1 files changed, 41 insertions, 7 deletions

diff --git a/include/llvm/Transforms/Utils/ValueMapper.h b/include/llvm/Transforms/Utils/ValueMapper.h
index 047ab818711b..469022f34c56 100644
--- a/include/llvm/Transforms/Utils/ValueMapper.h
+++ b/include/llvm/Transforms/Utils/ValueMapper.h
@@ -38,13 +38,34 @@ namespace llvm {
   /// to materialize Values on demand.
   class ValueMaterializer {
     virtual void anchor(); // Out of line method.
-  public:
-    virtual ~ValueMaterializer() {}
 
-    /// materializeValueFor - The client should implement this method if they
-    /// want to generate a mapped Value on demand. For example, if linking
-    /// lazily.
-    virtual Value *materializeValueFor(Value *V) = 0;
+  protected:
+    ~ValueMaterializer() = default;
+    ValueMaterializer() = default;
+    ValueMaterializer(const ValueMaterializer&) = default;
+    ValueMaterializer &operator=(const ValueMaterializer&) = default;
+
+  public:
+    /// The client should implement this method if they want to generate a
+    /// mapped Value on demand. For example, if linking lazily.
+    virtual Value *materializeDeclFor(Value *V) = 0;
+
+    /// If the data being mapped is recursive, the above function can map
+    /// just the declaration and this is called to compute the initializer.
+    /// It is called after the mapping is recorded, so it doesn't need to worry
+    /// about recursion.
+    virtual void materializeInitFor(GlobalValue *New, GlobalValue *Old);
+
+    /// If the client needs to handle temporary metadata it must implement
+    /// these methods.
+    virtual Metadata *mapTemporaryMetadata(Metadata *MD) { return nullptr; }
+    virtual void replaceTemporaryMetadata(const Metadata *OrigMD,
+                                          Metadata *NewMD) {}
+
+    /// The client should implement this method if some metadata need
+    /// not be mapped, for example DISubprogram metadata for functions not
+    /// linked into the destination module.
+    virtual bool isMetadataNeeded(Metadata *MD) { return true; }
   };
 
   /// RemapFlags - These are flags that the value mapping APIs allow.
@@ -59,7 +80,20 @@ namespace llvm {
     /// RF_IgnoreMissingEntries - If this flag is set, the remapper ignores
     /// entries that are not in the value map.  If it is unset, it aborts if an
     /// operand is asked to be remapped which doesn't exist in the mapping.
-    RF_IgnoreMissingEntries = 2
+    RF_IgnoreMissingEntries = 2,
+
+    /// Instruct the remapper to move distinct metadata instead of duplicating
+    /// it when there are module-level changes.
+    RF_MoveDistinctMDs = 4,
+
+    /// Any global values not in value map are mapped to null instead of
+    /// mapping to self. Illegal if RF_IgnoreMissingEntries is also set.
+    RF_NullMapMissingGlobalValues = 8,
+
+    /// Set when there is still temporary metadata that must be handled,
+    /// such as when we are doing function importing and will materialize
+    /// and link metadata as a postpass.
+    RF_HaveUnmaterializedMetadata = 16,
   };
 
   static inline RemapFlags operator|(RemapFlags LHS, RemapFlags RHS) {