1 files changed, 81 insertions, 0 deletions
diff --git a/src/main/java/com/code_intelligence/jazzer/mutation/mutator/Mutators.java b/src/main/java/com/code_intelligence/jazzer/mutation/mutator/Mutators.java
new file mode 100644
index 00000000..fcc4d7ea
--- /dev/null
+++ b/src/main/java/com/code_intelligence/jazzer/mutation/mutator/Mutators.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2023 Code Intelligence GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.code_intelligence.jazzer.mutation.mutator;
+
+import static com.code_intelligence.jazzer.mutation.support.TypeSupport.visitAnnotatedType;
+import static java.lang.String.format;
+import static java.util.Arrays.stream;
+import static java.util.stream.Collectors.joining;
+
+import com.code_intelligence.jazzer.mutation.annotation.AppliesTo;
+import com.code_intelligence.jazzer.mutation.api.ChainedMutatorFactory;
+import com.code_intelligence.jazzer.mutation.api.MutatorFactory;
+import com.code_intelligence.jazzer.mutation.mutator.collection.CollectionMutators;
+import com.code_intelligence.jazzer.mutation.mutator.lang.LangMutators;
+import com.code_intelligence.jazzer.mutation.mutator.proto.ProtoMutators;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.AnnotatedType;
+
+public final class Mutators {
+  private Mutators() {}
+
+  public static MutatorFactory newFactory() {
+    return new ChainedMutatorFactory(
+        LangMutators.newFactory(), CollectionMutators.newFactory(), ProtoMutators.newFactory());
+  }
+
+  /**
+   * Throws an exception if any annotation on {@code type} violates the restrictions of its
+   * {@link AppliesTo} meta-annotation.
+   */
+  public static void validateAnnotationUsage(AnnotatedType type) {
+    visitAnnotatedType(type, (clazz, annotations) -> {
+      outer:
+        for (Annotation annotation : annotations) {
+          AppliesTo appliesTo = annotation.annotationType().getAnnotation(AppliesTo.class);
+          if (appliesTo == null) {
+            continue;
+          }
+          for (Class<?> allowedClass : appliesTo.value()) {
+            if (allowedClass == clazz) {
+              continue outer;
+            }
+          }
+          for (Class<?> allowedSuperClass : appliesTo.subClassesOf()) {
+            if (allowedSuperClass.isAssignableFrom(clazz)) {
+              continue outer;
+            }
+          }
+
+          String helpText = "";
+          if (appliesTo.value().length != 0) {
+            helpText = stream(appliesTo.value()).map(Class::getName).collect(joining(", "));
+          }
+          if (appliesTo.subClassesOf().length != 0) {
+            if (!helpText.isEmpty()) {
+              helpText += "as well as ";
+            }
+            helpText += "subclasses of ";
+            helpText += stream(appliesTo.subClassesOf()).map(Class::getName).collect(joining(", "));
+          }
+          // Use the simple name as our annotations live in a single package.
+          throw new IllegalArgumentException(format("%s does not apply to %s, only applies to %s",
+              annotation.annotationType().getSimpleName(), clazz.getName(), helpText));
+        }
+    });
+  }
+}