8374953: Add note on about implicit state when comparing TypeMirrors

[jddarcy]

The API note about comparing Element's:

The identity of an element involves implicit state not directly accessible from the element's methods, including state about the presence of unrelated types. Element objects created by different implementations of these interfaces should not be expected to be equal even if "the same" element is being modeled; this is analogous to the inequality of Class objects for the same class file loaded through different class loaders.

is equally applicable to comparing TypeMirror and an analagous note should be present on the methods used to compare TypeMirror's.

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8374953: Add note on about implicit state when comparing TypeMirrors (Enhancement - P4)

Reviewers

• Attila Szegedi (@szegedi - Reviewer)
• Vicente Romero (@vicente-romero-oracle - Reviewer)
• Jan Lahoda (@lahodaj - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/29153/head:pull/29153
$ git checkout pull/29153

Update a local copy of the PR:
$ git checkout pull/29153
$ git pull https://git.openjdk.org/jdk.git pull/29153/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 29153

View PR using the GUI difftool:
$ git pr show -t 29153

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/29153.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back darcy! 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]

@jddarcy 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:

8374953: Add note on about implicit state when comparing TypeMirrors

Reviewed-by: attila, vromero, jlahoda

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 10 new commits pushed to the master branch:

• d433ce5: 8369564: Provide a MemorySegment API to read strings with known lengths
• 556bddf: 8372321: TestBackToBackSensitive fails intermittently after JDK-8365972
• 2fbe475: 8374785: Template Library: need to tag Float16.copySign as having non-deterministic result because of multiple NaNs with different sign bits
• ... and 7 more: https://git.openjdk.org/jdk/compare/659b53fe33eaa531bca1951a26f357b51902311e...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.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[openjdk]

@jddarcy The following label will be automatically applied to this pull request:

• compiler

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

[mlbridge]

Webrevs

• 00: Full (a9c803cc)

[szegedi]

Clear and concise!

[vicente-romero-oracle]

lgtm

[lahodaj]

Looks OK to me.

[jddarcy]

/integrate

[openjdk]

Going to push as commit 9a2592f.
Since your change was applied there have been 10 commits pushed to the master branch:

• d433ce5: 8369564: Provide a MemorySegment API to read strings with known lengths
• 556bddf: 8372321: TestBackToBackSensitive fails intermittently after JDK-8365972
• 2fbe475: 8374785: Template Library: need to tag Float16.copySign as having non-deterministic result because of multiple NaNs with different sign bits
• ... and 7 more: https://git.openjdk.org/jdk/compare/659b53fe33eaa531bca1951a26f357b51902311e...master

Your commit was automatically rebased without conflicts.

[openjdk]

@jddarcy Pushed as commit 9a2592f.

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