Report dead types even in multi-exception catch

[closes phpstan/phpstan#7312]


Co-authored-by: Jan Nedbal <janedbal@gmail.com>

conf/bleedingEdge.neon

@@ -38,3 +38,4 @@ parameters:
 		genericPrototypeMessage: true
 		stricterFunctionMap: true
 		invalidPhpDocTagLine: true
+		detectDeadTypeInMultiCatch: true

conf/config.neon

@@ -68,6 +68,7 @@ parameters:
 		genericPrototypeMessage: false
 		stricterFunctionMap: false
 		invalidPhpDocTagLine: false
+		detectDeadTypeInMultiCatch: false
 	fileExtensions:
 		- php
 	checkAdvancedIsset: false
@@ -306,6 +307,7 @@ parametersSchema:
 		genericPrototypeMessage: bool()
 		stricterFunctionMap: bool()
 		invalidPhpDocTagLine: bool()
+		detectDeadTypeInMultiCatch: bool()
 	])
 	fileExtensions: listOf(string())
 	checkAdvancedIsset: bool()
@@ -664,6 +666,7 @@ services:
 			earlyTerminatingFunctionCalls: %earlyTerminatingFunctionCalls%
 			implicitThrows: %exceptions.implicitThrows%
 			treatPhpDocTypesAsCertain: %treatPhpDocTypesAsCertain%
+			detectDeadTypeInMultiCatch: %featureToggles.detectDeadTypeInMultiCatch%
 
 	-
 		class: PHPStan\Analyser\ConstantResolver

phpstan-baseline.neon

@@ -261,11 +261,21 @@ parameters:
 
 		-
 			message: "#^Dead catch \\- PHPStan\\\\BetterReflection\\\\Identifier\\\\Exception\\\\InvalidIdentifierName is never thrown in the try block\\.$#"
-			count: 2
+			count: 3
 			path: src/Reflection/BetterReflection/BetterReflectionProvider.php
 
 		-
-			message: "#^Dead catch \\- PHPStan\\\\BetterReflection\\\\NodeCompiler\\\\Exception\\\\UnableToCompileNode\\|PHPStan\\\\BetterReflection\\\\Reflection\\\\Exception\\\\NotAClassReflection\\|PHPStan\\\\BetterReflection\\\\Reflection\\\\Exception\\\\NotAnInterfaceReflection is never thrown in the try block\\.$#"
+			message: "#^Dead catch \\- PHPStan\\\\BetterReflection\\\\NodeCompiler\\\\Exception\\\\UnableToCompileNode is never thrown in the try block\\.$#"
+			count: 1
+			path: src/Reflection/BetterReflection/BetterReflectionProvider.php
+
+		-
+			message: "#^Dead catch \\- PHPStan\\\\BetterReflection\\\\Reflection\\\\Exception\\\\NotAClassReflection is never thrown in the try block\\.$#"
+			count: 1
+			path: src/Reflection/BetterReflection/BetterReflectionProvider.php
+
+		-
+			message: "#^Dead catch \\- PHPStan\\\\BetterReflection\\\\Reflection\\\\Exception\\\\NotAnInterfaceReflection is never thrown in the try block\\.$#"
 			count: 1
 			path: src/Reflection/BetterReflection/BetterReflectionProvider.php
 
@@ -415,6 +425,11 @@ parameters:
 			count: 6
 			path: src/Reflection/InitializerExprTypeResolver.php
 
+		-
+			message: "#^Dead catch \\- PHPStan\\\\BetterReflection\\\\Identifier\\\\Exception\\\\InvalidIdentifierName is never thrown in the try block\\.$#"
+			count: 1
+			path: src/Reflection/SignatureMap/NativeFunctionReflectionProvider.php
+
 		-
 			message: "#^Creating new PHPStan\\\\Php8StubsMap is not covered by backward compatibility promise\\. The class might change in a minor PHPStan version\\.$#"
 			count: 1
@@ -1749,6 +1764,11 @@ parameters:
 			count: 1
 			path: tests/PHPStan/Reflection/SignatureMap/Php8SignatureMapProviderTest.php
 
+		-
+			message: "#^Dead catch \\- OutOfBoundsException is never thrown in the try block\\.$#"
+			count: 1
+			path: tests/PHPStan/Reflection/SignatureMap/SignatureMapParserTest.php
+
 		-
 			message: """
 				#^Instantiation of deprecated class PHPStan\\\\Rules\\\\Arrays\\\\AppendedArrayItemTypeRule\\:

src/Analyser/NodeScopeResolver.php

@@ -156,6 +156,7 @@
 use function array_fill_keys;
 use function array_filter;
 use function array_key_exists;
+use function array_keys;
 use function array_map;
 use function array_merge;
 use function array_pop;
@@ -209,6 +210,7 @@ public function __construct(
 		private readonly array $earlyTerminatingFunctionCalls,
 		private readonly bool $implicitThrows,
 		private readonly bool $treatPhpDocTypesAsCertain,
+		private readonly bool $detectDeadTypeInMultiCatch,
 	)
 	{
 		$earlyTerminatingMethodNames = [];
@@ -1267,48 +1269,92 @@ private function processStmtNode(
 			foreach ($stmt->catches as $catchNode) {
 				$nodeCallback($catchNode, $scope);
 
