[by Willem Verstraeten] dfa: support @AutoValue and other immutable annotations from ConcurrencyAnnotationsManager (IDEA-208913)

adapted from https://github.com/JetBrains/intellij-community/pull/1090

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaExpressionFactory.java

@@ -16,6 +16,7 @@
 package com.intellij.codeInspection.dataFlow.value;
 
 import com.intellij.codeInsight.AnnotationUtil;
+import com.intellij.codeInsight.ConcurrencyAnnotationsManager;
 import com.intellij.codeInsight.Nullability;
 import com.intellij.codeInspection.dataFlow.*;
 import com.intellij.codeInspection.dataFlow.rangeSet.LongRangeSet;
@@ -232,8 +233,7 @@ public class DfaExpressionFactory {
         }
       }
       if (method.getParameterList().isEmpty()) {
-        if ((JavaMethodContractUtil.isPure(method) ||
-            AnnotationUtil.findAnnotation(method.getContainingClass(), "javax.annotation.concurrent.Immutable") != null) &&
+        if ((JavaMethodContractUtil.isPure(method) || isClassAnnotatedImmutable(method)) &&
             isContractAllowedForGetter(method)) {
           return new GetterDescriptor(method);
         }
@@ -242,6 +242,11 @@ public class DfaExpressionFactory {
     return null;
   }
 
+  private static boolean isClassAnnotatedImmutable(PsiMethod method) {
+    List<String> annotations = ConcurrencyAnnotationsManager.getInstance(method.getProject()).getImmutableAnnotations();
+    return AnnotationUtil.findAnnotation(method.getContainingClass(), annotations) != null;
+  }
+
   private static boolean isContractAllowedForGetter(PsiMethod method) {
     List<? extends MethodContract> contracts = JavaMethodContractUtil.getMethodCallContracts(method, null);
     if (contracts.size() == 1) {

java/java-psi-api/src/com/intellij/codeInsight/ConcurrencyAnnotationsManager.java

@@ -17,7 +17,6 @@ package com.intellij.codeInsight;
 
 import com.intellij.openapi.components.ServiceManager;
 import com.intellij.openapi.project.Project;
-import com.intellij.util.Function;
 import com.intellij.util.containers.ContainerUtil;
 
 import java.util.ArrayList;
@@ -42,6 +41,8 @@ public class ConcurrencyAnnotationsManager {
     fillDefaults(myGuardedByList, GUARDED_BY);
     fillDefaults(myThreadSafeList, THREAD_SAFE);
     fillDefaults(myNotThreadSafeList, NOT_THREAD_SAFE);
+
+    myImmutableList.add("com.google.auto.value.AutoValue");
   }
 
   private static void fillDefaults(List<? super String> list, final String annoName) {

java/java-tests/testData/inspection/dataFlow/fixture/ImmutableClassNonGetterMethod.java

@@ -3,11 +3,21 @@ interface Intf {
   @org.jetbrains.annotations.Nullable String foo();
 }
 
+@com.google.auto.value.AutoValue
+abstract class Value {
+  abstract @org.jetbrains.annotations.Nullable String foo();
+}
+
 class Usage {
   void bar(Intf i) {
     if (i.foo() != null) {
       System.out.println(i.foo().length());
     }
   }
+  void bar(Value i) {
+    if (i.foo() != null) {
+      System.out.println(i.foo().length());
+    }
+  }
 
 }

java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspectionTest.java

@@ -278,6 +278,7 @@ public class DataFlowInspectionTest extends DataFlowInspectionTestCase {
   }
 
   public void testImmutableClassNonGetterMethod() {
+    myFixture.addClass("package com.google.auto.value; public @interface AutoValue {}");
     myFixture.addClass("package javax.annotation.concurrent; public @interface Immutable {}");
     doTest();
   }