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/PrimitiveInstanceOfErrors.java

@@ -0,0 +1,27 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8304487
+ * @summary Compiler Implementation for Primitive types in patterns, instanceof, and switch (Preview)
+ * @enablePreview
+ * @compile/fail/ref=PrimitiveInstanceOfErrors.out -XDrawDiagnostics -XDshould-stop.at=FLOW PrimitiveInstanceOfErrors.java
+ */
+public class PrimitiveInstanceOfErrors {
+    public static boolean unboxingAndNarrowingPrimitiveNotAllowedPerCastingConversion() {
+        Long l_within_int_range = 42L;
+        Long l_outside_int_range = 999999999999999999L;
+
+        return l_within_int_range instanceof int && !(l_outside_int_range instanceof int);
+    }
+
+    public static <T extends Integer> boolean wideningReferenceConversionUnboxingAndNarrowingPrimitive(T i) {
+        return i instanceof byte;
+    }
+
+    public static void boxingConversionsBetweenIncompatibleTypes() {
+        int i = 42;
+
+        boolean ret1 = i instanceof Integer; // (Integer) i // OK and true
+        boolean ret2 = i instanceof Double;  // error: incompatible types
+        boolean ret3 = i instanceof Short;   // error: incompatible types
+    }
+}