Re: Ccache depend mode

2019-05-11 Thread Luboš Luňák
On Thursday 09 of May 2019, Rene Engelhard wrote: > On Tue, May 07, 2019 at 11:32:12AM +0200, Luboš Luňák wrote: > > - We use -MMD, which exludes system headers (or even our externals, since > > for those we use -isystem too). This means that ccache could give > > incorrect hits if those headers ch

Re: Ccache depend mode

2019-05-09 Thread Rene Engelhard
On Tue, May 07, 2019 at 11:32:12AM +0200, Luboš Luňák wrote: > - We use -MMD, which exludes system headers (or even our externals, since for > those we use -isystem too). This means that ccache could give incorrect hits > if those headers change. That may seem bad, but I think it's unlikely to >

Re: Ccache depend mode

2019-05-07 Thread Michael Stahl
On 07.05.19 11:32, Luboš Luňák wrote: - We use -MMD, which exludes ... headers (or even our externals, since for those we use -isystem too). no, -isystem can't be used with bundled externals because it breaks incremental builds with -I we get deps on the headers [to be rewritten into dep

Ccache depend mode

2019-05-07 Thread Luboš Luňák
Hello, ccache 3.6 has introduced a new depend mode (CCACHE_DEPEND), in which ccache never uses preprocessing (gcc -E), which speeds things up on ccache misses. Previously ccache used the output from gcc -E to find out all the headers the source file depends on, in the depend mode it uses th