[Bug c/89347] New: gc-sections doesn't remove unused bss section variables.

[maninder1.s at samsung dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89347

            Bug ID: 89347
           Summary: gc-sections doesn't remove unused bss  section
                    variables.
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: maninder1.s at samsung dot com
  Target Milestone: ---

code snippet:-

int init_bss_unused[10] = {0}; // explicilty initialised with 0
int init_bss_used[10] = {0}; //  explicilty initialised with 0
int uninit_bss_unused[10];
int uninit_bss_used[10];

int main()
{
        uninit_bss_used[5] = 6;
        init_bss_used[5]  = 7;
        return 0;
}

$gcc -fdata-sections -ffunction-sections -Wl,--gc-sections bss.c
$nm -a | grep _bss_
00020714 B init_bss_used      // removed init_bss_unused.
00020764 B uninit_bss_unused  // not removed.