[records] [@NonNull] slight refactor to ensure any generated canonical constructor is visible to downstream APs

We used to remove the canonical constructor on a record that javac generates, and replace it with our own, as we put null checks in it.
However, the type mirrors and such Annotation Processors use already have the implicit canonical constructor available. Instead of
trying to remove those, let's just take the existing implicit constructor and add to that (and mark it explicit, of course).

src/core/lombok/javac/handlers/HandleNonNull.java

@@ -71,7 +71,7 @@ import lombok.spi.Provides;
 @Provides
 @HandlerPriority(value = 512) // 2^9; onParameter=@__(@NonNull) has to run first.
 public class HandleNonNull extends JavacAnnotationHandler<NonNull> {
-	private JCMethodDecl createRecordArgslessConstructor(JavacNode typeNode, JavacNode source) {
+	private JCMethodDecl createRecordArgslessConstructor(JavacNode typeNode, JavacNode source, JCMethodDecl existingCtr) {
 		JavacTreeMaker maker = typeNode.getTreeMaker();
 		
 		java.util.List<JCVariableDecl> fields = new ArrayList<JCVariableDecl>();
@@ -94,8 +94,18 @@ public class HandleNonNull extends JavacAnnotationHandler<NonNull> {
 		
 		JCModifiers mods = maker.Modifiers(toJavacModifier(AccessLevel.PUBLIC) | COMPACT_RECORD_CONSTRUCTOR, List.<JCAnnotation>nil());
 		JCBlock body = maker.Block(0L, List.<JCStatement>nil());
-		JCMethodDecl constr = maker.MethodDef(mods, typeNode.toName("<init>"), null, List.<JCTypeParameter>nil(), params.toList(), List.<JCExpression>nil(), body, null);
-		return recursiveSetGeneratedBy(constr, source);
+		if (existingCtr == null) {
+			JCMethodDecl constr = maker.MethodDef(mods, typeNode.toName("<init>"), null, List.<JCTypeParameter>nil(), params.toList(), List.<JCExpression>nil(), body, null);
+			return recursiveSetGeneratedBy(constr, source);
+		} else {
+			existingCtr.mods = mods;
+			existingCtr.params = params.toList();
+			existingCtr.body = body;
+			existingCtr = recursiveSetGeneratedBy(existingCtr, source);
+			addSuppressWarningsAll(existingCtr.mods, typeNode, typeNode.getNodeFor(getGeneratedBy(existingCtr)), typeNode.getContext());
+			addGenerated(existingCtr.mods, typeNode, typeNode.getNodeFor(getGeneratedBy(existingCtr)), typeNode.getContext());
+			return existingCtr;
+		}
 	}
 	
 	/**
@@ -113,16 +123,17 @@ public class HandleNonNull extends JavacAnnotationHandler<NonNull> {
 		JCClassDecl cDecl = (JCClassDecl) typeNode.get();
 		if ((cDecl.mods.flags & RECORD) == 0) return answer;
 		
-		ListBuffer<JCTree> newDefs = new ListBuffer<JCTree>();
 		boolean generateConstructor = false;
 		
+		JCMethodDecl existingCtr = null;
+		
 		for (JCTree def : cDecl.defs) {
-			boolean remove = false;
 			if (def instanceof JCMethodDecl) {
 				JCMethodDecl md = (JCMethodDecl) def;
 				if (md.name.contentEquals("<init>")) {
 					if ((md.mods.flags & Flags.GENERATEDCONSTR) != 0) {
-						remove = true;
+						existingCtr = md;
+						existingCtr.mods.flags = existingCtr.mods.flags & ~Flags.GENERATEDCONSTR;
 						generateConstructor = true;
 					} else {
 						if (!isTolerate(typeNode, md)) {
@@ -134,13 +145,16 @@ public class HandleNonNull extends JavacAnnotationHandler<NonNull> {
 					}
 				}
 			}
-			if (!remove) newDefs.append(def);
 		}
 		
 		if (generateConstructor) {
-			cDecl.defs = newDefs.toList();
-			JCMethodDecl ctr = createRecordArgslessConstructor(typeNode, source);
-			injectMethod(typeNode, ctr);
+			JCMethodDecl ctr;
+			if (existingCtr != null) {
+				ctr = createRecordArgslessConstructor(typeNode, source, existingCtr);
+			} else {
+				ctr = createRecordArgslessConstructor(typeNode, source, null);
+				injectMethod(typeNode, ctr);
+			}
 			answer = answer.prepend(ctr);
 		}
 		

test/transform/resource/after-delombok/NonNullExistingConstructorOnRecord.java

@@ -1,12 +1,6 @@
 // version 16:
 import lombok.NonNull;
 public record NonNullExistingConstructorOnRecord(@NonNull String a, @NonNull String b) {
-	public NonNullExistingConstructorOnRecord(@NonNull String b) {
-		this("default", b);
-		if (b == null) {
-			throw new java.lang.NullPointerException("b is marked non-null but is null");
-		}
-	}
 	@java.lang.SuppressWarnings("all")
 	public NonNullExistingConstructorOnRecord {
 		if (a == null) {
@@ -16,4 +10,10 @@ public record NonNullExistingConstructorOnRecord(@NonNull String a, @NonNull Str
 			throw new java.lang.NullPointerException("b is marked non-null but is null");
 		}
 	}
+	public NonNullExistingConstructorOnRecord(@NonNull String b) {
+		this("default", b);
+		if (b == null) {
+			throw new java.lang.NullPointerException("b is marked non-null but is null");
+		}
+	}
 }