undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/langtools/tools/javac/patterns/UnnamedErrors.java

@@ -0,0 +1,128 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8304246 8309093
+ * @summary Compiler Implementation for Unnamed patterns and variables
+ * @compile/fail/ref=UnnamedErrors.out -XDrawDiagnostics -XDshould-stop.at=FLOW UnnamedErrors.java
+ */
+public class UnnamedErrors {
+    private int _; // error
+    private int _, x;  // error
+    private int x, _, y, _, z, _;  // error
+    private int _ = 0, _ = 1; // error
+    private int a = 0, _ = 1; // error
+
+    record R(int _) {} //no record components
+    UnnamedErrors(int _) {} //no constructor parameters
+    void test(int _) {} //no method parameters
+
+    record RR(int x) {}
+    void test2() {
+        Object o = Integer.valueOf(42);
+        if (o instanceof _) {} //no top level
+
+        if (o instanceof _(int x)) {} //no record pattern head
+
+        switch (o) {
+            case _:
+                System.out.println("no underscore top level");
+            default:
+                System.out.println("");
+        }
+
+        switch (o) {
+            case var _:
+                System.out.println("no var _ top level");
+            default:
+                System.out.println("");
+        }
+    }
+
+    void dominanceError(Object o) {
+        switch (o) {
+            case Number _ ->
+                    System.out.println("A Number");
+            case Integer _, String _ ->             // Error - dominated case pattern: `Integer _`
+                    System.out.println("An Integer or a String");
+            default ->
+                    System.out.println("rest");
+        }
+    }
+
+    void mixedNamedUnnamedError(Object o) {
+        switch (o) {
+            case Integer i, String _ ->
+                    System.out.println("named/unnamed");
+            default ->
+                    System.out.println("rest");
+        }
+
+        switch (o) {
+            case Integer _, String s ->
+                    System.out.println("unnamed/named");
+            default ->
+                    System.out.println("rest");
+        }
+
+        switch (o) {
+            case PairIS(_, _), String s ->
+                    System.out.println("unnamed patterns/named");
+            default ->
+                    System.out.println("rest");
+        }
+    }
+
+    private void test1() {
+        try (Lock _ = null) {
+        } catch (_) { }
+    }
+
+    int guardErrors(Object o, int x1, int x2) {
+        return switch (o) {
+            case Integer _ when x1 == 2, String _ when x2 == 1 -> 1;
+            default -> 2;
+        };
+    }
+
+    int testMixVarWithExplicitDominanceError(Box<?> t) {
+        int success = -1;
+        success = switch(t) {
+            case Box(var _), Box(R2 _) : {
+                yield 1;
+            }
+            default : {
+                yield -2;
+            }
+        };
+        return success;
+    }
+
+    void testUnderscoreWithoutInitializer() {
+        int _;
+        int x1 = 1, _, x2;
+
+        for (int x = 1, _; x<=1; x++) {
+
+        }
+    }
+
+    void testUnderscoreWithBrackets() {
+        int _[] = new int[]{1};
+        for (int _[] : new int[][]{new int[]{1}, new int[]{2}}) { }
+    }
+
+    void testUnderscoreInExpression() {
+        for(String s : _) {
+            int i = 1;
+        }
+    }
+
+    class Lock implements AutoCloseable {
+        @Override
+        public void close() {}
+    }
+    record PairIS(int i, String s) {}
+    sealed abstract class Base permits R1, R2 { }
+    final  class R1  extends Base { }
+    final  class R2  extends Base { }
+    record Box<T extends Base>(T content) { }
+}