Virgin import of the GCC 2.95.1 compilers

1 files changed, 1605 insertions, 0 deletions

diff --git a/contrib/gcc/cppfiles.c b/contrib/gcc/cppfiles.c
new file mode 100644
index 0000000..a63d7e5
--- /dev/null
+++ b/contrib/gcc/cppfiles.c
@@ -0,0 +1,1605 @@
+/* Part of CPP library.  (include file handling)
+   Copyright (C) 1986, 87, 89, 92 - 95, 98, 1999 Free Software Foundation, Inc.
+   Written by Per Bothner, 1994.
+   Based on CCCP program by Paul Rubin, June 1986
+   Adapted to ANSI C, Richard Stallman, Jan 1987
+   Split out of cpplib.c, Zack Weinberg, Oct 1998
+
+This program 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 2, or (at your option) any
+later version.
+
+This program 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 this program; if not, write to the Free Software
+Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+ In other words, you are welcome to use, share and improve this program.
+ You are forbidden to forbid anyone else to use, share and improve
+ what you give them.   Help stamp out software-hoarding!  */
+
+#include "config.h"
+#include "system.h"
+#include "cpplib.h"
+
+/* The entry points to this file are: find_include_file, finclude,
+   include_hash, append_include_chain, deps_output, and file_cleanup.
+   file_cleanup is only called through CPP_BUFFER(pfile)->cleanup,
+   so it's static anyway. */
+
+static struct include_hash *redundant_include_p
+					PROTO ((cpp_reader *,
+						struct include_hash *,
+						struct file_name_list *));
+static struct file_name_map *read_name_map	PROTO ((cpp_reader *,
+							const char *));
+static char *read_filename_string	PROTO ((int, FILE *));
+static char *remap_filename 		PROTO ((cpp_reader *, char *,
+						struct file_name_list *));
+static long read_and_prescan		PROTO ((cpp_reader *, cpp_buffer *,
+						int, size_t));
+static struct file_name_list *actual_directory PROTO ((cpp_reader *, char *));
+
+static void initialize_input_buffer	PROTO ((cpp_reader *, int,
+						struct stat *));
+
+#if 0
+static void hack_vms_include_specification PROTO ((char *));
+#endif
+
+/* Windows does not natively support inodes, and neither does MSDOS.
+   VMS has non-numeric inodes. */
+#ifdef VMS
+#define INO_T_EQ(a, b) (!bcmp((char *) &(a), (char *) &(b), sizeof (a)))
+#elif (defined _WIN32 && !defined CYGWIN && ! defined (_UWIN)) \
+       || defined __MSDOS__
+#define INO_T_EQ(a, b) 0
+#else
+#define INO_T_EQ(a, b) ((a) == (b))
+#endif
+
+/* Merge the four include chains together in the order quote, bracket,
+   system, after.  Remove duplicate dirs (as determined by
+   INO_T_EQ()).  The system_include and after_include chains are never
+   referred to again after this function; all access is through the
+   bracket_include path.
+
+   For the future: Check if the directory is empty (but
+   how?) and possibly preload the include hash. */
+
+void
+merge_include_chains (opts)
+     struct cpp_options *opts;
+{
+  struct file_name_list *prev, *cur, *other;
+  struct file_name_list *quote, *brack, *systm, *after;
+  struct file_name_list *qtail, *btail, *stail, *atail;
+
+  qtail = opts->pending->quote_tail;
+  btail = opts->pending->brack_tail;
+  stail = opts->pending->systm_tail;
+  atail = opts->pending->after_tail;
+
+  quote = opts->pending->quote_head;
+  brack = opts->pending->brack_head;
+  systm = opts->pending->systm_head;
+  after = opts->pending->after_head;
+
+  /* Paste together bracket, system, and after include chains. */
+  if (stail)
+    stail->next = after;
+  else
+    systm = after;
+  if (btail)
+    btail->next = systm;
+  else
+    brack = systm;
+
+  /* This is a bit tricky.
+     First we drop dupes from the quote-include list.
+     Then we drop dupes from the bracket-include list.
+     Finally, if qtail and brack are the same directory,
+     we cut out qtail.
+
+     We can't just merge the lists and then uniquify them because
+     then we may lose directories from the <> search path that should
+     be there; consider -Ifoo -Ibar -I- -Ifoo -Iquux. It is however
+     safe to treat -Ibar -Ifoo -I- -Ifoo -Iquux as if written
+     -Ibar -I- -Ifoo -Iquux.
+
+     Note that this algorithm is quadratic in the number of -I switches,
+     which is acceptable since there aren't usually that many of them.  */
+
+  for (cur = quote, prev = NULL; cur; cur = cur->next)
+    {
+      for (other = quote; other != cur; other = other->next)
+        if (INO_T_EQ (cur->ino, other->ino)
+	    && cur->dev == other->dev)
+          {
+	    if (opts->verbose)
+	      cpp_notice ("ignoring duplicate directory `%s'\n", cur->name);
+
+	    prev->next = cur->next;
+	    free (cur->name);
+	    free (cur);
+	    cur = prev;
+	    break;
+	  }
+      prev = cur;
+    }
+  qtail = prev;
+
+  for (cur = brack; cur; cur = cur->next)
+    {
+      for (other = brack; other != cur; other = other->next)
+        if (INO_T_EQ (cur->ino, other->ino)
+	    && cur->dev == other->dev)
+          {
+	    if (opts->verbose)
+	      cpp_notice ("ignoring duplicate directory `%s'\n", cur->name);
+
+	    prev->next = cur->next;
+	    free (cur->name);
+	    free (cur);
+	    cur = prev;
+	    break;
+	  }
+      prev = cur;
+    }
+
+  if (quote)
+    {
+      if (INO_T_EQ (qtail->ino, brack->ino) && qtail->dev == brack->dev)
+        {
+	  if (quote == qtail)
+	    {
+	      if (opts->verbose)
+		cpp_notice ("ignoring duplicate directory `%s'\n",
+			    quote->name);
+
+	      free (quote->name);
+	      free (quote);
+	      quote = brack;
+	    }
+	  else
+	    {
+	      cur = quote;
+	      while (cur->next != qtail)
+		  cur = cur->next;
+	      cur->next = brack;
+	      if (opts->verbose)
+		cpp_notice ("ignoring duplicate directory `%s'\n",
+			    qtail->name);
+
+	      free (qtail->name);
+	      free (qtail);
+	    }
+	}
+      else
+	  qtail->next = brack;
+    }
+  else
+      quote = brack;
+
+  opts->quote_include = quote;
+  opts->bracket_include = brack;
+}
+
+/* Look up or add an entry to the table of all includes.  This table
+ is indexed by the name as it appears in the #include line.  The
+ ->next_this_file chain stores all different files with the same
+ #include name (there are at least three ways this can happen).  The
+ hash function could probably be improved a bit. */
+
+struct include_hash *
+include_hash (pfile, fname, add)
+     cpp_reader *pfile;
+     char *fname;
+     int add;
+{
+  unsigned int hash = 0;
+  struct include_hash *l, *m;
+  char *f = fname;
+
+  while (*f)
+    hash += *f++;
+
+  l = pfile->all_include_files[hash % ALL_INCLUDE_HASHSIZE];
+  m = 0;
+  for (; l; m = l, l = l->next)
+    if (!strcmp (l->nshort, fname))
+      return l;
+
+  if (!add)
+    return 0;
+  
+  l = (struct include_hash *) xmalloc (sizeof (struct include_hash));
+  l->next = NULL;
+  l->next_this_file = NULL;
+  l->foundhere = NULL;
+  l->buf = NULL;
+  l->limit = NULL;
+  if (m)
+    m->next = l;
+  else
+    pfile->all_include_files[hash % ALL_INCLUDE_HASHSIZE] = l;
+  
+  return l;
+}
+
+/* Return 0 if the file pointed to by IHASH has never been included before,
+         -1 if it has been included before and need not be again,
+	 or a pointer to an IHASH entry which is the file to be reread.
