From 8c079b91f4405ca7df36c624ad2925c07df9f306 Mon Sep 17 00:00:00 2001
From: Lexy Plt <lexy@elranet.eu>
Date: Wed, 6 May 2026 18:16:53 +0200
Subject: [PATCH 1/2] fix(compiler): ensure there is a variable to mark as
 unreachable

---
 CHANGELOG.md                                        |  4 ++++
 CMakeLists.txt                                      |  2 +-
 src/arkreactor/Compiler/Lowerer/LocalsLocator.cpp   |  3 ++-
 tests/unittests/resources/LangSuite/weird-tests.ark | 10 +++++++++-
 4 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index dee6aaf0..6a9af3cf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Change Log
 
+## [4.5.2] - 2026-05-06
+### Changed
+- fix compiler segfault when there is no variable to mark as unreachable
+
 ## [4.5.1] - 2026-05-05
 ### Added
 - special error message when trying to use a hidden symbol due to importing
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 22f52ada..c88b365a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,7 +5,7 @@ project(ark CXX)
 # ArkScript version (have to manually update it)
 set(ARK_VERSION_MAJOR 4)
 set(ARK_VERSION_MINOR 5)
-set(ARK_VERSION_PATCH 1)
+set(ARK_VERSION_PATCH 2)
 set(ARK_VERSION_PRERELEASE 0)
 
 # determine whether this is a standalone project or included by other projects
diff --git a/src/arkreactor/Compiler/Lowerer/LocalsLocator.cpp b/src/arkreactor/Compiler/Lowerer/LocalsLocator.cpp
index e320fb42..177ae4a1 100644
--- a/src/arkreactor/Compiler/Lowerer/LocalsLocator.cpp
+++ b/src/arkreactor/Compiler/Lowerer/LocalsLocator.cpp
@@ -76,6 +76,7 @@ namespace Ark::internal
 
     void LocalsLocator::markLastLocalAsUnreachable()
     {
-        m_scopes.back().data.back().unreachable = true;
+        if (!m_scopes.back().data.empty())
+            m_scopes.back().data.back().unreachable = true;
     }
 }
diff --git a/tests/unittests/resources/LangSuite/weird-tests.ark b/tests/unittests/resources/LangSuite/weird-tests.ark
index 7ade7061..cc1d9827 100644
--- a/tests/unittests/resources/LangSuite/weird-tests.ark
+++ b/tests/unittests/resources/LangSuite/weird-tests.ark
@@ -110,4 +110,12 @@
       (test:eq res 5) }))
 
     (var_after_cond false)
-    (var_after_cond true) }) })
+    (var_after_cond true) })
+
+  (test:case "no segfault when marking variables as unreachable in the compiler" {
+    (mut n 1)
+    (while (< n 10) {
+      (if (> n 1)
+        ((let F (fun (m) (if m m 1))) n))
+      (set n (+ n 1)) })
+    (test:eq n 10) }) })

From 9dac6627cfb1a935acf7e38b98ef3f48acbe6beb Mon Sep 17 00:00:00 2001
From: Lexy Plt <lexy@elranet.eu>
Date: Wed, 6 May 2026 18:45:29 +0200
Subject: [PATCH 2/2] chore: disable force inlining in fuzzed builds

---
 include/Ark/Utils/Platform.hpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/Ark/Utils/Platform.hpp b/include/Ark/Utils/Platform.hpp
index 1a2a9fa9..6760c8ef 100644
--- a/include/Ark/Utils/Platform.hpp
+++ b/include/Ark/Utils/Platform.hpp
@@ -17,10 +17,12 @@
 #    define ARK_OS_LINUX
 #endif
 
-#if defined(__GNUC__) || defined(__clang__)
-#    define ARK_ALWAYS_INLINE __attribute__((always_inline))
-#elif defined(_MSC_VER) && !defined(__clang__)
-#    define ARK_ALWAYS_INLINE __forceinline
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+#    if defined(__GNUC__) || defined(__clang__)
+#        define ARK_ALWAYS_INLINE __attribute__((always_inline))
+#    elif defined(_MSC_VER) && !defined(__clang__)
+#        define ARK_ALWAYS_INLINE __forceinline
+#    endif
 #else
 #    define ARK_ALWAYS_INLINE
 #endif