| Message ID | 20210715163718.1707452-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: covariant reference return type [PR99664] | expand |
On 7/15/21 12:37 PM, Patrick Palka wrote: > This implements the wording changes of DR 960 which clarifies that two > reference types are covariant only if they're both lvalue references > or both rvalue references. > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look > OK for trunk? OK. > DR 960 > PR c++/99664 > > gcc/cp/ChangeLog: > > * search.c (check_final_overrider): Compare TYPE_REF_IS_RVALUE > when the return types are references. > > gcc/testsuite/ChangeLog: > > * g++.dg/inherit/covariant23.C: New test. > --- > gcc/cp/search.c | 8 +++++++- > gcc/testsuite/g++.dg/inherit/covariant23.C | 14 ++++++++++++++ > 2 files changed, 21 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/inherit/covariant23.C > > diff --git a/gcc/cp/search.c b/gcc/cp/search.c > index af41bfe5835..943671acff8 100644 > --- a/gcc/cp/search.c > +++ b/gcc/cp/search.c > @@ -1948,7 +1948,13 @@ check_final_overrider (tree overrider, tree basefn) > fail = !INDIRECT_TYPE_P (base_return); > if (!fail) > { > - fail = cp_type_quals (base_return) != cp_type_quals (over_return); > + if (cp_type_quals (base_return) != cp_type_quals (over_return)) > + fail = 1; > + > + if (TYPE_REF_P (base_return) > + && (TYPE_REF_IS_RVALUE (base_return) > + != TYPE_REF_IS_RVALUE (over_return))) > + fail = 1; > > base_return = TREE_TYPE (base_return); > over_return = TREE_TYPE (over_return); > diff --git a/gcc/testsuite/g++.dg/inherit/covariant23.C b/gcc/testsuite/g++.dg/inherit/covariant23.C > new file mode 100644 > index 00000000000..b27be15ef45 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/inherit/covariant23.C > @@ -0,0 +1,14 @@ > +// PR c++/99664 > +// { dg-do compile { target c++11 } } > + > +struct Res { }; > + > +struct A { > + virtual Res &&f(); > + virtual Res &g(); > +}; > + > +struct B : A { > + Res &f() override; // { dg-error "return type" } > + Res &&g() override; // { dg-error "return type" } > +}; >
diff --git a/gcc/cp/search.c b/gcc/cp/search.c index af41bfe5835..943671acff8 100644 --- a/gcc/cp/search.c +++ b/gcc/cp/search.c @@ -1948,7 +1948,13 @@ check_final_overrider (tree overrider, tree basefn) fail = !INDIRECT_TYPE_P (base_return); if (!fail) { - fail = cp_type_quals (base_return) != cp_type_quals (over_return); + if (cp_type_quals (base_return) != cp_type_quals (over_return)) + fail = 1; + + if (TYPE_REF_P (base_return) + && (TYPE_REF_IS_RVALUE (base_return) + != TYPE_REF_IS_RVALUE (over_return))) + fail = 1; base_return = TREE_TYPE (base_return); over_return = TREE_TYPE (over_return); diff --git a/gcc/testsuite/g++.dg/inherit/covariant23.C b/gcc/testsuite/g++.dg/inherit/covariant23.C new file mode 100644 index 00000000000..b27be15ef45 --- /dev/null +++ b/gcc/testsuite/g++.dg/inherit/covariant23.C @@ -0,0 +1,14 @@ +// PR c++/99664 +// { dg-do compile { target c++11 } } + +struct Res { }; + +struct A { + virtual Res &&f(); + virtual Res &g(); +}; + +struct B : A { + Res &f() override; // { dg-error "return type" } + Res &&g() override; // { dg-error "return type" } +};