https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98570
Bug ID: 98570
Summary: ICE: canonical types differ for identical types
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: acoplan at gcc dot gnu.org
Target Milestone: ---
GCC ICEs on the following (on at least aarch64 and x86). The testcase was
reduced from polymake and is accepted by clang.
template <int a> struct b { static constexpr int c = a; };
template <int> struct h { typedef int d; };
template <bool e, typename> using f = typename h<e>::d;
namespace g {
template <typename...> using i = b<false>;
using j = long;
}
using g::i;
using g::j;
template <typename> using k = i<>;
template <typename... l> f<!i<l...>::c, j> m();
template <typename... n> f<!i<k<n>...>::c, j> m();
On AArch64, I can reproduce the ICE back to GCC 6. To reproduce:
$ aarch64-elf-gcc -c testcase.ii
testcase.ii:12:49: internal compiler error: canonical types differ for
identical types 'h<(! g::i<k<n>...>::c)>' and 'h<(! g::i<l ...>::c)>'
12 | template <typename... n> f<!i<k<n>...>::c, j> m();
| ^
0x9f85e5 comptypes(tree_node*, tree_node*, int)
/home/alecop01/toolchain/src/gcc/gcc/cp/typeck.c:1543
0x9f9900 same_type_ignoring_top_level_qualifiers_p(tree_node*, tree_node*)
/home/alecop01/toolchain/src/gcc/gcc/cp/typeck.c:1579
0x9f7827 structural_comptypes
/home/alecop01/toolchain/src/gcc/gcc/cp/typeck.c:1423
0x9f8570 comptypes(tree_node*, tree_node*, int)
/home/alecop01/toolchain/src/gcc/gcc/cp/typeck.c:1532
0x7b9309 decls_match(tree_node*, tree_node*, bool)
/home/alecop01/toolchain/src/gcc/gcc/cp/decl.c:1026
0x7b983c decls_match(tree_node*, tree_node*, bool)
/home/alecop01/toolchain/src/gcc/gcc/cp/decl.c:1080
0x7bacf8 duplicate_decls(tree_node*, tree_node*, bool, bool)
/home/alecop01/toolchain/src/gcc/gcc/cp/decl.c:1459
0x8aed4d do_pushdecl
/home/alecop01/toolchain/src/gcc/gcc/cp/name-lookup.c:3734
0x8b13cc do_pushdecl_with_scope
/home/alecop01/toolchain/src/gcc/gcc/cp/name-lookup.c:4881
0x8b1533 pushdecl_namespace_level(tree_node*, bool)
/home/alecop01/toolchain/src/gcc/gcc/cp/name-lookup.c:6245
0x97701e push_template_decl(tree_node*, bool)
/home/alecop01/toolchain/src/gcc/gcc/cp/pt.c:6049
0x7d1839 start_decl(cp_declarator const*, cp_decl_specifier_seq*, int,
tree_node*, tree_node*, tree_node**)
/home/alecop01/toolchain/src/gcc/gcc/cp/decl.c:5531
0x8fc85e cp_parser_init_declarator
/home/alecop01/toolchain/src/gcc/gcc/cp/parser.c:21659
0x8ff1fb cp_parser_single_declaration
/home/alecop01/toolchain/src/gcc/gcc/cp/parser.c:30427
0x8ff2f8 cp_parser_template_declaration_after_parameters
/home/alecop01/toolchain/src/gcc/gcc/cp/parser.c:29999
0x8ffc2d cp_parser_explicit_template_declaration
/home/alecop01/toolchain/src/gcc/gcc/cp/parser.c:30265
0x8ffc2d cp_parser_template_declaration_after_export
/home/alecop01/toolchain/src/gcc/gcc/cp/parser.c:30284
0x90026a cp_parser_template_declaration
/home/alecop01/toolchain/src/gcc/gcc/cp/parser.c:16533
0x909dcd cp_parser_declaration
/home/alecop01/toolchain/src/gcc/gcc/cp/parser.c:14009
0x908f3b cp_parser_toplevel_declaration
/home/alecop01/toolchain/src/gcc/gcc/cp/parser.c:14107
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.
