ltdl.c

sdcc是为51等小型嵌入式cpu设计的c语言编译器支持数种不同类型的cpu


/* --- DYNAMIC MODULE LOADING --- */


/* The type of a function used at each iteration of  foreach_dirinpath().  */
typedef int     foreach_callback_func LT_PARAMS((char *filename, lt_ptr data1,
                                                 lt_ptr data2));

static  int     foreach_dirinpath     LT_PARAMS((const char *search_path,
                                                 const char *base_name,
                                                 foreach_callback_func *func,
                                                 lt_ptr data1, lt_ptr data2));

static  int     find_file_callback    LT_PARAMS((char *filename, lt_ptr data,
                                                 lt_ptr ignored));
static  int     find_handle_callback  LT_PARAMS((char *filename, lt_ptr data,
                                                 lt_ptr ignored));
static  int     foreachfile_callback  LT_PARAMS((char *filename, lt_ptr data1,
                                                 lt_ptr data2));


static  int     canonicalize_path     LT_PARAMS((const char *path,
                                                 char **pcanonical));
static  int     argzize_path          LT_PARAMS((const char *path,
                                                 char **pargz,
                                                 size_t *pargz_len));
static  FILE   *find_file             LT_PARAMS((const char *search_path,
                                                 const char *base_name,
                                                 char **pdir));
static  lt_dlhandle *find_handle      LT_PARAMS((const char *search_path,
                                                 const char *base_name,
                                                 lt_dlhandle *handle));
static  int     find_module           LT_PARAMS((lt_dlhandle *handle,
                                                 const char *dir,
                                                 const char *libdir,
                                                 const char *dlname,
                                                 const char *old_name,
                                                 int installed));
static  int     free_vars             LT_PARAMS((char *dlname, char *oldname,
                                                 char *libdir, char *deplibs));
static  int     load_deplibs          LT_PARAMS((lt_dlhandle handle,
                                                 char *deplibs));
static  int     trim                  LT_PARAMS((char **dest,
                                                 const char *str));
static  int     try_dlopen            LT_PARAMS((lt_dlhandle *handle,
                                                 const char *filename));
static  int     tryall_dlopen         LT_PARAMS((lt_dlhandle *handle,
                                                 const char *filename));
static  int     unload_deplibs        LT_PARAMS((lt_dlhandle handle));
static  int     lt_argz_insert        LT_PARAMS((char **pargz,
                                                 size_t *pargz_len,
                                                 char *before,
                                                 const char *entry));
static  int     lt_argz_insertinorder LT_PARAMS((char **pargz,
                                                 size_t *pargz_len,
                                                 const char *entry));
static  int     lt_argz_insertdir     LT_PARAMS((char **pargz,
                                                 size_t *pargz_len,
                                                 const char *dirnam,
                                                 struct dirent *dp));
static  int     lt_dlpath_insertdir   LT_PARAMS((char **ppath,
                                                 char *before,
                                                 const char *dir));
static  int     list_files_by_dir     LT_PARAMS((const char *dirnam,
                                                 char **pargz,
                                                 size_t *pargz_len));
static  int     file_not_found        LT_PARAMS((void));

static  char           *user_search_path= 0;
static  lt_dlloader    *loaders         = 0;
static  lt_dlhandle     handles         = 0;
static  int             initialized     = 0;

/* Initialize libltdl. */
int
lt_dlinit ()
{
  int         errors   = 0;

  LT_DLMUTEX_LOCK ();

  /* Initialize only at first call. */
  if (++initialized == 1)
    {
      handles = 0;
      user_search_path = 0; /* empty search path */

#if HAVE_LIBDL && !defined(__CYGWIN__)
      errors += lt_dlloader_add (lt_dlloader_next (0), &sys_dl, "dlopen");
#endif
#if HAVE_SHL_LOAD
      errors += lt_dlloader_add (lt_dlloader_next (0), &sys_shl, "dlopen");
#endif
#ifdef __WINDOWS__
      errors += lt_dlloader_add (lt_dlloader_next (0), &sys_wll, "dlopen");
#endif
#ifdef __BEOS__
      errors += lt_dlloader_add (lt_dlloader_next (0), &sys_bedl, "dlopen");
#endif
#if HAVE_DLD
      errors += lt_dlloader_add (lt_dlloader_next (0), &sys_dld, "dld");
#endif
      errors += lt_dlloader_add (lt_dlloader_next (0), &presym, "dlpreload");

      if (presym_init (presym.dlloader_data))
        {
          LT_DLMUTEX_SETERROR (LT_DLSTRERROR (INIT_LOADER));
          ++errors;
        }
      else if (errors != 0)
        {
          LT_DLMUTEX_SETERROR (LT_DLSTRERROR (DLOPEN_NOT_SUPPORTED));
          ++errors;
        }
    }

  LT_DLMUTEX_UNLOCK ();

  return errors;
}

int
lt_dlpreload (preloaded)
     const lt_dlsymlist *preloaded;
{
  int errors = 0;

  if (preloaded)
    {
      errors = presym_add_symlist (preloaded);
    }
  else
    {
      presym_free_symlists();

