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?
Yes. build_pointer_type_for_mode carries some additional logic compared to just
build_pointer_type
and I wanted to avoid impacting other targets that way.
>
>> 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.
Ok. I'll have a look.
Andreas
>
>> 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
>>
