Merge pull request #14 from sinha108/main

Computation of cyclomatic complexity for callables

Author: rahlk

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

@@ -112,12 +112,7 @@ private static void analyze() throws IOException, ClassHierarchyException, CallG
             gson.toJson(symbolTableExtractionResult.getRight(), new FileWriter(new File(outputPath.toString(), "parse_errors.json")));
         }
 
-        // Convert the JavaCompilationUnit to JSON
-        String symbolTableJSONString = gson.toJson(symbolTable);
-        JsonElement symbolTableJSON = gson.fromJson(symbolTableJSONString, JsonElement.class);
-
         JsonObject combinedJsonObject = new JsonObject();
-        combinedJsonObject.add("symbol_table", symbolTableJSON);
         if (analysisLevel > 1) {
             // Save SDG, IPCFG, and Call graph as JSON
             // If noBuild is not true, and build is also not provided, we will use "auto" as the build command
@@ -138,6 +133,12 @@ private static void analyze() throws IOException, ClassHierarchyException, CallG
              combinedJsonObject.add("system_dependency_graph", edges);
 
         }
+
+        // Convert the JavaCompilationUnit to JSON and add to consolidated json object
+        String symbolTableJSONString = gson.toJson(symbolTable);
+        JsonElement symbolTableJSON = gson.fromJson(symbolTableJSONString, JsonElement.class);
+        combinedJsonObject.add("symbol_table", symbolTableJSON);
+
         String consolidatedJSONString = gson.toJson(combinedJsonObject);
         emit(consolidatedJSONString);
     }

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

@@ -13,14 +13,18 @@
 
 package com.ibm.northstar;
 
+import com.ibm.northstar.entities.AbstractGraphEdge;
+import com.ibm.northstar.entities.CallEdge;
+import com.ibm.northstar.entities.Callable;
+import com.ibm.northstar.entities.SystemDepEdge;
 import com.ibm.northstar.utils.AnalysisUtils;
 import com.ibm.northstar.utils.Log;
-import com.ibm.northstar.entities.*;
 import com.ibm.northstar.utils.ScopeUtils;
 import com.ibm.wala.cast.ir.ssa.AstIRFactory;
-import com.ibm.wala.cast.java.client.impl.ZeroCFABuilderFactory;
 import com.ibm.wala.cast.java.translator.jdt.ecj.ECJClassLoaderFactory;
 import com.ibm.wala.classLoader.CallSiteReference;
+import com.ibm.wala.classLoader.IClass;
+import com.ibm.wala.classLoader.IMethod;
 import com.ibm.wala.ipa.callgraph.*;
 import com.ibm.wala.ipa.callgraph.AnalysisOptions.ReflectionOptions;
 import com.ibm.wala.ipa.callgraph.impl.Util;
@@ -51,8 +55,7 @@
 import java.util.function.Supplier;
 
 import static com.ibm.northstar.CodeAnalyzer.gson;
-import static com.ibm.northstar.utils.AnalysisUtils.getCallableFromSymbolTable;
-import static com.ibm.northstar.utils.AnalysisUtils.createAndPutNewCallableInSymbolTable;
+import static com.ibm.northstar.utils.AnalysisUtils.*;
 
 /**
  * The type Sdg 2 json.
@@ -223,6 +226,18 @@ public static String construct(
         IAnalysisCacheView cache = new AnalysisCacheImpl(AstIRFactory.makeDefaultFactory(),
                 options.getSSAOptions());
 
+        // set cyclomatic complexity for callables in the symbol table
+        int numClasses = cha.getNumberOfClasses();
+        for (Iterator<IClass> classIter = cha.iterator(); classIter.hasNext(); ) {
+            IClass cls = classIter.next();
+            for (IMethod method: cls.getAllMethods()) {
+                Callable callable = getCallableFromSymbolTable(method).getRight();
+                if (callable != null) {
+                    callable.setCyclomaticComplexity(getCyclomaticComplexity(cache.getIR(method)));
+                }
+            }
+        }
+
         // Build call graph
         Log.info("Building call graph.");
 

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

@@ -24,4 +24,5 @@ public class Callable {
     private List<String> calledMethodDeclaringTypes;
     private List<CallSite> callSites;
     private List<VariableDeclaration> variableDeclarations;
+    private int cyclomaticComplexity;
 }

src/main/java/com/ibm/northstar/utils/AnalysisUtils.java

@@ -22,6 +22,8 @@
 import com.ibm.wala.ipa.callgraph.Entrypoint;
 import com.ibm.wala.ipa.callgraph.impl.DefaultEntrypoint;
 import com.ibm.wala.ipa.cha.IClassHierarchy;
+import com.ibm.wala.ssa.IR;
+import com.ibm.wala.ssa.SSAConditionalBranchInstruction;
 import com.ibm.wala.types.ClassLoaderReference;
 
 import java.util.*;
@@ -77,6 +79,19 @@ public static Pair<String, Callable> createAndPutNewCallableInSymbolTable(IMetho
         return Pair.of(declaringClassSignature, newCallable);
     }
 
+    /**
+     * Computes and returns cyclomatic complexity for the given IR (for a method or constructor).
+     *
+     * @param ir IR for method or constructor
+     * @return int Cyclomatic complexity for method/constructor
+     */
+    public static int getCyclomaticComplexity(IR ir) {
+        int branchCount = (int)Arrays.stream(ir.getInstructions())
+            .filter(inst -> inst instanceof SSAConditionalBranchInstruction)
+            .count();
+        return branchCount + 1;
+    }
+
     public static Pair<String, Callable> getCallableFromSymbolTable(IMethod method) {
 
         // Get the class name, with a . representation.