Re: [PATCH] Do not expand macros to 'defined'

[Pavel Kryukov <kryukov@frtk.ru>]

> which supposedly can handle this fine

Right, but not with '-Wall -Wextra -Werror' flags.
These pedantic options help us (a little) keeping C++ project portable
between compilers, although we do not intent to have this property on GDB integration.

--
Pavel

> 16 янв. 2019 г., в 23:02, Simon Marchi <simon.marchi@polymtl.ca> написал(а):
> 
>> On 2019-01-16 01:34, Павел Крюков wrote:
>> Expanding a macro which contains 'defined' PP keyword is UB.
>> sim/common/Changelog:
>> 2019-01-16  Pavel I. Kryukov  <kryukov@frtk.ru>
>>        * sim-arange.c: eliminate DEFINE_NON_INLINE_P
>> ---
>> sim/common/sim-arange.c | 11 +++--------
>> 1 file changed, 3 insertions(+), 8 deletions(-)
>> diff --git a/sim/common/sim-arange.c b/sim/common/sim-arange.c
>> index 6373b742ce8..b3488ab564a 100644
>> --- a/sim/common/sim-arange.c
>> +++ b/sim/common/sim-arange.c
>> @@ -32,10 +32,7 @@ along with this program.  If not, see
>> <http://www.gnu.org/licenses/>.  */
>> #include <string.h>
>> #endif
>> -#define DEFINE_INLINE_P (! defined (SIM_ARANGE_C_INCLUDED))
>> -#define DEFINE_NON_INLINE_P defined (SIM_ARANGE_C_INCLUDED)
>> -
>> -#if DEFINE_NON_INLINE_P
>> +#ifdef SIM_ARANGE_C_INCLUDED
>> /* Insert a range.  */
>> @@ -280,9 +277,7 @@ sim_addr_range_delete (ADDR_RANGE *ar,
>> address_word start, address_word end)
>>   build_search_tree (ar);
>> }
>> -#endif /* DEFINE_NON_INLINE_P */
>> -
>> -#if DEFINE_INLINE_P
>> +#else /* SIM_ARANGE_C_INCLUDED */
>> SIM_ARANGE_INLINE int
>> sim_addr_range_hit_p (ADDR_RANGE *ar, address_word addr)
>> @@ -301,4 +296,4 @@ sim_addr_range_hit_p (ADDR_RANGE *ar, address_word addr)
>>   return 0;
>> }
>> -#endif /* DEFINE_INLINE_P */
>> +#endif /* SIM_ARANGE_C_INCLUDED */
> 
> The patch LGTM, I agree these macros are not really needed.  But I am confused, does this actually fix your c++ build?  You mentioned you were using g++ (and therefore cpp), which supposedly can handle this fine:
> 
> https://gcc.gnu.org/onlinedocs/cpp/Defined.html
> 
> If so, what did the error look like?
> 
> Simon