[Bug lto/67548] New: [5/6 Regression] LTO drops weak binding with "ld -r"

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67548

            Bug ID: 67548
           Summary: [5/6 Regression] LTO drops weak binding with "ld -r"
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
  Target Milestone: ---

[hjl@gnu-6 lto]$ cat test.c
extern int x;

void foobar (void) { x--; }
[hjl@gnu-6 lto]$ cat test-weak.c
#include <stdio.h>

int x;

__attribute__((weak))
void foobar (void) { x++; }

int main (void)
{
  foobar ();
  if (x == -1)
    printf ("OK\n");
  return 0;
}
[hjl@gnu-6 lto]$ make
gcc  -flto -O2    -c -o test-weak.o test-weak.c
gcc  -flto -O2  -nostdlib -r -o test-intermediate.o test-weak.o
readelf -sW test-intermediate.o | grep foobar
    10: 0000000000000000     8 FUNC    GLOBAL DEFAULT    1 foobar
gcc  -flto -O2    -c -o test.o test.c
gcc  -flto -O2  test-intermediate.o test.o -o prog
test.o (symbol from plugin): In function `foobar':
(.text+0x0): multiple definition of `foobar'
test-intermediate.o:(.text+0x0): first defined here
/tmp/cciS2u59.ltrans0.ltrans.o: In function `foobar':
<artificial>:(.text+0x0): multiple definition of `foobar'
test-intermediate.o:(.text+0x0): first defined here
collect2: error: ld returned 1 exit status
Makefile:11: recipe for target 'prog' failed
make: *** [prog] Error 1
[hjl@gnu-6 lto]$