Cherry-pick upstream changes.

changelog/@unreleased/pr-615.v2.yml

@@ -0,0 +1,5 @@
+type: improvement
+improvement:
+  description: Cherry-pick upstream changes.
+  links:
+  - https://github.com/palantir/palantir-java-format/pull/615

palantir-java-format/src/main/java/com/palantir/javaformat/java/JavaInputAstVisitor.java

@@ -1981,8 +1981,10 @@ public void visitClassDeclaration(ClassTree node) {
         sync(node);
         List<Op> breaks = visitModifiers(
                 node.getModifiers(), Direction.VERTICAL, /* declarationAnnotationBreak= */ Optional.empty());
+        List<? extends Tree> permitsTypes = getPermitsClause(node);
         boolean hasSuperclassType = node.getExtendsClause() != null;
         boolean hasSuperInterfaceTypes = !node.getImplementsClause().isEmpty();
+        boolean hasPermitsTypes = !permitsTypes.isEmpty();
         builder.addAll(breaks);
         token(node.getKind() == Tree.Kind.INTERFACE ? "interface" : "class");
         builder.space();
@@ -1994,30 +1996,18 @@ public void visitClassDeclaration(ClassTree node) {
         {
             if (!node.getTypeParameters().isEmpty()) {
                 typeParametersRest(
-                        node.getTypeParameters(), hasSuperclassType || hasSuperInterfaceTypes ? plusFour : ZERO);
+                        node.getTypeParameters(),
+                        hasSuperclassType || hasSuperInterfaceTypes || hasPermitsTypes ? plusFour : ZERO);
             }
             if (hasSuperclassType) {
                 builder.breakToFill(" ");
                 token("extends");
                 builder.space();
                 scan(node.getExtendsClause(), null);
             }
-            if (hasSuperInterfaceTypes) {
-                builder.breakToFill(" ");
-                builder.open(node.getImplementsClause().size() > 1 ? plusFour : ZERO);
-                token(node.getKind() == Tree.Kind.INTERFACE ? "extends" : "implements");
-                builder.space();
-                boolean first = true;
-                for (Tree superInterfaceType : node.getImplementsClause()) {
-                    if (!first) {
-                        token(",");
-                        builder.breakOp(" ");
-                    }
-                    scan(superInterfaceType, null);
-                    first = false;
-                }
-                builder.close();
-            }
+            classDeclarationTypeList(
+                    node.getKind() == Tree.Kind.INTERFACE ? "extends" : "implements", node.getImplementsClause());
+            classDeclarationTypeList("permits", permitsTypes);
         }
         builder.close();
         if (node.getMembers() == null) {
@@ -2290,6 +2280,8 @@ boolean nextIsModifier() {
             case "native":
             case "strictfp":
             case "default":
+            case "sealed":
+            case "non-sealed":
                 return true;
             default:
                 return false;
@@ -3673,6 +3665,30 @@ protected void addBodyDeclarations(
             }
         }
     }
+    /** Gets the permits clause for the given node. This is only available in Java 15 and later. */
+    protected List<? extends Tree> getPermitsClause(ClassTree node) {
+        return ImmutableList.of();
+    }
+
+    private void classDeclarationTypeList(String token, List<? extends Tree> types) {
+        if (types.isEmpty()) {
+            return;
+        }
+        builder.breakToFill(" ");
+        builder.open(types.size() > 1 ? plusFour : ZERO);
+        token(token);
+        builder.space();
+        boolean first = true;
+        for (Tree type : types) {
+            if (!first) {
+                token(",");
+                builder.breakOp(" ");
+            }
+            scan(type, null);
+            first = false;
+        }
+        builder.close();
+    }
 
     /**
      * The parser expands multi-variable declarations into separate single-variable declarations. All of the fragments

palantir-java-format/src/main/java/com/palantir/javaformat/java/ModifierOrderer.java

@@ -35,41 +35,6 @@
 /** Fixes sequences of modifiers to be in JLS order. */
 final class ModifierOrderer {
 
