On 4/28/21 10:22 AM, Andreas Krebbel via Gcc-patches 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
>> <[email protected]> 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.
build_pointer_type just calls build_pointer_type_for_mode. I'll drop the check
then and re-test.
>
>>
>>> 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
>>>
>
