From 8b19902c5133a422728c3be10acaef8a3ec91213 Mon Sep 17 00:00:00 2001
From: Benjamin Kietzman <bengilgit@gmail.com>
Date: Fri, 25 Oct 2024 11:57:51 -0500
Subject: [PATCH] add assertions that struct alignment is correct

---
 arrow-ipc/regen.sh           | 20 ++++++++++++++++++++
 arrow-ipc/src/gen/File.rs    | 12 ++++++++++++
 arrow-ipc/src/gen/Message.rs | 12 ++++++++++++
 arrow-ipc/src/gen/Schema.rs  | 12 ++++++++++++
 4 files changed, 56 insertions(+)

diff --git a/arrow-ipc/regen.sh b/arrow-ipc/regen.sh
index d828e1027380..e3840d924a0e 100755
--- a/arrow-ipc/regen.sh
+++ b/arrow-ipc/regen.sh
@@ -144,6 +144,26 @@ for f in `ls *.rs`; do
     fi
 done
 
+# Since $FLATC might be unpatched, add assertions that we have correct struct alignment
+function add_struct_alignment_test {
+>>"$1" cat <<'HEREDOC'
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use flatbuffers::Push;
+
+    #[test]
+    fn struct_alignment() {
+        // https://github.com/google/flatbuffers/pull/8398
+        assert_eq!($2::alignment(), PushAlignment::new(8));
+    }
+}
+HEREDOC
+}
+add_struct_alignment_test Schema.rs Buffer
+add_struct_alignment_test Message.rs FieldNode
+add_struct_alignment_test File.rs Block
+
 # Return back to base directory
 popd
 cargo +stable fmt -- src/gen/*
diff --git a/arrow-ipc/src/gen/File.rs b/arrow-ipc/src/gen/File.rs
index 0895a878bcae..9365e6536bee 100644
--- a/arrow-ipc/src/gen/File.rs
+++ b/arrow-ipc/src/gen/File.rs
@@ -494,3 +494,15 @@ pub fn finish_size_prefixed_footer_buffer<'a, 'b, A: flatbuffers::Allocator + 'a
 ) {
     fbb.finish_size_prefixed(root, None);
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use flatbuffers::Push;
+
+    #[test]
+    fn struct_alignment() {
+        // https://github.com/google/flatbuffers/pull/8398
+        assert_eq!(Block::alignment(), PushAlignment::new(8));
+    }
+}
diff --git a/arrow-ipc/src/gen/Message.rs b/arrow-ipc/src/gen/Message.rs
index 81d22c810ab3..54f6a5960d7c 100644
--- a/arrow-ipc/src/gen/Message.rs
+++ b/arrow-ipc/src/gen/Message.rs
@@ -1498,3 +1498,15 @@ pub fn finish_size_prefixed_message_buffer<'a, 'b, A: flatbuffers::Allocator + '
 ) {
     fbb.finish_size_prefixed(root, None);
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use flatbuffers::Push;
+
+    #[test]
+    fn struct_alignment() {
+        // https://github.com/google/flatbuffers/pull/8398
+        assert_eq!(FieldNode::alignment(), PushAlignment::new(8));
+    }
+}
diff --git a/arrow-ipc/src/gen/Schema.rs b/arrow-ipc/src/gen/Schema.rs
index 9ceefca5c5b3..8625268d57ff 100644
--- a/arrow-ipc/src/gen/Schema.rs
+++ b/arrow-ipc/src/gen/Schema.rs
@@ -5602,3 +5602,15 @@ pub fn finish_size_prefixed_schema_buffer<'a, 'b, A: flatbuffers::Allocator + 'a
 ) {
     fbb.finish_size_prefixed(root, None);
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use flatbuffers::Push;
+
+    #[test]
+    fn struct_alignment() {
+        // https://github.com/google/flatbuffers/pull/8398
+        assert_eq!(Buffer::alignment(), PushAlignment::new(8));
+    }
+}