dir.c

DSP网络驱动开发_TMS3206

/* Directory hashing for GNU Make.
Copyright (C) 1988,89,91,92,93,94,95,96,97 Free Software Foundation, Inc.
This file is part of GNU Make.

GNU Make 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.

GNU Make 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 GNU Make; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "make.h"

#ifdef	HAVE_DIRENT_H
# include <dirent.h>
# define NAMLEN(dirent) strlen((dirent)->d_name)
#else
# define dirent direct
# define NAMLEN(dirent) (dirent)->d_namlen
# ifdef HAVE_SYS_NDIR_H
#  include <sys/ndir.h>
# endif
# ifdef HAVE_SYS_DIR_H
#  include <sys/dir.h>
# endif
# ifdef HAVE_NDIR_H
#  include <ndir.h>
# endif
# ifdef HAVE_VMSDIR_H
#  include "vmsdir.h"
# endif /* HAVE_VMSDIR_H */
#endif

/* In GNU systems, <dirent.h> defines this macro for us.  */
#ifdef _D_NAMLEN
#undef NAMLEN
#define NAMLEN(d) _D_NAMLEN(d)
#endif

#if (defined (POSIX) || defined (WINDOWS32)) && !defined (__GNU_LIBRARY__)
/* Posix does not require that the d_ino field be present, and some
   systems do not provide it. */
#define REAL_DIR_ENTRY(dp) 1
#define FAKE_DIR_ENTRY(dp)
#else
#define REAL_DIR_ENTRY(dp) (dp->d_ino != 0)
#define FAKE_DIR_ENTRY(dp) (dp->d_ino = 1)
#endif /* POSIX */

#ifdef __MSDOS__
#include <ctype.h>
#include <fcntl.h>

/* If it's MSDOS that doesn't have _USE_LFN, disable LFN support.  */
#ifndef _USE_LFN
#define _USE_LFN 0
#endif

static char *
dosify (filename)
     char *filename;
{
  static char dos_filename[14];
  char *df;
  int i;

  if (filename == 0 || _USE_LFN)
    return filename;

  /* FIXME: what about filenames which violate
     8+3 constraints, like "config.h.in", or ".emacs"?  */
  if (strpbrk (filename, "\"*+,;<=>?[\\]|") != 0)
    return filename;

  df = dos_filename;

  /* First, transform the name part.  */
  for (i = 0; *filename != '\0' && i < 8 && *filename != '.'; ++i)
    *df++ = tolower (*filename++);

  /* Now skip to the next dot.  */
  while (*filename != '\0' && *filename != '.')
    ++filename;
  if (*filename != '\0')
    {
      *df++ = *filename++;
      for (i = 0; *filename != '\0' && i < 3 && *filename != '.'; ++i)
	*df++ = tolower (*filename++);
    }

  /* Look for more dots.  */
  while (*filename != '\0' && *filename != '.')
    ++filename;
  if (*filename == '.')
    return filename;
  *df = 0;
  return dos_filename;
}
#endif /* __MSDOS__ */

#ifdef WINDOWS32
#include "pathstuff.h"
#endif

#ifdef _AMIGA
#include <ctype.h>
#endif

#ifdef HAVE_CASE_INSENSITIVE_FS
static char *
downcase (filename)
     char *filename;
{
#ifdef _AMIGA
  static char new_filename[136];
#else
  static char new_filename[PATH_MAX];
#endif
  char *df;
  int i;

  if (filename == 0)
    return 0;

  df = new_filename;

  /* First, transform the name part.  */
  for (i = 0; *filename != '\0'; ++i)
  {
    *df++ = tolower (*filename);
    ++filename;
  }

  *df = 0;

  return new_filename;
}
#endif /* HAVE_CASE_INSENSITIVE_FS */

#ifdef VMS

static int
vms_hash (name)
    char *name;
{
  int h = 0;
  int g;

  while (*name)
    {
      h = (h << 4) + *name++;
      g = h & 0xf0000000;
      if (g)
	{
	  h = h ^ (g >> 24);
	  h = h ^ g;
	}
    }
  return h;
}

/* fake stat entry for a directory */
static int
vmsstat_dir (name, st)
    char *name;
    struct stat *st;
{
  char *s;
  int h;
  DIR *dir;

  dir = opendir (name);
  if (dir == 0)
    return -1;
  closedir (dir);
  s = strchr (name, ':');	/* find device */
  if (s)
    {
      *s++ = 0;
      st->st_dev = (char *)vms_hash (name);
      h = vms_hash (s);
      *(s-1) = ':';
    }
  else
    {
      st->st_dev = 0;
      s = name;
      h = vms_hash (s);
    }

  st->st_ino[0] = h & 0xff;
  st->st_ino[1] = h & 0xff00;
  st->st_ino[2] = h >> 16;

