Handling interfaces

src/main/java/org/checkerframework/specimin/PrunerVisitor.java

@@ -3,6 +3,7 @@
 import com.github.javaparser.StaticJavaParser;
 import com.github.javaparser.ast.ImportDeclaration;
 import com.github.javaparser.ast.Node;
+import com.github.javaparser.ast.NodeList;
 import com.github.javaparser.ast.body.ClassOrInterfaceDeclaration;
 import com.github.javaparser.ast.body.ConstructorDeclaration;
 import com.github.javaparser.ast.body.FieldDeclaration;
@@ -16,6 +17,7 @@
 import com.github.javaparser.ast.expr.IntegerLiteralExpr;
 import com.github.javaparser.ast.expr.LongLiteralExpr;
 import com.github.javaparser.ast.expr.NullLiteralExpr;
+import com.github.javaparser.ast.type.ClassOrInterfaceType;
 import com.github.javaparser.ast.type.PrimitiveType;
 import com.github.javaparser.ast.type.Type;
 import com.github.javaparser.ast.visitor.ModifierVisitor;
@@ -55,6 +57,9 @@ public class PrunerVisitor extends ModifierVisitor<Void> {
    */
   private Set<String> classesUsedByTargetMethods;
 
+  /** This is to check whether the current compilation unit is a class or an interface. */
+  private boolean isInsideAnInterface = false;
+
   /**
    * This boolean tracks whether the element currently being visited is inside a target method. It
    * is set by {@link #visit(MethodDeclaration, Void)}.
@@ -101,6 +106,24 @@ public Visitable visit(ClassOrInterfaceDeclaration decl, Void p) {
       decl.remove();
       return decl;
     }
+    if (decl.isInterface()) {
+      this.isInsideAnInterface = true;
+    } else {
+      NodeList<ClassOrInterfaceType> implementedInterfaces = decl.getImplementedTypes();
+      Iterator<ClassOrInterfaceType> iterator = implementedInterfaces.iterator();
+      while (iterator.hasNext()) {
+        ClassOrInterfaceType interfaceType = iterator.next();
+        try {
+          String typeFullName = interfaceType.resolve().getQualifiedName();
+          if (!classesUsedByTargetMethods.contains(typeFullName)) {
+            iterator.remove();
+          }
+        } catch (UnsolvedSymbolException e) {
+          iterator.remove();
+        }
+      }
+      decl.setImplementedTypes(implementedInterfaces);
+    }
     return super.visit(decl, p);
   }
 
@@ -129,7 +152,9 @@ public Visitable visit(MethodDeclaration methodDecl, Void p) {
       insideTargetMethod = false;
       return result;
     } else if (membersToEmpty.contains(resolved.getQualifiedSignature())) {
-      methodDecl.setBody(StaticJavaParser.parseBlock("{ throw new Error(); }"));
+      if (!isInsideAnInterface) {
+        methodDecl.setBody(StaticJavaParser.parseBlock("{ throw new Error(); }"));
+      }
       return methodDecl;
     } else {
       // if insideTargetMethod is true, this current method declaration belongs to an anonnymous

src/main/java/org/checkerframework/specimin/SpeciminRunner.java

@@ -142,6 +142,9 @@ public static void performMinimization(
       for (String targetFile : targetFiles) {
         parsedTargetFiles.put(targetFile, parseJavaFile(root, targetFile));
       }
+      for (String targetFile : addMissingClass.getAddedTargetFiles()) {
+        parsedTargetFiles.put(targetFile, parseJavaFile(root, targetFile));
+      }
     }
 
     for (CompilationUnit cu : parsedTargetFiles.values()) {

src/main/java/org/checkerframework/specimin/TargetMethodFinderVisitor.java

@@ -95,6 +95,13 @@ public class TargetMethodFinderVisitor extends ModifierVisitor<Void> {
    */
   private final Map<String, String> importedClassToPackage;
 
