RemoveUnusedModuleElements: The start function may be imported (#3884)

Without this fix we can segfault, as it has no body.

Fixes #3879

1 files changed, 1 insertions, 1 deletions

diff --git a/src/passes/RemoveUnusedModuleElements.cpp b/src/passes/RemoveUnusedModuleElements.cpp
index 59d9a2a9b..a26fd5d45 100644
--- a/src/passes/RemoveUnusedModuleElements.cpp
+++ b/src/passes/RemoveUnusedModuleElements.cpp
@@ -150,7 +150,7 @@ struct RemoveUnusedModuleElements : public Pass {
     if (module->start.is()) {
       auto startFunction = module->getFunction(module->start);
       // Can be skipped if the start function is empty.
-      if (startFunction->body->is<Nop>()) {
+      if (!startFunction->imported() && startFunction->body->is<Nop>()) {
         module->start.clear();
       } else {
         roots.emplace_back(ModuleElementKind::Function, module->start);