[java-inspections] IDEA-284073 Enhance dfa: Support that Stream.toList() is unmodifiable

PR#1861

GitOrigin-RevId: ddddc2451708df8e11d00e059eafdb8674fa562b

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/Mutability.java

@@ -12,6 +12,7 @@ import com.intellij.java.analysis.JavaAnalysisBundle;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Key;
 import com.intellij.openapi.util.ModificationTracker;
+import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.*;
 import com.intellij.psi.impl.light.LightElement;
 import com.intellij.psi.impl.source.PsiMethodImpl;
@@ -64,6 +65,8 @@ public enum Mutability {
   public static final @NotNull String UNMODIFIABLE_VIEW_ANNOTATION = UNMODIFIABLE_VIEW.myAnnotation;
   private static final @NotNull CallMatcher STREAM_COLLECT = CallMatcher.instanceCall(
     CommonClassNames.JAVA_UTIL_STREAM_STREAM, "collect").parameterTypes("java.util.stream.Collector");
+  private static final @NotNull CallMatcher STREAM_TO_LIST = CallMatcher.instanceCall(
+    CommonClassNames.JAVA_UTIL_STREAM_STREAM, "toList").withLanguageLevelAtLeast(LanguageLevel.JDK_16);
   private static final @NotNull CallMatcher UNMODIFIABLE_COLLECTORS = CallMatcher.staticCall(
     CommonClassNames.JAVA_UTIL_STREAM_COLLECTORS, "toUnmodifiableList", "toUnmodifiableSet", "toUnmodifiableMap");
   private final @PropertyKey(resourceBundle = JavaAnalysisBundle.BUNDLE) String myResourceKey;
@@ -187,6 +190,8 @@ public enum Mutability {
           if (STREAM_COLLECT.test(call)) {
             PsiExpression collector = call.getArgumentList().getExpressions()[0];
             newMutability = UNMODIFIABLE_COLLECTORS.matches(collector) ? UNMODIFIABLE : UNKNOWN;
+          } else if (STREAM_TO_LIST.test(call)) {
+            newMutability = UNMODIFIABLE;
           } else {
             PsiMethod method = call.resolveMethod();
             newMutability = method == null ? UNKNOWN : getMutability(method);

java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/java/inliner/StreamChainInliner.java

@@ -28,6 +28,7 @@ import com.intellij.codeInspection.dataFlow.types.DfType;
 import com.intellij.codeInspection.dataFlow.types.DfTypes;
 import com.intellij.codeInspection.dataFlow.value.DfaVariableValue;
 import com.intellij.codeInspection.dataFlow.value.RelationType;
+import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.*;
 import com.intellij.psi.util.InheritanceUtil;
 import com.intellij.psi.util.PsiUtil;
@@ -69,6 +70,8 @@ public class StreamChainInliner implements CallInliner {
     instanceCall(JAVA_UTIL_STREAM_STREAM, "reduce").parameterTypes("T", "java.util.function.BinaryOperator");
   private static final CallMatcher COLLECT_TERMINAL =
     instanceCall(JAVA_UTIL_STREAM_STREAM, "collect").parameterTypes("java.util.stream.Collector");
+  private static final CallMatcher TO_LIST_TERMINAL = instanceCall(JAVA_UTIL_STREAM_STREAM, "toList")
+    .withLanguageLevelAtLeast(LanguageLevel.JDK_16);
   private static final CallMatcher COLLECT3_TERMINAL =
     instanceCall(JAVA_UTIL_STREAM_STREAM, "collect").parameterTypes("java.util.function.Supplier",
                                                                     "java.util.function.BiConsumer", "java.util.function.BiConsumer");
@@ -142,6 +145,7 @@ public class StreamChainInliner implements CallInliner {
     .register(TO_ARRAY_TERMINAL, call -> new ToArrayStep(call))
     .register(COLLECT3_TERMINAL, call -> new Collect3TerminalStep(call))
     .register(COLLECT_TERMINAL, call -> createTerminalFromCollector(call))
+    .register(TO_LIST_TERMINAL, call -> new ToCollectionStep(call, null, true))
     .register(TWO_ARG_REDUCE, call -> new TwoArgReduceStep(call));
 
   private static final Step NULL_TERMINAL_STEP = new Step(null, null, null) {

java/java-tests/testData/inspection/dataFlow/fixture/MutabilityJdk16.java

@@ -0,0 +1,41 @@
+package java.util.stream;
+
+import java.util.List;
+import java.util.Iterator;
+import java.util.Spliterator;
+
+//mock
+class Stream<T> implements BaseStream<T, Stream<T>>{
+  public native List<T> toList();
+
+  public native Iterator<T> iterator();
+
+  public native Spliterator<T> spliterator();
+
+  public native boolean isParallel();
+
+  public native Stream<T> sequential();
+
+  public native Stream<T> parallel();
+
+  public native Stream<T> unordered();
+
+  public native Stream<T> onClose(Runnable var1);
+
+  public native void close();
+}
+
+public class MutabilityJdk16 {
+
+  private final List<Integer> list = new Stream<Integer>().toList();
+
+  void testFieldList(){
+    list.<warning descr="Immutable object is modified">add</warning>(4);
+  }
+
+  void testToList() {
+    List<Integer> l = new Stream<Integer>()
+      .toList();
+    l.<warning descr="Immutable object is modified">add</warning>(4);
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection16Test.java

@@ -39,4 +39,6 @@ public class DataFlowInspection16Test extends DataFlowInspectionTestCase {
     doTest(); 
   }
   public void testStaticFieldInAnonymous() { doTest(); }
+
+  public void testMutabilityJdk16() { doTest(); }
 }