--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/prefix.c	Fri Jul 17 14:47:48 2009 +0900
@@ -0,0 +1,356 @@
+/* Utility to update paths from internal to external forms.
+   Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
+   2007  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 Library General Public License as published by
+the Free Software Foundation; either version 3 of the License, 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+/* This file contains routines to update a path, both to canonicalize
+   the directory format and to handle any prefix translation.
+
+   This file must be compiled with -DPREFIX= to specify the "prefix"
+   value used by configure.  If a filename does not begin with this
+   prefix, it will not be affected other than by directory canonicalization.
+
+   Each caller of 'update_path' may specify both a filename and
+   a translation prefix and consist of the name of the package that contains
+   the file ("@GCC", "@BINUTIL", "@GNU", etc).
+
+   If the prefix is not specified, the filename will only undergo
+   directory canonicalization.
+
+   If it is specified, the string given by PREFIX will be replaced
+   by the specified prefix (with a '@' in front unless the prefix begins
+   with a '$') and further translation will be done as follows
+   until none of the two conditions below are met:
+
+   1) If the filename begins with '@', the string between the '@' and
+   the end of the name or the first '/' or directory separator will
+   be considered a "key" and looked up as follows:
+
+   -- If this is a Win32 OS, then the Registry will be examined for
+      an entry of "key" in
+
+      HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\<KEY>
+
+      if found, that value will be used. <KEY> defaults to GCC version
+      string, but can be overridden at configuration time.
+
+   -- If not found (or not a Win32 OS), the environment variable
+      key_ROOT (the value of "key" concatenated with the constant "_ROOT")
+      is tried.  If that fails, then PREFIX (see above) is used.
+
+   2) If the filename begins with a '$', the rest of the string up
+   to the end or the first '/' or directory separator will be used
+   as an environment variable, whose value will be returned.
+
+   Once all this is done, any '/' will be converted to DIR_SEPARATOR,
+   if they are different.
+
+   NOTE:  using resolve_keyed_path under Win32 requires linking with
+   advapi32.dll.  */
+
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
+#include <windows.h>
+#endif
+#include "prefix.h"
+
+static const char *std_prefix = PREFIX;
+
+static const char *get_key_value (char *);
+static char *translate_name (char *);
+static char *save_string (const char *, int);
+static void tr (char *, int, int);
+
+#if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
+static char *lookup_key (char *);
+static HKEY reg_key = (HKEY) INVALID_HANDLE_VALUE;
+#endif
+
+/* Given KEY, as above, return its value.  */
+
+static const char *
+get_key_value (char *key)
+{
+  const char *prefix = 0;
+  char *temp = 0;
+
+#if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
+  prefix = lookup_key (key);
+#endif
+
+  if (prefix == 0)
+    prefix = getenv (temp = concat (key, "_ROOT", NULL));
+
+  if (prefix == 0)
+    prefix = std_prefix;
+
+  if (temp)
+    free (temp);
+
+  return prefix;
+}
+
+/* Return a copy of a string that has been placed in the heap.  */
+
+static char *
+save_string (const char *s, int len)
+{
+  char *result = XNEWVEC (char, len + 1);
+
+  memcpy (result, s, len);
+  result[len] = 0;
+  return result;
+}
+
+#if defined(_WIN32) && defined(ENABLE_WIN32_REGISTRY)
+
+#ifndef WIN32_REGISTRY_KEY
+# define WIN32_REGISTRY_KEY BASEVER
+#endif
+
+/* Look up "key" in the registry, as above.  */
+
+static char *
+lookup_key (char *key)
+{
+  char *dst;
+  DWORD size;
+  DWORD type;
+  LONG res;
+
+  if (reg_key == (HKEY) INVALID_HANDLE_VALUE)
+    {
+      res = RegOpenKeyExA (HKEY_LOCAL_MACHINE, "SOFTWARE", 0,
+			   KEY_READ, &reg_key);
+
+      if (res == ERROR_SUCCESS)
+	res = RegOpenKeyExA (reg_key, "Free Software Foundation", 0,
+			     KEY_READ, &reg_key);
+
+      if (res == ERROR_SUCCESS)
+	res = RegOpenKeyExA (reg_key, WIN32_REGISTRY_KEY, 0,
+			     KEY_READ, &reg_key);
+
+      if (res != ERROR_SUCCESS)
+	{
+	  reg_key = (HKEY) INVALID_HANDLE_VALUE;
+	  return 0;
+	}
+    }
+
+  size = 32;
+  dst = xmalloc (size);
+
+  res = RegQueryValueExA (reg_key, key, 0, &type, (LPBYTE) dst, &size);
+  if (res == ERROR_MORE_DATA && type == REG_SZ)
+    {
+      dst = xrealloc (dst, size);
+      res = RegQueryValueExA (reg_key, key, 0, &type, (LPBYTE) dst, &size);
+    }
+
+  if (type != REG_SZ || res != ERROR_SUCCESS)
+    {
+      free (dst);
+      dst = 0;
+    }
+
+  return dst;
+}
+#endif
+
+/* If NAME, a malloc-ed string, starts with a '@' or '$', apply the
+   translation rules above and return a newly malloc-ed name.
+   Otherwise, return the given name.  */
+
+static char *
+translate_name (char *name)
+{
+  char code;
+  char *key, *old_name;
+  const char *prefix;
+  int keylen;
+
+  for (;;)
+    {
+      code = name[0];
+      if (code != '@' && code != '$')
+	break;
+
+      for (keylen = 0;
+	   (name[keylen + 1] != 0 && !IS_DIR_SEPARATOR (name[keylen + 1]));
+	   keylen++)
+	;
+
+      key = (char *) alloca (keylen + 1);
+      strncpy (key, &name[1], keylen);
+      key[keylen] = 0;
+
+      if (code == '@')
+	{
+	  prefix = get_key_value (key);
+	  if (prefix == 0)
+	    prefix = std_prefix;
+	}
+      else
+	prefix = getenv (key);
+
+      if (prefix == 0)
+	prefix = PREFIX;
+
+      /* We used to strip trailing DIR_SEPARATORs here, but that can
+	 sometimes yield a result with no separator when one was coded
+	 and intended by the user, causing two path components to run
+	 together.  */
+
+      old_name = name;
+      name = concat (prefix, &name[keylen + 1], NULL);
+      free (old_name);
+    }
+
+  return name;
+}
+
+/* In a NUL-terminated STRING, replace character C1 with C2 in-place.  */
+static void
+tr (char *string, int c1, int c2)
+{
+  do
+    {
+      if (*string == c1)
+	*string = c2;
+    }
+  while (*string++);
+}
+
+/* Update PATH using KEY if PATH starts with PREFIX as a directory.
+   The returned string is always malloc-ed, and the caller is
+   responsible for freeing it.  */
+
+char *
+update_path (const char *path, const char *key)
+{
+  char *result, *p;
+  const int len = strlen (std_prefix);
+
+  if (! strncmp (path, std_prefix, len)
+      && (IS_DIR_SEPARATOR(path[len])
+          || path[len] == '\0')
+      && key != 0)
+    {
+      bool free_key = false;
+
+      if (key[0] != '$')
+	{
+	  key = concat ("@", key, NULL);
+	  free_key = true;
+	}
+
+      result = concat (key, &path[len], NULL);
+      if (free_key)
+	free (CONST_CAST (char *, key));
+      result = translate_name (result);
+    }
+  else
+    result = xstrdup (path);
+
+#ifndef ALWAYS_STRIP_DOTDOT
+#define ALWAYS_STRIP_DOTDOT 0
+#endif
+
+  p = result;
+  while (1)
+    {
+      char *src, *dest;
+
+      p = strchr (p, '.');
+      if (p == NULL)
+	break;
+      /* Look for `/../'  */
+      if (p[1] == '.'
+	  && IS_DIR_SEPARATOR (p[2])
+	  && (p != result && IS_DIR_SEPARATOR (p[-1])))
+	{
+	  *p = 0;
+	  if (!ALWAYS_STRIP_DOTDOT && access (result, X_OK) == 0)
+	    {
+	      *p = '.';
+	      break;
+	    }
+	  else
+	    {
+	      /* We can't access the dir, so we won't be able to
+		 access dir/.. either.  Strip out `dir/../'.  If `dir'
+		 turns out to be `.', strip one more path component.  */
+	      dest = p;
+	      do
+		{
+		  --dest;
+		  while (dest != result && IS_DIR_SEPARATOR (*dest))
+		    --dest;
+		  while (dest != result && !IS_DIR_SEPARATOR (dest[-1]))
+		    --dest;
+		}
+	      while (dest != result && *dest == '.');
+	      /* If we have something like `./..' or `/..', don't
+		 strip anything more.  */
+	      if (*dest == '.' || IS_DIR_SEPARATOR (*dest))
+		{
+		  *p = '.';
+		  break;
+		}
+	      src = p + 3;
+	      while (IS_DIR_SEPARATOR (*src))
+		++src;
+	      p = dest;
+	      while ((*dest++ = *src++) != 0)
+		;
+	    }
+	}
+      else
+	++p;
+    }
+
+#ifdef UPDATE_PATH_HOST_CANONICALIZE
+  /* Perform host dependent canonicalization when needed.  */
+  UPDATE_PATH_HOST_CANONICALIZE (result);
+#endif
+
+#ifdef DIR_SEPARATOR_2
+  /* Convert DIR_SEPARATOR_2 to DIR_SEPARATOR.  */
+  if (DIR_SEPARATOR_2 != DIR_SEPARATOR)
+    tr (result, DIR_SEPARATOR_2, DIR_SEPARATOR);
+#endif
+
+#if defined (DIR_SEPARATOR) && !defined (DIR_SEPARATOR_2)
+  if (DIR_SEPARATOR != '/')
+    tr (result, '/', DIR_SEPARATOR);
+#endif
+
+  return result;
+}
+
+/* Reset the standard prefix.  */
+void
+set_std_prefix (const char *prefix, int len)
+{
+  std_prefix = save_string (prefix, len);
+}