-    /** Returns the {@link javax.lang.model.element.Modifier} for the given token kind, or {@code null}. */
-    private static Modifier getModifier(TokenKind kind) {
-        if (kind == null) {
-            return null;
-        }
-        switch (kind) {
-            case PUBLIC:
-                return Modifier.PUBLIC;
-            case PROTECTED:
-                return Modifier.PROTECTED;
-            case PRIVATE:
-                return Modifier.PRIVATE;
-            case ABSTRACT:
-                return Modifier.ABSTRACT;
-            case STATIC:
-                return Modifier.STATIC;
-            case DEFAULT:
-                return Modifier.DEFAULT;
-            case FINAL:
-                return Modifier.FINAL;
-            case TRANSIENT:
-                return Modifier.TRANSIENT;
-            case VOLATILE:
-                return Modifier.VOLATILE;
-            case SYNCHRONIZED:
-                return Modifier.SYNCHRONIZED;
-            case NATIVE:
-                return Modifier.NATIVE;
-            case STRICTFP:
-                return Modifier.STRICTFP;
-            default:
-                return null;
-        }
-    }
-
     /** Reorders all modifiers in the given text to be in JLS order. */
     static JavaInput reorderModifiers(String text) throws FormatterException {
         return reorderModifiers(new JavaInput(text), ImmutableList.of(Range.closedOpen(0, text.length())));
@@ -143,7 +108,44 @@ private static void addTrivia(StringBuilder replacement, ImmutableList<? extends
      * Returns the given token as a {@link javax.lang.model.element.Modifier}, or {@code null} if it is not a modifier.
      */
     private static Modifier asModifier(Token token) {
-        return getModifier(((JavaInput.Tok) token.getTok()).kind());
+        TokenKind kind = ((JavaInput.Tok) token.getTok()).kind();
+        if (kind != null) {
+            switch (kind) {
+                case PUBLIC:
+                    return Modifier.PUBLIC;
+                case PROTECTED:
+                    return Modifier.PROTECTED;
+                case PRIVATE:
+                    return Modifier.PRIVATE;
+                case ABSTRACT:
+                    return Modifier.ABSTRACT;
+                case STATIC:
+                    return Modifier.STATIC;
+                case DEFAULT:
+                    return Modifier.DEFAULT;
+                case FINAL:
+                    return Modifier.FINAL;
+                case TRANSIENT:
+                    return Modifier.TRANSIENT;
+                case VOLATILE:
+                    return Modifier.VOLATILE;
+                case SYNCHRONIZED:
+                    return Modifier.SYNCHRONIZED;
+                case NATIVE:
+                    return Modifier.NATIVE;
+                case STRICTFP:
+                    return Modifier.STRICTFP;
+                default: // fall out
+            }
+        }
+        switch (token.getTok().getText()) {
+            case "non-sealed":
+                return Modifier.valueOf("NON_SEALED");
+            case "sealed":
+                return Modifier.valueOf("SEALED");
+            default:
+                return null;
+        }
     }
 
     /** Applies replacements to the given string. */

palantir-java-format/src/main/java/com/palantir/javaformat/java/RemoveUnusedImports.java

@@ -27,6 +27,7 @@
 import com.palantir.javaformat.Newlines;
 import com.sun.source.doctree.DocCommentTree;
 import com.sun.source.doctree.ReferenceTree;
+import com.sun.source.tree.CaseTree;
 import com.sun.source.tree.IdentifierTree;
 import com.sun.source.tree.ImportTree;
 import com.sun.source.tree.Tree;
@@ -44,7 +45,9 @@
 import com.sun.tools.javac.tree.JCTree.JCImport;
 import com.sun.tools.javac.util.Context;
 import com.sun.tools.javac.util.Options;
+import java.lang.reflect.Method;
 import java.util.LinkedHashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
@@ -97,6 +100,31 @@ public Void visitIdentifier(IdentifierTree tree, Void unused) {
             return null;
         }
 
+        // TODO(fwindheuser): remove this override when pattern matching in switch is no longer a preview
+        // feature, and TreePathScanner visits CaseTree#getLabels instead of CaseTree#getExpressions
+        @SuppressWarnings("unchecked") // reflection
+        @Override
+        public Void visitCase(CaseTree tree, Void unused) {
+            if (CASE_TREE_GET_LABELS != null) {
+                try {
+                    scan((List<? extends Tree>) CASE_TREE_GET_LABELS.invoke(tree), null);
+                } catch (ReflectiveOperationException e) {
+                    throw new LinkageError(e.getMessage(), e);
+                }
+            }
+            return super.visitCase(tree, null);
+        }
+
+        private static final Method CASE_TREE_GET_LABELS = caseTreeGetLabels();
+
+        private static Method caseTreeGetLabels() {
+            try {
+                return CaseTree.class.getMethod("getLabels");
+            } catch (NoSuchMethodException e) {
+                return null;
+            }
+        }
+
         @Override
         public Void scan(Tree tree, Void unused) {
             if (tree == null) {
@@ -127,8 +155,9 @@ public Void visitIdentifier(com.sun.source.doctree.IdentifierTree node, Void aVo
             @Override
             public Void visitReference(ReferenceTree referenceTree, Void unused) {
                 DCReference reference = (DCReference) referenceTree;
-                long basePos = reference.getSourcePosition(
-                        (DCTree.DCDocComment) getCurrentPath().getDocComment());
+                long basePos = reference
+                        .pos((DCTree.DCDocComment) getCurrentPath().getDocComment())
+                        .getStartPosition();
                 // the position of trees inside the reference node aren't stored, but the qualifier's
                 // start position is the beginning of the reference node
                 if (reference.qualifierExpression != null) {