Java FFI: use class NitObject for references to Nit objects from Java

xymus commented 5 years ago

This PR improves the type safety of the Java FFI and fixes a bug with pointers to Nit objects at the same time.

The main change is the introduction of the Java class NitObject used as a general type for Nit objects referenced from Java code. It replaces the use of a simple int holding the pointer value, which was the source of the Java FFI bug.
Change internal pointers to Nit object to use the Java primitive types long instead of int, addressing to the same pointer bug. Only low-level services should still use long this way, in this case it is the support for Android that relies mostly on the FFI with C.
Change the annotation extra_java_files to accept the full name of Java classes (package + class) instead of the path to the Java source file. The compile still looks for the file in the same directory as the Nit module.
Clear up the documentation of the class ExternFile for filename to be relative to the compilation folder. This required updating previous usages.

privat commented 5 years ago

contrib/jwrapper/examples/queue seems to fail: https://gitlab.com/nit/nit-ci/-/jobs/168648150

privat commented 5 years ago

also tests/test_ffi_java_use_module.nit fails with nic --global

xymus commented 5 years ago

Fixed failing tests with global and semi-global compilation modes, and the use of custom CLASSPATH.

nitlang / nit