[Bug c/18935] New: Error on reference of 'extern' variable in block scope.

["sorie at sorie dot net" <gcc-bugzilla at gcc dot gnu dot org>]

This problem occurs in both mode c89 and c99.

I will try to describe it with a simple example.

----- code.c ------------------------------

#include <stdio.h>

int main(void)
{
        extern int a;

        printf("a: %d\n", a);

        int a = 20; /* internal compiler error */

        return 0;
}

-----------------------------------------

If you compile this code, you'll get follwing error message.

$ gcc -Wall -std=c89 code.c
code.c: In function `main':
code.c:7: internal compiler error: in make_decl_rtl, at varasm.c:752

Inside a block scope, the codes are executed sequently.
So I think, when there is a variable declaration with 'extern', that the
compiler should either let occur an error of double variable-declaration or show
warning only and just give the local variable priority.

Thank you for reading.

-- 
           Summary: Error on reference of 'extern' variable in block scope.
           Product: gcc
           Version: 3.4.3
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: sorie at sorie dot net
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18935