text: /* 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"
  
  #ifndef PREFIX
  # define PREFIX "/usr/local"
  #endif
  
  #ifndef IS_DIR_SEPARATOR
  # define IS_DIR_SEPARATOR(C) ((C) == '/' || (C) == '\\')
  #endif
  
  #define concat internal_concat
  
  #ifndef XNEWVEC
  # define XNEWVEC(T,N) ((T*) xmalloc (sizeof (T) * (N)))
  #endif
  
  void* xmalloc (size_t size)
  {
    return malloc (size);
  }
  
  char* xstrdup (const char* s)
  {
    /* The xstrdup real version checks the result and aborts... */
    return strdup (s);
  }
  
  static char* concat(const char* first, const char* second, const char* last)
  {
    size_t len = strlen (first) + strlen (second);
    char* result = malloc (len + 1);
  
    strcpy (result, first);
    strcat (result, second);
    
    return result;
  }
  
  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);
  }
  