c/10697: linker problem with global variable

[bhuang@qubit-star.com]

>Number:         10697
>Category:       c
>Synopsis:       linker problem with global variable
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          pessimizes-code
>Submitter-Id:   net
>Arrival-Date:   Fri May 09 07:06:01 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     falls huang <bhuang@qubit-star.com>
>Release:        gcc version 3.1 20020927 ; gcc version 3.2
>Organization:
>Environment:
redhat 8.0, redhat 9.0, cygwin
>Description:
foo.h:
/*********/
int foo_global;

void f(void);
/*********/

a.c:
/*********/
#include "foo.h"

int main()
{
	foo_global = 5;
	printf("foo_global=%d\n",foo_global);
	f();
	printf("foo_global=%d\n",foo_global);
	return 0;
}
/*********/

b.c:
/*********/
#include "foo.h"

void f(void)
{
	foo_global = -1;
}
/*********/

Makefile:
all:
	gcc -c b.c
	gcc -c a.c
	gcc -o test a.o b.o
	gcc -o test1 -ansic a.c b.c
clean:
	rm -f *.o *.exe test test1 

I type "make" in console and compile the program 
without any warning and error. But I can't compile it
successfully in TurboC3.0 and Borland C.The 
foo_global that defined in foo.h is included in a.c 
and b.c, so I think the linker should report an error
when I link a.o and b.o , but gcc doesn't give any 
warning and error.
>How-To-Repeat:
Create foo.h a.c b.c makefile from my description and type "make" to compile it.
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: