[2/2] c++: note other candidates when diagnosing deletedness
Checks
Commit Message
With the previous improvements in place, we can easily extend our
deletedness diagnostic to note the other candidates:
deleted16.C: In function ‘int main()’:
deleted16.C:10:4: error: use of deleted function ‘void f(int)’
10 | f(0);
| ~^~~
deleted16.C:5:6: note: declared here
5 | void f(int) = delete;
| ^
deleted16.C:5:6: note: candidate: ‘void f(int)’ (deleted)
deleted16.C:6:6: note: candidate: ‘void f(...)’
6 | void f(...);
| ^
deleted16.C:7:6: note: candidate: ‘void f(int, int)’
7 | void f(int, int);
| ^
deleted16.C:7:6: note: candidate expects 2 arguments, 1 provided
These notes are disabled when a deleted special member function is
selected primarily because it introduces a lot of new "cannot bind
reference" errors in the testsuite when noting non-viable candidates,
e.g. in cpp0x/initlist-opt1.C we would need to expect an error at
A(A&&).
gcc/cp/ChangeLog:
* call.cc (build_over_call): Call print_z_candidates when
diagnosing deletedness.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/deleted16.C: New test.
---
gcc/cp/call.cc | 10 +++++++++-
gcc/testsuite/g++.dg/cpp0x/deleted16.C | 11 +++++++++++
2 files changed, 20 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp0x/deleted16.C
@@ -9873,7 +9873,15 @@ build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
if (DECL_DELETED_FN (fn))
{
if (complain & tf_error)
- mark_used (fn);
+ {
+ mark_used (fn);
+ /* Note the other candidates we considered unless we selected a
+ special member function since the mismatch reasons for other
+ candidates are usually uninteresting, e.g. rvalue vs lvalue
+ reference binding . */
+ if (cand->next && !special_memfn_p (fn))
+ print_z_candidates (input_location, cand, /*only_viable_p=*/false);
+ }
return error_mark_node;
}
new file mode 100644
@@ -0,0 +1,11 @@
+// Verify we note other candidates when a deleted function is
+// selected by overload resolution.
+// { dg-do compile { target c++11 } }
+
+void f(int) = delete; // { dg-message "declared here|candidate" }
+void f(...); // { dg-message "candidate" }
+void f(int, int); // { dg-message "candidate" }
+
+int main() {
+ f(0); // { dg-error "deleted" }
+}