[Support] Add "override" where appropriate (NFC) (llvm#164190)

Note that "override" makes "virtual" redundant.

Identified with modernize-use-override.

Author: kazutakahirata

llvm/include/llvm/Support/DebugLog.h

@@ -293,7 +293,7 @@ class RAIINewLineStream final : public raw_ostream {
 
 public:
   RAIINewLineStream(raw_ostream &Os) : Os(Os) { SetUnbuffered(); }
-  ~RAIINewLineStream() { Os << '\n'; }
+  ~RAIINewLineStream() override { Os << '\n'; }
   void write_impl(const char *Ptr, size_t Size) final { Os.write(Ptr, Size); }
   uint64_t current_pos() const final { return Os.tell(); }
   RAIINewLineStream &asLvalue() { return *this; }

llvm/include/llvm/Support/ELFAttrParserCompact.h

@@ -49,7 +49,7 @@ class LLVM_ABI ELFCompactAttrParser : public ELFAttributeParser {
   }
 
 public:
-  virtual ~ELFCompactAttrParser() { static_cast<void>(!cursor.takeError()); }
+  ~ELFCompactAttrParser() override { static_cast<void>(!cursor.takeError()); }
   Error integerAttribute(unsigned tag);
   Error stringAttribute(unsigned tag);
 

llvm/include/llvm/Support/ELFAttrParserExtended.h

@@ -36,7 +36,7 @@ class LLVM_ABI ELFExtendedAttrParser : public ELFAttributeParser {
                        const unsigned Tag);
 
 public:
-  virtual ~ELFExtendedAttrParser() { static_cast<void>(!Cursor.takeError()); }
+  ~ELFExtendedAttrParser() override { static_cast<void>(!Cursor.takeError()); }
   Error parse(ArrayRef<uint8_t> Section, llvm::endianness Endian) override;
 
   std::optional<unsigned> getAttributeValue(unsigned Tag) const override;

llvm/include/llvm/Support/FormatAdapters.h

@@ -77,7 +77,7 @@ class ErrorAdapter : public FormatAdapter<Error> {
 public:
   ErrorAdapter(Error &&Item) : FormatAdapter(std::move(Item)) {}
   ErrorAdapter(ErrorAdapter &&) = default;
-  ~ErrorAdapter() { consumeError(std::move(Item)); }
+  ~ErrorAdapter() override { consumeError(std::move(Item)); }
   void format(llvm::raw_ostream &Stream, StringRef Style) override {
     Stream << Item;
   }

llvm/include/llvm/Support/ScopedPrinter.h

@@ -870,7 +870,7 @@ struct DictScope : DelimitedScope {
     W.objectBegin();
   }
 
-  ~DictScope() {
+  ~DictScope() override {
     if (W)
       W->objectEnd();
   }
@@ -889,7 +889,7 @@ struct ListScope : DelimitedScope {
     W.arrayBegin();
   }
 
-  ~ListScope() {
+  ~ListScope() override {
     if (W)
       W->arrayEnd();
   }

llvm/include/llvm/Support/SuffixTreeNode.h

@@ -155,7 +155,7 @@ struct LLVM_ABI SuffixTreeInternalNode : SuffixTreeNode {
       : SuffixTreeNode(NodeKind::ST_Internal, StartIdx), EndIdx(EndIdx),
         Link(Link) {}
 
-  virtual ~SuffixTreeInternalNode() = default;
+  ~SuffixTreeInternalNode() override = default;
 };
 
 // A node representing a suffix.
@@ -189,7 +189,7 @@ struct LLVM_ABI SuffixTreeLeafNode : SuffixTreeNode {
   SuffixTreeLeafNode(unsigned StartIdx, unsigned *EndIdx)
       : SuffixTreeNode(NodeKind::ST_Leaf, StartIdx), EndIdx(EndIdx) {}
 
-  virtual ~SuffixTreeLeafNode() = default;
+  ~SuffixTreeLeafNode() override = default;
 };
 } // namespace llvm
 #endif // LLVM_SUPPORT_SUFFIXTREE_NODE_H

llvm/include/llvm/Support/VirtualFileSystem.h

@@ -268,7 +268,7 @@ class LLVM_ABI FileSystem : public llvm::ThreadSafeRefCountedBase<FileSystem>,
                             public RTTIExtends<FileSystem, RTTIRoot> {
 public:
   static const char ID;
-  virtual ~FileSystem();
+  ~FileSystem() override;
 
   /// Get the status of the entry at \p Path, if one exists.
   virtual llvm::ErrorOr<Status> status(const Twine &Path) = 0;
@@ -495,7 +495,7 @@ class LLVM_ABI ProxyFileSystem
 private:
   IntrusiveRefCntPtr<FileSystem> FS;
 
-  virtual void anchor() override;
+  void anchor() override;
 };
 
 namespace detail {

llvm/include/llvm/Support/VirtualOutputFile.h

@@ -31,7 +31,7 @@ class OutputFileImpl : public RTTIExtends<OutputFileImpl, RTTIRoot> {
 
 public:
   static char ID;
-  virtual ~OutputFileImpl() = default;
+  ~OutputFileImpl() override = default;
 
   virtual Error keep() = 0;
   virtual Error discard() = 0;

llvm/include/llvm/Support/raw_socket_stream.h

@@ -126,7 +126,7 @@ class LLVM_ABI raw_socket_stream : public raw_fd_stream {
 
 public:
   raw_socket_stream(int SocketFD);
-  ~raw_socket_stream();
+  ~raw_socket_stream() override;
 
   /// Create a \p raw_socket_stream connected to the UNIX domain socket at \p
   /// SocketPath.