+  /**
+   * This map connects the resolved declaration of a method to the interface that contains it, if
+   * any.
+   */
+  private final Map<ResolvedMethodDeclaration, ClassOrInterfaceType>
+      methodDeclarationToInterfaceType = new HashMap<>();
+
   /**
    * Create a new target method finding visitor.
    *
@@ -149,6 +156,20 @@ public Set<String> getTargetMethods() {
     return targetMethods;
   }
 
+  /**
+   * Updates the mapping of method declarations to their corresponding interface type based on a
+   * list of methods and the interface type that contains those methods.
+   *
+   * @param methodList the list of resolved method declarations
+   * @param interfaceType the interface containing the specified methods.
+   */
+  private void updateMethodDeclarationToInterfaceType(
+      List<ResolvedMethodDeclaration> methodList, ClassOrInterfaceType interfaceType) {
+    for (ResolvedMethodDeclaration method : methodList) {
+      this.methodDeclarationToInterfaceType.put(method, interfaceType);
+    }
+  }
+
   @Override
   public Node visit(ImportDeclaration decl, Void p) {
     String classFullName = decl.getNameAsString();
@@ -163,6 +184,15 @@ public Node visit(ImportDeclaration decl, Void p) {
 
   @Override
   public Visitable visit(ClassOrInterfaceDeclaration decl, Void p) {
+    for (ClassOrInterfaceType interfaceType : decl.getImplementedTypes()) {
+      try {
+        updateMethodDeclarationToInterfaceType(
+            interfaceType.resolve().getAllMethods(), interfaceType);
+      } catch (UnsolvedSymbolException e) {
+        continue;
+      }
+    }
+
     if (decl.isNestedType()) {
       this.classFQName += "." + decl.getName().toString();
     } else {
@@ -226,12 +256,13 @@ public Visitable visit(MethodDeclaration method, Void p) {
     }
 
     if (this.targetMethodNames.contains(methodName)) {
+      ResolvedMethodDeclaration resolvedMethod = method.resolve();
+      updateUsedClassesForInterface(resolvedMethod);
       updateUsedClassWithQualifiedClassName(
-          method.resolve().getPackageName() + "." + method.resolve().getClassName());
+          method.resolve().getPackageName() + "." + resolvedMethod.getClassName());
       insideTargetMethod = true;
-      targetMethods.add(method.resolve().getQualifiedSignature());
+      targetMethods.add(resolvedMethod.getQualifiedSignature());
       unfoundMethods.remove(methodName);
-      ResolvedMethodDeclaration resolvedMethod = method.resolve();
       usedClass.add(resolvedMethod.getPackageName() + "." + resolvedMethod.getClassName());
       Type returnType = method.getType();
       // JavaParser may misinterpret unresolved array types as reference types.
@@ -430,6 +461,30 @@ public Visitable visit(NameExpr expr, Void p) {
     return super.visit(expr, p);
   }
 
+  /**
+   * Updates the list of used classes based on a resolved method declaration. If the input method
+   * originates from an interface, that interface will be added to the list of used classes. The
+   * determination of whether a method belongs to an interface is based on three criteria: method
+   * name, method return type, and the number of parameters.
+   *
+   * @param method The resolved method declaration to be used for updating the list.
+   */
+  public void updateUsedClassesForInterface(ResolvedMethodDeclaration method) {
+    for (ResolvedMethodDeclaration interfaceMethod : methodDeclarationToInterfaceType.keySet()) {
+      if (method.getName().equals(interfaceMethod.getName())) {
+        String methodReturnType = method.getReturnType().describe();
+        String interfaceMethodReturnType = interfaceMethod.getReturnType().describe();
+        if (methodReturnType.equals(interfaceMethodReturnType)) {
+          if (method.getNumberOfParams() == interfaceMethod.getNumberOfParams()) {
+            usedClass.add(
+                methodDeclarationToInterfaceType.get(interfaceMethod).resolve().getQualifiedName());
+            usedMembers.add(interfaceMethod.getQualifiedSignature());
+          }
+        }
+      }
+    }
+  }
+
   /**
    * Given a method declaration, this method return the declaration of that method without the
    * return type.

