Update FFI related code for compilation in JDK20

[ChengJin01]

The change is to update the code specific to FFI in OpenJDK
to ensure it gets compiled in JDK20 as we have been working
on the changes in OpenJDK & OpenJ9 to deal with the latest
APIs intended for JEP434.

Commit 1: Replace part of FFI APIs with the latest APIs in JDK20
Commit 2: Disable FFI related code in OpenJDK for JDK20

Note:
Further changes for all FFI related code in JEP434/JDK20 will be made via eclipse-openj9/openj9#16329.

Signed-off-by: ChengJin01 jincheng@ca.ibm.com

[tajila]

@tajila do you have any concerns with 7fa5db1c1d16 ?

@pshipton No concerns

[pshipton]

Pls fix the PR title and description to cover both of the commits.

[ChengJin01]

Pls fix the PR title and description to cover both of the commits.

The PR title plus description is updated accordingly as requested.

[pshipton]

@keithc-ca did you get all the changes you requested?

[keithc-ca]

@keithc-ca did you get all the changes you requested?

Almost: #12 (comment)

[keithc-ca]

@ChengJin01 Can you remove the redundant uses of "[FFI]" in the commit messages and descriptions of this and eclipse-openj9/openj9#16585, please?

[ChengJin01]

@ChengJin01 Can you remove the redundant uses of "[FFI]" in the commit messages and descriptions of this and eclipse-openj9/openj9#16585, please?

Removed as suggested above.

[keithc-ca]

This doesn't compile in its current state; make java.base-java yields errors like:

jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/ppc64/aix/AixPPC64Linker.java:63: error: non-static method arrangeDowncall(MethodType,FunctionDescriptor,LinkerOptions) cannot be referenced from a static context
        return CallArranger.arrangeDowncall(inferredMethodType, function, options);
                           ^
jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/ppc64/aix/AixPPC64Linker.java:68: error: non-static method arrangeUpcall(MethodHandle,MethodType,FunctionDescriptor,SegmentScope) cannot be referenced from a static context
        return CallArranger.arrangeUpcall(target, targetType, function, scope);
                           ^
jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/ppc64/sysv/SysVPPC64leLinker.java:63: error: non-static method arrangeDowncall(MethodType,FunctionDescriptor,LinkerOptions) cannot be referenced from a static context
        return CallArranger.arrangeDowncall(inferredMethodType, function, options);
                           ^
jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/ppc64/sysv/SysVPPC64leLinker.java:68: error: non-static method arrangeUpcall(MethodHandle,MethodType,FunctionDescriptor,SegmentScope) cannot be referenced from a static context
        return CallArranger.arrangeUpcall(target, targetType, function, scope);
                           ^
jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/s390x/sysv/SysVS390xLinker.java:63: error: non-static method arrangeDowncall(MethodType,FunctionDescriptor,LinkerOptions) cannot be referenced from a static context
        return CallArranger.arrangeDowncall(inferredMethodType, function, options);
                           ^
jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/s390x/sysv/SysVS390xLinker.java:68: error: non-static method arrangeUpcall(MethodHandle,MethodType,FunctionDescriptor,SegmentScope) cannot be referenced from a static context
        return CallArranger.arrangeUpcall(target, targetType, function, scope);
                           ^
jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/x64/sysv/SysVx64Linker.java:57: error: non-static method arrangeDowncall(MethodType,FunctionDescriptor,LinkerOptions) cannot be referenced from a static context
        return CallArranger.arrangeDowncall(inferredMethodType, function, options);
                           ^
jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/x64/sysv/SysVx64Linker.java:62: error: non-static method arrangeUpcall(MethodHandle,MethodType,FunctionDescriptor,SegmentScope) cannot be referenced from a static context
        return CallArranger.arrangeUpcall(target, targetType, function, scope);
                           ^
jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/x64/windows/Windowsx64Linker.java:57: error: non-static method arrangeDowncall(MethodType,FunctionDescriptor,LinkerOptions) cannot be referenced from a static context
        return CallArranger.arrangeDowncall(inferredMethodType, function, options);
                           ^
jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/x64/windows/Windowsx64Linker.java:62: error: non-static method arrangeUpcall(MethodHandle,MethodType,FunctionDescriptor,SegmentScope) cannot be referenced from a static context
        return CallArranger.arrangeUpcall(target, targetType, function, scope);
                           ^
10 errors

