Re: [RFA] (cli/cli-cmds.c) ARI fix: Avoid assignment inside if statement

[Joel Brobecker <brobecker@adacore.com>]

> > Since when is that bad C, so much so that we would need to enforce it?
> 
> Interesting...  I remember when I started hacking GDB, I was strongly
> discouraged to do assignments inside `if' checkings.  I don't remember
> who told me that, but the reason was something related to the Coding
> Standards (I don't have any references either).  Anyway, since that
> moment I stopped doing this...

It is in the GNU Coding Standards:
http://www.gnu.org/prep/standards/standards.html#Syntactic-Conventions

In particular:

    | Try to avoid assignments inside if-conditions (assignments inside
    | while-conditions are ok). For example, don’t write this:
    |
    | if ((foo = (char *) malloc (sizeof *foo)) == 0)
    |   fatal ("virtual memory exhausted");
    | instead, write this:
    |
    | foo = (char *) malloc (sizeof *foo);
    | if (foo == 0)
    |   fatal ("virtual memory exhausted");

FWIW, I mostly agree with this suggestion, particulary in the
examples above. I do remember seeing some examples where it was
more practical if we could have assignments inside conditions
(in an "if ... else if ..." situation), but even then, I find
that it makes it harder to notice the assignment.

In the examples that Pierre chose to fix, it seems obvious to me
(this is a judgement call, so potentially subject to disagreement)
that there was no need to have the assignment inside the condition,
and that the patched code is easier to grasp. I think it is
a clear improvement.

> FWIW, I agree that it is not bad C, and totally valid

I think that the point is not that this is bad C, or not
valid/portable. I think that the point is that it is judged
to be a poor practice.

-- 
Joel