Am Mittwoch, dem 13.10.2021 um 15:21 +0000 schrieb Michael Matz: > Hello, > > On Wed, 13 Oct 2021, Martin Uecker wrote: > > > does anybody know if all architectures support passing > > an environment pointer in their function call ABI? > ... > > Or you could mean what normally would be called 'static chain', i.e. > a pointer to the stack frame of outer functions for languages > supporting nested functions. I could imagine this also be called > environment.
Yes, sorry for not being clear. It is sometimes called environment pointer. > If you mean that, then it's indeed psABI specific, and possibly not > al ABIs specify it (in which case GCC will probably have set a de- > facto standard at least for unixy systems). The x86-64 psABI for > instance does specify a register for this, which is separate from > the normal argument passing registers. Other psABIs could say that > it's passed like a hidden argument prepended to the formal list of > args. > Yes, most architecture seem to define a register. I am wondering if there is a table or summary somewhere. > Or do you mean something else entirely? It might also help to know > the purpose of your question :) > There is currently no standard way to set or query the static chain from C although this is used by many other languages. Also function pointers in C usually can not store the static chain. I am going to propose to WG14 to add some kind of wide function pointer to address this. I am doing back ground research to understand whether this exists everywhere. Martin
