On Tue, 18 Apr 2023 13:45:57 GMT, Jorn Vernee <jver...@openjdk.org> wrote:
>> This patch adds checks in AbstractLinker to reject packed structs and >> structs with excess padding (e.g. unnamed bitfields), since both of those >> are currently not supported, and the ABI/spec seems too vague to base >> support on. > > Jorn Vernee has updated the pull request with a new target base due to a > merge or a rebase. The incremental webrev excludes the unrelated changes > brought in by the merge/rebase. The pull request contains seven additional > commits since the last revision: > > - fix TestIllegalLink > - Merge branch 'PR_21' into RejectPacked > - Merge branch 'PR_21' into RejectPacked > - add javadoc + fixes for trailing padding > - fix check for padding. Add check for trailing padding too > - Reject packed structs and structs with extra padding > - Check byte order of layouts passed to linker src/java.base/share/classes/java/lang/foreign/Linker.java line 202: > 200: * Due to limited ABI specification coverage, all the native linker > implementations limit the function > 201: * descriptors that they support to those that contain only so-called > <em>canonical</em> layouts. These layouts > 202: * have the following restrictions: I think it's better to phrase this more or less as: A canonical layout has the following characteristics: * Its alignment constraint is equal to its natural alignment * If the layout is a value layout (linkplain), its byte order matches that of the platform in which the JVM is executing (link to nativeOrder()) * If the layout is a group layout (linkplain), it must not contain more padding layout (linkplain) elements than those strictly necessary to satisfy the alignment constraints of the non-padding elements of the group layout. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/13164#discussion_r1170624323
