[U-Boot] Discussion topics / issues

[Albert ARIBAUD]

Hi Jeroen,

On Fri, 10 Oct 2014 18:09:19 +0200, Jeroen Hofstee
<jeroen at myspectrum.nl> wrote:

> Hello Marek,
> 
> On 10-10-14 16:26, Marek Vasut wrote:
> > On Friday, October 10, 2014 at 04:04:40 PM, Jeroen Hofstee wrote:
> >> Hello Wolfgang,
> >>
> >> On 10-10-14 14:22, Wolfgang Denk wrote:
> >>>> It does not mention puts() vs. printf(), if it is indeed meant to be
> >>>> u-boot policy.
> >>> This is not just U-Boot philosophy, but something that I would
> >>> consider a matter of course when writing code - using the appropriate
> >>> tools for the task at hand.  If all you want to do is sendout a
> >>> constant string to the utput device, there is no need to invoke a
> >>> function that provides fancy formatting options.
> >>>
> >>> Don't we always try to use the smallest, most efficient tool that is
> >>> suited for a task?
> >> calling printf("%s\n", "string") gets translated into puts by the
> >> compiler. There should be no difference in the binary
> > Is this LLVM specific or does GCC do that too ? This is interesting information.
> 
> I was talking about gcc, it has been doing such since ages ago
> (unless you purposely disable it). clang does it as well.

That's a good thing, but generally speaking, I think that just because
the compiler is being clever doesn't mean we are allowed to rely on
that, because if we do take a habit of relying on the compiler being
clever, two things will happen:

1) we will keep thinking the compiler is being clever even when for
some reason it will stop being clever -- for instance, because someone
decided to disable the clever feature;

2) we will begin thinking the compiler is clever in situations where it
never has and never will.

IMO, a quick cost/benefit comparison of choosing between manually
turning printf() into puts whenever doable vs letting the compiler do
the changes automatically, the manual option wins -- it's bit like
Pascal's Wager: you don't lose much but you can only win.

> Regards,
> Jeroen
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Amicalement,
-- 
Albert.