404-solution / includes / core / ErrorHandler.php

ErrorHandler.php in 404 Solution 4.3.0, at includes/core/ErrorHandler.php

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1	<?php
2
3
4	if (!defined('ABSPATH')) {
5	exit;
6	}
7
8	require_once __DIR__ . '/../policies/ErrorTypeClassifier.php';
9	require_once __DIR__ . '/../services/ErrorDiagnosticsReporter.php';
10	require_once __DIR__ . '/../services/AdminFatalErrorResponder.php';
11	require_once __DIR__ . '/../services/AjaxFatalErrorResponder.php';
12	require_once __DIR__ . '/../services/FatalErrorProcessor.php';
13
14	/* Functions in this class should only be for plugging into WordPress listeners (filters, actions, etc). */
15
16	class ABJ_404_Solution_ErrorHandler {
17
18	/** Keep a reference to the original error handler so we can use it later.
19	* @var callable\|null
20	*/
21	static $originalErrorHandler = null;
22
23	/**
24	* Reserved memory released during fatal shutdown handling so OOM errors can still render fallback output.
25	*
26	* @var string\|null
27	*/
28	private static $reservedMemory = null;
29
30	/** Setup.
31	* @return void
32	*/
33	static function init(): void {
34	// store the original error handler.
35	self::$originalErrorHandler = set_error_handler(function(int $errno, string $errstr, string $errfile = '', int $errline = 0): bool { return false; });
36	restore_error_handler();
37
38	// set to the user defined error handler
39	set_error_handler("ABJ_404_Solution_ErrorHandler::NormalErrorHandler");
40	if (self::$reservedMemory === null) {
41	// Keep a small memory reserve so shutdown handling can render a fallback page on memory exhaustion.
42	self::$reservedMemory = str_repeat('R', 262144);
43	}
44	register_shutdown_function('ABJ_404_Solution_ErrorHandler::FatalErrorHandler');
45	}
46
47	/** Try to capture PHP errors.
48	* @param int $errno
49	* @param string $errstr
50	* @param string $errfile
51	* @param int $errline
52	* @return boolean
53	*/
54	static function NormalErrorHandler($errno, $errstr, $errfile, $errline) {
55	// Respect PHP's `@` error-suppression operator. Up to PHP 7.x the @
56	// operator zeroed error_reporting() for the duration of the call;
57	// PHP 8.0+ instead leaves error_reporting() non-zero but masks out
58	// the specific level being silenced. A custom handler that ignores
59	// this state still escalates intentionally-suppressed warnings to
60	// error-level logging, defeating the suppression.
61	// Concrete case: @opcache_invalidate() at PluginLogic.php:1036 on
62	// hosts with opcache.restrict_api set produces an E_WARNING. The
63	// legacy `error_reporting() === 0` check matched on PHP 7.x but
64	// not on PHP 8.0+ (where the @ leaves the mask non-zero), so 24
65	// such ERROR entries reached the email reporter in the May 10
66	// debug zip, including 2 from current 4.1.17 sites on PHP 8.3.
67	// The bitwise form covers both eras: on PHP 7.x error_reporting()
68	// is 0 and `& $errno` is 0; on PHP 8.0+ the specific level bit is
69	// cleared and `& $errno` is also 0. Returning false here lets
70	// PHP's default handler honour the suppression.
71	if ((error_reporting() & $errno) === 0) {
72	return false;
73	}
74
75	$abj404logging = abj_service('logging');
76	$f = abj_service('functions');
77	$onlyAWarning = false;
78
79	try {
80	// if the error file does not contain the name of our plugin then we ignore it.
81	$slashPos = $f->strpos(ABJ404_NAME, '/');
82	$pluginFolder = $f->substr(ABJ404_NAME, 0, ($slashPos !== false ? $slashPos : null));
83	if ($f->strpos($errfile, $pluginFolder) === false) {
84	// let the normal error handler handle it.
85
86	// this would display the error for other plugins but show @author user
87	// stacktrace from this plugin.
88	// // try calling the original error handler.
89	// if (is_callable(self::$originalErrorHandler)) {
90	// return call_user_func_array(self::$originalErrorHandler,
91	// array($errno, $errstr, $errfile, $errline));
92	// }
93	return false;
94
95	} else {
96	// for our own plugin errors make sure we see them.
