On Wed, 4 May 2022 23:20:21 GMT, Maurizio Cimadamore <mcimadam...@openjdk.org>
wrote:
>> src/java.base/share/classes/java/lang/foreign/SymbolLookup.java line 153:
>>
>>> 151: static SymbolLookup loaderLookup() {
>>> 152: Class<?> caller = Reflection.getCallerClass();
>>> 153: ClassLoader loader =
>>> Objects.requireNonNull(caller.getClassLoader());
>>
>> Shouldn’t this be changed to throw `IllegalCallerException` instead of
>> throwing `NullPointerException` when the `caller`’s `ClassLoader` is
>> `null`[^1] or when `caller` itself is `null`[^2]?
>>
>> [^1]: This happens when `caller` is on the bootstrap classpath.
>> [^2]: This happens when `SymbolLookup.loaderLookup()` is called by native
>> code and no **Java** code is on the call stack.
>
> Good points. Regarding `ClassLoader` being null, I think we can still return
> something using the `BootLoader`'s `NativeLibraries` object - that would
> allow this method to be called internally. @mlchung Can you please confirm?
>
> As for the caller sensitive having no real caller (e.g. because method is
> called directly from native code), I think we should add a check in
> `Reflection::ensureNativeAccess`. Few weeks ago I verified that adding such a
> check does not compromise upcall stub created via the Linker interface (e.g.
> a Java upcall might require to perform restricted operations - but those
> operation always happen inside the upcall MH, which is always associated with
> some class).
Another option would be to treat calls to `ensureNativeAccess` with `null`
caller class as coming from unnamed module.
-------------
PR: https://git.openjdk.java.net/jdk/pull/7888
