| Message ID | 20231027195532.2566822-3-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3,1/3] c++: sort candidates according to viability | expand |
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 Maybe "-fdiagnostics-all-candidates"? Jason
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. --- gcc/c-family/c.opt | 4 ++++ gcc/cp/call.cc | 19 ++++++++++++++++++- gcc/doc/invoke.texi | 5 +++++ gcc/testsuite/g++.dg/cpp0x/deleted16.C | 25 +++++++++++++++++++++++++ gcc/testsuite/g++.dg/cpp0x/deleted16a.C | 12 ++++++++++++ gcc/testsuite/g++.dg/overload/error6.C | 1 + gcc/testsuite/g++.dg/overload/error6a.C | 6 ++++++ 7 files changed, 71 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/deleted16.C create mode 100644 gcc/testsuite/g++.dg/cpp0x/deleted16a.C create mode 100644 gcc/testsuite/g++.dg/overload/error6a.C diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt index 44b9c862c14..c12c86bb8ed 100644 --- a/gcc/c-family/c.opt +++ b/gcc/c-family/c.opt @@ -1781,6 +1781,10 @@ fdiagnostics-show-template-tree C++ ObjC++ Var(flag_diagnostics_show_template_tree) Init(0) Print hierarchical comparisons when template types are mismatched. +fdiagnostics-all-candidates +C++ ObjC++ Var(flag_diagnostics_all_candidates) +Note all candidates during overload resolution failure. + fdirectives-only C ObjC C++ ObjC++ Preprocess directives only. diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index 81cc029dddb..e9c099eedb8 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -4090,6 +4090,12 @@ 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_diagnostics_all_candidates) + { + inform (loc, "some candidates omitted; " + "use %<-fdiagnostics-all-candidates%> to display them"); + break; + } print_z_candidate (loc, N_("candidate:"), candidates); } } @@ -9933,7 +9939,18 @@ 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) + { + if (flag_diagnostics_all_candidates) + print_z_candidates (input_location, cand, /*only_viable_p=*/false); + else + inform (input_location, + "use %<-fdiagnostics-all-candidates%> to display " + "considered candidates"); + } + } return error_mark_node; } diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 5a9284d635c..7e9f68d31b3 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -3311,6 +3311,11 @@ called. If the handler returns, execution continues normally. @item -fcoroutines Enable support for the C++ coroutines extension (experimental). +@opindex fdiagnostics-all-candidates +@item -fdiagnostics-all-candidates +Permit the C++ front end to note all candidates during overload resolution +failure, including when a deleted function is selected. + @opindex fno-elide-constructors @opindex felide-constructors @item -fno-elide-constructors diff --git a/gcc/testsuite/g++.dg/cpp0x/deleted16.C b/gcc/testsuite/g++.dg/cpp0x/deleted16.C new file mode 100644 index 00000000000..d4347942c42 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/deleted16.C @@ -0,0 +1,25 @@ +// Verify -fdiagnostics-all-candidates makes us note other candidates +// when a deleted function is selected by overload resolution. +// { dg-do compile { target c++11 } } +// { dg-additional-options "-fdiagnostics-all-candidates" } + +void f(int) = delete; // { dg-message "declared here" } +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" } +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/cpp0x/deleted16a.C b/gcc/testsuite/g++.dg/cpp0x/deleted16a.C new file mode 100644 index 00000000000..e62306fa3d1 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/deleted16a.C @@ -0,0 +1,12 @@ +// Verify we suggest -fdiagnostics-all-candidates when diagnosing +// overload resolution selecting a deleted function. +// { dg-do compile { target c++11 } } +#include "deleted16.C" + +// { dg-error "deleted" "" { target *-*-* } 21 } +// { dg-error "deleted" "" { target *-*-* } 22 } +// { dg-error "deleted" "" { target *-*-* } 23 } + +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 21 } +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 22 } +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 23 } diff --git a/gcc/testsuite/g++.dg/overload/error6.C b/gcc/testsuite/g++.dg/overload/error6.C index 86a12eaa8de..3186a297bfc 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 "-fdiagnostics-all-candidates" } template<class T> void f(T); // { dg-message "candidate" } void f(int); // { dg-message {candidate: 'void f\(int\)' \(ignored\)} } diff --git a/gcc/testsuite/g++.dg/overload/error6a.C b/gcc/testsuite/g++.dg/overload/error6a.C new file mode 100644 index 00000000000..e86ab5158ab --- /dev/null +++ b/gcc/testsuite/g++.dg/overload/error6a.C @@ -0,0 +1,6 @@ +// Verify we suggest -fdiagnostics-all-candidates when there are +// omitted candidates. +#include "error6.C" + +// { dg-error "no match" "" { target *-*-* } 9 } +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 9 }
On Fri, 27 Oct 2023, Patrick Palka wrote: > 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. It just occurred to me that this despite this flag being C++ specific, it probably should be documented under "Diagnostic Message Formatting Options", like -fdiagnostics-show-template-tree is. > > > > > > 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. > --- > gcc/c-family/c.opt | 4 ++++ > gcc/cp/call.cc | 19 ++++++++++++++++++- > gcc/doc/invoke.texi | 5 +++++ > gcc/testsuite/g++.dg/cpp0x/deleted16.C | 25 +++++++++++++++++++++++++ > gcc/testsuite/g++.dg/cpp0x/deleted16a.C | 12 ++++++++++++ > gcc/testsuite/g++.dg/overload/error6.C | 1 + > gcc/testsuite/g++.dg/overload/error6a.C | 6 ++++++ > 7 files changed, 71 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp0x/deleted16.C > create mode 100644 gcc/testsuite/g++.dg/cpp0x/deleted16a.C > create mode 100644 gcc/testsuite/g++.dg/overload/error6a.C > > diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt > index 44b9c862c14..c12c86bb8ed 100644 > --- a/gcc/c-family/c.opt > +++ b/gcc/c-family/c.opt > @@ -1781,6 +1781,10 @@ fdiagnostics-show-template-tree > C++ ObjC++ Var(flag_diagnostics_show_template_tree) Init(0) > Print hierarchical comparisons when template types are mismatched. > > +fdiagnostics-all-candidates > +C++ ObjC++ Var(flag_diagnostics_all_candidates) > +Note all candidates during overload resolution failure. > + > fdirectives-only > C ObjC C++ ObjC++ > Preprocess directives only. > diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc > index 81cc029dddb..e9c099eedb8 100644 > --- a/gcc/cp/call.cc > +++ b/gcc/cp/call.cc > @@ -4090,6 +4090,12 @@ 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_diagnostics_all_candidates) > + { > + inform (loc, "some candidates omitted; " > + "use %<-fdiagnostics-all-candidates%> to display them"); > + break; > + } > print_z_candidate (loc, N_("candidate:"), candidates); > } > } > @@ -9933,7 +9939,18 @@ 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) > + { > + if (flag_diagnostics_all_candidates) > + print_z_candidates (input_location, cand, /*only_viable_p=*/false); > + else > + inform (input_location, > + "use %<-fdiagnostics-all-candidates%> to display " > + "considered candidates"); > + } > + } > return error_mark_node; > } > > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > index 5a9284d635c..7e9f68d31b3 100644 > --- a/gcc/doc/invoke.texi > +++ b/gcc/doc/invoke.texi > @@ -3311,6 +3311,11 @@ called. If the handler returns, execution continues normally. > @item -fcoroutines > Enable support for the C++ coroutines extension (experimental). > > +@opindex fdiagnostics-all-candidates > +@item -fdiagnostics-all-candidates > +Permit the C++ front end to note all candidates during overload resolution > +failure, including