO_WRAPPER=/opt/compiler-explorer/gcc-trunk-20201217/bin/../libexec/gcc/x86_64-linux-gnu/11.0.0/lto-wrapper Target: x86_64-linux-gnu Configured with: ../gcc-trunk-20201217/configure --prefix=/opt/compiler-explorer/gcc-build/staging --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --disable-bootstrap --enable-multiarch --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --enable-clocale=gnu --enable-languages=c,c++,fortran,ada,d --enable-ld=yes --enable-gold=yes --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-linker-build-id --enable-lto --enable-plugins --enable-threads=posix --with-pkgversion=Compiler-Explorer-Build Thread model: posix Supported LTO compression algorithms: zlib gcc version 11.0.0 20201216 (experimental) (Compiler-Explorer-Build) COLLECT_GCC_OPTIONS='-fdiagnostics-color=always' '-g' '-o' './output.s' '-L.' '-v' '-std=c++20' '-shared-libgcc' '-mtune=generic' '-march=x86-64' '-dumpdir' './output.s-' /opt/compiler-explorer/gcc-trunk-20201217/bin/../libexec/gcc/x86_64-linux-gnu/11.0.0/cc1plus -quiet -v -imultiarch x86_64-linux-gnu -iprefix /opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/x86_64-linux-gnu/11.0.0/ -D_GNU_SOURCE <source> -quiet -dumpdir ./output.s- -dumpbase example.cpp -dumpbase-ext .cpp -mtune=generic -march=x86-64 -g -std=c++20 -version -fdiagnostics-color=always -o /tmp/ccwWsVpH.s GNU C++20 (Compiler-Explorer-Build) version 11.0.0 20201216 (experimental) (x86_64-linux-gnu) compiled by GNU C version 7.5.0, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.18-GMP GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096 ignoring nonexistent directory "/opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/x86_64-linux-gnu/11.0.0/../../../../x86_64-linux-gnu/include" ignoring duplicate directory "/opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.0.0/../../../../include/c++/11.0.0" ignoring duplicate directory "/opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.0.0/../../../../include/c++/11.0.0/x86_64-linux-gnu" ignoring duplicate directory "/opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.0.0/../../../../include/c++/11.0.0/backward" ignoring duplicate directory "/opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.0.0/include" ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu" ignoring duplicate directory "/opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.0.0/include-fixed" ignoring nonexistent directory "/opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.0.0/../../../../x86_64-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/x86_64-linux-gnu/11.0.0/../../../../include/c++/11.0.0 /opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/x86_64-linux-gnu/11.0.0/../../../../include/c++/11.0.0/x86_64-linux-gnu /opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/x86_64-linux-gnu/11.0.0/../../../../include/c++/11.0.0/backward /opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/x86_64-linux-gnu/11.0.0/include /opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/x86_64-linux-gnu/11.0.0/include-fixed /usr/local/include /opt/compiler-explorer/gcc-trunk-20201217/bin/../lib/gcc/../../include /usr/include/x86_64-linux-gnu /usr/include End of search list. GNU C++20 (Compiler-Explorer-Build) version 11.0.0 20201216 (experimental) (x86_64-linux-gnu) compiled by GNU C version 7.5.0, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.18-GMP GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096 Compiler executable checksum: b4bad02868d3360f899970e9993fe4c2 <source>: In instantiation of 'auto [requires ::always_satisfied<<placeholder>, decltype({}({}))>] foo(F) [with F = bar()::<lambda(auto:1)>]': <source>:12:32: required from here <source>:10:49: internal compiler error: Segmentation fault 10 | always_satisfied<result_of<F>> auto foo(F) {} | ^ 0x1c97449 internal_error(char const*, ...) ???:0 0x9772c3 finish_decltype_type(tree_node*, bool, int) ???:0 0x9ac5d8 strip_typedefs(tree_node*, bool*, unsigned int) ???:0 0x8ddf7e canonicalize_type_argument(tree_node*, int) ???:0 0x729bfa build_concept_check(tree_node*, tree_node*, tree_node*, int) ???:0 0x8f6c60 do_auto_deduction(tree_node*, tree_node*, tree_node*, int, auto_deduction_context, tree_node*, int) ???:0 0x79f2e7 finish_function(bool) ???:0 0x90959f instantiate_decl(tree_node*, bool, bool) ???:0 0x7b6a3e maybe_instantiate_decl(tree_node*) ???:0 0x7b8100 mark_used(tree_node*, int) ???:0 0x6d1657 build_new_function_call(tree_node*, vec<tree_node*, va_gc, vl_embed>**, int) ???:0 0x96cf4c finish_call_expr(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool, bool, int) ???:0 0x8cf015 c_parse_file() ???:0 0xa4ae82 c_common_parse_file() ???:0 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions.