On Mon, Jun 24, 2024 at 10:00:40PM -0700, Andrew Pinski wrote:
> The problem here is even though we pass std namespace to lookup_template_class
> as the context, it will look at the current scope for the name too.
> The fix is to lookup the qualified name first and then use that
> for lookup_template_class.
> This is how std::initializer_list is handled in listify.
>
> Note g++.dg/cpp1z/decomp22.C testcase now fails correctly
> with an error, that tuple_size is not in the std namespace.
> I copied a fixed up testcase into g++.dg/cpp1z/decomp62.C.
>
> Bootstrapped and tested on x86_64-linux-gnu with no regressions.
>
> PR c++/115605
>
> gcc/cp/ChangeLog:
>
> * decl.cc (get_tuple_size): Call lookup_qualified_name
> before calling lookup_template_class.
> (get_tuple_element_type): Likewise.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/cpp1z/decomp22.C: Expect an error
Missing .
> * g++.dg/cpp1z/decomp61.C: New test.
> * g++.dg/cpp1z/decomp62.C: Copied from decomp22.C
> and wrap tuple_size/tuple_element inside std namespace.
>
> Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
> ---
> gcc/cp/decl.cc | 16 +++++---
> gcc/testsuite/g++.dg/cpp1z/decomp22.C | 2 +-
> gcc/testsuite/g++.dg/cpp1z/decomp61.C | 53 +++++++++++++++++++++++++++
> gcc/testsuite/g++.dg/cpp1z/decomp62.C | 23 ++++++++++++
> 4 files changed, 88 insertions(+), 6 deletions(-)
> create mode 100644 gcc/testsuite/g++.dg/cpp1z/decomp61.C
> create mode 100644 gcc/testsuite/g++.dg/cpp1z/decomp62.C
>
> diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
> index 03deb1493a4..81dde4d51a3 100644
> --- a/gcc/cp/decl.cc
> +++ b/gcc/cp/decl.cc
> @@ -9195,10 +9195,13 @@ get_tuple_size (tree type)
> {
> tree args = make_tree_vec (1);
> TREE_VEC_ELT (args, 0) = type;
> - tree inst = lookup_template_class (tuple_size_identifier, args,
> + tree std_tuple_size = lookup_qualified_name (std_node,
> tuple_size_identifier);
> + if (std_tuple_size == error_mark_node)
> + return NULL_TREE;
> + tree inst = lookup_template_class (std_tuple_size, args,
> /*in_decl*/NULL_TREE,
> - /*context*/std_node,
> - tf_none);
> + /*context*/NULL_TREE,
> + tf_warning_or_error);
> inst = complete_type (inst);
> if (inst == error_mark_node
> || !COMPLETE_TYPE_P (inst)
> @@ -9224,9 +9227,12 @@ get_tuple_element_type (tree type, unsigned i)
> tree args = make_tree_vec (2);
> TREE_VEC_ELT (args, 0) = build_int_cst (integer_type_node, i);
> TREE_VEC_ELT (args, 1) = type;
> - tree inst = lookup_template_class (tuple_element_identifier, args,
> + tree std_tuple_elem = lookup_qualified_name (std_node,
> tuple_element_identifier);
This line is too long.
> + if (std_tuple_elem == error_mark_node)
> + return NULL_TREE;
> + tree inst = lookup_template_class (std_tuple_elem, args,
> /*in_decl*/NULL_TREE,
> - /*context*/std_node,
> + /*context*/NULL_TREE,
> tf_warning_or_error);
> return make_typename_type (inst, type_identifier,
> none_type, tf_warning_or_error);
> diff --git a/gcc/testsuite/g++.dg/cpp1z/decomp22.C
> b/gcc/testsuite/g++.dg/cpp1z/decomp22.C
> index 9e6b8df486a..4131486e292 100644
> --- a/gcc/testsuite/g++.dg/cpp1z/decomp22.C
> +++ b/gcc/testsuite/g++.dg/cpp1z/decomp22.C
> @@ -17,5 +17,5 @@ int
> foo (C<int> t)
> {
> auto[x0] = t; // { dg-warning "structured bindings only available
> with" "" { target c++14_down } }
> - return x0;
> + return x0; /* { dg-error "cannot convert" } */
> }
> diff --git a/gcc/testsuite/g++.dg/cpp1z/decomp61.C
> b/gcc/testsuite/g++.dg/cpp1z/decomp61.C
> new file mode 100644
> index 00000000000..874844b2c61
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/cpp1z/decomp61.C
> @@ -0,0 +1,53 @@
> +// PR c++/115605
> +// { dg-do compile { target c++17 } }
> +// { dg-options "" }
(I don't think you need the empty dg-options here.)
The patch looks good to me otherwise, thanks.
Marek
