[committed] Fix PR pch/14940 on hppa hpux and linux

["John David Anglin" <dave at hiauly1 dot hia dot nrc dot ca>]

The following change fixes the pch failures including largefile.c
under hppa hpux11.11 and hppa-linux.

There doesn't seem to be any way to map to a consistent start address
on hppa-linux using MAP_PRIVATE.  According the the PA-RISC kernel
team, this is due to the strict aliasing requirements of the PA-RISC
hardware.  Thus, I adopted a brute force fix of doing an anonymous
MAP_PRIVATE and copying the data to this mapping.  This still requires
picking a suitable spot.  It's also necessary to pick a good spot
on hppa64-hpux as default kernel placement stills fails largefile.c.
It allocates from top down and the default placement is too high for
some unknown reason in the largefile.c test.

Tested on hppa2.0w-hp-hp-hpux11.11, hppa64-hp-hpux11.11 and
hppa-unknown-linux-gnu.  Committed to trunk.

Dave
-- 
J. David Anglin                                  dave.anglin@nrc-cnrc.gc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6602)

2004-11-29  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>

	PR pch/14940
	* config/pa/pa-host.c, config/pa/x-hpux, config/pa/x-linux: New files.
	* config.host (hppa*-*-hpux*, hppa*-*-linux): Define out_host_hook_obj
	and host_xmake_file using new host configuration files.

