Apparently Buildship generates these when one uses Import -> Existing
Gradle Project:
<https://discuss.gradle.org/t/buildship-eclipse-plug-in-multiproject-builds/24030/5>.
We can use the Gradle "eclipse" plugin if customizations are
necessary, but my impression is that the intent is to treat ".project"
and ".classpath" as generated files, not sources to be tracked in
source control.
I was confused about the differences among:
srcDir 'foo'
srcDirs ['foo']
srcDirs = ['foo']
As it turns out, the first two append to the set of source
directories, while the last replaces this set entirely. I generally
want replacement, since WALA's current directory layout never matches
Gradle's assumed defaults.
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.
If multiple tests both write to "/tmp/cg.txt" (for example), then
these tests cannot safely run concurrently. That never used to be a
problem with Maven, since our Maven tests were all strictly sequential
anyway. But parallelized testing using Gradle requires that we do
better. Fortunately, Java has perfectly reasonable APIs for
generating uniquely-named temporary files and directories.
This task has an input named "hello_hash.ml", and an output named
"hello_hash.jar". So calling this task "generateHelloHash" is too
vague. Now we call it "generateHelloHashJar" instead.
We now download and verify checksums as a single task, rather than as
two separate tasks. This simplifies other task dependencies, since we
no longer have a checksum-verified "stamp" file separate from the
download itself. Unfortunately the combined task now has a
significant amount of repeated boilerplate. I'm hoping to refactor
that all out into a custom task class, but haven't yet figured out the
details:
<https://github.com/michel-kraemer/gradle-download-task/issues/108>.
We now also use ETags to be smarter about when a fresh download is or
is not actually needed. I think there are still opportunities for
improved caching here, but this is a step in the right direction.
This lets the "DynamicCallGraphTest" tests pass. The tests in that
class expect to find some element of the classpath that includes the
substring "com.ibm.wala.core.testdata". They then treat that as a
collection of bytecode files to instrument.
This should give us a set of mutually-consistent jars rather than
picking up random, outdated pieces from Maven Central or wherever else
I could find them. We now also have a single, central place where we
set the Eclipse version that we're building against. Much, *much*
cleaner.
Previously Buildship removed its classpath from all of these
launchers. Now it's automatically putting that back in as soon as I
visit each launcher in Eclipse's "Run Configurations" dialog. Not
sure what's going on here, but it certainly seems more sane to me to
assume that the Buildship-computed classpath *is* needed for all of
these. I have an open question on the Gradle discussion forum to try
to understand what's going on here and how to fix it:
<https://discuss.gradle.org/t/launchers-lose-buildship-classpath-on-import-regain-it-later/25641>.
A cleaned tree is now much closer to a pristine tree that has just
been checked out and never built. The only extra created files that
are left behind are ".gradle", "buildSrc/.gradle", and
"buildSrc/build".
<https://github.com/liblit/WALA/issues/5> notes that several
subprojects' tests are currently broken under Gradle. I'd still like
to be able to run non-broken tests, though. So here I'm disabling the
failing tests. The intent is to treat these exclusions as a to-do
list. We can remove exclusions as we get the corresponding tests
working. No more exclusions means
<https://github.com/liblit/WALA/issues/5> is fixed.
This consistently happens when I import WALA as an existing Gradle
project into Eclipse with Buildship. I don't really know what this
change means, or whether it's desirable. For now, I'm going to trust
Buildship and see what happens.
These settings files currently are generated with an initial timestamp
comment line, which is not something we'd want to track in version
control. Fortunately, the contents of these files are entirely
mundane, so there should be no problem with having Buildship generate
them anew each time a developer imports WALA into Eclipse as an
existing Gradle project.
Apparently Buildship generates these when one uses Import -> Existing
Gradle Project:
<https://discuss.gradle.org/t/buildship-eclipse-plug-in-multiproject-builds/24030/5>.
We can use the Gradle "eclipse" plugin if customizations are
necessary, but my impression is that the intent is to treat ".project"
and ".classpath" as generated files, not sources to be tracked in
source control.
I was confused about the differences among:
srcDir 'foo'
srcDirs ['foo']
srcDirs = ['foo']
As it turns out, the first two append to the set of source
directories, while the last replaces this set entirely. I generally
want replacement, since WALA's current directory layout never matches
Gradle's assumed defaults.
Eclipse's automated code clean-up tool did most of the heavy lifting
here: it specifically has a clean-up option for converting functional
interfaces to lambdas. I merely had to revert the automated changes
for a single enumeration class for which it produced invalid results,
and for a few test inputs that apparently aren't set up to be compiled
with Java 8.
These are all problems that Eclipse can detect, but that it detects no
instances of right now. Treating these as warnings instead of errors
should help prevent us from slipping backward in the future.
Casting to `Foo<Bar>` results in an unchecked-cast warning due to Java
generics type erasure. However, sometimes we don't really need a
`Foo<Bar>`, but could simply use any `Foo<?>`. Casting to the latter
creates no warning.
We already have plenty of examples of Serializable classes with this
field, and the vast majority of those fields have generated IDs rather
than "1L". From this I infer that using proper serialVersionUID
fields is considered appropriate WALA coding style.
