On Sep 12, 2012, at 8:54 AM, Jonathan Gibbons wrote: > On 09/11/2012 10:46 PM, Fredrik Öhrström wrote: >> However, this begets the question why -Xprefer:source was added in the first >> place. If I remember correctly, >> this was over a year ago. It turns out that the default behavior for >> implicit compilation (which is necessary for sjavac:s multi core support) >> is to not recompile java source files when the class has a more recent >> timestamp than the source file. >> Sounds reasonable, until you realize that javac also takes into account the >> timestamps in rt.jar inside the jdk. >> Soooo, if you check out the source code on Monday, then download a newly >> built jdk on tuesday, >> and use this as the boot jdk, then the rt. jar timestamps will be newer than >> the source files you are trying to >> compile, and this somehow messes up the build! > > When you are compiling JDK, you should not be reading or in any way dependent > of the bootdir rt.jar (except insofar as it is needed to execute javac > itself.) The compilation itself should not read bootdir rt.jar. Indeed, you > should be able to set -Xbootclasspath to build/PLATFORM-ARCH/classes, which > will initially be empty. > > -- Jon
As I recall, I thought it was corba or jaxp or jaxws that needed needed -Xprefer:source because those early compiles could not just leave out the boot rt.jar??? -kto
