https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119998
Bug ID: 119998
Summary: ICE (segfault) on missing constraint in redeclaration.
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: luc.grosheintz at gmail dot com
Target Milestone: ---
Created attachment 61235
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=61235&action=edit
Preprocessed sources and compilation command.
The reproducer has also been setup on Godbolt:
https://godbolt.org/z/o8Y6rGWfq
The following invalid code causes a segfault in GCC trunk (e.g. commit
`1c0cbc1b300e08df5ebfce00a7195890d78f2064`):
```
struct A {
template <typename T>
struct B;
};
template <typename T>
requires true
struct A::B
{
template<typename U>
B(U u);
};
template<typename T>
template<typename U>
A::B<T>::B(U u) {}
```
(the requires clause differs in the redeclaration.)
The error message is:
```
Segmentation fault
16 | A::B<T>::B(U u) {}
| ^
0x29720df internal_error(char const*, ...)
../../gcc-bug/gcc/diagnostic-global-context.cc:517
0x145866f crash_signal
../../gcc-bug/gcc/toplev.cc:321
0xbd4fed cp_printer
../../gcc-bug/gcc/cp/error.cc:4689
0x2995638 format_phase_2
../../gcc-bug/gcc/pretty-print.cc:2157
0x2995638 pretty_printer::format(text_info&)
../../gcc-bug/gcc/pretty-print.cc:1710
0x295c238 pp_format(pretty_printer*, text_info*)
../../gcc-bug/gcc/pretty-print.h:594
0x295c238 diagnostic_context::report_diagnostic(diagnostic_info*)
../../gcc-bug/gcc/diagnostic.cc:1504
0x295c665 diagnostic_context::diagnostic_impl(rich_location*,
diagnostic_metadata const*, diagnostic_option_id, char const*, __va_list_tag
(*) [1], diagnostic_t)
../../gcc-bug/gcc/diagnostic.cc:1640
0x29718af error(char const*, ...)
../../gcc-bug/gcc/diagnostic-global-context.cc:397
0xd3c9cd push_template_decl(tree_node*, bool)
../../gcc-bug/gcc/cp/pt.cc:6250
0xb88aab start_preparsed_function(tree_node*, tree_node*, int)
../../gcc-bug/gcc/cp/decl.cc:18500
0xb9f946 start_function(cp_decl_specifier_seq*, cp_declarator const*,
tree_node*)
../../gcc-bug/gcc/cp/decl.cc:18837
0xccbfd7 cp_parser_function_definition_from_specifiers_and_declarator
../../gcc-bug/gcc/cp/parser.cc:33569
0xccbfd7 cp_parser_init_declarator
../../gcc-bug/gcc/cp/parser.cc:24051
0xcd40e3 cp_parser_single_declaration
../../gcc-bug/gcc/cp/parser.cc:34112
0xcd433f cp_parser_template_declaration_after_parameters
../../gcc-bug/gcc/cp/parser.cc:33766
0xcd433f cp_parser_explicit_template_declaration
../../gcc-bug/gcc/cp/parser.cc:33940
0xcd4767 cp_parser_template_declaration_after_export
../../gcc-bug/gcc/cp/parser.cc:33959
0xcd4767 cp_parser_template_declaration_after_parameters
../../gcc-bug/gcc/cp/parser.cc:33754
0xcd4767 cp_parser_explicit_template_declaration
../../gcc-bug/gcc/cp/parser.cc:33940
Please submit a full bug report, with preprocessed source.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Preprocessed source stored into /tmp/ccLr1ffQ.out file, please attach this to
your bugreport.
```
The bug looks similar to PR118060 but the reproducer in that bug report doesn't
fail anymore on GCC trunk.
On Godbolt GCC 15.1 prints the following error message:
```
<source>:16: confused by earlier errors, bailing out
```
