[Bug driver/61868] New: -frandom-seed always results in random_seed of 0

[Bug driver/61868] New: -frandom-seed always results in random_seed of 0

[bmei at broadcom dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61868

            Bug ID: 61868
           Summary: -frandom-seed always results in random_seed of 0
           Product: gcc
           Version: 4.10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: driver
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bmei at broadcom dot com

Compile any simple file with -frandom-seed and -flto option. 

#include <stdio.h>
extern int foo (int);
int bar (int a)
{
  return a * 5;
}

int main ()
{
  printf("%d\n", foo (100));
  return 0;
}

 ~/scratch/install-x86/bin/gcc tst2.c -flto -c -frandom-seed=12345
objdump -D tst2.o|less

You can see all the lto section has suffix of 0 instead of the random_seed
specified.
<.gnu.lto_.inline.0>

This is because of the following code in toplev.c. If flag_random_seed is true,
then init_random_seed is not called in get_random_seed despite the piece of
code trying to generate random_seed if flag_random_seed is true.

static void
init_random_seed (void)
{
  if (flag_random_seed)
    {
      char *endp;

      /* When the driver passed in a hex number don't crc it again */
      random_seed = strtoul (flag_random_seed, &endp, 0);
      if (!(endp > flag_random_seed && *endp == 0))
        random_seed = crc32_string (0, flag_random_seed);
    }
  else if (!random_seed)
    random_seed = local_tick ^ getpid ();  /* Old racey fallback method */
}

/* Obtain the random_seed.  Unless NOINIT, initialize it if
   it's not provided in the command line.  */

HOST_WIDE_INT
get_random_seed (bool noinit)
{
  if (!flag_random_seed && !noinit)
    init_random_seed ();
  return random_seed;
}

[Bug lto/61868] -frandom-seed always results in random_seed of 0

[bmei at broadcom dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61868

Bingfeng Mei <bmei at broadcom dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|driver                      |lto

--- Comment #1 from Bingfeng Mei <bmei at broadcom dot com> ---
Change the component to lto as gcc should generate lto section name with
specified random seed.

[Bug lto/61868] -frandom-seed always results in random_seed of 0

[bmei at broadcom dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61868

Bingfeng Mei <bmei at broadcom dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED

--- Comment #3 from Bingfeng Mei <bmei at broadcom dot com> ---
Fixed in r213321