Restore Eclipse 2019-6 compatibility

See gh-143

Author: philwebb

spring-javaformat/spring-javaformat-formatter-eclipse-rewriter/src/main/java/io/spring/javaformat/formatter/eclipse/rewrite/EclipseRewriter.java

@@ -27,10 +27,13 @@
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
 import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.Set;
 
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.FieldVisitor;
 import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Opcodes;
 
@@ -41,6 +44,22 @@
  */
 public final class EclipseRewriter {
 
+	private static final Set<String> UPDATED_METHODS;
+	static {
+		Set<String> updatedMethods = new LinkedHashSet<String>();
+		updatedMethods.add("prepareWraps");
+		updatedMethods.add("tokenizeSource");
+		UPDATED_METHODS = Collections.unmodifiableSet(updatedMethods);
+	}
+
+	private static final Set<String> UPDATED_FIELDS;
+	static {
+		Set<String> updatedFields = new LinkedHashSet<String>();
+		updatedFields.add("sourceLevel");
+		updatedFields.add("tokens");
+		UPDATED_FIELDS = Collections.unmodifiableSet(updatedFields);
+	}
+
 	private EclipseRewriter() {
 	}
 
@@ -73,10 +92,18 @@ private static class DefaultCodeFormatterManipulator extends ClassVisitor {
 			super(Opcodes.ASM5, visitor);
 		}
 
+		@Override
+		public FieldVisitor visitField(int access, String name, String desc, String signature, Object value) {
+			if (access == Opcodes.ACC_PRIVATE && UPDATED_FIELDS.contains(name)) {
+				access = Opcodes.ACC_PROTECTED;
+			}
+			return super.visitField(access, name, desc, signature, value);
+		}
+
 		@Override
 		public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
-			if ("prepareWraps".equals(name) && Opcodes.ACC_PRIVATE == access) {
-				return super.visitMethod(Opcodes.ACC_PROTECTED, name, desc, signature, exceptions);
+			if (access == Opcodes.ACC_PRIVATE && UPDATED_METHODS.contains(name)) {
+				access = Opcodes.ACC_PROTECTED;
 			}
 			return new DefaultCodeFormatterMethodManipulator(
 					super.visitMethod(access, name, desc, signature, exceptions));
@@ -92,9 +119,8 @@ private static class DefaultCodeFormatterMethodManipulator extends MethodVisitor
 
 		@Override
 		public void visitMethodInsn(int opcode, String owner, String name, String desc, boolean itf) {
-			if ("prepareWraps".equals(name) && opcode == Opcodes.INVOKESPECIAL) {
-				super.visitMethodInsn(Opcodes.INVOKEVIRTUAL, owner, name, desc, itf);
-				return;
+			if (opcode == Opcodes.INVOKESPECIAL && UPDATED_METHODS.contains(name)) {
+				opcode = Opcodes.INVOKEVIRTUAL;
 			}
 			super.visitMethodInsn(opcode, owner, name, desc, itf);
 		}

spring-javaformat/spring-javaformat-formatter-eclipse/src/main/java/org/eclipse/jdt/internal/formatter/ExtendedCodeFormatter.java

@@ -21,7 +21,11 @@
 import java.util.List;
 import java.util.Map;
 
+import org.eclipse.jdt.core.compiler.InvalidInputException;
 import org.eclipse.jdt.core.dom.ASTNode;
+import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
+import org.eclipse.jdt.internal.compiler.parser.Scanner;
+import org.eclipse.jdt.internal.compiler.parser.TerminalTokens;
 import org.eclipse.jdt.internal.formatter.Preparator.Phase;
 
 /**
@@ -32,6 +36,8 @@
  */
 public class ExtendedCodeFormatter extends DefaultCodeFormatter {
 
+	private static boolean useLegacyTokenize = false;
+
 	private final List<Preparator> preparators = new ArrayList<>();
 
 	public ExtendedCodeFormatter() {
@@ -54,6 +60,43 @@ protected void addPreparator(Preparator preparator) {
 		this.preparators.add(preparator);
 	}
 
+	@Override
+	protected void tokenizeSource(int kind) {
+		if (useLegacyTokenize) {
+			legacyTokenizeSource(kind);
+			return;
+		}
+		try {
+			super.tokenizeSource(kind);
+		}
+		catch (NoSuchMethodError ex) {
+			useLegacyTokenize = true;
+			legacyTokenizeSource(kind);
+		}
+	}
+
+	private void legacyTokenizeSource(int kind) {
+		this.tokens.clear();
+		long sourceLevel = CompilerOptions.versionToJdkLevel(this.sourceLevel);
+		Scanner scanner = new Scanner(true, false, false, sourceLevel, null, null, false);
+		scanner.setSource(this.sourceArray);
+		scanner.fakeInModule = (kind & K_MODULE_INFO) != 0;
+		while (true) {
+			try {
+				int tokenType = scanner.getNextToken();
+				if (tokenType == TerminalTokens.TokenNameEOF) {
+					break;
+				}
+				Token token = Token.fromCurrent(scanner, tokenType);
+				this.tokens.add(token);
+			}
+			catch (InvalidInputException ex) {
+				Token token = Token.fromCurrent(scanner, TerminalTokens.TokenNameNotAToken);
+				this.tokens.add(token);
+			}
+		}
+	}
+
 	@Override
 	protected void prepareWraps(int kind) {
 		ASTNode astRoot = getField("astRoot", ASTNode.class);