Narrow the type for the preg_replace_callback() callable.

resources/functionMap.php

@@ -8838,7 +8838,7 @@
 'preg_match_all' => ['int|false|null', 'pattern'=>'string', 'subject'=>'string', '&w_subpatterns='=>'array', 'flags='=>'int', 'offset='=>'int'],
 'preg_quote' => ['string', 'str'=>'string', 'delim_char='=>'string'],
 'preg_replace' => ['string|array|null', 'regex'=>'string|array', 'replace'=>'string|array', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
-'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
+'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable(array<int|string, string>):string', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
 'preg_replace_callback_array' => ['string|array|null', 'pattern'=>'array<string,callable>', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
 'preg_split' => ['array<int, string>|false', 'pattern'=>'string', 'subject'=>'string', 'limit='=>'?int', 'flags='=>'int'],
 'prev' => ['mixed', '&rw_array_arg'=>'array|object'],

resources/functionMap_php74delta.php

@@ -43,7 +43,7 @@
 		'password_algos' => ['array<int, string>'],
 		'password_hash' => ['string|false', 'password'=>'string', 'algo'=>'string|null', 'options='=>'array'],
 		'password_needs_rehash' => ['bool', 'hash'=>'string', 'algo'=>'string|null', 'options='=>'array'],
-		'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int', 'flags='=>'int'],
+		'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable(array<int|string, string>):string', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int', 'flags='=>'int'],
 		'preg_replace_callback_array' => ['string|array|null', 'pattern'=>'array<string,callable>', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int', 'flags='=>'int'],
 		'sapi_windows_set_ctrl_handler' => ['bool', 'callable'=>'callable(int):void', 'add='=>'bool'],
 		'ReflectionProperty::getType' => ['?ReflectionType'],

tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php

@@ -628,6 +628,28 @@ public function testArrayWalkArrowFunctionCallback(): void
 		]);
 	}
 
+	public function testPregReplaceCallback(): void
+	{
+		$this->analyse([__DIR__ . '/data/preg_replace_callback.php'], [
+			[
+				'Parameter #2 $callback of function preg_replace_callback expects callable(array<int|string, string>): string, Closure(string): string given.',
+				6,
+			],
+			[
+				'Parameter #2 $callback of function preg_replace_callback expects callable(array<int|string, string>): string, Closure(string): string given.',
+				13,
+			],
+			[
+				'Parameter #2 $callback of function preg_replace_callback expects callable(array<int|string, string>): string, Closure(array): void given.',
+				20,
+			],
+			[
+				'Parameter #2 $callback of function preg_replace_callback expects callable(array<int|string, string>): string, Closure(): void given.',
+				25,
+			],
+		]);
+	}
+
 	public function testUasortCallback(): void
 	{
 		$this->analyse([__DIR__ . '/data/uasort.php'], [

tests/PHPStan/Rules/Functions/data/preg_replace_callback.php

@@ -0,0 +1,50 @@
+<?php declare(strict_types = 1);
+
+// Incorrect
+$string = preg_replace_callback(
+	'#pattern#',
+	function(string $string): string {
+		return $string;
+	},
+	'subject'
+);
+$string = preg_replace_callback(
+	'#pattern#',
+	function(string $string) {
+		return $string;
+	},
+	'subject'
+);
+$string = preg_replace_callback(
+	'#pattern#',
+	function(array $matches) {},
+	'subject'
+);
+$string = preg_replace_callback(
+	'#pattern#',
+	function() {},
+	'subject'
+);
+
+// Correct
+$string = preg_replace_callback(
+	'#pattern#',
+	function(array $matches): string {
+		return $matches[0];
+	},
+	'subject'
+);
+$string = preg_replace_callback(
+	'#pattern#',
+	function(array $matches) {
+		return $matches[0];
+	},
+	'subject'
+);
+$string = preg_replace_callback(
+	'#pattern#',
+	function() {
+		return 'Hello';
+	},
+	'subject'
+);