[sheepdog] [PATCH RFC] employ gnu99 style of GCC

[Liu Yuan]

On 04/29/2013 05:15 PM, Hitoshi Mitake wrote:
> This patch lets sheepdog employ gnu99 (C99 + gnu extensions) style of
> GCC. The main benefit of gnu99 is allowing interleaved statements and
> declarations. 

The idea doesn't look appealing to me. This will increase the complier
dependency and the payback is not that appealing.

> sheepdog source tree has many functions with lots of
> local variable declarations on their head part. They are harmful from
> the perspective of readability. Basically, variable declarations
> should be delayed until they are actually required. 

The readability is a much bigger topic than variable declarations.
Something matters more is how well we structure the internal algorithm,
abstractions and objects inside a subsystem, module or even a function.
The variable declarations matters to you, in my opinion because you
might assume a relatively big function such as more than 200 lines and
more than 5 parameters and dozens of local variables, which I am
personally highly against.

Most of time it is always easier to add statements into an existing
functions to add more features or fix bugs, or just lazy to add helpers
to abstract away the details because at the time one might think it is
obvious to put it in a big function. Many reasons contribute to the
bloated and hard-to-understand functions, but not the variable
declaration. If we always have functions smaller than, say 30 lines
(this is quite theoretical and just take it as a optional target), I
don't think we'll have problems that your patch aims to solve.

So instead of playing with variables, we are better off if we fix the
problems from the ground that if some functions doesn't looks
self-explanatory and complex with too many lines, parameters, variables,
it is the time to put it in a bigger picture and re-structure them.

Thanks,
Yuan