IRMover: Account for matching types present across modules

Summary:
Due to uniqueing of DICompositeTypes, it's possible for a type from one
module to be loaded into another earlier module without being renamed.
Then when the defining module is being IRMoved, the type can be used as
a Mapping destination before being loaded, such that when it's requested
using TypeMapTy::get() it will fail with an assertion that the type is a
source type when it's actually a type in both the source and
destination modules. Correctly handle that case by allowing a non-opaque
non-literal struct type be present in both modules.

Fix for PR37684.

Reviewers: pcc, tejohnson

Reviewed By: pcc, tejohnson

Subscribers: tobiasvk, mehdi_amini, steven_wu, llvm-commits, kcc

Differential Revision: https://reviews.llvm.org/D47898

llvm-svn: 335145

1 files changed, 14 insertions, 5 deletions

diff --git a/llvm/lib/Linker/IRMover.cpp b/llvm/lib/Linker/IRMover.cpp
index 42081442db7..0416ddd5601 100644
--- a/llvm/lib/Linker/IRMover.cpp
+++ b/llvm/lib/Linker/IRMover.cpp
@@ -241,18 +241,27 @@ Type *TypeMapTy::get(Type *Ty, SmallPtrSet<StructType *, 8> &Visited) {
   // These are types that LLVM itself will unique.
   bool IsUniqued = !isa<StructType>(Ty) || cast<StructType>(Ty)->isLiteral();
 
-#ifndef NDEBUG
   if (!IsUniqued) {
+    StructType *STy = cast<StructType>(Ty);
+    // This is actually a type from the destination module, this can be reached
+    // when this type is loaded in another module, added to DstStructTypesSet,
+    // and then we reach the same type in another module where it has not been
+    // added to MappedTypes. (PR37684)
+    if (STy->getContext().isODRUniquingDebugTypes() && !STy->isOpaque() &&
+        DstStructTypesSet.hasType(STy))
+      return *Entry = STy;
+
+#ifndef NDEBUG
     for (auto &Pair : MappedTypes) {
       assert(!(Pair.first != Ty && Pair.second == Ty) &&
              "mapping to a source type");
     }
-  }
 #endif
 
-  if (!IsUniqued && !Visited.insert(cast<StructType>(Ty)).second) {
-    StructType *DTy = StructType::create(Ty->getContext());
-    return *Entry = DTy;
+    if (!Visited.insert(STy).second) {
+      StructType *DTy = StructType::create(Ty->getContext());
+      return *Entry = DTy;
+    }
   }
 
   // If this is not a recursive type, then just map all of the elements and