+   "Never before" is with respect to the position in ILIST.
+
+   This will not detect redundancies involving odd uses of the
+   `current directory' rule for "" includes.  They aren't quite
+   pathological, but I think they are rare enough not to worry about.
+   The simplest example is:
+
+   top.c:
+   #include "a/a.h"
+   #include "b/b.h"
+
+   a/a.h:
+   #include "../b/b.h"
+
+   and the problem is that for `current directory' includes,
+   ihash->foundhere is not on any of the global include chains,
+   so the test below (i->foundhere == l) may be false even when
+   the directories are in fact the same.  */
+
+static struct include_hash *
+redundant_include_p (pfile, ihash, ilist)
+     cpp_reader *pfile;
+     struct include_hash *ihash;
+     struct file_name_list *ilist;
+{
+  struct file_name_list *l;
+  struct include_hash *i;
+
+  if (! ihash->foundhere)
+    return 0;
+
+  for (i = ihash; i; i = i->next_this_file)
+    for (l = ilist; l; l = l->next)
+       if (i->foundhere == l)
+	 /* The control_macro works like this: If it's NULL, the file
+	    is to be included again.  If it's "", the file is never to
+	    be included again.  If it's a string, the file is not to be
+	    included again if the string is the name of a defined macro. */
+	 return (i->control_macro
+		 && (i->control_macro[0] == '\0'
+		     || cpp_lookup (pfile, i->control_macro, -1, -1)))
+	     ? (struct include_hash *)-1 : i;
+
+  return 0;
+}
+
+static int
+file_cleanup (pbuf, pfile)
+     cpp_buffer *pbuf;
+     cpp_reader *pfile;
+{
+  if (pbuf->buf)
+    {
+      free (pbuf->buf);
+      pbuf->buf = 0;
+    }
+  if (pfile->system_include_depth)
+    pfile->system_include_depth--;
+  return 0;
+}
+
+/* Search for include file FNAME in the include chain starting at
+   SEARCH_START.  Return -2 if this file doesn't need to be included
+   (because it was included already and it's marked idempotent),
+   -1 if an error occurred, or a file descriptor open on the file.
+   *IHASH is set to point to the include hash entry for this file, and
+   *BEFORE is 1 if the file was included before (but needs to be read
+   again). */
+int
+find_include_file (pfile, fname, search_start, ihash, before)
+     cpp_reader *pfile;
+     char *fname;
+     struct file_name_list *search_start;
+     struct include_hash **ihash;
+     int *before;
+{
+  struct file_name_list *l;
+  struct include_hash *ih, *jh;
+  int f, len;
+  char *name;
+  
+  ih = include_hash (pfile, fname, 1);
+  jh = redundant_include_p (pfile, ih,
+			    fname[0] == '/' ? ABSOLUTE_PATH : search_start);
+
+  if (jh != 0)
+    {
+      *before = 1;
+      *ihash = jh;
+
+      if (jh == (struct include_hash *)-1)
+	return -2;
+      else
+	return open (jh->name, O_RDONLY, 0666);
+    }
+
+  if (ih->foundhere)
+    /* A file is already known by this name, but it's not the same file.
