Fix undefined behavior when compiling in C++14 mode (with sized deletion

enabled): ensure that we do not invoke the sized deallocator for MemoryBuffer
subclasses that have tail-allocated data.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259735 91177308-0d34-0410-b5e6-96231b3b80d8

Author: zygoloid

lib/Support/MemoryBuffer.cpp

@@ -86,6 +86,10 @@ class MemoryBufferMem : public MemoryBuffer {
     init(InputData.begin(), InputData.end(), RequiresNullTerminator);
   }
 
+  /// Disable sized deallocation for MemoryBufferMem, because it has
+  /// tail-allocated data.
+  void operator delete(void *p) { ::operator delete(p); }
+
   const char *getBufferIdentifier() const override {
      // The name is stored after the class itself.
     return reinterpret_cast<const char*>(this + 1);
@@ -213,6 +217,10 @@ class MemoryBufferMMapFile : public MemoryBuffer {
     }
   }
 
+  /// Disable sized deallocation for MemoryBufferMMapFile, because it has
+  /// tail-allocated data.
+  void operator delete(void *p) { ::operator delete(p); }
+
   const char *getBufferIdentifier() const override {
     // The name is stored after the class itself.
     return reinterpret_cast<const char *>(this + 1);