[Frontend] Remove unused TemporaryFiles

[krasimir]

Summary

OnDiskData.TemporaryFiles is filled only by ASTUnit::addTemporaryFile, which is
dead. Also these files are used nowhere in the frontend nor in libclang.

[krasimir]

• Remove unused method from the header file too

[bkramer]

Kill it :)

include/clang/Frontend/ASTUnit.h

private:
   /// \brief Clear out and deallocate 
   void ClearCachedCompletionResults();
   
   ASTUnit(const ASTUnit &) = delete;
   void operator=(const ASTUnit &) = delete;
   
   explicit ASTUnit(bool MainFileIsAST);
 
-  void CleanTemporaryFiles();
   bool Parse(std::shared_ptr<PCHContainerOperations> PCHContainerOps,
              std::unique_ptr<llvm::MemoryBuffer> OverrideMainBuffer);
 
   struct ComputedPreamble {
     llvm::MemoryBuffer *Buffer;
     std::unique_ptr<llvm::MemoryBuffer> Owner;
     unsigned Size;
     bool PreambleEndsAtStartOfLine;

lib/Frontend/ASTUnit.cpp

~SimpleTimer() {
       }
     }
   };
   
   struct OnDiskData {
     /// \brief The file in which the precompiled preamble is stored.
     std::string PreambleFile;
 
-    /// \brief Temporary files that should be removed when the ASTUnit is
-    /// destroyed.
-    SmallVector<std::string, 4> TemporaryFiles;
-
-    /// \brief Erase temporary files.
-    void CleanTemporaryFiles();
-
     /// \brief Erase the preamble file.
     void CleanPreambleFile();
 
     /// \brief Erase temporary files and the preamble file.
     void Cleanup();
   };
 }
 

 static void setPreambleFile(const ASTUnit *AU, StringRef preambleFile) {
   getOnDiskData(AU).PreambleFile = preambleFile;
 }
 
 static const std::string &getPreambleFile(const ASTUnit *AU) {
   return getOnDiskData(AU).PreambleFile;  
 }
 
-void OnDiskData::CleanTemporaryFiles() {
-  for (StringRef File : TemporaryFiles)
-    llvm::sys::fs::remove(File);
-  TemporaryFiles.clear();
-}
-
 void OnDiskData::CleanPreambleFile() {
   if (!PreambleFile.empty()) {
     llvm::sys::fs::remove(PreambleFile);
     PreambleFile.clear();
   }
 }
 
 void OnDiskData::Cleanup() {
-  CleanTemporaryFiles();
   CleanPreambleFile();
 }
 
 struct ASTUnit::ASTWriterData {
   SmallString<128> Buffer;
   llvm::BitstreamWriter Stream;
   ASTWriter Writer;
 
   ASTWriterData(MemoryBufferCache &PCMCache)
       : Stream(Buffer), Writer(Stream, Buffer, PCMCache, {}) {}
 };
 
 void ASTUnit::clearFileLevelDecls() {
   llvm::DeleteContainerSeconds(FileDecls);
 }
 
-void ASTUnit::CleanTemporaryFiles() {
-  getOnDiskData(this).CleanTemporaryFiles();
-}
-
-void ASTUnit::addTemporaryFile(StringRef TempFile) {
-  getOnDiskData(this).TemporaryFiles.push_back(TempFile);
-}
-
 /// \brief After failing to build a precompiled preamble (due to
 /// errors in the source that occurs in the preamble), the number of
 /// reparses during which we'll skip even trying to precompile the
 /// preamble.
 const unsigned DefaultPreambleRebuildInterval = 5;
 
 /// \brief Tracks the number of ASTUnit objects that are currently active.
 ///
bool ASTUnit::Parse(std::shared_ptr<PCHContainerOperations> PCHContainerOps,
   TheSema.reset();
   Ctx = nullptr;
   PP = nullptr;
   Reader = nullptr;
 
   // Clear out old caches and data.
   TopLevelDecls.clear();
   clearFileLevelDecls();
-  CleanTemporaryFiles();
 
   if (!OverrideMainBuffer) {
     checkAndRemoveNonDriverDiags(StoredDiagnostics);
     TopLevelDeclsInPreamble.clear();
   }
 
   // Create a file manager object to provide access to and cache the filesystem.
   Clang->setFileManager(&getFileManager());