ltdl.c

MSYS在windows下模拟了一个类unix的终端

     lt_ptr data;
     lt_ptr ignored;
{
  lt_dlhandle  *handle		= (lt_dlhandle *) data;
  int		notfound	= access (filename, R_OK);

  /* Bail out if file cannot be read...  */
  if (notfound)
    return 0;

  /* Try to dlopen the file, but do not continue searching in any
     case.  */
  if (tryall_dlopen (handle, filename) != 0)
    *handle = 0;

  return 1;
}

/* If HANDLE was found return it, otherwise return 0.  If HANDLE was
   found but could not be opened, *HANDLE will be set to 0.  */
static lt_dlhandle *
find_handle (search_path, base_name, handle)
     const char *search_path;
     const char *base_name;
     lt_dlhandle *handle;
{
  if (!search_path)
    return 0;

  if (!foreach_dirinpath (search_path, base_name, find_handle_callback,
			  handle, 0))
    return 0;

  return handle;
}

static int
load_deplibs (handle, deplibs)
     lt_dlhandle handle;
     char *deplibs;
{
#if LTDL_DLOPEN_DEPLIBS
  char	*p, *save_search_path = 0;
  int   depcount = 0;
  int	i;
  char	**names = 0;
#endif
  int	errors = 0;

  handle->depcount = 0;

#if LTDL_DLOPEN_DEPLIBS
  if (!deplibs)
    {
      return errors;
    }
  ++errors;

  LT_DLMUTEX_LOCK ();
  if (user_search_path)
    {
      save_search_path = lt_estrdup (user_search_path);
      if (!save_search_path)
	goto cleanup;
    }

  /* extract search paths and count deplibs */
  p = deplibs;
  while (*p)
    {
      if (!isspace ((int) *p))
	{
	  char *end = p+1;
	  while (*end && !isspace((int) *end))
	    {
	      ++end;
	    }

	  if (strncmp(p, "-L", 2) == 0 || strncmp(p, "-R", 2) == 0)
	    {
	      char save = *end;
	      *end = 0; /* set a temporary string terminator */
	      if (lt_dladdsearchdir(p+2))
		{
		  goto cleanup;
		}
	      *end = save;
	    }
	  else
	    {
	      ++depcount;
	    }

	  p = end;
	}
      else
	{
	  ++p;
	}
    }

  /* restore the old search path */
  LT_DLFREE (user_search_path);
  user_search_path = save_search_path;

  LT_DLMUTEX_UNLOCK ();

  if (!depcount)
    {
      errors = 0;
      goto cleanup;
    }

  names = LT_EMALLOC (char *, depcount * sizeof (char*));
  if (!names)
    goto cleanup;

  /* now only extract the actual deplibs */
  depcount = 0;
  p = deplibs;
  while (*p)
    {
      if (isspace ((int) *p))
	{
	  ++p;
	}
      else
	{
	  char *end = p+1;
	  while (*end && !isspace ((int) *end))
	    {
	      ++end;
	    }

	  if (strncmp(p, "-L", 2) != 0 && strncmp(p, "-R", 2) != 0)
	    {
	      char *name;
	      char save = *end;
	      *end = 0; /* set a temporary string terminator */
	      if (strncmp(p, "-l", 2) == 0)
		{
		  size_t name_len = 3+ /* "lib" */ LT_STRLEN (p + 2);
		  name = LT_EMALLOC (char, 1+ name_len);
		  if (name)
		    sprintf (name, "lib%s", p+2);
		}
	      else
		name = lt_estrdup(p);

	      if (!name)
		goto cleanup_names;

	      names[depcount++] = name;
	      *end = save;
	    }
	  p = end;
	}
    }

  /* load the deplibs (in reverse order)
     At this stage, don't worry if the deplibs do not load correctly,
     they may already be statically linked into the loading application
     for instance.  There will be a more enlightening error message
     later on if the loaded module cannot resolve all of its symbols.  */
  if (depcount)
    {
      int	j = 0;