src/main/java/org/checkerframework/specimin/UnsolvedSymbolVisitor.java

@@ -172,6 +172,9 @@ public class UnsolvedSymbolVisitor extends ModifierVisitor<Void> {
    */
   private final Map<String, @FullyQualifiedName String> staticImportedMembersMap = new HashMap<>();
 
+  /** New files that should be added to the list of target files for the next iteration. */
+  private final Set<String> addedTargetFiles = new HashSet<>();
+
   /**
    * Create a new UnsolvedSymbolVisitor instance
    *
@@ -281,6 +284,15 @@ public void setExceptionToFalse() {
     gotException = false;
   }
 
+  /**
+   * Get the set of target files that should be added for the next iteration.
+   *
+   * @return the value of addedTargetFiles.
+   */
+  public Set<String> getAddedTargetFiles() {
+    return addedTargetFiles;
+  }
+
   @Override
   public Node visit(ImportDeclaration decl, Void arg) {
     if (decl.isAsterisk()) {
@@ -319,6 +331,30 @@ public Visitable visit(ClassOrInterfaceDeclaration node, Void arg) {
     addTypeVariableScope(node.getTypeParameters());
     Visitable result = super.visit(node, arg);
     typeVariables.removeFirst();
+
+    NodeList<ClassOrInterfaceType> interfaceList = node.getImplementedTypes();
+    for (ClassOrInterfaceType interfaceType : interfaceList) {
+      String qualifiedName =
+          classAndPackageMap.getOrDefault(className, this.currentPackage)
+              + "."
+              + interfaceType.getName().asString();
+      if (classfileIsInOriginalCodebase(qualifiedName)) {
+        // add the source codes of the interface to the list of target files so that
+        // UnsolvedSymbolVisitor can solve symbols for that interface if needed.
+        String filePath = qualifiedName.replace(".", "/");
+        if (filePath.contains("<")) {
+          filePath = filePath.substring(filePath.indexOf("<"));
+        }
+        filePath = filePath + ".java";
+        if (!addedTargetFiles.contains(filePath)) {
+          // strictly speaking, there is no exception here. But we set gotException to true so that
+          // UnsolvedSymbolVisitor will run at least one more iteration to visit the newly added
+          // file.
+          this.gotException = true;
+        }
+        addedTargetFiles.add(filePath);
+      }
+    }
     return result;
   }
 

src/test/java/org/checkerframework/specimin/InterfaceImplementedTest.java

@@ -0,0 +1,15 @@
+package org.checkerframework.specimin;
+
+import java.io.IOException;
+import org.junit.Test;
+
+/** This test checks if Specimin can properly remove unused method signatures from an interface. */
+public class InterfaceImplementedTest {
+  @Test
+  public void runTest() throws IOException {
+    SpeciminTestExecutor.runTestWithoutJarPaths(
+        "interfaceimplemented",
+        new String[] {"com/example/Foo.java"},
+        new String[] {"com.example.Foo#doSomething()"});
+  }
+}

src/test/java/org/checkerframework/specimin/InterfaceMethodWithUnsolvedTypeTest.java

@@ -0,0 +1,18 @@
+package org.checkerframework.specimin;
+
+import java.io.IOException;
+import org.junit.Test;
+
+/**
+ * This test makes sure that Specimin will not crash if methods from interfaces have unsolved return
+ * types.
+ */
+public class InterfaceMethodWithUnsolvedTypeTest {
+  @Test
+  public void runTest() throws IOException {
+    SpeciminTestExecutor.runTestWithoutJarPaths(
+        "interfacemethodwithunsolvedtype",
+        new String[] {"com/example/Foo.java"},
+        new String[] {"com.example.Foo#doSomething(String)"});
+  }
+}

src/test/java/org/checkerframework/specimin/InterfaceWithGenericTypeTest.java

@@ -0,0 +1,15 @@
+package org.checkerframework.specimin;
+
+import java.io.IOException;
+import org.junit.Test;
+
+/** This test checks if Specimin can work for interfaces with generic types. */
+public class InterfaceWithGenericTypeTest {
+  @Test
+  public void runTest() throws IOException {
+    SpeciminTestExecutor.runTestWithoutJarPaths(
+        "interfacewithgenerictype",
+        new String[] {"com/example/Foo.java"},
+        new String[] {"com.example.Foo#doSomething(String)"});
+  }
+}

