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. gcc/testsuite/ChangeLog: * g++.dg/overload/error6.C: Pass -fnote-all-cands. * g++.dg/cpp0x/deleted16.C: New test. --- gcc/c-family/c.opt | 4 ++++ gcc/cp/call.cc | 8 +++++++- gcc/doc/invoke.texi | 5 +++++ gcc/testsuite/g++.dg/cpp0x/deleted16.C | 25 +++++++++++++++++++++++++ gcc/testsuite/g++.dg/overload/error6.C | 1 + 5 files changed, 42 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/deleted16.C diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt index 44b9c862c14..a76f73cc661 100644 --- a/gcc/c-family/c.opt +++ b/gcc/c-family/c.opt @@ -2006,6 +2006,10 @@ fnil-receivers ObjC ObjC++ Var(flag_nil_receivers) Init(1) Assume that receivers of Objective-C messages may be nil. +fnote-all-cands +C++ ObjC++ Var(flag_note_all_cands) +Note all candidates during overload resolution failure. + flocal-ivars ObjC ObjC++ Var(flag_local_ivars) Init(1) Allow access to instance variables as if they were local declarations within instance method implementations. diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index 81cc029dddb..7ace0e65096 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -4090,6 +4090,8 @@ print_z_candidates (location_t loc, struct z_candidate *candidates, { if (only_viable_p.is_true () && candidates->viable != 1) break; + if (ignored_candidate_p (candidates) && !flag_note_all_cands) + break; print_z_candidate (loc, N_("candidate:"), candidates); } } @@ -9933,7 +9935,11 @@ 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); + if (cand->next && flag_note_all_cands) + print_z_candidates (input_location, cand, /*only_viable_p=*/false); + } return error_mark_node; } diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 5a9284d635c..ac82299416c 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -3479,6 +3479,11 @@ Disable built-in declarations of functions that are not mandated by ANSI/ISO C@. These include @code{ffs}, @code{alloca}, @code{_exit}, @code{index}, @code{bzero}, @code{conjf}, and other related functions. +@opindex fnote-all-cands +@item -fnote-all-cands +Permit the C++ front end to note all candidates during overload resolution +failure, including when a deleted function is selected. + @opindex fnothrow-opt @item -fnothrow-opt Treat a @code{throw()} exception specification as if it were a diff --git a/gcc/testsuite/g++.dg/cpp0x/deleted16.C b/gcc/testsuite/g++.dg/cpp0x/deleted16.C new file mode 100644 index 00000000000..506caae76b6 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/deleted16.C @@ -0,0 +1,25 @@ +// Verify -fnote-all-cands causes us to note other candidates when a deleted +// function is selected by overload resolution. +// { dg-do compile { target c++11 } } +// { dg-additional-options "-fnote-all-cands" } + +void f(int) = delete; // { dg-message "declared here|candidate" } +void f(...); // { dg-message "candidate" } +void f(int, int); // { dg-message "candidate" } + +// An example where the perfect candidate optimization causes us +// to ignore function templates. +void g(int) = delete; // { dg-message "declared here|candidate" } +template<class T> void g(T); // { dg-message "candidate" } + +// An example where we have a strictly viable candidate and +// an incompletely considered bad candidate. +template<class T> void h(T, T) = delete; // { dg-message "declared here|candidate" } +void h(int*, int) = delete; // { dg-message "candidate" } + +int main() { + f(0); // { dg-error "deleted" } + g(0); // { dg-error "deleted" } + h(1, 1); // { dg-error "deleted" } + // { dg-error "invalid conversion" "" { target *-*-* } .-1 } when noting 2nd cand +} diff --git a/gcc/testsuite/g++.dg/overload/error6.C b/gcc/testsuite/g++.dg/overload/error6.C index 86a12eaa8de..ac513824887 100644 --- a/gcc/testsuite/g++.dg/overload/error6.C +++ b/gcc/testsuite/g++.dg/overload/error6.C @@ -1,5 +1,6 @@ // Verify we note even non-template candidates when diagnosing // overload resolution failure for a template-id. +// { dg-additional-options "-fnote-all-cands" } template<class T> void f(T); // { dg-message "candidate" } void f(int); // { dg-message {candidate: 'void f\(int\)' \(ignored\)} } -- 2.42.0.482.g2e8e77cbac