Re: inopportune rebuild

From: TEMPLIE Cédric (cedric.templie_at_[hidden])
Date: 2005-02-08 05:41:03

TEMPLIE Cédric wrote:
> David Abrahams wrote:
> 
>>TEMPLIE Cédric <cedric.templie_at_[hidden]> writes:
>>
>>
>>
>>>>Maybe, the "copy" command does not change the timestamps on files, so staged 
>>>>project2.h is always considered out of date with regard to .rsp and .obj 
>>>>files, which are generated, and so have current time as timestamp.
>>>>
>>>>What happens if you 
>>>>1. Built everything
>>>>2. Verify that this problem exists
>>>>3. Touch project2.h in your tree
>>>>4. Build again.
>>>>
>>>>After that, invoking bjam again should not copy project2.h.
>>>>
>>>>And a related question -- what command can be used to update timestamp on 
>>>>Windows. On Unix, it's just "touch", but that command is not present on 
>>>>Windows by default.
>>>>
>>>
>>>Thanks :) you are totally right, the timestamp is not changed, so it 
>>>tries to rebuild (copy) :(
>>>And it seems that it is the same for rsp files....
>>>The only way I found to change the date is to modify the file (like that 
>>>the modification access date change), but I am looking for a better 
>>>solution. I found some tools (a touch for windows) to do that, but these 
>>>tools are not natively with windows :(
>>>
>>>So have you got a solution to change the timestamp when copying, or 
>>>another idea ?
>>
>>
>> TYPE file1 > file2
>>
>>?
>>
> 
> 
> I try that, and in fact timestamps changed... :)
> What are the change to do for using TYPE instead of copy ? or maybe it 
> will be change for next milestone ?
> 
> Thanks again
> 
> TEMPLIE Cédric
> 

I use the cygwin cp, I just set the CP var in common.jam. Now my system 
works very better :)

Maybe that could be add in a documentation to explain that windows copy 
does not change timestamps, and it causes a lot of inopportune rebuilds...

But, again, thanks for your help.

TEMPLIE Cédric