Re: C++ forcing unnecessary changes to C?

From	David Brown <david.brown@hesbynett.no>
Newsgroups	comp.lang.c
Subject	Re: C++ forcing unnecessary changes to C?
Date	2016-11-22 15:50 +0100
Organization	A noiseless patient Spider
Message-ID	<o11lu5$2t4$1@dont-email.me> (permalink)
References	<o0mseq$e7o$1@dont-email.me> <o115oq$84f$2@dont-email.me> <o118p6$j9q$1@dont-email.me> <o11if4$kqh$2@dont-email.me>

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On 22/11/16 14:51, jacobnavia wrote:
> Le 22/11/2016 à 12:05, David Brown a écrit :
>> So gcc certainly does not generate exception tables for C compilation.
> 
> This is FALSE. See the thread I started "Negative effects of c++ in C".
> For your convenience here is a msg:
> 
> No, I am talking about gcc. For instance I have a program called "asm",
> an assembler, featuring
> 
> jacob@linux-mint ~/lcc/asm/asm4 $ ls -l asm
> -rwxrwxr-x 1 jacob jacob 1462480 Nov 22 14:40 asm
> jacob@linux-mint ~/lcc/asm/asm4 $ objdump -h asm
> 
> asm:     file format elf64-x86-64
> 
> Sections:
> Idx Name          Size
>  0 .interp       0000001c
> ...
> several other small sections elided
> ...
> 15 .eh_frame_hdr 00003734
> 16 .eh_frame     00015b5c
> 
> We have then 0x3734 (14132) and 0x15b5c (88924) bytes, i.e. 103,506
> bytes of exception handling overhead!
> 
> ALL the sources are in straight C and I have to pay 103,506 c++ taxes!
> 
> For NOTHING since C has no throws!

A little research shows that this is a /requirement/ of the x86-64 ABI.
 Amongst other things, gcc also uses it for debugging and cleanup
attributes (a gcc extension allowing a sort of destructor call in C).

On targets that don't have such ABI requirements - such as the ARM that
I am using - there are no exception tables or other C++ related
overhead, other than a few instructions from the library startup code.