      handle->deplibs = (lt_dlhandle*) LT_EMALLOC (lt_dlhandle *, depcount);
      if (!handle->deplibs)
	goto cleanup;

      for (i = 0; i < depcount; ++i)
	{
	  handle->deplibs[j] = lt_dlopenext(names[depcount-1-i]);
	  if (handle->deplibs[j])
	    {
	      ++j;
	    }
	}

      handle->depcount	= j;	/* Number of successfully loaded deplibs */
      errors		= 0;
    }

 cleanup_names:
  for (i = 0; i < depcount; ++i)
    {
      LT_DLFREE (names[i]);
    }

 cleanup:
  LT_DLFREE (names);
#endif

  return errors;
}

static int
unload_deplibs (handle)
     lt_dlhandle handle;
{
  int i;
  int errors = 0;

  if (handle->depcount)
    {
      for (i = 0; i < handle->depcount; ++i)
	{
	  if (!LT_DLIS_RESIDENT (handle->deplibs[i]))
	    {
	      errors += lt_dlclose (handle->deplibs[i]);
	    }
	}
    }

  return errors;
}

static int
trim (dest, str)
     char **dest;
     const char *str;
{
  /* remove the leading and trailing "'" from str
     and store the result in dest */
  const char *end   = strrchr (str, '\'');
  size_t len	    = LT_STRLEN (str);
  char *tmp;

  LT_DLFREE (*dest);

  if (len > 3 && str[0] == '\'')
    {
      tmp = LT_EMALLOC (char, end - str);
      if (!tmp)
	return 1;

      strncpy(tmp, &str[1], (end - str) - 1);
      tmp[len-3] = LT_EOS_CHAR;
      *dest = tmp;
    }
  else
    {
      *dest = 0;
    }

  return 0;
}

static int
free_vars (dlname, oldname, libdir, deplibs)
     char *dlname;
     char *oldname;
     char *libdir;
     char *deplibs;
{
  LT_DLFREE (dlname);
  LT_DLFREE (oldname);
  LT_DLFREE (libdir);
  LT_DLFREE (deplibs);

  return 0;
}

static int
try_dlopen (phandle, filename)
     lt_dlhandle *phandle;
     const char *filename;
{
  const char *	ext		= 0;
  const char *	saved_error	= 0;
  char *	canonical	= 0;
  char *	base_name	= 0;
  char *	dir		= 0;
  char *	name		= 0;
  int		errors		= 0;
  lt_dlhandle	newhandle;

  assert (phandle);
  assert (*phandle == 0);

  LT_DLMUTEX_GETERROR (saved_error);

  /* dlopen self? */
  if (!filename)
    {
      *phandle = (lt_dlhandle) LT_EMALLOC (struct lt_dlhandle_struct, 1);
      if (*phandle == 0)
	return 1;

      memset (*phandle, 0, sizeof(struct lt_dlhandle_struct));
      newhandle	= *phandle;

      /* lt_dlclose()ing yourself is very bad!  Disallow it.  */
      LT_DLSET_FLAG (*phandle, LT_DLRESIDENT_FLAG);

      if (tryall_dlopen (&newhandle, 0) != 0)
	{
	  LT_DLFREE (*phandle);
	  return 1;
	}

      goto register_handle;
    }

  assert (filename && *filename);

  /* Doing this immediately allows internal functions to safely
     assume only canonicalized paths are passed.  */
  if (canonicalize_path (filename, &canonical) != 0)
    {
      ++errors;
      goto cleanup;
    }

  /* If the canonical module name is a path (relative or absolute)
     then split it into a directory part and a name part.  */
  base_name = strrchr (canonical, '/');
  if (base_name)
    {
      size_t dirlen = (1+ base_name) - canonical;

      dir = LT_EMALLOC (char, 1+ dirlen);
      if (!dir)
	{
	  ++errors;
	  goto cleanup;
	}

      strncpy (dir, canonical, dirlen);
      dir[dirlen] = LT_EOS_CHAR;

      ++base_name;
    }
  else
    LT_DLMEM_REASSIGN (base_name, canonical);

  assert (base_name && *base_name);

