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, 15 insertions, 7 deletions

diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
index e8af9db2ce4..1d130672825 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
@@ -45,6 +45,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FormatAdapters.h"
 
 #include <memory>
 #include <mutex>
@@ -901,17 +902,24 @@ bool ScriptInterpreterPythonImpl::ExecuteOneLine(
         debugger.AdoptTopIOHandlerFilesIfInvalid(input_file_sp, output_file_sp,
                                                  error_file_sp);
     } else {
-      input_file_sp = std::make_shared<StreamFile>();
-      FileSystem::Instance().Open(input_file_sp->GetFile(),
+      auto nullin = FileSystem::Instance().Open(
                                   FileSpec(FileSystem::DEV_NULL),
                                   File::eOpenOptionRead);
-
-      output_file_sp = std::make_shared<StreamFile>();
-      FileSystem::Instance().Open(output_file_sp->GetFile(),
+      auto nullout = FileSystem::Instance().Open(
                                   FileSpec(FileSystem::DEV_NULL),
                                   File::eOpenOptionWrite);
-
-      error_file_sp = output_file_sp;
+      if (!nullin) {
+        result->AppendErrorWithFormatv("failed to open /dev/null: {0}\n",
+                                       llvm::fmt_consume(nullin.takeError()));
+        return false;
+      }
+      if (!nullout) {
+        result->AppendErrorWithFormatv("failed to open /dev/null: {0}\n",
+                                       llvm::fmt_consume(nullout.takeError()));
+        return false;
+      }
+      input_file_sp = std::make_shared<StreamFile>(std::move(nullin.get()));
+      error_file_sp = output_file_sp = std::make_shared<StreamFile>(std::move(nullout.get()));
     }
 
     FILE *in_file = input_file_sp->GetFile().GetStream();