Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.c > #101289
| From | BartC <bc@freeuk.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Macro Expansion |
| Date | 2017-01-08 13:10 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <o4tdl4$1k5$1@dont-email.me> (permalink) |
| References | <o4rcbl$4cp$1@dont-email.me> <878tqlykwg.fsf@news.bourguet.org> |
On 08/01/2017 09:13, Jean-Marc Bourguet wrote:
> BartC <bc@freeuk.com> writes:
>
>> I've knocked up a short script program to implement CPP macro expansion. It
>> works with many of the examples I've tried, but I have little confidence
>> that whatever I end up with will always work, as I'm guessing at the
>> algorithms needed.
>>
>> The descriptions I've seen of the process seem to me ambiguous and
>> difficult to understand (maybe they're striving to be as cryptic as the
>> language they are describing!).
>
> Have you looked at the latest standard?
I use one for 201x dated 2009.
I just looked at C90, C99 and C11
> and it seems to be improving. For instance they make clear that given the
> following macro definitions:
>
> #define f(a) a*g
> #define g(a) f(a)
> #define h(a) a*h
>
> the invocation
>
> f(2)(9)
I didn't even know you could do this! This is a simpler example:
#define a b
#define b(x) x x x
a(10)
Result then needs to be 10 10 10.
Then is taken care of if 'a(10)' is part of a replacement token list
being substituted then rescanned for macros.
But 'a(10)' can also be part of normal code, not inside a macro
definition. Then the 'b' that is generated is in a different
'token-space' from the "(10)" in the rest of the file (and likely to
still exist as characters not tokens). Rescanning an entirely source
file is hopelessly inefficient just for the off-chance someone might be
using such macros.
That's going to mean some very untidy logic.
--
Bartc
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Macro Expansion BartC <bc@freeuk.com> - 2017-01-07 18:35 +0000
Re: Macro Expansion Thiago Adams <thiago.adams@gmail.com> - 2017-01-07 11:23 -0800
Re: Macro Expansion Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-07 21:28 +0000
Re: Macro Expansion Siri Cruise <chine.bleu@yahoo.com> - 2017-01-07 11:45 -0800
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-07 20:16 +0000
Re: Macro Expansion Siri Cruise <chine.bleu@yahoo.com> - 2017-01-07 12:23 -0800
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-07 20:31 +0000
Re: Macro Expansion Siri Cruise <chine.bleu@yahoo.com> - 2017-01-07 12:42 -0800
Re: Macro Expansion Ian Collins <ian-news@hotmail.com> - 2017-01-08 14:42 +1300
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-08 13:18 +0000
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-07 20:15 +0000
Re: Macro Expansion Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-07 20:42 +0000
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-07 22:50 +0000
Re: Macro Expansion Ian Collins <ian-news@hotmail.com> - 2017-01-08 11:59 +1300
Re: Macro Expansion Malcolm McLean <malcolm.mclean5@btinternet.com> - 2017-01-07 15:10 -0800
Re: Macro Expansion supercat@casperkitty.com - 2017-01-07 17:24 -0800
Re: Macro Expansion Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-15 21:55 -0800
Re: Macro Expansion supercat@casperkitty.com - 2017-01-16 09:06 -0800
Re: Macro Expansion Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-31 08:51 -0800
Re: Macro Expansion supercat@casperkitty.com - 2017-01-31 13:06 -0800
Re: Macro Expansion Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-03 07:49 -0800
Re: Macro Expansion supercat@casperkitty.com - 2017-02-03 12:03 -0800
Re: Macro Expansion Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-09 09:00 -0800
Re: Macro Expansion Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-08 01:37 +0000
Re: Macro Expansion Jean-Marc Bourguet <jm@bourguet.org> - 2017-01-08 10:22 +0100
Re: Macro Expansion Thiago Adams <thiago.adams@gmail.com> - 2017-01-07 12:18 -0800
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-07 20:28 +0000
Re: Macro Expansion Thiago Adams <thiago.adams@gmail.com> - 2017-01-07 12:36 -0800
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-07 22:59 +0000
Re: Macro Expansion Thiago Adams <thiago.adams@gmail.com> - 2017-01-08 00:20 -0800
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-08 13:30 +0000
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-10 14:00 +0000
Re: Macro Expansion Thiago Adams <thiago.adams@gmail.com> - 2017-01-10 07:43 -0800
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-10 17:47 +0000
Re: Macro Expansion Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-01-10 22:49 +0000
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-10 23:28 +0000
Re: Macro Expansion "James R. Kuyper" <jameskuyper@verizon.net> - 2017-01-10 18:51 -0500
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-11 00:06 +0000
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-10 20:30 +0000
Re: Macro Expansion Thiago Adams <thiago.adams@gmail.com> - 2017-04-26 10:04 -0700
Re: Macro Expansion Keith Thompson <kst-u@mib.org> - 2017-04-26 12:00 -0700
Re: Macro Expansion Thiago Adams <thiago.adams@gmail.com> - 2017-04-26 12:24 -0700
Re: Macro Expansion bartc <bc@freeuk.com> - 2017-04-26 20:12 +0100
Re: Macro Expansion Thiago Adams <thiago.adams@gmail.com> - 2017-04-26 12:34 -0700
Re: Macro Expansion jameskuyper@verizon.net - 2017-04-26 13:46 -0700
Re: Macro Expansion Jean-Marc Bourguet <jm@bourguet.org> - 2017-01-08 10:13 +0100
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-08 13:10 +0000
Re: Macro Expansion Jean-Marc Bourguet <jm@bourguet.org> - 2017-01-08 15:51 +0100
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-08 17:17 +0000
Re: Macro Expansion supercat@casperkitty.com - 2017-01-08 11:04 -0800
Re: Macro Expansion Malcolm McLean <malcolm.mclean5@btinternet.com> - 2017-01-08 11:10 -0800
Re: Macro Expansion supercat@casperkitty.com - 2017-01-08 14:08 -0800
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-08 19:49 +0000
Re: Macro Expansion supercat@casperkitty.com - 2017-01-08 14:17 -0800
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-08 19:19 +0000
Re: Macro Expansion Jean-Marc Bourguet <jm@bourguet.org> - 2017-01-08 21:43 +0100
Re: Macro Expansion supercat@casperkitty.com - 2017-01-08 10:43 -0800
Re: Macro Expansion Keith Thompson <kst-u@mib.org> - 2017-01-08 12:39 -0800
Re: Macro Expansion antispam@math.uni.wroc.pl - 2017-01-08 22:54 +0000
Re: Macro Expansion "James R. Kuyper" <jameskuyper@verizon.net> - 2017-01-08 18:36 -0500
Re: Macro Expansion antispam@math.uni.wroc.pl - 2017-01-09 01:15 +0000
Re: Macro Expansion "James R. Kuyper" <jameskuyper@verizon.net> - 2017-01-08 20:49 -0500
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-08 23:53 +0000
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-09 01:11 +0000
Re: Macro Expansion antispam@math.uni.wroc.pl - 2017-01-09 01:31 +0000
Re: Macro Expansion BartC <bc@freeuk.com> - 2017-01-10 11:28 +0000
csiph-web