Added call site information to callable

Author: sinha108

src/main/java/com/ibm/northstar/SymbolTable.java

@@ -300,6 +300,7 @@ private static Pair<String, Callable> processCallableDeclaration(CallableDeclara
 
         callableNode.setCalledMethodDeclaringTypes(getCalledMethodDeclaringTypes(body));
         callableNode.setAccessedFields(getAccessedFields(body, classFields, typeName));
+        callableNode.setCallSites(getCallSites(body));
 
         String callableSignature = (callableDecl instanceof MethodDeclaration) ? callableDecl.getSignature().asString() : callableDecl.getSignature().asString().replace(callableDecl.getSignature().getName(), "<init>");
         return Pair.of(callableSignature, callableNode);
@@ -425,6 +426,53 @@ private static List<String> getCalledMethodDeclaringTypes(Optional<BlockStmt> ca
         return new ArrayList<>(calledMethodDeclaringTypes);
     }
 
+    /**
+     * Returns information about call sites in the given callable. The information includes:
+     * the method name, the declaring type name, and types of arguments used in method call.
+     *
+     * @param callableBody callable to compute call-site information for
+     * @return list of call sites
+     */
+    private static List<CallSite> getCallSites(Optional<BlockStmt> callableBody) {
+        List<CallSite> callSites = new ArrayList<>();
+        if (callableBody.isEmpty()) {
+            return callSites;
+        }
+        for (MethodCallExpr methodCallExpr : callableBody.get().findAll(MethodCallExpr.class)) {
+            // resolve declaring type for called method
+            String declaringType = "";
+            if (methodCallExpr.getScope().isPresent()) {
+                declaringType = resolveExpression(methodCallExpr.getScope().get());
+                if (declaringType.contains(" | ")) {
+                    declaringType = declaringType.split(" \\| ")[0];
+                }
+            }
+
+            // resolve arguments of the method call to types
+            List<String> arguments = methodCallExpr.getArguments().stream()
+                .map(arg -> resolveExpression(arg)).collect(Collectors.toList());
+
+            // add a new call site object
+            CallSite callSite = new CallSite();
+            callSite.setMethodName(methodCallExpr.getNameAsString());
+            callSite.setDeclaringType(declaringType);
+            callSite.setArgumentTypes(arguments);
+            if (methodCallExpr.getRange().isPresent()) {
+                callSite.setStartLine(methodCallExpr.getRange().get().begin.line);
+                callSite.setStartColumn(methodCallExpr.getRange().get().begin.column);
+                callSite.setEndLine(methodCallExpr.getRange().get().end.line);
+                callSite.setEndColumn(methodCallExpr.getRange().get().end.column);
+            } else {
+                callSite.setStartLine(-1);
+                callSite.setStartColumn(-1);
+                callSite.setEndLine(-1);
+                callSite.setEndColumn(-1);
+            }
+            callSites.add(callSite);
+        }
+        return callSites;
+    }
+
     /**
      * Calculates type for the given expression and returns the resolved type name, or empty string if
      * exception occurs during type resolution.

src/main/java/com/ibm/northstar/entities/CallSite.java

@@ -0,0 +1,16 @@
+package com.ibm.northstar.entities;
+
+import lombok.Data;
+
+import java.util.List;
+
+@Data
+public class CallSite {
+    private String methodName;
+    private String declaringType;
+    private List<String> argumentTypes;
+    private int startLine;
+    private int startColumn;
+    private int endLine;
+    private int endColumn;
+}

src/main/java/com/ibm/northstar/entities/Callable.java

@@ -22,4 +22,5 @@ public class Callable {
     private List<String> referencedTypes;
     private List<String> accessedFields;
     private List<String> calledMethodDeclaringTypes;
+    private List<CallSite> callSites;
 }