loadLibrary method signature should check that the class extends Library at compile-time, not runtime

[hakanai]

loadLibrary as of v4.4.0 currently looks like this:

{code}
public static T loadLibrary(String name, Class interfaceClass, Map<String, ?> options) {
if (!Library.class.isAssignableFrom(interfaceClass)) {
throw new IllegalArgumentException("Interface (" + interfaceClass.getSimpleName() + ")"
+ " of library=" + name + " does not extend " + Library.class.getSimpleName());
}
{code}

This allows code to compile but then throws an error at runtime, which is trappy. We hit this when we had a library defined as:

{code}
public interface Kernel32Custom extends WinNT
{code}

WinNT did extend Library in v4.0.0 but does not in v4.4.0.

Instead, the signature should just take <T extends Library>.

{code}
public static T loadLibrary(String name, Class interfaceClass, Map<String, ?> options) {
{code}

Then this change would have shown up as a compile-time error, making it possible to catch the issue much sooner.

[Groostav]

@trejkaz I believe JNA still targets pre 1.5 VM targets, so you'll notice there's a lot of features from newer language revisions (including generics) that JNA simply doesn't use.

[hakanai]

Not really a great excuse, given that the class in question is already using generics, but OK.

[matthiasblaesing]

@trejkaz nobody is apologizing. Indeed JNA uses generics and could be optimized. Feel free to suggest a fix (via PR). I just want to point out, that in the past (when generics were first introduced), decisions were made that were wrong in hindsight.

So when changes are suggested, backwards compatibility needs to be taken into account (at least on the binary level, but slight less important, on the source level).