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   Dima Pasechnik 🇺🇦 🇳🇱 (dimpase@mathstodon.xyz)'s status on Tuesday, 22-Apr-2025 20:26:41 JST Dima Pasechnik 🇺🇦 🇳🇱

   C23 C language standard made a decision which breaks C functions with arbitrary number of arguments.

   How does one define an *arbitrary* function pointer in C23? (not only variadic, which is a special case)

   https://gitlab.com/embeddable-common-lisp/ecl/-/issues/775

   #c #c23

   • Embed this notice
     Alfred M. Szmidt (amszmidt@mastodon.social)'s status on Tuesday, 22-Apr-2025 20:26:40 JST Alfred M. Szmidt

     in reply to

     @dimpase C doesn’t have arbitrary number of arguments for functions… never really had. A compliant implementation can put a relatively small limit on how many arguments you can actually pass to a function. 👺

   • Embed this notice
     Alfred M. Szmidt (amszmidt@mastodon.social)'s status on Tuesday, 22-Apr-2025 20:42:19 JST Alfred M. Szmidt

     in reply to

     @dimpase And the title is slightly misleading, GCC 15 did not default to -std=c23, it defaults to -std=gnu23 which is slightly different. From https://gcc.gnu.org/gcc-15/changes.html#c

     "C23 by default: GCC 15 changes the default language version for C compilation from -std=gnu17 to -std=gnu23. If your code relies on older versions of the C standard, you will need to either add -std= to your build flags, or port your code; see the porting notes."

     I'd file a regression, GCC 15 is not yet released ...

   • Embed this notice
     Alfred M. Szmidt (amszmidt@mastodon.social)'s status on Wednesday, 23-Apr-2025 05:07:02 JST Alfred M. Szmidt

     in reply to

     @dimpase I know, has there been a upstream bug been reported? I'd consider this a serious regression ... GCC 15 is still frozen, so there is a very small sliver that things might get fixed.

   • Embed this notice
     Dima Pasechnik 🇺🇦 🇳🇱 (dimpase@mathstodon.xyz)'s status on Wednesday, 23-Apr-2025 05:07:04 JST Dima Pasechnik 🇺🇦 🇳🇱

     in reply to

     • Alfred M. Szmidt

     @amszmidt
     the problem is that
     
     void foobar();

     (or perhaps foobar(void)) used to match a function foobar() with any calling convention and any number of arguments. (and similar for function pointers). It could have been implementation-dependent, formally speaking, but given that the most compilers were able to deal with it, no problems arose.

     So 20-30-40 years ago people wrote Lisp compilers (ECL), computer algebra systems, and with minimal changes the code worked from one standard to another. Not any more with c23 or gnu23.

   • Embed this notice
     Dima Pasechnik 🇺🇦 🇳🇱 (dimpase@mathstodon.xyz)'s status on Wednesday, 23-Apr-2025 05:10:16 JST Dima Pasechnik 🇺🇦 🇳🇱

     in reply to

     • Alfred M. Szmidt
     • Sergei Trofimovich

     @amszmidt maybe @trofi knows

   • Embed this notice
     Alfred M. Szmidt (amszmidt@mastodon.social)'s status on Wednesday, 23-Apr-2025 05:13:13 JST Alfred M. Szmidt

     in reply to

     • Sergei Trofimovich

     @dimpase > (or perhaps foobar(void))

     Would have never been valid, the foobar() syntax goes back to K&R C. Which predates `void' by quite a bunch. Back then, if you didn't specify things .. all goes. If I don't remember incorrectly,

     foobar(a,b)
     int a;
     int b;
     int c;
     { ... }

     might have been valid (recall, K&R C did not have variadic ..)

     @trofi

   • Embed this notice
     amen zwa, esq. (amenzwa@mathstodon.xyz)'s status on Wednesday, 23-Apr-2025 05:17:27 JST amen zwa, esq.

     in reply to

     • Alfred M. Szmidt
     • Sergei Trofimovich

     @amszmidt @dimpase @trofi SunOS 4.x, well into the 1990s, came with the 1978 K&R C.

     No "void".

   • Embed this notice
     Alfred M. Szmidt (amszmidt@mastodon.social)'s status on Wednesday, 23-Apr-2025 18:57:37 JST Alfred M. Szmidt

     in reply to

     • 🇺🇦 haxadecimal
     • amen zwa, esq.
     • Lars Brinkhoff
     • Sergei Trofimovich

     @AmenZwa @brouhaha @larsbrinkhoff @dimpase @trofi Regarding void, anyone remember doing "#define void" for compatibility .. mm.. those where the times.

   • Embed this notice
     🇺🇦 haxadecimal (brouhaha@mastodon.social)'s status on Wednesday, 23-Apr-2025 18:57:39 JST 🇺🇦 haxadecimal

     in reply to

     • amen zwa, esq.
     • Lars Brinkhoff
     • Alfred M. Szmidt
     • Sergei Trofimovich

     @larsbrinkhoff @AmenZwa @amszmidt @dimpase @trofi
     What sizes were the integer types?

