1<?php
  2/**
  3 * WordPress implementation for PHP functions either missing from older PHP versions or not included by default.
  4 *
  5 * This file is loaded extremely early and the functions can be relied upon by drop-ins.
  6 * Ergo, please ensure you do not rely on external functions when writing code for this file.
  7 * Only use functions built into PHP or are defined in this file and have adequate testing
  8 * and error suppression to ensure the file will run correctly and not break websites.
  9 *
 10 * @package PHP
 11 * @access private
 12 */
 13
 14// If gettext isn't available.
 15if ( ! function_exists( '_' ) ) {
 16	/**
 17	 * Compat function to mimic _(), an alias of gettext().
 18	 *
 19	 * @since 0.71
 20	 *
 21	 * @see https://php.net/manual/en/function.gettext.php
 22	 *
 23	 * @param string $message The message being translated.
 24	 * @return string
 25	 */
 26	function _( $message ) {
 27		return $message;
 28	}
 29}
 30
 31/**
 32 * Returns whether PCRE/u (PCRE_UTF8 modifier) is available for use.
 33 *
 34 * @ignore
 35 * @since 4.2.2
 36 * @since 6.9.0 Deprecated the `$set` argument.
 37 * @access private
 38 *
 39 * @param bool $set Deprecated. This argument is no longer used for testing purposes.
 40 */
 41function _wp_can_use_pcre_u( $set = null ) {
 42	static $utf8_pcre = null;
 43
 44	if ( isset( $set ) ) {
 45		_deprecated_argument( __FUNCTION__, '6.9.0' );
 46	}
 47
 48	if ( isset( $utf8_pcre ) ) {
 49		return $utf8_pcre;
 50	}
 51
 52	$utf8_pcre = true;
 53	set_error_handler(
 54		function ( $errno, $errstr ) use ( &$utf8_pcre ) {
 55			if ( str_starts_with( $errstr, 'preg_match():' ) ) {
 56				$utf8_pcre = false;
 57				return true;
 58			}
 59
 60			return false;
 61		},
 62		E_WARNING
 63	);
 64
 65	/*
 66	 * Attempt to compile a PCRE pattern with the PCRE_UTF8 flag. For
 67	 * systems lacking Unicode support this will trigger a warning
 68	 * during compilation, which the error handler will intercept.
 69	 */
 70	preg_match( '//u', '' );
 71	restore_error_handler();
 72
 73	return $utf8_pcre;
 74}
 75
 76/**
 77 * Indicates if a given slug for a character set represents the UTF-8 text encoding.
 78 *
 79 * A charset is considered to represent UTF-8 if it is a case-insensitive match
 80 * of "UTF-8" with or without the hyphen.
 81 *
 82 * Example:
 83 *
 84 *     true  === _is_utf8_charset( 'UTF-8' );
 85 *     true  === _is_utf8_charset( 'utf8' );
 86 *     false === _is_utf8_charset( 'latin1' );
 87 *     false === _is_utf8_charset( 'UTF 8' );
 88 *
 89 *     // Only strings match.
 90 *     false === _is_utf8_charset( [ 'charset' => 'utf-8' ] );
 91 *
 92 * `is_utf8_charset` should be used outside of this file.
 93 *
 94 * @ignore
 95 * @since 6.6.1
 96 *
 97 * @param string $charset_slug Slug representing a text character encoding, or "charset".
 98 *                             E.g. "UTF-8", "Windows-1252", "ISO-8859-1", "SJIS".
 99 *
100 * @return bool Whether the slug represents the UTF-8 encoding.
101 */
102function _is_utf8_charset( $charset_slug ) {
103	if ( ! is_string( $charset_slug ) ) {
104		return false;
105	}
106
107	return (
108		0 === strcasecmp( 'UTF-8', $charset_slug ) ||
109		0 === strcasecmp( 'UTF8', $charset_slug )
110	);
111}
112
113if ( ! function_exists( 'mb_substr' ) ) :
114	/**
115	 * Compat function to mimic mb_substr().
116	 *
117	 * @ignore
118	 * @since 3.2.0
119	 *
120	 * @see _mb_substr()
121	 *
122	 * @param string      $string   The string to extract the substring from.
