host-darwin.c   [plain text]

/* Darwin/powerpc host-specific hook definitions.
   Copyright (C) 2003 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 <signal.h>
#include <sys/ucontext.h>
#include "hosthooks.h"
#include "hosthooks-def.h"
#include "toplev.h"

static void segv_crash_handler PARAMS ((int));
static void segv_handler PARAMS ((int, siginfo_t *, void *));
static void darwin_rs6000_extra_signals PARAMS ((void));

/* No prototype for this, filed as Radar 3150910.  */
extern int sigaltstack(const stack_t *, stack_t *);

#undef HOST_HOOKS_EXTRA_SIGNALS
#define HOST_HOOKS_EXTRA_SIGNALS darwin_rs6000_extra_signals

/* On Darwin/powerpc, a stack fault can be detected as a SIGSEGV that
   faulted on an instruction that's either
   or
   stwux %r1,xxx,%r1
*/

static void
segv_crash_handler (sig)
     int sig ATTRIBUTE_UNUSED;
{
  internal_error ("Segmentation Fault (code)");
}

static void
segv_handler (sig, sip, scp)
     int sig ATTRIBUTE_UNUSED;
     siginfo_t *sip ATTRIBUTE_UNUSED;
     void *scp;
{
  ucontext_t *uc = (ucontext_t *)scp;
  unsigned faulting_insn;

  /* The fault might have happened when trying to run some instruction, in
     which case the next line will segfault _again_.  Handle this case.  */
  signal (SIGSEGV, segv_crash_handler);

  faulting_insn = *(unsigned *)uc->uc_mcontext->ss.srr0;

  /* Note that this only has to work for GCC, so we don't have to deal
     with all the possible cases (GCC has no AltiVec code, for
     instance).  It's complicated because Darwin allows stores to
     below the stack pointer, and the prologue code takes advantage of
     this.  */

  if ((faulting_insn & 0xFFFF8000) == 0x94218000  /* stwu %r1, -xxx(%r1) */
      || (faulting_insn & 0xFFFF03FF) == 0x7C21016E /* stwux %r1, xxx, %r1 */
      || (faulting_insn & 0xFC1F8000) == 0x90018000 /* stw xxx, -yyy(%r1) */
      || (faulting_insn & 0xFC1F8000) == 0xD8018000 /* stfd xxx, -yyy(%r1) */
      || (faulting_insn & 0xFC1F8000) == 0xBC018000 /* stmw xxx, -yyy(%r1) */)
    {
      char *shell_name;
      
      fnotice (stderr, "Out of stack space.\n");
      shell_name = getenv ("SHELL");
      if (shell_name != NULL)
	shell_name = strrchr (shell_name, '/');
      if (shell_name != NULL)
	{
	  static const char * shell_commands[][2] = {
	    { "sh", "ulimit -S -s unlimited" },
	    { "bash", "ulimit -S -s unlimited" },
	    { "tcsh", "limit stacksize unlimited" },
	    { "csh", "limit stacksize unlimited" },
	    /* zsh doesn't have "unlimited", this will work under the
	       default configuration.  */
	    { "zsh", "limit stacksize 32m" }
	  };
	  size_t i;
	  
	  for (i = 0; i < ARRAY_SIZE (shell_commands); i++)
	    if (strcmp (shell_commands[i][0], shell_name + 1) == 0)
	      {
		fnotice (stderr, 
			 "Try running `%s' in the shell to raise its limit.\n",
			 shell_commands[i][1]);
	      }
	}
      
      exit (FATAL_EXIT_CODE);
    }

  fprintf (stderr, "[address=%08lx pc=%08x]\n", 
	   uc->uc_mcontext->es.dar, uc->uc_mcontext->ss.srr0);
  internal_error ("Segmentation Fault");
  exit (FATAL_EXIT_CODE);
}

static void
darwin_rs6000_extra_signals ()
{
  struct sigaction sact;
  stack_t sigstk;

  sigstk.ss_sp = xmalloc (SIGSTKSZ);
  sigstk.ss_size = SIGSTKSZ;
  sigstk.ss_flags = 0;
  if (sigaltstack (&sigstk, NULL) < 0)
    fatal_io_error ("While setting up signal stack");

  sigemptyset(&sact.sa_mask);
  sact.sa_flags = SA_ONSTACK | SA_SIGINFO;
  sact.sa_sigaction = segv_handler;
  if (sigaction (SIGSEGV, &sact, 0) < 0) 
    fatal_io_error ("While setting up signal handler");
}

const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;