Summary: @public Infer previously did not work correctly when a function returns the result of a skip function:
```
retUndef() {
x = undefined();
return x;
}
derefUndef() {
y = retUndef();
y.doSomething(); // Symexec_memory_error here, prevents spec inference
}
```
The problem is that angelic mode did not know to add the return value of `retUndef()` to the footprint.
This diff fixes the problem by adding return values marked with the `Aundef` attribute to the footprint.
This is done lazily (e.g., a value only gets added to the footprint when you try to deref it).
Reviewed By: @jvillard
Differential Revision: D2444929
Summary:
Added two annotations @TrueOnNull and @FalseOnNull to be used for boolean functions to specify what value is returned when the argument is null.
Added model for TextUtils.isEmpty, which corresponds to the annotation
@TrueOnNull
static boolean isEmpty(@Nullable java.lang.CharSequence s)
Summary:
System.getProperty can return null when the property is not found, and expects a non-null argument.
Add models for Infer and Eradicate to reflect that.
Summary:
Errors arising from overriding methods defined in other files were not reported, because during parallel analysis the clusters did not have access to overridden methods, so could not load their annotation.
Changed cluster generation to add location information for the methods overridden by the procedures defined in the current cluster.
Summary:
When someone runs --changed-only mode, there is a risk of corrupting the results
for future analyses. The problem is that changed-only mode does not analyze the callers of changed
procedures. If a subsequent analysis relies on the specs of one of these callers, they will be stale
and may give the wrong results. To be concrete, let's say we know `Parent.foo()` calls `Child.bar()` and we do the following rounds of analysis:
Analysis round 1: Analyze all files, including `Parent` and `Child`
Analysis round 2: Analyze `Child.bar()` only with `--changed-only flag`. `Parent.foo()` is now stale.
Analysis round 3: Add procedure `Parent.baz()` that calls `Parent.foo()`, analyze in (any) incremental mode.
The analysis will only analyze `Parent.baz()`. However, the specs for `Parent.foo()` are stale and may give us bad results for `Parent.baz()`. We want the analysis to re-analyze `Parent.baz()`, but before this diff it will not.
This diff fixes this problem by adding a `STALE` status bit to procedure summaries. In `--changed-only` mode,
the callers of a changed procedures are not re-analyzed, but their summaries are marked as stale. For both
`--changed-only` and regular incremental mode, callees of changed procedures that are marked as stale are
re-analyzed even if they have not changed. This is better than a more obvious solution like deleting stale
procedure summaries, since that would force the next analysis to re-analyze all stale procedures even if it
does not need the results for whatever analysis it is doing. This scheme implemented in this diff ensures
that each analysis only does the work that it needs to compute reliable results for its changed procedures.
Summary: Handler.postDelayed keeps a persistent reference to its Runnable argument that may cause a memory leak if an Activity is reachable from the Runnable.
Summary: The Nullable checker reported FP's when a Nullable field/param was reassigned to a non-Nullable value in the footprint. This diff fixes the problem.
Summary:
This test was actually testing: "at least one Field not initialized error is found" where we actualy want to test "exactly one Field not initialized error is found". The case of @Inject was also missing from the tests.
Summary:
When detecting a resource leak, Infer used to raise an Leak exception and then prevent the specs to be computed for the paths containing a leak. This diff prevents resource leak to stop the analysis.
Summary:
Creating a persistent reference to an Activity leads to a nasty form of memory leaks (see http://android-developers.blogspot.com/2009/01/avoiding-memory-leaks.html, https://corner.squareup.com/2015/05/leak-canary.html). There are many ways to create a bad persistent reference to an Activity, but the most obvious one is via a static field.
This diff implements a very simple form of Activity leak checking by inspecting postconditions to see if a subtype of Activity is reachable from a static field (and it reports an error if so). This is a very simple and limited form of leak checking that does not understand the Android lifecycle at all. In particular, if one creates a persistent reference to an Activity and then nulls it out in `onDestroy` (a reasonably common pattern), this approach will wrongly report a bug.
Summary:
@public
Using InferBuiltins.assume previously caused an assertion failure in the analyzer. Fixed this, and fixed the implementation of the assume builtin to block when the assumed condition cannot hold.
Test Plan: Added several new tests.
Summary:
@public
The models for Java no longer require to keep the original fields since we now make the union of the fields from the models and the fields from the code to analyze.
Test Plan: Infer CI. No functional change intended.
Sam Blackshear
Cristiano Calcagno
jrm
Jules Villard
Open Source Synchronization