https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105756
Bug ID: 105756 Summary: ICE in cxx_eval_constant_expression at cp/constexpr.cc:7586: unexpected expression ‘ElemSize’ of kind template_parm_index Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: slyfox at gcc dot gnu.org Target Milestone: --- Originally reported by tt_1 at https://bugs.gentoo.org/847601 on 0ad-0.0.25b project. I see two similar ICEs in bugzilla but not sure they are the happening in same area. Here is the minimized example that seems to be buildable by clang: // $ cat RegExp.cpp.cpp template <int ElemSize> decltype(0 % ElemSize == 0) a; $ g++ -o RegExp.o -c -O2 RegExp.cpp.cpp RegExp.cpp.cpp:1:47: internal compiler error: unexpected expression ‘ElemSize’ of kind template_parm_index 1 | template <int ElemSize> decltype(0 % ElemSize == 0) a; | ~~~~~~~~~~~~~^~~~ 0xa39bb3 cxx_eval_constant_expression ../../gcc-13-20220522/gcc/cp/constexpr.cc:7586 0xa39eab cxx_eval_outermost_constant_expr ../../gcc-13-20220522/gcc/cp/constexpr.cc:7823 0xa3cc89 potential_constant_expression_1 ../../gcc-13-20220522/gcc/cp/constexpr.cc:9272 0xa3d8a9 potential_constant_expression_1(tree_node*, bool, bool, bool, int) ../../gcc-13-20220522/gcc/cp/constexpr.cc:9548 0xa3d8a9 is_constant_expression(tree_node*) ../../gcc-13-20220522/gcc/cp/constexpr.cc:9605 0xa3d8a9 is_nondependent_constant_expression(tree_node*) ../../gcc-13-20220522/gcc/cp/constexpr.cc:9642 0xa3e83f maybe_constant_value(tree_node*, tree_node*, bool) ../../gcc-13-20220522/gcc/cp/constexpr.cc:8069 0xa6dea4 cp_fully_fold(tree_node*) ../../gcc-13-20220522/gcc/cp/cp-gimplify.cc:2353 0xa6dea4 cp_fully_fold(tree_node*) ../../gcc-13-20220522/gcc/cp/cp-gimplify.cc:2345 0xc6a059 cp_build_binary_op(op_location_t const&, tree_code, tree_node*, tree_node*, int) ../../gcc-13-20220522/gcc/cp/typeck.cc:6260 0xa09a50 build_new_op(op_location_t const&, tree_code, int, tree_node*, tree_node*, tree_node*, tree_node*, tree_node**, int) ../../gcc-13-20220522/gcc/cp/call.cc:6930 0xc5d87e build_x_binary_op(op_location_t const&, tree_code, tree_node*, tree_code, tree_node*, tree_code, tree_node*, tree_node**, int) ../../gcc-13-20220522/gcc/cp/typeck.cc:4563 0xbcfba1 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool, bool) ../../gcc-13-20220522/gcc/cp/pt.cc:20347 0xbd4c27 instantiate_non_dependent_expr_internal(tree_node*, int) ../../gcc-13-20220522/gcc/cp/pt.cc:6366 0xbd4c27 instantiate_non_dependent_expr_sfinae(tree_node*, int) ../../gcc-13-20220522/gcc/cp/pt.cc:6387 0xc2d789 finish_decltype_type(tree_node*, bool, int) ../../gcc-13-20220522/gcc/cp/semantics.cc:11297 0xb837d1 cp_parser_decltype ../../gcc-13-20220522/gcc/cp/parser.cc:16578 0xb9cd49 cp_parser_simple_type_specifier ../../gcc-13-20220522/gcc/cp/parser.cc:19693 0xb78a07 cp_parser_type_specifier ../../gcc-13-20220522/gcc/cp/parser.cc:19470 0xb79a21 cp_parser_decl_specifier_seq ../../gcc-13-20220522/gcc/cp/parser.cc:15940 Please submit a full bug report, with preprocessed source (by using -freport-bug). Please include the complete backtrace with any bug report. See <https://gcc.gnu.org/bugs/> for instructions. $ g++ -v Using built-in specs. COLLECT_GCC=/<<NIX>>/gcc-debug-13.0.0/bin/g++ COLLECT_LTO_WRAPPER=/<<NIX>>/gcc-debug-13.0.0/libexec/gcc/x86_64-unknown-linux-gnu/13.0.0/lto-wrapper Target: x86_64-unknown-linux-gnu Configured with: Thread model: posix Supported LTO compression algorithms: zlib gcc version 13.0.0 20220522 (experimental) (GCC)