DI: Disallow uniquable DICompileUnits

Since r241097, `DIBuilder` has only created distinct `DICompileUnit`s.
The backend is liable to start relying on that (if it hasn't already),
so make uniquable `DICompileUnit`s illegal and automatically upgrade old
bitcode.  This is a nice cleanup, since we can remove an unnecessary
`DenseSet` (and the associated uniquing info) from `LLVMContextImpl`.

Almost all the testcases were updated with this script:

    git grep -e '= !DICompileUnit' -l -- test |
    grep -v test/Bitcode |
    xargs sed -i '' -e 's,= !DICompileUnit,= distinct !DICompileUnit,'

I imagine something similar should work for out-of-tree testcases.

llvm-svn: 243885

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/IR/MetadataImpl.h b/llvm/lib/IR/MetadataImpl.h
index 662a50eb1bd..b9137460bd2 100644
--- a/llvm/lib/IR/MetadataImpl.h
+++ b/llvm/lib/IR/MetadataImpl.h
@@ -26,6 +26,19 @@ static T *getUniqued(DenseSet<T *, InfoT> &Store,
   return I == Store.end() ? nullptr : *I;
 }
 
+template <class T> T *MDNode::storeImpl(T *N, StorageType Storage) {
+  switch (Storage) {
+  case Uniqued:
+    llvm_unreachable("Cannot unique without a uniquing-store");
+  case Distinct:
+    N->storeDistinctInContext();
+    break;
+  case Temporary:
+    break;
+  }
+  return N;
+}
+
 template <class T, class StoreT>
 T *MDNode::storeImpl(T *N, StorageType Storage, StoreT &Store) {
   switch (Storage) {