Add support for PHP 8.5 #[\NoDiscard]

.github/workflows/lint.yml

@@ -135,7 +135,7 @@ jobs:
         uses: "shivammathur/setup-php@v2"
         with:
           coverage: "none"
-          php-version: "8.4"
+          php-version: "8.5"
 
       - name: "Install dependencies"
         run: "composer install --no-interaction --no-progress"

Makefile

@@ -110,6 +110,12 @@ lint:
 		--exclude tests/PHPStan/Rules/Classes/data/enum-cannot-be-attribute.php \
 		--exclude tests/PHPStan/Rules/Classes/data/class-attributes.php \
 		--exclude tests/PHPStan/Rules/Classes/data/enum-attributes.php \
+		--exclude tests/PHPStan/Rules/Cast/data/void-cast.php \
+		--exclude tests/PHPStan/Rules/Properties/data/property-hook-attributes-nodiscard.php \
+		--exclude tests/PHPStan/Rules/Functions/data/arrow-function-typehints-nodiscard.php \
+		--exclude tests/PHPStan/Rules/Functions/data/closure-typehints-nodiscard.php \
+		--exclude tests/PHPStan/Rules/Functions/data/typehints-nodiscard.php \
+		--exclude tests/PHPStan/Rules/Methods/data/typehints-nodiscard.php \
 		src tests
 
 install-paratest:

build/collision-detector.json

@@ -15,6 +15,7 @@
 		"../tests/PHPStan/Rules/Functions/data/define-bug-3349.php",
 		"../tests/PHPStan/Levels/data/stubs/function.php",
 		"../tests/PHPStan/Rules/Properties/data/abstract-final-property-hook-parse-error.php",
-		"../tests/PHPStan/Rules/Properties/data/final-property-hooks.php"
+		"../tests/PHPStan/Rules/Properties/data/final-property-hooks.php",
+		"../tests/PHPStan/Rules/Cast/data/void-cast.php"
     ]
 }

src/Analyser/MutatingScope.php

@@ -1442,6 +1442,16 @@ static function (Node $node, Scope $scope) use ($arrowScope, &$arrowFunctionImpu
 				if (array_key_exists($cacheKey, $cachedTypes)) {
 					$cachedClosureData = $cachedTypes[$cacheKey];
 
+					$mustUseReturnValue = TrinaryLogic::createNo();
+					foreach ($node->attrGroups as $attrGroup) {
+						foreach ($attrGroup->attrs as $attr) {
+							if ($attr->name->toLowerString() === 'nodiscard') {
+								$mustUseReturnValue = TrinaryLogic::createYes();
+								break;
+							}
+						}
+					}
+
 					return new ClosureType(
 						$parameters,
 						$cachedClosureData['returnType'],
@@ -1454,6 +1464,7 @@ static function (Node $node, Scope $scope) use ($arrowScope, &$arrowFunctionImpu
 						invalidateExpressions: $cachedClosureData['invalidateExpressions'],
 						usedVariables: $cachedClosureData['usedVariables'],
 						acceptsNamedArguments: TrinaryLogic::createYes(),
+						mustUseReturnValue: $mustUseReturnValue,
 					);
 				}
 				if (self::$resolveClosureTypeDepth >= 2) {
@@ -1656,6 +1667,16 @@ static function (Node $node, Scope $scope) use ($arrowScope, &$arrowFunctionImpu
 			];
 			$node->setAttribute('phpstanCachedTypes', $cachedTypes);
 
