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Groups > comp.lang.c > #129859
| Newsgroups | comp.lang.c |
|---|---|
| Date | 2018-04-27 09:26 -0700 |
| References | (3 earlier) <29063935-b373-4307-be80-78a64134d0e7@googlegroups.com> <hve1ed93b184siupcu3cq1sgp8b37tg3fb@4ax.com> <lnpo2ngojj.fsf@kst-u.example.com> <kfnefj0n0uk.fsf@x-alumni2.alumni.caltech.edu> <lnbme4fx2t.fsf@kst-u.example.com> |
| Message-ID | <f173293f-ce83-4229-aa21-e326c24e37b3@googlegroups.com> (permalink) |
| Subject | Re: gcc_centric C code |
| From | supercat@casperkitty.com |
On Friday, April 27, 2018 at 11:12:04 AM UTC-5, Keith Thompson wrote:
> Tim Rentsch <txr@alumni.caltech.edu> writes:
> > Keith Thompson <kst-u@mib.org> writes:
> >> Robert Wessel <robertwessel2@yahoo.com> writes:
> >>> [contrasting __func__ and string-literal predefined macros]
> >>
> >> A very minor point: values yielded by __func__ can be compared for
> >> pointer equality.
> >
> > So can values of string-literal predefined macros.
>
> Can be *meaningfully* compared. This:
>
> printf("%d\n", __FILE__ == __FILE__);
>
> could print either 0 or 1. The value of __func__ for a given
> non-inline function is always the same.
Would moving string concatenation from the preprocessor to the compiler be
an observable change? It would seem desirable to guarantee that the
comparison above would yield true, but not to require that all string
literals with equivalent content must always do so. If concatenation
were allowed to be performed in the compiler, then there would be two
ways for an implementation to guarantee that the above comparison would
always yield true:
1. An implementation could do the concatenation in the preprocessor (as is
currently done) if it guarantees that strings with identical content
will get merged.
2. An implementation could have __FILE expand to a compiler intrinsic
reserved word (e.g. ___FILE) and then have the parsing logic say
that if the system is looking for a literal quote and it sees
___FILE, or if it sees ___FILE followed by a literal quote, then it
will interpret treat the contents of ___FILE as a literal quote that
can be concatenated, but otherwise it will treat it as a static
identifier.
Note that while #2 may be somewhat difficult to describe in a formal
grammar, it would not be particularly difficult to *implement*. Sometimes
the Standard gets too hung up with trying to specify things as formal
grammars, without recognizing that not all useful constructs should be
expected to fit that mold.
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gcc_centric C code bartc <bc@freeuk.com> - 2018-04-25 16:21 +0100
gcc_centric C code Chad <cdalten@gmail.com> - 2018-04-25 08:34 -0700
Re: gcc_centric C code Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-04-25 16:41 +0100
Re: gcc_centric C code Spiros Bousbouras <spibou@gmail.com> - 2018-04-25 16:19 +0000
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-25 18:02 +0100
Re: gcc_centric C code Nick Bowler <nbowler@draconx.ca> - 2018-04-25 17:15 +0000
Re: gcc_centric C code Robert Wessel <robertwessel2@yahoo.com> - 2018-04-25 12:33 -0500
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-25 20:51 +0100
Re: gcc_centric C code supercat@casperkitty.com - 2018-04-25 13:01 -0700
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-25 21:21 +0100
Re: gcc_centric C code jameskuyper@verizon.net - 2018-04-25 13:45 -0700
Re: gcc_centric C code Spiros Bousbouras <spibou@gmail.com> - 2018-04-25 17:20 +0000
Re: gcc_centric C code supercat@casperkitty.com - 2018-04-25 10:30 -0700
Re: gcc_centric C code Robert Wessel <robertwessel2@yahoo.com> - 2018-04-25 12:35 -0500
Re: gcc_centric C code Keith Thompson <kst-u@mib.org> - 2018-04-25 10:54 -0700
Re: gcc_centric C code Philipp Klaus Krause <pkk@spth.de> - 2018-04-25 20:27 +0200
