If the Address of a variable is an argument then treat the entire
variable declaration as an argument because we want that address
anyhow for our debug information.

This seems to fix rdar://9965111, at least we have more debug
information than before and from reading the assembly it appears
to be the correct location.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151335 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 667dca1..048fc6f 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4581,11 +4581,13 @@
       N = UnusedArgNodeMap[Address];
     SDDbgValue *SDV;
     if (N.getNode()) {
-      // Parameters are handled specially.
-      bool isParameter =
-        DIVariable(Variable).getTag() == dwarf::DW_TAG_arg_variable;
       if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
         Address = BCI->getOperand(0);
+      // Parameters are handled specially.
+      bool isParameter =
+        (DIVariable(Variable).getTag() == dwarf::DW_TAG_arg_variable ||
+         isa<Argument>(Address));
+
       const AllocaInst *AI = dyn_cast<AllocaInst>(Address);
 
       if (isParameter && !AI) {
@@ -4606,6 +4608,8 @@
       else {
         // Can't do anything with other non-AI cases yet.
         DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
+        DEBUG(dbgs() << "non-AllocaInst issue for Address: \n\t");
+        DEBUG(Address->dump());
         return 0;
       }
       DAG.AddDbgValue(SDV, N.getNode(), isParameter);