Re: gcc needs a curly bracket matching/counting function

From	BartC <bc@freeuk.com>
Newsgroups	comp.lang.c
Subject	Re: gcc needs a curly bracket matching/counting function
Date	2016-12-21 00:38 +0000
Organization	A noiseless patient Spider
Message-ID	<o3cirf$619$1@dont-email.me> (permalink)
References	(8 earlier) <4c33eed2-ece9-4616-b274-e0752353b6c2@googlegroups.com> <o3c9fm$3ns$1@dont-email.me> <lna8bqfd0x.fsf@kst-u.example.com> <o3ceb3$o82$1@dont-email.me> <ln1sx2f9c4.fsf@kst-u.example.com>

Show all headers | View raw

On 20/12/2016 23:51, Keith Thompson wrote:
> BartC <bc@freeuk.com> writes:

>> Or, if they have to be taken account of, I would try and cache the
>> results and/or somehow partition the expanded forms of system headers
>> from user code. Since I know that system headers will be debugged, they
>> don't need checking. I will need to determine the likelihood of they
>> containing macros that could inject unbalanced { or } braces into user code.
>
> Macros defined in standard headers can inject unbalanced braces
> indirectly:
>
>     #include <stdint.h>
>     #ifdef UINT64_MAX
>     {
>     #endif
>
> Without processing *all* included headers, preferably the exact same
> headers the user is using, you don't have a 100% solution.

I don't think a solution that is guaranted to 100% match a subsequent 
compile is going to be possible. The brace-checking on a module may be 
done with one compiler and a set of include files, then compiled by 
someone else 6 months later on the other side of the world.

But, are there many instances of debugged, distributed source code 
suddenly failing to compile due to brace-mismatching, even though the 
source has not been touched? And due to the use of macros from the 
standard headers?

I bet that up to now, no one had even considered the possibility!

If I had been thinking of a solution for my own use, I'd only be 
interested in my own code and my own headers; that's why I wasn't too 
bothered about standard headers.

BTW how do smart editors managed it: do they scan the tens of thousands 
of lines of include files, and expand all the macros, in order to be 
able to detect unbalanced braces?

>> Again, that can be checked once, so that if I see #include <windows.h>,
>> I might be able to remember those results without having to
>> re-preprocess it or re-scan the output.
>
> Unless the header is affected by things defined before it's #included.
> <assert.h> is the obvious example.

I was thinking of compile options such as:

   gcc -DABC=1234 program.c

ABC is a macro that might affect how conditional code is compiled.

Then there are things such as __TIME__, which can be different each 
time, although I'm not sure how that would be used to influence 
conditional code. With the use of __LINE__, I can do this:

#if __LINE__ == 10
   #define OPEN {
#else
   #define OPEN }
#endif

Written so that the #if is on line 10, then deleting or inserting any 
line  before that can reverse the definition of OPEN.

