UPGRADING

PHP 8.4 UPGRADE NOTES

1. Backward Incompatible Changes
2. New Features
3. Changes in SAPI modules
4. Deprecated Functionality
5. Changed Functions
6. New Functions
7. New Classes and Interfaces
8. Removed Extensions and SAPIs
9. Other Changes to Extensions
10. New Global Constants
11. Changes to INI File Handling
12. Windows Support
13. Other Changes
14. Performance Improvements

========================================
1. Backward Incompatible Changes
========================================

- CLI:
  . The builtin server looks for an index file recursively by traversing parent
    directories in case the specified file cannot be located. This process was
    previously skipped if the path looked like it was referring to a file, i.e.
    if the last path component contained a period. In that case, a 404 error was
    returned. The behavior has been changed to look for an index file in all
    cases.

- Core:
  . The type of PHP_DEBUG and PHP_ZTS constants changed to bool.

- DOM:
  . New methods and constants were added to some DOM classes. If you inherit
    from these and you happen to have a method or property with the same name,
    you might encounter errors if the declaration is incompatible.
    Consult sections 2. New Features and 6. New Functions for a list of
    newly implemented methods and constants.
  . Some DOM methods previously returned false or a PHP_ERR DOMException if a new
    node could not be allocated. They consistently throw an INVALID_STATE_ERR
    DOMException now. This situation is extremely unlikely though and probably
    will not affect you. As a result DOMImplementation::createDocument() now has
    a tentative return type of DOMDocument instead of DOMDocument|false.
  . Previously, DOMXPath objects could be cloned, but resulted in an unusable
    object. This is no longer possible, and cloning a DOMXPath object now throws
    an error.

- Intl:
  . resourcebundle_get(), ResourceBundle::get(), and accessing offsets on a
    ResourceBundle object now throw:
    - TypeError for invalid offset types
    - ValueError for an empty string
    - ValueError if the integer index does not fit in a signed 32 bit integer

- MBString:
  . mb_encode_numericentity() and mb_decode_numericentity() now check that
    the $map is only composed of integers, if not a ValueError is thrown.
  . mb_http_input() now always throws a ValueError if the $type is invalid.
  . On invalid strings (those with encoding errors), mb_substr() now interprets
    character indices in the same manner as most other mbstring functions. This
    means that character indices returned by mb_strpos() can be passed to mb_substr().
  . For SJIS-Mac (MacJapanese) strings, character indices passed to mb_substr() now
    refer to the indices of the Unicode codepoints which are produced when the string
    is converted to Unicode. This is significant because around 40 SJIS-Mac characters
    convert to a sequence of multiple Unicode codepoints.

- Opcache:
  . The JIT config defaults changed from opcache.jit=tracing and
    opcache.jit_buffer_size=0 to opcache.jit=disable and
    opcache.jit_buffer_size=64M, respectively. This does not affect the default
    behavior, the JIT is still disabled by default. However, it is now disabled
    through the opcache.jit setting, rather than opcache.jit_buffer_size. This
    may affect users who previously enabled JIT through opcache.jit_buffer_size
    exclusively, without also specifying a JIT mode using opcache.jit. To enable
    JIT, set the opcache.jit config value accordingly.
  . The maximum value of the opcache.interned_strings_buffer setting on 64bit
    architectures is now 32767 (it was previously 4095).

- PCRE:
  . The bundled pcre2lib has been updated to version 10.43.
    As a consequence, this means {,3} is now recognized as a quantifier instead
    of as text. Furthermore, the meaning of some character classes in UCP mode
    has changed. Consult https://github.com/PCRE2Project/pcre2/blob/master/NEWS
    for a full changelog.

- PDO_DBLIB:
  . setAttribute, DBLIB_ATTR_STRINGIFY_UNIQUEIDENTIFIER and DBLIB_ATTR_DATETIME_CONVERT
    have been changed to set value as a bool.

- PDO_FIREBIRD:
  . getAttribute, ATTR_AUTOCOMMIT has been changed to get the value as a bool.

