On Feb 7, 2014, at 1:46 PM, Dmitri Gribenko <[email protected]> wrote:
> On Fri, Feb 7, 2014 at 9:39 PM, Argyrios Kyrtzidis <[email protected]> > wrote: >> On Feb 7, 2014, at 12:47 PM, Dmitri Gribenko <[email protected]> wrote: >> I wanted to avoid the need to do the atomic-rename dance. >> >> What is you concern with it ? > > No real concerns, just a bit more code to write. > >> What is the >> potential for mtime confusion that you see? We could provide a >> function in libclang to get the current timestamp so that clients >> don't have to invent their own, potentially incorrect way to get it. >> >> >> I really want to reduce complexity here and potential for out-of-sync, >> because now you have >> >> >> 1) The builder needs to provide an increasing timestamp by getting clock >> time (or libclang call ?) >> 2) we will compare that clock time with the file system modification time >> which can come from any kind of underlying file system >> >> >> vs >> >> 1) The builder needs to provide an increasing timestamp >> >> >> I much prefer the latter simpler approach. > > I can see how clients can break any of these while implementing (1) -- > for example, by using the local time instead of UTC time, and having > the build happen when the DST adjustment is made. But (2) is just an > OS-level thing, it can not go wrong. > > Also, imagine that we have a good client build system and a bad client > build system. A good client uses correct timestamps, a bad client > uses timestamps + 1 billion. Then after the bad client creates a > module, the good client will never rebuild it, because its timestamps > will always be "in the past”. A bad client will always be a problem but this is the responsibility of the builder, if the builder timestamps are self-consistent we don’t need to worry about any time changes or adjustments or what have you, it will not even need to be time based, we just don’t care. > > Dmitri > > -- > main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if > (j){printf("%d\n",i);}}} /*Dmitri Gribenko <[email protected]>*/ _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
