Revert "Extract construction of DataBufferLLVM into FileSystem"

It broke the lldb sanitizer bots.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@346694 91177308-0d34-0410-b5e6-96231b3b80d8

18 files changed, 73 insertions, 94 deletions

diff --git a/include/lldb/Host/FileSystem.h b/include/lldb/Host/FileSystem.h
index 2122860a5..730cbd2a4 100644
--- a/include/lldb/Host/FileSystem.h
+++ b/include/lldb/Host/FileSystem.h
@@ -11,7 +11,6 @@
 #define liblldb_Host_FileSystem_h
 
 #include "lldb/Host/File.h"
-#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/FileSpec.h"
 #include "lldb/Utility/Status.h"
 
@@ -95,12 +94,6 @@ public:
   bool IsDirectory(const llvm::Twine &path) const;
   /// @}
 
-  /// Returns whether the given path is local to the file system.
-  /// @{
-  bool IsLocal(const FileSpec &file_spec) const;
-  bool IsLocal(const llvm::Twine &path) const;
-  /// @}
-
   /// Make the given file path absolute.
   /// @{
   std::error_code MakeAbsolute(llvm::SmallVectorImpl<char> &path) const;
@@ -113,16 +106,6 @@ public:
   void Resolve(FileSpec &file_spec);
   /// @}
 
-  //// Create memory buffer from path.
-  /// @{
-  std::shared_ptr<DataBufferLLVM> CreateDataBuffer(const llvm::Twine &path,
-                                                   uint64_t size = 0,
-                                                   uint64_t offset = 0);
-  std::shared_ptr<DataBufferLLVM> CreateDataBuffer(const FileSpec &file_spec,
-                                                   uint64_t size = 0,
-                                                   uint64_t offset = 0);
-  /// @}
-
   /// Call into the Host to see if it can help find the file.
   bool ResolveExecutableLocation(FileSpec &file_spec);
 
diff --git a/include/lldb/Utility/DataBufferLLVM.h b/include/lldb/Utility/DataBufferLLVM.h
index 947ddb54d..e90caf65b 100644
--- a/include/lldb/Utility/DataBufferLLVM.h
+++ b/include/lldb/Utility/DataBufferLLVM.h
@@ -23,11 +23,16 @@ class Twine;
 
 namespace lldb_private {
 
-class FileSystem;
 class DataBufferLLVM : public DataBuffer {
 public:
   ~DataBufferLLVM();
 
+  static std::shared_ptr<DataBufferLLVM>
+  CreateSliceFromPath(const llvm::Twine &Path, uint64_t Size, uint64_t Offset);
+
+  static std::shared_ptr<DataBufferLLVM>
+  CreateFromPath(const llvm::Twine &Path);
+
   uint8_t *GetBytes() override;
   const uint8_t *GetBytes() const override;
   lldb::offset_t GetByteSize() const override;
@@ -35,7 +40,6 @@ public:
   char *GetChars() { return reinterpret_cast<char *>(GetBytes()); }
 
 private:
-  friend FileSystem;
   /// Construct a DataBufferLLVM from \p Buffer.  \p Buffer must be a valid
   /// pointer.
   explicit DataBufferLLVM(std::unique_ptr<llvm::WritableMemoryBuffer> Buffer);
diff --git a/source/API/SBSection.cpp b/source/API/SBSection.cpp
index 7193857d1..9da5d170d 100644
--- a/source/API/SBSection.cpp
+++ b/source/API/SBSection.cpp
@@ -14,6 +14,7 @@
 #include "lldb/Core/Section.h"
 #include "lldb/Symbol/ObjectFile.h"
 #include "lldb/Utility/DataBuffer.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/DataExtractor.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/StreamString.h"
@@ -165,7 +166,7 @@ SBData SBSection::GetSectionData(uint64_t offset, uint64_t size) {
             else
               file_size = 0;
           }
-          auto data_buffer_sp = FileSystem::Instance().CreateDataBuffer(
+          auto data_buffer_sp = DataBufferLLVM::CreateSliceFromPath(
               objfile->GetFileSpec().GetPath(), file_size, file_offset);
           if (data_buffer_sp && data_buffer_sp->GetByteSize() > 0) {
             DataExtractorSP data_extractor_sp(
diff --git a/source/Commands/CommandObjectMemory.cpp b/source/Commands/CommandObjectMemory.cpp
index fcd9cd848..6a848d536 100644
--- a/source/Commands/CommandObjectMemory.cpp
+++ b/source/Commands/CommandObjectMemory.cpp
@@ -1357,7 +1357,7 @@ protected:
       size_t length = SIZE_MAX;
       if (item_byte_size > 1)
         length = item_byte_size;
-      auto data_sp = FileSystem::Instance().CreateDataBuffer(
+      auto data_sp = DataBufferLLVM::CreateSliceFromPath(
           m_memory_options.m_infile.GetPath(), length,
           m_memory_options.m_infile_offset);
       if (data_sp) {
diff --git a/source/Core/SourceManager.cpp b/source/Core/SourceManager.cpp
index 16cc1b805..cda23f564 100644
--- a/source/Core/SourceManager.cpp
+++ b/source/Core/SourceManager.cpp
@@ -442,7 +442,7 @@ void SourceManager::File::CommonInitializer(const FileSpec &file_spec,
   }
 
