Re: initialization of local static variable

From	"BartC" <bc@freeuk.com>
Newsgroups	comp.lang.c
Subject	Re: initialization of local static variable
Date	2011-10-08 01:26 +0100
Organization	A noiseless patient Spider
Message-ID	<j6o5da$o89$1@dont-email.me> (permalink)
References	(7 earlier) <0.c17dea24b635577dbcc6.20111007211624BST.87hb3kwo9z.fsf@bsb.me.uk> <j6nn1h$al8$1@speranza.aioe.org> <9f9civF6foU1@mid.uni-berlin.de> <j6nv5f$tpq$1@speranza.aioe.org> <9f9i99Ff4oU1@mid.uni-berlin.de>

Show all headers | View raw

"Jens Thoms Toerring" <jt@toerring.de> wrote in message 
news:9f9i99Ff4oU1@mid.uni-berlin.de...
> jacob navia <jacob@spamsink.net> wrote:

>> If the expression is not constant it will be initialized when the
>> program executes the initialization statement (it can't be otherwise
>> since it is NOT a constant expression)
>
> I could be completely wrong here since I don't have your compiler
> installed and thus have to rely on BartC's descriptions. But if
> he's correct and I understanding his descriptions correctly a static
> variable with a constant expression initializer is initialized only
> once, while one with a non-constant expression initializer is set
> again each time the function is called. If this is true then I
> would think things might become confusing: what actually is a "con-
> stant expression" can be a bit difficult to see

It really requires two different symbols:

 '='      to mean dynamic assignment
 '=='   (perhaps) to mean one-time initialisation

The trouble is the current usage in C uses '=' for both meanings. That might 
be OK if 'static' only ever means a one-time initialisation. But trying to 
extend the way initialisation for statics is done causes some confusion when 
just the one symbol is used for both ways.

And having a separate rule for 'constant' and 'non-constant' is not really 
workable either for the reasons you've stated. And suppose you *did* want to 
initialise multiple times with a constant?

