From: Jason Merrill <jason@redhat.com>
To: Andreas Krebbel <krebbel@linux.ibm.com>, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH 1/1] PR100281 C++: Fix SImode pointer handling
Date: Wed, 12 May 2021 10:43:10 -0400 [thread overview]
Message-ID: <5eec80c8-de07-a00c-aa2b-9991bfc567c4@redhat.com> (raw)
In-Reply-To: <20210430063232.12903-1-krebbel@linux.ibm.com>
On 4/30/21 2:32 AM, Andreas Krebbel via Gcc-patches 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.
>
> Bootstrapped and regression tested on x86_64 and s390x.
>
> 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 (cp_build_reference_type): Call
> cp_build_reference_type_for_mode with VOIDmode.
> (cp_build_reference_type_for_mode): Rename from
> cp_build_reference_type. Add MODE argument and invoke
> build_reference_type_for_mode if MODE isn't VOIDmode.
How about putting the VOIDmode special case in the generic
build_reference_type_for_mode instead of the C++ wrapper?
> (strip_typedefs): Use build_pointer_type_for_mode and
> cp_build_reference_type_for_mode for pointers and references.
>
> gcc/testsuite/ChangeLog:
>
> PR c++/100281
> * g++.target/s390/pr100281-1.C: New test.
> * g++.target/s390/pr100281-2.C: New test.
> ---
> gcc/cp/cvt.c | 2 +-
> gcc/cp/tree.c | 28 +++++++++++++++++-----
> gcc/testsuite/g++.target/s390/pr100281-1.C | 10 ++++++++
> gcc/testsuite/g++.target/s390/pr100281-2.C | 9 +++++++
> 4 files changed, 42 insertions(+), 7 deletions(-)
> create mode 100644 gcc/testsuite/g++.target/s390/pr100281-1.C
> create mode 100644 gcc/testsuite/g++.target/s390/pr100281-2.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..3817b499e46 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
> +
> +/* Return a reference type node of MODE referring to TO_TYPE. If MODE
> + is VOIDmode 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 == VOIDmode)
> + 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, VOIDmode, 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'.*" } */
> +}
>
next prev parent reply other threads:[~2021-05-12 14:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-30 6:32 Andreas Krebbel
2021-05-12 8:35 ` Andreas Krebbel
2021-05-12 14:43 ` Jason Merrill [this message]
2021-05-13 6:02 ` [PATCH 1/1 v2] " Andreas Krebbel
2021-05-17 8:48 ` Richard Biener
2021-05-17 18:01 ` Jason Merrill
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