Re: Request for compiler option to disable multiple declarations in a single statement

[David Brown <david at westcontrol dot com>]

On 19/04/18 11:27, Manish Jain wrote:
> 
> On 04/19/18 14:46, David Brown wrote:
>> Certainly it is heavily used in existing code - making an option
>> to disable it would be impractical.
> 
> Thanks for replying, Mr. Brown.
> 
> What I meant was if an option could be provided, existing code could 
> compile without the option, and fresh code to compile with the switch 
> enabled (as per user discretion, of course - no compulsion either way 
> anywhere).

If it were an option for what code is acceptable, rather than a warning,
you would have trouble with header files that had multiple declarations
- it would quickly become unusable.  A warning is much friendlier in
such contexts.  (In particular, warnings like that are by default
disabled for system headers.)

> 
> If the option garners wide recognition / usage, over a period of time 
> the standard pointer declaration could be fixed to everyone's happiness:
> 
> int* p; // which really is what it should be in all propriety

That is a /highly/ subjective view.  I too prefer one declaration per
line in most cases, but I am not the only C programmer around - you
can't consider your personal opinion to be the only right one.

> 
> The current declaration style really sickens me, particularly when 
> trying to explain C pointers to others.
> 

There is nothing to stop you using the style you want in the code you
write yourself.  This warning would simply be a way to mark breaking a
code style guiderule.

It may be better implemented in a plugin, rather than in gcc itself.