From ca865fbaa493ff3250db39786c41658037e456ab Mon Sep 17 00:00:00 2001
From: Daniel Jasper <djasper@google.com>
Date: Thu, 12 Oct 2017 13:25:05 +0000
Subject: [PATCH 2/2] Reinstantiate old/bad deduplication logic that was
 removed in r315279.

While this shouldn't be necessary anymore, we have cases where we run
into the assertion below, i.e. cases with two non-fragment entries for the
same variable at different frame indices.

This should be fixed, but for now, we should revert to a version that
does not trigger asserts.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315576 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 90f6f2f..064450f 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -219,6 +219,16 @@ void DbgVariable::addMMIEntry(const DbgVariable &V) {
   assert(!FrameIndexExprs.empty() && "Expected an MMI entry");
   assert(!V.FrameIndexExprs.empty() && "Expected an MMI entry");
 
+  // FIXME: This logic should not be necessary anymore, as we now have proper
+  // deduplication. However, without it, we currently run into the assertion
+  // below, which means that we are likely dealing with broken input, i.e. two
+  // non-fragment entries for the same variable at different frame indices.
+  if (FrameIndexExprs.size()) {
+    auto *Expr = FrameIndexExprs.back().Expr;
+    if (!Expr || !Expr->isFragment())
+      return;
+  }
+
   for (const auto &FIE : V.FrameIndexExprs)
     // Ignore duplicate entries.
     if (llvm::none_of(FrameIndexExprs, [&](const FrameIndexExpr &Other) {
-- 
1.8.3.1