1 files changed, 6 insertions, 5 deletions
diff --git a/llvm/tools/llvm-diff/DifferenceEngine.h b/llvm/tools/llvm-diff/DifferenceEngine.h
index da1b6526a6e2..436a35566360 100644
--- a/llvm/tools/llvm-diff/DifferenceEngine.h
+++ b/llvm/tools/llvm-diff/DifferenceEngine.h
@@ -33,7 +33,8 @@ namespace llvm {
   public:
     /// A RAII object for recording the current context.
     struct Context {
-      Context(DifferenceEngine &Engine, Value *L, Value *R) : Engine(Engine) {
+      Context(DifferenceEngine &Engine, const Value *L, const Value *R)
+          : Engine(Engine) {
         Engine.consumer.enterContext(L, R);
       }
 
@@ -50,7 +51,7 @@ namespace llvm {
     class Oracle {
       virtual void anchor();
     public:
-      virtual bool operator()(Value *L, Value *R) = 0;
+      virtual bool operator()(const Value *L, const Value *R) = 0;
 
     protected:
       virtual ~Oracle() {}
@@ -59,8 +60,8 @@ namespace llvm {
     DifferenceEngine(Consumer &consumer)
       : consumer(consumer), globalValueOracle(nullptr) {}
 
-    void diff(Module *L, Module *R);
-    void diff(Function *L, Function *R);
+    void diff(const Module *L, const Module *R);
+    void diff(const Function *L, const Function *R);
     void log(StringRef text) {
       consumer.log(text);
     }
@@ -78,7 +79,7 @@ namespace llvm {
     }
 
     /// Determines whether two global values are equivalent.
-    bool equivalentAsOperands(GlobalValue *L, GlobalValue *R);
+    bool equivalentAsOperands(const GlobalValue *L, const GlobalValue *R);
 
   private:
     Consumer &consumer;