-				$originalCatchType = TypeCombinator::union(...array_map(static fn (Name $name): Type => new ObjectType($name->toString()), $catchNode->types));
-				$isThrowable = $originalCatchType->isSuperTypeOf(new ObjectType(Throwable::class))->yes();
-				$catchType = TypeCombinator::remove($originalCatchType, $pastCatchTypes);
+				$originalCatchTypes = array_map(static fn (Name $name): Type => new ObjectType($name->toString()), $catchNode->types);
+				$catchTypes = array_map(static fn (Type $type): Type => TypeCombinator::remove($type, $pastCatchTypes), $originalCatchTypes);
+
+				$originalCatchType = TypeCombinator::union(...$originalCatchTypes);
+				$catchType = TypeCombinator::union(...$catchTypes);
 				$pastCatchTypes = TypeCombinator::union($pastCatchTypes, $originalCatchType);
-				$matchingThrowPoints = $isThrowable ? $throwPoints : [];
+
+				$matchingThrowPoints = [];
+				$matchingCatchTypes = array_fill_keys(array_keys($originalCatchTypes), false);
+
+				// throwable matches all
+				foreach ($originalCatchTypes as $catchTypeIndex => $catchTypeItem) {
+					if (!$catchTypeItem->isSuperTypeOf(new ObjectType(Throwable::class))->yes()) {
+						continue;
+					}
+
+					foreach ($throwPoints as $throwPointIndex => $throwPoint) {
+						$matchingThrowPoints[$throwPointIndex] = $throwPoint;
+						$matchingCatchTypes[$catchTypeIndex] = true;
+					}
+				}
 
 				// explicit only
 				if (count($matchingThrowPoints) === 0) {
-					foreach ($throwPoints as $throwPoint) {
-						if (!$throwPoint->isExplicit() || $catchType->isSuperTypeOf($throwPoint->getType())->no()) {
+					foreach ($throwPoints as $throwPointIndex => $throwPoint) {
+						if (!$throwPoint->isExplicit()) {
 							continue;
 						}
 
-						$matchingThrowPoints[] = $throwPoint;
+						foreach ($catchTypes as $catchTypeIndex => $catchTypeItem) {
+							if ($catchTypeItem->isSuperTypeOf($throwPoint->getType())->no()) {
+								continue;
+							}
+
+							$matchingThrowPoints[$throwPointIndex] = $throwPoint;
+							$matchingCatchTypes[$catchTypeIndex] = true;
+						}
 					}
 				}
 
 				// implicit only
 				if (count($matchingThrowPoints) === 0) {
-					foreach ($throwPoints as $throwPoint) {
-						if ($throwPoint->isExplicit() || $catchType->isSuperTypeOf($throwPoint->getType())->no()) {
+					foreach ($throwPoints as $throwPointIndex => $throwPoint) {
+						if ($throwPoint->isExplicit()) {
 							continue;
 						}
 
-						$matchingThrowPoints[] = $throwPoint;
+						foreach ($catchTypes as $catchTypeIndex => $catchTypeItem) {
+							if ($catchTypeItem->isSuperTypeOf($throwPoint->getType())->no()) {
+								continue;
+							}
+
+							$matchingThrowPoints[$throwPointIndex] = $throwPoint;
+							$matchingCatchTypes[$catchTypeIndex] = true;
+						}
 					}
 				}
 
 				// include previously removed throw points
-				if (count($matchingThrowPoints) === 0 && $isThrowable) {
-					foreach ($branchScopeResult->getThrowPoints() as $originalThrowPoint) {
-						if (!$originalThrowPoint->canContainAnyThrowable()) {
-							continue;
-						}
+				if (count($matchingThrowPoints) === 0) {
+					if ($originalCatchType->isSuperTypeOf(new ObjectType(Throwable::class))->yes()) {
+						foreach ($branchScopeResult->getThrowPoints() as $originalThrowPoint) {
+							if (!$originalThrowPoint->canContainAnyThrowable()) {
+								continue;
+							}
 
-						$matchingThrowPoints[] = $originalThrowPoint;
+							$matchingThrowPoints[] = $originalThrowPoint;
+							$matchingCatchTypes = array_fill_keys(array_keys($originalCatchTypes), true);
+						}
 					}
 				}
 
