cperl

> Rust code that type-puns an unaligned pointer into an integer would crash on MIPS or SPARC just like the C code would. Actually you can enforce that on Intel too. I do that for some hash functions in debugging mode, to avoid valgrind slowdown. e.g. https://github.com/perl11/cperl/blob/master/cpan/Digest-MD5/... #if defined(U32_ALIGNMENT_REQUIRED) && defined(__GNUC__) && (defined(__x86_64__) || defined(__i386)) /* Generate SIGBUS on unaligned access even on x86: Set AC in EFLAGS. See http://orchistro.tistory.com/206 Also see https://sourceforge.net/p/predef/wiki/Architectures/ for possible other compilers. Here only GNU C: gcc, clang, icc. MSVC would be nice also. */ #ifdef __x86_64__ __asm__("pushf\n" "orl $0x40000, (%rsp)\n" "popf");

Interestingly Emacs is not the only project affected by this glibc/dumper dispute. I added the stone-old patches for perl to my cperl fork, to be able to dump/compile perl scripts to native binaries the fast way. Improved dumpers are here: https://github.com/perl11/cperl/commits/feature/gh176-unexec Mostly unified error handling and a few darwin segment instabilities. It is very fragile to use with a static library, but ok as dynamic library. Emacs uses the dumper in the main exe, not in a library. Solaris is the easiest to use. So I know a little bit of the troubles they are talking about here. Dan's portable dumper would be nice to have, XEmacs had this decades ago, but it never made it over to Stallman emacs. Wonder why :) So looking at the new pdump, it really is horrible. I don't think I want to do that. I'll rather add a proper stat

I worked with this recently. This feature is not a nightmare, just because the author doesn't understand what a linker does, and the necessary separation of old and new dynamic memory. It's rather a stable and very useful feature, which just recently got under attack, because glibc doesn't want to maintain malloc_get_state() / malloc_set_state() anymore. XEmacs has a portable dumper pdump, which is a hack compared to emacs unexec. See https://lwn.net/Articles/673724/ and esp. https://lwn.net/Articles/673815/ I recently re-added unexec support (i.e. native compilation) to perl5 in my cperl fork, but I haven't got it stable yet. Super trivial on solaris, but not so easy on elf, darwin and windows with its various compilers and the different way to treat their segments. But it's still the easiest way to do it, compared to pdump or a seperate