Thread

C++ forcing unnecessary changes to C? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 20:34 +0800
  Re: C++ forcing unnecessary changes to C? Thiago Adams <thiago.adams@gmail.com> - 2016-11-18 05:09 -0800
    Re: C++ forcing unnecessary changes to C? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 21:42 +0800
      Re: C++ forcing unnecessary changes to C? jameskuyper@verizon.net - 2016-11-18 11:14 -0800
    Re: C++ forcing unnecessary changes to C? jameskuyper@verizon.net - 2016-11-18 11:10 -0800
      Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-19 15:26 +0100
        Re: C++ forcing unnecessary changes to C? "James R. Kuyper" <jameskuyper@verizon.net> - 2016-11-19 10:09 -0500
          Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-20 13:47 +0100
      Re: C++ forcing unnecessary changes to C? Thiago Adams <thiago.adams@gmail.com> - 2016-11-21 03:25 -0800
        Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-21 14:15 +0100
          Re: C++ forcing unnecessary changes to C? Thiago Adams <thiago.adams@gmail.com> - 2016-11-21 05:39 -0800
  Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 14:26 +0100
    Re: C++ forcing unnecessary changes to C? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 21:41 +0800
      Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 15:20 +0100
        Re: conduct in comp.lang.c "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 22:23 +0800
  Re: C++ forcing unnecessary changes to C? Philipp Klaus Krause <pkk@spth.de> - 2016-11-18 15:16 +0100
    Re: C++ forcing unnecessary changes to C? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 22:20 +0800
      Re: C++ forcing unnecessary changes to C? jameskuyper@verizon.net - 2016-11-18 11:18 -0800
    Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-18 07:15 -0800
      Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 16:55 +0100
        Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-18 08:31 -0800
          Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 17:38 +0100
  Re: C++ forcing unnecessary changes to C? John Bode <jfbode1029@gmail.com> - 2016-11-18 07:09 -0800
    Re: C++ forcing unnecessary changes to C? Thiago Adams <thiago.adams@gmail.com> - 2016-11-18 07:22 -0800
      Re: C++ forcing unnecessary changes to C? Thiago Adams <thiago.adams@gmail.com> - 2016-11-18 07:31 -0800
        Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 17:04 +0100
  Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-18 16:37 +0100
    Re: C++ forcing unnecessary changes to C? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-18 23:53 +0800
    Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-18 08:00 -0800
      Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 17:34 +0100
      Re: C++ forcing unnecessary changes to C? Keith Thompson <kst-u@mib.org> - 2016-11-18 09:32 -0800
    Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-18 17:09 +0100
      Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-18 18:02 +0100
        Re: C++ forcing unnecessary changes to C? Robert Wessel <robertwessel2@yahoo.com> - 2016-11-21 03:26 -0600
          Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-22 11:11 +0100
            Re: C++ forcing unnecessary changes to C? jameskuyper@verizon.net - 2016-11-22 08:55 -0800
            Re: C++ forcing unnecessary changes to C? Robert Wessel <robertwessel2@yahoo.com> - 2016-11-25 03:25 -0600
              Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-25 10:00 -0800
              Re: C++ forcing unnecessary changes to C? Keith Thompson <kst-u@mib.org> - 2016-11-25 12:30 -0800
                Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-26 00:38 +0100
                Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-26 10:44 -0800
                Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-26 20:44 +0100
                Re: C++ forcing unnecessary changes to C? supercat@casperkitty.com - 2016-11-26 12:38 -0800
                Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-26 21:00 +0100
  Re: C++ forcing unnecessary changes to C? jameskuyper@verizon.net - 2016-11-18 11:04 -0800
    Re: [OT] discipline and obedience "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-19 22:53 +0800
    Re: C & C++ Committee "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-19 22:55 +0800
      Re: C & C++ Committee jameskuyper@verizon.net - 2016-11-19 08:02 -0800
        Re: C & C++ Committee "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-20 00:09 +0800
          Re: C & C++ Committee jameskuyper@verizon.net - 2016-11-19 08:35 -0800
            Re: C & C++ Committee fir <profesor.fir@gmail.com> - 2016-11-19 08:51 -0800
              Re: Do you write C programs? "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-20 01:00 +0800
            Re: C & C++ Committee "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-11-20 00:59 +0800
  Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-22 11:14 +0100
    Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-22 12:05 +0100
      Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-22 14:51 +0100
        Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-22 15:50 +0100
          Re: C++ forcing unnecessary changes to C? BartC <bc@freeuk.com> - 2016-11-22 15:01 +0000
            Re: C++ forcing unnecessary changes to C? Keith Thompson <kst-u@mib.org> - 2016-11-22 08:58 -0800
              Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-22 18:08 +0100
              Re: C++ forcing unnecessary changes to C? BartC <bc@freeuk.com> - 2016-11-22 18:14 +0000
                Re: C++ forcing unnecessary changes to C? Ian Collins <ian-news@hotmail.com> - 2016-11-23 08:33 +1300
                Re: C++ forcing unnecessary changes to C? BartC <bc@freeuk.com> - 2016-11-22 19:42 +0000
                Re: C++ forcing unnecessary changes to C? Ian Collins <ian-news@hotmail.com> - 2016-11-23 08:51 +1300
                Re: C++ forcing unnecessary changes to C? Keith Thompson <kst-u@mib.org> - 2016-11-22 12:13 -0800
                Re: C++ forcing unnecessary changes to C? BartC <bc@freeuk.com> - 2016-11-22 21:35 +0000
                Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-23 00:47 +0100
                Re: C++ forcing unnecessary changes to C? Keith Thompson <kst-u@mib.org> - 2016-11-22 12:09 -0800
                Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-23 00:40 +0100
                Re: C++ forcing unnecessary changes to C? jacobnavia <jacob@jacob.remcomp.fr> - 2016-11-26 01:27 +0100
                Re: C++ forcing unnecessary changes to C? David Brown <david.brown@hesbynett.no> - 2016-11-26 01:48 +0100
              Re: C++ forcing unnecessary changes to C? Nathan Wagner <nw@hydaspes.if.org> - 2016-11-24 18:09 +0000

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