https://gcc.gnu.org/g:dc6c3bfb59baab28b998e18396c06087b6d9b0ed
commit r14-9339-gdc6c3bfb59baab28b998e18396c06087b6d9b0ed Author: Marek Polacek <pola...@redhat.com> Date: Tue Mar 5 13:33:10 2024 -0500 c++: ICE with noexcept and local specialization [PR114114] Here we ICE because we call register_local_specialization while local_specializations is null, so local_specializations->put (); crashes on null this. It's null since maybe_instantiate_noexcept calls push_to_top_level which creates a new scope. Normally, I would have guessed that we need a new local_specialization_stack. But here we're dealing with an operand of a noexcept, which is an unevaluated operand, and those aren't registered in the hash map. maybe_instantiate_noexcept wasn't signalling that it's substituting an unevaluated operand though. PR c++/114114 gcc/cp/ChangeLog: * pt.cc (maybe_instantiate_noexcept): Save/restore cp_unevaluated_operand, c_inhibit_evaluation_warnings, and cp_noexcept_operand around the tsubst_expr call. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/noexcept84.C: New test. Diff: --- gcc/cp/pt.cc | 6 ++++++ gcc/testsuite/g++.dg/cpp0x/noexcept84.C | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index a6e6c804130..d73f6d93485 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -26879,10 +26879,16 @@ maybe_instantiate_noexcept (tree fn, tsubst_flags_t complain) if (orig_fn) ++processing_template_decl; + ++cp_unevaluated_operand; + ++c_inhibit_evaluation_warnings; + ++cp_noexcept_operand; /* Do deferred instantiation of the noexcept-specifier. */ noex = tsubst_expr (DEFERRED_NOEXCEPT_PATTERN (noex), DEFERRED_NOEXCEPT_ARGS (noex), tf_warning_or_error, fn); + --cp_unevaluated_operand; + --c_inhibit_evaluation_warnings; + --cp_noexcept_operand; /* Build up the noexcept-specification. */ spec = build_noexcept_spec (noex, tf_warning_or_error); diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept84.C b/gcc/testsuite/g++.dg/cpp0x/noexcept84.C new file mode 100644 index 00000000000..06f33264f77 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/noexcept84.C @@ -0,0 +1,32 @@ +// PR c++/114114 +// { dg-do compile { target c++11 } } + +template<bool B> +constexpr void +test () +{ + constexpr bool is_yes = B; + struct S { + constexpr S() noexcept(is_yes) { } + }; + S s; +} + +constexpr bool foo() { return true; } + +template<typename T> +constexpr void +test2 () +{ + constexpr T (*pfn)() = &foo; + struct S { + constexpr S() noexcept(pfn()) { } + }; + S s; +} + +int main() +{ + test<true>(); + test2<bool>(); +}