| Message ID | 20240525231828.1043776-1-ppalka@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: canonicity of fn types w/ instantiated eh specs [PR115223] | expand |
On 5/25/24 19:18, Patrick Palka wrote: > Bootstrap and regtest on x86_64-pc-linux-gnu in progress, > does this look OK for trunk if successful? OK. > -- >8 -- > > 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 of > the (complex) noexcept-spec we're intending to replace, as in > maybe_instantiate_noexcept which calls build_exception_variant using > the function type with a deferred noexcept-spec. Otherwise we might > pessimisticly use structural equality for a function type with a simple > instantiated noexcept-spec, leading to a failed LTO-specific sanity > check 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. > --- > 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 > > diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc > index 4d87661b4ad..f810b8cd777 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 00000000000..60b1497472b > --- /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<class T> > +void f() noexcept(bool(T() || true)); > + > +void g(int n) { f<int>(); } > + > +using type = void; > +type callDestructorIfNecessary() noexcept {}
diff --git a/gcc/cp/tree.cc b/gcc/cp/tree.cc index 4d87661b4ad..f810b8cd777 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 00000000000..60b1497472b --- /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<class T> +void f() noexcept(bool(T() || true)); + +void g(int n) { f<int>(); } + +using type = void; +type callDestructorIfNecessary() noexcept {}