+       Allocate another include_hash block and add it to the next_this_file
+       chain. */
+    {
+      jh = (struct include_hash *)xmalloc (sizeof (struct include_hash));
+      while (ih->next_this_file) ih = ih->next_this_file;
+
+      ih->next_this_file = jh;
+      jh = ih;
+      ih = ih->next_this_file;
+
+      ih->next = NULL;
+      ih->next_this_file = NULL;
+      ih->buf = NULL;
+      ih->limit = NULL;
+    }
+  *before = 0;
+  *ihash = ih;
+  ih->nshort = xstrdup (fname);
+  ih->control_macro = NULL;
+  
+  /* If the pathname is absolute, just open it. */ 
+  if (fname[0] == '/')
+    {
+      ih->foundhere = ABSOLUTE_PATH;
+      ih->name = ih->nshort;
+      return open (ih->name, O_RDONLY, 0666);
+    }
+
+  /* Search directory path, trying to open the file. */
+
+  len = strlen (fname);
+  name = xmalloc (len + pfile->max_include_len + 2 + INCLUDE_LEN_FUDGE);
+
+  for (l = search_start; l; l = l->next)
+    {
+      bcopy (l->name, name, l->nlen);
+      name[l->nlen] = '/';
+      strcpy (&name[l->nlen+1], fname);
+      simplify_pathname (name);
+      if (CPP_OPTIONS (pfile)->remap)
+	name = remap_filename (pfile, name, l);
+
+      f = open (name, O_RDONLY|O_NONBLOCK|O_NOCTTY, 0666);
+#ifdef EACCES
+      if (f == -1 && errno == EACCES)
+	{
+	  cpp_error(pfile, "included file `%s' exists but is not readable",
+		    name);
+	  return -1;
+	}
+#endif
+
+      if (f >= 0)
+        {
+	  ih->foundhere = l;
+	  ih->name = xrealloc (name, strlen (name)+1);
+	  return f;
+        }
+    }
+  
+    if (jh)
+      {
+	jh->next_this_file = NULL;
+	free (ih);
+      }
+    free (name);
+    *ihash = (struct include_hash *)-1;
+    return -1;
+}
+
+/* The file_name_map structure holds a mapping of file names for a
+   particular directory.  This mapping is read from the file named
+   FILE_NAME_MAP_FILE in that directory.  Such a file can be used to
+   map filenames on a file system with severe filename restrictions,
+   such as DOS.  The format of the file name map file is just a series
+   of lines with two tokens on each line.  The first token is the name
+   to map, and the second token is the actual name to use.  */
+
+struct file_name_map
+{
+  struct file_name_map *map_next;
+  char *map_from;
+  char *map_to;
+};
+
+#define FILE_NAME_MAP_FILE "header.gcc"
+
+/* Read a space delimited string of unlimited length from a stdio
+   file.  */
+
+static char *
+read_filename_string (ch, f)
+     int ch;
+     FILE *f;
+{
+  char *alloc, *set;
+  int len;
+
+  len = 20;
+  set = alloc = xmalloc (len + 1);
+  if (! is_space[ch])
+    {
+      *set++ = ch;
+      while ((ch = getc (f)) != EOF && ! is_space[ch])
+	{
+	  if (set - alloc == len)
+	    {
+	      len *= 2;
+	      alloc = xrealloc (alloc, len + 1);
+	      set = alloc + len / 2;
+	    }
+	  *set++ = ch;
+	}
+    }
+  *set = '\0';
+  ungetc (ch, f);
+  return alloc;
+}
+
+/* This structure holds a linked list of file name maps, one per directory.  */
+
+struct file_name_map_list
+{
+  struct file_name_map_list *map_list_next;
+  char *map_list_name;
+  struct file_name_map *map_list_map;
+};
+
+/* Read the file name map file for DIRNAME.  */
+
+static struct file_name_map *
+read_name_map (pfile, dirname)
+     cpp_reader *pfile;
+     const char *dirname;
+{
+  register struct file_name_map_list *map_list_ptr;
+  char *name;
+  FILE *f;
+
+  for (map_list_ptr = CPP_OPTIONS (pfile)->map_list; map_list_ptr;
+       map_list_ptr = map_list_ptr->map_list_next)
+    if (! strcmp (map_list_ptr->map_list_name, dirname))
+      return map_list_ptr->map_list_map;
+
+  map_list_ptr = ((struct file_name_map_list *)
+		  xmalloc (sizeof (struct file_name_map_list)));
+  map_list_ptr->map_list_name = xstrdup (dirname);
+
+  name = (char *) alloca (strlen (dirname) + strlen (FILE_NAME_MAP_FILE) + 2);
+  strcpy (name, dirname);
+  if (*dirname)
+    strcat (name, "/");
+  strcat (name, FILE_NAME_MAP_FILE);
+  f = fopen (name, "r");
+  if (!f)
+    map_list_ptr->map_list_map = (struct file_name_map *)-1;
+  else
+    {
+      int ch;
+      int dirlen = strlen (dirname);
+
+      while ((ch = getc (f)) != EOF)
+	{
+	  char *from, *to;
+	  struct file_name_map *ptr;
+
+	  if (is_space[ch])
+	    continue;
+	  from = read_filename_string (ch, f);
+	  while ((ch = getc (f)) != EOF && is_hor_space[ch])
+	    ;
+	  to = read_filename_string (ch, f);
+
+	  ptr = ((struct file_name_map *)
+		 xmalloc (sizeof (struct file_name_map)));
+	  ptr->map_from = from;
+
+	  /* Make the real filename absolute.  */
+	  if (*to == '/')
+	    ptr->map_to = to;
+	  else
+	    {
+	      ptr->map_to = xmalloc (dirlen + strlen (to) + 2);
+	      strcpy (ptr->map_to, dirname);
+	      ptr->map_to[dirlen] = '/';
+	      strcpy (ptr->map_to + dirlen + 1, to);
+	      free (to);
+	    }	      
+
+	  ptr->map_next = map_list_ptr->map_list_map;
+	  map_list_ptr->map_list_map = ptr;
+
+	  while ((ch = getc (f)) != '\n')
+	    if (ch == EOF)
+	      break;
+	}
+      fclose (f);
+    }
+  
+  map_list_ptr->map_list_next = CPP_OPTIONS (pfile)->map_list;
+  CPP_OPTIONS (pfile)->map_list = map_list_ptr;
+
+  return map_list_ptr->map_list_map;
+}  
+
+/* Remap NAME based on the file_name_map (if any) for LOC. */
+
+static char *
+remap_filename (pfile, name, loc)
+     cpp_reader *pfile;
+     char *name;
+     struct file_name_list *loc;
+{
+  struct file_name_map *map;
+  const char *from, *p, *dir;
+
+  if (! loc->name_map)
+    loc->name_map = read_name_map (pfile,
+				   loc->name
+				   ? loc->name : ".");
+
+  if (loc->name_map == (struct file_name_map *)-1)
+    return name;
+  
+  from = name + strlen (loc->name) + 1;
+  
+  for (map = loc->name_map; map; map = map->map_next)
+    if (!strcmp (map->map_from, from))
+      return map->map_to;
+
+  /* Try to find a mapping file for the particular directory we are
+     looking in.  Thus #include <sys/types.h> will look up sys/types.h
+     in /usr/include/header.gcc and look up types.h in
+     /usr/include/sys/header.gcc.  */
+  p = rindex (name, '/');
+  if (!p)
+    p = name;
+  if (loc && loc->name
+      && strlen (loc->name) == (size_t) (p - name)
+      && !strncmp (loc->name, name, p - name))
+    /* FILENAME is in SEARCHPTR, which we've already checked.  */
+    return name;
+
+  if (p == name)
+    {
+      dir = ".";
+      from = name;
+    }
+  else
+    {
+      char * newdir = (char *) alloca (p - name + 1);
+      bcopy (name, newdir, p - name);
+      newdir[p - name] = '\0';
+      dir = newdir;
+      from = p + 1;
+    }
+  
+  for (map = read_name_map (pfile, dir); map; map = map->map_next)
+    if (! strcmp (map->map_from, name))
+      return map->map_to;
+
+  return name;
+}
+
+/* Read the contents of FD into the buffer on the top of PFILE's stack.
