Convert FileSystem::Open() to return Expected<FileUP>

Summary:
This patch converts FileSystem::Open from this prototype:

Status
Open(File &File, const FileSpec &file_spec, ...);

to this one:

llvm::Expected<std::unique_ptr<File>>
Open(const FileSpec &file_spec, ...);

This is beneficial on its own, as llvm::Expected is a more modern
and recommended error type than Status.  It is also a necessary step
towards https://reviews.llvm.org/D67891, and further developments
for lldb_private::File.

Reviewers: JDevlieghere, jasonmolenda, labath

Reviewed By: labath

Subscribers: mgorny, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D67996

llvm-svn: 373003

1 files changed, 12 insertions, 7 deletions

diff --git a/lldb/source/Expression/REPL.cpp b/lldb/source/Expression/REPL.cpp
index f7bd86391f5..cfa520981be 100644
--- a/lldb/source/Expression/REPL.cpp
+++ b/lldb/source/Expression/REPL.cpp
@@ -398,17 +398,22 @@ void REPL::IOHandlerInputComplete(IOHandler &io_handler, std::string &code) {
 
           // Update our code on disk
           if (!m_repl_source_path.empty()) {
-            lldb_private::File file;
-            FileSystem::Instance().Open(file, FileSpec(m_repl_source_path),
+            auto file = FileSystem::Instance().Open(FileSpec(m_repl_source_path),
                                         File::eOpenOptionWrite |
                                             File::eOpenOptionTruncate |
                                             File::eOpenOptionCanCreate,
                                         lldb::eFilePermissionsFileDefault);
-            std::string code(m_code.CopyList());
-            code.append(1, '\n');
-            size_t bytes_written = code.size();
-            file.Write(code.c_str(), bytes_written);
-            file.Close();
+            if (file) {
+              std::string code(m_code.CopyList());
+              code.append(1, '\n');
+              size_t bytes_written = code.size();
+              file.get()->Write(code.c_str(), bytes_written);
+              file.get()->Close();
+            } else {
+              std::string message = llvm::toString(file.takeError());
+              error_sp->Printf("error: couldn't open %s: %s\n",
+                               m_repl_source_path.c_str(), message.c_str());
+            }
 
             // Now set the default file and line to the REPL source file
             m_target.GetSourceManager().SetDefaultFileAndLine(