Validate callback signatures for curl_setopt callback options like CURLOPT_PREREQFUNCTION

src/Reflection/ParametersAcceptorSelector.php

@@ -1250,6 +1250,35 @@ private static function getCurlOptValueType(int $curlOpt): ?Type
 			return $shareType;
 		}
 
+		$curlHandleType = PhpVersionStaticAccessor::getInstance()->supportsCurlShareHandle()
+			? new ObjectType('CurlHandle')
+			: new ResourceType();
+
+		// callback options: [parameter types passed to the callback (after the handle), expected return type]
+		$callbackConstants = [
+			'CURLOPT_WRITEFUNCTION' => [[new StringType()], new IntegerType()],
+			'CURLOPT_HEADERFUNCTION' => [[new StringType()], new IntegerType()],
+			'CURLOPT_READFUNCTION' => [[new ResourceType(), new IntegerType()], new StringType()],
+			'CURLOPT_PROGRESSFUNCTION' => [[new IntegerType(), new IntegerType(), new IntegerType(), new IntegerType()], new IntegerType()],
+			'CURLOPT_XFERINFOFUNCTION' => [[new IntegerType(), new IntegerType(), new IntegerType(), new IntegerType()], new IntegerType()],
+			'CURLOPT_PREREQFUNCTION' => [[new StringType(), new StringType(), new IntegerType(), new IntegerType()], new IntegerType()],
+		];
+		foreach ($callbackConstants as $constName => [$paramTypes, $returnType]) {
+			if (defined($constName) && constant($constName) === $curlOpt) {
+				$parameters = [
+					new DummyParameter('handle', $curlHandleType, false, PassedByReference::createNo(), false, null),
+				];
+				foreach ($paramTypes as $i => $paramType) {
+					$parameters[] = new DummyParameter('param' . $i, $paramType, false, PassedByReference::createNo(), false, null);
+				}
+
+				return new UnionType([
+					new CallableType($parameters, $returnType, false),
+					new NullType(),
+				]);
+			}
+		}
+
 		// unknown constant
 		return null;
 	}

tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php

@@ -1440,6 +1440,43 @@ public function testCurlSetOpt(): void
 		]);
 	}
 
+	public function testCurlSetOptCallback(): void
+	{
+		$this->analyse([__DIR__ . '/data/curl_setopt_callback.php'], [
+			[
+				'Parameter #3 $value of function curl_setopt expects (callable(CurlHandle, string): int)|null, Closure(mixed, string): true given.',
+				13,
+			],
+			[
+				'Parameter #3 $value of function curl_setopt expects (callable(CurlHandle, string): int)|null, Closure(mixed, string): true given.',
+				17,
+			],
+			[
+				'Parameter #3 $value of function curl_setopt expects (callable(CurlHandle, resource, int): string)|null, Closure(mixed, mixed, int): 0 given.',
+				21,
+			],
+			[
+				'Parameter #3 $value of function curl_setopt expects (callable(CurlHandle, int, int, int, int): int)|null, Closure(mixed, int, int, int, int): false given.',
+				25,
+			],
+			[
+				'Parameter #3 $value of function curl_setopt expects (callable(CurlHandle, int, int, int, int): int)|null, Closure(mixed, int, int, int, int): \'\' given.',
+				29,
+			],
+		]);
+	}
+
+	#[RequiresPhp('>= 8.4.0')]
+	public function testCurlSetOptPrereqCallback(): void
+	{
+		$this->analyse([__DIR__ . '/data/curl_setopt_prereq.php'], [
+			[
+				'Parameter #3 $value of function curl_setopt expects (callable(CurlHandle, string, string, int, int): int)|null, Closure(mixed, string, string, int, int): true given.',
+				13,
+			],
+		]);
+	}
+
 	public function testCurlSetOptInvalidShare(): void
 	{
 		if (PHP_VERSION_ID < 80000) {
@@ -1478,6 +1515,11 @@ public function testCurlSetOptArray(): void
 				54,
 				'Offset 19913 (bool) does not accept type string.',
 			],
+			[
+				'Parameter #2 $options of function curl_setopt_array expects array{20011: (callable(CurlHandle, string): int)|null}, array{20011: Closure(mixed, string): true} given.',
+				70,
+				'Offset 20011 ((callable(CurlHandle, string): int)|null) does not accept type Closure(mixed, string): true.',
+			],
 