- PDO_MYSQL:
  . getAttribute, ATTR_AUTOCOMMIT, ATTR_EMULATE_PREPARES, MYSQL_ATTR_DIRECT_QUERY have
    been changed to get values ​​as bool.

- PDO_PGSQL:
  . The DSN's credentials, when set, are given priority over their PDO
    constructor counterparts, being closer to the documentation states.

- PCNTL:
  . The functions pcntl_sigprocmask(), pcntl_sigwaitinfo() and
    pcntl_sigtimedwait() now throw:
    - A ValueError if the $signals array is empty (except for
      pcntl_sigprocmask() if the $mode is SIG_SETMASK).
    - A TypeError if a value of the $signals array is not an integer
    - A ValueError if a value of the $signals array is not a valid signal number
    Moreover, those functions now always return false on failure.
    In some case previously it could return the value -1.
  . The function pcntl_sigprocmask() will also now throw:
    - A ValueError if $mode is not one of SIG_BLOCK, SIG_UNBLOCK, or SIG_SETMASK
  . The function pcntl_sigtimedwait() will also now throw:
    - A ValueError if $seconds is less than 0
    - A ValueError if $nanoseconds is less than 0 or greater than 1e9
    - A ValueError if both $seconds and $nanoseconds are 0

- SimpleXML:
  . Get methods called, or casting to a string on a SimpleXMLElement will no
    longer implicitly reset the iterator data, unless explicitly rewound.
    For example, casting an element to a string within a foreach loop would
    cause an infinite loop because it destroyed the current iterator data.
    This is no longer the case as a consequence of the bugfixes for GH-12192,
    GH-12208, #55098.
  . Calling simplexml_import_dom() with a non-XML object now throws a TypeError
    instead of a ValueError.

- SPL:
  . Out of bounds accesses in SplFixedArray now throw an exception of type
    OutOfBoundsException instead of RuntimeException. As OutOfBoundsException
    is a child class of RuntimeException, code that uses RuntimeException
    continues to function.

- Standard:
  . round() now validates the value of the $mode parameter and throws a ValueError
    for invalid modes. Previously invalid modes would have been interpreted as
    PHP_ROUND_HALF_UP.
  . strcspn() with empty $characters now returns the length of the string instead
    of incorrectly stopping at the first NUL character. See GH-12592.
  . base64_encode now have a $padding option (true by default) to allow
    encoding without the padding character '='.

- XML:
  . The xml_set_*_handler() functions now declare and check for an effective
    signature of callable|string|null for the $handler parameters.
    Moreover, values of type string that correspond to method names,
    of object set with xml_set_object() are now checked to see if the method
    exists on the class of the previously passed object.
    This means that xml_set_object() must now always be called prior to setting
    method names as callables.
    Passing an empty string to disable the handler is still allowed,
    but not recommended.

- XSL:
  . XSLTProcessor::setParameter() will now throw a ValueError when its arguments
    contain null bytes. This never actually worked correctly in the first place,
    which is why it throws an exception nowadays.
  . Failure to call a PHP function callback during evaluation now throws
    instead of emitting a warning.
    RFC: https://wiki.php.net/rfc/improve_callbacks_dom_and_xsl
  . Calling XSLTProcessor::importStyleSheet() with a non-XML object now throws
    a TypeError instead of a ValueError.

========================================
2. New Features
========================================

- Core:
  . Added request_parse_body() function that allows parsing RFC1867 (multipart)
    requests in non-POST HTTP requests.
    RFC: https://wiki.php.net/rfc/rfc1867-non-post
  . Getting the debug info for WeakReference will now also output the object
    it references, or null if the reference is no longer valid.

- Curl:
  . curl_version() returns an additional feature_list value, which is an
    associative array of all known Curl features, and whether they are
    supported (true) or not (false).

- Date:
  . Added static methods
    DateTime[Immutable]::createFromTimestamp(int|float $timestamp): static.
  . Added method DateTime[Immutable]::getMicrosecond(): int.
  . Added method
    DateTime[Immutable]::setMicrosecond(int $microsecond): static.

