On Wed, 17 May 2023 18:18:03 GMT, Maurizio Cimadamore <mcimadam...@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 one > additional commit since the last revision: > > Tweak javadoc > I don't see `char16_t` defined either and i believe that type is an alias for > `uint_least16_t`, which is a type of _at least_ 16 bits. We need to use a C > type of `unsigned short` or `uint16_t`: > > * Java `ValueLayout.JAVA_SHORT` <-> C `short` > > * Java `ValueLayout.JAVA_CHAR` <-> C `unsigned short` > > > ? Good point on "unsigned short". > > For canonical type names we may want to prefer types specified by the C > language over those defined by the C library in standard headers? Yes, I think better to stick with standard C types - IMHO with the exception of size_t which is very ubiquitous. ------------- PR Comment: https://git.openjdk.org/jdk/pull/14037#issuecomment-1553609560