IR: Don't drop MDNode uniquing on null operands
Now that `LLVMContextImpl` can call `MDNode::dropAllReferences()` to
prevent teardown madness, stop dropping uniquing just because an operand
drops to null.
Part of PR21532.
llvm-svn: 225223
diff --git a/llvm/unittests/IR/MetadataTest.cpp b/llvm/unittests/IR/MetadataTest.cpp
index ccdda1c..ef071b3 100644
--- a/llvm/unittests/IR/MetadataTest.cpp
+++ b/llvm/unittests/IR/MetadataTest.cpp
@@ -202,6 +202,26 @@
EXPECT_EQ(Expected, Actual);
}
+TEST_F(MDNodeTest, NullOperand) {
+ // metadata !{}
+ MDNode *Empty = MDNode::get(Context, None);
+
+ // metadata !{metadata !{}}
+ Metadata *Ops[] = {Empty};
+ MDNode *N = MDNode::get(Context, Ops);
+ ASSERT_EQ(Empty, N->getOperand(0));
+
+ // metadata !{metadata !{}} => metadata !{null}
+ N->replaceOperandWith(0, nullptr);
+ ASSERT_EQ(nullptr, N->getOperand(0));
+
+ // metadata !{null}
+ Ops[0] = nullptr;
+ MDNode *NullOp = MDNode::get(Context, Ops);
+ ASSERT_EQ(nullptr, NullOp->getOperand(0));
+ EXPECT_EQ(N, NullOp);
+}
+
typedef MetadataTest MetadataAsValueTest;
TEST_F(MetadataAsValueTest, MDNode) {