 				// emit error
+				if ($this->detectDeadTypeInMultiCatch) {
+					foreach ($matchingCatchTypes as $catchTypeIndex => $matched) {
+						if ($matched) {
+							continue;
+						}
+						$nodeCallback(new CatchWithUnthrownExceptionNode($catchNode, $catchTypes[$catchTypeIndex], $originalCatchTypes[$catchTypeIndex]), $scope);
+					}
+				}
+
 				if (count($matchingThrowPoints) === 0) {
-					$nodeCallback(new CatchWithUnthrownExceptionNode($catchNode, $catchType, $originalCatchType), $scope);
+					if (!$this->detectDeadTypeInMultiCatch) {
+						$nodeCallback(new CatchWithUnthrownExceptionNode($catchNode, $catchType, $originalCatchType), $scope);
+					}
 					continue;
 				}
 

src/File/FileReader.php

@@ -8,6 +8,9 @@
 class FileReader
 {
 
+	/**
+	 * @throws CouldNotReadFileException
+	 */
 	public static function read(string $fileName): string
 	{
 		$path = $fileName;

src/Testing/RuleTestCase.php

@@ -98,6 +98,7 @@ private function getAnalyser(): Analyser
 				[],
 				true,
 				$this->shouldTreatPhpDocTypesAsCertain(),
+				self::getContainer()->getParameter('featureToggles')['detectDeadTypeInMultiCatch'],
 			);
 			$fileAnalyser = new FileAnalyser(
 				$this->createScopeFactory($reflectionProvider, $typeSpecifier),

src/Testing/TypeInferenceTestCase.php

@@ -65,6 +65,7 @@ public static function processFile(
 			static::getEarlyTerminatingFunctionCalls(),
 			true,
 			self::getContainer()->getParameter('treatPhpDocTypesAsCertain'),
+			self::getContainer()->getParameter('featureToggles')['detectDeadTypeInMultiCatch'],
 		);
 		$resolver->setAnalysedFiles(array_map(static fn (string $file): string => $fileHelper->normalizePath($file), array_merge([$file], static::getAdditionalAnalysedFiles())));
 

tests/PHPStan/Analyser/AnalyserTest.php

@@ -642,6 +642,7 @@ private function createAnalyser(bool $reportUnmatchedIgnoredErrors): Analyser
 			[],
 			true,
 			$this->shouldTreatPhpDocTypesAsCertain(),
+			self::getContainer()->getParameter('featureToggles')['detectDeadTypeInMultiCatch'],
 		);
 		$lexer = new Lexer(['usedAttributes' => ['comments', 'startLine', 'endLine', 'startTokenPos', 'endTokenPos']]);
 		$fileAnalyser = new FileAnalyser(

tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleTest.php

@@ -111,6 +111,36 @@ public function testRule(): void
 		]);
 	}
 
+	public function testMultiCatch(): void
+	{
+		$this->analyse([__DIR__ . '/data/unthrown-exception-multi.php'], [
+			[
+				'Dead catch - LogicException is never thrown in the try block.',
+				12,
+			],
+			[
+				'Dead catch - OverflowException is never thrown in the try block.',
+				36,
+			],
+			[
+				'Dead catch - JsonException is never thrown in the try block.',
+				58,
+			],
+			[
+				'Dead catch - RuntimeException is never thrown in the try block.',
+				120,
+			],
+			[
+				'Dead catch - InvalidArgumentException is already caught above.',
+				145,
+			],
+			[
+				'Dead catch - InvalidArgumentException is already caught above.',
+				156,
+			],
+		]);
+	}
+
 	public function testBug4806(): void
 	{
 		$this->analyse([__DIR__ . '/data/bug-4806.php'], [

tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleWithDisabledMultiCatchTest.php

@@ -0,0 +1,42 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Exceptions;
+
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+use function array_merge;
+
+/**
+ * @extends RuleTestCase<CatchWithUnthrownExceptionRule>
+ */
+class CatchWithUnthrownExceptionRuleWithDisabledMultiCatchTest extends RuleTestCase
+{
+
+	protected function getRule(): Rule
+	{
+		return new CatchWithUnthrownExceptionRule();
+	}
+
+	public static function getAdditionalConfigFiles(): array
+	{
+		return array_merge(
+			parent::getAdditionalConfigFiles(),
+			[__DIR__ . '/disable-detect-multi-catch.neon'],
+		);
+	}
+
+	public function testMultiCatchBackwardCompatible(): void
+	{
+		$this->analyse([__DIR__ . '/data/unthrown-exception-multi.php'], [
+			[
+				'Dead catch - InvalidArgumentException is already caught above.',
+				145,
+			],
+			[
+				'Dead catch - InvalidArgumentException is already caught above.',
+				156,
+			],
+		]);
+	}
+
+}