Add llvm.codeview.annotation to implement MSVC __annotation

Summary:
This intrinsic represents a label with a list of associated metadata
strings. It is modelled as reading and writing inaccessible memory so
that it won't be removed as dead code. I think the intention is that the
annotation strings should appear at most once in the debug info, so I
marked it noduplicate. We are allowed to inline code with annotations as
long as we strip the annotation, but that can be done later.

Reviewers: majnemer

Subscribers: eraman, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D36904

llvm-svn: 312569

1 files changed, 7 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index 1d20c5a67b6..7a123e3e92e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -935,10 +935,14 @@ EmitSpecialNode(SDNode *Node, bool IsClone, bool IsCloned,
     EmitCopyFromReg(Node, 0, IsClone, IsCloned, SrcReg, VRBaseMap);
     break;
   }
-  case ISD::EH_LABEL: {
-    MCSymbol *S = cast<EHLabelSDNode>(Node)->getLabel();
+  case ISD::EH_LABEL:
+  case ISD::ANNOTATION_LABEL: {
+    unsigned Opc = (Node->getOpcode() == ISD::EH_LABEL)
+                       ? TargetOpcode::EH_LABEL
+                       : TargetOpcode::ANNOTATION_LABEL;
+    MCSymbol *S = cast<LabelSDNode>(Node)->getLabel();
     BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
-            TII->get(TargetOpcode::EH_LABEL)).addSym(S);
+            TII->get(Opc)).addSym(S);
     break;
   }