--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/file-find.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,210 @@
+/* Utility functions for finding files relative to GCC binaries.
+   Copyright (C) 1992-2017 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 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/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "filenames.h"
+#include "file-find.h"
+
+static bool debug = false;
+
+void
+find_file_set_debug (bool debug_state)
+{
+  debug = debug_state;
+}
+
+char *
+find_a_file (struct path_prefix *pprefix, const char *name, int mode)
+{
+  char *temp;
+  struct prefix_list *pl;
+  int len = pprefix->max_len + strlen (name) + 1;
+
+  if (debug)
+    fprintf (stderr, "Looking for '%s'\n", name);
+
+#ifdef HOST_EXECUTABLE_SUFFIX
+  len += strlen (HOST_EXECUTABLE_SUFFIX);
+#endif
+
+  temp = XNEWVEC (char, len);
+
+  /* Determine the filename to execute (special case for absolute paths).  */
+
+  if (IS_ABSOLUTE_PATH (name))
+    {
+      if (access (name, mode) == 0)
+	{
+	  strcpy (temp, name);
+
+	  if (debug)
+	    fprintf (stderr, "  - found: absolute path\n");
+
+	  return temp;
+	}
+
+#ifdef HOST_EXECUTABLE_SUFFIX
+	/* Some systems have a suffix for executable files.
+	   So try appending that.  */
+      strcpy (temp, name);
+	strcat (temp, HOST_EXECUTABLE_SUFFIX);
+
+	if (access (temp, mode) == 0)
+	  return temp;
+#endif
+
+      if (debug)
+	fprintf (stderr, "  - failed to locate using absolute path\n");
+    }
+  else
+    for (pl = pprefix->plist; pl; pl = pl->next)
+      {
+	struct stat st;
+
+	strcpy (temp, pl->prefix);
+	strcat (temp, name);
+
+	if (stat (temp, &st) >= 0
+	    && ! S_ISDIR (st.st_mode)
+	    && access (temp, mode) == 0)
+	  return temp;
+
+#ifdef HOST_EXECUTABLE_SUFFIX
+	/* Some systems have a suffix for executable files.
+	   So try appending that.  */
+	strcat (temp, HOST_EXECUTABLE_SUFFIX);
+
+	if (stat (temp, &st) >= 0
+	    && ! S_ISDIR (st.st_mode)
+	    && access (temp, mode) == 0)
+	  return temp;
+#endif
+      }
+
+  if (debug && pprefix->plist == NULL)
+    fprintf (stderr, "  - failed: no entries in prefix list\n");
+
+  free (temp);
+  return 0;
+}
+
+/* Add an entry for PREFIX to prefix list PREFIX.
+   Add at beginning if FIRST is true.  */
+
+void
+do_add_prefix (struct path_prefix *pprefix, const char *prefix, bool first)
+{
+  struct prefix_list *pl, **prev;
+  int len;
+
+  if (pprefix->plist && !first)
+    {
+      for (pl = pprefix->plist; pl->next; pl = pl->next)
+	;
+      prev = &pl->next;
+    }
+  else
+    prev = &pprefix->plist;
+
+  /* Keep track of the longest prefix.  */
+
+  len = strlen (prefix);
+  if (len > pprefix->max_len)
+    pprefix->max_len = len;
+
+  pl = XNEW (struct prefix_list);
+  pl->prefix = xstrdup (prefix);
+
+  if (*prev)
+    pl->next = *prev;
+  else
+    pl->next = (struct prefix_list *) 0;
+  *prev = pl;
+}
+
+/* Add an entry for PREFIX at the end of prefix list PREFIX.  */
+
+void
+add_prefix (struct path_prefix *pprefix, const char *prefix)
+{
+  do_add_prefix (pprefix, prefix, false);
+}
+
+/* Add an entry for PREFIX at the begin of prefix list PREFIX.  */
+
+void
+add_prefix_begin (struct path_prefix *pprefix, const char *prefix)
+{
+  do_add_prefix (pprefix, prefix, true);
+}
+
+/* Take the value of the environment variable ENV, break it into a path, and
+   add of the entries to PPREFIX.  */
+
+void
+prefix_from_env (const char *env, struct path_prefix *pprefix)
+{
+  const char *p;
+  p = getenv (env);
+
+  if (p)
+    prefix_from_string (p, pprefix);
+}
+
+void
+prefix_from_string (const char *p, struct path_prefix *pprefix)
+{
+  const char *startp, *endp;
+  char *nstore = XNEWVEC (char, strlen (p) + 3);
+
+  if (debug)
+    fprintf (stderr, "Convert string '%s' into prefixes, separator = '%c'\n", p, PATH_SEPARATOR);
+
+  startp = endp = p;
+  while (1)
+    {
+      if (*endp == PATH_SEPARATOR || *endp == 0)
+	{
+	  strncpy (nstore, startp, endp-startp);
+	  if (endp == startp)
+	    {
+	      strcpy (nstore, "./");
+	    }
+	  else if (! IS_DIR_SEPARATOR (endp[-1]))
+	    {
+	      nstore[endp-startp] = DIR_SEPARATOR;
+	      nstore[endp-startp+1] = 0;
+	    }
+	  else
+	    nstore[endp-startp] = 0;
+
+	  if (debug)
+	    fprintf (stderr, "  - add prefix: %s\n", nstore);
+
+	  add_prefix (pprefix, nstore);
+	  if (*endp == 0)
+	    break;
+	  endp = startp = endp + 1;
+	}
+      else
+	endp++;
+    }
+  free (nstore);
+}