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

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2019-01-16 15:48, Andreas Schwab wrote:
> On Jan 16 2019, Simon Marchi <simon.marchi@polymtl.ca> wrote:
> 
>> 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?
> 
> This has nothing to do with C vs. C++, both have the same wording:
> 
>     If the token defined is generated as a result of this replacement
>     process or use of the defined unary operator does not match one of
>     the two specified forms prior to macro replacement, the behavior is
>     undefined.
> 
> Andreas.

That's why I was confused, the purpose of Pavel's patch that was 
replaced by this one is C++-oriented:

https://sourceware.org/ml/gdb-patches/2019-01/msg00241.html

So in the end it looks like the issue is indeed not about C++, but about 
his usage of -Wextra (-Wexpansion-to-defined).

Simon