=========== Begin complete code ===========
#include <stdio.h>
static int y = -1234;
int main(void)
{
extern int y;
printf("%d\n", y);
return 0;
}
=========== End complete code ===========
command line: gcc -W -Wall test.c
Output:
test.c:3: warning: 'y' defined but not used
As you can see "y" is defined (in line 3), then declared in line 7
and used in line 8. The program also executes correctly.
The use of an "extern" storage class specifier is a bit unusual
but perfectly legal (See ISO/IEC 9899:1999 chapter 6.2.2, paragraph 4).
If anything a warning about this slightly obscure construct might be in OK,
but not about an unused variable.
I would have liked to verify with a newer GCC version but haven't
got any available here, sorry.
--
Summary: Incorrect warning "defined but not used"
Product: gcc
Version: 3.4.4
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: ahelm at gmx dot net
GCC host triplet: i686-pc-cygwin
GCC target triplet: i686-pc-cygwin
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40661
