Re: [[GCC13][Patch][V3] 1/2] Add a new option -fstrict-flex-array[=n] and new attribute strict_flex_array

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

Hi, Joseph,

Thanks a lot for your comment.

> On Aug 30, 2022, at 6:53 PM, Joseph Myers <joseph@codesourcery.com> wrote:
> 
> On Tue, 30 Aug 2022, Qing Zhao via Gcc-patches wrote:
> 
>> Hi, Joseph and Nathan,
>> 
>> Could you please review the C and C++ FE parts of the patch?
>> 
>> https://gcc.gnu.org/pipermail/gcc-patches/2022-August/599901.html
> 
> I think some work is still needed on the diagnostic wording.
> 
>> +  "%qE attribute may not be specified for a non array field",
> 
> "non-array" not "non array".

Okay.

> 
>> +       "not supported with a ISO C before C99", name);
> 
> "a ISO C" is not proper usage.  I think something like "by ISO C before 
> C99" would be better.  Likewise "a ISO C++".
> 
> "!flag_isoc99" is more usual than "flag_isoc99 == 0".

Okay.

> 
>> +       "not supported with a GNU extension GNU89", name);
> 
> "a GNU extension" suggests a particular language feature, but I think 
> you're actually referring here to a whole language version rather than an 
> individual feature.

Is “not supported by GNU extension GNU89” better?

> 
> In any case, -std=gnu89 supports flexible array members.

Yes, but only [0],[1] are supported as flexible array members.  The C99 flexible array member [] is not supported by GNU89, right?

Then, -fstrict-flex-arrays=3 is not supported by -std=gnu89.


>  So I'd expect 
> them to have exactly the same semantics as in C99, so disallowing a 
> particular feature for gnu89 here seems suspect.
> 
> In the manual, any literal code should be enclosed in @code{} or @samp{}.  
> That replaces the use of ASCII quotes "" that you currently have in the 
> documentation (that should never be used outside of @code, @samp and 
> similar).

Okay. Will update those places.
> 
>> +When -std=gnu89 is specified or C++ with GNU extension, only zero-length array
> 
> And @option{} should be used around "-std=gnu89" here (except as noted 
> above, I think it's suspect to disallow parts of this feature for gnu89).

Okay. Will update.
> 
>> +language. FOR ISO C before C99 and ISO C++, no language support for the flexible
> 
> "FOR" should be "For".

Okay.

thanks.

Qing
> 
> -- 
> Joseph S. Myers
> joseph@codesourcery.com