Re: [Boost-build] How to insert generated *.hpp files into dependency chain?

From: Vladimir Prus (ghost_at_[hidden])
Date: 2008-03-20 06:10:17

Jurko Gospodnetić wrote:

>    Hi Roland.
> 
>> Accidentally I dicovered that I need to output BOTH a *.cpp _and_
>> a *.hpp file from my generator. A hpp alone does not work.
>> ( Perhaps this should be mentioned somewhere, since codegeneratos
>> are a likely usage case. And for folks that favor header only
>> libs, a hpp only case is desirable.)
> 
>    I am not really sure what you mean by this. Boost Build generators in
> general have no special handling for cpp/hpp files... generated files
> could be xxx/yyy/zzz for all they care... So there must be something
> else that is not working for you and why you need the .cpp file...
> 
>    Could you possibly be lacking the <implicit-dependency> feature
> somewhere?

I remember a nasty thing that can be at play here. If a generator produces
HPP file which is not consumed by anything else, then you have a dangling
virtual target. At no time do we compute the filename of that virtual
target, and therefore that magic that sets includes dependencies on
the yet-to-generate targets does not work.

Qt support has some magic for that case, but I probably have to find
a generic solution.

- Volodya