Fix missing detection of dead code in closures

src/Analyser/NodeScopeResolver.php

@@ -4690,7 +4690,7 @@
 				array_merge($statementResult->getImpurePoints(), $closureImpurePoints),
 			), $closureScope);
 
-			return new ProcessClosureResult($scope, $statementResult->getThrowPoints(), $statementResult->getImpurePoints(), $invalidateExpressions);
+			return new ProcessClosureResult($scope, $statementResult->getThrowPoints(), $statementResult->getImpurePoints(), $invalidateExpressions, $statementResult->isAlwaysTerminating());
 		}
 
 		$count = 0;
@@ -4736,7 +4736,7 @@
 			array_merge($statementResult->getImpurePoints(), $closureImpurePoints),
 		), $closureScope);
 
-		return new ProcessClosureResult($scope->processClosureScope($closureResultScope, null, $byRefUses), $statementResult->getThrowPoints(), $statementResult->getImpurePoints(), $invalidateExpressions);
+		return new ProcessClosureResult($scope->processClosureScope($closureResultScope, null, $byRefUses), $statementResult->getThrowPoints(), $statementResult->getImpurePoints(), $invalidateExpressions, $statementResult->isAlwaysTerminating());
 	}
 
 	/**
@@ -5174,6 +5174,7 @@
 				if ($callCallbackImmediately) {
 					$throwPoints = array_merge($throwPoints, array_map(static fn (ThrowPoint $throwPoint) => $throwPoint->isExplicit() ? ThrowPoint::createExplicit($scope, $throwPoint->getType(), $arg->value, $throwPoint->canContainAnyThrowable()) : ThrowPoint::createImplicit($scope, $arg->value), $closureResult->getThrowPoints()));
 					$impurePoints = array_merge($impurePoints, $closureResult->getImpurePoints());
+					$isAlwaysTerminating = $isAlwaysTerminating || $closureResult->isAlwaysTerminating();
 				}
 
 				$uses = [];
@@ -6701,7 +6702,7 @@
 
 				return $param->var->name;
 			}, $node->getParams());
 			$resolvedPhpDoc = $this->phpDocInheritanceResolver->resolvePhpDocForMethod(
 				$docComment,
 				$file,
 				$scope->getClassReflection(),
@@ -6723,7 +6724,7 @@
 					if (
 						!$param->var instanceof Variable
 						|| !is_string($param->var->name)
 					) {
 						throw new ShouldNotHappenException();
 					}
 
@@ -6755,7 +6756,7 @@
 			}
 		}
 
 		if ($docComment !== null && $resolvedPhpDoc === null) {
 			$resolvedPhpDoc = $this->fileTypeMapper->getResolvedPhpDoc(
 				$file,
 				$class,
@@ -6775,9 +6776,9 @@
 				}
 				$paramType = $paramTag->getType();
 				if ($scope->isInClass()) {
 					$paramType = $this->transformStaticType($scope->getClassReflection(), $paramType);
 				}
 				$phpDocParameterTypes[$paramName] = $paramType;
 			}
 			foreach ($resolvedPhpDoc->getParamClosureThisTags() as $paramName => $paramClosureThisTag) {
 				if (array_key_exists($paramName, $phpDocClosureThisTypeParameters)) {
@@ -6829,7 +6830,7 @@
 					$changedType = $changedType->getStaticObjectType();
 				}
 				return $traverse($changedType);
 			}
 
 			return $traverse($type);
 		});

src/Analyser/ProcessClosureResult.php

@@ -17,6 +17,7 @@ public function __construct(
 		private array $throwPoints,
 		private array $impurePoints,
 		private array $invalidateExpressions,
+		private bool $isAlwaysTerminating,
 	)
 	{
 	}
@@ -50,4 +51,9 @@ public function getInvalidateExpressions(): array
 		return $this->invalidateExpressions;
 	}
 
+	public function isAlwaysTerminating(): bool
+	{
+		return $this->isAlwaysTerminating;
+	}
+
 }

tests/PHPStan/Analyser/ExpressionResultTest.php

@@ -99,6 +99,18 @@ public static function dataIsAlwaysTerminating(): array
 				'exit() ?? $x;',
 				true,
 			],
+			[
+				'(function() { exit(); })();',
+				true,
+			],
+			[
+				'call_user_func(function() { exit(); });',
+				true,
+			],
+			[
+				'usort($arr, static function($a, $b):int { return $a <=> $b; });',
+				false,
+			],
 			[
 				'var_dump(1+exit());',
 				true,