[lworld] RFR: 8372515: [lworld] Plumb in javac flags for compiling with preview mode [v2]

[David Beaumont]

On Wed, 10 Dec 2025 10:51:06 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> David Beaumont has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Remove note about StableValue (not possible)
>
> src/jdk.compiler/share/classes/com/sun/tools/javac/file/Locations.java line 1:
> 
>> 1: /*
> 
> Most of the changes in this files are stylistic. I'd strongly recommend (in the future) to separate those out, so that the "meat" of the PR is more self-evident. After all, filing multiple PRs is cheap :-)

Oh, for some reason it's got the reformatted version of the file I use for editing, not the "minimal diff" version I normally push. I can undo that. Sorry.

> src/jdk.compiler/share/classes/com/sun/tools/javac/file/Locations.java line 151:
> 
>> 149: 
>> 150:     private void addCloseable(Closeable c) {
>> 151:         synchronized (closeables) {
> 
> Here and elsewhere -- I'm not sure about `synchronized`. In general, javac operates under the assumption of "single threaded-ness" -- but I see around the file manager code that `synchronized` seems to be used. I'll leave this to @lahodaj

I think in the compiler you can't assume single threaded-ness, and unless this adds a deadlock risk (which I am pretty sure it doesn't) it's definitely my preference to have correctness and avoid weird bugs/failures.

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PR Review Comment: https://git.openjdk.org/valhalla/pull/1761#discussion_r2619986996
PR Review Comment: https://git.openjdk.org/valhalla/pull/1761#discussion_r2619992479