On Fri, 27 Oct 2023 11:35:54 GMT, Jan Lahoda <jlah...@openjdk.org> wrote:
> Consider a simple module, like:
>
> module test {}
>
>
> And compile it with JDK 22 and JDK 21 using:
> javac --release 21
>
> The results of the compilations will differ: when compiling with JDK 21, the
> mandated java.base dependency will get a version, possibly like
> "21-internal". When compiling with JDK 22, the version of the java.base
> dependency will be empty.
>
> This is a) because `module-info.class`es in `ct.sym` do not have any module
> version set; b) for JDK N, `--release N` is not using `ct.sym`, but rather
> `lib/modules`, which may contain a range of version specifiers.
>
> This patch does two changes:
> a) tweaks the `module-info.class`es in `ct.sym`, so that they contain a
> simple version. For `--release N`, the version is `N`.
> b) tweaks the whole build so that `ct.sym` is used always for `--release`, a
> `lib/modules` is never used. I.e. the appropriate classfiles are copied into
> `ct.sym`. This not only allows for a general approach to module versions, but
> simplifies the `--release` handling in javac, and should enable future
> improvements. This is, however, a relatively big change.
>
> The use of `lib/modules` for `--release <current>` was made to improve build
> performance, but the build has been updated since this has been introduced,
> so the slowdown caused by rebuilding `ct.sym` should be much lower now.
>
> With these changes, compiling with `--release N` should record the same
> dependency versions in `module-info` on JDK N and JDK N + 1.
make/modules/jdk.compiler/Gendata.gmk line 101:
> 99:
> 100:
> ################################################################################
> 101:
This too is provided by the framework, and is not needed in these "snippet"
makefiles.
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PR Review Comment: https://git.openjdk.org/jdk/pull/16400#discussion_r1386894723
