On Wed, 12 Jun 2024, Jason Merrill wrote:
> Tested x86_64-pc-linux-gnu, applying to trunk.
>
> -- 8< --
>
> exception_ptr.h contains
>
> namespace __exception_ptr
> {
> class exception_ptr;
> }
> using __exception_ptr::exception_ptr;
>
> so when module std tries to 'export using std::exception_ptr', it names
> another using-directive rather than the class directly, so __exception_ptr
> is never explicitly opened in module purview.
FWIW PR100134 ICEd in the same way, and r13-3236-g9736a42e1fb8df
narrowly fixed this by setting DECL_MODULE_PURVIEW_P on the enclosing
namespace around the time we set the flag on the namespace-scope entity in
question. I wonder if it'd be preferable to do something similar here,
e.g. set DECL_MODULE_PURVIEW_P on the enclosing namespace in
do_nonmember_using_decl?
>
> gcc/cp/ChangeLog:
>
> * module.cc (depset::hash::add_binding_entity): Set
> DECL_MODULE_PURVIEW_P instead of asserting.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/modules/using-20_a.C: New test.
> ---
> gcc/cp/module.cc | 7 +++++--
> gcc/testsuite/g++.dg/modules/using-20_a.C | 14 ++++++++++++++
> 2 files changed, 19 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/g++.dg/modules/using-20_a.C
>
> diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
> index 21fc85150c9..72e876cec18 100644
> --- a/gcc/cp/module.cc
> +++ b/gcc/cp/module.cc
> @@ -13253,8 +13253,11 @@ depset::hash::add_binding_entity (tree decl,
> WMB_Flags flags, void *data_)
> data->met_namespace = true;
> if (data->hash->add_namespace_entities (decl, data->partitions))
> {
> - /* It contains an exported thing, so it is exported. */
> - gcc_checking_assert (DECL_MODULE_PURVIEW_P (decl));
> + /* It contains an exported thing, so it is exported.
> + We used to assert DECL_MODULE_PURVIEW_P, but that fails for a
> + namespace like std::__exception_ptr which is never opened in
> + module purview; the exporting using finds another using. */
> + DECL_MODULE_PURVIEW_P (decl) = true;
> DECL_MODULE_EXPORT_P (decl) = true;
> }
>
> diff --git a/gcc/testsuite/g++.dg/modules/using-20_a.C
> b/gcc/testsuite/g++.dg/modules/using-20_a.C
> new file mode 100644
> index 00000000000..bb3bb6160f8
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/modules/using-20_a.C
> @@ -0,0 +1,14 @@
> +// { dg-additional-options "-fmodules-ts -fdump-lang-module
> -Wno-global-module" }
> +// { dg-final { scan-lang-dump {Writing definition '::foo::bar::baz'} module
> } }
> +
> +module;
> +namespace foo {
> + namespace bar {
> + struct baz { };
> + }
> + using bar::baz;
> +}
> +export module foo;
> +namespace foo {
> + export using foo::baz;
> +}
>
> base-commit: 7bf072e87a03c9eaff9b7a1ac182537b70f0ba8e
> --
> 2.44.0
>
>