 		]);
 	}

tests/PHPStan/Rules/Functions/data/curl-setopt-array.php

@@ -65,3 +65,12 @@ function doBar($options) {
 	curl_setopt_array($curl, $options);
 }
 
+function callbackOption() {
+	$curl = curl_init();
+	curl_setopt_array($curl, [
+		\CURLOPT_WRITEFUNCTION => function ($ch, string $data): bool { // invalid, must return int
+			return true;
+		},
+	]);
+}
+

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

@@ -0,0 +1,57 @@
+<?php declare(strict_types = 1);
+
+namespace CurlSetOptCallback;
+
+class HelloWorld
+{
+
+	public function invalid(): void
+	{
+		$ch = curl_init();
+
+		// WRITEFUNCTION expects a callback returning int
+		curl_setopt($ch, CURLOPT_WRITEFUNCTION, function ($ch, string $data): bool {
+			return true;
+		});
+		// HEADERFUNCTION expects a callback returning int
+		curl_setopt($ch, CURLOPT_HEADERFUNCTION, function ($ch, string $data): bool {
+			return true;
+		});
+		// READFUNCTION expects a callback returning string
+		curl_setopt($ch, CURLOPT_READFUNCTION, function ($ch, $stream, int $length): int {
+			return 0;
+		});
+		// PROGRESSFUNCTION expects a callback returning int
+		curl_setopt($ch, CURLOPT_PROGRESSFUNCTION, function ($ch, int $a, int $b, int $c, int $d): bool {
+			return false;
+		});
+		// XFERINFOFUNCTION expects a callback returning int
+		curl_setopt($ch, CURLOPT_XFERINFOFUNCTION, function ($ch, int $a, int $b, int $c, int $d): string {
+			return '';
+		});
+	}
+
+	public function valid(): void
+	{
+		$ch = curl_init();
+
+		curl_setopt($ch, CURLOPT_WRITEFUNCTION, function ($ch, string $data): int {
+			return strlen($data);
+		});
+		curl_setopt($ch, CURLOPT_HEADERFUNCTION, function ($ch, string $header): int {
+			return strlen($header);
+		});
+		curl_setopt($ch, CURLOPT_READFUNCTION, function ($ch, $stream, int $length): string {
+			return '';
+		});
+		curl_setopt($ch, CURLOPT_PROGRESSFUNCTION, function ($ch, int $a, int $b, int $c, int $d): int {
+			return 0;
+		});
+		curl_setopt($ch, CURLOPT_XFERINFOFUNCTION, function ($ch, int $a, int $b, int $c, int $d): int {
+			return 0;
+		});
+		// null resets the callback and is allowed
+		curl_setopt($ch, CURLOPT_WRITEFUNCTION, null);
+	}
+
+}

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

@@ -0,0 +1,28 @@
+<?php declare(strict_types = 1);
+
+namespace CurlSetOptPrereq;
+
+class HelloWorld
+{
+
+	public function invalid(): void
+	{
+		$ch = curl_init();
+
+		// CURLOPT_PREREQFUNCTION (PHP 8.4+) expects a callback returning int
+		curl_setopt($ch, CURLOPT_PREREQFUNCTION, function ($ch, string $primaryIp, string $connectIp, int $primaryPort, int $connectPort): bool {
+			return true;
+		});
+	}
+
+	public function valid(): void
+	{
+		$ch = curl_init();
+
+		curl_setopt($ch, CURLOPT_PREREQFUNCTION, function ($ch, string $primaryIp, string $connectIp, int $primaryPort, int $connectPort): int {
+			return CURL_PREREQFUNC_OK;
+		});
+		curl_setopt($ch, CURLOPT_PREREQFUNCTION, null);
+	}
+
+}