Makefile.in (host_hook_obj): New.

	* 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.

From-SVN: r62470

gcc/ChangeLog

+2003-02-05  Geoffrey Keating  <geoffk@apple.com>
+
+	* 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.
+
 2003-02-05  Roger Sayle  <roger@eyesopen.com>
 
 	* dwarf2out.c (mem_loc_descriptor): Replace ASM_SIMPLIFY_DWARF_ADDR

gcc/Makefile.in

@@ -315,6 +315,7 @@ target_cpu_default=@target_cpu_default@
 GCC_THREAD_FILE=@thread_file@
 OBJC_BOEHM_GC=@objc_boehm_gc@
 GTHREAD_FLAGS=@gthread_flags@
+host_hook_obj=@out_host_hook_obj@
 # Be prepared for gcc2 merges.
 gcc_version=@gcc_version@
 gcc_version_trigger=@gcc_version_trigger@
@@ -784,7 +785,8 @@ OBJS = alias.o bb-reorder.o bitmap.o builtins.o caller-save.o calls.o	   \
  sibcall.o simplify-rtx.o ssa.o ssa-ccp.o ssa-dce.o stmt.o		   \
  stor-layout.o stringpool.o timevar.o toplev.o tracer.o tree.o tree-dump.o \
  tree-inline.o unroll.o varasm.o varray.o version.o vmsdbgout.o xcoffout.o \
- alloc-pool.o et-forest.o $(GGC) $(out_object_file) $(EXTRA_OBJS)
+ alloc-pool.o et-forest.o						   \
+ $(GGC) $(out_object_file) $(EXTRA_OBJS) $(host_hook_obj)
 
 BACKEND = main.o libbackend.a
 
@@ -1428,12 +1430,15 @@ toplev.o : toplev.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) $(RTL_
    dwarf2out.h sdbout.h dbxout.h $(EXPR_H) hard-reg-set.h $(BASIC_BLOCK_H) \
    graph.h $(LOOP_H) except.h $(REGS_H) $(TIMEVAR_H) $(lang_options_files) \
    ssa.h $(PARAMS_H) $(TM_P_H) reload.h dwarf2asm.h $(TARGET_H) \
-   langhooks.h insn-flags.h options.h cfglayout.h real.h cfgloop.h
+   langhooks.h insn-flags.h options.h cfglayout.h real.h cfgloop.h hosthooks.h
 	$(CC) $(ALL_CFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
 	  -DTARGET_NAME=\"$(target_alias)\" \
 	  -c $(srcdir)/toplev.c $(OUTPUT_OPTION)
 main.o : main.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) toplev.h
 
+host-default.o : host-default.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
+	hosthooks.h hosthooks-def.h
+
 rtl-error.o: rtl-error.c $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) $(INSN_ATTR_H) \
    insn-config.h input.h toplev.h intl.h diagnostic.h $(CONFIG_H)
 

gcc/config.gcc

@@ -99,6 +99,8 @@
 #  host_extra_gcc_objs	List of extra host-dependent objects that should
 #			be linked into the gcc driver.
 #
+#  out_host_hook_obj	An object file that provides the host hooks.
+#
 #  c_target_objs	List of extra target-dependent objects that be
 #			linked into the C compiler only.
 #
@@ -169,6 +171,8 @@
 #			the compiler proper when this system is a host,
 #			for host_extra_objs.
 #
+#  host_hook_obj	An object file that provides the host hooks.
+#
 #  install_headers_dir	Makefile-target for how the header file directory
 #			is installed, when this system is a build system,
 #			for build_install_headers_dir.
@@ -194,6 +198,7 @@ extra_host_objs=
 extra_gcc_objs=
 c_target_objs=
 cxx_target_objs=
+host_hook_obj=host-default.o
 tm_defines=
 xm_defines=
 # Set this to force installation and use of collect2.
@@ -1980,6 +1985,9 @@ powerpc-*-darwin*)
 	extra_headers=altivec.h
 	# override ppc default
 	need_64bit_hwint=
+	# powerpc-darwin host support.
+	host_hook_obj=host-darwin.o
+	xmake_file=rs6000/x-darwin
 	;;
 powerpc*-*-freebsd*)
 	tm_file="${tm_file} dbxelf.h elfos.h ${fbsd_tm_file} rs6000/sysv4.h rs6000/freebsd.h"
@@ -2956,6 +2964,7 @@ else
 		host_extra_gcc_objs=$extra_gcc_objs
 		host_extra_objs=$extra_host_objs
 		host_exeext=$exeext
+		out_host_hook_obj=$host_hook_obj
 		pass2done=yes
 	fi
 fi

gcc/config/rs6000/host-darwin.c

+/* 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;

gcc/config/rs6000/x-darwin

+host-darwin.o : $(srcdir)/config/rs6000/host-darwin.c $(CONFIG_H) $(SYSTEM_H) \
+  coretypes.h hosthooks.h hosthooks-def.h toplev.h
+	$(CC) -c $(ALL_CFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
+		$(srcdir)/config/rs6000/host-darwin.c

gcc/configure.in

@@ -956,6 +956,7 @@ else
 		echo "	$srcdir/config/$f"
 	done
 fi
+echo "Using ${out_host_hook_obj} for host machine hooks."
 