+   IHASH points to the include hash entry for the file associated with
+   FD.
+
+   The caller is responsible for the cpp_push_buffer.  */
+
+int
+finclude (pfile, fd, ihash)
+     cpp_reader *pfile;
+     int fd;
+     struct include_hash *ihash;
+{
+  struct stat st;
+  size_t st_size;
+  long length;
+  cpp_buffer *fp;
+
+  if (fstat (fd, &st) < 0)
+    goto perror_fail;
+  if (fcntl (fd, F_SETFL, 0) == -1)  /* turn off nonblocking mode */
+    goto perror_fail;
+
+  fp = CPP_BUFFER (pfile);
+
+  /* If fd points to a plain file, we know how big it is, so we can
+     allocate the buffer all at once.  If fd is a pipe or terminal, we
+     can't.  Most C source files are 4k or less, so we guess that.  If
+     fd is something weird, like a block device or a directory, we
+     don't want to read it at all.
+
+     Unfortunately, different systems use different st.st_mode values
+     for pipes: some have S_ISFIFO, some S_ISSOCK, some are buggy and
+     zero the entire struct stat except a couple fields.  Hence the
+     mess below.
+
+     In all cases, read_and_prescan will resize the buffer if it
+     turns out there's more data than we thought.  */
+
+  if (S_ISREG (st.st_mode))
+    {
+      /* off_t might have a wider range than size_t - in other words,
+	 the max size of a file might be bigger than the address
+	 space.  We can't handle a file that large.  (Anyone with
+         a single source file bigger than 4GB needs to rethink
+	 their coding style.)  */
+      st_size = (size_t) st.st_size;
+      if ((unsigned HOST_WIDEST_INT) st_size
+	  != (unsigned HOST_WIDEST_INT) st.st_size)
+	{
+	  cpp_error (pfile, "file `%s' is too large", ihash->name);
+	  goto fail;
+	}
+    }
+  else if (S_ISFIFO (st.st_mode) || S_ISSOCK (st.st_mode)
+	   /* Permit any kind of character device: the sensible ones are
+	      ttys and /dev/null, but weeding out the others is too hard.  */
+	   || S_ISCHR (st.st_mode)
+	   /* Some 4.x (x<4) derivatives have a bug that makes fstat() of a
+	      socket or pipe return a stat struct with most fields zeroed.  */
+	   || (st.st_mode == 0 && st.st_nlink == 0 && st.st_size == 0))
+    {
+      /* Cannot get its file size before reading.  4k is a decent
+         first guess. */
+      st_size = 4096;
+    }
+  else
+    {
+      cpp_error (pfile, "`%s' is not a file, pipe, or tty", ihash->name);
+      goto fail;
+    }
+
+  if (pfile->input_buffer == NULL)
+    initialize_input_buffer (pfile, fd, &st);
+
+  /* Read the file, converting end-of-line characters and trigraphs
+     (if enabled). */
+  fp->ihash = ihash;
+  fp->nominal_fname = fp->fname = ihash->name;
+  length = read_and_prescan (pfile, fp, fd, st_size);
+  if (length < 0)
+    goto fail;
+  if (length == 0)
+    ihash->control_macro = "";  /* never re-include */
+
+  close (fd);
+  fp->rlimit = fp->alimit = fp->buf + length;
+  fp->cur = fp->buf;
+  if (ihash->foundhere != ABSOLUTE_PATH)
+      fp->system_header_p = ihash->foundhere->sysp;
+  fp->lineno = 1;
+  fp->colno = 1;
+  fp->line_base = fp->buf;
+  fp->cleanup = file_cleanup;
+
+  /* The ->actual_dir field is only used when ignore_srcdir is not in effect;
+     see do_include */
+  if (!CPP_OPTIONS (pfile)->ignore_srcdir)
+    fp->actual_dir = actual_directory (pfile, fp->fname);
+
+  pfile->input_stack_listing_current = 0;
+  return 1;
+
+ perror_fail:
+  cpp_error_from_errno (pfile, ihash->name);
+ fail:
+  cpp_pop_buffer (pfile);
+  close (fd);
+  return 0;
+}
+
+/* Given a path FNAME, extract the directory component and place it
+   onto the actual_dirs list.  Return a pointer to the allocated
+   file_name_list structure.  These structures are used to implement
+   current-directory "" include searching. */
+
+static struct file_name_list *
+actual_directory (pfile, fname)
+     cpp_reader *pfile;
+     char *fname;
+{
+  char *last_slash, *dir;
+  size_t dlen;
+  struct file_name_list *x;
+  
+  dir = xstrdup (fname);
+  last_slash = rindex (dir, '/');
+  if (last_slash)
+    {
+      if (last_slash == dir)
+        {
+	  dlen = 1;
+	  last_slash[1] = '\0';
+	}
+      else
+	{
+	  dlen = last_slash - dir;
+	  *last_slash = '\0';
+	}
+    }
+  else
+    {
+      dir[0] = '.';
+      dir[1] = '\0';
+      dlen = 1;
+    }
+
+  if (dlen > pfile->max_include_len)
+    pfile->max_include_len = dlen;
+
+  for (x = pfile->actual_dirs; x; x = x->alloc)
+    if (!strcmp (x->name, dir))
+      {
+	free (dir);
+	return x;
+      }
+
+  /* Not found, make a new one. */
+  x = (struct file_name_list *) xmalloc (sizeof (struct file_name_list));
+  x->name = dir;
+  x->nlen = dlen;
+  x->next = CPP_OPTIONS (pfile)->quote_include;
+  x->alloc = pfile->actual_dirs;
+  x->sysp = CPP_BUFFER (pfile)->system_header_p;
+  x->name_map = NULL;
+
+  pfile->actual_dirs = x;
+  return x;
+}
+
+/* Determine the current line and column.  Used only by read_and_prescan. */
+static void
+find_position (start, limit, linep, colp)
+     U_CHAR *start;
+     U_CHAR *limit;
+     unsigned long *linep;
+     unsigned long *colp;
+{
+  unsigned long line = *linep, col = 0;
+  while (start < limit)
+    {
+      U_CHAR ch = *start++;
+      if (ch == '\n' || ch == '\r')
+	line++, col = 1;
+      else
+	col++;
+    }
+  *linep = line, *colp = col;
+}
+
+/* Read the entire contents of file DESC into buffer BUF.  LEN is how
+   much memory to allocate initially; more will be allocated if
+   necessary.  Convert end-of-line markers (\n, \r, \r\n, \n\r) to
+   canonical form (\n).  If enabled, convert and/or warn about
+   trigraphs.  Convert backslash-newline to a one-character escape
+   (\r) and remove it from "embarrassing" places (i.e. the middle of a
+   token).  If there is no newline at the end of the file, add one and
+   warn.  Returns -1 on failure, or the actual length of the data to
+   be scanned.
