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From: Vladimir Prus (ghost_at_[hidden])
Date: 2006-12-23 13:41:41

On Monday 11 December 2006 02:34, David Abrahams wrote:
> 1. cygwin-condition: there's a comment now, but it's still quite
> unclear. How should this argument be used? We need an example.
> I'm beginning to think it should look something like:
> <toolset>gcc
> The comment says, "should be a set of properties which are present
> when we're building with cygwin gcc," but (if my theory above is
> correct) that fails to indicate the primary distinguishing feature
> of the argument, which is that it must identify the cygwin-gcc
> toolset.

Ideally, the purpose of this argument is to be able to configure several versions
of python, and use a specific version only when specific properties are in build properties.
> 2. Also the comment says: "This argument is not used yet," but it
> clearly /is/ used. Code branches are followed based on its
> value.

That comment is not longer occurate.

> 3. The logic in this file that is used when the cygwin branch is
> followed seems to have been copy/pasted from the v1 python support,
> with all kinds of ends left dangling. For example, what do all the
> CYGWIN_PYTHON_DEBUG_* variable settings do? Nothing AFAICT.

Yeah, looks like cygwin support was never ported, because I don't have
cygwin to test anything. I think there are two possible issues:

1. We want to be able to configure several versions of python -- cygwin python,
msvc python, maybe mingw python. If that's needed, then declarations of all targets
in init-nt should include condition. Also:

        flags python.capture-output PYTHON : $(interpreter) ;

should become:

        flags python.capture-output PYTHON $(condition:J=/) : $(interpreter) ;

2. If we need cygwin-specific configuration logic we need to know when
cygwin python is initialized. Perhaps new value of 'flavour' feature -- 'cygwin',
can be used. So, for

        python 2.3 : /whatever : : : <toolset:gcc-flavour>cygwin ;

we'll know that cygwin python is initialized and adjust configuration code.

Does this help?

- Volodya

- Volodya


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