Just running a quick trial before and after I made this change in our project, we were previously seeing builds of our main target that took just under 13min. With this hack, a clean debug build takes about 4.5min.
Ben On Thu, Dec 1, 2016 at 1:33 PM, Ben Asher <benashe...@gmail.com> wrote: > Okay I think that worked! And just to clarify, you meant set > SWIFT_OPTIMIZATION_LEVEL = -Owholemodule and OTHER_SWIFT_FLAGS = -Onone ? > > I'll file a radar this afternoon with some details and DM you the number. > > Thanks again! > > Ben > > On Thu, Dec 1, 2016 at 1:10 PM, Jordan Rose <jordan_r...@apple.com> wrote: > >> Xcode needs to know that you're building in WMO mode, so rather than >> putting -whole-module-optimization in your "Other Swift Flags", put -Onone >> there. It's an ugly hack but it should work in the near term. >> >> We do want to work to make this drastic speed difference go away, so if >> you're able we (at Apple) would love to have a source drop of your Swift 3 >> project, for additional data on where the problems are. Mind filing a Radar? >> >> Best, >> Jordan >> >> >> > On Dec 1, 2016, at 11:51, Ben Asher via swift-dev <swift-dev@swift.org> >> wrote: >> > >> > Hello! Someone recently tipped me off to using >> -whole-module-optimization flag with -Onone for use during debug builds to >> speed up compile times. In our project, the speedup feels quite dramatic, >> but when it gets to the linking step (after compiling both Swift and Obj-C >> in the project) it fails because ld can't find the individual object files >> that normally get emitted during the debug-type build presumably because >> -whole-module-optimization only emits one (and this isn't a normal >> "-Owholemodule"-type build which works fine). >> > >> > I can't seem to reproduce this outside of Xcode, but I was curious if >> anyone has tried this and knows of a workaround to get >> -whole-module-optimization to work with -Onone in Xcode? >> > >> > I'm currently using Xcode 8.1 (App Store build) and Swift 3 on macOS >> Sierra. >> > >> > Thanks! >> > >> > Ben >> > _______________________________________________ >> > swift-dev mailing list >> > swift-dev@swift.org >> > https://lists.swift.org/mailman/listinfo/swift-dev >> >> > > > -- > Ben > -- Ben
_______________________________________________ swift-dev mailing list swift-dev@swift.org https://lists.swift.org/mailman/listinfo/swift-dev