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Groups > comp.lang.c > #109624

Re: error: initializer element is not constant|

Newsgroups comp.lang.c
Date 2017-05-09 12:50 -0700
References (9 earlier) <zKmQA.84548$jo6.54626@fx33.iad> <oestp7$gkd$1@gioia.aioe.org> <3dv3hc1ueu2en2hl1oprs3ui6j6bdoqmf1@4ax.com> <oet0bm$l6s$2@gioia.aioe.org> <lny3u597uc.fsf@kst-u.example.com>
Message-ID <a75fdbe7-307a-43cb-b731-e159605af894@googlegroups.com> (permalink)
Subject Re: error: initializer element is not constant|
From supercat@casperkitty.com

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On Tuesday, May 9, 2017 at 1:57:22 PM UTC-5, Keith Thompson wrote:
> On the other hand, given:
> 
>     char foo[] = "hello";
>     char *bar = foo;
> 
> the expression `foo` in the initializer yields the address of a
> static object, not the (current) value of that object.  The compiler
> has to be able to generate code that refers to the address of a
> static object anyway, so there's no extra burden in requiring it
> to treat such an address as a compile-time constant expression.

Actually, in some cases the latter may be a significant burden, but it is
one that the authors of the C Standard thought was worthwhile to impose.
Most notably, there are some platforms where static variables are accessed
using a displacement from an address register.  Such a design makes it
practical for a system without a memory-management unit (e.g. the classic
Macintosh) to have multiple applications in memory simultaneously but means
that after a program is loaded into memory as a blob, the startup code will
need to patch all static objects that are initialized to hold addresses of
functions or other static objects.

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Thread

error: initializer element is not constant| jak <please@nospam.tnx> - 2017-05-08 09:55 +0200
  Re: error: initializer element is not constant| jak <please@nospam.tnx> - 2017-05-08 10:05 +0200
  Re: error: initializer element is not constant| Noob <root@127.0.0.1> - 2017-05-08 10:38 +0200
    Re: error: initializer element is not constant| jak <please@nospam.tnx> - 2017-05-08 11:55 +0200
      Re: error: initializer element is not constant| bartc <bc@freeuk.com> - 2017-05-08 11:01 +0100
        Re: error: initializer element is not constant| jak <please@nospam.tnx> - 2017-05-08 12:18 +0200
          Re: error: initializer element is not constant| bartc <bc@freeuk.com> - 2017-05-08 12:02 +0100
            Re: error: initializer element is not constant| Keith Thompson <kst-u@mib.org> - 2017-05-08 09:00 -0700
              Re: error: initializer element is not constant| bartc <bc@freeuk.com> - 2017-05-08 17:50 +0100
                Re: error: initializer element is not constant| Keith Thompson <kst-u@mib.org> - 2017-05-08 11:37 -0700
                Re: error: initializer element is not constant| bartc <bc@freeuk.com> - 2017-05-08 19:49 +0100
                Re: error: initializer element is not constant| Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-05-08 20:13 +0100
                Re: error: initializer element is not constant| Keith Thompson <kst-u@mib.org> - 2017-05-08 12:44 -0700
                Re: error: initializer element is not constant| scott@slp53.sl.home (Scott Lurndal) - 2017-05-08 20:24 +0000
            Re: error: initializer element is not constant| jak <please@nospam.tnx> - 2017-05-09 09:54 +0200
              Re: error: initializer element is not constant| jak <please@nospam.tnx> - 2017-05-09 10:15 +0200
              Re: error: initializer element is not constant| GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-05-09 12:12 +0200
              Re: error: initializer element is not constant| bartc <bc@freeuk.com> - 2017-05-09 11:47 +0100
                Re: error: initializer element is not constant| jak <please@nospam.tnx> - 2017-05-09 19:06 +0200
                Re: error: initializer element is not constant| scott@slp53.sl.home (Scott Lurndal) - 2017-05-09 17:10 +0000
                Re: error: initializer element is not constant| jak <please@nospam.tnx> - 2017-05-09 19:20 +0200
                Re: error: initializer element is not constant| Barry Schwarz <schwarzb@dqel.com> - 2017-05-09 10:35 -0700
                Re: error: initializer element is not constant| jak <please@nospam.tnx> - 2017-05-09 20:04 +0200
                Re: error: initializer element is not constant| Keith Thompson <kst-u@mib.org> - 2017-05-09 11:57 -0700
                Re: error: initializer element is not constant| supercat@casperkitty.com - 2017-05-09 12:50 -0700
                Re: error: initializer element is not constant| Keith Thompson <kst-u@mib.org> - 2017-05-09 12:54 -0700
                Re: error: initializer element is not constant| bartc <bc@freeuk.com> - 2017-05-09 20:15 +0100
                Re: error: initializer element is not constant| "James R. Kuyper" <jameskuyper@verizon.net> - 2017-05-09 14:13 -0400
                Re: error: initializer element is not constant| Keith Thompson <kst-u@mib.org> - 2017-05-09 11:41 -0700
              Re: error: initializer element is not constant| Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-05-09 12:16 +0100
              Re: error: initializer element is not constant| Keith Thompson <kst-u@mib.org> - 2017-05-09 08:11 -0700
          Re: error: initializer element is not constant| Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-05-08 12:12 +0100
            Re: error: initializer element is not constant| bartc <bc@freeuk.com> - 2017-05-08 13:45 +0100
              Re: error: initializer element is not constant| Keith Thompson <kst-u@mib.org> - 2017-05-08 09:04 -0700
              Re: error: initializer element is not constant| Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-05-08 19:53 +0100
                Re: error: initializer element is not constant| bartc <bc@freeuk.com> - 2017-05-08 20:44 +0100
                Re: error: initializer element is not constant| Noob <root@127.0.0.1> - 2017-05-09 09:27 +0200
              Re: error: initializer element is not constant| Tim Rentsch <txr@alumni.caltech.edu> - 2017-05-09 07:10 -0700
            Re: error: initializer element is not constant| Keith Thompson <kst-u@mib.org> - 2017-05-08 09:30 -0700
  Re: error: initializer element is not constant| John Bode <jfbode1029@gmail.com> - 2017-05-08 08:05 -0700

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