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.
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.
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.
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.
Previously some of these were accessing such fields through a subclass
of the declaring class. That creates an unnecessary extra inter-class
dependency lower in the type hierarchy than necessary.
Also, suppress this warning in an automated test input where the
indirect static accesses are explicitly intentional.
Julian Dolby
Ben Liblit
Brian Pfretzschner