[llvm][vfs] NFCI: Remove const from VFS::getRealPath()

This is an NFC change split from #68645.

Author: jansvoboda11

llvm/include/llvm/Support/VirtualFileSystem.h

@@ -298,7 +298,7 @@ class FileSystem : public llvm::ThreadSafeRefCountedBase<FileSystem>,
   /// symlinks. For real file system, this uses `llvm::sys::fs::real_path`.
   /// This returns errc::operation_not_permitted if not implemented by subclass.
   virtual std::error_code getRealPath(const Twine &Path,
-                                      SmallVectorImpl<char> &Output) const;
+                                      SmallVectorImpl<char> &Output);
 
   /// Check whether a file exists. Provided for convenience.
   bool exists(const Twine &Path);
@@ -393,7 +393,7 @@ class OverlayFileSystem : public RTTIExtends<OverlayFileSystem, FileSystem> {
   std::error_code setCurrentWorkingDirectory(const Twine &Path) override;
   std::error_code isLocal(const Twine &Path, bool &Result) override;
   std::error_code getRealPath(const Twine &Path,
-                              SmallVectorImpl<char> &Output) const override;
+                              SmallVectorImpl<char> &Output) override;
 
   using iterator = FileSystemList::reverse_iterator;
   using const_iterator = FileSystemList::const_reverse_iterator;
@@ -453,7 +453,7 @@ class ProxyFileSystem : public RTTIExtends<ProxyFileSystem, FileSystem> {
     return FS->setCurrentWorkingDirectory(Path);
   }
   std::error_code getRealPath(const Twine &Path,
-                              SmallVectorImpl<char> &Output) const override {
+                              SmallVectorImpl<char> &Output) override {
     return FS->getRealPath(Path, Output);
   }
   std::error_code isLocal(const Twine &Path, bool &Result) override {
@@ -622,7 +622,7 @@ class InMemoryFileSystem : public RTTIExtends<InMemoryFileSystem, FileSystem> {
   /// This doesn't resolve symlinks as they are not supported in in-memory file
   /// system.
   std::error_code getRealPath(const Twine &Path,
-                              SmallVectorImpl<char> &Output) const override;
+                              SmallVectorImpl<char> &Output) override;
   std::error_code isLocal(const Twine &Path, bool &Result) override;
   std::error_code setCurrentWorkingDirectory(const Twine &Path) override;
 
@@ -1047,7 +1047,7 @@ class RedirectingFileSystem
   ErrorOr<std::unique_ptr<File>> openFileForRead(const Twine &Path) override;
 
   std::error_code getRealPath(const Twine &Path,
-                              SmallVectorImpl<char> &Output) const override;
+                              SmallVectorImpl<char> &Output) override;
 
   llvm::ErrorOr<std::string> getCurrentWorkingDirectory() const override;
 

llvm/lib/Support/FileCollector.cpp

@@ -281,7 +281,7 @@ class FileCollectorFileSystem : public vfs::FileSystem {
   }
 
   std::error_code getRealPath(const Twine &Path,
-                              SmallVectorImpl<char> &Output) const override {
+                              SmallVectorImpl<char> &Output) override {
     auto EC = FS->getRealPath(Path, Output);
     if (!EC) {
       Collector->addFile(Path);

llvm/lib/Support/VirtualFileSystem.cpp

@@ -138,7 +138,7 @@ std::error_code FileSystem::makeAbsolute(SmallVectorImpl<char> &Path) const {
 }
 
 std::error_code FileSystem::getRealPath(const Twine &Path,
-                                        SmallVectorImpl<char> &Output) const {
+                                        SmallVectorImpl<char> &Output) {
   return errc::operation_not_permitted;
 }
 
@@ -275,7 +275,7 @@ class RealFileSystem : public FileSystem {
   std::error_code setCurrentWorkingDirectory(const Twine &Path) override;
   std::error_code isLocal(const Twine &Path, bool &Result) override;
   std::error_code getRealPath(const Twine &Path,
-                              SmallVectorImpl<char> &Output) const override;
+                              SmallVectorImpl<char> &Output) override;
 
 protected:
   void printImpl(raw_ostream &OS, PrintType Type,
@@ -357,9 +357,8 @@ std::error_code RealFileSystem::isLocal(const Twine &Path, bool &Result) {
   return llvm::sys::fs::is_local(adjustPath(Path, Storage), Result);
 }
 
-std::error_code
-RealFileSystem::getRealPath(const Twine &Path,
-                            SmallVectorImpl<char> &Output) const {
+std::error_code RealFileSystem::getRealPath(const Twine &Path,
+                                            SmallVectorImpl<char> &Output) {
   SmallString<256> Storage;
   return llvm::sys::fs::real_path(adjustPath(Path, Storage), Output);
 }
@@ -471,9 +470,8 @@ std::error_code OverlayFileSystem::isLocal(const Twine &Path, bool &Result) {
   return errc::no_such_file_or_directory;
 }
 
-std::error_code
-OverlayFileSystem::getRealPath(const Twine &Path,
-                               SmallVectorImpl<char> &Output) const {
+std::error_code OverlayFileSystem::getRealPath(const Twine &Path,
+                                               SmallVectorImpl<char> &Output) {
   for (const auto &FS : FSList)
     if (FS->exists(Path))
       return FS->getRealPath(Path, Output);
@@ -1157,9 +1155,8 @@ std::error_code InMemoryFileSystem::setCurrentWorkingDirectory(const Twine &P) {
   return {};
 }
 
-std::error_code
-InMemoryFileSystem::getRealPath(const Twine &Path,
-                                SmallVectorImpl<char> &Output) const {
+std::error_code InMemoryFileSystem::getRealPath(const Twine &Path,
+                                                SmallVectorImpl<char> &Output) {
   auto CWD = getCurrentWorkingDirectory();
   if (!CWD || CWD->empty())
     return errc::operation_not_permitted;
@@ -2535,7 +2532,7 @@ RedirectingFileSystem::openFileForRead(const Twine &OriginalPath) {
 
 std::error_code
 RedirectingFileSystem::getRealPath(const Twine &OriginalPath,
-                                   SmallVectorImpl<char> &Output) const {
+                                   SmallVectorImpl<char> &Output) {
   SmallString<256> Path;
   OriginalPath.toVector(Path);
 

llvm/unittests/Support/VirtualFileSystemTest.cpp

@@ -82,7 +82,7 @@ class DummyFileSystem : public vfs::FileSystem {
   }
   // Map any symlink to "/symlink".
   std::error_code getRealPath(const Twine &Path,
-                              SmallVectorImpl<char> &Output) const override {
+                              SmallVectorImpl<char> &Output) override {
     auto I = findEntry(Path);
     if (I == FilesAndDirs.end())
       return make_error_code(llvm::errc::no_such_file_or_directory);