JDK next compilation error: incompatible types: Class<CAP#1> cannot be converted

[JasonFengJ9]

https://openj9-jenkins.osuosl.org/job/Build_JDKnext_aarch64_linux_OpenJDK/665/consoleFull

00:52:25  /home/jenkins/workspace/Build_JDKnext_aarch64_linux_OpenJDK/src/java.base/share/classes/java/lang/Double.java:462: error: incompatible types: Class<CAP#1> cannot be converted to Class<Double>
00:52:25      public static final Class<Double> TYPE = Class.getPrimitiveClass("double");
00:52:25                                                                      ^
00:52:25    where CAP#1 is a fresh type-variable:
00:52:25      CAP#1 extends Object from capture of ?

00:52:25  /home/jenkins/workspace/Build_JDKnext_aarch64_linux_OpenJDK/src/java.base/share/classes/java/lang/Short.java:82: error: incompatible types: Class<CAP#1> cannot be converted to Class<Short>
00:52:25      public static final Class<Short> TYPE = Class.getPrimitiveClass("short");
00:52:25                                                                     ^
00:52:25    where CAP#1 is a fresh type-variable:
00:52:25      CAP#1 extends Object from capture of ?
00:52:25  Note: Some input files additionally use or override a deprecated API.
00:52:25  Note: Some input files additionally use or override a deprecated API that is marked for removal.
00:52:25  Note: Some input files additionally use unchecked or unsafe operations.
00:52:25  9 errors

This is due to openjdk change ibmruntimes/openj9-openjdk-jdk@0995dd6

[github-actions]

Issue Number: 20428
Status: Open
Recommended Components: comp:vm, comp:test, comp:build
Recommended Assignees: keithc-ca, jasonfengj9, hangshao0

[pshipton]

I assume this is related to not using the latest bootjdk. We can back out the change until we are ready to move the bootjdk up.
@keithc-ca agreed?

[JasonFengJ9]

ibmruntimes/openj9-openjdk-jdk@0995dd6
from:

    /*
     * Return the Virtual Machine's Class object for the named
     * primitive type.
    static native Class<?> getPrimitiveClass(String name);

to:

    /*
     * Returns the Class object for the named primitive type. Type parameter T
     * avoids redundant casts for trusted code.
     */
    static native <T> Class<T> getPrimitiveClass(String name);

I think similar change is needed at

openj9/jcl/src/java.base/share/classes/java/lang/Class.java

Line 865 in 17ee5e7

public native Class<?> getComponentType();

[pshipton]

Oh ok. Are you going to fix it?

[keithc-ca]

I don't understand your comment about getComponentType(): I don't see how it could change and being public API, the signature must not change.

[JasonFengJ9]

getPrimitiveClass() invokes getComponentType().

openj9/jcl/src/java.base/share/classes/java/lang/Class.java

Lines 2950 to 2952 in 6fd3a8c

	static Class<?> getPrimitiveClass(String name) {
	if (name.equals("float")) //$NON-NLS-1$
	return new float[0].getClass().getComponentType();

A quick way to unblock the build is to do a cast there return (Class<T>) new float[0].getClass().getComponentType(); along with the API change static <T> Class<T> getPrimitiveClass(String name).

[keithc-ca]

I was hoping the solution could follow the pattern of forPrimitiveName(String) (using e.g. int.class), but that has bootstrap problems.

[keithc-ca]

I assume this is related to not using the latest bootjdk.

No, the same problem happens whether the bootjdk is Java 21 or Java 23.

[github-actions]

Issue Number: 20428
Status: Closed
Actual Components: comp:vm, test failure, blocker, jdk-head
Actual Assignees: No one :(
PR Assignees: keithc-ca