| Message ID | 20240920184857.720642-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: CWG 2789 and reversed operator candidates | expand |
On 9/20/24 8:48 PM, Patrick Palka wrote: > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look > OK for trunk? OK. > -- >8 -- > > As a follow-up to r15-3741-gee3efe06c9c49c, which was only concerned > with usings, it seems we should also compare contexts of a reversed > vs non-reversed (member) candidate during operator overload > resolution. > > DR 2789 > > gcc/cp/ChangeLog: > > * call.cc (cand_parms_match): Check for matching class contexts > even in the reversed case. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/concepts-memfun4.C: Adjust expected result > involving reversed candidate. > --- > gcc/cp/call.cc | 11 +++++++---- > gcc/testsuite/g++.dg/cpp2a/concepts-memfun4.C | 6 +++--- > 2 files changed, 10 insertions(+), 7 deletions(-) > > diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc > index f2ce50857ec..70783baac24 100644 > --- a/gcc/cp/call.cc > +++ b/gcc/cp/call.cc > @@ -12865,10 +12865,6 @@ cand_parms_match (z_candidate *c1, z_candidate *c2, pmatch match_kind) > } > } > > - else if (reversed) > - return (reversed_match (c1, c2) > - && reversed_match (c2, c1)); > - > tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (fn1)); > tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (fn2)); > > @@ -12880,6 +12876,10 @@ cand_parms_match (z_candidate *c1, z_candidate *c2, pmatch match_kind) > if (base1 != base2) > return false; > > + if (reversed) > + return (reversed_match (c1, c2) > + && reversed_match (c2, c1)); > + > /* Use object_parms_correspond to simplify comparing iobj/xobj/static > member functions. */ > if (!object_parms_correspond (fn1, fn2, base1)) > @@ -12897,6 +12897,9 @@ cand_parms_match (z_candidate *c1, z_candidate *c2, pmatch match_kind) > parms1 = skip_parms (fn1, parms1); > parms2 = skip_parms (fn2, parms2); > } > + else if (reversed) > + return (reversed_match (c1, c2) > + && reversed_match (c2, c1)); > return compparms (parms1, parms2); > } > > diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-memfun4.C b/gcc/testsuite/g++.dg/cpp2a/concepts-memfun4.C > index cf7f13c007d..d849e9129a3 100644 > --- a/gcc/testsuite/g++.dg/cpp2a/concepts-memfun4.C > +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-memfun4.C > @@ -91,7 +91,7 @@ namespace N1 { > > A<> a; > B<> b; > - // when comparing the A op== to the reversed B op==, we compare them in > - // reverse order, so they match, and we choose the more constrained. > - static_assert (a == b); > + // A op== and B op== are defined in different classes so constraints > + // aren't considered, and the tie is broken via reversedness. > + static_assert (!(a == b)); > }
diff --git a/gcc/cp/call.cc b/gcc/cp/call.cc index f2ce50857ec..70783baac24 100644 --- a/gcc/cp/call.cc +++ b/gcc/cp/call.cc @@ -12865,10 +12865,6 @@ cand_parms_match (z_candidate *c1, z_candidate *c2, pmatch match_kind) } } - else if (reversed) - return (reversed_match (c1, c2) - && reversed_match (c2, c1)); - tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (fn1)); tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (fn2)); @@ -12880,6 +12876,10 @@ cand_parms_match (z_candidate *c1, z_candidate *c2, pmatch match_kind) if (base1 != base2) return false; + if (reversed) + return (reversed_match (c1, c2) + && reversed_match (c2, c1)); + /* Use object_parms_correspond to simplify comparing iobj/xobj/static member functions. */ if (!object_parms_correspond (fn1, fn2, base1)) @@ -12897,6 +12897,9 @@ cand_parms_match (z_candidate *c1, z_candidate *c2, pmatch match_kind) parms1 = skip_parms (fn1, parms1); parms2 = skip_parms (fn2, parms2); } + else if (reversed) + return (reversed_match (c1, c2) + && reversed_match (c2, c1)); return compparms (parms1, parms2); } diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-memfun4.C b/gcc/testsuite/g++.dg/cpp2a/concepts-memfun4.C index cf7f13c007d..d849e9129a3 100644 --- a/gcc/testsuite/g++.dg/cpp2a/concepts-memfun4.C +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-memfun4.C @@ -91,7 +91,7 @@ namespace N1 { A<> a; B<> b; - // when comparing the A op== to the reversed B op==, we compare them in - // reverse order, so they match, and we choose the more constrained. - static_assert (a == b); + // A op== and B op== are defined in different classes so constraints + // aren't considered, and the tie is broken via reversedness. + static_assert (!(a == b)); }