Re: [boost] big problem with dependency changes

Subject: Re: [boost] big problem with dependency changes
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2014-06-17 19:23:34

On 18/06/2014 09:29, Bjørn Roald wrote:
> On 06/17/2014 10:46 AM, Peter Dimov wrote:
>> When I edit in boost/ - which I never do - when I run the tests, b2 then
>> sees the file as modified, but does not update the link in boost/ (the
>> link being newer than the source in include/.)
>>
>> When I edit in include/ - which is what I do - b2 sees the file as
>> modified and updates the link in boost/ to point to it.
>
> Good!
> but even if all are fixed, it is not good to have these subtle issues
> where users have to be careful.  Part of the problem is that many tools
> such as IDE's with built-in symbol browsing, debugers etc. will lead
> users to those headers they should not edit.

Perhaps b2 could check both timestamps are equal and sync 
bidirectionally?  Copied or hardlinked files should have the same 
timestamp (not sure about symlinks, but they should probably be ignored 
anyway since they won't have this issue), and both manually edited or 
freshly git-updated files should have a newer timestamp than their 
counterpart (modulo possible 2 second filesystem resolution).

The only thing I can envisage possibly tripping this up is if someone 
untars/unzips a fresh release build over the top of their existing tree, 
which could potentially have older timestamps than the counterpart 
files, if the user has been editing them.  (Especially if they're using 
the same release build as previous, to try to revert to originals.)  But 
that seems like a case in which users ought to have cleaned the tree 
first in any event, and shouldn't be an issue for upgrades, as those 
have different dir names embedded in the archive.

Although I suspect most users using release builds will not run b2 more 
than once anyway.