[QBS] A more general replacement for qbs-setup-xxx utilites

[Oswald Buddenhagen]

On Wed, Mar 25, 2015 at 02:19:55PM +0300, Aleksey Sidorov wrote:
> I think, that had accumulated enough hard coded tools to setup qbs
> profile. And I think more complex applications will want more of these
> utilities.
> 
> May be need to replace qbs setup tools with qbs script based solution?
> 
i think i managed to convince joerg that you are right. :)

the general idea is that all environment detection/adaptation should be
in "configure" parts of the modules it affects.
https://bugreports.qt.io/browse/QBS-24

profiles should be very thin containers with:
- environment variables
  - the default profile would just inherit the current environment
- a "dumb" set of module-specific properties of two kinds:
  - additional parameters that help the configure probes:
    - path to the compiler for the cpp (toolchain) module
    - path to qmake for the qt module
  - "selector" properties that help to decide which version of a module
    to use if multiple equally suitable builds are found (the discussion
    in https://bugreports.qt.io/browse/QBS-701 is pertinent. also,
    https://bugreports.qt.io/browse/QBS-192 requires a solution to the
    same problem at the project level)

> For example, some applications on unix wants to convert pkg
> config files to qbs modules or run some environment checks.
>
http://lists.qt-project.org/pipermail/qbs/2012-February/000033.html
http://lists.qt-project.org/pipermail/qbs/2012-September/000207.html

there is a whole bunch of jira tasks with comments (mostly written by me
:D) that concern configuration and use of modules, so you may want to
familiarize yourself with qbs' jira task list in general.

contributions in this area would be *very* welcome. ;)