 if test "$host_xm_file" != "$build_xm_file"; then
 	count=a
@@ -2858,6 +2859,7 @@ AC_SUBST(host_extra_gcc_objs)
 AC_SUBST(host_xm_file_list)
 AC_SUBST(host_xm_file)
 AC_SUBST(host_xm_defines)
+AC_SUBST(out_host_hook_obj)
 AC_SUBST(install)
 AC_SUBST(lang_options_files)
 AC_SUBST(lang_specs_files)

gcc/doc/hostconfig.texi

-@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-@c 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+@c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+@c 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
 @c This is part of the GCC manual.
-@c For copying conditions, see the file gcc.texi.
+@c For copying conditions, see the file gccint.texi.
 
 @node Host Config
-@chapter Host Configuration Headers
+@chapter Host Configuration
+@cindex host configuration
+
+Most details about the machine and system on which the compiler is
+actually running are detected by the @command{configure} script.  Some
+things are impossible for @command{configure} to detect; these are
+described in two ways, either by macros defined in a file named
+@file{xm-@var{machine}.h} or by hook functions in the file specified
+by the @var{out_host_hook_obj} variable in @file{config.gcc}.  (The
+intention is that very few hosts will need a header file but nearly
+every fully supported host will need to override some hooks.)
+
+If you need to define only a few macros, and they have simple
+definitions, consider using the @code{xm_defines} variable in your
+@file{config.gcc} entry instead of creating a host configuration
+header.  @xref{System Config}.
+
+@menu
+* Host Common::		Things every host probably needs implemented.
+* Filesystem::          Your host can't have the letter `a' in filenames?
+* Host Misc::         	Rare configuration options for hosts.
+@end menu
+
+@node Host Common
+@section Host Common
+@cindex host hooks
+@cindex host functions
+
+Some things are just not portable, even between similar operating systems,
+and are too difficult for autoconf to detect.  They get implemented using
+hook functions in the file specified by the @var{host_hook_obj}
+variable in @file{config.gcc}.
+
+@deftypefn {Host Hook} void HOST_HOOKS_EXTRA_SIGNALS (void)
+This host hook is used to set up handling for extra signals.  The most
+common thing to do in this hook is to detect stack overflow.
+@end deftypefn
+
+@node Filesystem
+@section Host Filesystem
 @cindex configuration file
 @cindex @file{xm-@var{machine}.h}
 
-Host configuration headers contain macro definitions that describe the
-machine and system on which the compiler is running.  They are usually
-unnecessary.  Most of the things GCC needs to know about the host
-system can be deduced by the @command{configure} script.
-
-If your host does need a special configuration header, it should be
-named @file{xm-@var{machine}.h}, where @var{machine} is a short mnemonic
-for the machine.  Here are some macros which this header can define.
+GCC supports some filesystems that are very different to standard Unix
+filesystems.  These macros, defined in @file{xm-@var{machine}.h},
+let you choose.
 
 @ftable @code
 @item VMS
 Define this macro if the host system is VMS@.
 
-@item FATAL_EXIT_CODE
-A C expression for the status code to be returned when the compiler
-exits after serious errors.  The default is the system-provided macro
-@samp{EXIT_FAILURE}, or @samp{1} if the system doesn't define that
-macro.  Define this macro only if these defaults are incorrect.
-
-@item SUCCESS_EXIT_CODE
-A C expression for the status code to be returned when the compiler
-exits without serious errors.  (Warnings are not serious errors.)  The
-default is the system-provided macro @samp{EXIT_SUCCESS}, or @samp{0} if
-the system doesn't define that macro.  Define this macro only if these
-defaults are incorrect.
-
-@item USE_C_ALLOCA
-Define this macro if GCC should use the C implementation of @code{alloca}
-provided by @file{libiberty.a}.  This only affects how some parts of the
-compiler itself allocate memory.  It does not change code generation.
-
-When GCC is built with a compiler other than itself, the C @code{alloca}
-is always used.  This is because most other implementations have serious
-bugs.  You should define this macro only on a system where no
-stack-based @code{alloca} can possibly work.  For instance, if a system
-has a small limit on the size of the stack, GCC's builtin @code{alloca}
-will not work reliably.
-
 @item HAVE_DOS_BASED_FILE_SYSTEM
 Define this macro if the host file system obeys the semantics defined by
 MS-DOS instead of Unix.  DOS file systems are case insensitive, file
@@ -86,14 +95,6 @@ you do not define this macro, GCC will use @samp{/dev/null} as the bit
 bucket.  If the host does not support a bit bucket, define this macro to
 an invalid filename.
 
-@item COLLECT2_HOST_INITIALIZATION
-If defined, a C statement (sans semicolon) that performs host-dependent
-initialization when @code{collect2} is being initialized.
-
-@item GCC_DRIVER_HOST_INITIALIZATION
-If defined, a C statement (sans semicolon) that performs host-dependent
-initialization when a compilation driver is being initialized.
-
 @item UPDATE_PATH_HOST_CANONICALIZE (@var{path})
 If defined, a C statement (sans semicolon) that performs host-dependent
 canonicalization when a path used in a compilation driver or
@@ -112,6 +113,46 @@ unique to each dump file kind, e.g. @samp{rtl}.
 
