Add implicit throw point for dynamic instantiation of non-final classes without constructors

src/Analyser/ExprHandler/NewHandler.php

@@ -84,6 +84,7 @@ public function processExpr(NodeScopeResolver $nodeScopeResolver, Stmt $stmt, Ex
 		$parametersAcceptor = null;
 		$constructorReflection = null;
 		$classReflection = null;
+		$isDynamic = false;
 		$hasYield = false;
 		$throwPoints = [];
 		$impurePoints = [];
@@ -92,7 +93,7 @@ public function processExpr(NodeScopeResolver $nodeScopeResolver, Stmt $stmt, Ex
 		if ($expr->class instanceof Name) {
 			$className = $scope->resolveName($expr->class);
 
-			[$constructorReflection, $classReflection, $parametersAcceptor, $constructorImpurePoints] = $this->processConstructorReflection($className, $expr, $scope);
+			[$constructorReflection, $classReflection, $parametersAcceptor, $constructorImpurePoints] = $this->processConstructorReflection($className, $expr, $scope, false);
 			$impurePoints = array_merge($impurePoints, $constructorImpurePoints);
 
 			if ($parametersAcceptor !== null) {
@@ -153,6 +154,7 @@ public function processExpr(NodeScopeResolver $nodeScopeResolver, Stmt $stmt, Ex
 				$nodeScopeResolver->processStmtNode($expr->class, $scope, $storage, $nodeCallback, StatementContext::createTopLevel());
 			}
 		} else {
+			$isDynamic = true;
 			$objectClasses = $scope->getType($expr)->getObjectClassNames();
 			if (count($objectClasses) === 1) {
 				$objectExprResult = $nodeScopeResolver->processExprNode($stmt, new New_(new Name($objectClasses[0])), $scope, $storage, new NoopNodeCallback(), $context->enterDeep());
@@ -172,7 +174,7 @@ public function processExpr(NodeScopeResolver $nodeScopeResolver, Stmt $stmt, Ex
 			$throwPoints = array_merge($throwPoints, $additionalThrowPoints);
 
 			if ($className !== null) {
-				[$constructorReflection, $classReflection, $parametersAcceptor, $constructorImpurePoints] = $this->processConstructorReflection($className, $expr, $scope);
+				[$constructorReflection, $classReflection, $parametersAcceptor, $constructorImpurePoints] = $this->processConstructorReflection($className, $expr, $scope, true);
 				$impurePoints = array_merge($impurePoints, $constructorImpurePoints);
 			} else {
 				$impurePoints[] = new ImpurePoint(
@@ -202,7 +204,7 @@ public function processExpr(NodeScopeResolver $nodeScopeResolver, Stmt $stmt, Ex
 			if ($constructorThrowPoint !== null) {
 				$throwPoints[] = $constructorThrowPoint;
 			}
-		} elseif ($classReflection === null) {
+		} elseif ($classReflection === null || ($isDynamic && $constructorReflection === null && !$classReflection->isFinal())) {
 			$throwPoints[] = InternalThrowPoint::createImplicit($scope, $expr);
 		}
 
@@ -218,7 +220,7 @@ public function processExpr(NodeScopeResolver $nodeScopeResolver, Stmt $stmt, Ex
 	/**
 	 * @return array{?MethodReflection, ?ClassReflection, ?ParametersAcceptor, ImpurePoint[]}
 	 */
-	private function processConstructorReflection(string $className, New_ $expr, MutatingScope $scope): array
+	private function processConstructorReflection(string $className, New_ $expr, MutatingScope $scope, bool $isDynamic): array
 	{
 		$constructorReflection = null;
 		$parametersAcceptor = null;
@@ -257,6 +259,14 @@ private function processConstructorReflection(string $className, New_ $expr, Mut
 				'instantiation of unknown class',
 				false,
 			);
+		} elseif ($isDynamic && !$classReflection->isFinal()) {
+			$impurePoints[] = new ImpurePoint(
+				$scope,
+				$expr,
+				'new',
+				sprintf('instantiation of class %s', $classReflection->getDisplayName()),
+				false,
+			);
 		}
 
 		return [$constructorReflection, $classReflection, $parametersAcceptor, $impurePoints];

tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleTest.php

@@ -798,4 +798,22 @@ public function testBug14569(): void
 		$this->analyse([__DIR__ . '/data/bug-14569.php'], []);
 	}
 
