Unexpected type: class com.ibm.wala.analysis.typeInference.JavaPrimitiveType

[vazexqi]

Here's the stack trace

Caused by: com.ibm.wala.util.debug.UnimplementedError: Unexpected type: class com.ibm.wala.analysis.typeInference.JavaPrimitiveType
    at com.ibm.wala.util.debug.Assertions.UNREACHABLE(Assertions.java:55)
    at com.ibm.wala.analysis.typeInference.PointType.meet(PointType.java:69)
    at com.ibm.wala.analysis.typeInference.TypeInference$PrimitivePropagateOperator.evaluate(TypeInference.java:392)
    at com.ibm.wala.cast.java.analysis.typeInference.AstJavaTypeInference$PrimAndStringOp.evaluate(AstJavaTypeInference.java:142)
    at com.ibm.wala.analysis.typeInference.TypeInference$PrimitivePropagateOperator.evaluate(TypeInference.java:1)
    at com.ibm.wala.fixedpoint.impl.GeneralStatement.evaluate(GeneralStatement.java:36)
    at com.ibm.wala.fixedpoint.impl.AbstractFixedPointSolver.solve(AbstractFixedPointSolver.java:149)
    at com.ibm.wala.analysis.typeInference.TypeInference.solve(TypeInference.java:126)
    at com.ibm.wala.analysis.typeInference.TypeInference.solve(TypeInference.java:117)
    at com.ibm.wala.analysis.typeInference.TypeInference.<init>(TypeInference.java:113)
    at com.ibm.wala.cast.analysis.typeInference.AstTypeInference.<init>(AstTypeInference.java:70)
    at com.ibm.wala.cast.java.analysis.typeInference.AstJavaTypeInference.<init>(AstJavaTypeInference.java:98)
    at edu.illinois.jflow.jflow.wala.dataflowanalysis.ProgramDependenceGraph.<init>(ProgramDependenceGraph.java:80)
    at edu.illinois.jflow.jflow.wala.dataflowanalysis.ProgramDependenceGraph.makeWithSourceCode(ProgramDependenceGraph.java:65)
    at edu.illinois.jflow.core.transformations.code.ExtractClosureRefactoring.createPDGAnalyzer(ExtractClosureRefactoring.java:302)

Here's the offending code:

package extractclosure;

public class Project1 {
    public static void main(String[] args) {
        int a = producer(1);
        /*[*/
        int b = producer(a);
        int c = producer(b);
        System.out.println("a: " + a + ", c: " + c); // <--- This line here, if we remove it al is well.
        /*]*/
    }

    static int producer(int input) {
        return input + 2;
    }
}

[vazexqi]

This is probably because the "a: " + a gets translated into a binaryop(add) and that confuses Wala since it is not expecting the + on a string and an integer.

[vazexqi]

I confirm this by replacing the offending line with

        int b = producer(a);
        int c = producer(b);
        System.out.println(String.format("a: %s, b: %s", a, b)); // <-- this avoid the binaryop(add) that confuses Wala

[vazexqi]

After more investigation, the culprit for this is actually

  public AstJavaTypeInference(IR ir, IClassHierarchy cha, boolean doPrimitives) {
    super(ir, cha, JavaPrimitiveType.BOOLEAN, doPrimitives);
    this.stringClass = cha.lookupClass(TypeReference.JavaLangString);
  }

The field, stringClass, is not initialized in time. That is because the call to super actually calls the call to initialize() and solve, which will cause trouble when you try to compare the types.

[vazexqi]

Reported and fixed in the latest version of WALA
wala/WALA#12
wala/WALA#13