Re: [Boost-build] Adding "on target" variables "on the fly"

Subject: Re: [Boost-build] Adding "on target" variables "on the fly"
From: Stefan Seefeld (stefan_at_[hidden])
Date: 2017-06-17 15:39:04

On 17.06.2017 10:24, Steven Watanabe via Boost-build wrote:
> AMDG
>
> On 06/17/2017 05:21 AM, Stefan Seefeld via Boost-build wrote:
>> <snip>
>> Here is the use-case:
>>
>> I'm trying to implement a config check that consists of this chain of
>> actions:
>>
>> 1) determine whether the given Python version has the "numpy" module
>> installed, and if so, report the associated include path
>>
>> 2) with that include path, try-compile a little app to make sure all
>> compiler flags work.
>>
>> The problem (in the original bjam logic) is that all "on target"
>> variables had to be defined before the scheduler's "update" function
>> (the "update_now" rule in Jam lingua) would be called. I.e., it isn't
>> possible for one target action to add or modify variables used in
>> another, unless the two were built by separate calls to the "update_now"
>> rule.
>> <snip>
> Can't you do this with __ACTION_RULE__?
> http://www.boost.org/build/doc/html/jam/language.html#jam.language.variables.builtins.actionrule

True, that might be another hook to use. (In my case however, I only use
that as a one-way notification operation to let the frontend know that
an action has been completed.)

Thanks,
        Stefan

-- 
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