From 12ccf6df7ee46478f702049cb2f1c5128ccb69ae Mon Sep 17 00:00:00 2001
From: Julien Ponge <jponge@redhat.com>
Date: Wed, 3 Apr 2024 09:52:32 +0300
Subject: [PATCH] Recompute array index shift for unsafe access in JCTools

Fixes segmentation faults when using mutiny.
---
 extensions/mutiny/runtime/pom.xml               |  5 +++++
 .../quarkus/mutiny/runtime/JCToolsSupport.java  | 17 +++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 extensions/mutiny/runtime/src/main/java/io/quarkus/mutiny/runtime/JCToolsSupport.java

diff --git a/extensions/mutiny/runtime/pom.xml b/extensions/mutiny/runtime/pom.xml
index 4d06ca741a0997..80521e1ff2ea6b 100644
--- a/extensions/mutiny/runtime/pom.xml
+++ b/extensions/mutiny/runtime/pom.xml
@@ -47,6 +47,11 @@
             <artifactId>assertj-core</artifactId>
             <scope>test</scope>
         </dependency>
+
+        <dependency>
+            <groupId>org.graalvm.sdk</groupId>
+            <artifactId>nativeimage</artifactId>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/extensions/mutiny/runtime/src/main/java/io/quarkus/mutiny/runtime/JCToolsSupport.java b/extensions/mutiny/runtime/src/main/java/io/quarkus/mutiny/runtime/JCToolsSupport.java
new file mode 100644
index 00000000000000..b93655bff1e18f
--- /dev/null
+++ b/extensions/mutiny/runtime/src/main/java/io/quarkus/mutiny/runtime/JCToolsSupport.java
@@ -0,0 +1,17 @@
+package io.quarkus.mutiny.runtime;
+
+import com.oracle.svm.core.annotate.Alias;
+import com.oracle.svm.core.annotate.RecomputeFieldValue;
+import com.oracle.svm.core.annotate.TargetClass;
+
+class JCToolsSupport {
+}
+
+// Thanks to https://github.com/DataDog/dd-trace-java/pull/6020
+@TargetClass(className = "org.jctools.util.UnsafeRefArrayAccess")
+final class Target_org_jctools_util_UnsafeRefArrayAccess {
+
+    @Alias
+    @RecomputeFieldValue(kind = RecomputeFieldValue.Kind.ArrayIndexShift, declClass = Object[].class)
+    public static int REF_ELEMENT_SHIFT;
+}
\ No newline at end of file