On Mon, 1 Jun 2026 09:03:34 GMT, David Simms <[email protected]> wrote:
>> This is a "*sub-review pull request*" for the first >> [preview](https://openjdk.org/jeps/12) of [JEP 401: Value Classes and >> Objects](https://openjdk.org/jeps/401), specifically >> [JDK-8317278](https://bugs.openjdk.org/browse/JDK-8317278): JVM >> implementation of value classes and objects. >> >>> [!NOTE] >>> This pull request and the other sub-review pull requests listed below are >>> based on the "*master pull request*" >>> (https://github.com/openjdk/jdk/pull/31120). It contains the same full set >>> of code changes as the "*master pull request*" to preserve the full >>> implementation context; the language compiler, JVM, and standard library >>> changes are intertwined. This separate pull requests exist only to >>> subdivide the review and related discussion by area. >> >> Other areas for review: >> >> - [JDK-8317277](https://bugs.openjdk.org/browse/JDK-8317277): Java language >> implementation of value classes and objects >> - https://github.com/openjdk/jdk/pull/31121 >> - [JDK-8317279](https://bugs.openjdk.org/browse/JDK-8317279): Standard >> library implementation of value classes and objects >> - https://github.com/openjdk/jdk/pull/31123 >> >> Code changes resulting from the review process should be made in >> [`valhalla/lworld`](https://github.com/openjdk/valhalla/). >> >> `valhalla/lworld` is currently updated from `jdk/master` whenever a weekly >> [`jdk` tag](https://github.com/openjdk/jdk/tags) is created. At that time, >> code changes from `valhalla/lworld` will be propagated to the master pull >> request and to all sub-review pull requests, including this one. >> >> Ultimately, review sign-off will be recorded on the "*master pull request*", >> and this pull request will be closed without integration. >> >> This pull request has a large code surface area and often conflicts with >> `jdk/master` on a daily basis. Refer to >> [`valhalla/lworld`](https://github.com/openjdk/valhalla/) for the latest >> state of the project code, keeping in mind that it may lag several days >> behind `jdk/master`. Both repositories may be needed as references during >> review. >> >> --------- >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > David Simms has updated the pull request with a new target base due to a > merge or a rebase. The pull request now contains 2754 commits: > > - Merge remote-tracking branch 'valhalla/lworld' into > jep401_sub_review_8317278 > - Merge > > Merge jdk-27+24 > - 8385674: [lworld] TestNullableInlineTypes.java fails after JDK-8325632 > > Reviewed-by: mchevalier > - 8385652: [lworld] RedefineClasses should use stack map frame name > > Reviewed-by: fparain > - 8384107: [lworld] Update runtime/contended tests to run the same testing > for value classes > > Reviewed-by: fparain, lmesnik > - 8385600: [lworld] DA/DU issues with strict fields > > Reviewed-by: vromero > - 8384897: [lworld] this.staticField should be restricted in early > construction context > > Reviewed-by: liach, vromero > - 8385601: [lworld] Update testing documentation for the ValueClassPlugin > jtreg option > > Reviewed-by: lmesnik > - 8385569: [lworld] Apply JDK-8343767 to Valhalla specific StubRoutines > > Reviewed-by: fparain, vlivanov > - 8385581: [lworld] Remove the experimental JVMCI feature > 8382708: [lworld] JVMCI support for Value Objects > 8372605: [lworld] > compiler/jvmci/jdk.vm.ci.runtime.test/src/jdk/vm/ci/runtime/test/TestResolvedJava*.java > fail with --enable-preview > > Reviewed-by: thartmann > - ... and 2744 more: https://git.openjdk.org/jdk/compare/2c7efc08...e0250a38 src/hotspot/share/classfile/classLoaderStats.cpp line 42: > 40: return true; > 41: } > 42: return false; Suggestion: return k->is_objArray_klass() && k->kind() != Klass::KlassKind::ObjArrayKlassKind: src/hotspot/share/classfile/fieldLayoutBuilder.cpp line 66: > 64: assert(inline_layout_info_array == nullptr || > 65: > inline_layout_info_array->adr_at(field_info.index())->klass() == nullptr, > 66: "Static fields do not have inline layout info"); Suggestion: assert(inline_layout_info_array == nullptr || inline_layout_info_array->adr_at(field_info.index())->klass() == nullptr, "Static fields do not have inline layout info"); src/hotspot/share/classfile/fieldLayoutBuilder.cpp line 82: > 80: assert(field_info.access_flags().is_strict(), "null-free fields must > be strict"); > 81: if (vk->must_be_atomic()) { > 82: if (vk->is_naturally_atomic(true /* null-free */) && > vk->has_null_free_non_atomic_layout()) return > LayoutKind::NULL_FREE_NON_ATOMIC_FLAT; Suggestion: if (vk->is_naturally_atomic(true /* null-free */) && vk->has_null_free_non_atomic_layout()) { return LayoutKind::NULL_FREE_NON_ATOMIC_FLAT; } src/hotspot/share/classfile/fieldLayoutBuilder.cpp line 91: > 89: // can only be used in containers that have atomicity quarantees > (can_use_atomic_flat argument set to true) > 90: if (field_info.access_flags().is_strict() && > field_info.access_flags().is_final() && can_use_atomic_flat) { > 91: if (vk->has_nullable_non_atomic_layout()) return > LayoutKind::NULLABLE_NON_ATOMIC_FLAT; Suggestion: if (vk->has_nullable_non_atomic_layout()) { return LayoutKind::NULLABLE_NON_ATOMIC_FLAT; } ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/31122#discussion_r3338167612 PR Review Comment: https://git.openjdk.org/jdk/pull/31122#discussion_r3338174042 PR Review Comment: https://git.openjdk.org/jdk/pull/31122#discussion_r3338177378 PR Review Comment: https://git.openjdk.org/jdk/pull/31122#discussion_r3338181572