--- /dev/null	Sun Nov 28 18:11:57 2004
+++ config/pa/pa-host.c	Sun Nov 28 17:57:00 2004
@@ -0,0 +1,122 @@
+/* PA host-specific hook definitions.
+   Copyright (C) 2004 Free Software Foundation, Inc.
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published
+   by the Free Software Foundation; either version 2, or (at your
+   option) any later version.
+
+   GCC is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING.  If not, write to the
+   Free Software Foundation, 59 Temple Place - Suite 330, Boston,
+   MA 02111-1307, USA.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include <sys/mman.h>
+#include "hosthooks.h"
+#include "hosthooks-def.h"
+
+static void *pa_gt_pch_get_address (size_t, int);
+static int pa_gt_pch_use_address (void *, size_t, int, size_t);
+
+#undef HOST_HOOKS_GT_PCH_GET_ADDRESS
+#define HOST_HOOKS_GT_PCH_GET_ADDRESS pa_gt_pch_get_address
+#undef HOST_HOOKS_GT_PCH_USE_ADDRESS
+#define HOST_HOOKS_GT_PCH_USE_ADDRESS pa_gt_pch_use_address
+
+/* For various ports, try to guess a fixed spot in the vm space
+   that's probably free.  */
+#if defined(__hppa__) && defined(__LP64__)
+# define TRY_EMPTY_VM_SPACE	0x8000000000000000
+#elif defined(__hppa__)
+# define TRY_EMPTY_VM_SPACE	0x60000000
+#else
+# define TRY_EMPTY_VM_SPACE	0
+#endif
+
+/* Determine a location where we might be able to reliably allocate
+   SIZE bytes.  FD is the PCH file, though we should return with the
+   file unmapped.  */
+
+static void *
+pa_gt_pch_get_address (size_t size, int fd)
+{
+  void *addr;
+
+  addr = mmap ((void *)TRY_EMPTY_VM_SPACE, size, PROT_READ | PROT_WRITE,
+	       MAP_PRIVATE, fd, 0);
+
+  /* If we failed the map, that means there's *no* free space.  */
+  if (addr == (void *) MAP_FAILED)
+    return NULL;
+  /* Unmap the area before returning.  */
+  munmap (addr, size);
+
+  return addr;
+}
+
+/* Map SIZE bytes of FD+OFFSET at BASE.  Return 1 if we succeeded at
+   mapping the data at BASE, -1 if we couldn't.
+
+   It's not possibly to reliably mmap a file using MAP_PRIVATE to
+   a specific START address on either hpux or linux.  First we see
+   if mmap with MAP_PRIVATE works.  If it does, we are off to the
+   races.  If it doesn't, we try an anonymous MAP_PRIVATE since the
+   kernel is more likely to honor the BASE address in anonymous maps.
+   We then mmap the file to an arbitrary location and copy the data
+   to the anonymous private map.  This assumes of course that we
+   don't need to change the PCH data after the file is created.
+
+   This approach obviously causes a performance penalty but there is
+   little else we can do given the current PCH implementation.  */
+
+static int
+pa_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
+{
+  void *addr, *faddr;
+
+  /* We're called with size == 0 if we're not planning to load a PCH
+     file at all.  This allows the hook to free any static space that
+     we might have allocated at link time.  */
+  if (size == 0)
+    return -1;
+
+  /* Try to map the file with MAP_PRIVATE.  */
+  addr = mmap (base, size, PROT_READ | PROT_WRITE,
+	       MAP_PRIVATE, fd, offset);
+
+  if (addr == base)
+    return 1;
+
+  if (addr != (void *) MAP_FAILED)
+    munmap (addr, size);
+
+  addr = mmap (base, size, PROT_READ | PROT_WRITE,
+	       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+  if (addr != base)
+    return -1;
+
+  faddr = mmap (NULL, size, PROT_READ, MAP_PRIVATE,
+		fd, offset);
+
+  if (faddr == (void *) MAP_FAILED)
+    return -1;
+
+  memcpy (addr, faddr, size);
+  munmap (faddr, size);
+
+  return 1;
+}
+
+
+const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;
--- /dev/null	Sun Nov 28 18:11:57 2004
+++ config/pa/x-hpux	Sat Nov 27 17:28:59 2004
@@ -0,0 +1,9 @@
+# The ada virtual array implementation requires that indexing be disabled on
+# hosts such as hpux that use a segmented memory architecture.  Both the c
+# and ada files need to be compiled with this option for correct operation.
+X_ADA_CFLAGS=-mdisable-indexing
+
+pa-host.o : $(srcdir)/config/pa/pa-host.c $(CONFIG_H) $(SYSTEM_H) \
+  coretypes.h hosthooks.h hosthooks-def.h $(HOOKS_H)
+	$(CC) -c $(ALL_CFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
+		$(srcdir)/config/pa/pa-host.c
--- /dev/null	Sun Nov 28 18:11:57 2004
+++ config/pa/x-linux	Sat Nov 27 20:57:33 2004
@@ -0,0 +1,4 @@
+pa-host.o : $(srcdir)/config/pa/pa-host.c $(CONFIG_H) $(SYSTEM_H) \
+  coretypes.h hosthooks.h hosthooks-def.h $(HOOKS_H)
+	$(CC) -c $(ALL_CFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
+		$(srcdir)/config/pa/pa-host.c
Index: config.host
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config.host,v
retrieving revision 2.11
diff -u -3 -p -r2.11 config.host
--- config.host	31 Aug 2004 00:28:56 -0000	2.11
+++ config.host	28 Nov 2004 23:54:57 -0000
@@ -113,7 +113,12 @@ case ${host} in
   hppa1.0-*-hpux10* | hppa1.1-*-hpux10* | hppa2*-*-hpux10* | \
   hppa1.0-*-hpux11* | hppa1.1-*-hpux11* | hppa2*-*-hpux11* | \
   hppa*64*-*-hpux11*)
-    host_xmake_file="pa/x-ada"
+    out_host_hook_obj=pa-host.o
+    host_xmake_file=pa/x-hpux
+    ;;
+  hppa*-*-linux*)
+    out_host_hook_obj=pa-host.o
+    host_xmake_file=pa/x-linux
     ;;
   i370-*-opened* | i370-*-mvs* ) # IBM 360/370/390 Architecture
     host_xm_defines='FATAL_EXIT_CODE=12'