On Mon, 13 Nov 2023 07:46:37 GMT, Jorn Vernee <jver...@openjdk.org> wrote:
>>> For some context: `java.lang.foreign.Linker.nativeLinker().defaultLookup()` >>> returns a `SymbolLookup` that can be used to find symbols from the standard >>> library. >>> >>> We use a shim library that re-exports symbols from the standard library in >>> order to make them accessible through `dlsym`, since on e.g. Linux the >>> standard library .so files might actually be linker scripts which we don't >>> want to mess with. On Windows we use ucrtbase.dll + an auxiliary library >>> that contains the expansions of several 'inline' functions such as >>> `printf`. I'm not surprised to see that another platform like AIX requires >>> more to make this work as well. >>> >>> That said, I think we should limit the exported symbols to only those found >>> in the standard C library header files: >>> https://en.cppreference.com/w/c/header >> >> Currently the symbols are restricted to some parts of libc and the entire >> math library libm. >> Are you suggesting we restrict the list to common math functions such as >> https://en.cppreference.com/w/c/numeric/math ? > >> > That said, I think we should limit the exported symbols to only those >> > found in the standard C library header files: >> > https://en.cppreference.com/w/c/header >> >> Currently the symbols are restricted to some parts of libc and the entire >> math library libm. Are you suggesting we restrict the list to common math >> functions such as https://en.cppreference.com/w/c/numeric/math ? > > I'm suggesting to include things that are defined by the C standard, plus > some platform specific extensions. i.e. limit this to what is considered part > of the public/supported API of the standard library on AIX. @JornVernee when I googled for "dlsym equivalent for static libraries it turned up BFD: https://stackoverflow.com/questions/10279693/dlsym-like-behaviour-for-static-linked-libraries https://ftp.gnu.org/old-gnu/Manuals/bfd-2.9.1/html_chapter/bfd_1.html but it seems ancient. Maybe AIX, given it seems to like/prefer static linking, also provides some tools in this area? ------------- PR Comment: https://git.openjdk.org/jdk/pull/16414#issuecomment-1809550596
