r8-1253-g3d2e25a240c711 removed the template argument linkage requirement in convert_nontype_argument for C++17, but we need to also remove the one in convert_nontype_argument_function for sake of the first and third test case which we incorrectly reject (in C++17/20 mode).
And in invalid_tparm_referent_p we're inadvertendly rejecting using the address of a lambda's static op() due to the DECL_ARTIFICIAL check. This patch relaxes this check for sake of the second test case which we incorrectly reject (in C++20 mode). Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk and perhaps 13 (since it's a relatively easy/safe fix for a popular non-regression bug). Co-authored-by: Jonathan Wakely <jwak...@redhat.com> PR c++/83258 PR c++/80488 PR c++/97700 gcc/cp/ChangeLog: * pt.cc (convert_nontype_argument_function): Disable linkage requirement for C++17 and later. (invalid_tparm_referent_p): Relax DECL_ARTIFICIAL check for the artificial static op() of a lambda. gcc/testsuite/ChangeLog: * g++.dg/ext/visibility/anon8.C: Don't expect a "no linkage" error for the template argument &B2:fn in C++17 mode. * g++.dg/cpp0x/lambda/lambda-conv15.C: New test. * g++.dg/cpp2a/nontype-class56.C: New test. * g++.dg/template/function2.C: New test. --- gcc/cp/pt.cc | 7 +++++-- gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C | 11 +++++++++++ gcc/testsuite/g++.dg/cpp2a/nontype-class56.C | 8 ++++++++ gcc/testsuite/g++.dg/ext/visibility/anon8.C | 4 ++-- gcc/testsuite/g++.dg/template/function2.C | 8 ++++++++ 5 files changed, 34 insertions(+), 4 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/nontype-class56.C create mode 100644 gcc/testsuite/g++.dg/template/function2.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 696df2bdd9f..c9b089f8fa7 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -6782,7 +6782,8 @@ convert_nontype_argument_function (tree type, tree expr, } linkage = decl_linkage (fn_no_ptr); - if (cxx_dialect >= cxx11 ? linkage == lk_none : linkage != lk_external) + if ((cxx_dialect < cxx11 && linkage != lk_external) + || (cxx_dialect < cxx17 && linkage == lk_none)) { if (complain & tf_error) { @@ -7180,7 +7181,9 @@ invalid_tparm_referent_p (tree type, tree expr, tsubst_flags_t complain) * a string literal (5.13.5), * the result of a typeid expression (8.2.8), or * a predefined __func__ variable (11.4.1). */ - else if (DECL_ARTIFICIAL (decl)) + else if (DECL_ARTIFICIAL (decl) + /* Accept the artificial static op() of a lambda. */ + && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (decl))) { if (complain & tf_error) error ("the address of %qD is not a valid template argument", diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C new file mode 100644 index 00000000000..cf45e06a33d --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-conv15.C @@ -0,0 +1,11 @@ +// PR c++/83258 +// PR c++/80488 +// { dg-do compile { target c++11 } } + +template<void(*)()> struct A { }; + +int main() { + constexpr auto fp = +[]{}; // { dg-error "non-'constexpr' function" "" { target c++14_down } } + A<fp> a1; // { dg-error "not a valid template argument" "" { target c++14_down } } + A<[]{}> a2; // { dg-error "lambda-expression in template-argument|invalid" "" { target c++17_down } } +} diff --git a/gcc/testsuite/g++.dg/cpp2a/nontype-class56.C b/gcc/testsuite/g++.dg/cpp2a/nontype-class56.C new file mode 100644 index 00000000000..0efd735c8a3 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/nontype-class56.C @@ -0,0 +1,8 @@ +// PR c++/97700 +// { dg-do compile { target c++20 } } + +struct S { void (*f)(); }; + +template<S> struct X { }; + +X<S{[]{}}> x; diff --git a/gcc/testsuite/g++.dg/ext/visibility/anon8.C b/gcc/testsuite/g++.dg/ext/visibility/anon8.C index b8507497d32..bfcc2d06df6 100644 --- a/gcc/testsuite/g++.dg/ext/visibility/anon8.C +++ b/gcc/testsuite/g++.dg/ext/visibility/anon8.C @@ -2,7 +2,7 @@ // { dg-do compile } template <void (*fn) ()> -void call () // { dg-message "note" } +void call () // { dg-message "note" "" { target c++14_down } } { fn (); } @@ -26,7 +26,7 @@ int main () static void fn2 () {} }; call<&B1::fn1> (); - call<&B2::fn2> (); // { dg-error "linkage|no matching" } + call<&B2::fn2> (); // { dg-error "linkage|no matching" "" { target c++14_down } } call<&fn3> (); call<&B1::fn4> (); call<&fn5> (); // { dg-error "linkage|no matching" "" { target { ! c++11 } } } diff --git a/gcc/testsuite/g++.dg/template/function2.C b/gcc/testsuite/g++.dg/template/function2.C new file mode 100644 index 00000000000..ad19f24c1cd --- /dev/null +++ b/gcc/testsuite/g++.dg/template/function2.C @@ -0,0 +1,8 @@ +// PR c++/83258 + +template<void(*)()> struct A { }; + +int main() { + struct B { static void f(); }; + A<B::f> a; // { dg-error "linkage" "" { target c++14_down } } +} -- 2.40.1.476.g69c786637d