Boxing a primitive using the constructor ("new Integer(4)") always
creates a distinct new boxed instance. That's rarely what you need,
and in fact all of those constructors have been deprecated in Java 9.
Using the static "valueOf" method instead ("Integer.valueOf(4)") can
give better performance by reusing existing instances. You no longer
get a unique boxed object, but generally that's OK.
"javah" was deprecated in Java 9, and has been removed entirely in
Java 10. The right way to generate headers now is by using the "-h"
flag to "javac". When "javac" is run in this way, it still generates
bytecode too. So ideally, we'd run "javac" just once to generate
bytecode and headers simultaneously. Fortunately, the Gradle JNI
plugin at <https://github.com/wpilibsuite/gradle-jni> help us do this
cleanly. Nice!
Previously we were compiling and linking "smoke_main", but not
actually running it as part of automated testing. I simply overlooked
this in the process of recreating the Maven build logic in Gradle.
Now we run "smoke_main" when testing, which turns out to be a pretty
good test of our management of both Java search paths as well as
linker / shared library search paths.
We now use "-rpath" on both Linux and macOS. This linker flag sets
the ELF RPATH on Linux, and the "@rpath" attribute on macOS, but
effectively it's doing the same thing, and that same thing is exactly
what we want. I think.
On Linux, we also now look for the JVM shared library in three
different places. The library has moved between Java 8 and 9, and
even on Java 9 it goes in a different place on Fedora 28 versus Ubuntu
16.04.
According to
<https://docs.gradle.org/current/userguide/native_software.html>,
"When you assemble dependents of a component, the component and all of
its dependents are compiled and linked, including any test suite
binaries." So it's intentional that the "assemble" task causes
creation of the smoke_main executable and xlator_test shared library.
Nothing TODO here; the current behavior is as designed.
The existing code worked fine under Java 8, but Java 9 fails to
resolve type constraints unless it has more explicit information about
at least one of the arguments to anyOf. Weird.
WALA itself does not use any JUnit 4.12 features. However, I am
working on a WALA-based project that does require JUnit 4.12. Mixing
jar versions is a path to madness. So if the WALA maintainers don't
mind, it would make my life easier if WALA itself required JUnit 4.12.
Otherwise, I need to maintain that 4.11/4.12 difference indefinitely
as a divergence between official WALA and my WALA variant.
I suppose an alternative could be to let the JUnit version be
specified externally somehow. I have not explored this option in
depth, but could look into it if simply moving to JUnit 4.12 is
undesirable.
Someone may have thought that we were ignoring these files, but we
aren't. From what I can tell, for these specific files, revision
tracking is intentional.
This follows an IntelliJ IDEA recommendation. Having the full
distribution allows IntelliJ IDEA to provide contextual help,
autocompletion, etc. for Gradle build scripts. The disadvantage, I
suppose, is that it imposes a larger download time on first use of
"gradlew".
New features that I like from this release: (1) better output grouping
when building in parallel, and (2) automatic test ordering to try
previously-failing tests first.
This gives the WALA maintainers the option of doing future 1.4.5+
releases from of a pre-Gradle branch if these merged Gradle changes
turn out to be more disruptive than expected.
The Eclipse metadata files created in this way are not identical to
those that Buildship would create when importing into Eclipse. The
tests in com.ibm.wala.cast.java.test.JDTJava15IRTests and
com.ibm.wala.cast.java.test.JDTJavaIRTests seem to pass using either
the Gradle-generated or the Buildship-generated versions.
As an aside, if you generate these files using Gradle first and *then*
import using Buildship, you end up with metadata that is identical to
what you would have had if you'd only imported with
Buildship. (There's one irrelevant difference in an unimportant
"<comment>" element.) So Maven's tests should run fine under any
wacky mix of Gradle- and Buildship-generated Eclipse metadata files.
That being said, I recommend not mixing build systems. WALA can be
built using either Maven, Gradle, or Eclipse+Buildship, but you're
probably better off only using one of these in any given build tree.
A mixed tree *should* probably work, but I haven't tested it
thoroughly, and consider better to avoid doing.
Incidentally, if there are other Maven-preparation steps that we'd
like Gradle to automate for us, that can now be done easily by
creating more "prepareMavenBuild" Gradle tasks in other subprojects
and adding the appropriate dependencies. For example, it would be
trivial to use this to automate downloading "/tmp/DroidBench",
installing the Android SDK, etc.
Julian Dolby
Ben Liblit