In explicit17.C, we weren't detecting an unexpanded parameter pack in explicit(bool), so we crashed on a TEMPLATE_PARM_INDEX in constexpr.
I noticed the same is true for noexcept(), but only since my patch to implement delayed parsing of noexcept. Previously, we would detect the unexpanded pack in push_template_decl but now the noexcept expression has not yet been parsed, so we need to do it a bit later. Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? gcc/cp/ChangeLog: PR c++/99844 * decl.c (build_explicit_specifier): Call check_for_bare_parameter_packs. * except.c (build_noexcept_spec): Likewise. gcc/testsuite/ChangeLog: PR c++/99844 * g++.dg/cpp2a/explicit16.C: Use c++20. * g++.dg/cpp0x/noexcept66.C: New test. * g++.dg/cpp2a/explicit17.C: New test. --- gcc/cp/decl.c | 3 +++ gcc/cp/except.c | 2 ++ gcc/testsuite/g++.dg/cpp0x/noexcept66.C | 13 +++++++++++++ gcc/testsuite/g++.dg/cpp2a/explicit16.C | 2 +- gcc/testsuite/g++.dg/cpp2a/explicit17.C | 9 +++++++++ 5 files changed, 28 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/noexcept66.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/explicit17.C diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c index edab147c78d..3294b4fa943 100644 --- a/gcc/cp/decl.c +++ b/gcc/cp/decl.c @@ -17991,6 +17991,9 @@ require_deduced_type (tree decl, tsubst_flags_t complain) tree build_explicit_specifier (tree expr, tsubst_flags_t complain) { + if (check_for_bare_parameter_packs (expr)) + return error_mark_node; + if (instantiation_dependent_expression_p (expr)) /* Wait for instantiation, tsubst_function_decl will handle it. */ return expr; diff --git a/gcc/cp/except.c b/gcc/cp/except.c index 0bbc229490e..cbafc09629b 100644 --- a/gcc/cp/except.c +++ b/gcc/cp/except.c @@ -1228,6 +1228,8 @@ type_throw_all_p (const_tree type) tree build_noexcept_spec (tree expr, tsubst_flags_t complain) { + if (check_for_bare_parameter_packs (expr)) + return error_mark_node; if (TREE_CODE (expr) != DEFERRED_NOEXCEPT && !value_dependent_expression_p (expr)) { diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept66.C b/gcc/testsuite/g++.dg/cpp0x/noexcept66.C new file mode 100644 index 00000000000..6c76d9146ad --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/noexcept66.C @@ -0,0 +1,13 @@ +// PR c++/99844 +// { dg-do compile { target c++11 } } + +template <bool... B> +struct S { + void fn() noexcept(B); // { dg-error "parameter packs not expanded" } +}; + +void fn () +{ + S<true> s; + s.fn(); +} diff --git a/gcc/testsuite/g++.dg/cpp2a/explicit16.C b/gcc/testsuite/g++.dg/cpp2a/explicit16.C index 9d95b0d669e..9c20f6332e9 100644 --- a/gcc/testsuite/g++.dg/cpp2a/explicit16.C +++ b/gcc/testsuite/g++.dg/cpp2a/explicit16.C @@ -1,5 +1,5 @@ // PR c++/95066 - explicit malfunction with dependent expression. -// { dg-do compile { target c++2a } } +// { dg-do compile { target c++20 } } template <typename T> struct Foo { diff --git a/gcc/testsuite/g++.dg/cpp2a/explicit17.C b/gcc/testsuite/g++.dg/cpp2a/explicit17.C new file mode 100644 index 00000000000..38a61f4a273 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/explicit17.C @@ -0,0 +1,9 @@ +// PR c++/99844 +// { dg-do compile { target c++20 } } + +template <bool... B> +struct S { + constexpr explicit(B) S() {} // { dg-error "parameter packs not expanded" } +}; + +constexpr S<true> s; base-commit: 2f3d9104610cb2058cf091707a20c1c6eff8d470 -- 2.30.2