From 58b8c87b7fb281e35a6817cc91a292096fdc02dc Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Wed, 29 May 2024 04:49:37 -0400 Subject: c++: canonicity of fn types w/ instantiated eh specs [PR115223] When propagating structural equality in build_cp_fntype_variant, we should consider structural equality of the exception-less variant, not of the given type which might use structural equality only because it has a (complex) noexcept-spec that we're intending to replace, as in maybe_instantiate_noexcept which calls build_exception_variant using the deferred-noexcept function type. Otherwise we might pessimistically use structural equality for a function type with a simple instantiated noexcept-spec, leading to a LTO-triggered type verification failure if we later use that (structural-equality) type as the canonical version of some other variant. PR c++/115223 gcc/cp/ChangeLog: * tree.cc (build_cp_fntype_variant): Propagate structural equality of the exception-less variant. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/noexcept87.C: New test. Reviewed-by: Jason Merrill --- gcc/cp/tree.cc | 4 ++++ gcc/testsuite/g++.dg/cpp0x/noexcept87.C | 11 +++++++++++ 2 files changed, 15 insertions(+) create mode 100644 gcc/testsuite/g++.dg/cpp0x/noexcept87.C (limited to 'gcc') diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc index fe3f034..72dd46e 100644 --- a/gcc/cp/tree.cc +++ b/gcc/cp/tree.cc @@ -2796,6 +2796,10 @@ build_cp_fntype_variant (tree type, cp_ref_qualifier rqual, bool complex_eh_spec_p = (cr && cr != noexcept_true_spec && !UNPARSED_NOEXCEPT_SPEC_P (cr)); + if (!complex_eh_spec_p && TYPE_RAISES_EXCEPTIONS (type)) + /* We want to consider structural equality of the exception-less + variant since we'll be replacing the exception specification. */ + type = build_cp_fntype_variant (type, rqual, /*raises=*/NULL_TREE, late); if (TYPE_STRUCTURAL_EQUALITY_P (type) || complex_eh_spec_p) /* Propagate structural equality. And always use structural equality for function types with a complex noexcept-spec since their identity diff --git a/gcc/testsuite/g++.dg/cpp0x/noexcept87.C b/gcc/testsuite/g++.dg/cpp0x/noexcept87.C new file mode 100644 index 0000000..339569d --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/noexcept87.C @@ -0,0 +1,11 @@ +// PR c++/115223 +// { dg-do compile { target c++11 } } +// { dg-additional-options -flto } + +template +void f() noexcept(bool(T() || true)); + +void g() { f(); } + +using type = void; +type callDestructorIfNecessary() noexcept {} -- cgit v1.1