- DOM:
  . Added constant DOMNode::DOCUMENT_POSITION_DISCONNECTED.
  . Added constant DOMNode::DOCUMENT_POSITION_PRECEDING.
  . Added constant DOMNode::DOCUMENT_POSITION_FOLLOWING.
  . Added constant DOMNode::DOCUMENT_POSITION_CONTAINS.
  . Added constant DOMNode::DOCUMENT_POSITION_CONTAINED_BY.
  . Added constant DOMNode::DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC.
  . It is now possible to pass any callable to registerPhpFunctions().
    RFC: https://wiki.php.net/rfc/improve_callbacks_dom_and_xsl

- FPM:
  . Flushing headers without a body will now succeed. See GH-12785.

- Intl:
  . NumberFormatter::ROUND_HALFODD added to complement existing
    NumberFormatter::ROUND_HALFEVEN functionality.

- Phar:
  . Added support for the unix timestamp extension for zip archives.

- PCRE:
  . The bundled pcre2lib has been updated to version 10.43.
    As a consequence, LoongArch JIT support has been added, spaces
    are now allowed between braces in Perl-compatible items, and
    variable-length lookbehind assertions are now supported.
  . Added support for the "r" (PCRE2_EXTRA_CASELESS_RESTRICT) modifier, as well
    as the (?r) mode modifier. When enabled along with the case-insensitive
    modifier ("i"), the expression locks out mixing of ASCII and non-ASCII
    characters.

- PDO:
  . Added support for driver-specific subclasses.
    RFC: https://wiki.php.net/rfc/pdo_driver_specific_subclasses
    This RFC adds subclasses for PDO in order to better support
    database-specific functionalities. The new classes are
    instantiatable either via calling the PDO::connect() method
    or by invoking their constructor directly.

- PDO_DBLIB:
  . Added class PdoDbLib.

- PDO_FIREBIRD:
  . Added class PdoFirebird.

- PDO_MYSQL:
  . Added class PdoMysql.

- PDO_ODBC:
  . Added class PdoOdbc.

- PDO_PGSQL:
  . Added class PdoPgsql.

- PDO_SQLITE:
  . Added class PdoSqlite.

- POSIX:
  . Added constant POSIX_SC_CHILD_MAX
  . Added constant POSIX_SC_CLK_TCK

- Reflection:
  . ReflectionAttribute now contains a $name property to improve the debugging
    experience.
  . ReflectionClassConstant::__toString() and ReflectionProperty::__toString()
    now returns the attached doc comments.

- SOAP:
  . Added support for clark notation for namespaces in class map.
    It is now possible to specify entries in a class map with clark notation
    to resolve a type with a specific namespace to a specific class.
    For example: '{http://example.com}foo' => 'FooClass'.
  . Instances of DateTimeInterface that are passed to xsd:datetime or similar
    elements are now serialized as such instead of being serialized as an
    empty string.

- XSL:
  . It is now possible to use parameters that contain both single and double
    quotes.
  . It is now possible to pass any callable to registerPhpFunctions().
    RFC: https://wiki.php.net/rfc/improve_callbacks_dom_and_xsl

========================================
3. Changes in SAPI modules
========================================

========================================
4. Deprecated Functionality
========================================

- Core:
  . Implicitly nullable parameter types are now deprecated.
    RFC: https://wiki.php.net/rfc/deprecate-implicitly-nullable-types

- Curl:
  . The CURLOPT_BINARYTRANSFER constant is deprecated.

- Date:
  . Calling DatePeriod::__construct(string $isostr, int $options = 0) is
    deprecated. Use DatePeriod::createFromISO8601String() instead.

- Intl:
  . Calling intlcal_set() as well as calling IntlCalendar::set() with
    more than 2 arguments is deprecated. Use either IntlCalendar::setDate()
    or IntlCalendar::setDateTime() instead.
  . Calling intlgregcal_create_instance() as well as calling
    IntlGregorianCalendar::__construct() with more than 2 arguments is
    deprecated. Use either IntlGregorianCalendar::createFromDate() or
    IntlGregorianCalendar::createFromDateTime() instead.

- LDAP:
  . Calling ldap_connect() with more than 2 arguments is deprecated. Use
    ldap_connect_wallet() instead.
  . Calling ldap_exop() with more than 4 arguments is deprecated. Use
    ldap_exop_sync() instead.

