From 5e92b256da863b10254c5932b1ff7278bc83f57c Mon Sep 17 00:00:00 2001
From: Robert Konicar <robert.konicar@trailofbits.com>
Date: Thu, 26 Oct 2023 15:08:00 +0200
Subject: [PATCH] cg: Fix triggering of an mlir assertion.

---
 lib/vast/CodeGen/CodeGenFunction.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/vast/CodeGen/CodeGenFunction.cpp b/lib/vast/CodeGen/CodeGenFunction.cpp
index 95bfb553e9..816a40a41c 100644
--- a/lib/vast/CodeGen/CodeGenFunction.cpp
+++ b/lib/vast/CodeGen/CodeGenFunction.cpp
@@ -118,7 +118,10 @@ namespace vast::cg
     operation get_last_effective_operation(auto &block) {
         auto last = &block.back();
         if (auto scope = mlir::dyn_cast< core::ScopeOp >(last)) {
-            return get_last_effective_operation(scope.getBody().back());
+            auto &last_block = scope.getBody().back();
+            // Getting last op of empty block triggers MLIR assert
+            if (!last_block.empty())
+                return get_last_effective_operation(last_block);
         }
 
         return last;