[cfe-dev] clang::Qualifiers::TQ flags are not in sync with DeclSpec::TQ flags

[Vladimir Voskresensky via cfe-dev]

On 10.08.2017 02:31, John McCall wrote:
>> On Aug 9, 2017, at 4:51 PM, Vladimir Voskresensky via cfe-dev <cfe-dev at lists.llvm.org> wrote:
>> Ping,
>>
>> Could someone comment, please, if clang::Qualifiers::TQ intentionally reduces number of flags from 5 to 3?
> It is not intentional, no.  We do not represent _Atomic as an ordinary qualifier in the AST, so I think this might accidentally be okay there.  Offhand, I don't think we want to support either of those qualifiers as an array index type qualifier unless the C spec absolutely demands it.
Ok. Thanks for the information. I was mislead by
comment in clang::Qualifiers::TQ
// NOTE: These flags must be kept in sync with DeclSpec::TQ.
and the test where 5 bits value was written into 3 bits field.

Would be great if "note" can be clarified as well.

Thanks
Vladimir.

>
> John.
>
>> Thanks,
>> Vladimir.
>>
>> On 07.08.2017 16:06, Vladimir Voskresensky via cfe-dev wrote:
>>> Hello,
>>>
>>> clang::Qualifiers::TQ has 3 flags and CVRMask mask. Also it has the note:
>>> // NOTE: These flags must be kept in sync with DeclSpec::TQ.
>>>
>>> But
>>> DeclSpec::TQ has 5 flags (so  TQ_unaligned = 8, TQ_atomic = 16 are missed in clang::Qualifiers::TQ)
>>>
>>> This inconsistency can be found by debugging test llvm/tools/clang/test/Sema/MicrosoftExtensions.c on the last declaration:
>>> void test_unaligned2(int x[__unaligned 4]) {}
>>>
>>> Array type is created incorrectly here, because '__unaligned' is lost in the ArrayType constructor at line:
>>> ArrayTypeBits.IndexTypeQuals = tq;
>>> tq has value 8 (TQ_unaligned) while IndexTypeQuals is declared to use ":3" bits only, so IndexTypeQuals is zero after assign.
>>>
>>> Usually TQ fields are 5 bits (see i.e. DeclSpec::TypeQualifiers), so
>>> declaration Type::ArrayTypeBitfields::IndexTypeQuals must be fixed as well
>>>
>>> Hope it helps,
>>> Vladimir.
>>>
>>>
>>>
>>> _______________________________________________
>>> cfe-dev mailing list
>>> cfe-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev
>> _______________________________________________
>> cfe-dev mailing list
>> cfe-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev