Add a method to get a StringMapEntry from a pointer to the string

data it contains (similar to GetStringMapEntryFromValue).  
Patch by Greg Clayton!

llvm-svn: 99371

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/include/llvm/ADT/StringMap.h b/llvm/include/llvm/ADT/StringMap.h
index 86e8546adca..482193859b6 100644
--- a/llvm/include/llvm/ADT/StringMap.h
+++ b/llvm/include/llvm/ADT/StringMap.h
@@ -216,6 +216,14 @@ public:
   static const StringMapEntry &GetStringMapEntryFromValue(const ValueTy &V) {
     return GetStringMapEntryFromValue(const_cast<ValueTy&>(V));
   }
+  
+  /// GetStringMapEntryFromKeyData - Given key data that is known to be embedded
+  /// into a StringMapEntry, return the StringMapEntry itself.
+  static StringMapEntry &GetStringMapEntryFromKeyData(const char *KeyData) {
+    char *Ptr = const_cast<char*>(KeyData) - sizeof(StringMapEntry<ValueTy>);
+    return *reinterpret_cast<StringMapEntry*>(Ptr);
+  }
+  
 
   /// Destroy - Destroy this StringMapEntry, releasing memory back to the
   /// specified allocator.