   • Embed this notice
     amen zwa, esq. (amenzwa@mathstodon.xyz)'s status on Wednesday, 23-Apr-2025 18:57:39 JST amen zwa, esq.

     in reply to

     • 🇺🇦 haxadecimal
     • Lars Brinkhoff
     • Alfred M. Szmidt
     • Sergei Trofimovich

     @brouhaha @larsbrinkhoff @amszmidt @dimpase @trofi

     From K&RC (1978) Appendix A p. 182

   • Embed this notice
     Lars Brinkhoff (larsbrinkhoff@mastodon.sdf.org)'s status on Wednesday, 23-Apr-2025 18:57:40 JST Lars Brinkhoff

     in reply to

     • amen zwa, esq.
     • Alfred M. Szmidt
     • Sergei Trofimovich

     @AmenZwa @amszmidt @dimpase @trofi ITS, well into the 1980s, came with the 1972 pre-K&R C.

   • Embed this notice
     amen zwa, esq. (amenzwa@mathstodon.xyz)'s status on Thursday, 24-Apr-2025 03:19:11 JST amen zwa, esq.

     in reply to

     • 🇺🇦 haxadecimal
     • Lars Brinkhoff
     • Alfred M. Szmidt
     • Vassil Nikolov
     • Sergei Trofimovich

     @vnikolov @larsbrinkhoff @brouhaha @amszmidt @dimpase @trofi

     I was born on a PDP-11/70 running Version 7 and raised on a VAX-11/780 running 4BSD. And although there was a DECsystem-10 in the computer centre, it was run by a small cadre of powerful system administrators and professors, who jealously guarded the monster. We undergrads never got to play with it.

     In fact, I never got to use a 36-biter, because the workstation revolution took hold while I was in college, and the rest, as they say, is RISCtory.

   • Embed this notice
     Vassil Nikolov (vnikolov@ieji.de)'s status on Thursday, 24-Apr-2025 03:19:12 JST Vassil Nikolov

     in reply to

     • 🇺🇦 haxadecimal
     • amen zwa, esq.
     • Lars Brinkhoff
     • Alfred M. Szmidt
     • Sergei Trofimovich

     @AmenZwa @larsbrinkhoff @brouhaha @amszmidt @dimpase @trofi
     PDP-10 doesn't have addressable bytes.

     Alfred M. Szmidt repeated this.
   • Embed this notice
     amen zwa, esq. (amenzwa@mathstodon.xyz)'s status on Thursday, 24-Apr-2025 03:19:13 JST amen zwa, esq.

     in reply to

     • 🇺🇦 haxadecimal
     • Lars Brinkhoff
     • Alfred M. Szmidt
     • Sergei Trofimovich

     @larsbrinkhoff @brouhaha @amszmidt @dimpase @trofi I admire ITS’s fastidious uniformity.😀

   • Embed this notice
     Lars Brinkhoff (larsbrinkhoff@mastodon.sdf.org)'s status on Thursday, 24-Apr-2025 03:19:14 JST Lars Brinkhoff

     in reply to

     • 🇺🇦 haxadecimal
     • amen zwa, esq.
     • Alfred M. Szmidt
     • Sergei Trofimovich

     @brouhaha @AmenZwa @amszmidt @dimpase @trofi With the ITS C compiler, all integer types are 36 bits wide. Yes, even char.

   • Embed this notice
     Alfred M. Szmidt (amszmidt@mastodon.social)'s status on Thursday, 24-Apr-2025 20:56:47 JST Alfred M. Szmidt

     in reply to

     • 🇺🇦 haxadecimal
     • amen zwa, esq.
     • Lars Brinkhoff
     • Vassil Nikolov
     • Sergei Trofimovich

     @vnikolov @brouhaha @AmenZwa @larsbrinkhoff @dimpase @trofi I'm not sure what the confusion is? A byte on the PDP-10 is variable size.

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     🇺🇦 haxadecimal (brouhaha@mastodon.social)'s status on Thursday, 24-Apr-2025 20:56:49 JST 🇺🇦 haxadecimal

     in reply to

     • amen zwa, esq.
     • Lars Brinkhoff
     • Alfred M. Szmidt
     • Vassil Nikolov
     • Sergei Trofimovich

     @vnikolov @AmenZwa @larsbrinkhoff @amszmidt @dimpase @trofi
     The PDP-10 most certainly DOES have addressable bytes. That's the subject of section 2.3 of the System Reference Manual.
     In theory, that was an optional feature of the earliest PDP-10 processor, the KA10, but there is no evidence that DEC ever sold a KA10 without the option.

   • Embed this notice
     Vassil Nikolov (vnikolov@ieji.de)'s status on Thursday, 24-Apr-2025 20:56:49 JST Vassil Nikolov

     in reply to

     • 🇺🇦 haxadecimal
     • amen zwa, esq.
     • Lars Brinkhoff
     • Alfred M. Szmidt
     • Sergei Trofimovich

     @brouhaha @AmenZwa @larsbrinkhoff @amszmidt @dimpase @trofi

     brouhaha@mastodon.social> The PDP-10 most certainly DOES have addressable bytes. That's the subject of section 2.3 of the System Reference Manual.

     I'm just a little bit curious about your definition of _addressable byte_.