- PgSQL:
  . Calling pgsql_fetch_result() with 2 arguments is deprecated. Use the
    3-parameter signature with a null $row parameter instead.
  . Calling pg_field_prtlen() with 2 arguments is deprecated. Use the
    3-parameter signature with a null $row parameter instead.
  . Calling pg_field_is_null() with 2 arguments is deprecated. Use the
    3-parameter signature with a null $row parameter instead.

- Reflection:
  . Calling ReflectionMethod::__construct() with 1 argument is deprecated.
    Use ReflectionMethod::createFromMethodName() instead.

- Session:
  . Calling session_set_save_handler() with more than 2 arguments is
    deprecated. Use the 2-parameter signature instead.

- Standard:
  . Calling stream_context_set_option() with 2 arguments is deprecated.
    Use stream_context_set_options() instead.

========================================
5. Changed Functions
========================================

- Core:
  . trigger_error() and user_error() now have a return type of true instead of
    bool.

- DOM:
  . DOMDocument::registerNodeClass() now has a tentative return type of true.
    Previously, the return type was bool but only true could be returned in practice.

- Gettext:
  . bind_textdomain_codeset, textdomain and d(*)gettext functions now throw an exception
    if the domain argument is empty.

- Hash:
  . Changed the return type of hash_update() to true. It was already the case that only
    true could be returned, but the stub was not updated yet.

- Intl:
  . IntlDateFormatter::__construct() throws a ValueError if the locale is invalid.
  . NumberFormatter::__construct() throws a ValueError if the locale is invalid.
  . NumberFormatter::ROUND_TOWARD_ZERO and NumberFormatter::ROUND_AWAY_FROM_ZERO
    have been added as aliases for NumberFormatter::ROUND_DOWN and
    NumberFormatter::ROUND_UP to be consistent with the new PHP_ROUND_* modes.
    RFC: https://wiki.php.net/rfc/new_rounding_modes_to_round_function
  . ResourceBundle::get() now has a tentative return type of:
    ResourceBundle|array|string|int|null

- MBString:
  . The behavior of mb_strcut is more consistent now on invalid UTF-8 and UTF-16
    strings. (For valid UTF-8 and UTF-16 strings, there is no change.)

- OpenSSL:
  . The extra_attributes parameter in openssl_csr_new sets CSR attributes
    instead of subject DN which was incorrectly done previously.
  . The dn parameter in openssl_csr_new allows setting array of values for
    a single entry.
  . New serial_hex parameter added to openssl_csr_sign to allow setting serial
    number in the hexadecimal format.

- Output:
  . Output handler status flags passed to the flags parameter of ob_start
    are now cleared.

- PDO:
  . getAttribute, enabled to get the value of ATTR_STRINGIFY_FETCHES.

- PDO_FIREBIRD:
  . getAttribute, enabled to get values ​​of FB_ATTR_DATE_FORMAT, FB_ATTR_TIME_FORMAT,
    FB_ATTR_TIMESTAMP_FORMAT.
  . Added new attributes to specify transaction isolation level and access mode.
    Along with these, five constants (PDO::FB_TRANSACTION_ISOLATION_LEVEL,
    PDO::FB_READ_COMMITTED, PDO::FB_REPEATABLE_READ, PDO::FB_SERIALIZABLE,
    PDO::FB_WRITABLE_TRANSACTION) have been added.
  . When using persistent connections, there is now a liveness check in the
    constructor.

- PDO_MYSQL:
  . getAttribute, enabled to get the value of ATTR_FETCH_TABLE_NAMES.

- PGSQL:
  . pg_select, the conditions arguments accepts an empty array and is optional.

- SPL:
  . SplPriorityQueue::insert() and SplPriorityQueue::recoverFromCorruption()
    now has a tentative return type of true
  . SplHeap::insert() and SplHeap::recoverFromCorruption()
    now has a tentative return type of true instead of bool

- Standard:
  . The internal implementation for rounding to integers has been rewritten
    to be easier to verify for correctness and to be easier to maintain.
    Some rounding bugs have been fixed as a result of the rewrite. For
    example previously rounding 0.49999999999999994 to the nearest integer
    would have resulted in 1.0 instead of the correct result 0.0. Additional
    inputs might also be affected and result in different outputs compared to
    earlier PHP versions.
  . The default value of the 'cost' option for PASSWORD_BCRYPT for password_hash()
    has been increased from '10' to '12'.