+			$mustUseReturnValue = TrinaryLogic::createNo();
+			foreach ($node->attrGroups as $attrGroup) {
+				foreach ($attrGroup->attrs as $attr) {
+					if ($attr->name->toLowerString() === 'nodiscard') {
+						$mustUseReturnValue = TrinaryLogic::createYes();
+						break;
+					}
+				}
+			}
+
 			return new ClosureType(
 				$parameters,
 				$returnType,
@@ -1668,6 +1689,7 @@ static function (Node $node, Scope $scope) use ($arrowScope, &$arrowFunctionImpu
 				invalidateExpressions: $invalidateExpressions,
 				usedVariables: $usedVariables,
 				acceptsNamedArguments: TrinaryLogic::createYes(),
+				mustUseReturnValue: $mustUseReturnValue,
 			);
 		} elseif ($node instanceof New_) {
 			if ($node->class instanceof Name) {
@@ -2716,10 +2738,12 @@ private function createFirstClassCallable(
 			$throwPoints = [];
 			$impurePoints = [];
 			$acceptsNamedArguments = TrinaryLogic::createYes();
+			$mustUseReturnValue = TrinaryLogic::createMaybe();
 			if ($variant instanceof CallableParametersAcceptor) {
 				$throwPoints = $variant->getThrowPoints();
 				$impurePoints = $variant->getImpurePoints();
 				$acceptsNamedArguments = $variant->acceptsNamedArguments();
+				$mustUseReturnValue = $variant->mustUseReturnValue();
 			} elseif ($function !== null) {
 				$returnTypeForThrow = $variant->getReturnType();
 				$throwType = $function->getThrowType();
@@ -2745,6 +2769,7 @@ private function createFirstClassCallable(
 				}
 
 				$acceptsNamedArguments = $function->acceptsNamedArguments();
+				$mustUseReturnValue = $function->mustUseReturnValue();
 			}
 
 			$parameters = $variant->getParameters();
@@ -2759,6 +2784,7 @@ private function createFirstClassCallable(
 				$throwPoints,
 				$impurePoints,
 				acceptsNamedArguments: $acceptsNamedArguments,
+				mustUseReturnValue: $mustUseReturnValue,
 			);
 		}
 

src/PhpDoc/TypeNodeResolver.php

@@ -1032,7 +1032,7 @@ function (CallableTypeParameterNode $parameterNode) use ($nameScope, &$isVariadi
 				),
 			]);
 		} elseif ($mainType instanceof ClosureType) {
-			$closure = new ClosureType($parameters, $returnType, $isVariadic, $templateTypeMap, templateTags: $templateTags, impurePoints: $mainType->getImpurePoints(), invalidateExpressions: $mainType->getInvalidateExpressions(), usedVariables: $mainType->getUsedVariables(), acceptsNamedArguments: $mainType->acceptsNamedArguments());
+			$closure = new ClosureType($parameters, $returnType, $isVariadic, $templateTypeMap, templateTags: $templateTags, impurePoints: $mainType->getImpurePoints(), invalidateExpressions: $mainType->getInvalidateExpressions(), usedVariables: $mainType->getUsedVariables(), acceptsNamedArguments: $mainType->acceptsNamedArguments(), mustUseReturnValue: $mainType->mustUseReturnValue());
 			if ($closure->isPure()->yes() && $returnType->isVoid()->yes()) {
 				return new ErrorType();
 			}

src/Reflection/Annotations/AnnotationMethodReflection.php

@@ -183,4 +183,9 @@ public function getAttributes(): array
 		return [];
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		return TrinaryLogic::createNo();
+	}
+
 }

src/Reflection/Callables/CallableParametersAcceptor.php

@@ -36,4 +36,11 @@ public function getInvalidateExpressions(): array;
 	 */
 	public function getUsedVariables(): array;
 
