Re: [Boost-build] [BBV2] Cache SHELL output during parse/location of generated files

From: aulwelling_at_[hidden]
Date: 2007-03-13 12:28:43

ping 

> -----Original Message-----
> From: aulwelling 
> Sent: Wednesday, March 07, 2007 11:49 AM
> To: 'boost-build_at_[hidden]'
> Subject: [BBV2] Cache SHELL output during parse/location of 
> generated files
> 
> I am trying to improve the performance of our builds by 
> caching the results of system commands that run during the 
> parse stage to determine which source files to include in 
> various libraries.
> 
> Some background:
> 
> I have a custom rule to generate a shared library from a 
> large set of files.  Separate text files contain the list of 
> functions actually needed for that library.  The functions 
> are generally in separate source files.  I added some SHELL 
> commands to the rule so that we will grep through the text 
> files and determine which source files to include in the 
> library.  This ends up taking quite a lot of time when 
> building, so I thought I'd try to save the results of the 
> grep to a file.
> 
> I have run into 2 main problems:
> 
> First, I can't figure out a nice boost way to save the grep 
> results in a file, because I need to results of the grep 
> during the parsing stage, but any files I generate using 
> boost rules will only get created during the update stage.  I 
> tried using the make rule to generate a new file with the 
> results of the grep in it and then just cat this file in my 
> rule, but I don't think this will work due to the parse then 
> update nature of boost.  If someone has a good solution to 
> this I'd love to try it.
> 
> This led to my second problem.  I decided I'd need a separate 
> script/rule/whatever to run the grep commands if the file 
> doesn't needs updating or just cat the file if everything is 
> up to date.  I'd like this file to end up in the same place 
> as my .o and .so files.  How do I determine the current 
> output directory for built targets (meaning 
> build-dir/.../linux/gcc/debug or whatever) so I can pass it 
> to my rule/script?
> 
> I'd greatly appreciate any help with either of these issues.
> 
> Thanks,
> Ashley
>