8246704: --release => \"unknown enum constant PreviewFeature$Feature.TEXT_BLOCKS\"

Use a synthetic annotation instead of inaccessible jdk.internal.PreviewFeature in ct.sym, and avoid resolving that annotation, to prevent errors being printed for the inaccessible types.

Reviewed-by: jlaskey

make/langtools/src/classes/build/tools/symbolgenerator/CreateSymbols.java

@@ -1067,10 +1067,23 @@ public class CreateSymbols {
     }
 
     private Annotation createAnnotation(List<CPInfo> constantPool, AnnotationDescription desc) {
+        String annotationType = desc.annotationType;
+
+        if (PREVIEW_FEATURE_ANNOTATION.equals(annotationType)) {
+            //the non-public PreviewFeature annotation will not be available in ct.sym,
+            //replace with purely synthetic javac-internal annotation:
+            annotationType = PREVIEW_FEATURE_ANNOTATION_INTERNAL;
+        }
+
         return new Annotation(null,
-                              addString(constantPool, desc.annotationType),
+                              addString(constantPool, annotationType),
                               createElementPairs(constantPool, desc.values));
     }
+    //where:
+        private static final String PREVIEW_FEATURE_ANNOTATION =
+                "Ljdk/internal/PreviewFeature;";
+        private static final String PREVIEW_FEATURE_ANNOTATION_INTERNAL =
+                "Ljdk/internal/PreviewFeature+Annotation;";
 
     private element_value_pair[] createElementPairs(List<CPInfo> constantPool, Map<String, Object> annotationAttributes) {
         element_value_pair[] pairs = new element_value_pair[annotationAttributes.size()];

src/jdk.compiler/share/classes/com/sun/tools/javac/code/Symtab.java

@@ -217,6 +217,7 @@ public class Symtab {
     public final Type elementTypeType;
     public final Type functionalInterfaceType;
     public final Type previewFeatureType;
+    public final Type previewFeatureInternalType;
     public final Type typeDescriptorType;
     public final Type recordType;
 
@@ -580,6 +581,7 @@ public class Symtab {
         stringConcatFactory = enterClass("java.lang.invoke.StringConcatFactory");
         functionalInterfaceType = enterClass("java.lang.FunctionalInterface");
         previewFeatureType = enterClass("jdk.internal.PreviewFeature");
+        previewFeatureInternalType = enterSyntheticAnnotation("jdk.internal.PreviewFeature+Annotation");
         typeDescriptorType = enterClass("java.lang.invoke.TypeDescriptor");
         recordType = enterClass("java.lang.Record");
 

src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/ClassReader.java

@@ -1429,6 +1429,9 @@ public class ClassReader {
                         }
                     }
                 }
+            } else if (proxy.type.tsym.flatName() == syms.previewFeatureInternalType.tsym.flatName()) {
+                sym.flags_field |= PREVIEW_API;
+                setFlagIfAttributeTrue(proxy, sym, names.essentialAPI, PREVIEW_ESSENTIAL_API);
             } else {
                 if (proxy.type.tsym == syms.annotationTargetType.tsym) {
                     target = proxy;

test/langtools/tools/javac/platform/PreviewAPIsWithRelease.java

@@ -0,0 +1,15 @@
+/**
+ * @test /nodynamiccopyright/
+ * @bug 8246704
+ * @summary Verify preview APIs are reported correctly when using --release.
+ * @compile/fail/ref=PreviewAPIsWithRelease.out -XDrawDiagnostics --release 14 PreviewAPIsWithRelease.java
+ */
+
+import com.sun.source.tree.Tree.Kind;
+
+public class PreviewAPIsWithRelease {
+    void test() {
+        "".stripIndent();
+        Kind r = Kind.RECORD;
+    }
+}

test/langtools/tools/javac/platform/PreviewAPIsWithRelease.out

@@ -0,0 +1,4 @@
+PreviewAPIsWithRelease.java:12:11: compiler.err.is.preview: stripIndent()
+PreviewAPIsWithRelease.java:13:22: compiler.warn.is.preview: RECORD
+1 error
+1 warning