[ChengJin01]

This doesn't compile in its current state; make java.base-java yields errors like:

This is because we removed static from arrangeDowncall() & arrangeUpcall() in CallArranger.java

Please note the static keyword remains arrangeDowncall & arrangeUpcall for the last changes in JDK20.

e.g.
https://github.com/ibmruntimes/openj9-openjdk-jdk20/blob/master/src/java.base/share/classes/jdk/internal/foreign/abi/x64/sysv/CallArranger.java#L122

 --->    public static MethodHandle arrangeDowncall(MethodType mt, FunctionDescriptor cDesc, LinkerOptions options) {
...
        return handle;
    }

---> public static MemorySegment arrangeUpcall(MethodHandle target, MethodType mt, FunctionDescriptor cDesc, SegmentScope scope) {
 ...
return UpcallLinker.make(CSysV, target, bindings.callingSequence, scope);
    }

which means we need to restore static back to the two methods.

[ChengJin01]

As discussed with @keithc-ca offline, we have to restore static on X64 (Linux & Win) (which remains unchanged since JDK16) and on Power & zLinux which follow the pattern on X64 (there was compilation error on Aarch64 because we removed static in there to keep consistent with the existing signature of methods in CallArranger on Aarch64). (Restored at 7608d05)

As for the non-static methods on Aarch64 in which static was removed since JDK18, I think it is specific to Hotspot but inappropriate for OpenJ9 given the underlying code at java level remain the same on all supported platforms.

[ChengJin01]

I double-checked the code at https://github.com/ibmruntimes/openj9-openjdk-jdk20/blob/master/src/java.base/share/classes/jdk/internal/foreign/abi/aarch64/CallArranger.java#L99

    public static final CallArranger LINUX = new LinuxAArch64CallArranger();
    public static final CallArranger MACOS = new MacOsAArch64CallArranger();

and

openj9-openjdk-jdk20/src/java.base/share/classes/jdk/internal/foreign/abi/aarch64/linux/LinuxAArch64Linker.java

Line 59 in 96afd1c

protected MethodHandle arrangeDowncall(MethodType inferredMethodType, FunctionDescriptor function, LinkerOptions options) {

    protected MethodHandle arrangeDowncall(MethodType inferredMethodType, FunctionDescriptor function, LinkerOptions options) {
        return CallArranger.LINUX.arrangeDowncall(inferredMethodType, function, options); <----
    }

    @Override
    protected MemorySegment arrangeUpcall(MethodHandle target, MethodType targetType, FunctionDescriptor function, SegmentScope scope) {
        return CallArranger.LINUX.arrangeUpcall(target, targetType, function, scope); <----
    }

The reason why the instance method arrangeDowncall/arrangeUpcall is invoked from the Linker on Aarch64 is that a CallArranger instance (namely CallArranger.LINUX for Linux or CallArranger.MACOS for macOS) is already created in CallArranger in advance as the code in CallArranger is shared by Linux and macOS, which is different from the CallArranger on x64. e.g. Linux/x64 in https://github.com/ibmruntimes/openj9-openjdk-jdk20/blob/master/src/java.base/share/classes/jdk/internal/foreign/abi/x64/sysv/SysVx64Linker.java.

    protected MethodHandle arrangeDowncall(MethodType inferredMethodType, FunctionDescriptor function, LinkerOptions options) {
        return CallArranger.arrangeDowncall(inferredMethodType, function, options);
    }

    @Override
    protected MemorySegment arrangeUpcall(MethodHandle target, MethodType targetType, FunctionDescriptor function, SegmentScope scope) {
        return CallArranger.arrangeUpcall(target, targetType, function, scope);
    }

where there is no CallArranger instance created for Linux or Win on x64 given CallArranger on Linux is different from Windows.

Based on the setting above in OpenJDK, it's correct for the latest changes (already done in 7608d05) in which case non-static arrangeDowncall/arrangeUpcall of CallArranger is only intended for Aarch64 while static arrangeDowncall/arrangeUpcall of CallArranger is intended for x64, Power and zLinux.

[keithc-ca]

Jenkins compile alinux64 jdk20 depends eclipse-openj9/openj9#16585