From 5bdfa788d65ae5f9259c516f2dff99f39ec65871 Mon Sep 17 00:00:00 2001
From: Alfred Bez <1001186+alfredbez@users.noreply.github.com>
Date: Fri, 16 Oct 2026 13:14:16 +0000
Subject: [PATCH] Fix false-positive unused-variable in declare() {} block

Fixes https://github.com/phpstan/phpstan/issues/15394
---
 src/Analyser/StmtHandler/DeclareHandler.php   |  4 ++-
 .../Rules/DeadCode/UnusedVariableRuleTest.php |  7 +++++
 .../PHPStan/Rules/DeadCode/data/bug-15394.php | 26 +++++++++++++++++++
 turbo-ext/src/DeclareHandler.cpp              |  6 +++--
 4 files changed, 40 insertions(+), 3 deletions(-)
 create mode 100644 tests/PHPStan/Rules/DeadCode/data/bug-15394.php

diff --git a/src/Analyser/StmtHandler/DeclareHandler.php b/src/Analyser/StmtHandler/DeclareHandler.php
index 25518f529e8..ba23ddcaf79 100644
--- a/src/Analyser/StmtHandler/DeclareHandler.php
+++ b/src/Analyser/StmtHandler/DeclareHandler.php
@@ -60,6 +60,7 @@ public function processStmt(
 			$scope = $scope->enterDeclareStrictTypes();
 		}
 
+		$variableFlow = null;
 		if ($stmt->stmts !== null) {
 			$result = $nodeScopeResolver->processStmtNodesInternal($stmt, $stmt->stmts, $scope, $storage, $nodeCallback, $context);
 			$dependencies[] = $result->getDependencies();
@@ -69,9 +70,10 @@ public function processStmt(
 			$impurePoints = $result->getImpurePoints();
 			$alwaysTerminating = $result->isAlwaysTerminating();
 			$exitPoints = $result->getExitPoints();
+			$variableFlow = $result->getVariableFlow();
 		}
 
-		return new InternalStatementResult($scope, hasYield: $hasYield, isAlwaysTerminating: $alwaysTerminating, exitPoints: $exitPoints, throwPoints: $throwPoints, impurePoints: $impurePoints, dependencies: Dependencies::merge(...$dependencies));
+		return new InternalStatementResult($scope, hasYield: $hasYield, isAlwaysTerminating: $alwaysTerminating, exitPoints: $exitPoints, throwPoints: $throwPoints, impurePoints: $impurePoints, variableFlow: $variableFlow, dependencies: Dependencies::merge(...$dependencies));
 	}
 
 }
diff --git a/tests/PHPStan/Rules/DeadCode/UnusedVariableRuleTest.php b/tests/PHPStan/Rules/DeadCode/UnusedVariableRuleTest.php
index 2ceca6991c7..e23f4137eec 100644
--- a/tests/PHPStan/Rules/DeadCode/UnusedVariableRuleTest.php
+++ b/tests/PHPStan/Rules/DeadCode/UnusedVariableRuleTest.php
@@ -459,6 +459,13 @@ public function testBug15225(): void
 		$this->analyse([__DIR__ . '/data/bug-15225.php'], []);
 	}
 
+	public function testBug15394(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-15394.php'], [
+			['Variable $z is never read.', 24],
+		]);
+	}
+
 	public function testFlowMessages(): void
 	{
 		$this->analyse([__DIR__ . '/data/unused-variable-flow-messages.php'], [
diff --git a/tests/PHPStan/Rules/DeadCode/data/bug-15394.php b/tests/PHPStan/Rules/DeadCode/data/bug-15394.php
new file mode 100644
index 00000000000..bd926537066
--- /dev/null
+++ b/tests/PHPStan/Rules/DeadCode/data/bug-15394.php
@@ -0,0 +1,26 @@
+<?php declare(strict_types = 1);
+
+namespace Bug15394;
+
+function test(): void
+{
+	$x = 1;
+	declare(ticks=1) {
+		echo $x;
+	}
+}
+
+function testAssignInsideDeclare(): void
+{
+	declare(ticks=1) {
+		$y = 2;
+	}
+	echo $y;
+}
+
+function testUnusedInsideDeclare(): void
+{
+	declare(ticks=1) {
+		$z = 3;
+	}
+}
diff --git a/turbo-ext/src/DeclareHandler.cpp b/turbo-ext/src/DeclareHandler.cpp
index 1c75e0b03e1..b344cc8c5ca 100644
--- a/turbo-ext/src/DeclareHandler.cpp
+++ b/turbo-ext/src/DeclareHandler.cpp
@@ -121,7 +121,9 @@ class DeclareHandler
 		if (UNEXPECTED(!pt_internal_statement_result_is_always_terminating(result.raw(), alwaysTerminating))) return zv::Val();
 		zv::Val exitPointsHold;
 		zval *exitPoints = pt_internal_statement_result_exit_points(result.raw(), exitPointsHold);
-		if (UNEXPECTED(exitPoints == NULL)) return zv::Val();
+		zv::Val variableFlowHold;
+		zval *variableFlow = pt_internal_statement_result_variable_flow(result.raw(), variableFlowHold);
+		if (UNEXPECTED(variableFlow == NULL)) return zv::Val();
 		{
 			zv::Val hold;
 			zval *resultDependencies = pt_internal_statement_result_dependencies(result.raw(), hold);
@@ -130,7 +132,7 @@ class DeclareHandler
 		}
 		zv::Val mergedDependencies = pt_dependencies_merge_list(dependencies.table());
 		if (UNEXPECTED(mergedDependencies.isUndef())) return zv::Val();
-		return pt_internal_statement_result_new(resultScope, hasYield, alwaysTerminating, exitPoints, throwPoints, impurePoints, NULL, NULL, -1, mergedDependencies.raw());
+		return pt_internal_statement_result_new(resultScope, hasYield, alwaysTerminating, exitPoints, throwPoints, impurePoints, NULL, variableFlow, -1, mergedDependencies.raw());
 	}
 
 	/* the statement-handler entry (Engine.h) */