Class names in Soot

[Archie Cobbs <archie@dellroad.org>]

Hi,

This is to report a problem I've seen with Soot. The problem turns out
to be my own fault, however I'd like to suggest that Soot should be
'robustified' against my stupid bug :-)

Soot happily accepts class names of the form "java/lang/Object" instead
of "java.lang.Object" when loading classes for analysis. However, there
seems to be at least one subtle bug introduced when they are used. This
test program demonstrates the problem:

    import soot.*;

    public class Test {

	public static void main(String[] args) throws Exception {
	    new Test();
	}

	public Test() {
	    Scene.v().setSootClassPath(".");
	    SootClass c = Scene.v().loadClassAndSupport(getName());
	    c.setApplicationClass();
	    SootMethod m = (SootMethod)c.getMethods().iterator().next();
	    m.retrieveActiveBody();
	}

	public String getName() {
	    //return "java.lang.Object";            // this works!
	    return "java/lang/Object";              // this doesn't!
	}
    }

The program below throws this exception:

soot.jimple.toolkits.typing.TypeException: Type Error(12)
  at java.lang.Throwable.fillInStackTrace(Native Method)
  at java.lang.Throwable.fillInStackTrace(Compiled Code)
  at java.lang.Throwable.<init>(Compiled Code)
  at java.lang.Exception.<init>(Exception.java:42)
  at soot.jimple.toolkits.typing.TypeException.<init>(TypeException.java:39)
  at soot.jimple.toolkits.typing.TypeVariable.error(TypeVariable.java:532)
  at soot.jimple.toolkits.typing.TypeNode.lca(Compiled Code)
  at soot.jimple.toolkits.typing.TypeVariable.fixApprox(Compiled Code)
  at soot.jimple.toolkits.typing.TypeVariable.computeApprox(Compiled Code)
  at soot.jimple.toolkits.typing.TypeResolver.compute_approximate_types(Compiled Code)
  at soot.jimple.toolkits.typing.TypeResolver.compute_array_depth(Compiled Code)
  at soot.jimple.toolkits.typing.TypeResolver.resolve_step_1(TypeResolver.java:259)
  at soot.jimple.toolkits.typing.TypeResolver.resolve(TypeResolver.java:181)
  at soot.jimple.toolkits.typing.TypeAssigner.internalTransform(TypeAssigner.java:59)
  at soot.BodyTransformer.transform(BodyTransformer.java:58)
  at soot.BodyTransformer.transform(BodyTransformer.java:80)
  at soot.jimple.JimpleBody.applyPhaseOptions(JimpleBody.java:118)
  at soot.coffi.CoffiMethodSource.getBody(CoffiMethodSource.java:111)
  at soot.SootMethod.getBodyFromMethodSource(SootMethod.java:89)
  at soot.SootMethod.retrieveActiveBody(SootMethod.java:311)
  at Test.<init>(Test.java:15)
  at Test.main(Test.java:7)

If you change the "java/lang/Object" to "java.lang.Object" then it works.
FYI, this is using Sun's JDK. The above program crashes SableVM:

  assertion "instruction->stack_and_local_map->stack_size >= 0" failed: file "prepare_code.c", line 1088

It's nice that Soot accepts the slash version of class names, but perhaps
it should "canonicalize" all class names passed to it. If this is not
possible, it should not accept the slash versions.

Thanks,
-Archie

__________________________________________________________________________
Archie Cobbs     *     Packet Design     *     http://www.packetdesign.com