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Re: Reading the Riot Act To ARM's developers

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On 11/02/12 10:58, 7 wrote:
> Kelsey Bjarnason wrote:
>
>> [snips]
>>
>> On Tue, 07 Feb 2012 23:43:43 +0000, 7 wrote:
>>
>>> Typically the CMSIS library forces you to write code using hard coded
>>> numbers. So you want to set some flag to enable an interrupt it would
>>> read something like
>>>
>>> SYSCON->INT |= (1<<4)
>>>
>>> Here is the crunch, who the hell is going to know if its the 4th bit or
>>> the 14th bit when you got a million of these lines of code?
>>>
>>> Shortest possible answer NOBODY. Not even you!!!!!!!!!
>>>
>>> And then you change CPU, and something changes in hardware, how will you
>>> know what to look for - you gonna search for "4" all throughout the
>>> code?????
>>
>>
>> Are you actually using a tool so bad it doesn't let you define your own
>> symbols?
>>
>> define	INT_XMA	(1<<  4)
>>
>> ...
>>
>> SYSCON->INT |= INT_XMA
>>
>> Need to change INT_XMA?  Change it in one place, *every* usage of it
>> changes.  If your development tools can't cope with this - and, ideally,
>> with include files - then you should consider using a macro preprocessor
>> to generate the compilable code from the maintainable code.
>>
>> Either way, has nothing to do with ARM, per se; just to do with an
>> apparently crippled toolchain and/or a developer who can't look beyond
>> the trivial tool to see possible solutions.
>
>
> The point I was making has been snipped.
>
> The way I do it is independent of all these issues and much more verbose.
>
>
> #define INT_XMA (1<<  4)
> #define ENABLE_RS232  SYSCON->INT |= INT_XMA
>
>
> The problem I am having is what does that '4' mean. Is it 4 or 14 or
> something else? I need a datasheet. Thats just crap programming.
>
> What I want to be able to do is
>
> #define ENABLED 1
> #define ENABLE_RS232_INTERRUPT  SYSCON.INT.INT_XMA = ENABLED
>
> or something similar which is what PIC libraries do.
> The flag has been defined for you so that you don't have to figure
> out INT_XMA is (1<<  4) or (1<<  14) sifting through a datasheet.
> When a CPU is changed, the magic of giving names to flags
> still works and saves a lot of time when checking.
>
>
> If you care to look at the support forums and sample code,
> you will also find most programmers set multiple flags
> with one setting.
> That makes the problem 100 times worse because its even more
> work trying to figure out which flags have been set.
>
> The programmers who wrote the CMSIS libraries should be shot
> and replaced with programmers who are a little more wiser.
> They should spend more time with compiler writers that support
> ARM to make sure that everybody sings from the same song sheet.
>
>

I would recommend a useful little feature that most programming 
languages support - "comments".

Magic numbers are a problem if the same number is used several times in 
a program, or if they are used without explanatory comments.  But with a 
comment explaining what "(1 << 4) | (1 << 14)" means in this situation, 
it is perfectly good programming.

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Re: Reading the Riot Act To ARM's developers Kelsey Bjarnason <kbjarnason@gmail.com> - 2012-02-10 21:22 -0800
  Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-11 09:58 +0000
    Re: Reading the Riot Act To ARM's developers David Brown <david.brown@removethis.hesbynett.no> - 2012-02-11 15:16 +0100
      Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-12 00:56 +0000
        Re: Reading the Riot Act To ARM's developers David Brown <david.brown@removethis.hesbynett.no> - 2012-02-12 10:24 +0100
          Re: Reading the Riot Act To ARM's developers "Ezekiel" <zeke@nosuchemail.com> - 2012-02-12 08:21 -0500
          Re: Reading the Riot Act To ARM's developers 7 <email_at_www_at_enemygadgets_dot_com@enemygadgets.com> - 2012-02-12 19:12 +0000
            Re: Reading the Riot Act To ARM's developers Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2012-02-13 08:54 +0200
            Re: Reading the Riot Act To ARM's developers David Brown <david@westcontrol.removethisbit.com> - 2012-02-13 09:12 +0100
    Re: Reading the Riot Act To ARM's developers Kelsey Bjarnason <kbjarnason@gmail.com> - 2012-02-11 10:34 -0800

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