[SystemZ][z/OS] Propagate IsText parameter to open text files as text (#107906)

This patch adds an IsText parameter to the following functions
openFileForRead, getBufferForFile, getBufferForFileImpl and determines
whether a file is text by querying the file tag on z/OS. 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.

10 files changed, 36 insertions, 24 deletions

diff --git a/clang/include/clang/Basic/FileManager.h b/clang/include/clang/Basic/FileManager.h
index 527bbef..67a69fb 100644
--- a/clang/include/clang/Basic/FileManager.h
+++ b/clang/include/clang/Basic/FileManager.h
@@ -286,21 +286,21 @@ public:
   /// MemoryBuffer if successful, otherwise returning null.
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBufferForFile(FileEntryRef Entry, bool isVolatile = false,
-                   bool RequiresNullTerminator = true,
+                   bool RequiresNullTerminator = true, bool IsText = true,
                    std::optional<int64_t> MaybeLimit = std::nullopt);
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBufferForFile(StringRef Filename, bool isVolatile = false,
-                   bool RequiresNullTerminator = true,
+                   bool RequiresNullTerminator = true, bool IsText = true,
                    std::optional<int64_t> MaybeLimit = std::nullopt) const {
     return getBufferForFileImpl(Filename,
                                 /*FileSize=*/(MaybeLimit ? *MaybeLimit : -1),
-                                isVolatile, RequiresNullTerminator);
+                                isVolatile, RequiresNullTerminator, IsText);
   }
 
 private:
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
   getBufferForFileImpl(StringRef Filename, int64_t FileSize, bool isVolatile,
-                       bool RequiresNullTerminator) const;
+                       bool RequiresNullTerminator, bool IsText) const;
 
   DirectoryEntry *&getRealDirEntry(const llvm::vfs::Status &Status);
 
diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
index d12814e..635fdd0e 100644
--- a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
+++ b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
@@ -346,7 +346,7 @@ public:
 
   llvm::ErrorOr<llvm::vfs::Status> status(const Twine &Path) override;
   llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-  openFileForRead(const Twine &Path) override;
+  openFileForRead(const Twine &Path, bool IsText = true) override;
 
   std::error_code getRealPath(const Twine &Path,
                               SmallVectorImpl<char> &Output) override;
diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
index 6097b85..27075ce 100644
--- a/clang/lib/Basic/FileManager.cpp
+++ b/clang/lib/Basic/FileManager.cpp
@@ -530,7 +530,7 @@ void FileManager::fillRealPathName(FileEntry *UFE, llvm::StringRef FileName) {
 
 llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>>
 FileManager::getBufferForFile(FileEntryRef FE, bool isVolatile,
-                              bool RequiresNullTerminator,
+                              bool RequiresNullTerminator, bool IsText,
                               std::optional<int64_t> MaybeLimit) {
   const FileEntry *Entry = &FE.getFileEntry();
   // If the content is living on the file entry, return a reference to it.
@@ -558,21 +558,21 @@ 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,
diff --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp
index 65a8a72..fe3aff7 100644
--- a/clang/lib/Basic/SourceManager.cpp
+++ b/clang/lib/Basic/SourceManager.cpp
@@ -121,8 +121,18 @@ ContentCache::getBufferOrNone(DiagnosticsEngine &Diag, FileManager &FM,
   // Start with the assumption that the buffer is invalid to simplify early
   // return paths.
   IsBufferInvalid = true;
-
-  auto BufferOrError = FM.getBufferForFile(*ContentsEntry, IsFileVolatile);
+  bool IsText = false;
+
+#ifdef __MVS__
+  // If the file is tagged with a text ccsid, it may require autoconversion.
+  llvm::ErrorOr<bool> IsFileText =
+      llvm::iszOSTextFile(ContentsEntry->getName().data());
+  if (IsFileText)
+    IsText = *IsFileText;
+#endif
+
+  auto BufferOrError = FM.getBufferForFile(
+      *ContentsEntry, IsFileVolatile, /*RequiresNullTerminator=*/true, IsText);
 
