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

[Qing Zhao <qing.zhao@oracle.com>]

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.

Hope this is clear.
thanks.

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