From 033aeffa4b63428934f5000092c582c028cdc53d Mon Sep 17 00:00:00 2001
From: Ondrej Mirtes <ondrej@mirtes.cz>
Date: Fri, 23 Apr 2021 15:41:31 +0200
Subject: [PATCH] yield has implicit throw point

---
 src/Analyser/NodeScopeResolver.php              | 16 ++++++++++++++--
 .../CatchWithUnthrownExceptionRuleTest.php      |  5 +++++
 .../PHPStan/Rules/Exceptions/data/bug-4863.php  | 17 +++++++++++++++++
 3 files changed, 36 insertions(+), 2 deletions(-)
 create mode 100644 tests/PHPStan/Rules/Exceptions/data/bug-4863.php

diff --git a/src/Analyser/NodeScopeResolver.php b/src/Analyser/NodeScopeResolver.php
index 131abbc58a..4a12206fab 100644
--- a/src/Analyser/NodeScopeResolver.php
+++ b/src/Analyser/NodeScopeResolver.php
@@ -2327,7 +2327,6 @@ static function () use ($expr, $rightResult): MutatingScope {
 			|| $expr instanceof Expr\Print_
 			|| $expr instanceof Expr\UnaryMinus
 			|| $expr instanceof Expr\UnaryPlus
-			|| $expr instanceof Expr\YieldFrom
 		) {
 			$result = $this->processExprNode($expr->expr, $scope, $nodeCallback, $context->enterDeep());
 			$throwPoints = $result->getThrowPoints();
@@ -2337,6 +2336,17 @@ static function () use ($expr, $rightResult): MutatingScope {
 				$hasYield = $result->hasYield();
 			}
 
+			$scope = $result->getScope();
+		} elseif ($expr instanceof Expr\YieldFrom) {
+			$result = $this->processExprNode($expr->expr, $scope, $nodeCallback, $context->enterDeep());
+			$throwPoints = $result->getThrowPoints();
+			$throwPoints[] = ThrowPoint::createImplicit($scope);
+			if ($expr instanceof Expr\YieldFrom) {
+				$hasYield = true;
+			} else {
+				$hasYield = $result->hasYield();
+			}
+
 			$scope = $result->getScope();
 		} elseif ($expr instanceof BooleanNot) {
 			$result = $this->processExprNode($expr->expr, $scope, $nodeCallback, $context->enterDeep());
@@ -2518,7 +2528,9 @@ static function () use ($finalScope, $expr): MutatingScope {
 			);
 
 		} elseif ($expr instanceof Expr\Yield_) {
-			$throwPoints = [];
+			$throwPoints = [
+				ThrowPoint::createImplicit($scope),
+			];
 			if ($expr->key !== null) {
 				$keyResult = $this->processExprNode($expr->key, $scope, $nodeCallback, $context->enterDeep());
 				$scope = $keyResult->getScope();
diff --git a/tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleTest.php b/tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleTest.php
index b87445b51d..4bcd58cab2 100644
--- a/tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleTest.php
+++ b/tests/PHPStan/Rules/Exceptions/CatchWithUnthrownExceptionRuleTest.php
@@ -82,4 +82,9 @@ public function testBug4805(): void
 		]);
 	}
 
+	public function testBug4863(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-4863.php'], []);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Exceptions/data/bug-4863.php b/tests/PHPStan/Rules/Exceptions/data/bug-4863.php
new file mode 100644
index 0000000000..724c8a1f03
--- /dev/null
+++ b/tests/PHPStan/Rules/Exceptions/data/bug-4863.php
@@ -0,0 +1,17 @@
+<?php
+
+namespace Bug4863;
+
+class HelloWorld
+{
+	/**
+	 * @return \Generator<string>
+	 */
+	public function generate(): \Generator {
+		try {
+			yield 'test';
+		} catch (\Exception $exception) {
+			echo $exception->getMessage();
+		}
+	}
+}