* Makefile.in (host_hook_obj): New.

	(OBJS): Add $(host_hook_obj).
	(host_default.o): New rule.
	* config.gcc (host_hook_obj): New, default to host-default.o.
	(powerpc-*-darwin*): Use host-darwin.o.
	(out_host_hook_obj): New.
	* configure: Regenerate.
	* configure.in: Print information about out_host_hook_obj, substitute
	into output files.
	* host-default.c: New file.
	* hosthooks.h: New file.
	* toplev.c (general_init): Call host_hooks.extra_signals.
	* config/rs6000/host-darwin.c: New file.
	* config/rs6000/x-darwin: New file.
	* doc/hostconfig.texi: Add documentation for new host hook.
	Rearrange existing documentation.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@62470 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 137 insertions, 0 deletions

diff --git a/gcc/config/rs6000/host-darwin.c b/gcc/config/rs6000/host-darwin.c
new file mode 100644
index 00000000000..874d691cf3c
--- /dev/null
+++ b/gcc/config/rs6000/host-darwin.c
@@ -0,0 +1,137 @@
+/* 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 "coretypes.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;