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, 36 insertions, 16 deletions

diff --git a/lldb/source/Core/StreamFile.cpp b/lldb/source/Core/StreamFile.cpp
index 17662a43604..fe5d7413114 100644
--- a/lldb/source/Core/StreamFile.cpp
+++ b/lldb/source/Core/StreamFile.cpp
@@ -8,6 +8,7 @@
 
 #include "lldb/Core/StreamFile.h"
 #include "lldb/Host/FileSystem.h"
+#include "lldb/Utility/Log.h"
 
 #include <stdio.h>
 
@@ -15,35 +16,54 @@ using namespace lldb;
 using namespace lldb_private;
 
 // StreamFile constructor
-StreamFile::StreamFile() : Stream(), m_file() {}
+StreamFile::StreamFile() : Stream() { m_file_sp = std::make_shared<File>(); }
 
 StreamFile::StreamFile(uint32_t flags, uint32_t addr_size, ByteOrder byte_order)
-    : Stream(flags, addr_size, byte_order), m_file() {}
+    : Stream(flags, addr_size, byte_order) {
+  m_file_sp = std::make_shared<File>();
+}
 
-StreamFile::StreamFile(int fd, bool transfer_ownership)
-    : Stream(), m_file(fd, File::eOpenOptionWrite, transfer_ownership) {}
+StreamFile::StreamFile(int fd, bool transfer_ownership) : Stream() {
+  m_file_sp =
+      std::make_shared<File>(fd, File::eOpenOptionWrite, transfer_ownership);
+}
 
-StreamFile::StreamFile(FILE *fh, bool transfer_ownership)
-    : Stream(), m_file(fh, transfer_ownership) {}
+StreamFile::StreamFile(FILE *fh, bool transfer_ownership) : Stream() {
+  m_file_sp = std::make_shared<File>(fh, transfer_ownership);
+}
 
-StreamFile::StreamFile(const char *path) : Stream(), m_file() {
-  FileSystem::Instance().Open(m_file, FileSpec(path),
-                              File::eOpenOptionWrite |
-                                  File::eOpenOptionCanCreate |
-                                  File::eOpenOptionCloseOnExec);
+StreamFile::StreamFile(const char *path) : Stream() {
+  auto file = FileSystem::Instance().Open(
+      FileSpec(path), File::eOpenOptionWrite | File::eOpenOptionCanCreate |
+                          File::eOpenOptionCloseOnExec);
+  if (file)
+    m_file_sp = std::move(file.get());
+  else {
+    // TODO refactor this so the error gets popagated up instead of logged here.
+    LLDB_LOG_ERROR(GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST), file.takeError(),
+                   "Cannot open {1}: {0}", path);
+    m_file_sp = std::make_shared<File>();
+  }
 }
 
 StreamFile::StreamFile(const char *path, uint32_t options, uint32_t permissions)
-    : Stream(), m_file() {
-
-  FileSystem::Instance().Open(m_file, FileSpec(path), options, permissions);
+    : Stream() {
+  auto file = FileSystem::Instance().Open(FileSpec(path), options, permissions);
+  if (file)
+    m_file_sp = std::move(file.get());
+  else {
+    // TODO refactor this so the error gets popagated up instead of logged here.
+    LLDB_LOG_ERROR(GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST), file.takeError(),
+                   "Cannot open {1}: {0}", path);
+    m_file_sp = std::make_shared<File>();
+  }
 }
 
 StreamFile::~StreamFile() {}
 
-void StreamFile::Flush() { m_file.Flush(); }
+void StreamFile::Flush() { m_file_sp->Flush(); }
 
 size_t StreamFile::WriteImpl(const void *s, size_t length) {
-  m_file.Write(s, length);
+  m_file_sp->Write(s, length);
   return length;
 }