JDK 16 RFR of JDK-8250213: Address use of default constructors in com.sun.source.util

[Jonathan Gibbons]

+1

On 7/27/20 9:25 AM, Joe Darcy wrote:
> Hi Jon,
>
> Updated webrev to improve the docs for non-abstract classes:
>
>     http://cr.openjdk.java.net/~darcy/8250213.1/
>
> Patch below. For the network version of these changes, as follow-up 
> work  Alan may change the public constructor of abstract classes to 
> protected.
>
> Thanks,
>
> -Joe
>
> --- 
> old/src/jdk.compiler/share/classes/com/sun/source/util/DocTreePathScanner.java 
> 2020-07-27 09:20:26.556000000 -0700
> +++ 
> new/src/jdk.compiler/share/classes/com/sun/source/util/DocTreePathScanner.java 
> 2020-07-27 09:20:25.476000000 -0700
> @@ -39,6 +39,11 @@
>   */
>  public class DocTreePathScanner<R, P> extends DocTreeScanner<R, P> {
>      /**
> +     * Constructs a {@code DocTreePathScanner}.
> +     */
> +    public DocTreePathScanner() {}
> +
> +    /**
>       * Scans a tree from a position identified by a tree path.
>       * @param path the path
>       * @param p a value to be passed to visitor methods
> --- 
> old/src/jdk.compiler/share/classes/com/sun/source/util/DocTreeScanner.java 
> 2020-07-27 09:20:28.600000000 -0700
> +++ 
> new/src/jdk.compiler/share/classes/com/sun/source/util/DocTreeScanner.java 
> 2020-07-27 09:20:27.504000000 -0700
> @@ -68,6 +68,10 @@
>   * @since 1.8
>   */
>  public class DocTreeScanner<R,P> implements DocTreeVisitor<R,P> {
> +    /**
> +     * Constructs a {@code DocTreeScanner}.
> +     */
> +    public DocTreeScanner() {}
>
>      /**
>       * Scans a single node.
> --- 
> old/src/jdk.compiler/share/classes/com/sun/source/util/DocTrees.java 
> 2020-07-27 09:20:30.312000000 -0700
> +++ 
> new/src/jdk.compiler/share/classes/com/sun/source/util/DocTrees.java 
> 2020-07-27 09:20:29.492000000 -0700
> @@ -47,6 +47,11 @@
>   */
>  public abstract class DocTrees extends Trees {
>      /**
> +     * Constructor for subclasses to call.
> +     */
> +    public DocTrees() {}
> +
> +    /**
>       * Returns a DocTrees object for a given CompilationTask.
>       * @param task the compilation task for which to get the Trees 
> object
>       * @return the DocTrees object
> --- 
> old/src/jdk.compiler/share/classes/com/sun/source/util/JavacTask.java 
> 2020-07-27 09:20:32.088000000 -0700
> +++ 
> new/src/jdk.compiler/share/classes/com/sun/source/util/JavacTask.java 
> 2020-07-27 09:20:31.224000000 -0700
> @@ -50,6 +50,10 @@
>   * @since 1.6
>   */
>  public abstract class JavacTask implements CompilationTask {
> +    /**
> +     * Constructor for subclasses to call.
> +     */
> +    public JavacTask() {}
>
>      /**
>       * Returns the {@code JavacTask} for a {@code 
> ProcessingEnvironment}.
> --- 
> old/src/jdk.compiler/share/classes/com/sun/source/util/TreePathScanner.java 
> 2020-07-27 09:20:33.688000000 -0700
> +++ 
> new/src/jdk.compiler/share/classes/com/sun/source/util/TreePathScanner.java 
> 2020-07-27 09:20:32.804000000 -0700
> @@ -43,6 +43,10 @@
>   * @since 1.6
>   */
>  public class TreePathScanner<R, P> extends TreeScanner<R, P> {
> +    /**
> +     * Constructs a {@code TreePathScanner}.
> +     */
> +    public TreePathScanner() {}
>
>      /**
>       * Scans a tree from a position identified by a TreePath.
> --- 
> old/src/jdk.compiler/share/classes/com/sun/source/util/TreeScanner.java 
> 2020-07-27 09:20:35.172000000 -0700
> +++ 
> new/src/jdk.compiler/share/classes/com/sun/source/util/TreeScanner.java 
> 2020-07-27 09:20:34.448000000 -0700
> @@ -75,6 +75,10 @@
>   * @since 1.6
>   */
>  public class TreeScanner<R,P> implements TreeVisitor<R,P> {
> +    /**
> +     * Constructs a {@code TreeScanner}.
> +     */
> +    public TreeScanner() {}
>
>      /**
>       * Scans a single node.
> --- old/src/jdk.compiler/share/classes/com/sun/source/util/Trees.java 
> 2020-07-27 09:20:36.912000000 -0700
> +++ new/src/jdk.compiler/share/classes/com/sun/source/util/Trees.java 
> 2020-07-27 09:20:36.004000000 -0700
> @@ -53,6 +53,11 @@
>   */
>  public abstract class Trees {
>      /**
> +     * Constructor for subclasses to call.
> +     */
> +    public Trees() {}
> +
> +    /**
>       * Returns a Trees object for a given CompilationTask.
>       * @param task the compilation task for which to get the Trees 
> object
>       * @throws IllegalArgumentException if the task does not support 
> the Trees API.
> --- old/src/jdk.compiler/share/classes/com/sun/tools/javac/Main.java 
> 2020-07-27 09:20:38.680000000 -0700
> +++ new/src/jdk.compiler/share/classes/com/sun/tools/javac/Main.java 
> 2020-07-27 09:20:37.764000000 -0700
> @@ -34,6 +34,11 @@
>   * module for details on replacement APIs.
>   */
>  public class Main {
> +    /**
> +     * Do not call.
> +     */
> +    @Deprecated(since="16", forRemoval=true)
> +    public Main(){}
>
>      /** Main entry point for the launcher.
>       *  Note: This method calls System.exit.
>
> On 7/23/2020 10:17 AM, Joe Darcy wrote:
>> Hi Jon,
>>
>> For the non-abstract classes, I'm happy to change the verbiage to the 
>> true (if not very informative) "Creates a $FOO."
>>
>> Longer term, deprecating the unintended constructors for removal 
>> would be fine too. (This patch is the first in a series to clean-up 
>> the JDK with the intention of introducing a new lint warning for 
>> using default constructors.)
>>
>> Thanks,
>>
>> -Joe
>>
>>