8291643: Consider omitting type annotations from type error diagnostics

Reviewed-by: vromero

make/langtools/tools/propertiesparser/parser/MessageType.java

@@ -97,6 +97,7 @@ public interface MessageType {
         TOKEN("token", "TokenKind", "com.sun.tools.javac.parser.Tokens"),
         TREE_TAG("tree tag", "Tag", "com.sun.tools.javac.tree.JCTree"),
         TYPE("type", "Type", "com.sun.tools.javac.code"),
+        ANNOTATED_TYPE("annotated-type", "AnnotatedType", "com.sun.tools.javac.util.JCDiagnostic"),
         URL("url", "URL", "java.net"),
         SET("set", "Set", "java.util"),
         LIST("list", "List", "java.util"),

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

@@ -510,7 +510,7 @@ public class TypeAnnotations {
                             Fragments.TypeAnnotation1(onlyTypeAnnotations.head) :
                             Fragments.TypeAnnotation(onlyTypeAnnotations);
                     log.error(typetree.pos(), Errors.TypeAnnotationInadmissible(
-                            annotationFragment, annotated.tsym.owner, annotated));
+                            annotationFragment, annotated.tsym.owner, new JCDiagnostic.AnnotatedType(annotated)));
                     return type;
                 }
 

src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java

@@ -5868,8 +5868,10 @@ public class Attr extends JCTree.Visitor {
                             Fragment annotationFragment = onlyTypeAnnotations.size() == 1 ?
                                     Fragments.TypeAnnotation1(onlyTypeAnnotations.head) :
                                     Fragments.TypeAnnotation(onlyTypeAnnotations);
+                            JCDiagnostic.AnnotatedType annotatedType = new JCDiagnostic.AnnotatedType(
+                                    type.stripMetadata().annotatedType(onlyTypeAnnotations));
                             log.error(at.underlyingType.pos(), Errors.TypeAnnotationInadmissible(annotationFragment,
-                                    type.tsym.owner, type.stripMetadata().annotatedType(onlyTypeAnnotations)));
+                                    type.tsym.owner, annotatedType));
                         }
                         repeat = false;
                     }

src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties

@@ -3258,7 +3258,7 @@ compiler.err.this.as.identifier=\
 compiler.err.receiver.parameter.not.applicable.constructor.toplevel.class=\
     receiver parameter not applicable for constructor of top-level class
 
-# 0: fragment, 1: symbol, 2: type
+# 0: fragment, 1: symbol, 2: annotated-type
 compiler.err.type.annotation.inadmissible=\
     {0} not expected here\n\
     (to annotate a qualified type, write {1}.{2})

src/jdk.compiler/share/classes/com/sun/tools/javac/util/AbstractDiagnosticFormatter.java

@@ -200,7 +200,10 @@ public abstract class AbstractDiagnosticFormatter implements DiagnosticFormatter
             return formatIterable(d, iterable, l);
         }
         else if (arg instanceof Type type) {
-            return printer.visit(type, l);
+            return printer.visit(type.stripMetadata(), l);
+        }
+        else if (arg instanceof JCDiagnostic.AnnotatedType type) {
+            return printer.visit(type.type(), l);
         }
         else if (arg instanceof Symbol symbol) {
             return printer.visit(symbol, l);

src/jdk.compiler/share/classes/com/sun/tools/javac/util/JCDiagnostic.java

@@ -36,6 +36,7 @@ import javax.tools.JavaFileObject;
 
 import com.sun.tools.javac.api.DiagnosticFormatter;
 import com.sun.tools.javac.code.Lint.LintCategory;
+import com.sun.tools.javac.code.Type;
 import com.sun.tools.javac.tree.EndPosTable;
 import com.sun.tools.javac.tree.JCTree;
 import com.sun.tools.javac.util.DefinedBy.Api;
@@ -606,6 +607,9 @@ public class JCDiagnostic implements Diagnostic<JavaFileObject> {
         }
     }
 
+    /** A diagnostic argument that is a type, which will be printed with type annotations. */
+    public record AnnotatedType(Type type) {}
+
     /**
      * Create a diagnostic object.
      * @param formatter the formatter to use for the diagnostic

test/langtools/tools/javac/annotations/typeAnnotations/failures/IncompatibleTypes.java

@@ -0,0 +1,17 @@
+/*
+ * @test /nodynamiccopyright/
+ * @bug 8291643
+ * @summary Consider omitting type annotations from type error diagnostics
+ * @compile/fail/ref=IncompatibleTypes.out -XDrawDiagnostics IncompatibleTypes.java
+ */
+import java.lang.annotation.*;
+import java.util.List;
+
+class IncompatibleTypes {
+  List<@A Number> f(List<String> xs) {
+    return xs;
+  }
+}
+
+@Target(ElementType.TYPE_USE)
+@interface A { }

test/langtools/tools/javac/annotations/typeAnnotations/failures/IncompatibleTypes.out

@@ -0,0 +1,2 @@
+IncompatibleTypes.java:12:12: compiler.err.prob.found.req: (compiler.misc.inconvertible.types: java.util.List<java.lang.String>, java.util.List<java.lang.Number>)
+1 error

test/langtools/tools/javac/lambda/LambdaConv25.out

@@ -1,2 +1,2 @@
-LambdaConv25.java:19:15: compiler.err.prob.found.req: (compiler.misc.invalid.generic.lambda.target: <X>()void, kindname.interface, LambdaConv25.C)
+LambdaConv25.java:19:15: compiler.err.prob.found.req: (compiler.misc.invalid.generic.lambda.target: ()void, kindname.interface, LambdaConv25.C)
 1 error

test/langtools/tools/javac/warnings/6747671/T6747671.out

@@ -7,6 +7,6 @@ T6747671.java:29:28: compiler.warn.raw.class.use: T6747671.B, T6747671.B<X>
 T6747671.java:32:9: compiler.warn.raw.class.use: T6747671.A, T6747671<E>.A<X>
 T6747671.java:32:20: compiler.warn.raw.class.use: T6747671.A, T6747671<E>.A<X>
 T6747671.java:33:16: compiler.warn.raw.class.use: T6747671.A.Z, T6747671<E>.A<X>.Z<Y>
-T6747671.java:36:9: compiler.warn.raw.class.use: @T6747671.TA T6747671.B, T6747671.B<X>
+T6747671.java:36:9: compiler.warn.raw.class.use: T6747671.B, T6747671.B<X>
 T6747671.java:36:27: compiler.warn.raw.class.use: T6747671.B, T6747671.B<X>
 11 warnings