Guard copy of std::function to llvm::function_ref (fix crash)

This is a footgun: assigning a null std::function to a function_ref
does not yield a null function_ref...

diff --git a/mlir/lib/ExecutionEngine/JitRunner.cpp b/mlir/lib/ExecutionEngine/JitRunner.cpp
index 824d8f5..df9ec29 100644 (file)
--- a/mlir/lib/ExecutionEngine/JitRunner.cpp
+++ b/mlir/lib/ExecutionEngine/JitRunner.cpp
@@ -205,7 +205,8 @@ static Error compileAndExecute(Options &options, ModuleOp module,
 
   mlir::ExecutionEngineOptions engineOptions;
   engineOptions.llvmModuleBuilder = config.llvmModuleBuilder;
-  engineOptions.transformer = config.transformer;
+  if (config.transformer)
+    engineOptions.transformer = config.transformer;
   engineOptions.jitCodeGenOptLevel = jitCodeGenOptLevel;
   engineOptions.sharedLibPaths = executionEngineLibs;
   engineOptions.enableObjectCache = true;