+
+   This function does a lot of work, and can be a serious performance
+   bottleneck.  It has been tuned heavily; make sure you understand it
+   before hacking.  The common case - no trigraphs, Unix style line
+   breaks, backslash-newline set off by whitespace, newline at EOF -
+   has been optimized at the expense of the others.  The performance
+   penalty for DOS style line breaks (\r\n) is about 15%.
+   
+   Warnings lose particularly heavily since we have to determine the
+   line number, which involves scanning from the beginning of the file
+   or from the last warning.  The penalty for the absence of a newline
+   at the end of reload1.c is about 60%.  (reload1.c is 329k.)
+
+   If your file has more than one kind of end-of-line marker, you
+   will get messed-up line numbering.  */
+
+/* Table of characters that can't be handled in the inner loop.
+   Keep these contiguous to optimize the performance of the code generated
+   for the switch that uses them.  */
+#define SPECCASE_EMPTY     0
+#define SPECCASE_NUL       1
+#define SPECCASE_CR        2
+#define SPECCASE_BACKSLASH 3
+#define SPECCASE_QUESTION  4
+
+static long
+read_and_prescan (pfile, fp, desc, len)
+     cpp_reader *pfile;
+     cpp_buffer *fp;
+     int desc;
+     size_t len;
+{
+  U_CHAR *buf = (U_CHAR *) xmalloc (len);
+  U_CHAR *ip, *op, *line_base;
+  U_CHAR *ibase;
+  U_CHAR *speccase = pfile->input_speccase;
+  unsigned long line;
+  unsigned int deferred_newlines;
+  int count;
+  size_t offset;
+
+  offset = 0;
+  op = buf;
+  line_base = buf;
+  line = 1;
+  ibase = pfile->input_buffer + 2;
+  deferred_newlines = 0;
+
+  for (;;)
+    {
+    read_next:
+
+      count = read (desc, pfile->input_buffer + 2, pfile->input_buffer_len);
+      if (count < 0)
+	goto error;
+      else if (count == 0)
+	break;
+
+      offset += count;
+      ip = ibase;
+      ibase = pfile->input_buffer + 2;
+      ibase[count] = ibase[count+1] = '\0';
+
+      if (offset > len)
+	{
+	  size_t delta_op;
+	  size_t delta_line_base;
+	  len *= 2;
+	  if (offset > len)
+	    /* len overflowed.
+	       This could happen if the file is larger than half the
+	       maximum address space of the machine. */
+	    goto too_big;
+
+	  delta_op = op - buf;
+	  delta_line_base = line_base - buf;
+	  buf = (U_CHAR *) xrealloc (buf, len);
+	  op = buf + delta_op;
+	  line_base = buf + delta_line_base;
+	}
+
+      for (;;)
+	{
+	  unsigned int span = 0;
+
+	  /* Deal with \-newline in the middle of a token. */
+	  if (deferred_newlines)
+	    {
+	      while (speccase[ip[span]] == SPECCASE_EMPTY
+		     && ip[span] != '\n'
+		     && ip[span] != '\t'
+		     && ip[span] != ' ')
+		span++;
+	      memcpy (op, ip, span);
+	      op += span;
+	      ip += span;
+	      if (*ip == '\n' || *ip == '\t'
+		  || *ip == ' ' || *ip == ' ')
+		while (deferred_newlines)
+		  deferred_newlines--, *op++ = '\r';
+	      span = 0;
+	    }
+
+	  /* Copy as much as we can without special treatment. */
+	  while (speccase[ip[span]] == SPECCASE_EMPTY) span++;
+	  memcpy (op, ip, span);
+	  op += span;
+	  ip += span;
+
+	  switch (speccase[*ip++])
+	    {
+	    case SPECCASE_NUL:  /* \0 */
+	      ibase[-1] = op[-1];
+	      goto read_next;
+
+	    case SPECCASE_CR:  /* \r */
+	      if (*ip == '\n')
+		ip++;
+	      else if (*ip == '\0')
+		{
+		  *--ibase = '\r';
+		  goto read_next;
+		}
+	      else if (ip[-2] == '\n')
+		continue;
+	      *op++ = '\n';
+	      break;
+
+	    case SPECCASE_BACKSLASH:  /* \ */
+	    backslash:
+	    {
+	      /* If we're at the end of the intermediate buffer,
+		 we have to shift the backslash down to the start
+		 and come back next pass. */
+	      if (*ip == '\0')
+		{
+		  *--ibase = '\\';
+		  goto read_next;
+		}
+	      else if (*ip == '\n')
+		{
+		  ip++;
+		  if (*ip == '\r') ip++;
+		  if (*ip == '\n' || *ip == '\t' || *ip == ' ')
+		    *op++ = '\r';
+		  else if (op[-1] == '\t' || op[-1] == ' '
+			   || op[-1] == '\r' || op[-1] == '\n')
+		    *op++ = '\r';
+		  else
+		    deferred_newlines++;
+		  line++;
+		  line_base = op;
+		}
+	      else if (*ip == '\r')
+		{
+		  ip++;
+		  if (*ip == '\n') ip++;
+		  else if (*ip == '\0')
+		    {
+		      *--ibase = '\r';
+		      *--ibase = '\\';
+		      goto read_next;
+		    }
+		  else if (*ip == '\r' || *ip == '\t' || *ip == ' ')
+		    *op++ = '\r';
+		  else
+		    deferred_newlines++;
+		  line++;
+		  line_base = op;
+		}
+	      else
+		*op++ = '\\';
+	    }
+	    break;
+
+	    case SPECCASE_QUESTION: /* ? */
+	      {
+		unsigned int d;
+		/* If we're at the end of the intermediate buffer,
+		   we have to shift the ?'s down to the start and
+		   come back next pass. */
+		d = ip[0];
+		if (d == '\0')
+		  {
+		    *--ibase = '?';
+		    goto read_next;
+		  }
+		if (d != '?')
