[Soot-list] Why Spark can't obtain the call graph on this snippet? But CHA can work.

[liuyuan at fastmail.com]

Hi all,

I customizd an entry point for a library (i.e. JCommander, a command interface tool for java) and used the Spark to build its CG. But The callgraph is empty. If I use the CHA, it works. 

The code snippet is as follows and the parseWithoutValidation is selected as the entry point.
public void parseWithoutValidation(String... args) { // the customized entry point
     parse(false /* no validation */, args); // I think this method could be found easily by Spark~
}

private void parse(boolean validate, String... args) {
    StringBuilder sb = new StringBuilder("Parsing \"");
    sb.append(join(args).append("\"\n  with:").append(join(objects.toArray())));
    p(sb.toString());

    if (descriptions == null) createDescriptions();
    initializeDefaultValues();
    parseValues(expandArgs(args), validate);
    if (validate) validateOptions();
}

private StringBuilder join(Object[] args) {
    StringBuilder result = new StringBuilder();
    for (int i = 0; i < args.length; i++) {
        if (i > 0) result.append(" ");
        result.append(args[i]);
    }
    return result;
}
...

My core code is as follows.
Options.v().set_process_dir(Arrays.asList(classesDir));
Options.v().set_whole_program(true);
Options.v().set_no_bodies_for_excluded(true);
Options.v().set_allow_phantom_refs(true);

// set an entry point
SootClass c = Scene.v().forceResolve(entryClass, SootClass.BODIES);
c.setApplicationClass();
Scene.v().loadNecessaryClasses();
SootMethod method = c.getMethodByName(entryMethod);
List entryPoints = new ArrayList();
entryPoints.add(method);
Scene.v().setEntryPoints(entryPoints);

//set Spark 
HashMap<String, String> opt = new HashMap<String, String>();
opt.put("on-fly-cg", "true");
SparkTransformer.v().transform("", opt);
PhaseOptions.v().setPhaseOption("cg.spark", "enabled:true");

PackManager.v().runPacks();

The target java file is attached.

Any suggestions are welcome.

Best regards,
Yuan
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