123	 * @param int         $start    Position to being extraction from in `$string`.
124	 * @param int|null    $length   Optional. Maximum number of characters to extract from `$string`.
125	 *                              Default null.
126	 * @param string|null $encoding Optional. Character encoding to use. Default null.
127	 * @return string Extracted substring.
128	 */
129	function mb_substr( $string, $start, $length = null, $encoding = null ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound
130		return _mb_substr( $string, $start, $length, $encoding );
131	}
132endif;
133
134/**
135 * Internal compat function to mimic mb_substr().
136 *
137 * Only supports UTF-8 and non-shifting single-byte encodings. For all other encodings
138 * expect the substrings to be misaligned. When the given encoding (or the `blog_charset`
139 * if none is provided) isn’t UTF-8 then the function returns the output of {@see \substr()}.
140 *
141 * @ignore
142 * @since 3.2.0
143 *
144 * @param string      $str      The string to extract the substring from.
145 * @param int         $start    Character offset at which to start the substring extraction.
146 * @param int|null    $length   Optional. Maximum number of characters to extract from `$str`.
147 *                              Default null.
148 * @param string|null $encoding Optional. Character encoding to use. Default null.
149 * @return string Extracted substring.
150 */
151function _mb_substr( $str, $start, $length = null, $encoding = null ) {
152	if ( null === $str ) {
153		return '';
154	}
155
156	// The solution below works only for UTF-8; treat all other encodings as byte streams.
157	if ( ! _is_utf8_charset( $encoding ?? get_option( 'blog_charset' ) ) ) {
158		return is_null( $length ) ? substr( $str, $start ) : substr( $str, $start, $length );
159	}
160
161	$total_length = ( $start < 0 || $length < 0 )
162		? _wp_utf8_codepoint_count( $str )
163		: 0;
164
165	$normalized_start = $start < 0
166		? max( 0, $total_length + $start )
167		: $start;
168
169	/*
170	 * The starting offset is provided as characters, which means this needs to
171	 * find how many bytes that many characters occupies at the start of the string.
172	 */
173	$starting_byte_offset = _wp_utf8_codepoint_span( $str, 0, $normalized_start );
174
175	$normalized_length = $length < 0
176		? max( 0, $total_length - $normalized_start + $length )
177		: $length;
178
179	/*
180	 * This is the main step. It finds how many bytes the given length of code points
181	 * occupies in the input, starting at the byte offset calculated above.
182	 */
183	$byte_length = isset( $normalized_length )
184		? _wp_utf8_codepoint_span( $str, $starting_byte_offset, $normalized_length )
185		: ( strlen( $str ) - $starting_byte_offset );
186
187	// The result is a normal byte-level substring using the computed ranges.
188	return substr( $str, $starting_byte_offset, $byte_length );
189}
190
191if ( ! function_exists( 'mb_strlen' ) ) :
192	/**
193	 * Compat function to mimic mb_strlen().
194	 *
195	 * @ignore
196	 * @since 4.2.0
197	 *
198	 * @see _mb_strlen()
199	 *
200	 * @param string      $string   The string to retrieve the character length from.
201	 * @param string|null $encoding Optional. Character encoding to use. Default null.
202	 * @return int String length of `$string`.
203	 */
204	function mb_strlen( $string, $encoding = null ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.stringFound
205		return _mb_strlen( $string, $encoding );
206	}
207endif;
208
209/**
210 * Internal compat function to mimic mb_strlen().
211 *
212 * Only supports UTF-8 and non-shifting single-byte encodings. For all other
213 * encodings expect the counts to be wrong. When the given encoding (or the
214 * `blog_charset` if none is provided) isn’t UTF-8 then the function returns
215 * the byte-count of the provided string.
216 *
217 * @ignore
218 * @since 4.2.0
219 *
220 * @param string      $str      The string to retrieve the character length from.
221 * @param string|null $encoding Optional. Count characters according to this encoding.
222 *                              Default is to consult `blog_charset`.
223 * @return int Count of code points if UTF-8, byte length otherwise.
