On Sun, 14 May 2023, 11:21 Jonathan Wakely, <jwakely....@gmail.com> wrote:
> > > On Sun, 14 May 2023, 10:47 David Brown, <david.br...@hesbynett.no> wrote: > >> On 14/05/2023 07:38, Po Lu via Gcc wrote: >> >> > No, all you have to do is to tell GNU CC to compile Standard C. But >> > what's being debated here is the behavior of GNU CC when translating >> > both Standard C and GNU C, so your demonstration is almost completely >> > pointless. >> > >> You keep using the term "Standard C", but you are using it incorrectly. >> >> "Standard C" means "The language C as recognised by standardisation >> bodies". It is, currently, ISO/IEC 9899:2018 - also known as C17/C18. >> (The standard was completed in C17, but not actually published until C18.) >> >> If you want to refer to older standards (or unpublished future >> standards), you should do so explicitly - C90, C99, C11, C23. >> >> Then there are "extended standards" - specific documented extensions on >> top of an official standard. "gnu17" would be an example of that. >> >> Any language from before the first ANSI C is /not/ standard, since it is >> not based on any standards document. The nearest would be the de-facto >> "standard" (anything "de-facto" is, by definition, not an actual >> standard) language described in the first edition of "The C Programming >> Language", and known as "K&R C". Many of the C compilers of that time >> followed the book and implemented - modulo bugs, extensions, >> inconsistencies, and missing features - the language "K&R C". Many also >> had their own variants, as "C" was already popular before the book was >> published. >> >> >> So - if you are referring to "K&R C", then use that term. It is quite >> well defined, and accurately describes a popular pre-standard C language. >> >> And you may note that if you look at the GCC manual, it supports all >> standards of C (at least as closely as possible). All /standards/. >> "K&R C" is not a standard, and not officially supported by GCC - there >> has never, to my knowledge, been any kind of guarantee that GCC would >> support pre-standard syntax. > > > > There used to be the -traditional option which was deprecated in gcc 3.1 > and removed in gcc 3.3 > > https://gcc.gnu.org/gcc-3.1/changes.html > https://gcc.gnu.org/gcc-3.3/changes.html > But even as far back as gcc 2.95.3 that was documented only to "attempt" to support "some" features of pre -standard C: "Attempt to support some aspects of traditional C compilers." > > There has only been a guarantee that >> appropriate choices of flags would cause pre-standard syntax to be >> detected and rejected or diagnosed. Ironically, the discussion here, >> with its suggestions of explicit flags to allow "K&R C" constructs, has >> come closer to guaranteeing support for that pre-standard dialect than >> GCC has ever had before. >> >> <https://gcc.gnu.org/onlinedocs/gcc/Standards.html> >> <https://gcc.gnu.org/onlinedocs/gcc/C-Dialect-Options.html> >> >> >> >> >> (When people refer to "ANSI C", they almost invariably mean the ANSI >> standard from 1989 that formed, after a bit of section renumbering, ISO >> C90, it is worth remembering that ANSI actually delegates the C >> standardisation to ISO. So "ANSI C" refers to the same language as >> C17/C18.) >> >> >>
