Summary:
One limitation of Eradicate is that certain nullability patterns are not expressible using simply the `Nullable` annotation.
One such pattern is using the knowledge that a function returns null when passed null, but returns an object otherwise.
The annotation `PropagatesNullable` is a variant of `Nullable` applied to parameters when their value propagates to the return value.
A method annotated
```
B m(PropagatesNullable A x) { return x == null ? x : B(x); }
```
indicates that `m` returns null if `x` is null, or an object of class `B` if the argument is not null.
Examples with multiple parameters are in the test cases.
This diff builds some infrastructure for annotation transformers: the example above represents the identity function on nullability annotations.
Reviewed By: jvillard
Differential Revision: D4705938
fbshipit-source-id: 9f6194e
Summary:
public
Lines other than the first of multi-line comments in non-ocaml files
were flush right instead of aligned.
Reviewed By: jvillard
Differential Revision: D2739752
fb-gh-sync-id: c85f56e
Summary:
public
It is possible to return null according to
http://docs.oracle.com/javase/7/docs/api/java/lang/Class.html#getResource(java.lang.String).
Also, getResource throws NPE if passed null:
$ cat -n TestClassGetResourceArgument.java
1 import java.net.URL;
2
3 public class TestClassGetResourceArgument {
4
5 static URL testClassGetResourceArgument(Class cls) {
6 return cls.getResource(null);
7 }
8
9 public static void main(String[] args) {
10 System.out.println(testClassGetResourceArgument("".getClass()).toString());
11 }
12
13 }
$ javac TestClassGetResourceArgument.java && java TestClassGetResourceArgument
Exception in thread "main" java.lang.NullPointerException
at sun.misc.MetaIndex.mayContain(MetaIndex.java:243)
at sun.misc.URLClassPath$JarLoader.getResource(URLClassPath.java:830)
at sun.misc.URLClassPath.getResource(URLClassPath.java:199)
at sun.misc.URLClassPath.getResource(URLClassPath.java:251)
at java.lang.ClassLoader.getBootstrapResource(ClassLoader.java:1305)
at java.lang.ClassLoader.getResource(ClassLoader.java:1144)
at java.lang.ClassLoader.getResource(ClassLoader.java:1142)
at java.lang.ClassLoader.getSystemResource(ClassLoader.java:1267)
at java.lang.Class.getResource(Class.java:2145)
at TestClassGetResourceArgument.testClassGetResourceArgument(TestClassGetResourceArgument.java:6)
at TestClassGetResourceArgument.main(TestClassGetResourceArgument.java:10)
Reviewed By: cristianoc
Differential Revision: D2752301
fb-gh-sync-id: 888baf1
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.
Cristiano Calcagno
Josh Berdine
Open Source Synchronization