  return 0;
}
#endif /* VMS */

/* Hash table of directories.  */

#ifndef	DIRECTORY_BUCKETS
#define DIRECTORY_BUCKETS 199
#endif

struct directory_contents
  {
    struct directory_contents *next;

    dev_t dev;			/* Device and inode numbers of this dir.  */
#ifdef WINDOWS32
    /*
     * Inode means nothing on WINDOWS32. Even file key information is
     * unreliable because it is random per file open and undefined
     * for remote filesystems. The most unique attribute I can
     * come up with is the fully qualified name of the directory. Beware
     * though, this is also unreliable. I'm open to suggestion on a better
     * way to emulate inode.
     */
    char *path_key;
    int   mtime;        /* controls check for stale directory cache */
    int   fs_flags;     /* FS_FAT, FS_NTFS, ... */
#define FS_FAT      0x1
#define FS_NTFS     0x2
#define FS_UNKNOWN  0x4
#else
#ifdef VMS
    ino_t ino[3];
#else
    ino_t ino;
#endif
#endif /* WINDOWS32 */
    struct dirfile **files;	/* Files in this directory.  */
    DIR *dirstream;		/* Stream reading this directory.  */
  };

/* Table of directory contents hashed by device and inode number.  */
static struct directory_contents *directories_contents[DIRECTORY_BUCKETS];

struct directory
  {
    struct directory *next;

    char *name;			/* Name of the directory.  */

    /* The directory's contents.  This data may be shared by several
       entries in the hash table, which refer to the same directory
       (identified uniquely by `dev' and `ino') under different names.  */
    struct directory_contents *contents;
  };

/* Table of directories hashed by name.  */
static struct directory *directories[DIRECTORY_BUCKETS];


/* Never have more than this many directories open at once.  */

#define MAX_OPEN_DIRECTORIES 10

static unsigned int open_directories = 0;


/* Hash table of files in each directory.  */

struct dirfile
  {
    struct dirfile *next;
    char *name;			/* Name of the file.  */
    char impossible;		/* This file is impossible.  */
  };

#ifndef	DIRFILE_BUCKETS
#define DIRFILE_BUCKETS 107
#endif

static int dir_contents_file_exists_p PARAMS ((struct directory_contents *dir, char *filename));
static struct directory *find_directory PARAMS ((char *name));

/* Find the directory named NAME and return its `struct directory'.  */

static struct directory *
find_directory (name)
     register char *name;
{
  register unsigned int hash = 0;
  register char *p;
  register struct directory *dir;
#ifdef WINDOWS32
  char* w32_path;
  char  fs_label[BUFSIZ];
  char  fs_type[BUFSIZ];
  long  fs_serno;
  long  fs_flags;
  long  fs_len;
#endif
#ifdef VMS
  if ((*name == '.') && (*(name+1) == 0))
    name = "[]";
  else
    name = vmsify (name,1);
#endif

  for (p = name; *p != '\0'; ++p)
    HASHI (hash, *p);
  hash %= DIRECTORY_BUCKETS;

  for (dir = directories[hash]; dir != 0; dir = dir->next)
    if (strieq (dir->name, name))
      break;

  if (dir == 0)
    {
      struct stat st;

      /* The directory was not found.  Create a new entry for it.  */

      dir = (struct directory *) xmalloc (sizeof (struct directory));
      dir->next = directories[hash];
      directories[hash] = dir;
      dir->name = savestring (name, p - name);

      /* The directory is not in the name hash table.
	 Find its device and inode numbers, and look it up by them.  */

#ifdef VMS
      if (vmsstat_dir (name, &st) < 0)
#else

#ifdef WINDOWS32
      /* Remove any trailing '\'.  Windows32 stat fails even on valid
         directories if they end in '\'. */
      if (p[-1] == '\\')
        p[-1] = '\0';
#endif
      if (stat (name, &st) < 0)
#endif
	{
	/* Couldn't stat the directory.  Mark this by
	   setting the `contents' member to a nil pointer.  */
	  dir->contents = 0;
	}
      else
	{
	  /* Search the contents hash table; device and inode are the key.  */

	  struct directory_contents *dc;

#ifdef WINDOWS32
          w32_path = w32ify(name, 1);
          hash = ((unsigned int) st.st_dev << 16) | (unsigned int) st.st_ctime;
#else
#ifdef VMS
	hash = ((unsigned int) st.st_dev << 16)
		| ((unsigned int) st.st_ino[0]
		+ (unsigned int) st.st_ino[1]
		+ (unsigned int) st.st_ino[2]);
#else
	  hash = ((unsigned int) st.st_dev << 16) | (unsigned int) st.st_ino;
#endif
#endif
	  hash %= DIRECTORY_BUCKETS;

	  for (dc = directories_contents[hash]; dc != 0; dc = dc->next)
#ifdef WINDOWS32
            if (strieq(dc->path_key, w32_path))
#else
	    if (dc->dev == st.st_dev
#ifdef VMS
		&& dc->ino[0] == st.st_ino[0]
		&& dc->ino[1] == st.st_ino[1]
		&& dc->ino[2] == st.st_ino[2])
#else
		 && dc->ino == st.st_ino)
#endif
#endif /* WINDOWS32 */
	      break;

	  if (dc == 0)
	    {
	      /* Nope; this really is a directory we haven't seen before.  */

	      dc = (struct directory_contents *)
		xmalloc (sizeof (struct directory_contents));