  /* Check whether we are opening a libtool module (.la extension).  */
  ext = strrchr (base_name, '.');
  if (ext && strcmp (ext, archive_ext) == 0)
    {
      /* this seems to be a libtool module */
      FILE *	file	 = 0;
      char *	dlname	 = 0;
      char *	old_name = 0;
      char *	libdir	 = 0;
      char *	deplibs	 = 0;
      char *    line	 = 0;
      size_t	line_len;

      /* if we can't find the installed flag, it is probably an
	 installed libtool archive, produced with an old version
	 of libtool */
      int	installed = 1;

      /* extract the module name from the file name */
      name = LT_EMALLOC (char, ext - base_name + 1);
      if (!name)
	{
	  ++errors;
	  goto cleanup;
	}

      /* canonicalize the module name */
      {
        size_t i;
        for (i = 0; i < ext - base_name; ++i)
	  {
	    if (isalnum ((int)(base_name[i])))
	      {
	        name[i] = base_name[i];
	      }
	    else
	      {
	        name[i] = '_';
	      }
	  }
        name[ext - base_name] = LT_EOS_CHAR;
      }

      /* Now try to open the .la file.  If there is no directory name
         component, try to find it first in user_search_path and then other
         prescribed paths.  Otherwise (or in any case if the module was not
         yet found) try opening just the module name as passed.  */
      if (!dir)
	{
	  const char *search_path;

	  LT_DLMUTEX_LOCK ();
	  search_path = user_search_path;
	  if (search_path)
	    file = find_file (user_search_path, base_name, &dir);
	  LT_DLMUTEX_UNLOCK ();

	  if (!file)
	    {
	      search_path = getenv (LTDL_SEARCHPATH_VAR);
	      if (search_path)
		file = find_file (search_path, base_name, &dir);
	    }

#ifdef LTDL_SHLIBPATH_VAR
	  if (!file)
	    {
	      search_path = getenv (LTDL_SHLIBPATH_VAR);
	      if (search_path)
		file = find_file (search_path, base_name, &dir);
	    }
#endif
#ifdef LTDL_SYSSEARCHPATH
	  if (!file && sys_search_path)
	    {
	      file = find_file (sys_search_path, base_name, &dir);
	    }
#endif
	}
      if (!file)
	{
	  file = fopen (filename, LT_READTEXT_MODE);
	}

      /* If we didn't find the file by now, it really isn't there.  Set
	 the status flag, and bail out.  */
      if (!file)
	{
	  LT_DLMUTEX_SETERROR (LT_DLSTRERROR (FILE_NOT_FOUND));
	  ++errors;
	  goto cleanup;
	}

      line_len = LT_FILENAME_MAX;
      line = LT_EMALLOC (char, line_len);
      if (!line)
	{
	  fclose (file);
	  ++errors;
	  goto cleanup;
	}

      /* read the .la file */
      while (!feof (file))
	{
	  if (!fgets (line, (int) line_len, file))
	    {
	      break;
	    }

	  /* Handle the case where we occasionally need to read a line
	     that is longer than the initial buffer size.  */
	  while ((line[LT_STRLEN(line) -1] != '\n') && (!feof (file)))
	    {
	      line = LT_DLREALLOC (char, line, line_len *2);
	      if (!fgets (&line[line_len -1], (int) line_len +1, file))
		{
		  break;
		}
	      line_len *= 2;
	    }

	  if (line[0] == '\n' || line[0] == '#')
	    {
	      continue;
	    }

#undef  STR_DLNAME
#define STR_DLNAME	"dlname="
	  if (strncmp (line, STR_DLNAME, sizeof (STR_DLNAME) - 1) == 0)
	    {
	      errors += trim (&dlname, &line[sizeof (STR_DLNAME) - 1]);
	    }

