On Tue, Apr 30, 2024 at 9:13 PM Jason Merrill <ja...@redhat.com> wrote:
>
> On 4/30/24 12:04, Andrew Pinski wrote:
> > On Tue, Apr 30, 2024 at 11:54 AM Jason Merrill <ja...@redhat.com> wrote:
> >>
> >> On 2/20/24 19:06, Andrew Pinski wrote:
> >>> After r7-987-gf17a223de829cb, the access for the elements of a vector
> >>> type would lose the qualifiers.
> >>> So if we had `constvector[0]`, the type of the element of the array would
> >>> not have const on it.
> >>> This was due to a missing build_qualified_type for the inner type of the
> >>> vector when building the array type.
> >>> We need to add back the call to build_qualified_type and now the access
> >>> has the correct qualifiers. So the
> >>> overloads and even if it is a lvalue or rvalue is correctly done.
> >>>
> >>> Note we correctly now reject the testcase gcc.dg/pr83415.c which was
> >>> incorrectly accepted after r7-987-gf17a223de829cb.
> >>>
> >>> Built and tested for aarch64-linux-gnu.
> >>>
> >>> PR c++/89224
> >>>
> >>> gcc/c-family/ChangeLog:
> >>>
> >>> * c-common.cc (convert_vector_to_array_for_subscript): Call
> >>> build_qualified_type
> >>> for the inner type.
> >>>
> >>> gcc/cp/ChangeLog:
> >>>
> >>> * constexpr.cc (cxx_eval_array_reference): Compare main variants
> >>> for the vector/array types instead of the types directly.
> >>>
> >>> gcc/testsuite/ChangeLog:
> >>>
> >>> * g++.dg/torture/vector-subaccess-1.C: New test.
> >>> * gcc.dg/pr83415.c: Change warning to error.
> >>>
> >>> Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
> >>> ---
> >>> gcc/c-family/c-common.cc | 7 +++++-
> >>> gcc/cp/constexpr.cc | 3 ++-
> >>> .../g++.dg/torture/vector-subaccess-1.C | 23 +++++++++++++++++++
> >>> gcc/testsuite/gcc.dg/pr83415.c | 2 +-
> >>> 4 files changed, 32 insertions(+), 3 deletions(-)
> >>> create mode 100644 gcc/testsuite/g++.dg/torture/vector-subaccess-1.C
> >>>
> >>> diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc
> >>> index e15eff698df..884dd9043f9 100644
> >>> --- a/gcc/c-family/c-common.cc
> >>> +++ b/gcc/c-family/c-common.cc
> >>> @@ -8936,6 +8936,7 @@ convert_vector_to_array_for_subscript (location_t
> >>> loc,
> >>> if (gnu_vector_type_p (TREE_TYPE (*vecp)))
> >>> {
> >>> tree type = TREE_TYPE (*vecp);
> >>> + tree newitype;
> >>>
> >>> ret = !lvalue_p (*vecp);
> >>>
> >>> @@ -8950,8 +8951,12 @@ convert_vector_to_array_for_subscript (location_t
> >>> loc,
> >>> for function parameters. */
> >>> c_common_mark_addressable_vec (*vecp);
> >>>
> >>> + /* Make sure qualifiers are copied from the vector type to the new
> >>> element
> >>> + of the array type. */
> >>> + newitype = build_qualified_type (TREE_TYPE (type), TYPE_QUALS
> >>> (type));
> >>> +
> >>> *vecp = build1 (VIEW_CONVERT_EXPR,
> >>> - build_array_type_nelts (TREE_TYPE (type),
> >>> + build_array_type_nelts (newitype,
> >>> TYPE_VECTOR_SUBPARTS (type)),
> >>> *vecp);
> >>> }
> >>> diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
> >>> index fa346fe01c9..1fe91d16e8e 100644
> >>> --- a/gcc/cp/constexpr.cc
> >>> +++ b/gcc/cp/constexpr.cc
> >>> @@ -4421,7 +4421,8 @@ cxx_eval_array_reference (const constexpr_ctx *ctx,
> >>> tree t,
> >>> if (!lval
> >>> && TREE_CODE (ary) == VIEW_CONVERT_EXPR
> >>> && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0)))
> >>> - && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0))))
> >>> + && TYPE_MAIN_VARIANT (TREE_TYPE (t))
> >>> + == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary,
> >>> 0)))))
> >>
> >> Please add parens around the == expression so the formatting is stable.
> > ok, I will make that change.
> >
> >>
> >> With that change, OK for trunk and release branches.
> >
> > For the GCC 14 branch, should I wait until after the release due to
> > RC1 going out today and I am not sure this counts as a show stopper
> > issue.
>
> That's not my call ("all changes to the branch require a RM approval
> now") but I think it can wait for 14.2.
Yes, this should wait.
Richard.
> Jason
>
