Re: initialization of local static variable

From	jacob navia <jacob@spamsink.net>
Newsgroups	comp.lang.c
Subject	Re: initialization of local static variable
Date	2011-10-08 00:40 +0200
Organization	lccwin
Message-ID	<j6nv5f$tpq$1@speranza.aioe.org> (permalink)
References	(6 earlier) <0.5bf60c50a20af830bcc4.20111007202925BST.87zkhcwqga.fsf@bsb.me.uk> <j6nkfh$3tt$1@speranza.aioe.org> <0.c17dea24b635577dbcc6.20111007211624BST.87hb3kwo9z.fsf@bsb.me.uk> <j6nn1h$al8$1@speranza.aioe.org> <9f9civF6foU1@mid.uni-berlin.de>

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Le 08/10/11 00:25, Jens Thoms Toerring a écrit :
>
> I don't want to argue if this is wrong - you write the compiler
> and thus you define what happens - but, at least to me, it does
> not make things easier to understand or seems to be more cohe-
> rent since I now also have to consider how a static variable is
> initialized in order to figure out how it will behave.
>

Obviously if it is initialized with a constant expression the simple
rule applies as before: it is initialized once by the linker before
the program is loaded

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 see this as very easy to understand but I could be wrong since
I program in C since a long time and can't go back to my beginner
years to verify that it looks coherent to a beginner)

Now, I have a problem with the "once" that Ben pointed out. Should
I generate code that initializes that ONCE?

For instance I could generate code that tests a memory location to see
if the variable is initialized or not and skip the initialization
if it is initialized already.

The whole thing comes down to the existence of an initialization
procedures (like the C++ constructors) that would allow us to
write:

double sqrt2_over_2 = sqrt(2)/2;
int main(void)
{
	printf("%g\n",sqrt2_over_2);
}

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

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