224 */
225function _mb_strlen( $str, $encoding = null ) {
226	return _is_utf8_charset( $encoding ?? get_option( 'blog_charset' ) )
227		? _wp_utf8_codepoint_count( $str )
228		: strlen( $str );
229}
230
231if ( ! function_exists( 'utf8_encode' ) ) :
232	if ( extension_loaded( 'mbstring' ) ) :
233		/**
234		 * Converts a string from ISO-8859-1 to UTF-8.
235		 *
236		 * @deprecated Use {@see \mb_convert_encoding()} instead.
237		 *
238		 * @since 6.9.0
239		 *
240		 * @param string $iso_8859_1_text Text treated as ISO-8859-1 (latin1) bytes.
241		 * @return string Text converted into a UTF-8.
242		 */
243		function utf8_encode( $iso_8859_1_text ): string {
244			_deprecated_function( __FUNCTION__, '6.9.0', 'mb_convert_encoding' );
245
246			return mb_convert_encoding( $iso_8859_1_text, 'UTF-8', 'ISO-8859-1' );
247		}
248
249	else :
250		/**
251		 * @ignore
252		 * @private
253		 *
254		 * @since 6.9.0
255		 */
256		function utf8_encode( $iso_8859_1_text ): string {
257			_deprecated_function( __FUNCTION__, '6.9.0', 'mb_convert_encoding' );
258
259			return _wp_utf8_encode_fallback( $iso_8859_1_text );
260		}
261
262	endif;
263endif;
264
265if ( ! function_exists( 'utf8_decode' ) ) :
266	if ( extension_loaded( 'mbstring' ) ) :
267		/**
268		 * Converts a string from UTF-8 to ISO-8859-1.
269		 *
270		 * @deprecated Use {@see \mb_convert_encoding()} instead.
271		 *
272		 * @since 6.9.0
273		 *
274		 * @param string $utf8_text Text treated as UTF-8.
275		 * @return string Text converted into ISO-8859-1.
276		 */
277		function utf8_decode( $utf8_text ): string {
278			_deprecated_function( __FUNCTION__, '6.9.0', 'mb_convert_encoding' );
279
280			return mb_convert_encoding( $utf8_text, 'ISO-8859-1', 'UTF-8' );
281		}
282
283	else :
284		/**
285		 * @ignore
286		 * @private
287		 *
288		 * @since 6.9.0
289		 */
290		function utf8_decode( $utf8_text ): string {
291			_deprecated_function( __FUNCTION__, '6.9.0', 'mb_convert_encoding' );
292
293			return _wp_utf8_decode_fallback( $utf8_text );
294		}
295
296	endif;
297endif;
298
299// sodium_crypto_box() was introduced in PHP 7.2.
300if ( ! function_exists( 'sodium_crypto_box' ) ) {
301	require ABSPATH . WPINC . '/sodium_compat/autoload.php';
302}
303
304if ( ! function_exists( 'is_countable' ) ) {
305	/**
306	 * Polyfill for is_countable() function added in PHP 7.3.
307	 *
308	 * Verify that the content of a variable is an array or an object
309	 * implementing the Countable interface.
310	 *
311	 * @since 4.9.6
312	 *
313	 * @param mixed $value The value to check.
314	 * @return bool True if `$value` is countable, false otherwise.
315	 */
316	function is_countable( $value ) {
317		return ( is_array( $value )
318			|| $value instanceof Countable
319			|| $value instanceof SimpleXMLElement
320			|| $value instanceof ResourceBundle
321		);
322	}
323}
324
325if ( ! function_exists( 'array_key_first' ) ) {
326	/**
327	 * Polyfill for array_key_first() function added in PHP 7.3.
328	 *
329	 * Get the first key of the given array without affecting
330	 * the internal array pointer.
331	 *
332	 * @since 5.9.0
333	 *
334	 * @param array $array An array.
335	 * @return string|int|null The first key of array if the array
336	 *                         is not empty; `null` otherwise.
337	 */
338	function array_key_first( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
339		if ( empty( $array ) ) {
340			return null;
341		}
342
343		foreach ( $array as $key => $value ) {
344			return $key;
345		}
346	}
347}
348
349if ( ! function_exists( 'array_key_last' ) ) {
350	/**
351	 * Polyfill for `array_key_last()` function added in PHP 7.3.
