Re: [Boost-build] select-by-type

From: Jurko Gospodnetić (jurko.gospodnetic_at_[hidden])
Date: 2008-05-18 06:39:50

   Hi Adder.

>   In toolset/borland.jam (or a similar file), I need to modify
> 
>       rule link ( targets + : sources * : properties * )
>       {
>           ....
>       }
> 
>   in order to extract the sources of type OBJ in a separate variable.
> 
>   I tried using:
> 
>       echo [ virtual-target.select-by-type OBJ : $(sources) ] ;
> 
>   but I'm getting an error when building. On further investigation, it
>   turns out that $(sources[1]) is something like this:
> 
>       <p!-Bin\borland-5.6.0\debug\link-static\runtime-link-static\threading-multi\user-interface-gui\xcharset-ansi>Main.obj
> 
>   and it doesn't have a .type property (required by select-by-type).
>   It's not a "virtual target" object !
> 
>   How can I get the OBJ sources in a variable, so I can use it in the
>   "actions link ..." code ?

   I do not believe there is a 'clean' way to do what you want directly 
from the final target building rule like that. That rule gets only the 
Boost Jam target names representing all of the sources used. I guess you 
could parse those names to recognize .obj targets but that would not be 
a very robust solution since Boost Build offers no guarantees that it 
will construct those names the same in future versions.

   What you can do is implement a new generator class. In its run rule 
you get all the source targets as Boost Build's virtual-target objects
which you can then easily analyze to see if they are typed targets and 
what their type is. See the comments in generators.jam & targets.jam to 
get you started but as I recall that rule returns a list whose first 
parameter is a property-set object representing usage requirements to be 
applied to all dependent targets and the rest is the list of newly 
generated virtual targets.

   Hope this helps.

   Best regards,
     Jurko Gospodnetić