https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100368
Bug ID: 100368
Summary: Missing guaranteed elision in constexpr evaluation
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: rs2740 at gmail dot com
Target Milestone: ---
struct S {
S() = default;
S(const S&) = delete;
};
struct array {
S s[2];
};
struct PS {
constexpr array operator*() const { return {}; }
};
struct W {
constexpr W(const PS& p) // 1
: t(*p) {}
array t;
};
W w(PS{});
This issues a spurious complaint on trunk and then ICEs:
source>: In constructor 'constexpr W::W(const PS&)':
<source>:17:14: error: use of deleted function 'array::array(array&&)'
17 | : t(*p) {}
| ^
<source>:7:8: note: 'array::array(array&&)' is implicitly deleted because the
default definition would be ill-formed:
7 | struct array {
| ^~~~~
<source>:7:8: error: use of deleted function 'S::S(S&&)'
<source>:4:3: note: declared here
4 | S(S&&) = delete;
| ^
<source>:17:14: internal compiler error: tree check: expected target_expr, have
error_mark in bot_manip, at cp/tree.c:3095
17 | : t(*p) {}
| ^
0x1d002c9 internal_error(char const*, ...)
???:0
0x67b4e3 tree_check_failed(tree_node const*, char const*, int, char const*,
...)
???:0
0x13967e3 walk_tree_1(tree_node**, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*,
tree_node* (*)(tree_node**, int*, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*))
???:0
0x9ad0ae break_out_target_exprs(tree_node*, bool)
???:0
0x72aa0a maybe_save_constexpr_fundef(tree_node*)
???:0
0x7b0711 finish_function(bool)
???:0
0x8e2c4d c_parse_file()
???:0
0xa63232 c_common_parse_file()
???:0
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.
Removing the constexpr on the line marked #1 makes it compile. Both clang and
MSVC accept the original code.
