https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101914
Bug ID: 101914
Summary: internal compiler error: in tsubst, at cp/pt.c:15553
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: accounts at prantare dot xyz
Target Milestone: ---
The following (preprocessed) code
---
# 0 "main.cpp"
# 0 "<built-in>"
# 0 "<command-line>"
# 1 "/usr/include/stdc-predef.h" 1 3 4
# 0 "<command-line>" 2
# 1 "main.cpp"
template<class>
struct A {
int x;
};
template<class T>
A(T) -> A<T>;
template<auto v>
using B = decltype(A{v});
template<auto v>
auto x = A<B<v>>{};
int main()
{
x<0>;
}
---
yields the following error message:
---
main.cpp: In instantiation of ‘auto x<0>’:
main.cpp:17:5: required from here
main.cpp:13:6: internal compiler error: in tsubst, at cp/pt.c:15553
13 | auto x = A<B<v>>{};
| ^
0x6eef60 tsubst(tree_node*, tree_node*, int, tree_node*)
../../gcc/gcc/cp/pt.c:15553
0xaeb4f4 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
../../gcc/gcc/cp/pt.c:20630
0xb08797 tsubst(tree_node*, tree_node*, int, tree_node*)
../../gcc/gcc/cp/pt.c:16094
0xb0b174 tsubst_template_args(tree_node*, tree_node*, int, tree_node*)
../../gcc/gcc/cp/pt.c:13355
0xb14683 tsubst_aggr_type
../../gcc/gcc/cp/pt.c:13559
0xaeb4f4 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
../../gcc/gcc/cp/pt.c:20630
0xaf62a7 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../gcc/gcc/cp/pt.c:19094
0xafd231 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
../../gcc/gcc/cp/pt.c:18108
0xafd231 tsubst_init
../../gcc/gcc/cp/pt.c:16452
0xafe252 regenerate_decl_from_template
../../gcc/gcc/cp/pt.c:25490
0xafe252 instantiate_body
../../gcc/gcc/cp/pt.c:25813
0xb001ea instantiate_decl(tree_node*, bool, bool)
../../gcc/gcc/cp/pt.c:26171
0x9e07aa maybe_instantiate_decl(tree_node*)
../../gcc/gcc/cp/decl2.c:5495
0x9e1739 maybe_instantiate_decl(tree_node*)
../../gcc/gcc/cp/decl2.c:5698
0x9e1739 mark_used(tree_node*, int)
../../gcc/gcc/cp/decl2.c:5724
0xb3f7b8 finish_id_expression_1
../../gcc/gcc/cp/semantics.c:4132
0xb3fbb7 finish_id_expression(tree_node*, tree_node*, tree_node*, cp_id_kind*,
bool, bool, bool*, bool, bool, bool, bool, char const**, unsigned int)
../../gcc/gcc/cp/semantics.c:4261
0xa9e152 cp_parser_primary_expression
../../gcc/gcc/cp/parser.c:6008
0xaa0aed cp_parser_postfix_expression
../../gcc/gcc/cp/parser.c:7566
0xa8a1aa cp_parser_binary_expression
../../gcc/gcc/cp/parser.c:9896
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.
---
The command that triggers the bug: g++ main.cpp -std=c++20
Version et.c.:
---
$ g++ -v:
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc/configure --disable-multilib
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.0.0 20210813 (experimental) (GCC)
---
The bug appears in 11.1.0 too, on two different machines.
It compiles successfully with clang 14.