 If you do not define this macro, GCC will use @samp{.%02d.}.  You should
 define this macro if using the default will create an invalid file name.
+@end ftable
+
+@node Host Misc
+@section Host Misc
+@cindex configuration file
+@cindex @file{xm-@var{machine}.h}
+
+@ftable @code
+@item FATAL_EXIT_CODE
+A C expression for the status code to be returned when the compiler
+exits after serious errors.  The default is the system-provided macro
+@samp{EXIT_FAILURE}, or @samp{1} if the system doesn't define that
+macro.  Define this macro only if these defaults are incorrect.
+
+@item SUCCESS_EXIT_CODE
+A C expression for the status code to be returned when the compiler
+exits without serious errors.  (Warnings are not serious errors.)  The
+default is the system-provided macro @samp{EXIT_SUCCESS}, or @samp{0} if
+the system doesn't define that macro.  Define this macro only if these
+defaults are incorrect.
+
+@item USE_C_ALLOCA
+Define this macro if GCC should use the C implementation of @code{alloca}
+provided by @file{libiberty.a}.  This only affects how some parts of the
+compiler itself allocate memory.  It does not change code generation.
+
+When GCC is built with a compiler other than itself, the C @code{alloca}
+is always used.  This is because most other implementations have serious
+bugs.  You should define this macro only on a system where no
+stack-based @code{alloca} can possibly work.  For instance, if a system
+has a small limit on the size of the stack, GCC's builtin @code{alloca}
+will not work reliably.
+
+@item COLLECT2_HOST_INITIALIZATION
+If defined, a C statement (sans semicolon) that performs host-dependent
+initialization when @code{collect2} is being initialized.
+
+@item GCC_DRIVER_HOST_INITIALIZATION
+If defined, a C statement (sans semicolon) that performs host-dependent
+initialization when a compilation driver is being initialized.
 
 @item SMALL_ARG_MAX
 Define this macro if the host system has a small limit on the total
@@ -123,8 +164,3 @@ In addition, if @command{configure} generates an incorrect definition of
 any of the macros in @file{auto-host.h}, you can override that
 definition in a host configuration header.  If you need to do this,
 first see if it is possible to fix @command{configure}.
-
-If you need to define only a few of these macros, and they have simple
-definitions, consider using the @code{xm_defines} variable in your
-@file{config.gcc} entry instead of creating a host configuration header.
-@xref{System Config}.

gcc/host-default.c

+/* Default 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 "hosthooks.h"
+#include "hosthooks-def.h"
+
+const struct host_hooks host_hooks = HOST_HOOKS_INITIALIZER;

gcc/hosthooks-def.h

+/* Default macros to initialize the lang_hooks data structure.
+   Copyright 2003 Free Software Foundation, Inc.
+
+This file is part of GNU CC.
+
+GNU CC 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.
+
+GNU CC 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 GNU CC; see the file COPYING.  If not, write to
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+#ifndef GCC_HOST_HOOKS_DEF_H
+#define GCC_HOST_HOOKS_DEF_H
+
+#include "hooks.h"
+
+#define HOST_HOOKS_EXTRA_SIGNALS hook_void_void
+
+/* The structure is defined in hosthooks.h.  */
+#define HOST_HOOKS_INITIALIZER {		\
+  HOST_HOOKS_EXTRA_SIGNALS			\
+}
+
+#endif /* GCC_HOST_HOOKS_DEF_H */

gcc/hosthooks.h

+/* The host_hooks data structure.
+   Copyright 2003 Free Software Foundation, Inc.
+
+This file is part of GNU CC.
+
+GNU CC 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.
+
+GNU CC 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 GNU CC; see the file COPYING.  If not, write to
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+#ifndef GCC_HOST_HOOKS_H
+#define GCC_HOST_HOOKS_H
+
+struct host_hooks 
+{
+  void (*extra_signals) PARAMS((void));
+
+  /* Whenever you add entries here, make sure you adjust hosthooks-def.h.  */
+};
+
+/* Each host provides its own.  */
+extern const struct host_hooks host_hooks;
+
+#endif /* GCC_LANG_HOOKS_H */

gcc/toplev.c

@@ -74,6 +74,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "langhooks.h"
 #include "cfglayout.h"
 #include "cfgloop.h"
+#include "hosthooks.h"
 
 #if defined (DWARF2_UNWIND_INFO) || defined (DWARF2_DEBUGGING_INFO)
 #include "dwarf2out.h"
@@ -4759,6 +4760,9 @@ general_init (argv0)
   signal (SIGFPE, crash_signal);
 #endif
 
+  /* Other host-specific signal setup.  */
+  (*host_hooks.extra_signals)();
+
   /* Initialize the diagnostics reporting machinery, so option parsing
      can give warnings and errors.  */
   diagnostic_initialize (global_dc);