-- 
Bartc

Thread

initialization of local static variable "V.Subramanian, India" <subramanian100in@yahoo.com> - 2011-10-06 23:33 -0700
  Re: initialization of local static variable pete <pfiland@mindspring.com> - 2011-10-07 02:51 -0400
  Re: initialization of local static variable "BartC" <bc@freeuk.com> - 2011-10-07 10:44 +0100
  Re: initialization of local static variable China Blue Corn Chips <chine.bleu@yahoo.com> - 2011-10-07 03:03 -0700
    Re: initialization of local static variable "BartC" <bc@freeuk.com> - 2011-10-07 11:33 +0100
      Re: initialization of local static variable jt@toerring.de (Jens Thoms Toerring) - 2011-10-07 11:11 +0000
        Re: initialization of local static variable "BartC" <bc@freeuk.com> - 2011-10-07 12:51 +0100
          Re: initialization of local static variable jt@toerring.de (Jens Thoms Toerring) - 2011-10-07 15:56 +0000
            Re: initialization of local static variable Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-07 20:29 +0100
              Re: initialization of local static variable jacob navia <jacob@spamsink.net> - 2011-10-07 21:38 +0200
                Re: initialization of local static variable Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-07 21:16 +0100
                Re: initialization of local static variable jacob navia <jacob@spamsink.net> - 2011-10-07 22:22 +0200
                Re: initialization of local static variable jt@toerring.de (Jens Thoms Toerring) - 2011-10-07 22:25 +0000
                Re: initialization of local static variable jacob navia <jacob@spamsink.net> - 2011-10-08 00:40 +0200
                Re: initialization of local static variable Ian Collins <ian-news@hotmail.com> - 2011-10-08 11:56 +1300
                Re: initialization of local static variable jacob navia <jacob@spamsink.net> - 2011-10-08 01:53 +0200
                Re: initialization of local static variable Jens Gustedt <jens.gustedt@loria.fr> - 2011-10-09 23:04 +0200
                Re: initialization of local static variable Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-10-10 11:54 -0500
                Re: initialization of local static variable Ike Naar <ike@sverige.freeshell.org> - 2011-10-10 17:41 +0000
                Re: initialization of local static variable Andrew Haley <andrew29@littlepinkcloud.invalid> - 2011-10-10 17:35 -0500
                Re: initialization of local static variable jt@toerring.de (Jens Thoms Toerring) - 2011-10-08 00:02 +0000
                Re: initialization of local static variable "BartC" <bc@freeuk.com> - 2011-10-08 01:26 +0100
                Re: initialization of local static variable "Philip Lantz" <prl@canterey.us> - 2011-10-08 03:01 -0700
                Re: initialization of local static variable "BartC" <bc@freeuk.com> - 2011-10-07 21:42 +0100
                Re: initialization of local static variable China Blue Corn Chips <chine.bleu@yahoo.com> - 2011-10-07 16:25 -0700
                Re: initialization of local static variable jacob navia <jacob@spamsink.net> - 2011-10-08 01:51 +0200
                Re: initialization of local static variable China Blue Corn Chips <chine.bleu@yahoo.com> - 2011-10-07 18:21 -0700
                Re: initialization of local static variable Nobody <nobody@nowhere.com> - 2011-10-08 15:36 +0100
                Re: initialization of local static variable Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-08 22:06 +0100
                Re: initialization of local static variable Nobody <nobody@nowhere.com> - 2011-10-09 05:35 +0100
                Re: initialization of local static variable Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-10-09 09:25 +0100
                Re: initialization of local static variable "io_x" <a@b.c.invalid> - 2011-10-09 11:00 +0200
                Re: initialization of local static variable Barry Schwarz <schwarzb@dqel.com> - 2011-10-09 10:56 -0700
                Re: initialization of local static variable James Kuyper <jameskuyper@verizon.net> - 2011-10-09 14:30 -0400
                Re: initialization of local static variable Barry Schwarz <schwarzb@dqel.com> - 2011-10-09 21:43 -0700
                Re: initialization of local static variable "io_x" <a@b.c.invalid> - 2011-10-10 19:08 +0200
                Re: initialization of local static variable Geoff <geoff@invalid.invalid> - 2011-10-10 16:16 -0700
                Re: initialization of local static variable Ike Naar <ike@iceland.freeshell.org> - 2011-10-10 23:22 +0000
                Re: initialization of local static variable James Kuyper <jameskuyper@verizon.net> - 2011-10-10 20:40 -0400
                Re: initialization of local static variable Barry Schwarz <schwarzb@dqel.com> - 2011-10-10 20:54 -0700
                Re: initialization of local static variable "io_x" <a@b.c.invalid> - 2011-10-11 18:45 +0200
                Re: initialization of local static variable "io_x" <a@b.c.invalid> - 2011-10-11 18:51 +0200
                Re: initialization of local static variable Barry Schwarz <schwarzb@dqel.com> - 2011-10-11 18:52 -0700
                Re: initialization of local static variable "io_x" <a@b.c.invalid> - 2011-10-12 08:49 +0200
                Re: initialization of local static variable "io_x" <a@b.c.invalid> - 2011-10-11 19:48 +0200
                Re: initialization of local static variable Barry Schwarz <schwarzb@dqel.com> - 2011-10-11 21:25 -0700
                Re: initialization of local static variable "io_x" <a@b.c.invalid> - 2011-10-12 08:48 +0200
                Re: initialization of local static variable "io_x" <a@b.c.invalid> - 2011-10-12 08:54 +0200
                Re: initialization of local static variable pete <pfiland@mindspring.com> - 2011-10-12 20:55 -0400
                Re: initialization of local static variable Barry Schwarz <schwarzb@dqel.com> - 2011-10-11 18:52 -0700
                Re: initialization of local static variable "io_x" <a@b.c.invalid> - 2011-10-11 19:55 +0200
                Re: initialization of local static variable Keith Thompson <kst-u@mib.org> - 2011-10-11 11:24 -0700
                Re: initialization of local static variable Keith Thompson <kst-u@mib.org> - 2011-10-11 12:47 -0700
                Re: initialization of local static variable "io_x" <a@b.c.invalid> - 2011-10-12 08:49 +0200
            Re: initialization of local static variable Tim Rentsch <txr@alumni.caltech.edu> - 2012-01-24 16:09 -0800
          Re: initialization of local static variable China Blue Corn Chips <chine.bleu@yahoo.com> - 2011-10-07 16:06 -0700
            Re: initialization of local static variable Seebs <usenet-nospam@seebs.net> - 2011-10-12 22:25 +0000
              Re: initialization of local static variable "christian.bau" <christian.bau@cbau.wanadoo.co.uk> - 2011-10-13 07:09 -0700
                Re: initialization of local static variable Seebs <usenet-nospam@seebs.net> - 2011-10-17 17:21 +0000
              Re: initialization of local static variable Joe Wright <joewwright@comcast.net> - 2011-10-14 14:27 -0400
          Re: initialization of local static variable Richard Damon <news.x.richarddamon@xoxy.net> - 2011-10-08 00:03 -0400
            Re: initialization of local static variable China Blue Corn Chips <chine.bleu@yahoo.com> - 2011-10-08 01:27 -0700
          Re: initialization of local static variable Richard Damon <news.x.richarddamon@xoxy.net> - 2011-10-08 00:08 -0400

csiph-web