[Support] Remove unnecessary MemoryBuffer::anchor (where the destructor serves as the key function)

llvm-svn: 338175

llvm/include/llvm/Support/MemoryBuffer.h

@@ -43,7 +43,6 @@ class MemoryBuffer {
   const char *BufferStart; // Start of the buffer.
   const char *BufferEnd;   // End of the buffer.
 
-
 protected:
   MemoryBuffer() = default;
 
@@ -148,9 +147,6 @@ public:
   virtual BufferKind getBufferKind() const = 0;
 
   MemoryBufferRef getMemBufferRef() const;
-
-private:
-  virtual void anchor();
 };
 
 /// This class is an extension of MemoryBuffer, which allows copy-on-write

llvm/include/llvm/Support/SmallVectorMemoryBuffer.h

@@ -49,6 +49,9 @@ public:
     init(this->SV.begin(), this->SV.end(), false);
   }
 
+  // Key function.
+  ~SmallVectorMemoryBuffer() override;
+
   StringRef getBufferIdentifier() const override { return BufferName; }
 
   BufferKind getBufferKind() const override { return MemoryBuffer_Malloc; }
@@ -56,7 +59,6 @@ public:
 private:
   SmallVector<char, 0> SV;
   std::string BufferName;
-  void anchor() override;
 };
 
 } // namespace llvm

llvm/lib/Support/MemoryBuffer.cpp

@@ -533,5 +533,4 @@ MemoryBufferRef MemoryBuffer::getMemBufferRef() const {
   return MemoryBufferRef(Data, Identifier);
 }
 
-void MemoryBuffer::anchor() {}
-void SmallVectorMemoryBuffer::anchor() {}
+SmallVectorMemoryBuffer::~SmallVectorMemoryBuffer() {}