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.
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.
If a method is private, there's no risk that a subclass elsewhere
might be overriding it and depending on dynamic dispatch to choose the
right implementation. So all of these private methods can safely be
declared static without risk of regression in either WALA code or
unseen third-party code.
Instead, rely on Java's ability to infer type parameters in many
contexts. This removes 665 Eclipse warnings.
Note: a few of these changes are to files under "test" subdirectories.
Presumably those are files that serve as test inputs rather than being
part of WALA code proper. As far as I can tell, these changes do not
break any WALA tests. But if any of those tests were specifically
intended to exercise WALA on code with non-inferred generic type
parameters, then I really should be leaving those alone.
The new project only depends on the minimal Eclipse plugins to make the
ECJ frontend work. Hence, it should be amenable to creating a Maven
Central jar.
com.ibm.wala.cast.js.rhino.test/harness-src/com/ibm/wala/cast/js/test/TestPrototypeCallGraphShapeRhino.java
com.ibm.wala.cast.js.test/harness-src/com/ibm/wala/cast/js/test/TestPrototypeCallGraphShape.java
com.ibm.wala.cast.js.test.data/examples-src/pages/prototype.html
work (not yet finished) on fixes to property accesses for JavaScript:
com.ibm.wala.cast/source/java/com/ibm/wala/cast/ipa/callgraph/AstSSAPropagationCallGraphBuilder.java
com.ibm.wala.cast.java/src/com/ibm/wala/cast/java/ipa/callgraph/AstJavaSSAPropagationCallGraphBuilder.java
com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/ipa/callgraph/JSSSAPropagationCallGraphBuilder.java
currently unused tests to remind me to fix bugs:
com.ibm.wala.cast.js.test/harness-src/com/ibm/wala/cast/js/test/TestSimpleCallGraphShape.java
com.ibm.wala.cast.js.test.data/examples-src/tests/loops.js
com.ibm.wala.cast.js.test.data/examples-src/tests/primitive_strings.js
fixes to exception handler code generation in JavaScript:
com.ibm.wala.cast.js.rhino/source/com/ibm/wala/cast/js/translator/RhinoToAstTranslator.java
com.ibm.wala.cast.js.test.data/examples-src/tests/try.js
com.ibm.wala.cast.js.test/harness-src/com/ibm/wala/cast/js/test/TestSimpleCallGraphShape.java
fixes to make the system build on both juno and luna
com.ibm.wala.cast.js.test.data/pom.xml
pom.xml
targets/e42/e42.target
targets/e44/e44.target
targets/pom.xml
com.ibm.wala.core.tests/META-INF/MANIFEST.MF
com.ibm.wala.dalvik.test/META-INF/MANIFEST.MF
com.ibm.wala.ide.jdt.test/META-INF/MANIFEST.MF
com.ibm.wala.ide.jdt/source/com/ibm/wala/cast/java/translator/jdt/FakeExceptionTypeBinding.java
com.ibm.wala.ide.jdt/source/com/ibm/wala/ide/util/JavaEclipseProjectPath.java
com.ibm.wala.ide.jsdt.tests/META-INF/MANIFEST.MF
com.ibm.wala.ide.jsdt.tests/src/com/ibm/wala/ide/jsdt/tests/AbstractJSProjectScopeTest.java
com.ibm.wala.ide/src/com/ibm/wala/ide/util/EclipseProjectPath.java
com.ibm.wala.ide/src/com/ibm/wala/ide/util/ProgressMonitorDelegate.java
beginnings of "pointer analysis" on top of field-based analysis
com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/callgraph/fieldbased/flowgraph/FlowGraph.java
com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/callgraph/fieldbased/flowgraph/vertices/PropVertex.java
com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/callgraph/fieldbased/flowgraph/vertices/RetVertex.java
com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/callgraph/fieldbased/flowgraph/vertices/VarVertex.java
com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/callgraph/fieldbased/flowgraph/vertices/VertexFactory.java
com.ibm.wala.core/src/com/ibm/wala/ipa/callgraph/propagation/PointerAnalysis.java
com.ibm.wala.core/src/com/ibm/wala/ipa/callgraph/propagation/cfa/ExceptionReturnValueKey.java
fixes for crashes in correlartion tracking
com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/ipa/callgraph/correlations/extraction/ClosureExtractor.java
fixes for Dalvik IR generation
com.ibm.wala.core/src/com/ibm/wala/cfg/BytecodeCFG.java
com.ibm.wala.core/src/com/ibm/wala/cfg/ShrikeCFG.java
com.ibm.wala.core/src/com/ibm/wala/ssa/SSACFG.java
com.ibm.wala.dalvik.test/source/com/ibm/wala/dalvik/drivers/APKCallGraphDriver.java
com.ibm.wala.dalvik.test/source/com/ibm/wala/dalvik/test/callGraph/JVMLDalvikComparison.java
com.ibm.wala.dalvik/src/com/ibm/wala/dalvik/classLoader/DexCFG.java
com.ibm.wala.dalvik/src/com/ibm/wala/dalvik/dex/instructions/UnaryOperation.java
com.ibm.wala.dalvik/src/com/ibm/wala/dalvik/ssa/AbstractIntRegisterMachine.java
com.ibm.wala.dalvik/src/com/ibm/wala/dalvik/ssa/DexSSABuilder.java
fixes to stack map generation when instrumenting for Java 7
com.ibm.wala.shrike/src/com/ibm/wala/shrike/cg/DynamicCallGraph.java
com.ibm.wala.shrike/src/com/ibm/wala/shrikeBT/ConstantInstruction.java
com.ibm.wala.shrike/src/com/ibm/wala/shrikeBT/analysis/Analyzer.java
com.ibm.wala.shrike/src/com/ibm/wala/shrikeBT/analysis/ClassHierarchy.java
com.ibm.wala.shrike/src/com/ibm/wala/shrikeBT/analysis/Verifier.java
com.ibm.wala.shrike/src/com/ibm/wala/shrikeBT/shrikeCT/ClassInstrumenter.java
com.ibm.wala.shrike/src/com/ibm/wala/shrikeCT/StackMapConstants.java
com.ibm.wala.shrike/src/com/ibm/wala/shrikeCT/StackMapTableReader.java
com.ibm.wala.shrike/src/com/ibm/wala/shrikeCT/StackMapTableWriter.java
Removing this dependence allows our Getting Started instructions to still work.
It requires some minor code duplication, but otherwise we'd have to change a
bunch of documentation.
1: get the right position for methods from the JDT AST
2: more seriously, there was a nasty bug in how source positions got
mapped in unwound code: mappings were wrong for instructions that
were the result of duplicating code to replicate unwind handling in
exceptional and non-local exits.
Ben Liblit
Julian Dolby
Julian Dolby
Manu Sridharan
Michael Heilmann
Manu Sridharan