On Fri, 27 Oct 2023, Jason Merrill wrote:
On 10/27/23 15:55, Patrick Palka wrote:
With the previous two patches in place, we can now extend our
deletedness diagnostic to note the other considered candidates, e.g.:
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 controlled by a new command line flag -fnote-all-cands,
which also controls whether we note ignored candidates more generally.
gcc/ChangeLog:
* doc/invoke.texi (C++ Dialect Options): Document -fnote-all-cands.
gcc/c-family/ChangeLog:
* c.opt: Add -fnote-all-cands.
gcc/cp/ChangeLog:
* call.cc (print_z_candidates): Only print ignored candidates
when -fnote-all-cands is set.
(build_over_call): When diagnosing deletedness, call
print_z_candidates if -fnote-all-cands is set.
My suggestion was also to suggest using the flag in cases where it would make
a difference, e.g.
note: some candidates omitted, use '-fnote-all-cands' to display them
Ah thanks, fixed. That'll help a lot with discoverability of the flag.
Maybe "-fdiagnostics-all-candidates"?
Nice, that's a better name indeed :)
How does the following look? Full bootstrap/regtest in progress.
Here's the output of e.g. deleted16a.C. I think I'd prefer to not print
the source line when emitting the suggestion, but I don't know how to do
that properly (aside from e.g. emitting the note at UNKNOWN_LOCATION).
In file included from gcc/testsuite/g++.dg/cpp0x/deleted16a.C:4:
gcc/testsuite/g++.dg/cpp0x/deleted16.C: In function ‘int main()’:
gcc/testsuite/g++.dg/cpp0x/deleted16.C:21:4: error: use of deleted function
‘void f(int)’
21 | f(0); // { dg-error "deleted" }
| ~^~~
gcc/testsuite/g++.dg/cpp0x/deleted16.C:6:6: note: declared here
6 | void f(int) = delete; // { dg-message "declared here" }
| ^
gcc/testsuite/g++.dg/cpp0x/deleted16.C:21:4: note: use
‘-fdiagnostics-all-candidates’ to display considered candidates
21 | f(0); // { dg-error "deleted" }
| ~^~~
gcc/testsuite/g++.dg/cpp0x/deleted16.C:22:4: error: use of deleted function
‘void g(int)’
22 | g(0); // { dg-error "deleted" }
| ~^~~
gcc/testsuite/g++.dg/cpp0x/deleted16.C:12:6: note: declared here
12 | void g(int) = delete; // { dg-message "declared here" }
| ^
gcc/testsuite/g++.dg/cpp0x/deleted16.C:22:4: note: use
‘-fdiagnostics-all-candidates’ to display considered candidates
22 | g(0); // { dg-error "deleted" }
| ~^~~
gcc/testsuite/g++.dg/cpp0x/deleted16.C:23:4: error: use of deleted function
‘void h(T, T) [with T = int]’
23 | h(1, 1); // { dg-error "deleted" }
| ~^~~~~~
gcc/testsuite/g++.dg/cpp0x/deleted16.C:17:24: note: declared here
17 | template<class T> void h(T, T) = delete; // { dg-message "declared
here|candidate" }
| ^
gcc/testsuite/g++.dg/cpp0x/deleted16.C:23:4: note: use
‘-fdiagnostics-all-candidates’ to display considered candidates
23 | h(1, 1); // { dg-error "deleted" }
| ~^~~~~~
-- >8 --
Subject: [PATCH 3/3] c++: note other candidates when diagnosing deletedness
With the previous two patches in place, we can now extend our
deletedness diagnostic to note the other considered candidates, e.g.:
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 controlled by a new command line flag
-fdiagnostics-all-candidates which also controls whether we note
ignored candidates more generally.
gcc/ChangeLog:
* doc/invoke.texi (C++ Dialect Options): Document
-fdiagnostics-all-candidates.
gcc/c-family/ChangeLog:
* c.opt: Add -fdiagnostics-all-candidates.
gcc/cp/ChangeLog:
* call.cc (print_z_candidates): Only print ignored candidates
when -fdiagnostics-all-candidates is set, otherwise suggest
the flag.
(build_over_call): When diagnosing deletedness, note
other candidates only if -fdiagnostics-all-candidates is
set, otherwise suggest the flag.
gcc/testsuite/ChangeLog:
* g++.dg/overload/error6.C: Pass -fdiagnostics-all-candidates.
* g++.dg/cpp0x/deleted16.C: New test.
* g++.dg/cpp0x/deleted16a.C: New test.
* g++.dg/overload/error6a.C: New test.
