fixed bug in jar converter w.r.t. reading single class file (an NPE) …

…and a classpath parameter was missing for looking up parent classes in the hierarchy

src/org/rascalmpl/library/TestMe.rsc

@@ -0,0 +1,17 @@
+module TestMe
+
+import IO;
+import util::Benchmark;
+import util::Math;
+
+void main() {
+    results = for (i <- [2,3,4,5]) {
+        println("2^<i> chains");
+        append cpuTimeOf(() {
+            R = {<j, j+1> | j <- [0..toInt(pow(10,i))], j % 100 != 0};
+            R+;
+        });
+    }
+
+    iprintln(results);
+}

src/org/rascalmpl/library/lang/java/m3/Core.rsc

@@ -115,7 +115,7 @@ java M3 createM3FromString(loc fileName, str contents, bool errorRecovery = fals
 java M3 createM3FromJarClass(loc jarClass, list[loc] classPath = []);
 
 @javaClass{org.rascalmpl.library.lang.java.m3.internal.EclipseJavaCompiler}
-java M3 createM3FromSingleClass(loc jarClass, str className);
+java M3 createM3FromSingleClass(loc jarClass, str className, list[loc] classPath = []);
 
 @javaClass{org.rascalmpl.library.lang.java.m3.internal.EclipseJavaCompiler}
 java M3 createM3FromJarFile(loc jarLoc, list[loc] classPath = []);

src/org/rascalmpl/library/lang/java/m3/internal/EclipseJavaCompiler.java

@@ -67,9 +67,9 @@ public IValue createM3FromJarClass(ISourceLocation jarLoc, IList classPath) {
         return createM3FromJarClass(jarLoc, classPath, getM3Store());
     }
 
-    public IValue createM3FromSingleClass(ISourceLocation classLoc, IString className) {
+    public IValue createM3FromSingleClass(ISourceLocation classLoc, IString className, IList classpath) {
         JarConverter converter = new JarConverter(getM3Store(), new HashMap<>());
-        converter.convertJarFile(classLoc, ((IString) className).getValue());
+        converter.convertJarFile(classLoc, ((IString) className).getValue(), classpath);
         return converter.getModel(false);
     }
 

src/org/rascalmpl/library/lang/java/m3/internal/JarConverter.java

@@ -132,9 +132,9 @@ public void convertJar(ISourceLocation jar, IList classPath) {
      * @param classFile
      * @param className
      */
-    public void convertJarFile(ISourceLocation classFile, String className) {
+    public void convertJarFile(ISourceLocation classFile, String className, IList classpath) {
         loc = classFile;
-        createSingleClassM3(className);
+        createSingleClassM3(className, classpath);
     }
 
     /**
@@ -172,7 +172,11 @@ private void createM3() {
      * and parent packages is triggered.
      * @param className
      */
-    private void createSingleClassM3(String className) {
+    private void createSingleClassM3(String className, IList classpath) {
+        if (resolver == null) {
+            resolver = new ASMNodeResolver(loc, classpath, typeStore);
+        }
+
         String compUnit = className;
         ClassReader classReader = resolver.buildClassReader(className);