[ccache] Why not cache compile failures?
ams at codesourcery.com
Fri Oct 5 03:10:42 MDT 2012
On 30/09/12 02:23, Martin Pool wrote:
> Depending on the compiler, it may be possible to see from the
> waitstatus that it was interrupted, and so to avoid caching the
> result. Or, perhaps you can do something with process groups to let
> ccache observe the interrupt signal itself and so be sure not to cache
Yes, I think it's probably reasonable to only cache failures where the
return code is not a signal. The compiler does handle SIGSEGV ("Internal
compiler error") but not other signals, I think, so that works out quite
> If you emit a message when printing a cached error it ought to be safe
> enough to experiment with.
Agreed, I was thinking of something like this:
file.c: warning: This compile failure has been cached by ccache.
file.c: warning: Set CCACHE_RECACHE=1 to try the compiler again.
> As much as possible we want things to be pure functions of the input,
> both in the input to ccache, and in how ccache itself behaves.
Agreed, I hate it when I spend all day trying to figure out what's
broken, and then tomorrow it just works. Sure, I'm unstuck, but I've
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