Add an empty key for DebugLoc so that you can store an empty DebugLoc in a

DenseMap.

llvm-svn: 128994

1 files changed, 10 insertions, 2 deletions

diff --git a/llvm/include/llvm/Support/DebugLoc.h b/llvm/include/llvm/Support/DebugLoc.h
index 764591cfede..8d19e300ec2 100644
--- a/llvm/include/llvm/Support/DebugLoc.h
+++ b/llvm/include/llvm/Support/DebugLoc.h
@@ -27,11 +27,19 @@ namespace llvm {
   class DebugLoc {
     friend struct DenseMapInfo<DebugLoc>;
 
+    /// getEmptyKey() - A private constructor that returns an unknown that is
+    /// not equal to the tombstone key or DebugLoc().
+    static DebugLoc getEmptyKey() {
+      DebugLoc DL;
+      DL.LineCol = -1;
+      return DL;
+    }
+
     /// getTombstoneKey() - A private constructor that returns an unknown that
-    /// is distinguishable from the usual one.
+    /// is not equal to the empty key or DebugLoc().
     static DebugLoc getTombstoneKey() {
       DebugLoc DL;
-      DL.LineCol = -1;
+      DL.LineCol = -2;
       return DL;
     }