/*

   +----------------------------------------------------------------------+

   | Zend Engine                                                          |

   +----------------------------------------------------------------------+

   | Copyright © Zend Technologies Ltd., a subsidiary company of          |

   |     Perforce Software, Inc., and Contributors.                       |

   +----------------------------------------------------------------------+

   | This source file is subject to the Modified BSD License that is      |

   | bundled with this package in the file LICENSE, and is available      |

   | through the World Wide Web at <https://www.php.net/license/>.        |

   |                                                                      |

   | SPDX-License-Identifier: BSD-3-Clause                                |

   +----------------------------------------------------------------------+

   | Authors: Gina Peter Banyard <girgias@php.net>                        |

   +----------------------------------------------------------------------+

*/

#include "zend.h"

#include "zend_API.h"

#include "zend_autoload.h"

#include "zend_hash.h"

#include "zend_types.h"

#include "zend_exceptions.h"

#include "zend_string.h"

ZEND_TLS HashTable *zend_class_autoload_functions;

static void zend_autoload_callback_zval_destroy(zval *element)

{

  zend_fcall_info_cache *fcc = Z_PTR_P(element);

  zend_fcc_dtor(fcc);

  efree(fcc);

}

static Bucket *autoload_find_registered_function(const HashTable *autoloader_table, const zend_fcall_info_cache *function_entry)

{

  zend_fcall_info_cache *current_function_entry;

  ZEND_HASH_MAP_FOREACH_PTR(autoloader_table, current_function_entry) {

    if (zend_fcc_equals(current_function_entry, function_entry)) {

      return _p;

    }

  } ZEND_HASH_FOREACH_END();

  return NULL;

}

ZEND_API zend_class_entry *zend_perform_class_autoload(zend_string *class_name, zend_string *lc_name)

{

  if (!zend_class_autoload_functions) {

    return NULL;

  }

  zval zname;

  ZVAL_STR(&zname, class_name);

  const HashTable *class_autoload_functions = zend_class_autoload_functions;

  /* Cannot use ZEND_HASH_MAP_FOREACH_PTR here as autoloaders may be

   * added/removed during autoloading. */

  HashPosition pos;

  zend_hash_internal_pointer_reset_ex(class_autoload_functions, &pos);

  while (true) {

    zend_fcall_info_cache *func_info = zend_hash_get_current_data_ptr_ex(class_autoload_functions, &pos);

    if (!func_info) {

      break;

    }

    zend_call_known_fcc(func_info, /* retval */ NULL, /* param_count */ 1, /* params */ &zname, /* named_params */ NULL);

    if (EG(exception)) {

      return NULL;

    }

    if (ZSTR_HAS_CE_CACHE(class_name) && ZSTR_GET_CE_CACHE(class_name)) {

      return (zend_class_entry*)ZSTR_GET_CE_CACHE(class_name);

    }

    zend_class_entry *ce = zend_hash_find_ptr(EG(class_table), lc_name);

    if (ce) {

      return ce;

    }

    zend_hash_move_forward_ex(class_autoload_functions, &pos);

  }

  return NULL;

}

/* Needed for compatibility with spl_register_autoload() */

ZEND_API void zend_autoload_register_class_loader(zend_fcall_info_cache *fcc, bool prepend)

{

  ZEND_ASSERT(ZEND_FCC_INITIALIZED(*fcc));

  if (!zend_class_autoload_functions) {

    ALLOC_HASHTABLE(zend_class_autoload_functions);

    zend_hash_init(zend_class_autoload_functions, 1, NULL, zend_autoload_callback_zval_destroy, false);

    /* Initialize as non-packed hash table for prepend functionality. */

    zend_hash_real_init_mixed(zend_class_autoload_functions);

  }

  ZEND_ASSERT(

    fcc->function_handler->type != ZEND_INTERNAL_FUNCTION

    || !zend_string_equals_literal(fcc->function_handler->common.function_name, "spl_autoload_call")

  );

  /* If function is already registered, don't do anything */

  if (autoload_find_registered_function(zend_class_autoload_functions, fcc)) {

    /* Release potential call trampoline */

    zend_release_fcall_info_cache(fcc);

    return;

  }

  zend_fcc_addref(fcc);

  zend_hash_next_index_insert_mem(zend_class_autoload_functions, fcc, sizeof(zend_fcall_info_cache));

  if (prepend && zend_hash_num_elements(zend_class_autoload_functions) > 1) {

    /* Move the newly created element to the head of the hashtable */

    ZEND_ASSERT(!HT_IS_PACKED(zend_class_autoload_functions));

    Bucket tmp = zend_class_autoload_functions->arData[zend_class_autoload_functions->nNumUsed-1];

    memmove(zend_class_autoload_functions->arData + 1, zend_class_autoload_functions->arData, sizeof(Bucket) * (zend_class_autoload_functions->nNumUsed - 1));

    zend_class_autoload_functions->arData[0] = tmp;

    zend_hash_rehash(zend_class_autoload_functions);

  }

}

ZEND_API bool zend_autoload_unregister_class_loader(const zend_fcall_info_cache *fcc) {

  if (zend_class_autoload_functions) {

    Bucket *p = autoload_find_registered_function(zend_class_autoload_functions, fcc);

    if (p) {

      zend_hash_del_bucket(zend_class_autoload_functions, p);

      return true;

    }

  }

  return false;

}

/* We do not return a HashTable* because zend_empty_array is not collectable,

 * therefore the zval holding this value must do so. Something that ZVAL_EMPTY_ARRAY(); does. */

ZEND_API void zend_autoload_fcc_map_to_callable_zval_map(zval *return_value) {

  if (zend_class_autoload_functions) {

    zend_fcall_info_cache *fcc;

    zend_array *map = zend_new_array(zend_hash_num_elements(zend_class_autoload_functions));

    ZEND_HASH_MAP_FOREACH_PTR(zend_class_autoload_functions, fcc) {

      zval tmp;

      zend_get_callable_zval_from_fcc(fcc, &tmp);

      zend_hash_next_index_insert(map, &tmp);

    } ZEND_HASH_FOREACH_END();

    RETURN_ARR(map);

  }

  RETURN_EMPTY_ARRAY();

}

/* Only for deprecated strange behaviour of spl_autoload_unregister() */

ZEND_API void zend_autoload_clean_class_loaders(void)

{

  if (zend_class_autoload_functions) {

    /* Don't destroy the hash table, as we might be iterating over it right now. */

    zend_hash_clean(zend_class_autoload_functions);

  }

}

void zend_autoload_shutdown(void)

{

  if (zend_class_autoload_functions) {

    zend_hash_destroy(zend_class_autoload_functions);

    FREE_HASHTABLE(zend_class_autoload_functions);

    zend_class_autoload_functions = NULL;

  }

}