[Recycler] Add asan/msan annotations.

This enables use after free and uninit memory checking for memory
returned by a recycler. SelectionDAG currently relies on the opcode of a
free'd node being ISD::DELETED_NODE, so poke a hole in the asan poison
for SDNode opcodes. This means that we won't find some issues, but only
in SDag.

llvm-svn: 300868

1 files changed, 5 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index ad169d33fd1..523f409e6b2 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -639,12 +639,15 @@ void SelectionDAG::DeallocateNode(SDNode *N) {
   // If we have operands, deallocate them.
   removeOperands(N);
 
+  NodeAllocator.Deallocate(AllNodes.remove(N));
+
   // Set the opcode to DELETED_NODE to help catch bugs when node
   // memory is reallocated.
+  // FIXME: There are places in SDag that have grown a dependency on the opcode
+  // value in the released node.
+  __asan_unpoison_memory_region(&N->NodeType, sizeof(N->NodeType));
   N->NodeType = ISD::DELETED_NODE;
 
-  NodeAllocator.Deallocate(AllNodes.remove(N));
-
   // If any of the SDDbgValue nodes refer to this SDNode, invalidate
   // them and forget about that node.
   DbgInfo->erase(N);