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Subject: Re: [Boost-build] dynamically editing the bjam dependency graph
From: Stefan Seefeld (stefan_at_[hidden])
Date: 2017-09-01 13:55:06

On 08/31/2017 11:39 PM, Steven Watanabe via Boost-build wrote:
> On 08/31/2017 09:10 PM, Stefan Seefeld via Boost-build wrote:
>> I'm still struggling with implementing the dynamic editing of the bjam
>> dependency graph (as outlined in
>> While I believe I
>> have worked out the Python frontend, the bjam backend isn't quite
>> cooperating the way I expect.
>> Consider this test code:
> The reason this fails is that dependencies
> are processed once by make1a, when the target
> is first pushed into the stack. This happens
> before 'gen' is executed, so the additional
> dependencies that it adds are ignored. Handling
> this correctly probably requires significant
> changes to make1.

If I understand correctly, the new dependencies need to be updated if
their dependants have a fate other than T_FATE_INIT, in which case
T_STATE_MAKE1A needs to be submitted for them.

So, whenever a new dependency is registered, I need to look at the fate
of the target, and if that's already being processed, I submit the
sources, too. That's what the attached patch does, and it does indeed
make my little test do what I expect.

Does this approach sound reasonable ? Am I overlooking some cases ?


      ...ich hab' noch einen Koffer in Berlin...

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