8265899: Use pattern matching for instanceof at module jdk.compiler(part 1) #3673

lgxbslgx · 2021-04-25T09:20:32Z

Hi all,

This series of patches update the code of the module jdk.compiler by using the pattern matching for instanceof.

This patch would revise the following packages:

com.sun.tools.javac.api
com.sun.tools.javac.file
com.sun.tools.javac.main
com.sun.tools.javac.model
com.sun.tools.javac.platform
com.sun.tools.javac.tree
com.sun.tools.javac.util

Thank you for taking the time to review.

--
Best Regards,
Guoxiong.

Progress

Change must not contain extraneous whitespace
Commit message must refer to an issue
Change must be properly reviewed

Issue

JDK-8265899: Use pattern matching for instanceof at module jdk.compiler(part 1)

Reviewers

Maurizio Cimadamore (@mcimadamore - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/3673/head:pull/3673
$ git checkout pull/3673

Update a local copy of the PR:
$ git checkout pull/3673
$ git pull https://git.openjdk.java.net/jdk pull/3673/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 3673

View PR using the GUI difftool:
$ git pr show -t 3673

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/3673.diff

…art 1)

bridgekeeper · 2021-04-25T09:21:45Z

👋 Welcome back gli! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

openjdk · 2021-04-25T09:24:07Z

@lgxbslgx The following labels will be automatically applied to this pull request:

compiler
javadoc

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing lists. If you would like to change these labels, use the /label pull request command.

lgxbslgx · 2021-04-25T09:28:27Z

/label remove javadoc

openjdk · 2021-04-25T09:28:51Z

@lgxbslgx
The javadoc label was successfully removed.

mlbridge · 2021-04-25T09:37:03Z

Webrevs

01: Full - Incremental (dc6c3dd7)
00: Full (5b298b32)

mcimadamore

Very nice cleanup - left few comments

mcimadamore · 2021-04-26T13:32:43Z

src/jdk.compiler/share/classes/com/sun/tools/javac/api/JavacScope.java

-            JavacScope s = (JavacScope) other;
-            return (env.equals(s.env)
-                && isStarImportScope() == s.isStarImportScope());
+        if (other instanceof JavacScope javacScope) {


Can this be:

return other instanceof JavacScope javacScope && env.equals(javacScope.env) && isStarImportScope() == javacScope.isStarImportScope();

mcimadamore · 2021-04-26T13:37:27Z

src/jdk.compiler/share/classes/com/sun/tools/javac/file/JavacFileManager.java

-            result = new ArrayList<>(((Collection<?>)paths).size());
-        else
+        if (paths != null) {
+            result = new ArrayList<>(paths.size());


This seems odd in the original code - I'd rather have somebody versed in the API double check this - @jonathan-gibbons ? Anyway - this doesn't seem to be related with using pattern matching, so perhaps it's preferrable to just move it out of this PR.

I think that removing the unnecessary instanceof expressions is also the goal of this cleanup. So I want to keep it.

In this case, my logical analysis is shown below.

Please see the code below. The parameter type of the method getJavaFileObjectsFromPaths is Collection<? extends Path>, so we don't need to use paths instanceof Collection<?>. We only need to judge whether paths is null. So I use paths != null instead.

public Iterable<? extends JavaFileObject> getJavaFileObjectsFromPaths( Collection<? extends Path> paths)

Because the paths may be null, I move the following code from top scope to if (paths != null) branch scope to avoid the NPE.

for (Path p: paths) result.add(PathFileObject.forSimplePath(this, fsInfo.getCanonicalFile(p), p));

In my opinion, these two steps are reasonable for removing the instanceof expression.

mcimadamore · 2021-04-26T13:43:14Z

src/jdk.compiler/share/classes/com/sun/tools/javac/model/JavacTypes.java

@@ -329,18 +329,17 @@ private void validateTypeNotIn(TypeMirror t, Set<TypeKind> invalidKinds) {
                || elem.getModifiers().contains(Modifier.PRIVATE))
            return Collections.emptySet();

