Lots has changed since we forked Android's libcore, so merging the
latest upstream code has required extensive changes to the
Avian/Android port.
One big change is that we now use Avian's versions of
java.lang.Object, java.lang.Class, java.lang.ClassLoader, some
java.lang.reflect.* classes, etc. instead of the Android versions.
The main reason is that the Android versions have become very
Dex/Dalvik-specific, and since Avian is based on Java class files, not
dex archives, that code doesn't make sense here. This has the side
benefit that we can share more native code with classpath-avian.cpp
and reduce the amount of Java/C++ code duplication.
There's more work to do to derive all the properties of a given class
from its code source (e.g. JAR file), but this at least ensures that
ClassLoader.getPackage will actually return something non-null when
appropriate.
Previously, I used a shell script to extract modification date ranges
from the Git history, but that was complicated and unreliable, so now
every file just gets the same year range in its copyright header. If
someone needs to know when a specific file was modified and by whom,
they can look at the Git history themselves; no need to include it
redundantly in the header.
OpenJDK's java.lang.ClassLoader.getResource makes use of
sun.misc.Launcher to load bootstrap resources, which is not
appropriate for the Avian build, so we override it to ensure we get
the behavior we want.
The biggest change in this commit is to split the system classloader
into two: one for boot classes (e.g. java.lang.*) and another for
application classes. This is necessary to make OpenJDK's security
checks happy.
The rest of the changes include bugfixes and additional JVM method
implementations in classpath-openjdk.cpp.
In order to facilitate making the VM compatible with multiple class
libraries, it's useful to separate the VM-specific representation of
these classes from the library implementations. This commit
introduces VMClass, VMField, and VMMethod for that purpose.
