--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libcc1/findcomp.cc	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,140 @@
+/* Find the correct compiler.
+   Copyright (C) 2014-2017 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 <string>
+#include <dirent.h>
+#include <stdlib.h>
+
+#include "libiberty.h"
+#include "xregex.h"
+#include "findcomp.hh"
+#include "system.h"
+
+class scanner
+{
+public:
+
+  scanner (const std::string &dir)
+  {
+    m_dir = opendir (dir.c_str ());
+  }
+
+  ~scanner ()
+  {
+    if (m_dir != NULL)
+      closedir (m_dir);
+  }
+
+  const char *next ()
+  {
+    if (m_dir == NULL)
+      return NULL;
+
+    struct dirent *entry = readdir (m_dir);
+    if (entry == NULL)
+      return NULL;
+
+    return entry->d_name;
+  }
+
+private:
+
+  DIR *m_dir;
+};
+
+static bool
+search_dir (const regex_t &regexp, const std::string &dir, std::string *result)
+{
+  scanner scan (dir);
+  const char *filename;
+
+  while ((filename = scan.next ()) != NULL)
+    {
+      if (regexec (&regexp, filename, 0, NULL, 0) == 0)
+	{
+	  *result = dir + DIR_SEPARATOR + filename;
+	  return true;
+	}
+    }
+
+  return false;
+}
+
+class tokenizer
+{
+public:
+
+  tokenizer (const char *str)
+    : m_str (str),
+      m_pos (0)
+  {
+  }
+
+  bool done () const
+  {
+    return m_pos == std::string::npos;
+  }
+
+  std::string next ()
+  {
+    std::string::size_type last_pos = m_pos;
+    std::string::size_type colon = m_str.find(':', last_pos);
+
+    std::string result;
+    if (colon == std::string::npos)
+      {
+	m_pos = colon;
+	result = m_str.substr(last_pos, colon);
+      }
+    else
+      {
+	m_pos = colon + 1;
+	result = m_str.substr(last_pos, colon - last_pos);
+      }
+    if (result == "")
+      result = ".";
+
+    return result;
+  }
+
+private:
+
+  std::string m_str;
+  std::string::size_type m_pos;
+};
+
+bool
+find_compiler (const regex_t &regexp, std::string *result)
+{
+  const char *cpath = getenv ("PATH");
+
+  if (cpath == NULL)
+    return false;
+
+  tokenizer dirs (cpath);
+  while (!dirs.done ())
+    {
+      std::string dir = dirs.next ();
+      if (search_dir (regexp, dir, result))
+	return true;
+    }
+
+  return false;
+}