Introduce dead-code-detector

Author: janedbal

build/PHPStan/Build/ApiPhpDocEntrypointProvider.php

@@ -0,0 +1,69 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Build;
+
+use PhpParser\Node\Expr\MethodCall;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\Reflection\ParametersAcceptorSelector;
+use PHPStan\Type\Type;
+use PHPStan\Type\TypeCombinator;
+use ShipMonk\PHPStan\DeadCode\Provider\SimpleMethodEntrypointProvider;
+
+final class ApiPhpDocEntrypointProvider extends SimpleMethodEntrypointProvider
+{
+
+	public function isEntrypointMethod(\ReflectionMethod $method): bool
+	{
+		$reflectionClass = $method->getDeclaringClass();
+		$methodName = $method->getName();
+
+		if ($this->isApiClass($reflectionClass)) {
+			return true;
+		}
+
+		do {
+			if ($this->isApiMethod($reflectionClass, $methodName)) {
+				return true;
+			}
+
+			foreach ($reflectionClass->getInterfaces() as $interface) {
+				if ($this->isApiClass($interface)) {
+					return true;
+				}
+
+				if ($this->isApiMethod($interface, $methodName)) {
+					return true;
+				}
+			}
+
+			$reflectionClass = $reflectionClass->getParentClass();
+		} while ($reflectionClass !== false);
+
+		return false;
+    }
+
+	private function isApiClass(\ReflectionClass $reflection): bool
+	{
+		$phpDoc = $reflection->getDocComment();
+		if ($phpDoc !== false && str_contains($phpDoc, '@api')) {
+			return true;
+		}
+
+		return false;
+	}
+
+	private function isApiMethod(\ReflectionClass $reflectionClass, string $methodName): bool
+	{
+		if (!$reflectionClass->hasMethod($methodName)) {
+			return false;
+		}
+
+		$phpDoc = $reflectionClass->getMethod($methodName)->getDocComment();
+		if ($phpDoc !== false && str_contains($phpDoc, '@api')) {
+			return true;
+		}
+
+		return false;
+	}
+}

build/phpstan.neon

@@ -4,6 +4,7 @@ includes:
 	- ../vendor/phpstan/phpstan-phpunit/extension.neon
 	- ../vendor/phpstan/phpstan-phpunit/rules.neon
 	- ../vendor/phpstan/phpstan-strict-rules/rules.neon
+	- ../vendor/shipmonk/dead-code-detector/rules.neon
 	- ../conf/bleedingEdge.neon
 	- ../phpstan-baseline.neon
 	- ../phpstan-baseline.php
@@ -91,6 +92,10 @@ parameters:
 			path: ../src/Diagnose/PHPStanDiagnoseExtension.php
 		- '#^Parameter \#1 \$offsetType of class PHPStan\\Type\\Accessory\\HasOffsetType constructor expects PHPStan\\Type\\Constant\\ConstantIntegerType\|PHPStan\\Type\\Constant\\ConstantStringType#'
 		- '#^Short ternary operator is not allowed#'
+
+		- '#^Unused .*?Factory::create$#' # likely used in DIC
+		- '#^Unused .*?::__construct$#' # disable dead construct analysis, DIC services might not be autowired
+
 	reportStaticMethodSignatures: true
 	tmpDir: %rootDir%/tmp
 	stubFiles:
@@ -111,3 +116,7 @@ services:
 		class: PHPStan\Internal\ContainerDynamicReturnTypeExtension
 		tags:
 			- phpstan.broker.dynamicMethodReturnTypeExtension
+	-
+		class: PHPStan\Build\ApiPhpDocEntrypointProvider
+		tags:
+			- shipmonk.deadCode.entrypointProvider

composer.json

@@ -64,6 +64,7 @@
 		"phpstan/phpstan-strict-rules": "^1.6",
 		"phpunit/phpunit": "^9.5.4",
 		"shipmonk/composer-dependency-analyser": "^1.5",
+		"shipmonk/dead-code-detector": "dev-master",
 		"shipmonk/name-collision-detector": "^2.0"
 	},
 	"config": {