Re: [Boost-build] Call of interest

Subject: Re: [Boost-build] Call of interest
From: Konstantin Litvinenko (to.darkangel_at_[hidden])
Date: 2009-05-28 17:22:29

Steven Watanabe пишет:

> If you're already scanning the file for headers, I don't see that computing
> a hash will significantly reduce processing speed, since processing the
> file is most likely I/O bound anyway.

I can cache timestamps and #include and not rescan if timestamps are the 
same, as I do it now. With MD5 I should rescan always.

> A few times I have run into the following.
> 
> a) modify a file
> b) rebuild
> c) copy an older version of the file over the current version
> d) rebuild
> e) nothing happens because the timestamp of the file doesn't reflect the 
> fact that it has changed.
> 
> Another case:
> a) change a file
> b) rebuild
> c) change the file again before the next clock tick.
> d) rebuild
> 
> This can happen when you have an automated script invoking
> the build system multiple times, and the build is sufficiently fast.

Yes, that is the case. Well, than I should implement MD5 checker :)