[GR-43927] Expose call tree roots from CallTreePrinter

PullRequest: graal/18674

Author: rudsberg

substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/meta/AnalysisUniverse.java

@@ -563,6 +563,29 @@ public AnalysisMethod getMethod(ResolvedJavaMethod resolvedJavaMethod) {
         return methods.get(resolvedJavaMethod);
     }
 
+    /**
+     * Returns the root {@link AnalysisMethod}s. Accessing the roots is useful when traversing the
+     * call graph.
+     *
+     * @param universe the universe from which the roots are derived from.
+     * @return the call tree roots.
+     */
+    public static List<AnalysisMethod> getCallTreeRoots(AnalysisUniverse universe) {
+        List<AnalysisMethod> roots = new ArrayList<>();
+        for (AnalysisMethod m : universe.getMethods()) {
+            if (m.isDirectRootMethod() && m.isSimplyImplementationInvoked()) {
+                roots.add(m);
+            }
+            if (m.isVirtualRootMethod()) {
+                for (AnalysisMethod impl : m.collectMethodImplementations(false)) {
+                    AnalysisError.guarantee(impl.isImplementationInvoked());
+                    roots.add(impl);
+                }
+            }
+        }
+        return roots;
+    }
+
     public Map<Constant, Object> getEmbeddedRoots() {
         return embeddedRoots;
     }

substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/reports/CallTreePrinter.java

@@ -57,6 +57,7 @@
 import com.oracle.graal.pointsto.BigBang;
 import com.oracle.graal.pointsto.meta.AnalysisMethod;
 import com.oracle.graal.pointsto.meta.AnalysisType;
+import com.oracle.graal.pointsto.meta.AnalysisUniverse;
 import com.oracle.graal.pointsto.meta.InvokeInfo;
 import com.oracle.graal.pointsto.meta.PointsToAnalysisMethod;
 import com.oracle.graal.pointsto.util.AnalysisError;
@@ -182,18 +183,7 @@ public CallTreePrinter(BigBang bb) {
 
     public void buildCallTree() {
         /* Add all the roots to the tree. */
-        List<AnalysisMethod> roots = new ArrayList<>();
-        for (AnalysisMethod m : bb.getUniverse().getMethods()) {
-            if (m.isDirectRootMethod() && m.isSimplyImplementationInvoked()) {
-                roots.add(m);
-            }
-            if (m.isVirtualRootMethod()) {
-                for (AnalysisMethod impl : m.collectMethodImplementations(false)) {
-                    AnalysisError.guarantee(impl.isImplementationInvoked());
-                    roots.add(impl);
-                }
-            }
-        }
+        List<AnalysisMethod> roots = AnalysisUniverse.getCallTreeRoots(bb.getUniverse());
 
         roots.sort(methodComparator);
         for (AnalysisMethod m : roots) {