when a deleted function is selected. > + > @opindex fno-elide-constructors > @opindex felide-constructors > @item -fno-elide-constructors > diff --git a/gcc/testsuite/g++.dg/cpp0x/deleted16.C b/gcc/testsuite/g++.dg/cpp0x/deleted16.C > new file mode 100644 > index 00000000000..d4347942c42 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/deleted16.C > @@ -0,0 +1,25 @@ > +// Verify -fdiagnostics-all-candidates makes us note other candidates > +// when a deleted function is selected by overload resolution. > +// { dg-do compile { target c++11 } } > +// { dg-additional-options "-fdiagnostics-all-candidates" } > + > +void f(int) = delete; // { dg-message "declared here" } > +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" } > +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/cpp0x/deleted16a.C b/gcc/testsuite/g++.dg/cpp0x/deleted16a.C > new file mode 100644 > index 00000000000..e62306fa3d1 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/deleted16a.C > @@ -0,0 +1,12 @@ > +// Verify we suggest -fdiagnostics-all-candidates when diagnosing > +// overload resolution selecting a deleted function. > +// { dg-do compile { target c++11 } } > +#include "deleted16.C" > + > +// { dg-error "deleted" "" { target *-*-* } 21 } > +// { dg-error "deleted" "" { target *-*-* } 22 } > +// { dg-error "deleted" "" { target *-*-* } 23 } > + > +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 21 } > +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 22 } > +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 23 } > diff --git a/gcc/testsuite/g++.dg/overload/error6.C b/gcc/testsuite/g++.dg/overload/error6.C > index 86a12eaa8de..3186a297bfc 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 "-fdiagnostics-all-candidates" } > > template<class T> void f(T); // { dg-message "candidate" } > void f(int); // { dg-message {candidate: 'void f\(int\)' \(ignored\)} } > diff --git a/gcc/testsuite/g++.dg/overload/error6a.C b/gcc/testsuite/g++.dg/overload/error6a.C > new file mode 100644 > index 00000000000..e86ab5158ab > --- /dev/null > +++ b/gcc/testsuite/g++.dg/overload/error6a.C > @@ -0,0 +1,6 @@ > +// Verify we suggest -fdiagnostics-all-candidates when there are > +// omitted candidates. > +#include "error6.C" > + > +// { dg-error "no match" "" { target *-*-* } 9 } > +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 9 } > -- > 2.42.0.482.g2e8e77cbac >
On Fri, 27 Oct 2023, Patrick Palka wrote: > 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. Ping. > --- > gcc/c-family/c.opt | 4 ++++ > gcc/cp/call.cc | 19 ++++++++++++++++++- > gcc/doc/invoke.texi | 5 +++++ > gcc/testsuite/g++.dg/cpp0x/deleted16.C | 25 +++++++++++++++++++++++++ > gcc/testsuite/g++.dg/cpp0x/deleted16a.C | 12 ++++++++++++ > gcc/testsuite/g++.dg/overload/error6.C | 1 + > gcc/testsuite/g++.dg/overload/error6a.C | 6 ++++++ > 7 files changed, 71 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp0x/deleted16.C > create mode 100644 gcc/testsuite/g++.dg/cpp0x/deleted16a.C > create mode 100644 gcc/testsuite/g++.dg/overload/error6a.C > > diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt > index 44b9c862c14..c12c86bb8ed 100644 > --- a/gcc/c-family/c.opt > +++ b/gcc/c-family/c.opt > @@ -1781,6 +1781,10 @@ fdiagnostics-show-template-tree > C++ ObjC++ Var(flag_diagnostics_show_template_tree) Init(0) > Print hierarchical comparisons when template types are mismatched. > > +fdiagnostics-all-candidates > +C++ ObjC++ Var(flag_diagnostics_all_candidates) > +Note all candidates during overload resolution failure. > + > fdirectives-only > C ObjC C++ ObjC++ > Preprocess directives only. > diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc > index 81cc029dddb..e9c099eedb8 100644 > --- a/gcc/cp/call.cc > +++ b/gcc/cp/call.cc > @@ -4090,6 +4090,12 @@ 