Rename variable. add comment.

llvm-svn: 104274

2 files changed, 6 insertions, 3 deletions

diff --git a/llvm/include/llvm/Analysis/DebugInfo.h b/llvm/include/llvm/Analysis/DebugInfo.h
index b69b3babb53..473b127247f 100644
--- a/llvm/include/llvm/Analysis/DebugInfo.h
+++ b/llvm/include/llvm/Analysis/DebugInfo.h
@@ -677,7 +677,7 @@ namespace llvm {
     DIVariable CreateVariable(unsigned Tag, DIDescriptor Context,
                               StringRef Name,
                               DIFile F, unsigned LineNo,
-                              DIType Ty, bool OptimizedBuild = false);
+                              DIType Ty, bool AlwaysPreserve = false);
 
     /// CreateComplexVariable - Create a new descriptor for the specified
     /// variable which has a complex address expression for its address.
diff --git a/llvm/lib/Analysis/DebugInfo.cpp b/llvm/lib/Analysis/DebugInfo.cpp
index 194811be903..a7b6d2b65ee 100644
--- a/llvm/lib/Analysis/DebugInfo.cpp
+++ b/llvm/lib/Analysis/DebugInfo.cpp
@@ -1028,7 +1028,7 @@ DIVariable DIFactory::CreateVariable(unsigned Tag, DIDescriptor Context,
                                      StringRef Name,
                                      DIFile F,
                                      unsigned LineNo,
-                                     DIType Ty, bool OptimizedBuild) {
+                                     DIType Ty, bool AlwaysPreserve) {
   Value *Elts[] = {
     GetTagConstant(Tag),
     Context,
@@ -1038,7 +1038,10 @@ DIVariable DIFactory::CreateVariable(unsigned Tag, DIDescriptor Context,
     Ty,
   };
   MDNode *Node = MDNode::get(VMContext, &Elts[0], 6);
-  if (OptimizedBuild) {
+  if (AlwaysPreserve) {
+    // The optimizer may remove local variable. If there is an interest
+    // to preserve variable info in such situation then stash it in a
+    // named mdnode.
     NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.lv");
     NMD->addOperand(Node);
   }