From 686a7bbb245096ce47ae11a79db05e25658fdfa8 Mon Sep 17 00:00:00 2001
From: William Moses <gh@wsmoses.com>
Date: Mon, 18 Dec 2023 11:06:36 -0600
Subject: [PATCH] Better error messages for invalid erasure (#1592)

---
 enzyme/Enzyme/CacheUtility.cpp | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/enzyme/Enzyme/CacheUtility.cpp b/enzyme/Enzyme/CacheUtility.cpp
index a2e6df84e9b9..fd34be6c1146 100644
--- a/enzyme/Enzyme/CacheUtility.cpp
+++ b/enzyme/Enzyme/CacheUtility.cpp
@@ -69,19 +69,19 @@ void CacheUtility::erase(Instruction *I) {
   SE.eraseValueFromMap(I);
 
   if (!I->use_empty()) {
+    std::string str;
+    raw_string_ostream ss(str);
+    ss << "Erased value with a use:\n";
+    ss << *newFunc->getParent() << "\n";
+    ss << *newFunc << "\n";
+    ss << *I << "\n";
     if (CustomErrorHandler) {
-      std::string str;
-      raw_string_ostream ss(str);
-      ss << "Erased value with a use:\n";
-      ss << *newFunc->getParent() << "\n";
-      ss << *newFunc << "\n";
-      ss << *I << "\n";
       CustomErrorHandler(str.c_str(), wrap(I), ErrorType::InternalError,
                          nullptr, nullptr, nullptr);
+    } else {
+      EmitFailure("GetIndexError", I->getDebugLoc(), I, ss.str());
     }
-    llvm::errs() << *newFunc->getParent() << "\n";
-    llvm::errs() << *newFunc << "\n";
-    llvm::errs() << *I << "\n";
+    I->replaceAllUsesWith(UndefValue::get(I->getType()));
   }
   assert(I->use_empty());
   I->eraseFromParent();