Re: gcc_centric C code Keith Thompson <kst-u@mib.org> - 2018-04-25 12:38 -0700
Re: gcc_centric C code Robert Wessel <robertwessel2@yahoo.com> - 2018-04-25 19:53 -0500
Re: gcc_centric C code Keith Thompson <kst-u@mib.org> - 2018-04-25 18:13 -0700
Re: gcc_centric C code Nick Bowler <nbowler@draconx.ca> - 2018-04-26 15:16 +0000
Re: gcc_centric C code Tim Rentsch <txr@alumni.caltech.edu> - 2018-04-27 08:17 -0700
Re: gcc_centric C code Philipp Klaus Krause <pkk@spth.de> - 2018-04-26 08:03 +0200
Re: gcc_centric C code Nick Bowler <nbowler@draconx.ca> - 2018-04-26 14:30 +0000
Re: gcc_centric C code jameskuyper@verizon.net - 2018-04-26 08:26 -0700
Re: gcc_centric C code Philipp Klaus Krause <pkk@spth.de> - 2018-04-26 19:04 +0200
Re: gcc_centric C code Ian Collins <ian-news@hotmail.com> - 2018-04-27 07:48 +1200
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-26 21:08 +0100
Re: gcc_centric C code Ian Collins <ian-news@hotmail.com> - 2018-04-27 08:18 +1200
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-26 21:44 +0100
Re: gcc_centric C code Ian Collins <ian-news@hotmail.com> - 2018-04-27 09:01 +1200
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-26 23:16 +0100
Re: gcc_centric C code Ian Collins <ian-news@hotmail.com> - 2018-04-27 10:27 +1200
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-26 23:48 +0100
Re: gcc_centric C code Ian Collins <ian-news@hotmail.com> - 2018-04-27 20:41 +1200
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-27 11:51 +0100
Re: gcc_centric C code Ian Collins <ian-news@hotmail.com> - 2018-04-28 07:32 +1200
Re: gcc_centric C code Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-28 04:34 -0700
Re: gcc_centric C code Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-26 23:05 -0700
Re: gcc_centric C code jacobnavia <jacob@jacob.remcomp.fr> - 2018-04-27 00:52 +0200
Re: gcc_centric C code supercat@casperkitty.com - 2018-04-26 16:23 -0700
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-28 11:24 +0100
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-28 01:42 +0100
Re: gcc_centric C code Dan Purgert <dan@djph.net> - 2018-04-26 21:40 +0000
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-26 23:34 +0100
Re: gcc_centric C code "Chris M. Thomasson" <invalid_chris_thomasson@invalid.invalid> - 2018-04-26 14:13 -0700
Re: gcc_centric C code "Chris M. Thomasson" <invalid_chris_thomasson@invalid.invalid> - 2018-04-26 14:16 -0700
Re: gcc_centric C code Tim Rentsch <txr@alumni.caltech.edu> - 2018-04-27 08:08 -0700
Re: gcc_centric C code Keith Thompson <kst-u@mib.org> - 2018-04-27 09:11 -0700
Re: gcc_centric C code supercat@casperkitty.com - 2018-04-27 09:26 -0700
Re: gcc_centric C code Tim Rentsch <txr@alumni.caltech.edu> - 2018-04-27 09:49 -0700
Re: gcc_centric C code supercat@casperkitty.com - 2018-04-25 12:31 -0700
Re: gcc_centric C code Nick Bowler <nbowler@draconx.ca> - 2018-04-25 20:13 +0000
Re: gcc_centric C code supercat@casperkitty.com - 2018-04-25 13:50 -0700
Re: gcc_centric C code Nick Bowler <nbowler@draconx.ca> - 2018-04-25 18:02 +0000
Re: gcc_centric C code Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-25 22:39 -0700
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-25 18:36 +0100
Re: gcc_centric C code Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-04-25 23:15 +0100
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-26 02:02 +0100
Re: gcc_centric C code Keith Thompson <kst-u@mib.org> - 2018-04-25 18:28 -0700
Re: gcc_centric C code Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-04-26 11:45 +0100
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-26 14:53 +0100
Re: gcc_centric C code Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-04-26 23:38 +0100
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-27 00:31 +0100
Re: gcc_centric C code Ben Bacarisse <ben.usenet@bsb.me.uk> - 2018-04-27 00:47 +0100
