Don't erase the type argument of receiver

checker/jtreg/nullness/MethodReceiverTypeErrorMessageTest.java

@@ -0,0 +1,20 @@
+/*
+ * @test
+ * @summary Test case for method receiver type in error message. If it is a non-raw type, it should be printed as such.
+ *
+ * @compile/fail/ref=MethodReceiverTypeErrorMessageTest.out -XDrawDiagnostics -processor org.checkerframework.checker.nullness.NullnessChecker MethodReceiverTypeErrorMessageTest.java
+ */
+public class MethodReceiverTypeErrorMessageTest<T> {
+
+    MethodReceiverTypeErrorMessageTest() {
+        foo();
+    }
+
+    void foo() {}
+}
+
+class sub extends MethodReceiverTypeErrorMessageTest<String> {
+    sub() {
+        foo();
+    }
+}

checker/jtreg/nullness/MethodReceiverTypeErrorMessageTest.out

@@ -0,0 +1,7 @@
+MethodReceiverTypeErrorMessageTest.java:10:12: compiler.err.proc.messager: [method.invocation.invalid] call to foo() not allowed on the given receiver.
+found   : @UnderInitialization(MethodReceiverTypeErrorMessageTest.class) MethodReceiverTypeErrorMessageTest<T extends @Initialized Object>
+required: @Initialized MethodReceiverTypeErrorMessageTest<T extends @Initialized Object>
+MethodReceiverTypeErrorMessageTest.java:18:12: compiler.err.proc.messager: [method.invocation.invalid] call to foo() not allowed on the given receiver.
+found   : @UnderInitialization(sub.class) sub
+required: @Initialized MethodReceiverTypeErrorMessageTest<@Initialized String>
+2 errors

checker/tests/nullness/ReceiverTypeArgs.java

@@ -0,0 +1,19 @@
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+public class ReceiverTypeArgs {
+    static class Box<T> {
+        T item;
+
+        public Box(T item) {
+            this.item = item;
+        }
+
+        void test(Box<@NonNull T> this) {}
+    }
+
+    private static void foo(Box<@Nullable String> box) {
+        // :: error: (method.invocation.invalid)
+        box.test();
+    }
+}

framework/src/main/java/org/checkerframework/common/basetype/BaseTypeVisitor.java

@@ -3772,8 +3772,8 @@ protected void checkMethodInvocability(
             return;
         }
 
-        AnnotatedTypeMirror methodReceiver = method.getReceiverType().getErased();
-        AnnotatedTypeMirror treeReceiver = methodReceiver.shallowCopy(false);
+        AnnotatedDeclaredType methodReceiver = method.getReceiverType();
+        AnnotatedDeclaredType treeReceiver = methodReceiver.shallowCopy(false);
         AnnotatedTypeMirror rcv = atypeFactory.getReceiverType(tree);
 
         treeReceiver.addAnnotations(rcv.getEffectiveAnnotations());
@@ -3782,10 +3782,10 @@ protected void checkMethodInvocability(
             // The diagnostic can be a bit misleading because the check is of the receiver but
             // `tree` is the entire method invocation (where the receiver might be implicit).
             commonAssignmentCheckStartDiagnostic(methodReceiver, treeReceiver, tree);
-            boolean success = typeHierarchy.isSubtype(treeReceiver, methodReceiver);
-            commonAssignmentCheckEndDiagnostic(success, null, methodReceiver, treeReceiver, tree);
+            boolean success = typeHierarchy.isSubtype(rcv, methodReceiver);
+            commonAssignmentCheckEndDiagnostic(success, null, methodReceiver, rcv, tree);
             if (!success) {
-                reportMethodInvocabilityError(tree, treeReceiver, methodReceiver);
+                reportMethodInvocabilityError(tree, rcv, methodReceiver);
             }
         }
     }

javacutil/src/main/java/org/checkerframework/javacutil/TreeUtils.java

@@ -251,7 +251,7 @@ public static boolean isSelfAccess(ExpressionTree tree) {
      * @param tree an expression tree
      * @return the outermost non-parenthesized tree enclosed by the given tree
      */
-    @SuppressWarnings("interning:return.type.incompatible") // pol ymorphism implementation
+    @SuppressWarnings("interning:return.type.incompatible") // polymorphism implementation
     public static @PolyInterned ExpressionTree withoutParens(@PolyInterned ExpressionTree tree) {
         ExpressionTree t = tree;
         while (t.getKind() == Tree.Kind.PARENTHESIZED) {