From 4bb78e2cb08fdd0b231ea724626606f5b5a80f25 Mon Sep 17 00:00:00 2001
From: Juneyoung Lee <aqjune@gmail.com>
Date: Sun, 21 Mar 2021 02:14:06 +0900
Subject: [PATCH] [CFLGraph] Fix a crash due to missing handling of freeze

https://reviews.llvm.org/D85534#2636321
---
 lib/Analysis/CFLGraph.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/Analysis/CFLGraph.h b/lib/Analysis/CFLGraph.h
index 21842ed3648..02a13d673f4 100644
--- a/lib/Analysis/CFLGraph.h
+++ b/lib/Analysis/CFLGraph.h
@@ -284,6 +284,13 @@ template <typename CFLAA> class CFLGraphBuilder {
       addAssignEdge(Src, &Inst);
     }
 
+    void visitFreezeInst(FreezeInst &Inst) {
+      // Accessing freeze(ptr) is equivalent to accessing ptr.
+      // The former raises UB iff latter raises UB.
+      auto *Src = Inst.getOperand(0);
+      addAssignEdge(Src, &Inst);
+    }
+
     void visitBinaryOperator(BinaryOperator &Inst) {
       auto *Op1 = Inst.getOperand(0);
       auto *Op2 = Inst.getOperand(1);