   // If we were unable to open the file, then we are in an inconsistent
   // situation where the content cache referenced a file which no longer
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 7efcc81..ad0551e 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -5317,7 +5317,8 @@ std::string ASTReader::getOriginalSourceFile(
     const PCHContainerReader &PCHContainerRdr, DiagnosticsEngine &Diags) {
   // Open the AST file.
   auto Buffer = FileMgr.getBufferForFile(ASTFileName, /*IsVolatile=*/false,
-                                         /*RequiresNullTerminator=*/false);
+                                         /*RequiresNullTerminator=*/false,
+                                         /*IsText=*/true);
   if (!Buffer) {
     Diags.Report(diag::err_fe_unable_to_read_pch_file)
         << ASTFileName << Buffer.getError().message();
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
index 4d738e4..7d6239a 100644
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
@@ -353,12 +353,13 @@ DepScanFile::create(EntryRef Entry) {
 }
 
 llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-DependencyScanningWorkerFilesystem::openFileForRead(const Twine &Path) {
+DependencyScanningWorkerFilesystem::openFileForRead(const Twine &Path,
+                                                    bool IsText) {
   SmallString<256> OwnedFilename;
   StringRef Filename = Path.toStringRef(OwnedFilename);
 
   if (shouldBypass(Filename))
-    return getUnderlyingFS().openFileForRead(Path);
+    return getUnderlyingFS().openFileForRead(Path, IsText);
 
   llvm::ErrorOr<EntryRef> Result = getOrCreateFileSystemEntry(Filename);
   if (!Result)
diff --git a/clang/unittests/Driver/DistroTest.cpp b/clang/unittests/Driver/DistroTest.cpp
index 43efc0dd..4c13b8b 100644
--- a/clang/unittests/Driver/DistroTest.cpp
+++ b/clang/unittests/Driver/DistroTest.cpp
@@ -352,9 +352,9 @@ TEST(DistroTest, DetectWindowsAndCrossCompile) {
     }
 
     llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-    openFileForRead(const llvm::Twine &Path) override {
+    openFileForRead(const llvm::Twine &Path, bool IsText = true) override {
       ++Count;
-      return llvm::vfs::ProxyFileSystem::openFileForRead(Path);
+      return llvm::vfs::ProxyFileSystem::openFileForRead(Path, IsText);
     }
 
     unsigned Count{};
diff --git a/clang/unittests/Driver/ToolChainTest.cpp b/clang/unittests/Driver/ToolChainTest.cpp
index a9b5f3c..6c8b32d 100644
--- a/clang/unittests/Driver/ToolChainTest.cpp
+++ b/clang/unittests/Driver/ToolChainTest.cpp
@@ -662,7 +662,7 @@ struct FileSystemWithError : public llvm::vfs::FileSystem {
     return std::make_error_code(std::errc::no_such_file_or_directory);
   }
   llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-  openFileForRead(const Twine &Path) override {
+  openFileForRead(const Twine &Path, bool IsText = true) override {
     return std::make_error_code(std::errc::permission_denied);
   }
   llvm::vfs::directory_iterator dir_begin(const Twine &Dir,
diff --git a/clang/unittests/Frontend/PCHPreambleTest.cpp b/clang/unittests/Frontend/PCHPreambleTest.cpp
index 2ce24c9..137dcf2 100644
--- a/clang/unittests/Frontend/PCHPreambleTest.cpp
+++ b/clang/unittests/Frontend/PCHPreambleTest.cpp
@@ -36,10 +36,10 @@ class ReadCountingInMemoryFileSystem : public vfs::InMemoryFileSystem
   std::map<std::string, unsigned> ReadCounts;
 
 public:
-  ErrorOr<std::unique_ptr<vfs::File>> openFileForRead(const Twine &Path) override
-  {
+  ErrorOr<std::unique_ptr<vfs::File>>
+  openFileForRead(const Twine &Path, bool IsText = true) override {
     ++ReadCounts[Canonicalize(Path)];
-    return InMemoryFileSystem::openFileForRead(Path);
+    return InMemoryFileSystem::openFileForRead(Path, IsText);
   }
 
   unsigned GetReadCount(const Twine &Path) const
diff --git a/clang/unittests/Tooling/DependencyScanning/DependencyScannerTest.cpp b/clang/unittests/Tooling/DependencyScanning/DependencyScannerTest.cpp
index ec0e143..1012016e 100644
--- a/clang/unittests/Tooling/DependencyScanning/DependencyScannerTest.cpp
+++ b/clang/unittests/Tooling/DependencyScanning/DependencyScannerTest.cpp
@@ -277,9 +277,9 @@ TEST(DependencyScanner, ScanDepsWithModuleLookup) {
     }
 
     llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>
-    openFileForRead(const Twine &Path) override {
+    openFileForRead(const Twine &Path, bool IsText = true) override {
       ReadFiles.push_back(Path.str());
-      return ProxyFileSystem::openFileForRead(Path);
+      return ProxyFileSystem::openFileForRead(Path, IsText);
     }
   };