352	 *
353	 * Get the last key of the given array without affecting the
354	 * internal array pointer.
355	 *
356	 * @since 5.9.0
357	 *
358	 * @param array $array An array.
359	 * @return string|int|null The last key of array if the array
360	 *.                        is not empty; `null` otherwise.
361	 */
362	function array_key_last( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
363		if ( empty( $array ) ) {
364			return null;
365		}
366
367		end( $array );
368
369		return key( $array );
370	}
371}
372
373if ( ! function_exists( 'array_is_list' ) ) {
374	/**
375	 * Polyfill for `array_is_list()` function added in PHP 8.1.
376	 *
377	 * Determines if the given array is a list.
378	 *
379	 * An array is considered a list if its keys consist of consecutive numbers from 0 to count($array)-1.
380	 *
381	 * @see https://github.com/symfony/polyfill-php81/tree/main
382	 *
383	 * @since 6.5.0
384	 *
385	 * @param array<mixed> $arr The array being evaluated.
386	 * @return bool True if array is a list, false otherwise.
387	 */
388	function array_is_list( $arr ) {
389		if ( ( array() === $arr ) || ( array_values( $arr ) === $arr ) ) {
390			return true;
391		}
392
393		$next_key = -1;
394
395		foreach ( $arr as $k => $v ) {
396			if ( ++$next_key !== $k ) {
397				return false;
398			}
399		}
400
401		return true;
402	}
403}
404
405if ( ! function_exists( 'str_contains' ) ) {
406	/**
407	 * Polyfill for `str_contains()` function added in PHP 8.0.
408	 *
409	 * Performs a case-sensitive check indicating if needle is
410	 * contained in haystack.
411	 *
412	 * @since 5.9.0
413	 *
414	 * @param string $haystack The string to search in.
415	 * @param string $needle   The substring to search for in the `$haystack`.
416	 * @return bool True if `$needle` is in `$haystack`, otherwise false.
417	 */
418	function str_contains( $haystack, $needle ) {
419		if ( '' === $needle ) {
420			return true;
421		}
422
423		return false !== strpos( $haystack, $needle );
424	}
425}
426
427if ( ! function_exists( 'str_starts_with' ) ) {
428	/**
429	 * Polyfill for `str_starts_with()` function added in PHP 8.0.
430	 *
431	 * Performs a case-sensitive check indicating if
432	 * the haystack begins with needle.
433	 *
434	 * @since 5.9.0
435	 *
436	 * @param string $haystack The string to search in.
437	 * @param string $needle   The substring to search for in the `$haystack`.
438	 * @return bool True if `$haystack` starts with `$needle`, otherwise false.
439	 */
440	function str_starts_with( $haystack, $needle ) {
441		if ( '' === $needle ) {
442			return true;
443		}
444
445		return 0 === strpos( $haystack, $needle );
446	}
447}
448
449if ( ! function_exists( 'str_ends_with' ) ) {
450	/**
451	 * Polyfill for `str_ends_with()` function added in PHP 8.0.
452	 *
453	 * Performs a case-sensitive check indicating if
454	 * the haystack ends with needle.
455	 *
456	 * @since 5.9.0
457	 *
458	 * @param string $haystack The string to search in.
459	 * @param string $needle   The substring to search for in the `$haystack`.
460	 * @return bool True if `$haystack` ends with `$needle`, otherwise false.
461	 */
462	function str_ends_with( $haystack, $needle ) {
463		if ( '' === $haystack ) {
464			return '' === $needle;
465		}
466
467		$len = strlen( $needle );
468
469		return substr( $haystack, -$len, $len ) === $needle;
470	}
471}
472
473if ( ! function_exists( 'array_find' ) ) {
474	/**
475	 * Polyfill for `array_find()` function added in PHP 8.4.
476	 *
477	 * Searches an array for the first element that passes a given callback.
478	 *
479	 * @since 6.8.0
480	 *
481	 * @param array    $array    The array to search.
482	 * @param callable $callback The callback to run for each element.
483	 * @return mixed|null The first element in the array that passes the `$callback`, otherwise null.