    RFC: https://wiki.php.net/rfc/bcrypt_cost_2023
  . Four new modes have been added to the round() function: PHP_ROUND_CEILING,
    PHP_ROUND_FLOOR, PHP_ROUND_TOWARD_ZERO, PHP_ROUND_AWAY_FROM_ZERO.

    RFC: https://wiki.php.net/rfc/new_rounding_modes_to_round_function
  . debug_zval_dump() now indicates whether an array is packed.
  . Fixed a bug caused by "pre-rounding" of the round() function. Previously, using
    "pre-rounding" to treat a value like 0.285 (actually 0.28499999999999998) as a
    decimal number and round it to 0.29. However, "pre-rounding" incorrectly rounds
    certain numbers, so this fix removes "pre-rounding" and changes the way numbers
    are compared, so that the values ​​are correctly rounded as decimal numbers.
  . long2ip() now returns string instead of string|false.
  . The maximum precision that can be handled by round() has been extended by
    one digit.
  . output_add_rewrite_var() now uses url_rewriter.hosts instead of
    session.trans_sid_hosts for selecting hosts that will be rewritten.

========================================
6. New Functions
========================================

- DOM:
  . Added DOMNode::compareDocumentPosition().
  . Added DOMXPath::registerPhpFunctionNS().
    RFC: https://wiki.php.net/rfc/improve_callbacks_dom_and_xsl
  . Added DOMXPath::quote() to quote a string for use in an XPath expression.
    Example usage: "//span[contains(text()," . $xpath->quote($string) . ")]"

- Intl:
  . Added IntlDateFormatter::getIanaID()/intltz_get_iana_id() to
    the IANA identifier from a given timezone.

- MBString:
  . Added mb_trim, mb_ltrim and mb_rtrim functions.
    RFC: https://wiki.php.net/rfc/mb_trim
  . Added mb_ucfirst and mb_lcfirst functions.
    RFC: https://wiki.php.net/rfc/mb_ucfirst

- Opcache:
  . If JIT is enabled, PHP will now exit with a fatal error on startup in case
    of JIT startup initialization issues.

- Sodium:
  . Added the sodium_crypto_aead_aegis128l_*() and sodium_crypto_aead_aegis256l_*()
    functions to support the AEGIS family of authenticated encryption algorithms,
    that was introduced in libsodium 1.0.19.
  . sodium_crypto_aead_aes256gcm_*() functions are now enabled on aarch64 CPUs
    with the ARM cryptographic extensions.

- Standard:
  . Added the http_get_last_response_headers() and
    http_clear_last_response_headers() that allows retrieving the same content
    as the magic $http_response_header variable.

- XSL:
  . Added XSLTProcessor::registerPhpFunctionNS().
    RFC: https://wiki.php.net/rfc/improve_callbacks_dom_and_xsl

========================================
7. New Classes and Interfaces
========================================

- DOM:
  . Implemented DOM HTML5 parsing and serialization.
    RFC: https://wiki.php.net/rfc/domdocument_html5_parser.
    This RFC adds the new DOM namespace along with new classes and
    constant aliases.
    There are two new classes to handle HTML and XML documents:
    DOM\HTMLDocument and DOM\XMLDocument.
    These classes provide a cleaner API to handle HTML and XML documents.
    Furthermore, the DOM\HTMLDocument class implements spec-compliant HTML5
    parsing and serialization.
  . Implemented opt-in ext/dom spec compliance RFC.
    This adds new classes in the DOM namespace that correspond to modern
    equivalents to the old DOM classes in the global namespaces.
    The new classes follow the DOM living spec.
    RFC: https://wiki.php.net/rfc/opt_in_dom_spec_compliance

========================================
8. Removed Extensions and SAPIs
========================================

- IMAP:
  . The IMAP extension has been unbundled and moved to PECL.
    RFC: https://wiki.php.net/rfc/unbundle_imap_pspell_oci8

- PSpell:
  . The pspell extension has been unbundled and moved to PECL.
    RFC: https://wiki.php.net/rfc/unbundle_imap_pspell_oci8

========================================
9. Other Changes to Extensions
========================================

- Curl:
  . The Curl extension now requires at least libcurl 7.61.0.

