RFR: 8349860: Make Class.isArray(), Class.isInterface() and Class.isPrimitive() non-native

[Roger Riggs]

On Tue, 11 Feb 2025 20:56:39 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> Class.isInterface() can check modifier flags, Class.isArray() can check whether component mirror is non-null and Class.isPrimitive() needs a new final transient boolean in java.lang.Class that the JVM code initializes.
> Tested with tier1-4 and performance tests.

src/java.base/share/classes/java/lang/Class.java line 807:

> 805:      */
> 806:     public boolean isArray() {
> 807:         return componentType != null;

The componentType declaration should have a comment indicating that == null is the sole indication that the class is an interface.
Perhaps there should be an assert somewhere validating/cross checking that requirement.

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PR Review Comment: https://git.openjdk.org/jdk/pull/23572#discussion_r1961869286