Issue 0020: Is the relaxed Ref/Def linkage model conforming?

This issue has been automatically converted from the original issue lists and some formatting may not have been preserved.

Authors: Bruce Lambert, WG14
Date: 1992-12-10
Reference document: X3J11/91-006
Submitted against: C90
Status: Closed
Converted from: dr.htm, dr_020.html

Is a compiler which allows the Relaxed Ref/Def linkage model to be considered a conforming compiler? That is, can a compiler that compiles the following code with no errors or warnings

filea.c:
 #include stdio.h>
 void foo(void);
 int age;
 int main()
 {
 age = 24;
 printf("my age is %d.\n", age);
 foo();
 printf("my age is %d.\n", age);
 return 0;
 }

 fileb.c:
 #include <stdio.h>
 int age;
 void foo()
 {
 age = 25;
 printf("your age is %d.\n", age);
 }

and which produces the following output

my age is 24
 your age is 25
 my age is 25

be called a standard-compliant compiler?

Comment from WG14 on 1997-09-23:

Response

Yes, a compiler that allows the Relaxed Ref/Def model can be standard conforming. (In this case, the model permits two tentative definitions for age in two translation units to resolve to a single definition at link time.) See subclause 6.7, page 81, lines 23-25. The code is conforming but not strictly conforming. The behavior is undefined.