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.
This is the first time I can ever remember explicitly casting to
`Object`. Such a cast might seem useless, and certainly it is
statically known to always succeed. However, it is here for good
reason. Without the cast, we end up making a `Pair<Object, ?>` but
what we really want is a `Pair<Object, Object>`.
Each of these required careful consideration of what the original
developer *intended* as distinguished from what the developer's code
actually *does*. I believe I got each one right, and WALA's
regression tests agree. A second opinion by a core WALA developer
would be welcome, though.
In "com.ibm.wala.cast.test", the "cbuild.sh" script is gone entirely.
Instead, "pom.xml" directs Maven to run "make" directly. We still
have a "Makefile.configuration" file in this project, but this file is
now independent of where WALA is being built and of where Java is
installed.
In "com.ibm.wala.cast", a small "cbuild.sh" remains, to do some
special processing involving Visual Studio variables under Windows.
When not building under Windows, "cbuild.sh" now simply runs "make".
It may well be possible to hoist the special Windows stuff up into
this subproject's "pom.xml", or to change that "pom.xml" to run
"cbuild.sh" only when on Windows, and to run "make" directly
otherwise. I don't know "pom.xml" stuff very well, though. We still
have a "Makefile.configuration" file in this project, but this file is
now independent of where WALA is being built and of where Java is
installed.
The changes I've made in both "Makefile.configuration" files use GNU
make extensions. I assume that's safe because "Makefile.definitions"
already relies on GNU make.
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.
Julian Dolby
Ben Liblit
Julian Dolby
Manu Sridharan
dolby-oss