Summary

Modify the -XshowSettings launcher option to print non-verbose settings details of all components by default. Verbose settings details will be printed via the -XshowSettings:all option. Modify the -XshowSettings option to reject bad values passed to it. Print an error message in such scenarios and abort the VM launch.

Problem

The recent security (JDK-8281658) and locale (JDK-8310201) component contributions made for the -XshowSettings launcher option introduced the concept of verbose and non-verbose settings output for some components (locale, security). The new security component rejects bad sub-component options passed to it by printing a warning message. To be consistent, the main -XshowSettings option should implement a similar approach.

The current default behaviour prints verbose settings information. That's a lot of detail for users that might be just looking for a summary. The current launch option also allows bad input options to be passed to it. In such a scenario, it defaults to printing all settings information.

Solution

Modify the default -XshowSettings launcher option behaviour to print non-verbose settings information on all components.

• -XshowSettings will print non-verbose settings information.
• -XshowSettings:all will print verbose settings information on all components.

Have the launcher option reject bad component values. If bad component values are detected, the VM launch will be aborted and an error message is printed. A similar change will occur for the new security sub-options that were added recently. If a bad sub-option is detected, the VM will abort rather than continue to launch.

Specification

-XshowSettings will default to printing the non-verbose variant on all component settings available. -XshowSettings:all will print verbose settings information on all component settings available.

Supported components values, when specified, will continue to print verbose settings for that component.

Bad options such as -XshowSettings:bad will no longer print any settings information. Instead an error message is printed and the VM launch is aborted.