On Fri, 27 Feb 2026 15:11:02 GMT, Oli Gillespie <[email protected]> wrote:
>> Flags passed via a settings file (`.hotspotrc`, or `-XX:Flags=my-file`) do >> not have the `-XX:` prefix like they would have if passed as command-line >> args. `JVM_GetVmArguments` then prints these flags also without the prefix, >> along with command-line flags that _are_ prefixed. >> >> However, users of `JVM_GetVmArguments` expect the arguments to be in a >> format that they can pass as command-line args, for example [in CDS >> static_dump](https://github.com/openjdk/jdk/blob/63f00fff921ed4ac0f595a0a013d399700433a2c/src/java.base/share/classes/jdk/internal/misc/CDS.java#L329-L338) >> - CDS static_dump currently *does not work* if the main VM uses flags from >> a settings file. >> >> So, always add the `-XX:` prefix to flags from settings files in >> `JVM_GetVmArguments`. Updated existing test to cover this behaviour. >> >> I looked for existing users of `JVM_GetVmArguments` and they either seem >> like they'll benefit from this change (CDS, JMH via >> `RuntimeMXBean.getInputArguments()`) or they won't care. >> >> **Testing** >> >> * Updated the existing InputArgument test with a case that verifies the new >> behaviour. >> * Confirmed that CDS static_dump and JMH now work on a VM with flags from a >> file. > > Oli Gillespie has updated the pull request incrementally with one additional > commit since the last revision: > > Tidy 'no args' handling Marked as reviewed by kevinw (Reviewer). ------------- PR Review: https://git.openjdk.org/jdk/pull/29793#pullrequestreview-3867493213
