From b47f27515a6486b6e043afe3288b65617d6fd8d4 Mon Sep 17 00:00:00 2001
From: William Tan <1284324+Ninja3047@users.noreply.github.com>
Date: Wed, 28 Feb 2024 18:37:50 -0500
Subject: [PATCH] return early if we cannot find the entry block in the cfg
 (#408)

---
 lib/Lifters/FunctionLifter.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/Lifters/FunctionLifter.cpp b/lib/Lifters/FunctionLifter.cpp
index f6ffd2d1..216bd1de 100644
--- a/lib/Lifters/FunctionLifter.cpp
+++ b/lib/Lifters/FunctionLifter.cpp
@@ -409,6 +409,13 @@ llvm::Function *FunctionLifter::LiftFunction(const FunctionDecl &decl) {
     return nullptr;
   }
 
+  // Function has no valid instructions.
+  auto &cfg = decl.cfg;
+  if (cfg.find(decl.entry_uid) == cfg.end()) {
+    LOG(ERROR) << "Function missing entry block " << std::hex << decl.address;
+    return nullptr;
+  }
+
   // This is our higher-level function, i.e. it presents itself more like
   // a function compiled from C/C++, rather than being a three-argument Remill
   // function. In this function, we will stack-allocate a `State` structure,