src/test/java/org/checkerframework/specimin/InterfaceWithUnsolvedSymbols.java

@@ -0,0 +1,15 @@
+package org.checkerframework.specimin;
+
+import java.io.IOException;
+import org.junit.Test;
+
+/** This test makes sure that Specimin will not crash if an interface contains unsolved symbols. */
+public class InterfaceWithUnsolvedSymbols {
+  @Test
+  public void runTest() throws IOException {
+    SpeciminTestExecutor.runTestWithoutJarPaths(
+        "interfacewithunsolvedsymbols",
+        new String[] {"com/example/Foo.java"},
+        new String[] {"com.example.Foo#doSomething(String)"});
+  }
+}

src/test/java/org/checkerframework/specimin/UnsolvedInterfaceTest.java

@@ -0,0 +1,15 @@
+package org.checkerframework.specimin;
+
+import java.io.IOException;
+import org.junit.Test;
+
+/** This test checks if Specimin can properly remove an unsolved interface. */
+public class UnsolvedInterfaceTest {
+  @Test
+  public void runTest() throws IOException {
+    SpeciminTestExecutor.runTestWithoutJarPaths(
+        "unsolvedinterface",
+        new String[] {"com/example/Foo.java"},
+        new String[] {"com.example.Foo#doManyThing()"});
+  }
+}

src/test/java/org/checkerframework/specimin/UnusedInterfaceTest.java

@@ -0,0 +1,15 @@
+package org.checkerframework.specimin;
+
+import java.io.IOException;
+import org.junit.Test;
+
+/** This test checks if Specimin can properly remove unused interfaces. */
+public class UnusedInterfaceTest {
+  @Test
+  public void runTest() throws IOException {
+    SpeciminTestExecutor.runTestWithoutJarPaths(
+        "unusedinterface",
+        new String[] {"com/example/Foo.java"},
+        new String[] {"com.example.Foo#doManyThing()"});
+  }
+}

src/test/resources/interfaceimplemented/expected/com/example/Baz.java

@@ -0,0 +1,6 @@
+package com.example;
+
+public interface Baz {
+
+    void doSomething();
+}

src/test/resources/interfaceimplemented/expected/com/example/Foo.java

@@ -0,0 +1,9 @@
+package com.example;
+
+class Foo implements Baz {
+
+    @Override
+    public void doSomething() {
+        System.out.println("Foo is doing something!");
+    }
+}

src/test/resources/interfaceimplemented/input/com/example/Baz.java

@@ -0,0 +1,9 @@
+package com.example;
+
+// Baz.java
+public interface Baz {
+    void doSomething();
+    void doOneThing();
+    void doNothing();
+}
+

src/test/resources/interfaceimplemented/input/com/example/Foo.java

@@ -0,0 +1,10 @@
+package com.example;
+
+// Foo.java
+class Foo implements Baz {
+    @Override
+    public void doSomething() {
+        System.out.println("Foo is doing something!");
+    }
+
+}

src/test/resources/interfacemethodwithunsolvedtype/expected/com/example/Baz.java

@@ -0,0 +1,8 @@
+package com.example;
+
+import org.testing.UnsolvedType;
+
+public interface Baz<T> {
+
+    UnsolvedType doSomething(T value);
+}

src/test/resources/interfacemethodwithunsolvedtype/expected/com/example/Foo.java

@@ -0,0 +1,11 @@
+package com.example;
+
+import org.testing.UnsolvedType;
+
+class Foo implements Baz<String> {
+
+    @Override
+    public UnsolvedType doSomething(String value) {
+        System.out.println("Foo is doing something with: " + value);
+    }
+}

src/test/resources/interfacemethodwithunsolvedtype/expected/org/testing/UnsolvedType.java

@@ -0,0 +1,4 @@
+package org.testing;
+
+public class UnsolvedType {
+}