+	/**
+	 * Has the #[\NoDiscard] attribute - on PHP 8.5+ if the function's return
+	 * value is unused at runtime a warning is emitted, PHPStan will emit the
+	 * warning during analysis and on older PHP versions too
+	 */
+	public function mustUseReturnValue(): TrinaryLogic;
+
 }

src/Reflection/Callables/FunctionCallableVariant.php

@@ -168,4 +168,9 @@ public function acceptsNamedArguments(): TrinaryLogic
 		return $this->function->acceptsNamedArguments();
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		return $this->function->mustUseReturnValue();
+	}
+
 }

src/Reflection/Dummy/ChangedTypeMethodReflection.php

@@ -172,4 +172,9 @@ public function getAttributes(): array
 		return $this->reflection->getAttributes();
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		return $this->reflection->mustUseReturnValue();
+	}
+
 }

src/Reflection/Dummy/DummyConstructorReflection.php

@@ -157,4 +157,10 @@ public function getAttributes(): array
 		return [];
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		// Align with the getAttributes() returning empty
+		return TrinaryLogic::createNo();
+	}
+
 }

src/Reflection/Dummy/DummyMethodReflection.php

@@ -149,4 +149,10 @@ public function getAttributes(): array
 		return [];
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		// Align with the getAttributes() returning empty
+		return TrinaryLogic::createNo();
+	}
+
 }

src/Reflection/ExtendedCallableFunctionVariant.php

@@ -36,6 +36,7 @@ public function __construct(
 		private array $invalidateExpressions,
 		private array $usedVariables,
 		private TrinaryLogic $acceptsNamedArguments,
+		private TrinaryLogic $mustUseReturnValue,
 	)
 	{
 		parent::__construct(
@@ -80,4 +81,9 @@ public function acceptsNamedArguments(): TrinaryLogic
 		return $this->acceptsNamedArguments;
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		return $this->mustUseReturnValue;
+	}
+
 }

src/Reflection/ExtendedMethodReflection.php

@@ -65,4 +65,11 @@ public function isPure(): TrinaryLogic;
 	 */
 	public function getAttributes(): array;
 
+	/**
+	 * Has the #[\NoDiscard] attribute - on PHP 8.5+ if the function's return
+	 * value is unused at runtime a warning is emitted, PHPStan will emit the
+	 * warning during analysis and on older PHP versions too
+	 */
+	public function mustUseReturnValue(): TrinaryLogic;
+
 }

src/Reflection/FunctionReflection.php

@@ -62,4 +62,11 @@ public function isPure(): TrinaryLogic;
 	 */
 	public function getAttributes(): array;
 
+	/**
+	 * Has the #[\NoDiscard] attribute - on PHP 8.5+ if the function's return
+	 * value is unused at runtime a warning is emitted, PHPStan will emit the
+	 * warning during analysis and on older PHP versions too
+	 */
+	public function mustUseReturnValue(): TrinaryLogic;
+
 }

src/Reflection/GenericParametersAcceptorResolver.php

@@ -128,6 +128,7 @@ public static function resolve(array $argTypes, ParametersAcceptor $parametersAc
 				$originalParametersAcceptor->getInvalidateExpressions(),
 				$originalParametersAcceptor->getUsedVariables(),
 				$originalParametersAcceptor->acceptsNamedArguments(),
+				$originalParametersAcceptor->mustUseReturnValue(),
 			);
 		}
 

src/Reflection/InaccessibleMethod.php

@@ -88,4 +88,9 @@ public function acceptsNamedArguments(): TrinaryLogic
 		return $this->methodReflection->acceptsNamedArguments();
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		return TrinaryLogic::createMaybe();
+	}
+
 }

src/Reflection/Native/NativeFunctionReflection.php

@@ -10,6 +10,7 @@
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Type;
 use function count;
+use function strtolower;
 
 final class NativeFunctionReflection implements FunctionReflection
 {
@@ -150,4 +151,14 @@ public function getAttributes(): array
 		return $this->attributes;
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		foreach ($this->attributes as $attrib) {
+			if (strtolower($attrib->getName()) === 'nodiscard') {
+				return TrinaryLogic::createYes();
+			}
+		}
+		return TrinaryLogic::createNo();
+	}
+
 }

src/Reflection/Native/NativeMethodReflection.php

@@ -227,4 +227,14 @@ public function getAttributes(): array
 		return $this->attributes;
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		foreach ($this->attributes as $attrib) {
+			if (strtolower($attrib->getName()) === 'nodiscard') {
+				return TrinaryLogic::createYes();
+			}
+		}
+		return TrinaryLogic::createNo();
+	}
+
 }

