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, 14 insertions, 10 deletions

diff --git a/lldb/source/Target/ModuleCache.cpp b/lldb/source/Target/ModuleCache.cpp
index cd3f211b81c..124cdacfb4d 100644
--- a/lldb/source/Target/ModuleCache.cpp
+++ b/lldb/source/Target/ModuleCache.cpp
@@ -48,7 +48,7 @@ std::string GetEscapedHostname(const char *hostname) {
 
 class ModuleLock {
 private:
-  File m_file;
+  FileUP m_file_up;
   std::unique_ptr<lldb_private::LockFile> m_lock;
   FileSpec m_file_spec;
 
@@ -157,16 +157,19 @@ ModuleLock::ModuleLock(const FileSpec &root_dir_spec, const UUID &uuid,
     return;
 
   m_file_spec = JoinPath(lock_dir_spec, uuid.GetAsString().c_str());
-  FileSystem::Instance().Open(m_file, m_file_spec,
-                              File::eOpenOptionWrite |
-                                  File::eOpenOptionCanCreate |
-                                  File::eOpenOptionCloseOnExec);
-  if (!m_file) {
-    error.SetErrorToErrno();
+
+  auto file = FileSystem::Instance().Open(
+      m_file_spec, File::eOpenOptionWrite | File::eOpenOptionCanCreate |
+                       File::eOpenOptionCloseOnExec);
+  if (file)
+    m_file_up = std::move(file.get());
+  else {
+    m_file_up.reset();
+    error = Status(file.takeError());
     return;
   }
 
-  m_lock.reset(new lldb_private::LockFile(m_file.GetDescriptor()));
+  m_lock.reset(new lldb_private::LockFile(m_file_up->GetDescriptor()));
   error = m_lock->WriteLock(0, 1);
   if (error.Fail())
     error.SetErrorStringWithFormat("Failed to lock file: %s",
@@ -174,10 +177,11 @@ ModuleLock::ModuleLock(const FileSpec &root_dir_spec, const UUID &uuid,
 }
 
 void ModuleLock::Delete() {
-  if (!m_file)
+  if (!m_file_up)
     return;
 
-  m_file.Close();
+  m_file_up->Close();
+  m_file_up.reset();
   llvm::sys::fs::remove(m_file_spec.GetPath());
 }