Hi Erik,
looks good to me!
(Nit) You could consider the old TreeMap trick to ensure key-sorted map
iteration order:
// convert to a TreeMap to ensure sorted iteration order for (var e :
new TreeMap<>(map).entrySet()) { Thanks!
/Claes
On 2018-11-28 10:59, Erik Helin wrote:
Hi all,
this small patch ensures that two classes generated by jlink's
SystemModulePlugin (SystemModules$default and SystemModules$all) are
generated in a reproducible manner. That is, if you run jlink two
times in a row with identical input, then the generated classes from
both runs should be identical. This was almost the case already, the
only issue is that some code in SystemModulesPlugin.java are iterating
over Sets, and Set does not have a specified iteration order (the
iteration order did differ between runs).
This patch ensures that the iteration order over the sets is
well-defined by creating an ArrayList from the Set, sorting that
ArrayList and then finally iterate over the sorted ArrayList instead
of the Set.
For smaller programs jlink will now produce reproducible results, the
entire lib/modules file will be reproducible [0]. I have added a JTReg
test to verify this property (again, for smaller programs).
Webrev:
https://cr.openjdk.java.net/~ehelin/8214230/00/
Bug:
https://bugs.openjdk.java.net/browse/JDK-8214230
Testing:
- tier1, tier2 and tier3 on macOS, Windows, Linux (all x86-64).
- Run newly developed JTReg test on macOS, Windows, Linux (all x86-64).
- Run newly developed JTReg test with the fix absent and verified that
the test failed.
Many thanks to Alan Bateman for helping out with the patch!
Thanks,
Erik
[0]: https://reproducible-builds.org/docs/definition/
