Re: [V7][PATCH 1/2] Handle component_ref to a structre/union field including flexible array member [PR101832]

[Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>]

On 24 May 2023 16:09:21 CEST, Qing Zhao <qing.zhao@oracle.com> wrote:
>Bernhard,
>
>Thanks a lot for your comments.
>
>> On May 19, 2023, at 7:11 PM, Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> wrote:
>> 
>> On Fri, 19 May 2023 20:49:47 +0000
>> Qing Zhao via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
>> 
>>> GCC extension accepts the case when a struct with a flexible array member
>>> is embedded into another struct or union (possibly recursively).
>> 
>> Do you mean TYPE_TRAILING_FLEXARRAY()?
>
>The following might be more accurate description:
>
>GCC extension accepts the case when a struct with a flexible array member
> is embedded into another struct or union (possibly recursively) as the last field.
>
>
>
>> 
>>> diff --git a/gcc/tree.h b/gcc/tree.h
>>> index 0b72663e6a1..237644e788e 100644
>>> --- a/gcc/tree.h
>>> +++ b/gcc/tree.h
>>> @@ -786,7 +786,12 @@ extern void omp_clause_range_check_failed (const_tree, const char *, int,
>>>    (...) prototype, where arguments can be accessed with va_start and
>>>    va_arg), as opposed to an unprototyped function.  */
>>> #define TYPE_NO_NAMED_ARGS_STDARG_P(NODE) \
>>> -  (TYPE_CHECK (NODE)->type_common.no_named_args_stdarg_p)
>>> +  (FUNC_OR_METHOD_CHECK (NODE)->type_common.no_named_args_stdarg_p)
>>> +
>>> +/* True if this RECORD_TYPE or UNION_TYPE includes a flexible array member
>>> +   at the last field recursively.  */
>>> +#define TYPE_INCLUDE_FLEXARRAY(NODE) \
>>> +  (RECORD_OR_UNION_CHECK (NODE)->type_common.no_named_args_stdarg_p)
>> 
>> Until i read the description above i read TYPE_INCLUDE_FLEXARRAY as an
>> option to include or not include something. The description hints more
>> at TYPE_INCLUDES_FLEXARRAY (with an S) to be a type which has at least
>> one member which has a trailing flexible array or which itself has a
>> trailing flexible array.
>
>Yes, TYPE_INCLUDES_FLEXARRAY (maybe with a S is a better name) means the structure/union TYPE includes a flexible array member or includes a struct with a flexible array member as the last field.
>

So ANY_TRAILING_FLEXARRAY or TYPE_CONTAINS_FLEXARRAY, TYPE_INCLUDES_FLEXARRAY or something like that would be more clear, i don't know.
I'd probably use the first, but that's enough bike shedding for me now. Let's see what others think.

thanks,

>Hope this is clear.
>thanks.
>
>Qing
>> 
>>> 
>>> /* In an IDENTIFIER_NODE, this means that assemble_name was called with
>>>    this string as an argument.  */
>> 
>