-        if (!(elem instanceof MethodSymbol))
+        if (!(elem instanceof MethodSymbol methodSymbol))


These two look odd - your cleanup is fine, but it seems in the first cast, we want to wrap with IllegalArgumentException instead of failing with ClassCastException. In the second cast (for class symbol) it seems we're ok with just CCE. I'm fine with leaving this as per your cleanup - just noting the inconsistency.

mcimadamore · 2021-04-26T13:44:28Z

src/jdk.compiler/share/classes/com/sun/tools/javac/tree/JCTree.java

@@ -2178,7 +2178,7 @@ protected JCInstanceOf(JCExpression expr, JCTree pattern) {

        @Override @DefinedBy(Api.COMPILER_TREE)
        public JCPattern getPattern() {
-            return pattern instanceof JCPattern ? (JCPattern) pattern : null;
+            return pattern instanceof JCPattern jcPattern ? jcPattern : null;


Using patterns to implement patterns support :-)

mcimadamore

Looks good

mcimadamore · 2021-04-26T16:38:34Z

src/jdk.compiler/share/classes/com/sun/tools/javac/file/JavacFileManager.java

-            result = new ArrayList<>(((Collection<?>)paths).size());
-        else
+        if (paths != null) {
+            result = new ArrayList<>(paths.size());


openjdk · 2021-04-26T17:31:38Z

@lgxbslgx This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8265899: Use pattern matching for instanceof at module jdk.compiler(part 1)

Reviewed-by: mcimadamore

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 25 new commits pushed to the master branch:

efe6b93: 8265961: Fix comments in logging.properties
65c19c4: 4926314: Optimize Reader.read(CharBuffer)
082abbd: 8265900: Use pattern matching for instanceof at module jdk.compiler(part 2)
851b219: 8265901: Use pattern matching for instanceof at module jdk.compiler(part 3)
fb8f0c5: 8261168: Convert javadoc tool to use Stream.toList()
8559a53: 8265394: G1: Improve assert in HeapRegion::reset_not_compacted_after_full_gc
68011c6: 8265928: G1: Update copyright in several files
222f9f0: 8265682: G1: Mutex::_name dangling in HeapRegionRemSet references after JDK-8264146
2b09ff2: 8232765: NullPointerException at Types.eraseNotNeeded() when compiling a class
b9f66d9: 8264188: Improve handling of assembly files in the JDK
... and 15 more: https://git.openjdk.java.net/jdk/compare/f6e22d14e3ee529f21ab8747cfbafe72b906ec68...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change. Possible candidates are the reviewers of this PR (@mcimadamore) but any other Committer may sponsor as well.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

lgxbslgx · 2021-04-26T17:32:10Z

/integrate

openjdk · 2021-04-26T17:36:19Z

@lgxbslgx
Your change (at version dc6c3dd) is now ready to be sponsored by a Committer.

lgxbslgx · 2021-04-26T18:25:42Z

@mcimadamore Thank you for your review. May I ask your help to sponsor this patch?

mcimadamore · 2021-04-26T20:15:11Z

/sponsor

openjdk · 2021-04-26T20:16:18Z

@mcimadamore @lgxbslgx Since your change was applied there have been 29 commits pushed to the master branch:

a6f2863: 8266003: ProblemList sanity/client/SwingSet/src/ButtonDemoScreenshotTest.java on macosx-all
852a41d: 8258625: [JVMCI] refactor and unify JVMCI readFieldValue path
b5c6351: 8264663: Update test SuspendWithCurrentThread.java to verify that suspend doesn't exit until resumed
b524a81: 8265982: JDK-8264188 breaks build on macOS-aarch64
efe6b93: 8265961: Fix comments in logging.properties
65c19c4: 4926314: Optimize Reader.read(CharBuffer)
082abbd: 8265900: Use pattern matching for instanceof at module jdk.compiler(part 2)
851b219: 8265901: Use pattern matching for instanceof at module jdk.compiler(part 3)
fb8f0c5: 8261168: Convert javadoc tool to use Stream.toList()
8559a53: 8265394: G1: Improve assert in HeapRegion::reset_not_compacted_after_full_gc
... and 19 more: https://git.openjdk.java.net/jdk/compare/f6e22d14e3ee529f21ab8747cfbafe72b906ec68...master

Your commit was automatically rebased without conflicts.

