From d37f51dabb5de6d26a5886236e726c0ad6407678 Mon Sep 17 00:00:00 2001
From: Richard van Velzen <richard@frank.nl>
Date: Wed, 1 Jun 2022 08:20:15 +0200
Subject: [PATCH] Improve dead code detection after nested function calls with
 conditional never return type

---
 src/Analyser/NodeScopeResolver.php            |  8 +++----
 .../DeadCode/UnreachableStatementRuleTest.php | 11 +++++++++
 .../PHPStan/Rules/DeadCode/data/bug-7188.php  | 23 +++++++++++++++++++
 3 files changed, 37 insertions(+), 5 deletions(-)
 create mode 100644 tests/PHPStan/Rules/DeadCode/data/bug-7188.php

diff --git a/src/Analyser/NodeScopeResolver.php b/src/Analyser/NodeScopeResolver.php
index 1e7941bd5c..a6a8cbb2d1 100644
--- a/src/Analyser/NodeScopeResolver.php
+++ b/src/Analyser/NodeScopeResolver.php
@@ -1661,11 +1661,9 @@ private function findEarlyTerminatingExpr(Expr $expr, Scope $scope): ?Expr
 			return $expr;
 		}
 
-		if ($expr instanceof Expr\CallLike || $expr instanceof Expr\Match_) {
-			$exprType = $scope->getType($expr);
-			if ($exprType instanceof NeverType && $exprType->isExplicit()) {
-				return $expr;
-			}
+		$exprType = $scope->getType($expr);
+		if ($exprType instanceof NeverType && $exprType->isExplicit()) {
+			return $expr;
 		}
 
 		return null;
diff --git a/tests/PHPStan/Rules/DeadCode/UnreachableStatementRuleTest.php b/tests/PHPStan/Rules/DeadCode/UnreachableStatementRuleTest.php
index 32599a1c70..4cf373673f 100644
--- a/tests/PHPStan/Rules/DeadCode/UnreachableStatementRuleTest.php
+++ b/tests/PHPStan/Rules/DeadCode/UnreachableStatementRuleTest.php
@@ -120,4 +120,15 @@ public function testBug4370(): void
 		$this->analyse([__DIR__ . '/data/bug-4370.php'], []);
 	}
 
+	public function testBug7188(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+		$this->analyse([__DIR__ . '/data/bug-7188.php'], [
+			[
+				'Unreachable statement - code above always terminates.',
+				22,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/DeadCode/data/bug-7188.php b/tests/PHPStan/Rules/DeadCode/data/bug-7188.php
new file mode 100644
index 0000000000..dd607b23c6
--- /dev/null
+++ b/tests/PHPStan/Rules/DeadCode/data/bug-7188.php
@@ -0,0 +1,23 @@
+<?php declare(strict_types = 1);
+
+namespace Bug7188;
+
+use Exception;
+
+/**
+ * @param int $x
+ * @return ($x is 0 ? never : float)
+ */
+function inverse($x): float
+{
+	if ($x===0) {
+		throw new Exception('Division durch Null.');
+	}
+
+	return 1/$x;
+}
+
+function () {
+	$result = inverse(0);
+	echo "expect to unreachable\n";
+};