Re: Coding Style for local variables

[Stephen Hemminger <stephen@networkplumber.org>]

On Thu, 20 Jun 2024 11:02:21 +0200
Morten Brørup <mb@smartsharesystems.com> wrote:

> > From: Konstantin Ananyev [mailto:konstantin.ananyev@huawei.com]
> >   
> > > > From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > > >
> > > > 10/06/2024 18:31, Konstantin Ananyev:  
> > > > > Morten said:  
> > > > > > The coding style guide says:
> > > > > >
> > > > > > "Variables should be declared at the start of a block of code rather  
> > than  
> > > > in the middle. The exception to this is when the variable is  
> > > > > > const in which case the declaration must be at the point of first  
> > > > use/assignment. Declaring variable inside a for loop is OK."  
> > > > > >
> > > > > > Since DPDK switched to C11, variables can be declared where they are  
> > used,  
> > > > which reduces the risk of using effectively uninitialized  
> > > > > > variables. "Effectively uninitialized" means initialized to 0 or NULL  
> > > > where declared, to silence any compiler warnings about the use of  
> > > > > > uninitialized variables.
> > > > > >
> > > > > > Can we please agree to remove the recommendation/requirement to  
> > declare  
> > > > variables at the start of a block of code?  
> > > > >
> > > > > I know that modern C standards allow to define variable in the middle.
> > > > > But I am strongly opposed to allow that in DPDK coding style.
> > > > > Such practice makes code much harder to read and understand (at least  
> > for  
> > > > me).
> > > >
> > > > Yes it is convenient to know that all variables are described
> > > > in a known place, just after function parameters.
> > > >
> > > > There is also a consistency concern.
> > > >
> > > > Old contributors like to be in a comfort zone,
> > > > 	and we don't want to lose old contributors.
> > > > New contributors may be refrained by old rules,
> > > > 	and we would like to get more new contributors.
> > > >
> > > > So that's a tricky decision.

Either way looks ok to me. See no need for hard and fast rules in this area.
But please no patches to change existing code.