-- 
Bartc

Thread

gcc needs a curly bracket matching/counting function DFS <nospam@dfs.com> - 2016-12-19 20:38 -0500
  Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 01:59 +0000
    Re: gcc needs a curly bracket matching/counting function DFS <nospam@dfs.com> - 2016-12-19 22:30 -0500
      Re: gcc needs a curly bracket matching/counting function Robert Spanjaard <spamtrap@arumes.com> - 2016-12-20 11:46 +0100
      Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 13:20 +0000
        Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 13:30 +0000
        Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-20 05:35 -0800
          Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-21 12:07 +0100
            Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 12:46 +0000
              Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-21 15:10 +0100
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 17:10 +0000
                Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-21 19:50 +0100
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 20:15 +0000
                Re: gcc needs a curly bracket matching/counting function Ike Naar <ike@iceland.freeshell.org> - 2016-12-21 22:36 +0000
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 23:46 +0000
                Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-22 01:54 +0000
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-22 12:16 +0000
                Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-22 13:06 +0000
                Re: gcc needs a curly bracket matching/counting function asetofsymbols@gmail.com - 2016-12-22 05:25 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-22 13:34 +0000
                Re: gcc needs a curly bracket matching/counting function asetofsymbols@gmail.com - 2016-12-22 08:16 -0800
                Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-22 09:30 -0800
                Re: gcc needs a curly bracket matching/counting function luser droog <luser.droog@gmail.com> - 2016-12-22 09:40 -0800
                Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-22 05:33 -0800
                Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-22 05:41 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-22 14:53 +0000
                Re: gcc needs a curly bracket matching/counting function asetofsymbols@gmail.com - 2016-12-22 08:11 -0800
                Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-22 08:27 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-22 16:48 +0000
                Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-22 09:27 -0800
                Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-22 20:12 +0000
                Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-22 12:18 -0800
              Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-21 09:04 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 17:24 +0000
                Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-21 09:41 -0800
                Re: gcc needs a curly bracket matching/counting function Ian Collins <ian-news@hotmail.com> - 2016-12-22 18:10 +1300
                Re: gcc needs a curly bracket matching/counting function Ian Collins <ian-news@hotmail.com> - 2016-12-29 14:50 +1300
                Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2017-01-02 02:07 -0800
                Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2017-01-02 11:16 +0100
                Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-28 16:40 -0800
            Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-21 08:52 -0800
              Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-21 20:16 +0100
                Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-22 09:41 +0100
      Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-20 17:04 +0000
        Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 18:46 +0000
          Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-20 21:55 +0000
        Re: gcc needs a curly bracket matching/counting function DFS <nospam@dfs.com> - 2016-12-20 13:52 -0500
          Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 19:09 +0000
          Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 19:14 +0000
            Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 12:16 -0800
              Re: gcc needs a curly bracket matching/counting function Gareth Owen <gwowen@gmail.com> - 2016-12-20 20:53 +0000
                Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 13:51 -0800
                Re: gcc needs a curly bracket matching/counting function Gareth Owen <gwowen@gmail.com> - 2016-12-29 18:49 +0000
                Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-28 16:36 -0800
                Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-29 12:44 +0100
              Re: gcc needs a curly bracket matching/counting function bart4858@gmail.com - 2016-12-20 13:25 -0800
                Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 13:39 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 21:58 +0000
                Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 14:05 -0800
                Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-20 22:17 +0000
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2017-01-26 19:03 +0000
                Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 14:31 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 23:21 +0000
                Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 15:51 -0800
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-21 00:38 +0000
                Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2017-01-26 19:11 +0000
    Re: gcc needs a curly bracket matching/counting function mark.bluemel@gmail.com - 2016-12-20 00:50 -0800
  gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-19 18:11 -0800
    Re: gcc needs a curly bracket matching/counting function fir <profesor.fir@gmail.com> - 2016-12-20 03:00 -0800
      Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 03:50 -0800
        Re: gcc needs a curly bracket matching/counting function fir <profesor.fir@gmail.com> - 2016-12-20 05:20 -0800
    Re: gcc needs a curly bracket matching/counting function DFS <nospam@dfs.com> - 2016-12-20 13:46 -0500
      Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 18:59 +0000
      Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 19:02 +0000
        Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 12:13 -0800
          Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 20:25 +0000
      Re: gcc needs a curly bracket matching/counting function Robert Spanjaard <spamtrap@arumes.com> - 2016-12-20 20:35 +0100
  Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-20 08:56 +0100
  Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 02:26 -0800
    Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 10:41 +0000
      Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 02:52 -0800
        Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 11:00 +0000
          Re: gcc needs a curly bracket matching/counting function Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-20 03:19 -0800
            Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 11:31 +0000
            Re: gcc needs a curly bracket matching/counting function Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-20 17:21 +0000
              Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 17:49 +0000
                Re: gcc needs a curly bracket matching/counting function David Brown <david.brown@hesbynett.no> - 2016-12-21 12:25 +0100
                Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-29 01:14 -0800
    Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 09:07 -0800
      Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 17:14 +0000
        Re: gcc needs a curly bracket matching/counting function Keith Thompson <kst-u@mib.org> - 2016-12-20 09:33 -0800
          Re: gcc needs a curly bracket matching/counting function Richard Heathfield <rjh@cpax.org.uk> - 2016-12-20 17:39 +0000
          Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-20 09:45 -0800
      Re: gcc needs a curly bracket matching/counting function gazelle@shell.xmission.com (Kenny McCormack) - 2016-12-20 17:56 +0000
        Re: gcc needs a curly bracket matching/counting function "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2016-12-20 10:01 -0800
    Re: gcc needs a curly bracket matching/counting function Ian Collins <ian-news@hotmail.com> - 2016-12-21 07:44 +1300
  Re: gcc needs a curly bracket matching/counting function BartC <bc@freeuk.com> - 2016-12-20 10:46 +0000
  Re: gcc needs a curly bracket matching/counting function Ike Naar <ike@iceland.freeshell.org> - 2016-12-20 22:00 +0000
    Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-28 16:39 -0800
  Re: gcc needs a curly bracket matching/counting function Ken Brody <kenbrody@spamcop.net> - 2016-12-22 12:12 -0500
  Re: gcc needs a curly bracket matching/counting function Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2016-12-22 12:59 -0700
  Re: gcc needs a curly bracket matching/counting function Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-28 16:10 -0800

csiph-web