On Wed, 18 Feb 2026 15:34:02 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. test/jdk/java/lang/management/RuntimeMXBean/InputArgument.java line 70: > 68: * @summary RuntimeMXBean.getInputArguments() handling of flags from > settings file. > 69: * > 70: * @author Oli Gillespie We try to avoid introducing new `@author` tags if possible. The git log and git blame is good enough for seeing who contributed code to a file. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/29793#discussion_r2823099238