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-27 02:28 +0100
Re: gcc_centric C code Thiago Adams <thiago.adams@gmail.com> - 2018-04-27 03:44 -0700
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-05-03 13:57 +0100
Re: gcc_centric C code Thiago Adams <thiago.adams@gmail.com> - 2018-05-03 11:02 -0700
Re: gcc_centric C code Thiago Adams <thiago.adams@gmail.com> - 2018-05-03 11:07 -0700
Re: gcc_centric C code Steven Petruzzellis <frelwizzen@gmail.com> - 2018-05-03 11:13 -0700
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-05-03 19:50 +0100
Re: gcc_centric C code Thiago Adams <thiago.adams@gmail.com> - 2018-05-03 13:37 -0700
Re: gcc_centric C code Thiago Adams <thiago.adams@gmail.com> - 2018-05-03 13:44 -0700
Re: gcc_centric C code Thiago Adams <thiago.adams@gmail.com> - 2018-05-11 10:25 -0700
Re: gcc_centric C code Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-26 07:01 -0700
Re: Clearly everyone else likes to do things the hard way Noob <root@127.0.0.1> - 2018-04-26 14:51 +0200
Re: Clearly everyone else likes to do things the hard way mark.bluemel@gmail.com - 2018-04-26 07:09 -0700
Re: Clearly everyone else likes to do things the hard way gazelle@shell.xmission.com (Kenny McCormack) - 2018-04-26 17:05 +0000
Re: Clearly everyone else likes to do things the hard way bartc <bc@freeuk.com> - 2018-04-26 18:38 +0100
Re: Clearly everyone else likes to do things the hard way 1alvinalbrecht1@gmail.com - 2018-04-26 11:34 -0700
Re: Clearly everyone else likes to do things the hard way bartc <bc@freeuk.com> - 2018-04-26 21:36 +0100
Re: Clearly everyone else likes to do things the hard way C W Rose <cwr@seckford.org> - 2018-04-27 19:23 +0100
Re: Clearly everyone else likes to do things the hard way bartc <bc@freeuk.com> - 2018-04-28 14:34 +0100
Re: Clearly everyone else likes to do things the hard way Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-28 10:32 -0700
Re: Clearly everyone else likes to do things the hard way supercat@casperkitty.com - 2018-04-30 10:16 -0700
Re: Clearly everyone else likes to do things the hard way bartc <bc@freeuk.com> - 2018-04-30 19:41 +0100
Re: Clearly everyone else likes to do things the hard way supercat@casperkitty.com - 2018-04-30 12:11 -0700
Re: Clearly everyone else likes to do things the hard way scott@slp53.sl.home (Scott Lurndal) - 2018-04-30 19:14 +0000
Re: Clearly everyone else likes to do things the hard way scott@slp53.sl.home (Scott Lurndal) - 2018-04-30 19:12 +0000
Re: Clearly everyone else likes to do things the hard way bartc <bc@freeuk.com> - 2018-04-30 21:19 +0100
Re: Clearly everyone else likes to do things the hard way Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-30 19:23 -0700
Re: Clearly everyone else likes to do things the hard way Philipp Klaus Krause <pkk@spth.de> - 2018-04-26 19:45 +0200
Re: gcc_centric C code luser droog <luser.droog@gmail.com> - 2018-04-25 21:56 -0700
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-26 11:06 +0100
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-26 11:27 +0100
Re: gcc_centric C code antispam@math.uni.wroc.pl - 2018-04-26 17:00 +0000
Re: gcc_centric C code Thiago Adams <thiago.adams@gmail.com> - 2018-04-25 09:26 -0700
Re: gcc_centric C code Jorgen Grahn <grahn+nntp@snipabacken.se> - 2018-04-26 12:39 +0000
Re: gcc_centric C code gazelle@shell.xmission.com (Kenny McCormack) - 2018-04-26 13:09 +0000
Re: gcc_centric C code Wouter Verhelst <w@uter.be> - 2018-04-26 13:26 +0200
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-26 18:03 +0100
Re: gcc_centric C code Steven Petruzzellis <frelwizzen@gmail.com> - 2018-04-26 14:32 -0700
Re: gcc_centric C code Tim Rentsch <txr@alumni.caltech.edu> - 2018-04-27 09:41 -0700
Re: gcc_centric C code bartc <bc@freeuk.com> - 2018-04-27 19:37 +0100
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