https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103912
Bug ID: 103912 Summary: ICE in a consteval function in cp_gimplify_expr, at cp/cp-gimplify.c:557 Product: gcc Version: 11.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: 0xd34df00d at gmail dot com Target Milestone: --- This program: #include <string_view> namespace { constexpr uint64_t CalcHash (std::string_view name) { return 0; } template<typename T> struct Command { const uint64_t Hash_; const T Cmd_; consteval Command (std::string_view name, T cmd) : Hash_ { CalcHash (name) } , Cmd_ { cmd } { } }; template<typename T> consteval auto MakeHash (auto&&... commands) { const std::initializer_list<Command<T>> commandsList { commands... }; for (auto i = commandsList.begin (); i != std::prev (commandsList.end ()); ++i) for (auto j = std::next (i); j != commandsList.end (); ++j) if (i->Hash_ == j->Hash_) throw "duplicate hashes"; return [=] (std::string_view str) { const auto strHash = CalcHash (str); T result {}; ((commands.Hash_ == strHash && (result = commands.Cmd_)) || ...); return result; }; } } struct Foo { int foo1(int x) { return x * 1; } }; int bar(std::string_view arg) { constexpr auto hash = MakeHash<int (Foo::*) (int)> (Command { "foo1", &Foo::foo1 }); Foo f {}; auto res = hash(arg); return (f.*res)(42); } compiled with -std=c++20 (as in g++ -std=c++20 foo.cpp -o foo.o) results in foo.cpp: In function 'consteval auto {anonymous}::MakeHash(auto:11&& ...) [with T = int (Foo::*)(int); auto:11 = {{anonymous}::Command<int (Foo::*)(int)>}]': foo.cpp:27:17: internal compiler error: in cp_gimplify_expr, at cp/cp-gimplify.c:557 27 | for (auto i = commandsList.begin (); i != std::prev (commandsList.end ()); ++i) | ^~~ 0x164bc1d internal_error(char const*, ...) ???:0 0x604ee1 fancy_abort(char const*, int, char const*) ???:0 0xa7662b gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ???:0 0xa77265 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ???:0 0xa7734c gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ???:0 0xa77265 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ???:0 0xa7734c gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ???:0 0xa85bd4 gimplify_body(tree_node*, bool) ???:0 0xa8611e gimplify_function_tree(tree_node*) ???:0 0x8fd5ab cgraph_node::analyze() ???:0 0x903af3 symbol_table::finalize_compilation_unit() ???:0 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <https://bugs.gentoo.org/> for instructions. This reproduces both with gcc 11.1.0 and 11.2.1: Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/11.2.1/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /var/tmp/portage/sys-devel/gcc-11.2.1_p20211127/work/gcc-11-20211127/configure --host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/11.2.1 --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.1/include --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.2.1 --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.2.1/man --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.2.1/info --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/11.2.1/include/g++-v11 --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/11.2.1/python --enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --disable-libunwind-exceptions --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 11.2.1_p20211127 p3' --disable-esp --enable-libstdcxx-time --with-build-config=bootstrap-lto --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --enable-multilib --with-multilib-list=m32,m64 --disable-fixed-point --enable-targets=all --enable-libgomp --disable-libssp --disable-libada --disable-cet --disable-systemtap --disable-valgrind-annotations --disable-vtable-verify --disable-libvtv --without-zstd --enable-lto --with-isl --disable-isl-version-check --disable-default-pie --enable-default-ssp Thread model: posix Supported LTO compression algorithms: zlib gcc version 11.2.1 20211127 (Gentoo 11.2.1_p20211127 p3)