Re: [Boost-build] Dependency scanning bug

From: K. Noel Belcourt (kbelco_at_[hidden])
Date: 2007-12-11 10:01:49

Hi Philip,

On Dec 10, 2007, at 1:03 PM, Phillip Seaver wrote:

> I don't have the latest version of boost-build (looks like I  
> imported it
> from the May 15th nightly release), but I couldn't find a similar  
> bug in
> the tracker.
>
> One of my co-workers ran into an interesting problem.  He had a
> directory named "new" in one of his source directories.  Every time he
> modified the "new" directory, it caused most (if not all) of the C++
> files to be rebuilt.  The reason is that it was looking at the  
> timestamp
> of the "new" directory (instead of the system "new" include, I  
> believe)
> and seeing that it was newer than the object files.
>
> Is it possible/reasonable to exclude directories from dependency  
> scanner
> matching?

Yes, we had to do the exact same thing.  Here's an email I sent to  
Rene showing how we did it.

Begin forwarded message:
> From: "K. Noel Belcourt" <kbelco_at_[hidden]>
> Date: August 22, 2007 8:41:56 AM MDT
> To: Rene Rivera <grafikrobot_at_[hidden]>
> Subject: Patch to eliminate directories from the build dependencies
>
> Hi Rene,
>
> A while ago, I mentioned that we found a problem with bjam where it  
> was depending on the directory time stamps.  Our environment is  
> intolerant of this since directory timestamps are updated whenever  
> a file in the directory is modified (in our case, non-source files  
> are modified and this causes things to rebuild).  Our solution was  
> to set all directory timestamps back to one (1), effectively  
> eliminating them from the dependency graph.
>
> The attached patch to the trunk will introduce this same behavior.   
> It also eliminates an unused variable.  I don't know if you want to  
> put this into bjam but at one point I told you I'd send you this  
> patch, so here it is.
>
> -- Noel
>
>



>