Re: [ECOS]How to run testprograms for lwip

[Simon Kallweit <simon.kallweit@intefo.ch>]

Sergei Gavrikov wrote:
> On Thu, Jul 30, 2009 at 10:10:53AM +0100, David Fernandez wrote:
>> May be I'm wrong, but I think that the macro CYG_FUN_LWIP_IP_FORWARD
>> is not only defined, but defined as 1 if the option is enabled. May be
>> that what you want is to use the macro directly instead of the
>> preprocessor operator applied to it.
> 
> As fae as I remember, that depends on CDL flavor type. The value can be
> either not defined at all, or it can be defined as 
> 
> #define CYG_FOO 1
> 
> or it can be defined as
> 
> #define CYG_FOO 1
> #define CYG_FOO_1
> 
>> That is simpler than defining another macro, and if the option is
>> disabled, the macro would be defined, but its value would be 0.
> 
> Sure. But goal is do not tweak the ported sources, so there are the same
> odd wrappers.
> 
>> You might want to check it this way though, in case the lwip is
>> included, but those CDL options are not active for some reason...
>> which may be impossible, but here you are.
>>
>> #ifndef CYG_FUN_LWIP_IP_FORWARD
>> #define IP_FORWARD 0
>> #else
>> #define IP_FORWARD CYG_FUN_LWIP_IP_FORWARD
>> #endif
> 
> It's resonable. And I would prefer yet another way (CDL way):
> 
> cdl_package CYGPKG_BAR {
>     ...
>     cdl_option CYGOPT_HAVE_FOO {
>         display         "Foo feature"
>         flavor          bool
>         default_value   1
>         # Original bar sources want it:
>         define          HAVE_FOO
>         description     "
>             Enable this option to use foo feature."
>     }
>     ...
> }
> 
> Then in <pkgconf/bar.h>
> 
> will apear or won't
> 
> #define CYGOPT_HAVE_FOO 1
> #define HAVE_FOO 1
> 
> In our case we would include at the end of lwipopts.h an inclusion
> 
> #ifdef __ECOS__
> # include <pkgconf/net_lwip.h>
> #endif
> 
> and it will be contain, e.g.
> 
> #define CYGFUN_IP_FORWARD 1
> #define IP_FORWARD 1
> 
> or nothing. Etc.
> 
> May be I wrong too. So, it seems for me it's a time to re-read CDL guide
> :-)

I think there are a few pitfalls we have to deal here. CDL does only 
emit the #defines when the boolean is true, otherwise it won't emit 
#defines (also true for additional defines). If we want to go that 
route, we would have to make sure that the CDL's defaults are also the 
defaults of the lwip's opts.h file, which in my opinion is not a good 
solution to maintain. But I think what we could do is something like

cdl_option CYGOPT_IP_FORWARD {
     display         "IP forwarding"
     flavor          bool
     default_value   1
     define          IP_FORWARD
}

and then in lwipopts.h only have:

#ifndef IP_FORWARD
# define IP_FORWARD 0
#endif

That would probably make things a bit easier. I don't know if it would 
work as a general solution though, would have to check that. But I'm 
just getting ready for my holidays :)

Simon

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