Response files issue

From: Vladimir Prus (ghost_at_[hidden])
Date: 2005-11-15 03:09:06

Hi!
I'm looking at up-to-date version of msvc.jam, and see this:

rule link ( targets + : sources * : properties * )
{
flags msvc.link LIBRARIES
[ common.resolve-library-files properties ] ;
}

I think this has two problems. 

1. The 'properties' argument to 'resolve-library-files' -- should 
not it be $(properties)? 

2. The use of "flags". I think this is very wrong. Essentially, it will
add the result of "common.resolve-library-files" to LIBRARIES var
that is applied to *all* msvc.link invokations later. Not just for
this target, or this project, but for all. Besides, it might be
problematic performance-wise. The 'flags' rule records everything in
a single list. Calling it 10000 times (once for each target), can slow
down things.

I'd suggest this:

LIBRARIES on $(targets) = [ common.resolve-library-files $(properties) ] ;

and even that is probably too complex. What about this:

flags msvc.link LIBRARIES_MENTIONED_BY_FILE : <library-file> ;

and using LIBRARIES_MENTIONED_BY_FILE right in the action? This should take 
care about conversion from V2 "virtual target" to jam "real target" 
automatically, because <library-file> feature is given "dependency" 
attribute. The "resolve-library-files" has the code to specifically exclude 
shared libraries, but it might be no longer necessary. (Alas, there's no 
comment to explain that logic -- my bad).

Say, I've just updated borland.jam to use new response files, and it passes 
all tests without this "resolve-library-files" call.

- Volodya

-- 
Vladimir Prus
http://vladimir_prus.blogspot.com
Boost.Build V2: http://boost.org/boost-build2