gcc_centric C code

Newsgroups	comp.lang.c
From	bartc <bc@freeuk.com>
Subject	gcc_centric C code
Message-ID	<I11EC.8185$oo.4543@fx35.am4> (permalink)
Organization	virginmedia.com
Date	2018-04-25 16:21 +0100

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These are some observations about the difficulties of getting C source 
code to compile, if you try and do it outside the confines of a 
preferred compiler and build system.

I took one github C project and tried to compile all the 48 C files in 
one subdirectory, but without using makefiles or taking any config 
steps. These are the results trying various Windows C compilers:

gcc            47 files compiled successfully out of 48
Tiny C         40 files
Pelles C       32 files
lccwin         17 files
DMC            24 files
MSVC           38 files
bcc (mine)     36 files (after disabling a code-gen bug)

The one problem file for gcc was a missing header that I couldn't find 
anywhere.

Now, maybe this needs to have some configuration to build some config.h 
which will magically make it all work, or maybe not all files are 
relevant for a particular config.

But if you are using a very non-mainstream and bare compiler like mine, 
then that is unlikely to make a difference.

The fact is, that even after bunches of #ifdefs to cater for GNUC and 
MSCVER and whatever, there are still difficulties in getting code to 
compile.

Among the problems I had to solve to get to my 36/48, was the use of 
__func__, something that doesn't seem to be in the C standard, and 
appears to be a predefined macro to give the current function name. OK, 
I had to implement that (but how many dozens of such ad-hoc extensions 
are there?).

Another, was not recognising 'size_t', which was due to a block of code 
like this:

#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
#  include <stdlib.h>
# endif
#endif

#ifdef HAVE_ALLOCA_H
# include <alloca.h>
#elif !defined alloca
# ifdef __GNUC__
#  define alloca __builtin_alloca
# elif defined _AIX
#  define alloca __alloca
# elif defined _MSC_VER
#  include <malloc.h>
#  define alloca _alloca
# elif !defined HAVE_ALLOCA
#  ifdef  __cplusplus
extern "C"
#  endif
void *alloca (size_t);
# endif
#endif

---------------
The problem was that alloca() declaration, that uses size_t, because the 
needed headers are included after this code. This doesn't affect gcc or 
MSVC because they have their own #elif blocks so this isn't seen.

All this I find quite typical of open source C code. It is 
soul-destroying if you're trying to get an implementation to work, and 
that fact that other compilers including MVSC can also have problems, is 
not much comfort.

(And for that reason, I'm retiring my C compiler for use with existing C 
projects as it would be a never-ending task. It will be for new code.)

-- 
bartc

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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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