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

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

[sorie at sorie dot net]

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

[Bug c/18935] [3.4 Regression] Error on reference of 'extern' variable in block scope.

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-12-11 01:21 -------
Fixed at least on the mainline: Search converges between 2004-07-31-trunk (#500) and 2004-08-01-
trunk (#501).

But it is a regression from 2.95.3:
: Search converges between 2001-03-11-trunk (#10) and 2001-03-18-trunk (#11).



-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |ice-on-invalid-code
      Known to work|                            |2.95.3 4.0.0
   Last reconfirmed|0000-00-00 00:00:00         |2004-12-11 01:21:44
               date|                            |
            Summary|Error on reference of       |[3.4 Regression] Error on
                   |'extern' variable in block  |reference of 'extern'
                   |scope.                      |variable in block scope.
   Target Milestone|---                         |3.4.4


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