#undef  STR_OLD_LIBRARY
#define STR_OLD_LIBRARY	"old_library="
	  else if (strncmp (line, STR_OLD_LIBRARY,
			    sizeof (STR_OLD_LIBRARY) - 1) == 0)
	    {
	      errors += trim (&old_name, &line[sizeof (STR_OLD_LIBRARY) - 1]);
	    }
#undef  STR_LIBDIR
#define STR_LIBDIR	"libdir="
	  else if (strncmp (line, STR_LIBDIR, sizeof (STR_LIBDIR) - 1) == 0)
	    {
	      errors += trim (&libdir, &line[sizeof(STR_LIBDIR) - 1]);
	    }

#undef  STR_DL_DEPLIBS
#define STR_DL_DEPLIBS	"dependency_libs="
	  else if (strncmp (line, STR_DL_DEPLIBS,
			    sizeof (STR_DL_DEPLIBS) - 1) == 0)
	    {
	      errors += trim (&deplibs, &line[sizeof (STR_DL_DEPLIBS) - 1]);
	    }
	  else if (strcmp (line, "installed=yes\n") == 0)
	    {
	      installed = 1;
	    }
	  else if (strcmp (line, "installed=no\n") == 0)
	    {
	      installed = 0;
	    }

#undef  STR_LIBRARY_NAMES
#define STR_LIBRARY_NAMES "library_names="
	  else if (! dlname && strncmp (line, STR_LIBRARY_NAMES,
					sizeof (STR_LIBRARY_NAMES) - 1) == 0)
	    {
	      char *last_libname;
	      errors += trim (&dlname, &line[sizeof (STR_LIBRARY_NAMES) - 1]);
	      if (!errors
		  && dlname
		  && (last_libname = strrchr (dlname, ' ')) != 0)
		{
		  last_libname = lt_estrdup (last_libname + 1);
		  if (!last_libname)
		    {
		      ++errors;
		      goto cleanup;
		    }
		  LT_DLMEM_REASSIGN (dlname, last_libname);
		}
	    }

	  if (errors)
	    break;
	}

      fclose (file);
      LT_DLFREE (line);

      /* allocate the handle */
      *phandle = (lt_dlhandle) LT_EMALLOC (struct lt_dlhandle_struct, 1);
      if (*phandle == 0)
	++errors;

      if (errors)
	{
	  free_vars (dlname, old_name, libdir, deplibs);
	  LT_DLFREE (*phandle);
	  goto cleanup;
	}

      assert (*phandle);

      memset (*phandle, 0, sizeof(struct lt_dlhandle_struct));
      if (load_deplibs (*phandle, deplibs) == 0)
	{
	  newhandle = *phandle;
	  /* find_module may replace newhandle */
	  if (find_module (&newhandle, dir, libdir, dlname, old_name, installed))
	    {
	      unload_deplibs (*phandle);
	      ++errors;
	    }
	}
      else
	{
	  ++errors;
	}

      free_vars (dlname, old_name, libdir, deplibs);
      if (errors)
	{
	  LT_DLFREE (*phandle);
	  goto cleanup;
	}

      if (*phandle != newhandle)
	{
	  unload_deplibs (*phandle);
	}
    }
  else
    {
      /* not a libtool module */
      *phandle = (lt_dlhandle) LT_EMALLOC (struct lt_dlhandle_struct, 1);
      if (*phandle == 0)
	{
	  ++errors;
	  goto cleanup;
	}

      memset (*phandle, 0, sizeof (struct lt_dlhandle_struct));
      newhandle = *phandle;

      /* If the module has no directory name component, try to find it
	 first in user_search_path and then other prescribed paths.
	 Otherwise (or in any case if the module was not yet found) try
	 opening just the module name as passed.  */
      if ((dir || (!find_handle (user_search_path, base_name, &newhandle)
		   && !find_handle (getenv (LTDL_SEARCHPATH_VAR), base_name,
				    &newhandle)
#ifdef LTDL_SHLIBPATH_VAR
		   && !find_handle (getenv (LTDL_SHLIBPATH_VAR), base_name,
				    &newhandle)
#endif
#ifdef LTDL_SYSSEARCHPATH
		   && !find_handle (sys_search_path, base_name,