> On Jun 21, 2017, at 2:12 PM, Natthan Leong via swift-dev > <swift-dev@swift.org> wrote: > > Hi, > > As someone who also recently started contributing, I was surprised to discover > how much computing power was needed to build Swift. My first few build > attempts > on a mid-2014 rMBP took more than an hour with 100% CPU utilization which is > unsustainable for future participation.
A clean build of LLVM, swift, and the standard library takes a while, but most of the time you shouldn’t have to rebuild everything from scratch. For example if I’m just iterating on the compiler, I can edit a couple of source files and run ‘ninja swift’ and have a new compiler binary ready to test in a few seconds. I only rebuild the standard library if absolutely necessary, since that takes longer, but even then ‘ninja swift-stdlib’ is only a few minutes. Also I always do release builds during normal development, only doing a debug build if I have to run the debugger which isn’t very often. Release builds produce a faster swiftc, so the standard library is built faster, and also they link faster. Finally, it is possible to run only a subset of the validation tests while you’re iterating on a specific feature, instead of having to wait the ~15 minutes for ‘ninja check-swift-validation’, by directly invoking lit. Slava
_______________________________________________ swift-dev mailing list swift-dev@swift.org https://lists.swift.org/mailman/listinfo/swift-dev
