[SystemZ][z/OS] Add new openFileForReadBinary function, and pass IsText parameter to getBufferForFile (#111723)

This patch adds an IsText parameter to the following getBufferForFile,
getBufferForFileImpl. We introduce a new virtual function
openFileForReadBinary which defaults to openFileForRead except in
RealFileSystem which uses the OF_None flag instead of OF_Text.

The default is set to OF_Text instead of OF_None, this change in value
does not affect any other platforms other than z/OS. Setting this
parameter correctly is required to open files on z/OS in the correct
encoding. The IsText parameter is based on the context of where we open
files, for example, in the ASTReader, HeaderMap requires that files
always be opened in binary even though they might be tagged as text.

1 files changed, 19 insertions, 15 deletions

diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
index 6097b85..2876c29 100644
--- a/clang/lib/Basic/FileManager.cpp
+++ b/clang/lib/Basic/FileManager.cpp
@@ -212,8 +212,10 @@ FileManager::getFile(StringRef Filename, bool openFile, bool CacheFailure) {
   return llvm::errorToErrorCode(Result.takeError());
 }
 
-llvm::Expected<FileEntryRef>
-FileManager::getFileRef(StringRef Filename, bool openFile, bool CacheFailure) {
+llvm::Expected<FileEntryRef> FileManager::getFileRef(StringRef Filename,
+                                                     bool openFile,
+                                                     bool CacheFailure,
+                                                     bool IsText) {
   ++NumFileLookups;
 
   // See if there is already an entry in the map.
@@ -259,7 +261,7 @@ FileManager::getFileRef(StringRef Filename, bool openFile, bool CacheFailure) {
   std::unique_ptr<llvm::vfs::File> F;
   llvm::vfs::Status Status;
   auto statError = getStatValue(InterndFileName, Status, true,
-                                openFile ? &F : nullptr);
+                                openFile ? &F : nullptr, IsText);
   if (statError) {
     // There's no real file at the given path.
     if (CacheFailure)
@@ -531,7 +533,7 @@ void FileManager::fillRealPathName(FileEntry *UFE, llvm::StringRef FileName) {
 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
 FileManager::getBufferForFile(FileEntryRef FE, bool isVolatile,
                               bool RequiresNullTerminator,
-                              std::optional<int64_t> MaybeLimit) {
+                              std::optional<int64_t> MaybeLimit, bool IsText) {
   const FileEntry *Entry = &FE.getFileEntry();
   // If the content is living on the file entry, return a reference to it.
   if (Entry->Content)
@@ -558,21 +560,21 @@ FileManager::getBufferForFile(FileEntryRef FE, bool isVolatile,
 
   // Otherwise, open the file.
   return getBufferForFileImpl(Filename, FileSize, isVolatile,
-                              RequiresNullTerminator);
+                              RequiresNullTerminator, IsText);
 }
 
 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
 FileManager::getBufferForFileImpl(StringRef Filename, int64_t FileSize,
-                                  bool isVolatile,
-                                  bool RequiresNullTerminator) const {
+                                  bool isVolatile, bool RequiresNullTerminator,
+                                  bool IsText) const {
   if (FileSystemOpts.WorkingDir.empty())
     return FS->getBufferForFile(Filename, FileSize, RequiresNullTerminator,
-                                isVolatile);
+                                isVolatile, IsText);
 
   SmallString<128> FilePath(Filename);
   FixupRelativePath(FilePath);
   return FS->getBufferForFile(FilePath, FileSize, RequiresNullTerminator,
-                              isVolatile);
+                              isVolatile, IsText);
 }
 
 /// getStatValue - Get the 'stat' information for the specified path,
@@ -580,20 +582,22 @@ FileManager::getBufferForFileImpl(StringRef Filename, int64_t FileSize,
 /// if the path points to a virtual file or does not exist, or returns
 /// false if it's an existent real file.  If FileDescriptor is NULL,
 /// do directory look-up instead of file look-up.
-std::error_code
-FileManager::getStatValue(StringRef Path, llvm::vfs::Status &Status,
-                          bool isFile, std::unique_ptr<llvm::vfs::File> *F) {
+std::error_code FileManager::getStatValue(StringRef Path,
+                                          llvm::vfs::Status &Status,
+                                          bool isFile,
+                                          std::unique_ptr<llvm::vfs::File> *F,
+                                          bool IsText) {
   // FIXME: FileSystemOpts shouldn't be passed in here, all paths should be
   // absolute!
   if (FileSystemOpts.WorkingDir.empty())
-    return FileSystemStatCache::get(Path, Status, isFile, F,
-                                    StatCache.get(), *FS);
+    return FileSystemStatCache::get(Path, Status, isFile, F, StatCache.get(),
+                                    *FS, IsText);
 
   SmallString<128> FilePath(Path);
   FixupRelativePath(FilePath);
 
   return FileSystemStatCache::get(FilePath.c_str(), Status, isFile, F,
-                                  StatCache.get(), *FS);
+                                  StatCache.get(), *FS, IsText);
 }
 
 std::error_code