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_diagnostics_all_candidates) > + { > + inform (loc, "some candidates omitted; " > + "use %<-fdiagnostics-all-candidates%> to display them"); > + break; > + } > print_z_candidate (loc, N_("candidate:"), candidates); > } > } > @@ -9933,7 +9939,18 @@ 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) > + { > + if (flag_diagnostics_all_candidates) > + print_z_candidates (input_location, cand, /*only_viable_p=*/false); > + else > + inform (input_location, > + "use %<-fdiagnostics-all-candidates%> to display " > + "considered candidates"); > + } > + } > return error_mark_node; > } > > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > index 5a9284d635c..7e9f68d31b3 100644 > --- a/gcc/doc/invoke.texi > +++ b/gcc/doc/invoke.texi > @@ -3311,6 +3311,11 @@ called. If the handler returns, execution continues normally. > @item -fcoroutines > Enable support for the C++ coroutines extension (experimental). > > +@opindex fdiagnostics-all-candidates > +@item -fdiagnostics-all-candidates > +Permit the C++ front end to note all candidates during overload resolution > +failure, including when a deleted function is selected. > + > @opindex fno-elide-constructors > @opindex felide-constructors > @item -fno-elide-constructors > diff --git a/gcc/testsuite/g++.dg/cpp0x/deleted16.C b/gcc/testsuite/g++.dg/cpp0x/deleted16.C > new file mode 100644 > index 00000000000..d4347942c42 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/deleted16.C > @@ -0,0 +1,25 @@ > +// Verify -fdiagnostics-all-candidates makes us note other candidates > +// when a deleted function is selected by overload resolution. > +// { dg-do compile { target c++11 } } > +// { dg-additional-options "-fdiagnostics-all-candidates" } > + > +void f(int) = delete; // { dg-message "declared here" } > +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" } > +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/cpp0x/deleted16a.C b/gcc/testsuite/g++.dg/cpp0x/deleted16a.C > new file mode 100644 > index 00000000000..e62306fa3d1 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp0x/deleted16a.C > @@ -0,0 +1,12 @@ > +// Verify we suggest -fdiagnostics-all-candidates when diagnosing > +// overload resolution selecting a deleted function. > +// { dg-do compile { target c++11 } } > +#include "deleted16.C" > + > +// { dg-error "deleted" "" { target *-*-* } 21 } > +// { dg-error "deleted" "" { target *-*-* } 22 } > +// { dg-error "deleted" "" { target *-*-* } 23 } > + > +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 21 } > +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 22 } > +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 23 } > diff --git a/gcc/testsuite/g++.dg/overload/error6.C b/gcc/testsuite/g++.dg/overload/error6.C > index 86a12eaa8de..3186a297bfc 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 "-fdiagnostics-all-candidates" } > > template<class T> void f(T); // { dg-message "candidate" } > void f(int); // { dg-message {candidate: 'void f\(int\)' \(ignored\)} } > diff --git a/gcc/testsuite/g++.dg/overload/error6a.C b/gcc/testsuite/g++.dg/overload/error6a.C > new file mode 100644 > index 00000000000..e86ab5158ab > --- /dev/null > +++ b/gcc/testsuite/g++.dg/overload/error6a.C > @@ -0,0 +1,6 @@ > +// Verify we suggest -fdiagnostics-all-candidates when there are > +// omitted candidates. > +#include "error6.C" > + > +// { dg-error "no match" "" { target *-*-* } 9 } > +// { dg-message "use '-fdiagnostics-all-candidates'" "" { target *-*-* } 9 } > -- > 2.42.0.482.g2e8e77cbac >
On 11/30/23 10:46, Patrick Palka wrote: > On Fri, 27 Oct 2023, Patrick Palka wrote: >> 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. > > Ping. OK. Jason
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\(int\)' \(ignored\)} }
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