484	 */
485	function array_find( array $array, callable $callback ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
486		foreach ( $array as $key => $value ) {
487			if ( $callback( $value, $key ) ) {
488				return $value;
489			}
490		}
491
492		return null;
493	}
494}
495
496if ( ! function_exists( 'array_find_key' ) ) {
497	/**
498	 * Polyfill for `array_find_key()` function added in PHP 8.4.
499	 *
500	 * Searches an array for the first key that passes a given callback.
501	 *
502	 * @since 6.8.0
503	 *
504	 * @param array    $array    The array to search.
505	 * @param callable $callback The callback to run for each element.
506	 * @return int|string|null The first key in the array that passes the `$callback`, otherwise null.
507	 */
508	function array_find_key( array $array, callable $callback ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
509		foreach ( $array as $key => $value ) {
510			if ( $callback( $value, $key ) ) {
511				return $key;
512			}
513		}
514
515		return null;
516	}
517}
518
519if ( ! function_exists( 'array_any' ) ) {
520	/**
521	 * Polyfill for `array_any()` function added in PHP 8.4.
522	 *
523	 * Checks if any element of an array passes a given callback.
524	 *
525	 * @since 6.8.0
526	 *
527	 * @param array    $array    The array to check.
528	 * @param callable $callback The callback to run for each element.
529	 * @return bool True if any element in the array passes the `$callback`, otherwise false.
530	 */
531	function array_any( array $array, callable $callback ): bool { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
532		foreach ( $array as $key => $value ) {
533			if ( $callback( $value, $key ) ) {
534				return true;
535			}
536		}
537
538		return false;
539	}
540}
541
542if ( ! function_exists( 'array_all' ) ) {
543	/**
544	 * Polyfill for `array_all()` function added in PHP 8.4.
545	 *
546	 * Checks if all elements of an array pass a given callback.
547	 *
548	 * @since 6.8.0
549	 *
550	 * @param array    $array    The array to check.
551	 * @param callable $callback The callback to run for each element.
552	 * @return bool True if all elements in the array pass the `$callback`, otherwise false.
553	 */
554	function array_all( array $array, callable $callback ): bool { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
555		foreach ( $array as $key => $value ) {
556			if ( ! $callback( $value, $key ) ) {
557				return false;
558			}
559		}
560
561		return true;
562	}
563}
564
565if ( ! function_exists( 'array_first' ) ) {
566	/**
567	 * Polyfill for `array_first()` function added in PHP 8.5.
568	 *
569	 * Returns the first element of an array.
570	 *
571	 * @since 6.9.0
572	 *
573	 * @param array $array The array to get the first element from.
574	 * @return mixed|null The first element of the array, or null if the array is empty.
575	 */
576	function array_first( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
577		if ( empty( $array ) ) {
578			return null;
579		}
580
581		foreach ( $array as $value ) {
582			return $value;
583		}
584	}
585}
586
587if ( ! function_exists( 'array_last' ) ) {
588	/**
589	 * Polyfill for `array_last()` function added in PHP 8.5.
590	 *
591	 * Returns the last element of an array.
592	 *
593	 * @since 6.9.0
594	 *
595	 * @param array $array The array to get the last element from.
596	 * @return mixed|null The last element of the array, or null if the array is empty.
597	 */
598	function array_last( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
599		if ( empty( $array ) ) {
600			return null;
601		}
602
603		return $array[ array_key_last( $array ) ];
604	}
605}
606
607// IMAGETYPE_AVIF constant is only defined in PHP 8.x or later.
608if ( ! defined( 'IMAGETYPE_AVIF' ) ) {
609	define( 'IMAGETYPE_AVIF', 19 );
610}
611
612// IMG_AVIF constant is only defined in PHP 8.x or later.
613if ( ! defined( 'IMG_AVIF' ) ) {
614	define( 'IMG_AVIF', IMAGETYPE_AVIF );
615}
616
617// IMAGETYPE_HEIF constant is only defined in PHP 8.5 or later.
618if ( ! defined( 'IMAGETYPE_HEIF' ) ) {
619	define( 'IMAGETYPE_HEIF', 20 );
620}
621