src/Reflection/ParametersAcceptorSelector.php

@@ -639,6 +639,7 @@ public static function combineAcceptors(array $acceptors): ExtendedParametersAcc
 		$invalidateExpressions = [];
 		$usedVariables = [];
 		$acceptsNamedArguments = TrinaryLogic::createNo();
+		$mustUseReturnValue = TrinaryLogic::createMaybe();
 
 		foreach ($acceptors as $acceptor) {
 			$returnTypes[] = $acceptor->getReturnType();
@@ -655,6 +656,7 @@ public static function combineAcceptors(array $acceptors): ExtendedParametersAcc
 				$invalidateExpressions = array_merge($invalidateExpressions, $acceptor->getInvalidateExpressions());
 				$usedVariables = array_merge($usedVariables, $acceptor->getUsedVariables());
 				$acceptsNamedArguments = $acceptsNamedArguments->or($acceptor->acceptsNamedArguments());
+				$mustUseReturnValue = $mustUseReturnValue->or($acceptor->mustUseReturnValue());
 			}
 			$isVariadic = $isVariadic || $acceptor->isVariadic();
 
@@ -761,6 +763,7 @@ public static function combineAcceptors(array $acceptors): ExtendedParametersAcc
 				$invalidateExpressions,
 				$usedVariables,
 				$acceptsNamedArguments,
+				$mustUseReturnValue,
 			);
 		}
 
@@ -797,6 +800,7 @@ private static function wrapAcceptor(ParametersAcceptor $acceptor): ExtendedPara
 				$acceptor->getInvalidateExpressions(),
 				$acceptor->getUsedVariables(),
 				$acceptor->acceptsNamedArguments(),
+				$acceptor->mustUseReturnValue(),
 			);
 		}
 

src/Reflection/Php/ClosureCallMethodReflection.php

@@ -202,4 +202,9 @@ public function getAttributes(): array
 		return $this->nativeMethodReflection->getAttributes();
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		return $this->nativeMethodReflection->mustUseReturnValue();
+	}
+
 }

src/Reflection/Php/EnumCasesMethodReflection.php

@@ -161,4 +161,9 @@ public function getAttributes(): array
 		return [];
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		return TrinaryLogic::createNo();
+	}
+
 }

src/Reflection/Php/ExitFunctionReflection.php

@@ -143,4 +143,9 @@ public function getAttributes(): array
 		return [];
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		return TrinaryLogic::createNo();
+	}
+
 }

src/Reflection/Php/PhpFunctionFromParserNodeReflection.php

@@ -24,6 +24,7 @@
 use function array_reverse;
 use function is_array;
 use function is_string;
+use function strtolower;
 
 /**
  * @api
@@ -338,4 +339,14 @@ public function getAttributes(): array
 		return $this->attributes;
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		foreach ($this->attributes as $attrib) {
+			if (strtolower($attrib->getName()) === 'nodiscard') {
+				return TrinaryLogic::createYes();
+			}
+		}
+		return TrinaryLogic::createNo();
+	}
+
 }

src/Reflection/Php/PhpFunctionReflection.php

@@ -29,6 +29,7 @@
 use function count;
 use function is_array;
 use function is_file;
+use function strtolower;
 
 #[GenerateFactory(interface: FunctionReflectionFactory::class)]
 final class PhpFunctionReflection implements FunctionReflection
@@ -275,4 +276,14 @@ public function getAttributes(): array
 		return $this->attributes;
 	}
 
+	public function mustUseReturnValue(): TrinaryLogic
+	{
+		foreach ($this->attributes as $attrib) {
+			if (strtolower($attrib->getName()) === 'nodiscard') {
+				return TrinaryLogic::createYes();
+			}
+		}
+		return TrinaryLogic::createNo();
+	}
+
 }