Pushed as commit 41daa88.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

8265899: Use pattern matching for instanceof at module jdk.compiler(p…

5b298b3

…art 1)

openjdk bot added javadoc javadoc-dev@openjdk.org compiler compiler-dev@openjdk.org labels Apr 25, 2021

openjdk bot removed the javadoc javadoc-dev@openjdk.org label Apr 25, 2021

lgxbslgx marked this pull request as ready for review April 25, 2021 09:30

openjdk bot added the rfr Pull request is ready for review label Apr 25, 2021

mcimadamore reviewed Apr 26, 2021

View reviewed changes

Cleanup method JavacScope.equals

dc6c3dd

mcimadamore approved these changes Apr 26, 2021

View reviewed changes

openjdk bot added ready Pull request is ready to be integrated sponsor Pull request is ready to be sponsored labels Apr 26, 2021

openjdk bot closed this Apr 26, 2021

openjdk bot added integrated Pull request has been integrated and removed sponsor Pull request is ready to be sponsored ready Pull request is ready to be integrated rfr Pull request is ready for review labels Apr 26, 2021

lgxbslgx deleted the JDK-8265899 branch April 26, 2021 23:26

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

8265899: Use pattern matching for instanceof at module jdk.compiler(part 1) #3673

8265899: Use pattern matching for instanceof at module jdk.compiler(part 1) #3673

lgxbslgx commented Apr 25, 2021 •

edited by openjdk bot

Loading

bridgekeeper bot commented Apr 25, 2021

openjdk bot commented Apr 25, 2021

lgxbslgx commented Apr 25, 2021

openjdk bot commented Apr 25, 2021

mlbridge bot commented Apr 25, 2021 •

edited

Loading

mcimadamore left a comment

mcimadamore Apr 26, 2021

lgxbslgx Apr 26, 2021

mcimadamore Apr 26, 2021

lgxbslgx Apr 26, 2021

mcimadamore Apr 26, 2021

mcimadamore Apr 26, 2021

mcimadamore Apr 26, 2021

mcimadamore left a comment

mcimadamore Apr 26, 2021

openjdk bot commented Apr 26, 2021 •

edited

Loading

lgxbslgx commented Apr 26, 2021

openjdk bot commented Apr 26, 2021

lgxbslgx commented Apr 26, 2021

mcimadamore commented Apr 26, 2021

openjdk bot commented Apr 26, 2021

8265899: Use pattern matching for instanceof at module jdk.compiler(part 1) #3673

8265899: Use pattern matching for instanceof at module jdk.compiler(part 1) #3673

Conversation

lgxbslgx commented Apr 25, 2021 • edited by openjdk bot Loading

Progress

Issue

Reviewers

Reviewing

bridgekeeper bot commented Apr 25, 2021

openjdk bot commented Apr 25, 2021

lgxbslgx commented Apr 25, 2021

openjdk bot commented Apr 25, 2021

mlbridge bot commented Apr 25, 2021 • edited Loading

Webrevs

mcimadamore left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

mcimadamore left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

openjdk bot commented Apr 26, 2021 • edited Loading

lgxbslgx commented Apr 26, 2021

openjdk bot commented Apr 26, 2021

lgxbslgx commented Apr 26, 2021

mcimadamore commented Apr 26, 2021

openjdk bot commented Apr 26, 2021

lgxbslgx commented Apr 25, 2021 •

edited by openjdk bot

Loading

mlbridge bot commented Apr 25, 2021 •

edited

Loading

openjdk bot commented Apr 26, 2021 •

edited

Loading