From af4db5fc95f5d846c48e80f4266687a34a2975f4 Mon Sep 17 00:00:00 2001
From: Nick Lewycky <nicholas@mxc.ca>
Date: Wed, 6 Apr 2011 05:36:52 +0000
Subject: [PATCH] Support using DebugLoc's in a DenseMap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128988 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/Support/DebugLoc.h | 20 ++++++++++++++++++++
 lib/VMCore/DebugLoc.cpp         | 24 ++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/include/llvm/Support/DebugLoc.h b/include/llvm/Support/DebugLoc.h
index ccc34461291..764591cfede 100644
--- a/include/llvm/Support/DebugLoc.h
+++ b/include/llvm/Support/DebugLoc.h
@@ -15,6 +15,8 @@
 #ifndef LLVM_SUPPORT_DEBUGLOC_H
 #define LLVM_SUPPORT_DEBUGLOC_H
 
+#include "llvm/ADT/DenseMapInfo.h"
+
 namespace llvm {
   class MDNode;
   class LLVMContext;
@@ -23,6 +25,16 @@ namespace llvm {
   /// and MachineInstr to compactly encode file/line/scope information for an
   /// operation.
   class DebugLoc {
+    friend struct DenseMapInfo<DebugLoc>;
+
+    /// getTombstoneKey() - A private constructor that returns an unknown that
+    /// is distinguishable from the usual one.
+    static DebugLoc getTombstoneKey() {
+      DebugLoc DL;
+      DL.LineCol = -1;
+      return DL;
+    }
+
     /// LineCol - This 32-bit value encodes the line and column number for the
     /// location, encoded as 24-bits for line and 8 bits for col.  A value of 0
     /// for either means unknown.
@@ -75,6 +87,14 @@ namespace llvm {
     }
     bool operator!=(const DebugLoc &DL) const { return !(*this == DL); }
   };
+
+  template <>
+  struct DenseMapInfo<DebugLoc> {
+    static DebugLoc getEmptyKey();
+    static DebugLoc getTombstoneKey();
+    static unsigned getHashValue(const DebugLoc &Key);
+    static bool isEqual(const DebugLoc &LHS, const DebugLoc &RHS);
+  };
 } // end namespace llvm
 
 #endif /* LLVM_DEBUGLOC_H */
diff --git a/lib/VMCore/DebugLoc.cpp b/lib/VMCore/DebugLoc.cpp
index f8b45eed0d5..cb077cb4374 100644
--- a/lib/VMCore/DebugLoc.cpp
+++ b/lib/VMCore/DebugLoc.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Support/DebugLoc.h"
+#include "llvm/ADT/DenseMapInfo.h"
 #include "LLVMContextImpl.h"
 using namespace llvm;
 
@@ -127,6 +128,29 @@ DebugLoc DebugLoc::getFromDILocation(MDNode *N) {
   return get(LineNo, ColNo, Scope, dyn_cast_or_null<MDNode>(N->getOperand(3)));
 }
 
+//===----------------------------------------------------------------------===//
+// DenseMap specialization
+//===----------------------------------------------------------------------===//
+
+DebugLoc DenseMapInfo<DebugLoc>::getEmptyKey() {
+  return DebugLoc();
+}
+
+DebugLoc DenseMapInfo<DebugLoc>::getTombstoneKey() {
+  return DebugLoc::getTombstoneKey();
+}
+
+unsigned DenseMapInfo<DebugLoc>::getHashValue(const DebugLoc &Key) {
+  FoldingSetNodeID ID;
+  ID.AddInteger(Key.LineCol);
+  ID.AddInteger(Key.ScopeIdx);
+  return ID.ComputeHash();
+}
+
+bool DenseMapInfo<DebugLoc>::isEqual(const DebugLoc &LHS, const DebugLoc &RHS) {
+  return LHS == RHS;
+}
+
 //===----------------------------------------------------------------------===//
 // LLVMContextImpl Implementation
 //===----------------------------------------------------------------------===//