+		  {
+		    *op++ = '?';
+		    break;
+		  }
+		d = ip[1];
+		if (d == '\0')
+		  {
+		    *--ibase = '?';
+		    *--ibase = '?';
+		    goto read_next;
+		  }
+		if (!trigraph_table[d])
+		  {
+		    *op++ = '?';
+		    break;
+		  }
+
+		if (CPP_OPTIONS (pfile)->warn_trigraphs)
+		  {
+		    unsigned long col;
+		    find_position (line_base, op, &line, &col);
+		    line_base = op - col;
+		    cpp_warning_with_line (pfile, line, col,
+					   "trigraph ??%c encountered", d);
+		  }
+		if (CPP_OPTIONS (pfile)->trigraphs)
+		  {
+		    if (trigraph_table[d] == '\\')
+		      goto backslash;
+		    else
+		      *op++ = trigraph_table[d];
+		  }
+		else
+		  {
+		    *op++ = '?';
+		    *op++ = '?';
+		    *op++ = d;
+		  }
+		ip += 2;
+	      }
+	    }
+	}
+    }
+
+  if (offset == 0)
+    return 0;
+
+  /* Deal with pushed-back chars at true EOF.
+     This may be any of:  ?? ? \ \r \n \\r \\n.
+     \r must become \n, \\r or \\n must become \r.
+     We know we have space already. */
+  if (ibase == pfile->input_buffer)
+    {
+      if (*ibase == '?')
+	{
+	  *op++ = '?';
+	  *op++ = '?';
+	}
+      else
+	*op++ = '\r';
+    }
+  else if (ibase == pfile->input_buffer + 1)
+    {
+      if (*ibase == '\r')
+	*op++ = '\n';
+      else
+	*op++ = *ibase;
+    }
+
+  if (op[-1] != '\n')
+    {
+      unsigned long col;
+      find_position (line_base, op, &line, &col);
+      cpp_warning_with_line (pfile, line, col, "no newline at end of file\n");
+      if (offset + 1 > len)
+	{
+	  len += 1;
+	  if (offset + 1 > len)
+	    goto too_big;
+	  buf = (U_CHAR *) xrealloc (buf, len);
+	  op = buf + offset;
+	}
+      *op++ = '\n';
+    }
+
+  fp->buf = ((len - offset < 20) ? buf : (U_CHAR *)xrealloc (buf, op - buf));
+  return op - buf;
+
+ too_big:
+  cpp_error (pfile, "file is too large (>%lu bytes)\n", (unsigned long)offset);
+  free (buf);
+  return -1;
+
+ error:
+  cpp_error_from_errno (pfile, fp->fname);
+  free (buf);
+  return -1;
+}
+
+/* Initialize the `input_buffer' and `input_speccase' tables.
+   These are only used by read_and_prescan, but they're large and
+   somewhat expensive to set up, so we want them allocated once for
+   the duration of the cpp run.  */
+
+static void
+initialize_input_buffer (pfile, fd, st)
+     cpp_reader *pfile;
+     int fd;
+     struct stat *st;
+{
+  long pipe_buf;
+  U_CHAR *tmp;
+
+  /* Table of characters that cannot be handled by the
+     read_and_prescan inner loop.  The number of non-EMPTY entries
+     should be as small as humanly possible.  */
+
+  tmp = xmalloc (1 << CHAR_BIT);
+  memset (tmp, SPECCASE_EMPTY, 1 << CHAR_BIT);
+  tmp['\0'] = SPECCASE_NUL;
+  tmp['\r'] = SPECCASE_CR;
+  tmp['\\'] = SPECCASE_BACKSLASH;
+  if (CPP_OPTIONS (pfile)->trigraphs || CPP_OPTIONS (pfile)->warn_trigraphs)
+    tmp['?'] = SPECCASE_QUESTION;
+
+  pfile->input_speccase = tmp;
+
+  /* Determine the appropriate size for the input buffer.  Normal C
+     source files are smaller than eight K.  If we are reading a pipe,
+     we want to make sure the input buffer is bigger than the kernel's
+     pipe buffer.  */
+  pipe_buf = -1;
+
+  if (! S_ISREG (st->st_mode))
+    {
+#ifdef _PC_PIPE_BUF
+      pipe_buf = fpathconf (fd, _PC_PIPE_BUF);
+#endif
+      if (pipe_buf == -1)
+	{
+#ifdef PIPE_BUF
+	  pipe_buf = PIPE_BUF;
+#else
+	  pipe_buf = 8192;
+#endif
+	}
+    }
+
+  if (pipe_buf < 8192)
+    pipe_buf = 8192;
+  /* PIPE_BUF bytes of buffer proper, 2 to detect running off the end
+     without address arithmetic all the time, and 2 for pushback in
+     the case there's a potential trigraph or end-of-line digraph at
+     the end of a block. */
+
+  tmp = xmalloc (pipe_buf + 2 + 2);
+  pfile->input_buffer = tmp;
+  pfile->input_buffer_len = pipe_buf;
+}
+
+/* Add output to `deps_buffer' for the -M switch.
+   STRING points to the text to be output.
+   SPACER is ':' for targets, ' ' for dependencies, zero for text
+   to be inserted literally.  */
+
+void
+deps_output (pfile, string, spacer)
+     cpp_reader *pfile;
+     char *string;
+     int spacer;
+{
+  int size;
+  int cr = 0;
+
+  if (!*string)
+    return;
+
+  size = strlen (string);
+
+#ifndef MAX_OUTPUT_COLUMNS
+#define MAX_OUTPUT_COLUMNS 72
+#endif
+  if (pfile->deps_column > 0
+      && (pfile->deps_column + size) > MAX_OUTPUT_COLUMNS)
+    {
+      cr = 5;
+      pfile->deps_column = 0;
+    }
+
+  if (pfile->deps_size + size + cr + 8 > pfile->deps_allocated_size)
+    {
+      pfile->deps_allocated_size = (pfile->deps_size + size + 50) * 2;
+      pfile->deps_buffer = (char *) xrealloc (pfile->deps_buffer,
+					      pfile->deps_allocated_size);
+    }
+
+  if (cr)
+    {
+      bcopy (" \\\n  ", &pfile->deps_buffer[pfile->deps_size], 5);
+      pfile->deps_size += 5;
+    }
+  
+  if (spacer == ' ' && pfile->deps_column > 0)
+    pfile->deps_buffer[pfile->deps_size++] = ' ';
+  bcopy (string, &pfile->deps_buffer[pfile->deps_size], size);
+  pfile->deps_size += size;
+  pfile->deps_column += size;
+  if (spacer == ':')
+    pfile->deps_buffer[pfile->deps_size++] = ':';
+  pfile->deps_buffer[pfile->deps_size] = 0;
+}
+
+/* Simplify a path name in place, deleting redundant components.  This
+   reduces OS overhead and guarantees that equivalent paths compare
+   the same (modulo symlinks).
