RFR: 8268611: jar --validate should check targeted classes in MR-JAR files

[Jorn Vernee]

On Thu, 14 Nov 2024 11:57:52 GMT, Christian Stein <cstein at openjdk.org> wrote:

> Please review this change ensuring all targeted classes in a MR-JAR file should target the same or a lower classfile version.
> 
> For example, having compiled source files with `javac` 25 without using the `--release` option (or with `--release 25`) and trying to archive them via a `jar --create --file a.jar --release 9 ... --release 10 ...` command now fails with:
> 
> classfile release value of META-INF/versions/9/version/Version.class too high: 25
> classfile release value of META-INF/versions/10/version/Version.class too high: 25
> invalid multi-release jar file a.jar deleted
> 
> 
> This pull request contains fixes to existing tests which produced invalid MR-JAR files. Most of those fixes are achieved by adding an appropriate `--release N` option to the associated `javac` call. One of those fixes rewrites the classfile version bytes between the `javac` and `jar` calls.

src/jdk.jartool/share/classes/sun/tools/jar/resources/jar.properties line 94:

> 92:         unexpected versioned entry {0} for release {1}
> 93: error.release.value.toohigh.versioned.entry=\
> 94:         classfile release value of {0} too high: {1}

Not sure about the term 'release value' here. Is that defined somewhere?

Maybe leaning on 'class file major version' like this would work better?

Suggestion:

error.release.value.toohigh.versioned.entry=\
        class file {0} targeting version '{1}' must have a major version lower or equal to '{2}' , but was '{3}'


And then `{0}` is the entry, `{1}` is the `mrversion`, `{2}` is the class file major version associated with that `mrversion`, and `{3}` was the actual class file major version.

(also, 'class file' is two words)

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PR Review Comment: https://git.openjdk.org/jdk/pull/22103#discussion_r1882289038