      LT_DLMUTEX_LOCK ();
      if (default_preloaded_symbols)
        {
          errors = lt_dlpreload (default_preloaded_symbols);
        }
      LT_DLMUTEX_UNLOCK ();
    }

  return errors;
}

int
lt_dlpreload_default (preloaded)
     const lt_dlsymlist *preloaded;
{
  LT_DLMUTEX_LOCK ();
  default_preloaded_symbols = preloaded;
  LT_DLMUTEX_UNLOCK ();
  return 0;
}

int
lt_dlexit ()
{
  /* shut down libltdl */
  lt_dlloader *loader;
  int          errors   = 0;

  LT_DLMUTEX_LOCK ();
  loader = loaders;

  if (!initialized)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (SHUTDOWN));
      ++errors;
      goto done;
    }

  /* shut down only at last call. */
  if (--initialized == 0)
    {
      int       level;

      while (handles && LT_DLIS_RESIDENT (handles))
        {
          handles = handles->next;
        }

      /* close all modules */
      for (level = 1; handles; ++level)
        {
          lt_dlhandle cur = handles;
          int saw_nonresident = 0;

          while (cur)
            {
              lt_dlhandle tmp = cur;
              cur = cur->next;
              if (!LT_DLIS_RESIDENT (tmp))
                saw_nonresident = 1;
              if (!LT_DLIS_RESIDENT (tmp) && tmp->info.ref_count <= level)
                {
                  if (lt_dlclose (tmp))
                    {
                      ++errors;
                    }
                }
            }
          /* done if only resident modules are left */
          if (!saw_nonresident)
            break;
        }

      /* close all loaders */
      while (loader)
        {
          lt_dlloader *next = loader->next;
          lt_user_data data = loader->dlloader_data;
          if (loader->dlloader_exit && loader->dlloader_exit (data))
            {
              ++errors;
            }

          LT_DLMEM_REASSIGN (loader, next);
        }
      loaders = 0;
    }

 done:
  LT_DLMUTEX_UNLOCK ();
  return errors;
}

static int
tryall_dlopen (handle, filename)
     lt_dlhandle *handle;
     const char *filename;
{
  lt_dlhandle    cur;
  lt_dlloader   *loader;
  const char    *saved_error;
  int            errors         = 0;

  LT_DLMUTEX_GETERROR (saved_error);
  LT_DLMUTEX_LOCK ();

  cur    = handles;
  loader = loaders;

  /* check whether the module was already opened */
  while (cur)
    {
      /* try to dlopen the program itself? */
      if (!cur->info.filename && !filename)
        {
          break;
        }

      if (cur->info.filename && filename
          && strcmp (cur->info.filename, filename) == 0)
        {
          break;
        }

      cur = cur->next;
    }

  if (cur)
    {
      ++cur->info.ref_count;
      *handle = cur;
      goto done;
    }

  cur = *handle;
  if (filename)
    {
      cur->info.filename = lt_estrdup (filename);
      if (!cur->info.filename)
        {
          ++errors;
          goto done;
        }
    }
  else
    {
      cur->info.filename = 0;
    }

  while (loader)
    {
      lt_user_data data = loader->dlloader_data;

      cur->module = loader->module_open (data, filename);

      if (cur->module != 0)
        {
          break;
        }
      loader = loader->next;
    }

  if (!loader)
    {
      LT_DLFREE (cur->info.filename);
      ++errors;
      goto done;
    }

  cur->loader   = loader;
  LT_DLMUTEX_SETERROR (saved_error);

 done:
  LT_DLMUTEX_UNLOCK ();

  return errors;
}

static int
tryall_dlopen_module (handle, prefix, dirname, dlname)
     lt_dlhandle *handle;
     const char *prefix;
     const char *dirname;
     const char *dlname;
{
  int      error        = 0;
  char     *filename    = 0;
  size_t   filename_len = 0;
  size_t   dirname_len  = LT_STRLEN (dirname);

  assert (handle);
  assert (dirname);
  assert (dlname);
#ifdef LT_DIRSEP_CHAR
  /* Only canonicalized names (i.e. with DIRSEP chars already converted)
     should make it into this function:  */
  assert (strchr (dirname, LT_DIRSEP_CHAR) == 0);
#endif

  if (dirname[dirname_len -1] == '/')
    --dirname_len;
  filename_len = dirname_len + 1 + LT_STRLEN (dlname);

  /* Allocate memory, and combine DIRNAME and MODULENAME into it.
     The PREFIX (if any) is handled below.  */
  filename  = LT_EMALLOC (char, dirname_len + 1 + filename_len + 1);
  if (!filename)
    return 1;

  sprintf (filename, "%.*s/%s", (int) dirname_len, dirname, dlname);

  /* Now that we have combined DIRNAME and MODULENAME, if there is
     also a PREFIX to contend with, simply recurse with the arguments
     shuffled.  Otherwise, attempt to open FILENAME as a module.  */
  if (prefix)
    {
      error += tryall_dlopen_module (handle,
                                     (const char *) 0, prefix, filename);
    }
  else if (tryall_dlopen (handle, filename) != 0)
    {
      ++error;
    }

