[Bug pch/16599] New: largefile.c:1: fatal error: had to relocate PCH

["danglin at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

Executing on host: /mnt/gnu/gcc-3.3/objdir/gcc/xgcc -B/mnt/gnu/gcc-3.3/objdir/gc
c/ largefile.c   -O0  -I. -S  -o largefile.s    (timeout = 300)
largefile.c:1: fatal error: had to relocate PCH
compilation terminated.
compiler exited with status 1
output is:
largefile.c:1: fatal error: had to relocate PCH
compilation terminated.

FAIL: largefile.c  -O0  (test for excess errors)
Excess errors:
largefile.c:1: fatal error: had to relocate PCH
compilation terminated.

UNTESTED: gcc.dg/pch/largefile.c  -O0  assembly comparison

* Default version of HOST_HOOKS_GT_PCH_USE_ADDRESS when mmap is present.
   Map SIZE bytes of FD+OFFSET at BASE.  Return 1 if we succeeded at
   mapping the data at BASE, -1 if we couldn't.

   This version assumes that the kernel honors the START operand of mmap
   even without MAP_FIXED if START through START+SIZE are not currently
   mapped with something.  */

int
mmap_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)

The START operand of mmap is NOT always honored without MAP_FIXED on the
PA under both hpux and linux.  This is apparently a result of the strict
aliasing requirements of the hardware.

START is will be honored with MAP_FIXED, or mmap will fail.  The current
implementation will generate a hard error if mmap doesn't honor START.
If this failure is caused by a previous mapping in the requested region,
then PCH behavior will be generally unreliable even on systems that honor
START without MAP_FIXED.

Thus, I believe we have to assume that mmap_gt_pch_use_address is called
before other mmap activity that might result in a mapping in the PCH
region.  In that case, we can use or fallback to MAP_FIXED.  The only
other fix that I can see is to eliminate the requirement that the PCH
file be mapped to a fixed address.

-- 
           Summary: largefile.c:1: fatal error: had to relocate PCH
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: pch
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: danglin at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: hppa*-hp-hpux*, hppa*-unknown-linux-gnu
  GCC host triplet: hppa*-hp-hpux*, hppa*-unknown-linux-gnu
GCC target triplet: hppa*-hp-hpux*, hppa*-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16599