[Scons-users] Using Validators

[Dirk Bächle]

Florian,

On 18.07.2014 11:16, Florian Lindner wrote:
> Hello,
>
> I have a Variable with an validator:
>
> vars.Add("compiler", "desc", "g++", validator=compiler_validator)
>
> def compiler_validator(key, value, environment):
>      if value in ["g++", "icc", "clang++"] or value.startswith("mpic"):
>          return True
>      else:
>          return False
>
>
> When called
> scons [...] compiler=clang
> the function above is called and returns False. Despite of that the
> compilation starts...
>
> [...]
>
> I suppose that return False on invalidate values is correctly, the validator
> is undocumented and the API states only the arguments, not the return type
> and semantics.
the MAN page gives an example for this. The return value of the 
validator method never gets checked, you have to throw an exception instead.

Best regards,

Dirk