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1 Commits

Author SHA1 Message Date
Roman Puchkovskiy
a7bc535e12 Fix native image build for the cases when io.netty.util.NetUtil is initialized at run-time (#10799)
Motivation:

In #10630, field substitutions were introduced for NetUtil.LOCALHOST4, NetUtil.LOCALHOST6 and NetUtil.LOCALHOST fields. They were required to allow a native image be built with most of Netty (including NetUtil) initialized at build time.

The substitutions created in #10630 only define getters, so the 3 fields can only be read in a native image.

But when NetUtil is initialized at run-time (this is what happens in #10797), its static initialization block is executed, and this block writes to all 3 fields. As the substitutions do not provide any setters, field stores are not valid, and such builds fail.

Modifications:

- Add netty-testsuite-native-image-client-runtime-init Maven module that builds a native image deferring NetUtil class initialization till run-time; this module is used to demonstrate the problem and verify the problem is gone with the fix
- Add no-op setters to substitutions for NetUtil.LOCALHOST4, NetUtil.LOCALHOST6 and NetUtil.LOCALHOST

Result:

A native image initializing NetUtil at run-time builds successfully.

Fixes #10797
2020-12-07 18:22:03 +01:00