Re: [Boost-build] Sorting include headers

Subject: Re: [Boost-build] Sorting include headers
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2008-10-15 14:59:30

AMDG

Alexander Sack wrote:
>> The same kind of problem has hit us a few times.  I usually try to fix
>> the code, because it just seems like a never-ending problem otherwise.
>> It can be a pain, but so are "random" compile problems when the order of
>> headers changes or a new library comes in with the same name.
>>     
>
> Yeah totally agree with you Philip but in order to evangelize a build
> tool I have to at least proof that bjam can build the exact pieces of
> code that autoconf and friends can (a true source of industry
> evilness).
>   

All right. how should include ordering work?
I don't think that it is a good idea to rely on
the order implicitly as include directories can be
specified in many different places.  If it actually matters,
the dependencies should be explicit.

Here's my best guess about the semantics:

a) It should be possible to say that one include directory comes before
another.
b) It should be possible to say that all the include directories in some 
group
come before all the directories in another group.
c) If a directory is specified more than once it should only be put in
the command line once and should obey the union of all constraints on it.
d) These constraints need to encoded in the property-set somehow--they
can't be global, as different targets may need different constraints.
e) It should at least be possible to make directories specified on
the command line come before directories that come from the jamfiles.

In Christ,
Steven Watanabe