	      /* Enter it in the contents hash table.  */
	      dc->dev = st.st_dev;
#ifdef WINDOWS32
              dc->path_key = xstrdup(w32_path);
              dc->mtime = st.st_mtime;

              /*
               * NTFS is the only WINDOWS32 filesystem that bumps mtime
               * on a directory when files are added/deleted from
               * a directory.
               */
              w32_path[3] = '\0';
              if (GetVolumeInformation(w32_path,
                     fs_label, sizeof (fs_label),
                     &fs_serno, &fs_len,
                     &fs_flags, fs_type, sizeof (fs_type)) == FALSE)
                dc->fs_flags = FS_UNKNOWN;
              else if (!strcmp(fs_type, "FAT"))
                dc->fs_flags = FS_FAT;
              else if (!strcmp(fs_type, "NTFS"))
                dc->fs_flags = FS_NTFS;
              else
                dc->fs_flags = FS_UNKNOWN;
#else
#ifdef VMS
	      dc->ino[0] = st.st_ino[0];
	      dc->ino[1] = st.st_ino[1];
	      dc->ino[2] = st.st_ino[2];
#else
	      dc->ino = st.st_ino;
#endif
#endif /* WINDOWS32 */
	      dc->next = directories_contents[hash];
	      directories_contents[hash] = dc;

	      dc->dirstream = opendir (name);
	      if (dc->dirstream == 0)
		{
		/* Couldn't open the directory.  Mark this by
		   setting the `files' member to a nil pointer.  */
		  dc->files = 0;
		}
	      else
		{
		  /* Allocate an array of buckets for files and zero it.  */
		  dc->files = (struct dirfile **)
		    xmalloc (sizeof (struct dirfile *) * DIRFILE_BUCKETS);
		  bzero ((char *) dc->files,
			 sizeof (struct dirfile *) * DIRFILE_BUCKETS);

		  /* Keep track of how many directories are open.  */
		  ++open_directories;
		  if (open_directories == MAX_OPEN_DIRECTORIES)
		    /* We have too many directories open already.
		       Read the entire directory and then close it.  */
		    (void) dir_contents_file_exists_p (dc, (char *) 0);
		}
	    }

	  /* Point the name-hashed entry for DIR at its contents data.  */
	  dir->contents = dc;
	}
    }

  return dir;
}

/* Return 1 if the name FILENAME is entered in DIR's hash table.
   FILENAME must contain no slashes.  */

static int
dir_contents_file_exists_p (dir, filename)
     register struct directory_contents *dir;
     register char *filename;
{
  register unsigned int hash;
  register char *p;
  register struct dirfile *df;
  register struct dirent *d;
#ifdef WINDOWS32
  struct stat st;
  int rehash = 0;
#endif

  if (dir == 0 || dir->files == 0)
    {
    /* The directory could not be stat'd or opened.  */
      return 0;
    }
#ifdef __MSDOS__
  filename = dosify (filename);
#endif

#ifdef HAVE_CASE_INSENSITIVE_FS
  filename = downcase (filename);
#endif

#ifdef VMS
  filename = vmsify (filename,0);
#endif

  hash = 0;
  if (filename != 0)
    {
      if (*filename == '\0')
	{
	/* Checking if the directory exists.  */
	  return 1;
	}

      for (p = filename; *p != '\0'; ++p)
	HASH (hash, *p);
      hash %= DIRFILE_BUCKETS;

      /* Search the list of hashed files.  */

      for (df = dir->files[hash]; df != 0; df = df->next)
	{
	  if (strieq (df->name, filename))
	    {
	      return !df->impossible;
	    }
	}
    }

  /* The file was not found in the hashed list.
     Try to read the directory further.  */

  if (dir->dirstream == 0)
    {
#ifdef WINDOWS32
      /*
       * Check to see if directory has changed since last read. FAT
       * filesystems force a rehash always as mtime does not change
       * on directories (ugh!).
       */
      if (dir->path_key &&
          (dir->fs_flags & FS_FAT ||
           (stat(dir->path_key, &st) == 0 &&
            st.st_mtime > dir->mtime))) {

        /* reset date stamp to show most recent re-process */
        dir->mtime = st.st_mtime;

        /* make sure directory can still be opened */
        dir->dirstream = opendir(dir->path_key);

        if (dir->dirstream)
          rehash = 1;
        else
          return 0; /* couldn't re-read - fail */