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Article View: comp.lang.c.moderated
Article #2218

Re: "extern" and function declarations

#2218
From: Larry Jones
Date: Fri, 08 Mar 1996 23:10
19 lines
1364 bytes
In article <4hmslm$b3l@solutions.solon.com>, Guillaume Laurent <glaurent@nissart.lagaude.ibm.com> writes:
| I've got a question here : what if the same above declaration is made
| in two (or more) files, compiled seperately then linked together ?
| 
| ie, in file a.c : extern int i = 1;
| and in file b.c : extern int i = 2;
| 
| If I understand correctly what you've said, both of these declarations
| will reserve space, and give i a value. My question is, what decides
| which value will actually be "used", and what happens to the "duplicate"
| space ?

It's undefined.  In some implementations the first one the linker sees
wins, in other implementations the last one the linker sees wins, and in
still other implementations you get an error.
----
Larry Jones, SDRC, 2000 Eastman Dr., Milford, OH  45150-2789  513-576-2070
larry.jones@sdrc.com
Girls are so weird. -- Calvin
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Path: arc1-ca.pugleaf.net!solon.com!not-for-mail
From: larry.jones@sdrc.com (Larry Jones)
Newsgroups: comp.lang.c.moderated
Subject: Re: "extern" and function declarations
Date: 8 Mar 1996 17:10:08 -0600
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