- Intl:
  . The class constants are typed now.

- Intl:
  . The OpenSSL extension now requires at least OpenSSL 1.1.1.

- PDO:
  . The class constants are typed now.

- Reflection:
  . The class constants are typed now.

- Spl:
  . The class constants are typed now.

- Sqlite:
  . The class constants are typed now.

- XMLReader:
  . The class constants are typed now.

- XSL:
  . The typed properties XSLTProcessor::$cloneDocument and
    XSLTProcessor::$doXInclude are now declared.

========================================
10. New Global Constants
========================================

- Core:
  . PHP_OUTPUT_HANDLER_PROCESSED.

- Intl:
  . The IntlDateFormatter class exposes now the new PATTERN constant
    reflecting udat api's UDAT_PATTERN.
  . The IntlChar class exposes now the new PROPERTY_IDS_UNARY_OPERATOR (new
    IDS binary operator), PROPERTY_ID_COMPAT_MATH_START,
    PROPERTY_ID_COMPAT_MATH_CONTINUE (both for mathematical
    identifier profiling purpose) constants.

- LDAP:
  . LDAP_OPT_X_TLS_PROTOCOL_MAX.
  . LDAP_OPT_X_TLS_PROTOCOL_TLS1_3.

- LibXML:
  . LIBXML_RECOVER.

- OpenSSL:
  . X509_PURPOSE_OCSP_HELPER.
  . X509_PURPOSE_TIMESTAMP_SIGN.

- Standard:
  . PHP_ROUND_CEILING.
  . PHP_ROUND_FLOOR.
  . PHP_ROUND_TOWARD_ZERO.
  . PHP_ROUND_AWAY_FROM_ZERO.

- Sockets:
  . SO_EXCLUSIVEADDRUSE (Windows only).
  . SOCK_CONN_DGRAM (NetBSD only).
  . SOCK_DCCP (NetBSD only).

- Sodium:
  . SODIUM_CRYPTO_AEAD_AEGIS128L_KEYBYTES
  . SODIUM_CRYPTO_AEAD_AEGIS128L_NSECBYTES
  . SODIUM_CRYPTO_AEAD_AEGIS128L_NPUBBYTES
  . SODIUM_CRYPTO_AEAD_AEGIS128L_ABYTES
  . SODIUM_CRYPTO_AEAD_AEGIS256_KEYBYTES
  . SODIUM_CRYPTO_AEAD_AEGIS256_NSECBYTES
  . SODIUM_CRYPTO_AEAD_AEGIS256_NPUBBYTES
  . SODIUM_CRYPTO_AEAD_AEGIS256_ABYTES

- XML:
  . Added XML_OPTION_PARSE_HUGE to allow large inputs in xml_parse and
    xml_parse_into_struct.
    RFC: https://wiki.php.net/rfc/xml_option_parse_huge.

========================================
11. Changes to INI File Handling
========================================

========================================
12. Windows Support
========================================

========================================
13. Other Changes
========================================

========================================
14. Performance Improvements
========================================

* The performance of DOMNode::C14N() is greatly improved for the case without
  an xpath query. This can give a time improvement of easily two order of
  magnitude for documents with tens of thousands of nodes.

* The performance of strspn() and strcspn() is greatly improved.
  They now run in linear time instead of being bounded by quadratic time.

* Improved the performance of strpbrk().

* mb_strcut() is much faster now for UTF-8 and UTF-16 strings.

* Looking up mbstring encoding names is much faster now.

* The performance of converting SJIS-win to unicode is greatly improved.

* get_browser() is much faster now, up to 1.5x - 2.5x for some test cases.

* Improved the performance of MySQLnd quoting.