fixedInitialStore may be null

typetools · Jul 19, 2023 · c88e096 · c88e096
1 parent 355bf05
commit c88e096
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Showing 3 changed files with 33 additions and 16 deletions.
diff --git a/framework/src/main/java/org/checkerframework/framework/flow/CFAbstractTransfer.java b/framework/src/main/java/org/checkerframework/framework/flow/CFAbstractTransfer.java
@@ -22,7 +22,6 @@
 import javax.lang.model.element.VariableElement;
 import javax.lang.model.type.TypeMirror;
 import org.checkerframework.checker.interning.qual.InternedDistinct;
-import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 import org.checkerframework.checker.nullness.qual.PolyNull;
 import org.checkerframework.dataflow.analysis.ConditionalTransferResult;
@@ -215,10 +214,14 @@ protected V getValueFromFactory(Tree tree, Node node) {
   }
 
   /** The fixed initial store. */
-  private @MonotonicNonNull S fixedInitialStore = null;
+  private @Nullable S fixedInitialStore = null;
 
-  /** Set a fixed initial Store. */
-  public void setFixedInitialStore(S s) {
+  /**
+   * Set a fixed initial Store.
+   *
+   * @param s initial store; possible null
+   */
+  public void setFixedInitialStore(@Nullable S s) {
     fixedInitialStore = s;
   }
 
@@ -284,15 +287,19 @@ public S initialStore(UnderlyingAST underlyingAST, List<LocalVariableNode> param
       }
 
     } else if (underlyingAST.getKind() == UnderlyingAST.Kind.LAMBDA) {
-      // Create a copy and keep only the field values (nothing else applies).
-      store = analysis.createCopiedStore(fixedInitialStore);
-      // Allow that local variables are retained; they are effectively final,
-      // otherwise Java wouldn't allow access from within the lambda.
-      // TODO: what about the other information? Can code further down be simplified?
-      // store.localVariableValues.clear();
-      store.classValues.clear();
-      store.arrayValues.clear();
-      store.methodValues.clear();
+      if (fixedInitialStore != null) {
+        // Create a copy and keep only the field values (nothing else applies).
+        store = analysis.createCopiedStore(fixedInitialStore);
+        // Allow that local variables are retained; they are effectively final,
+        // otherwise Java wouldn't allow access from within the lambda.
+        // TODO: what about the other information? Can code further down be simplified?
+        // store.localVariableValues.clear();
+        store.classValues.clear();
+        store.arrayValues.clear();
+        store.methodValues.clear();
+      } else {
+        store = analysis.createEmptyStore(sequentialSemantics);
+      }
 
       for (LocalVariableNode p : parameters) {
         AnnotatedTypeMirror anno = atypeFactory.getAnnotatedType(p.getElement());

diff --git a/framework/src/main/java/org/checkerframework/framework/type/GenericAnnotatedTypeFactory.java b/framework/src/main/java/org/checkerframework/framework/type/GenericAnnotatedTypeFactory.java
@@ -1348,7 +1348,8 @@ protected void performFlowAnalysis(ClassTree classTree) {
       initializationStaticStore = capturedStore;
       initializationStore = capturedStore;
 
-      Queue<IPair<LambdaExpressionTree, Store>> lambdaQueue = new ArrayDeque<>();
+      // The store is null if the lambda is unreachable.
+      Queue<IPair<LambdaExpressionTree, @Nullable Store>> lambdaQueue = new ArrayDeque<>();
 
       // Queue up classes (for top-level `while` loop) and methods (for within this `try`
       // construct); analyze top-level blocks and variable initializers as they are
@@ -1455,7 +1456,7 @@ protected void performFlowAnalysis(ClassTree classTree) {
         }
 
         while (!lambdaQueue.isEmpty()) {
-          IPair<LambdaExpressionTree, Store> lambdaPair = lambdaQueue.poll();
+          IPair<LambdaExpressionTree, @Nullable Store> lambdaPair = lambdaQueue.poll();
           MethodTree mt =
               (MethodTree)
                   TreePathUtil.enclosingOfKind(getPath(lambdaPair.first), Tree.Kind.METHOD);
@@ -1526,7 +1527,7 @@ protected void analyze(
       boolean isInitializationCode,
       boolean updateInitializationStore,
       boolean isStatic,
-      Store capturedStore) {
+      @Nullable Store capturedStore) {
     ControlFlowGraph cfg = CFCFGBuilder.build(root, ast, checker, this, processingEnv);
 
     if (isInitializationCode) {

diff --git a/framework/tests/all-systems/Issue6104.java b/framework/tests/all-systems/Issue6104.java
@@ -0,0 +1,9 @@
+public class Issue6104 {
+  public void m() {
+    try {
+    } catch (Exception e) {
+      // Because the try block is empty, this lambda is unreachable.
+      Runnable r = () -> {};
+    }
+  }
+}