--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/config/darwin-driver.c	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,159 @@
+/* Additional functions for the GCC driver on Darwin native.
+   Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc.
+   Contributed by Apple Computer 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 3, 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 COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef CROSS_DIRECTORY_STRUCTURE
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "gcc.h"
+#include <sys/sysctl.h>
+#include "xregex.h"
+
+#ifndef SWITCH_TAKES_ARG
+#define SWITCH_TAKES_ARG(CHAR) DEFAULT_SWITCH_TAKES_ARG(CHAR)
+#endif
+
+#ifndef WORD_SWITCH_TAKES_ARG
+#define WORD_SWITCH_TAKES_ARG(STR) DEFAULT_WORD_SWITCH_TAKES_ARG (STR)
+#endif
+
+/* When running on a Darwin system and using that system's headers and
+   libraries, default the -mmacosx-version-min flag to be the version
+   of the system on which the compiler is running.  */
+
+void
+darwin_default_min_version (int * argc_p, char *** argv_p)
+{
+  const int argc = *argc_p;
+  char ** const argv = *argv_p;
+  int i;
+  char osversion[32];
+  size_t osversion_len = sizeof (osversion) - 1;
+  static int osversion_name[2] = { CTL_KERN, KERN_OSRELEASE };
+  char * version_p;
+  char * version_pend;
+  int major_vers;
+  char minor_vers[6];
+  static char new_flag[sizeof ("-mmacosx-version-min=10.0.0") + 6];
+
+  /* If the command-line is empty, just return.  */
+  if (argc <= 1)
+    return;
+  /* Don't do this if the user has specified -b or -V at the start
+     of the command-line.  */
+  if (argv[1][0] == '-'
+      && (argv[1][1] == 'V' ||
+	  ((argv[1][1] == 'b') && (NULL != strchr(argv[1] + 2,'-')))))
+    return;
+  
+  /* Don't do this if the user specified -mmacosx-version-min= or
+     -mno-macosx-version-min.  */
+  for (i = 1; i < argc; i++)
+    if (argv[i][0] == '-')
+      {
+	const char * const p = argv[i];
+	if (strncmp (p, "-mno-macosx-version-min", 23) == 0
+	    || strncmp (p, "-mmacosx-version-min", 20) == 0)
+	  return;
+	
+	/* It doesn't count if it's an argument to a different switch.  */
+	if (p[0] == '-'
+	    && ((SWITCH_TAKES_ARG (p[1]) > (p[2] != 0))
+		|| WORD_SWITCH_TAKES_ARG (p + 1)))
+	  i++;
+      }
+
+  /* Retrieve the deployment target from the environment and insert
+     it as a flag.  */
+  {
+    const char * macosx_deployment_target;
+    macosx_deployment_target = getenv ("MACOSX_DEPLOYMENT_TARGET");
+    if (macosx_deployment_target
+	/* Apparently, an empty string for MACOSX_DEPLOYMENT_TARGET means
+	   "use the default".  Or, possibly "use 10.1".  We choose
+	   to ignore the environment variable, as if it was never set.  */
+	&& macosx_deployment_target[0])
+      {
+	++*argc_p;
+	*argv_p = XNEWVEC (char *, *argc_p);
+	(*argv_p)[0] = argv[0];
+	(*argv_p)[1] = concat ("-mmacosx-version-min=",
+			       macosx_deployment_target, NULL);
+	memcpy (*argv_p + 2, argv + 1, (argc - 1) * sizeof (char *));
+	return;
+      }
+  }
+
+  /* Determine the version of the running OS.  If we can't, warn user,
+     and do nothing.  */
+  if (sysctl (osversion_name, ARRAY_SIZE (osversion_name), osversion,
+	      &osversion_len, NULL, 0) == -1)
+    {
+      fprintf (stderr, "sysctl for kern.osversion failed: %s\n",
+	       xstrerror (errno));
+      return;
+    }
+
+  /* Try to parse the first two parts of the OS version number.  Warn
+     user and return if it doesn't make sense.  */
+  if (! ISDIGIT (osversion[0]))
+    goto parse_failed;
+  major_vers = osversion[0] - '0';
+  version_p = osversion + 1;
+  if (ISDIGIT (*version_p))
+    major_vers = major_vers * 10 + (*version_p++ - '0');
+  if (major_vers > 4 + 9)
+    goto parse_failed;
+  if (*version_p++ != '.')
+    goto parse_failed;
+  version_pend = strchr(version_p, '.');
+  if (!version_pend)
+    goto parse_failed;
+  if (! ISDIGIT (*version_p))
+    goto parse_failed;
+  strncpy(minor_vers, version_p, version_pend - version_p);
+  minor_vers[version_pend - version_p] = '\0';
+  
+  /* The major kernel version number is 4 plus the second OS version
+     component.  */
+  if (major_vers - 4 <= 4)
+    /* On 10.4 and earlier, the old linker is used which does not
+       support three-component system versions.  */
+    sprintf (new_flag, "-mmacosx-version-min=10.%d", major_vers - 4);
+  else
+    sprintf (new_flag, "-mmacosx-version-min=10.%d.%s", major_vers - 4,
+	     minor_vers);
+
+  /* Add the new flag.  */
+  ++*argc_p;
+  *argv_p = XNEWVEC (char *, *argc_p);
+  (*argv_p)[0] = argv[0];
+  (*argv_p)[1] = new_flag;
+  memcpy (*argv_p + 2, argv + 1, (argc - 1) * sizeof (char *));
+  return;
+  
+ parse_failed:
+  fprintf (stderr, "couldn't understand kern.osversion `%.*s'\n",
+	   (int) osversion_len, osversion);
+  return;
+}
+
+#endif /* CROSS_DIRECTORY_STRUCTURE */