| Message ID | 20230518175927.4158045-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: scoped variable template-id of reference type [PR97340] | expand |
On 5/18/23 13:59, Patrick Palka wrote: > lookup_and_finish_template_variable calls convert_from_reference, which > means for a variable template-id of reference type the function returns > an INDIRECT_REF instead of the bare VAR_DECL. But the downstream logic > of two callers, tsubst_qualified_id and finish_class_member_access_expr, > expect a DECL_P result and so we end up crashing when resolving the > template-id's in the first testcase. (Note that these two callers > eventually call convert_from_reference as appropriate, so this earlier > call seems at best redundant.) > > This patch fixes this by pulling out the convert_from_reference call > from lookup_and_finish_template_variable and into the callers that > actually need it, which turns out to be tsubst_copy_and_build (without > it we'd mishandle the second testcase). > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > trunk? OK. > PR c++/97340 > > gcc/cp/ChangeLog: > > * pt.cc (lookup_and_finish_template_variable): Don't call > convert_from_reference. > (tsubst_copy_and_build) <case TEMPLATE_ID_EXPR>: Call > convert_from_reference on the result of > lookup_and_finish_template_variable. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp1y/var-templ80.C: New test. > * g++.dg/cpp1y/var-templ81.C: New test. > --- > gcc/cp/pt.cc | 3 ++- > gcc/testsuite/g++.dg/cpp1y/var-templ80.C | 22 ++++++++++++++++++++++ > gcc/testsuite/g++.dg/cpp1y/var-templ81.C | 14 ++++++++++++++ > 3 files changed, 38 insertions(+), 1 deletion(-) > create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ80.C > create mode 100644 gcc/testsuite/g++.dg/cpp1y/var-templ81.C > > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc > index 351fc18b600..9e5b29f3099 100644 > --- a/gcc/cp/pt.cc > +++ b/gcc/cp/pt.cc > @@ -10394,7 +10394,7 @@ lookup_and_finish_template_variable (tree templ, tree targs, > complain &= ~tf_partial; > var = finish_template_variable (var, complain); > mark_used (var); > - return convert_from_reference (var); > + return var; > } > > /* If the set of template parameters PARMS contains a template parameter > @@ -20462,6 +20462,7 @@ tsubst_copy_and_build (tree t, > { > tree r = lookup_and_finish_template_variable (templ, targs, > complain); > + r = convert_from_reference (r); > r = maybe_wrap_with_location (r, EXPR_LOCATION (t)); > RETURN (r); > } > diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ80.C b/gcc/testsuite/g++.dg/cpp1y/var-templ80.C > new file mode 100644 > index 00000000000..4439bee8292 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ80.C > @@ -0,0 +1,22 @@ > +// PR c++/97340 > +// { dg-do compile { target c++14 } } > + > +template<class> > +struct A { > + template<class> > + static constexpr const int& var = 0; > +}; > + > +template<class T> > +struct B { > + static constexpr int x1 = A<T>::template var<int>; > + static constexpr int y1 = A<T>{}.template var<int>; > + > + static constexpr int x2 = A<int>::template var<T>; > + static constexpr int y2 = A<int>{}.template var<T>; > + > + static constexpr int x3 = A<int>::template var<int>; > + static constexpr int y3 = A<int>{}.template var<int>; > +}; > + > +template struct B<int>; > diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ81.C b/gcc/testsuite/g++.dg/cpp1y/var-templ81.C > new file mode 100644 > index 00000000000..f9d2e6b1eed > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ81.C > @@ -0,0 +1,14 @@ > +// Verify we don't ICE on an invalid use of unary * for a variable > +// template-id of reference type. > +// { dg-do compile { target c++14 } } > + > +template<class> > +static constexpr const int& var = 0; > + > +template<class T> > +struct B { > + static constexpr int x = *var<T>; // { dg-error "argument of unary" } > + static constexpr const int& y = *var<T>; // { dg-error "argument of unary" } > +}; > + > +template struct B<int>;
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 351fc18b600..9e5b29f3099 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -10394,7 +10394,7 @@ lookup_and_finish_template_variable (tree templ, tree targs, complain &= ~tf_partial; var = finish_template_variable (var, complain); mark_used (var); - return convert_from_reference (var); + return var; } /* If the set of template parameters PARMS contains a template parameter @@ -20462,6 +20462,7 @@ tsubst_copy_and_build (tree t, { tree r = lookup_and_finish_template_variable (templ, targs, complain); + r = convert_from_reference (r); r = maybe_wrap_with_location (r, EXPR_LOCATION (t)); RETURN (r); } diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ80.C b/gcc/testsuite/g++.dg/cpp1y/var-templ80.C new file mode 100644 index 00000000000..4439bee8292 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ80.C @@ -0,0 +1,22 @@ +// PR c++/97340 +// { dg-do compile { target c++14 } } + +template<class> +struct A { + template<class> + static constexpr const int& var = 0; +}; + +template<class T> +struct B { + static constexpr int x1 = A<T>::template var<int>; + static constexpr int y1 = A<T>{}.template var<int>; + + static constexpr int x2 = A<int>::template var<T>; + static constexpr int y2 = A<int>{}.template var<T>; + + static constexpr int x3 = A<int>::template var<int>; + static constexpr int y3 = A<int>{}.template var<int>; +}; + +template struct B<int>; diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ81.C b/gcc/testsuite/g++.dg/cpp1y/var-templ81.C new file mode 100644 index 00000000000..f9d2e6b1eed --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ81.C @@ -0,0 +1,14 @@ +// Verify we don't ICE on an invalid use of unary * for a variable +// template-id of reference type. +// { dg-do compile { target c++14 } } + +template<class> +static constexpr const int& var = 0; + +template<class T> +struct B { + static constexpr int x = *var<T>; // { dg-error "argument of unary" } + static constexpr const int& y = *var<T>; // { dg-error "argument of unary" } +}; + +template struct B<int>;