+	public function testBug6574(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-6574.php'], [
+			[
+				'Dead catch - Exception is never thrown in the try block.',
+				97,
+			],
+			[
+				'Dead catch - Exception is never thrown in the try block.',
+				106,
+			],
+			[
+				'Dead catch - Exception is never thrown in the try block.',
+				115,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Exceptions/data/bug-4806.php

@@ -12,7 +12,7 @@ final public function __construct()
 	}
 }
 
-class HasNoConstructor
+final class HasNoConstructor
 {
 
 }

tests/PHPStan/Rules/Exceptions/data/bug-6574.php

@@ -0,0 +1,117 @@
+<?php declare(strict_types = 1);
+
+namespace Bug6574;
+
+interface FooInterface
+{
+}
+
+interface BarInterface
+{
+	public function __construct();
+}
+
+abstract class AbstractBaz
+{
+}
+
+abstract class AbstractQux
+{
+	public function __construct()
+	{
+	}
+}
+
+class NonFinalClass
+{
+}
+
+interface ThrowsVoidInterface
+{
+	/** @throws void */
+	public function __construct();
+}
+
+abstract class AbstractThrowsVoid
+{
+	/** @throws void */
+	public function __construct()
+	{
+	}
+}
+
+final class FinalClass
+{
+}
+
+/** @param class-string<FooInterface> $class */
+function interfaceWithoutConstructor(string $class): void
+{
+	try {
+		new $class();
+	} catch (\Exception $e) {
+	}
+}
+
+/** @param class-string<BarInterface> $class */
+function interfaceWithConstructor(string $class): void
+{
+	try {
+		new $class();
+	} catch (\Exception $e) {
+	}
+}
+
+/** @param class-string<AbstractBaz> $class */
+function abstractClassWithoutConstructor(string $class): void
+{
+	try {
+		new $class();
+	} catch (\Exception $e) {
+	}
+}
+
+/** @param class-string<AbstractQux> $class */
+function abstractClassWithConstructor(string $class): void
+{
+	try {
+		new $class();
+	} catch (\Exception $e) {
+	}
+}
+
+/** @param class-string<NonFinalClass> $class */
+function nonFinalClassWithoutConstructor(string $class): void
+{
+	try {
+		new $class();
+	} catch (\Exception $e) {
+	}
+}
+
+/** @param class-string<ThrowsVoidInterface> $class */
+function interfaceWithThrowsVoidConstructor(string $class): void
+{
+	try {
+		new $class();
+	} catch (\Exception $e) { // dead catch - constructor is @throws void
+	}
+}
+
+/** @param class-string<AbstractThrowsVoid> $class */
+function abstractClassWithThrowsVoidConstructor(string $class): void
+{
+	try {
+		new $class();
+	} catch (\Exception $e) { // dead catch - constructor is @throws void
+	}
+}
+
+/** @param class-string<FinalClass> $class */
+function finalClassWithoutConstructor(string $class): void
+{
+	try {
+		new $class();
+	} catch (\Exception $e) { // dead catch - final class with no constructor
+	}
+}

tests/PHPStan/Rules/Pure/PureFunctionRuleTest.php

@@ -225,4 +225,9 @@ public function testBug14557(): void
 		$this->analyse([__DIR__ . '/data/bug-14557-function.php'], []);
 	}
 
+	public function testBug6574(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-6574.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Pure/data/bug-6574.php

@@ -0,0 +1,23 @@
+<?php declare(strict_types = 1);
+
+namespace Bug6574Pure;
+
+interface FooInterface
+{
+}
+
+abstract class AbstractBar
+{
+}
+
+/** @param class-string<FooInterface> $class */
+function interfaceWithoutConstructor(string $class): void
+{
+	new $class();
+}
+
+/** @param class-string<AbstractBar> $class */
+function abstractClassWithoutConstructor(string $class): void
+{
+	new $class();
+}