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.
Thanks,
Andrew
>
> Jason
>
