RFR: 8308293: A linker should expose the layouts it supports [v3]

[Paul Sandoz]

On Fri, 19 May 2023 11:08:10 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> This patch adds an instance method on `Linker`, namely `Linker::canonicalLayouts` which returns all the layouts known by the linker as implementing some ABI type. For instance, if I call this on my machine (Linux/x64) I get this:
>> 
>> 
>> jshell> import java.lang.foreign.*;
>> 
>> jshell> Linker.nativeLinker().canonicalLayouts()
>> $2 ==> {char16_t=c16, int8_t=b8, long=j64, size_t=j64, bool=z8, int=i32, long long=j64, int64_t=j64, void*=a64, float=f32, char=b8, int16_t=s16, int32_t=i32, short=s16, double=d64}
>> 
>> 
>> This can be useful to discover the ABI types supported by a linker implementation, as well as for, in the future, add support for more exotic (and platform-dependent) linker types, such as `long double` or `complex long`.
>
> Maurizio Cimadamore has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Address review comments
>  - More javadoc tweaks

src/java.base/share/classes/java/lang/foreign/Linker.java line 62:

> 60:  * </ul>
> 61:  * A linker provides a way to lookup up the <em>canonical layouts</em> associated with the data types used by the ABI.
> 62:  * For example, the canonical layout for the C {@code size_t} type is equal to {@link ValueLayout#JAVA_LONG}. The canonical

Suggestion:

 * For example, the canonical layout for the C {@code size_t} type is equal to {@link ValueLayout#JAVA_LONG} on 64-bit platforms. The canonical

?

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/14037#discussion_r1199471895