+
+   Transforms made:
+   foo/bar/../quux	foo/quux
+   foo/./bar		foo/bar
+   foo//bar		foo/bar
+   /../quux		/quux
+   //quux		//quux  (POSIX allows leading // as a namespace escape)
+
+   Guarantees no trailing slashes. All transforms reduce the length
+   of the string.
+ */
+void
+simplify_pathname (path)
+    char *path;
+{
+    char *from, *to;
+    char *base;
+    int absolute = 0;
+
+#if defined (HAVE_DOS_BASED_FILE_SYSTEM)
+    /* Convert all backslashes to slashes. */
+    for (from = path; *from; from++)
+	if (*from == '\\') *from = '/';
+    
+    /* Skip over leading drive letter if present. */
+    if (ISALPHA (path[0]) && path[1] == ':')
+	from = to = &path[2];
+    else
+	from = to = path;
+#else
+    from = to = path;
+#endif
+    
+    /* Remove redundant initial /s.  */
+    if (*from == '/')
+    {
+	absolute = 1;
+	to++;
+	from++;
+	if (*from == '/')
+	{
+	    if (*++from == '/')
+		/* 3 or more initial /s are equivalent to 1 /.  */
+		while (*++from == '/');
+	    else
+		/* On some hosts // differs from /; Posix allows this.  */
+		to++;
+	}
+    }
+    base = to;
+    
+    for (;;)
+    {
+	while (*from == '/')
+	    from++;
+
+	if (from[0] == '.' && from[1] == '/')
+	    from += 2;
+	else if (from[0] == '.' && from[1] == '\0')
+	    goto done;
+	else if (from[0] == '.' && from[1] == '.' && from[2] == '/')
+	{
+	    if (base == to)
+	    {
+		if (absolute)
+		    from += 3;
+		else
+		{
+		    *to++ = *from++;
+		    *to++ = *from++;
+		    *to++ = *from++;
+		    base = to;
+		}
+	    }
+	    else
+	    {
+		to -= 2;
+		while (to > base && *to != '/') to--;
+		if (*to == '/')
+		    to++;
+		from += 3;
+	    }
+	}
+	else if (from[0] == '.' && from[1] == '.' && from[2] == '\0')
+	{
+	    if (base == to)
+	    {
+		if (!absolute)
+		{
+		    *to++ = *from++;
+		    *to++ = *from++;
+		}
+	    }
+	    else
+	    {
+		to -= 2;
+		while (to > base && *to != '/') to--;
+		if (*to == '/')
+		    to++;
+	    }
+	    goto done;
+	}
+	else
+	    /* Copy this component and trailing /, if any.  */
+	    while ((*to++ = *from++) != '/')
+	    {
+		if (!to[-1])
+		{
+		    to--;
+		    goto done;
+		}
+	    }
+	
+    }
+    
+ done:
+    /* Trim trailing slash */
+    if (to[0] == '/' && (!absolute || to > path+1))
+	to--;
+
+    /* Change the empty string to "." so that stat() on the result
+       will always work. */
+    if (to == path)
+      *to++ = '.';
+    
+    *to = '\0';
+
+    return;
+}
+
+/* It is not clear when this should be used if at all, so I've
+   disabled it until someone who understands VMS can look at it. */
+#if 0
+
+/* Under VMS we need to fix up the "include" specification filename.
+
+   Rules for possible conversions
+
+	fullname		tried paths
+
+	name			name
+	./dir/name		[.dir]name
+	/dir/name		dir:name
+	/name			[000000]name, name
+	dir/name		dir:[000000]name, dir:name, dir/name
+	dir1/dir2/name		dir1:[dir2]name, dir1:[000000.dir2]name
+	path:/name		path:[000000]name, path:name
+	path:/dir/name		path:[000000.dir]name, path:[dir]name
+	path:dir/name		path:[dir]name
+	[path]:[dir]name	[path.dir]name
+	path/[dir]name		[path.dir]name
+
+   The path:/name input is constructed when expanding <> includes. */
+
+
+static void
+hack_vms_include_specification (fullname)
+     char *fullname;
+{
+  register char *basename, *unixname, *local_ptr, *first_slash;
+  int f, check_filename_before_returning, must_revert;
+  char Local[512];
+
+  check_filename_before_returning = 0;
+  must_revert = 0;
+  /* See if we can find a 1st slash. If not, there's no path information.  */
+  first_slash = index (fullname, '/');
+  if (first_slash == 0)
+    return 0;				/* Nothing to do!!! */
+
+  /* construct device spec if none given.  */
+
+  if (index (fullname, ':') == 0)
+    {
+
+      /* If fullname has a slash, take it as device spec.  */
+
+      if (first_slash == fullname)
+	{
+	  first_slash = index (fullname+1, '/');	/* 2nd slash ? */
+	  if (first_slash)
+	    *first_slash = ':';				/* make device spec  */
+	  for (basename = fullname; *basename != 0; basename++)
+	    *basename = *(basename+1);			/* remove leading slash  */
+	}
+      else if ((first_slash[-1] != '.')		/* keep ':/', './' */
+	    && (first_slash[-1] != ':')
+	    && (first_slash[-1] != ']'))	/* or a vms path  */
+	{
+	  *first_slash = ':';
+	}
+      else if ((first_slash[1] == '[')		/* skip './' in './[dir'  */
+	    && (first_slash[-1] == '.'))
+	fullname += 2;
+    }
+
+  /* Get part after first ':' (basename[-1] == ':')
+     or last '/' (basename[-1] == '/').  */
+
+  basename = base_name (fullname);
+
+  local_ptr = Local;			/* initialize */
+
+  /* We are trying to do a number of things here.  First of all, we are
+     trying to hammer the filenames into a standard format, such that later
+     processing can handle them.
+     
+     If the file name contains something like [dir.], then it recognizes this
+     as a root, and strips the ".]".  Later processing will add whatever is
+     needed to get things working properly.
+     
+     If no device is specified, then the first directory name is taken to be
+     a device name (or a rooted logical).  */
+
+  /* Point to the UNIX filename part (which needs to be fixed!)