  LT_DLFREE (filename);
  return error;
}

static int
find_module (handle, dir, libdir, dlname, old_name, installed)
     lt_dlhandle *handle;
     const char *dir;
     const char *libdir;
     const char *dlname;
     const char *old_name;
     int installed;
{
  /* Try to open the old library first; if it was dlpreopened,
     we want the preopened version of it, even if a dlopenable
     module is available.  */
  if (old_name && tryall_dlopen (handle, old_name) == 0)
    {
      return 0;
    }

  /* Try to open the dynamic library.  */
  if (dlname)
    {
      /* try to open the installed module */
      if (installed && libdir)
        {
          if (tryall_dlopen_module (handle,
                                    (const char *) 0, libdir, dlname) == 0)
            return 0;
        }

      /* try to open the not-installed module */
      if (!installed)
        {
          if (tryall_dlopen_module (handle, dir, objdir, dlname) == 0)
            return 0;
        }

      /* maybe it was moved to another directory */
      {
          if (tryall_dlopen_module (handle,
                                    (const char *) 0, dir, dlname) == 0)
            return 0;
      }
    }

  return 1;
}


static int
canonicalize_path (path, pcanonical)
     const char *path;
     char **pcanonical;
{
  char *canonical = 0;

  assert (path && *path);
  assert (pcanonical);

  canonical = LT_EMALLOC (char, 1+ LT_STRLEN (path));
  if (!canonical)
    return 1;

  {
    size_t dest = 0;
    size_t src;
    for (src = 0; path[src] != LT_EOS_CHAR; ++src)
      {
        /* Path separators are not copied to the beginning or end of
           the destination, or if another separator would follow
           immediately.  */
        if (path[src] == LT_PATHSEP_CHAR)
          {
            if ((dest == 0)
                || (path[1+ src] == LT_PATHSEP_CHAR)
                || (path[1+ src] == LT_EOS_CHAR))
              continue;
          }

        /* Anything other than a directory separator is copied verbatim.  */
        if ((path[src] != '/')
#ifdef LT_DIRSEP_CHAR
            && (path[src] != LT_DIRSEP_CHAR)
#endif
            )
          {
            canonical[dest++] = path[src];
          }
        /* Directory separators are converted and copied only if they are
           not at the end of a path -- i.e. before a path separator or
           NULL terminator.  */
        else if ((path[1+ src] != LT_PATHSEP_CHAR)
                 && (path[1+ src] != LT_EOS_CHAR)
#ifdef LT_DIRSEP_CHAR
                 && (path[1+ src] != LT_DIRSEP_CHAR)
#endif
                 && (path[1+ src] != '/'))
          {
            canonical[dest++] = '/';
          }
      }

    /* Add an end-of-string marker at the end.  */
    canonical[dest] = LT_EOS_CHAR;
  }

  /* Assign new value.  */
  *pcanonical = canonical;

  return 0;
}

static int
argzize_path (path, pargz, pargz_len)
     const char *path;
     char **pargz;
     size_t *pargz_len;
{
  error_t error;

  assert (path);
  assert (pargz);
  assert (pargz_len);

  if ((error = argz_create_sep (path, LT_PATHSEP_CHAR, pargz, pargz_len)))
    {
      switch (error)
        {
        case ENOMEM:
          LT_DLMUTEX_SETERROR (LT_DLSTRERROR (NO_MEMORY));
          break;
        default:
          LT_DLMUTEX_SETERROR (LT_DLSTRERROR (UNKNOWN));
          break;
        }

      return 1;
    }

  return 0;
}

/* Repeatedly call FUNC with each LT_PATHSEP_CHAR delimited element
   of SEARCH_PATH and references to DATA1 and DATA2, until FUNC returns
   non-zero or all elements are exhausted.  If BASE_NAME is non-NULL,
   it is appended to each SEARCH_PATH element before FUNC is called.  */
static int
foreach_dirinpath (search_path, base_name, func, data1, data2)
     const char *search_path;
     const char *base_name;
     foreach_callback_func *func;
     lt_ptr data1;
     lt_ptr data2;
{
  int    result         = 0;
  int    filenamesize   = 0;
  size_t lenbase        = LT_STRLEN (base_name);
  size_t argz_len       = 0;
  char *argz            = 0;
  char *filename        = 0;
  char *canonical       = 0;

  LT_DLMUTEX_LOCK ();

  if (!search_path || !*search_path)
    {
      LT_DLMUTEX_SETERROR (LT_DLSTRERROR (FILE_NOT_FOUND));
      goto cleanup;
    }

  if (canonicalize_path (search_path, &canonical) != 0)
    goto cleanup;

  if (argzize_path (canonical, &argz, &argz_len) != 0)
    goto cleanup;

  {
    char *dir_name = 0;
    while ((dir_name = argz_next (argz, argz_len, dir_name)))
      {
        size_t lendir = LT_STRLEN (dir_name);

        if (lendir +1 +lenbase >= filenamesize)
        {
          LT_DLFREE (filename);
          filenamesize  = lendir +1 +lenbase +1; /* "/d" + '/' + "f" + '\0' */