turn off contract inference for overrideable methods; hopefully, not forever (IDEA-127518)

java/java-impl/src/com/intellij/codeInsight/InferredAnnotationsManagerImpl.java

@@ -17,17 +17,20 @@ package com.intellij.codeInsight;
 
 import com.intellij.codeInspection.bytecodeAnalysis.ProjectBytecodeAnalysis;
 import com.intellij.codeInspection.dataFlow.ContractInference;
-import com.intellij.codeInspection.dataFlow.ControlFlowAnalyzer;
 import com.intellij.codeInspection.dataFlow.MethodContract;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.PsiAnnotation;
 import com.intellij.psi.PsiMethod;
 import com.intellij.psi.PsiModifierListOwner;
+import com.intellij.psi.util.PsiUtil;
+import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
 
+import static com.intellij.codeInspection.dataFlow.ControlFlowAnalyzer.ORG_JETBRAINS_ANNOTATIONS_CONTRACT;
+
 public class InferredAnnotationsManagerImpl extends InferredAnnotationsManager {
   @Nullable
   @Override
@@ -37,7 +40,7 @@ public class InferredAnnotationsManagerImpl extends InferredAnnotationsManager {
       return fromBytecode;
     }
 
-    if (listOwner instanceof PsiMethod && ControlFlowAnalyzer.ORG_JETBRAINS_ANNOTATIONS_CONTRACT.equals(annotationFQN)) {
+    if (listOwner instanceof PsiMethod && ORG_JETBRAINS_ANNOTATIONS_CONTRACT.equals(annotationFQN) && !PsiUtil.canBeOverriden((PsiMethod)listOwner)) {
       List<MethodContract> contracts = ContractInference.inferContracts((PsiMethod)listOwner);
       if (!contracts.isEmpty()) {
         return ProjectBytecodeAnalysis.getInstance(listOwner.getProject()).createContractAnnotation("\"" + StringUtil.join(contracts, "; ") + "\"");
@@ -50,19 +53,25 @@ public class InferredAnnotationsManagerImpl extends InferredAnnotationsManager {
   @NotNull
   @Override
   public PsiAnnotation[] findInferredAnnotations(@NotNull PsiModifierListOwner listOwner) {
+    List<PsiAnnotation> result = ContainerUtil.newArrayList();
     PsiAnnotation[] fromBytecode = ProjectBytecodeAnalysis.getInstance(listOwner.getProject()).findInferredAnnotations(listOwner);
-    if (fromBytecode.length > 0) {
-      return fromBytecode;
-    }
-
-    if (listOwner instanceof PsiMethod) {
-      List<MethodContract> contracts = ContractInference.inferContracts((PsiMethod)listOwner);
-      if (!contracts.isEmpty()) {
-        return new PsiAnnotation[]{ProjectBytecodeAnalysis.getInstance(listOwner.getProject()).createContractAnnotation("\"" + StringUtil.join(contracts, "; ") + "\"")};
+    for (PsiAnnotation annotation : fromBytecode) {
+      if (!ORG_JETBRAINS_ANNOTATIONS_CONTRACT.equals(annotation.getQualifiedName()) ||
+          !(listOwner instanceof PsiMethod) ||
+          !PsiUtil.canBeOverriden((PsiMethod)listOwner)) {
+        result.add(annotation);
       }
     }
 
-    return PsiAnnotation.EMPTY_ARRAY;
+    if (listOwner instanceof PsiMethod && !PsiUtil.canBeOverriden((PsiMethod)listOwner)) {
+      List<MethodContract> contracts = ContractInference.inferContracts((PsiMethod)listOwner);
+      if (!contracts.isEmpty()) {
+        result.add(ProjectBytecodeAnalysis.getInstance(listOwner.getProject())
+                     .createContractAnnotation("\"" + StringUtil.join(contracts, "; ") + "\""));
+      }
+    }
+
+    return result.isEmpty() ? PsiAnnotation.EMPTY_ARRAY : result.toArray(new PsiAnnotation[result.size()]);
   }
 
   @Override

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

@@ -0,0 +1,21 @@
+import org.jetbrains.annotations.Nullable;
+
+class Doo {
+
+  boolean isMaybeNotNull(@Nullable Object o) {
+    return o != null;
+  }
+
+  void foo(@Nullable String s) {
+    if (isMaybeNotNull(s)) {
+      System.out.println(<warning descr="Method invocation 's.length()' may produce 'java.lang.NullPointerException'">s.length()</warning>);
+    }
+  }
+
+}
+
+class DooImpl extends Doo {
+  boolean isMaybeNotNull(@Nullable Object o) {
+    return hashCode() == 42;
+  }
+}

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

@@ -2,7 +2,7 @@ import org.jetbrains.annotations.Nullable;
 
 class Doo {
 
-  boolean isNotNull(@Nullable Object o) {
+  static boolean isNotNull(@Nullable Object o) {
     return o != null;
   }
 

java/java-tests/testSrc/com/intellij/codeInspection/ContractInferenceFromSourceTest.groovy

@@ -277,7 +277,7 @@ class ContractInferenceFromSourceTest extends LightCodeInsightFixtureTestCase {
   }
 
   private List<String> inferContracts(String method) {
-    def clazz = myFixture.addClass("class Foo { $method }")
+    def clazz = myFixture.addClass("final class Foo { $method }")
     return ContractInference.inferContracts(clazz.methods[0]).collect { it as String }
   }
 }

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

@@ -251,6 +251,7 @@ public class DataFlowInspectionTest extends LightCodeInsightFixtureTestCase {
   public void testRootThrowableCause() { doTest(); }
 
   public void testUseInferredContracts() { doTest(); }
+  public void testContractInferenceBewareOverriding() { doTest(); }
 
   public void testNumberComparisonsWhenValueIsKnown() { doTest(); }