From 08f8f21b91e4a805ea71f48c1b04795a14da0f75 Mon Sep 17 00:00:00 2001
From: Davide Italiano <davide@freebsd.org>
Date: Fri, 8 Apr 2016 00:01:32 +0000
Subject: [PATCH] [IR/Verifier] Fix (yet another) crash.

We need to check that if we reference a retainedType from
DICompileUnit we're actually referencing a DICompositeType.

llvm-svn: 265752
---
 llvm/lib/IR/Verifier.cpp                      | 22 ++++++++++++++--------
 llvm/test/Verifier/dbg-invalid-retaintypes.ll | 10 ++++++++++
 2 files changed, 24 insertions(+), 8 deletions(-)
 create mode 100644 llvm/test/Verifier/dbg-invalid-retaintypes.ll

diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index fc9cc7d..abb0e9b 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -4380,14 +4380,20 @@ void Verifier::verifyTypeRefs() {
 
   // Visit all the compile units again to map the type references.
   SmallDenseMap<const MDString *, const DIType *, 32> TypeRefs;
-  for (auto *MD : CUs->operands())
-    if (auto *CU = dyn_cast<DICompileUnit>(MD))
-      for (DIType *Op : CU->getRetainedTypes())
-        if (auto *T = dyn_cast_or_null<DICompositeType>(Op))
-          if (auto *S = T->getRawIdentifier()) {
-            UnresolvedTypeRefs.erase(S);
-            TypeRefs.insert(std::make_pair(S, T));
-          }
+  for (auto *MD : CUs->operands()) {
+    auto *CU = dyn_cast<DICompileUnit>(MD);
+    if (!CU)
+      continue;
+    auto *Array = CU->getRawRetainedTypes();
+    if (!Array || !isa<MDTuple>(Array))
+      continue;
+    for (DIType *Op : CU->getRetainedTypes())
+      if (auto *T = dyn_cast_or_null<DICompositeType>(Op))
+        if (auto *S = T->getRawIdentifier()) {
+          UnresolvedTypeRefs.erase(S);
+          TypeRefs.insert(std::make_pair(S, T));
+        }
+  }
 
   // Verify debug info intrinsic bit piece expressions.  This needs a second
   // pass through the intructions, since we haven't built TypeRefs yet when
diff --git a/llvm/test/Verifier/dbg-invalid-retaintypes.ll b/llvm/test/Verifier/dbg-invalid-retaintypes.ll
new file mode 100644
index 0000000..fa14ae8
--- /dev/null
+++ b/llvm/test/Verifier/dbg-invalid-retaintypes.ll
@@ -0,0 +1,10 @@
+; RUN: not llvm-as -disable-output <%s 2>&1 | FileCheck %s
+; CHECK:      assembly parsed, but does not verify
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang version 3.0 (trunk 131941)", isOptimized: true, emissionKind: FullDebug, file: !2, retainedTypes: !1)
+!1 = distinct !DISubprogram(name: "main", line: 1, isLocal: false, isDefinition: true, virtualIndex: 6, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 1, scope: !2)
+!2 = !DIFile(filename: "/davide/test", directory: "/")
+!3 = !{i32 1, !"Debug Info Version", i32 3}
-- 
2.7.4