+     but skip vms path information.
+     [basename != fullname since first_slash != 0].  */
+
+  if ((basename[-1] == ':')		/* vms path spec.  */
+      || (basename[-1] == ']')
+      || (basename[-1] == '>'))
+    unixname = basename;
+  else
+    unixname = fullname;
+
+  if (*unixname == '/')
+    unixname++;
+
+  /* If the directory spec is not rooted, we can just copy
+     the UNIX filename part and we are done.  */
+
+  if (((basename - fullname) > 1)
+     && (  (basename[-1] == ']')
+        || (basename[-1] == '>')))
+    {
+      if (basename[-2] != '.')
+	{
+
+	/* The VMS part ends in a `]', and the preceding character is not a `.'.
+	   -> PATH]:/name (basename = '/name', unixname = 'name')
+	   We strip the `]', and then splice the two parts of the name in the
+	   usual way.  Given the default locations for include files in cccp.c,
+	   we will only use this code if the user specifies alternate locations
+	   with the /include (-I) switch on the command line.  */
+
+	  basename -= 1;	/* Strip "]" */
+	  unixname--;		/* backspace */
+	}
+      else
+	{
+
+	/* The VMS part has a ".]" at the end, and this will not do.  Later
+	   processing will add a second directory spec, and this would be a syntax
+	   error.  Thus we strip the ".]", and thus merge the directory specs.
+	   We also backspace unixname, so that it points to a '/'.  This inhibits the
+	   generation of the 000000 root directory spec (which does not belong here
+	   in this case).  */
+
+	  basename -= 2;	/* Strip ".]" */
+	  unixname--;		/* backspace */
+	}
+    }
+
+  else
+
+    {
+
+      /* We drop in here if there is no VMS style directory specification yet.
+         If there is no device specification either, we make the first dir a
+         device and try that.  If we do not do this, then we will be essentially
+         searching the users default directory (as if they did a #include "asdf.h").
+        
+         Then all we need to do is to push a '[' into the output string. Later
+         processing will fill this in, and close the bracket.  */
+
+      if ((unixname != fullname)	/* vms path spec found.  */
+	 && (basename[-1] != ':'))
+	*local_ptr++ = ':';		/* dev not in spec.  take first dir */
+
+      *local_ptr++ = '[';		/* Open the directory specification */
+    }
+
+    if (unixname == fullname)		/* no vms dir spec.  */
+      {
+	must_revert = 1;
+	if ((first_slash != 0)		/* unix dir spec.  */
+	    && (*unixname != '/')	/* not beginning with '/'  */
+	    && (*unixname != '.'))	/* or './' or '../'  */
+	  *local_ptr++ = '.';		/* dir is local !  */
+      }
+
+  /* at this point we assume that we have the device spec, and (at least
+     the opening "[" for a directory specification.  We may have directories
+     specified already.
+
+     If there are no other slashes then the filename will be
+     in the "root" directory.  Otherwise, we need to add
+     directory specifications.  */
+
+  if (index (unixname, '/') == 0)
+    {
+      /* if no directories specified yet and none are following.  */
+      if (local_ptr[-1] == '[')
+	{
+	  /* Just add "000000]" as the directory string */
+	  strcpy (local_ptr, "000000]");
+	  local_ptr += strlen (local_ptr);
+	  check_filename_before_returning = 1; /* we might need to fool with this later */
+	}
+    }
+  else
+    {
+
+      /* As long as there are still subdirectories to add, do them.  */
+      while (index (unixname, '/') != 0)
+	{
+	  /* If this token is "." we can ignore it
+	       if it's not at the beginning of a path.  */
+	  if ((unixname[0] == '.') && (unixname[1] == '/'))
+	    {
+	      /* remove it at beginning of path.  */
+	      if (  ((unixname == fullname)		/* no device spec  */
+		    && (fullname+2 != basename))	/* starts with ./ */
+							/* or  */
+		 || ((basename[-1] == ':')		/* device spec  */
+		    && (unixname-1 == basename)))	/* and ./ afterwards  */
+		*local_ptr++ = '.';		 	/* make '[.' start of path.  */
+	      unixname += 2;
+	      continue;
+	    }
+
+	  /* Add a subdirectory spec. Do not duplicate "." */
+	  if (  local_ptr[-1] != '.'
+	     && local_ptr[-1] != '['
+	     && local_ptr[-1] != '<')
+	    *local_ptr++ = '.';
+
+	  /* If this is ".." then the spec becomes "-" */
+	  if (  (unixname[0] == '.')
+	     && (unixname[1] == '.')
+	     && (unixname[2] == '/'))
+	    {
+	      /* Add "-" and skip the ".." */
+	      if ((local_ptr[-1] == '.')
+		  && (local_ptr[-2] == '['))
+		local_ptr--;			/* prevent [.-  */
+	      *local_ptr++ = '-';
+	      unixname += 3;
+	      continue;
+	    }
+
+	  /* Copy the subdirectory */
+	  while (*unixname != '/')
+	    *local_ptr++= *unixname++;
+
+	  unixname++;			/* Skip the "/" */
+	}
+
+      /* Close the directory specification */
+      if (local_ptr[-1] == '.')		/* no trailing periods */
+	local_ptr--;
+
+      if (local_ptr[-1] == '[')		/* no dir needed */
+	local_ptr--;
+      else
+	*local_ptr++ = ']';
+    }
+
+  /* Now add the filename.  */
+
+  while (*unixname)
+    *local_ptr++ = *unixname++;
+  *local_ptr = 0;
+
+  /* Now append it to the original VMS spec.  */
+
+  strcpy ((must_revert==1)?fullname:basename, Local);
+
+  /* If we put a [000000] in the filename, try to open it first. If this fails,
+     remove the [000000], and return that name.  This provides flexibility
+     to the user in that they can use both rooted and non-rooted logical names
+     to point to the location of the file.  */
+
+  if (check_filename_before_returning)
+    {
+      f = open (fullname, O_RDONLY, 0666);
+      if (f >= 0)
+	{
+	  /* The file name is OK as it is, so return it as is.  */
+	  close (f);
+	  return 1;
+	}
+
+      /* The filename did not work.  Try to remove the [000000] from the name,
+	 and return it.  */
+
+      basename = index (fullname, '[');
+      local_ptr = index (fullname, ']') + 1;
+      strcpy (basename, local_ptr);		/* this gets rid of it */
+
+    }
+
+  return 1;
+}
+#endif	/* VMS */