On Wed, Apr 28, 2021 at 1:52 PM Andreas Krebbel <kreb...@linux.ibm.com> wrote:
>
> On 4/28/21 10:12 AM, Richard Biener wrote:
> > On Wed, Apr 28, 2021 at 8:54 AM Andreas Krebbel via Gcc-patches
> > <gcc-patches@gcc.gnu.org> wrote:
> >>
> >> The problem appears to be triggered by two locations in the front-end
> >> where non-POINTER_SIZE pointers aren't handled right now.
> >>
> >> 1. An assertion in strip_typedefs is triggered because the alignment
> >> of the types don't match. This in turn is caused by creating the new
> >> type with build_pointer_type instead of taking the type of the
> >> original pointer into account.
> >>
> >> 2. An assertion in cp_convert_to_pointer is triggered which expects
> >> the target type to always have POINTER_SIZE.
> >>
> >> Ok for mainline?
> >>
> >> gcc/cp/ChangeLog:
> >>
> >> PR c++/100281
> >> * cvt.c (cp_convert_to_pointer): Use the size of the target
> >> pointer type.
> >> * tree.c (strip_typedefs): Use build_pointer_type_for_mode for
> >> non-POINTER_SIZE pointers.
> >>
> >> gcc/testsuite/ChangeLog:
> >>
> >> PR c++/100281
> >> * g++.target/s390/pr100281.C: New test.
> >> ---
> >> gcc/cp/cvt.c | 2 +-
> >> gcc/cp/tree.c | 5 ++++-
> >> gcc/testsuite/g++.target/s390/pr100281.C | 10 ++++++++++
> >> 3 files changed, 15 insertions(+), 2 deletions(-)
> >> create mode 100644 gcc/testsuite/g++.target/s390/pr100281.C
> >>
> >> diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c
> >> index f1687e804d1..7fa6e8df52b 100644
> >> --- a/gcc/cp/cvt.c
> >> +++ b/gcc/cp/cvt.c
> >> @@ -232,7 +232,7 @@ cp_convert_to_pointer (tree type, tree expr, bool
> >> dofold,
> >> {
> >> if (TYPE_PRECISION (intype) == POINTER_SIZE)
> >> return build1 (CONVERT_EXPR, type, expr);
> >> - expr = cp_convert (c_common_type_for_size (POINTER_SIZE, 0), expr,
> >> + expr = cp_convert (c_common_type_for_size (TYPE_PRECISION (type),
> >> 0), expr,
> >> complain);
> >> /* Modes may be different but sizes should be the same. There
> >> is supposed to be some integral type that is the same width
> >> diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
> >> index a8bfd5fc053..6f6b732c9c9 100644
> >> --- a/gcc/cp/tree.c
> >> +++ b/gcc/cp/tree.c
> >> @@ -1556,7 +1556,10 @@ strip_typedefs (tree t, bool *remove_attributes,
> >> unsigned int flags)
> >> {
> >> case POINTER_TYPE:
> >> type = strip_typedefs (TREE_TYPE (t), remove_attributes, flags);
> >> - result = build_pointer_type (type);
> >> + if (TYPE_PRECISION (t) == POINTER_SIZE)
> >> + result = build_pointer_type (type);
> >> + else
> >> + result = build_pointer_type_for_mode (type, TYPE_MODE (t), false);
> >
> > I wonder under which circumstances re-using the original mode will fail? In
> > particular I do not like the TYPE_PRECISION check. Supposedly you
> > were thinking of playing safe?
> >
> >> break;
> >> case REFERENCE_TYPE:
> >> type = strip_typedefs (TREE_TYPE (t), remove_attributes, flags);
> >
> > There's code below with exactly the same issue for reference types which
> > would need adjustments to cp_build_reference_type.
> >
> >> diff --git a/gcc/testsuite/g++.target/s390/pr100281.C
> >> b/gcc/testsuite/g++.target/s390/pr100281.C
> >> new file mode 100644
> >> index 00000000000..f45798c3879
> >> --- /dev/null
> >> +++ b/gcc/testsuite/g++.target/s390/pr100281.C
> >> @@ -0,0 +1,10 @@
> >> +// PR C++/100281
> >> +// { dg-do compile }
> >> +
> >> +typedef void * __attribute__((mode (SI))) __ptr32_t;
> >> +
> >> +void foo(){
> >> + unsigned int b = 100;
> >> + __ptr32_t a;
> >> + a = b; /* { dg-error "invalid conversion from 'unsigned int' to
> >> '__ptr32_t'.*" } */
> >> +}
> >> --
> >> 2.30.2
> >>
>
> Like so?
Sth like that - the MAX_MACHINE_MODE thing is a bit ugly
(maybe use VOIDmode?). Of course should be reviewed by a C++ maintainer.
Richard.
> diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c
> index f1687e804d1..7fa6e8df52b 100644
> --- a/gcc/cp/cvt.c
> +++ b/gcc/cp/cvt.c
> @@ -232,7 +232,7 @@ cp_convert_to_pointer (tree type, tree expr, bool dofold,
> {
> if (TYPE_PRECISION (intype) == POINTER_SIZE)
> return build1 (CONVERT_EXPR, type, expr);
> - expr = cp_convert (c_common_type_for_size (POINTER_SIZE, 0), expr,
> + expr = cp_convert (c_common_type_for_size (TYPE_PRECISION (type), 0),
> expr,
> complain);
> /* Modes may be different but sizes should be the same. There
> is supposed to be some integral type that is the same width
> diff --git a/gcc/cp/tree.c b/gcc/cp/tree.c
> index a8bfd5fc053..fe5c414c8d9 100644
> --- a/gcc/cp/tree.c
> +++ b/gcc/cp/tree.c
> @@ -1201,12 +1201,14 @@ vla_type_p (tree t)
> return false;
> }
>
> -/* Return a reference type node referring to TO_TYPE. If RVAL is
> - true, return an rvalue reference type, otherwise return an lvalue
> - reference type. If a type node exists, reuse it, otherwise create
> - a new one. */
> +
> +/* Return a reference type node of MODE referring to TO_TYPE. If MODE
> + is MAX_MACHINE_MODE the standard pointer mode will be picked. If
> + RVAL is true, return an rvalue reference type, otherwise return an
> + lvalue reference type. If a type node exists, reuse it, otherwise
> + create a new one. */
> tree
> -cp_build_reference_type (tree to_type, bool rval)
> +cp_build_reference_type_for_mode (tree to_type, machine_mode mode, bool rval)
> {
> tree lvalue_ref, t;
>
> @@ -1219,7 +1221,11 @@ cp_build_reference_type (tree to_type, bool rval)
> to_type = TREE_TYPE (to_type);
> }
>
> - lvalue_ref = build_reference_type (to_type);
> + if (mode == MAX_MACHINE_MODE)
> + lvalue_ref = build_reference_type (to_type);
> + else
> + lvalue_ref = build_reference_type_for_mode (to_type, mode, false);
> +
> if (!rval)
> return lvalue_ref;
>
> @@ -1245,7 +1251,7 @@ cp_build_reference_type (tree to_type, bool rval)
> SET_TYPE_STRUCTURAL_EQUALITY (t);
> else if (TYPE_CANONICAL (to_type) != to_type)
> TYPE_CANONICAL (t)
> - = cp_build_reference_type (TYPE_CANONICAL (to_type), rval);
> + = cp_build_reference_type_for_mode (TYPE_CANONICAL (to_type), mode,
> rval);
> else
> TYPE_CANONICAL (t) = t;
>
> @@ -1255,6 +1261,16 @@ cp_build_reference_type (tree to_type, bool rval)
>
> }
>
> +/* Return a reference type node referring to TO_TYPE. If RVAL is
> + true, return an rvalue reference type, otherwise return an lvalue
> + reference type. If a type node exists, reuse it, otherwise create
> + a new one. */
> +tree
> +cp_build_reference_type (tree to_type, bool rval)
> +{
> + return cp_build_reference_type_for_mode (to_type, MAX_MACHINE_MODE, rval);
> +}
> +
> /* Returns EXPR cast to rvalue reference type, like std::move. */
>
> tree
> @@ -1556,11 +1572,11 @@ strip_typedefs (tree t, bool *remove_attributes,
> unsigned int flags)
> {
> case POINTER_TYPE:
> type = strip_typedefs (TREE_TYPE (t), remove_attributes, flags);
> - result = build_pointer_type (type);
> + result = build_pointer_type_for_mode (type, TYPE_MODE (t), false);
> break;
> case REFERENCE_TYPE:
> type = strip_typedefs (TREE_TYPE (t), remove_attributes, flags);
> - result = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
> + result = cp_build_reference_type_for_mode (type, TYPE_MODE (t),
> TYPE_REF_IS_RVALUE (t));
> break;
> case OFFSET_TYPE:
> t0 = strip_typedefs (TYPE_OFFSET_BASETYPE (t), remove_attributes,
> flags);
> diff --git a/gcc/testsuite/g++.target/s390/pr100281-1.C
> b/gcc/testsuite/g++.target/s390/pr100281-1.C
> new file mode 100644
> index 00000000000..b82e27b64e9
> --- /dev/null
> +++ b/gcc/testsuite/g++.target/s390/pr100281-1.C
> @@ -0,0 +1,10 @@
> +// PR C++/100281
> +// { dg-do compile }
> +
> +typedef void * __attribute__((mode (SI))) __ptr32_t;
> +
> +void foo () {
> + unsigned int b = 100;
> + __ptr32_t a;
> + a = b; /* { dg-error "invalid conversion from 'unsigned int' to
> '__ptr32_t'.*" } */
> +}
> diff --git a/gcc/testsuite/g++.target/s390/pr100281-2.C
> b/gcc/testsuite/g++.target/s390/pr100281-2.C
> new file mode 100644
> index 00000000000..58552becd7c
> --- /dev/null
> +++ b/gcc/testsuite/g++.target/s390/pr100281-2.C
> @@ -0,0 +1,9 @@
> +// PR C++/100281
> +// { dg-do compile }
> +
> +typedef int & __attribute__((mode (SI))) __ref32_t;
> +
> +void foo () {
> + unsigned int b = 100;
> + __ref32_t a = b; /* { dg-error "cannot bind non-const lvalue reference of
> type '__ref32_t'.*" } */
> +}
> --
> 2.30.2
>
>