One such annotation was unnecessary because the thing it was
suppressing no longer happens. Any future unnecessary warning
suppressions of this kind will now be treated as errors.
The other annotations were unnecessary because the corresponding
warnings have been disabled entirely in the Eclipse projects'
configurations. There seems to be no way to tell Eclipse to treat
these as anything other than "info" diagnostics in the future, so
that's how they will remain.
In general, my approach was to try to eliminate each unused parameter
using Eclipse's "Change Method Signature" refactoring. That did not
always succeed: a parameter may be unused in some base class method,
but then be used in subclass's override of that method. In cases
where refactoring to eliminate a parameter failed, I instead annotated
the parameter with '@SuppressWarnings("unused")' to silence the
warning.
Note: this group of changes creates a significant risk of
incompatibility for third-party WALA code. Some removed parameters
change externally-visible APIs. Furthermore, these changes do not
necessarily lead to Java compilation errors. For example, suppose
third-party code subclasses a WALA class or interface, overrides a
method, but does not annotate that method as @Override. Removing a
parameter means that the third-party method no longer overrides. This
can quietly change code behavior without compile-time errors or
warnings. This is exactly why one should use @Override wherever
possible, but we cannot guarantee that third-party WALA users have
done that.
Unnecessary "throws" declarations tend to cascade. If foo() calls
bar() and bar() falsely declares that it might throw IOException, that
often leads a programmer to declare that foo() might throw IOException
as well. Fixing the bar() throws declaration then reveals that we can
fix the foo() throws declaration too. By the time we reach a fixed
point with cleaning these up, we have removed roughly 320 unnecessary
throws declarations.
In a few cases, this cleanup even lets us remove entire "try
... catch" statements where the only thing being caught was an
exception that we now statically know cannot be thrown. Nice!
In Eclipse project configurations, upgrade any future such shenanigans
from warnings to errors. Now that we've fixed this, we don't want it
coming back again.
There is a potential drawback to this change. Conceivably some public
WALA API entry point might have declared that it could throw some
exception merely to reserve the *option* of throwing that exception in
third-party code that subclasses and overrides the API entry point in
question. I have no idea whether this is a significant concern in
practice, though.
The fix is to add "static" where appropriate, of course. I've also
simplified calls to such methods to reflect the fact that they no
longer need a specific object to call the method on.
In projects that contain test inputs, I've left the non-static
declarations unchanged, and instead downgraded the warning to be
ignored. In all other projects, this warning has been upgraded to an
error.
In general, these diagnostics are now errors in projects for which all
such warnings have been fixed. There are three unfixed warnings in
two projects, so this diagnostic remains a warning (not an error) in
those projects.
There are also many places where rwa-types-usage warnings have been
locally suppressed using @SuppressWarnings annotations. I haven't
systematically revisited those to see if any can be fixed properly.
So for those projects this diagnostic must also remain a warning (not
an error), since @SuppressWarnings does not work on things Eclipse is
configured to treat as errors.
Along the way, I also converted many "for (;;)" loops into modern
"for (:)" loops. I didn't systematically look for all opportunities
to do this, though. I merely made this change where I was already
converting raw Iterator uses into modern Iterator<...> uses.
Better use of generics also allowed many casts to become statically
redundant. I have removed all such redundant casts.
Only three raw-types warnings remain after this batch of fixes. All
three involve raw uses of CallGraphBuilder. I've tried to fix these
too, but it quickly snowballs into a cascade of changes that may or
may not eventually reach a statically-type-save fixed point. I may
give these last few problem areas another go in the future. For now,
though, the hundreds of other fixes seem worth keeping even if there
are a few stragglers.
This commit may change some public APIs, but only by making weaker
type signatures stronger by replacing raw types with generic types.
For example, we may change something like "Set" into "Set<String>",
but we're not adding new arguments, changing any
underlying (post-generics-erasure) types, etc.
There are two such diagnostics: one for collection methods and one for
equals(). See
<https://www.eclipse.org/eclipse/news/4.7/jdt.php#unlikely-argument-types>
for more information about these two new diagnostics.
For each of these diagnostics, I've set the severity level to
"warning" in projects that have some instances of the suspicious code,
or to "error" in projects that have no instances of the suspicious
code.
In regular application code, these warnings should be taken seriously
and fixed. But for test code, it's better to keep things simple and
not add any methods that aren't strictly needed by the test.
These should mostly be things that we've already decided earlier that
we explicitly don't want to "fix" because they simply disagree with
the WALA project's coding style.
The additional diagnostics are ones that were previously being
ignored, but which we seem to have been ignoring by default rather
than as a conscious choice.
For diagnostics of which we currently have *zero* instances, treat
these as errors rather than merely warnings. The intent is to
permanently lock out future regressions of things we've completely
fixed. In the future, whenever we fix the last instance of a given
warning in a given Eclipse project, we should also promote that
diagnostic to an error to keep things clean into the future.
Ben Liblit
Sungho Lee
Sungho Lee
Julian Dolby
Manu Sridharan
Raffi Khatchadourian
Manu Sridharan