97	if ($GLOBALS['abj404_display_errors']) {
98	error_reporting(E_ALL);
99	ini_set('display_errors', '1');
100	}
101	}
102
103	// PHP emits this warning in two forms: with a "by (output started
104	// at /file:line)" suffix when it can attribute the earlier output,
105	// and without that suffix (bare "...headers already sent") when it
106	// cannot. Match the stable prefix so both forms downgrade to a
107	// warning. The " by" variant alone missed the bare form, which then
108	// reached error level and triggered a feedback report (production
109	// report 104, chasalford.com, PHP 8.4).
110	if ($errno == 2 &&
111	$f->strpos($errstr,
112	"Cannot modify header information - headers already sent") !== false) {
113
114	$onlyAWarning = true;
115	}
116
117	$extraInfo = "(none)";
118	$ctxDebugInfo = abj_service('request_context')->debug_info;
119	if ($ctxDebugInfo !== '') {
120	$extraInfo = stripcslashes(wp_kses_post((string)json_encode($ctxDebugInfo)));
121	}
122	$errmsg = "ABJ404-SOLUTION Normal error handler error: errno: " .
123	wp_kses_post((string)json_encode($errno)) . ", errstr: " . wp_kses_post((string)json_encode($errstr)) .
124	", \nerrfile: " . stripcslashes(wp_kses_post((string)json_encode($errfile))) .
125	", \nerrline: " . wp_kses_post((string)json_encode($errline)) .
126	', \nAdditional info: ' . $extraInfo . ", mbstring: " .
127	(extension_loaded('mbstring') ? 'true' : 'false');
128
129	if ($abj404logging != null) {
130	if ($errno === E_NOTICE) {
131	$serverName = array_key_exists('SERVER_NAME', $_SERVER) ? $_SERVER['SERVER_NAME'] : (array_key_exists('HTTP_HOST', $_SERVER) ? $_SERVER['HTTP_HOST'] : '(not found)');
132	$whitelist = isset($GLOBALS['abj404_whitelist']) && is_array($GLOBALS['abj404_whitelist'])
133	? $GLOBALS['abj404_whitelist'] : array();
134	if (in_array($serverName, $whitelist, true)) {
135	$e = new Exception;
136	$abj404logging->debugMessage($errmsg . ', Trace:' . $e->getTraceAsString());
137	}
138	} elseif ($onlyAWarning) {
139	$abj404logging->debugMessage($errmsg);
140	} else {
141	$abj404logging->errorMessage($errmsg);
142	}
143	} else {
144	echo $errmsg;
145	}
146	} catch (Throwable $ex) {
147	// Last-resort breadcrumb: the inner logging path itself failed,
148	// so we can't go through $abj404logging. Match the pattern used
149	// by AdminRuntimeErrorNotice::reportAdminRuntimeError() and
150	// Ajax_SuggestionCompute::handleShutdown(). Widening from
151	// Exception to Throwable is intentional because Error types are
152	// exactly the case the outer handler exists for.
153	abj404_logPhpFallback(
154	'fatal-handler-fallback',
155	'error handler itself failed (code ' . $ex->getCode() . '): ' . $ex->getMessage()
156	);
157	}
158
159	// show all warnings and errors.
160	if ($GLOBALS['abj404_display_errors']) {
161	error_reporting(E_ALL);
162	ini_set('display_errors', '1');
163	}
164	// let the original error handler handle it.
165	return false;
166	}
167
168	/** @return bool */
169	static function FatalErrorHandler(): bool {
170	$lasterror = error_get_last();
171	return self::processFatalError($lasterror);
172	}
173
174	/**
175	* Release the OOM reserve before fatal fallback rendering.
176	*
177	* @return void
178	*/
179	public static function releaseReservedMemory(): void {
180	self::$reservedMemory = null;
181	}
182
183	/**
184	* Process a fatal error (shutdown handler).
185	* Public for unit tests (allows injecting a fake last error).
186	*
187	* @param array<string, mixed>\|null $lasterror
188	* @return bool
189	*/
190	public static function processFatalError($lasterror): bool {
191	$processor = new ABJ_404_Solution_FatalErrorProcessor();
192	return $processor->process($lasterror);
193	}
194	}
195