Re: [Boost-build] prototyping alternative Boost.Build syntax

Subject: Re: [Boost-build] prototyping alternative Boost.Build syntax
From: Stefan Seefeld (stefan_at_[hidden])
Date: 2016-10-29 00:04:52

On 28.10.2016 13:11, Vladimir Prus wrote:
> Stefan,
>
>> I'm not sure. I have yet to figure out what the right boundary is to
>> interface with the build engine.
>> So let's assume I want to try both:
>>
>> * I want to prototype how to write metatargets in Python
>
> Then, you would need to:
>
> - Build b2 with Python support
> - Look at
> https://github.com/boostorg/build/blob/develop/src/build/project.py,
> like 150, where it loads Jamfiles.
> - Modify that place and/or load_jamfile method to support loading Python
>   modules

as reported, this leads to

error: unexpected exception
    descriptor 'difference' requires a 'set' object but received a 'list'

at ".../boost.build/src/build/generators.py", line 598, in convert_to_consumable_types

>
>> * I want to prototype how to write targets (to eventually replace all of
>> the above Boost.Build logic by suitable Python code).
>
> Modify
> https://github.com/boostorg/build/blob/develop/src/kernel/bootstrap.py
>
> so that the bootstrap function has:
>
>    bjam_interface = __import__('bjam')
>
>    bjam_interface.define_action("gcc.compile", "g++ -c -o $(<) $(>)")
>    bjam_interface.set_update_action("gcc.compile", "a.o", "a.cpp")
>
> Then, you'd go from there.
>

I have done this:

   ...
   bjam_interface = __import__('bjam')
   bjam_interface.define_action("gcc.compile", "g++ -c -o $(<) $(>)", [], 0)
   bjam_interface.call("gcc.compile", "hello.o", "hello.cpp")
  #return b2.build_system.main()

(I assume the invocation of 'b2.build_system.main()' is responsible for
locating Jamfiles and doing all the other stuff that I'd like to skip
when interfacing with the low-level API, yes ?)

This doesn't seem to do anything at all. At least it doesn't generate
"hello.o", and doesn't print any (error) message either. Is there any
command-line option I can use to cause the execution to be traced (I
tried "-d+2" and "--debug-building" with no visible effect).

Thanks,
        Stefan

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