[Scons-dev] prefix, bindir, datadir, libdir, etc.

[Pawel Tomulik]

W dniu 10.05.2014 18:18, Russel Winder pisze:

> On Sat, 2014-05-10 at 15:06 +0100, Russel Winder wrote:

> […]

>> Splendid, I shall take a look at this and what I have been working with

>> and see what the commonalities and differences are. First reaction is

>> that yours is a structured framework, and mine is a quick hack.

>

> First immediate thought:

>

> I have found it best to store values in a file rather than a command

> line: Autoconf/Automake and Waf have a configuration stage and a build

> stage so configuration stage options persist across all build

> executions.


Storing config in a file is supported by the library. Separating config 
and build phase should be easy - it's just about creating special target 
'configure' (and perhaps few other such as 'distclean' etc.) where SCons 
script would maintain config variables provided via commandline, perform 
autoconfiguration and cache its results using features of scons-gnu-build.


> SCons is build stage only and doesn't have a real way of

> persisting things.Yes, they should persist in the SCons database but I

> am not sure that works well as a user experience, much better to bring

> that persistence out explicitly in a file.

>


SCons implements command line variables 
(http://scons.org/doc/production/HTML/scons-user.html#sect-command-line-variables) 
which may be saved to a file. Well, ok it's kinda limited as it supports 
only strings, but I believe in most cases options/variables provided via 
command line are also strings, so it should be fine.

For auto-configuration SCons provides SConf module which is able to 
cache results of configuration. I use this feature heavily in 'feature 
test macros' implemented in scons-gnu-build, so results of 
autoconfiguration are also persistent between builds.

I use the scons variables mechanism in my library.


> So I would suggest that GVars need to be able to process a configuration

> file. Currently I just cheat and exec a Python script.

>


GVars support persistence/config files. See 
http://tomulik.pl/doc/user/manual.html#idp49434384 and 
http://tomulik.pl/doc/user/manual.html#idp49444128


Regards!
-- 
Paweł Tomulik