   if (m_mod_time != llvm::sys::TimePoint<>())
-    m_data_sp = FileSystem::Instance().CreateDataBuffer(m_file_spec);
+    m_data_sp = DataBufferLLVM::CreateFromPath(m_file_spec.GetPath());
 }
 
 uint32_t SourceManager::File::GetLineOffset(uint32_t line) {
@@ -520,7 +520,7 @@ void SourceManager::File::UpdateIfNeeded() {
   if (curr_mod_time != llvm::sys::TimePoint<>() &&
       m_mod_time != curr_mod_time) {
     m_mod_time = curr_mod_time;
-    m_data_sp = FileSystem::Instance().CreateDataBuffer(m_file_spec);
+    m_data_sp = DataBufferLLVM::CreateFromPath(m_file_spec.GetPath());
     m_offsets.clear();
   }
 }
diff --git a/source/Host/common/FileSystem.cpp b/source/Host/common/FileSystem.cpp
index 95b453073..a9ed5bd18 100644
--- a/source/Host/common/FileSystem.cpp
+++ b/source/Host/common/FileSystem.cpp
@@ -135,16 +135,6 @@ bool FileSystem::IsDirectory(const FileSpec &file_spec) const {
   return IsDirectory(file_spec.GetPath());
 }
 
-bool FileSystem::IsLocal(const Twine &path) const {
-  bool b;
-  m_fs->isLocal(path, b);
-  return b;
-}
-
-bool FileSystem::IsLocal(const FileSpec &file_spec) const {
-  return IsLocal(file_spec.GetPath());
-}
-
 void FileSystem::EnumerateDirectory(Twine path, bool find_directories,
                                     bool find_files, bool find_other,
                                     EnumerateDirectoryCallbackType callback,
@@ -228,34 +218,6 @@ void FileSystem::Resolve(FileSpec &file_spec) {
   file_spec.SetIsResolved(true);
 }
 
-std::shared_ptr<DataBufferLLVM>
-FileSystem::CreateDataBuffer(const llvm::Twine &path, uint64_t size,
-                             uint64_t offset) {
-  const bool is_volatile = !IsLocal(path);
-
-  std::unique_ptr<llvm::WritableMemoryBuffer> buffer;
-  if (size == 0) {
-    auto buffer_or_error =
-        llvm::WritableMemoryBuffer::getFile(path, -1, is_volatile);
-    if (!buffer_or_error)
-      return nullptr;
-    buffer = std::move(*buffer_or_error);
-  } else {
-    auto buffer_or_error = llvm::WritableMemoryBuffer::getFileSlice(
-        path, size, offset, is_volatile);
-    if (!buffer_or_error)
-      return nullptr;
-    buffer = std::move(*buffer_or_error);
-  }
-  return std::shared_ptr<DataBufferLLVM>(new DataBufferLLVM(std::move(buffer)));
-}
-
-std::shared_ptr<DataBufferLLVM>
-FileSystem::CreateDataBuffer(const FileSpec &file_spec, uint64_t size,
-                             uint64_t offset) {
-  return CreateDataBuffer(file_spec.GetPath(), size, offset);
-}
-
 bool FileSystem::ResolveExecutableLocation(FileSpec &file_spec) {
   // If the directory is set there's nothing to do.
   const ConstString &directory = file_spec.GetDirectory();
diff --git a/source/Host/common/Host.cpp b/source/Host/common/Host.cpp
index 55d174c90..11af400a4 100644
--- a/source/Host/common/Host.cpp
+++ b/source/Host/common/Host.cpp
@@ -564,7 +564,7 @@ Status Host::RunShellCommand(const Args &args, const FileSpec &working_dir,
                 "shell command output is too large to fit into a std::string");
           } else {
             auto Buffer =
-                FileSystem::Instance().CreateDataBuffer(output_file_spec);
+                DataBufferLLVM::CreateFromPath(output_file_spec.GetPath());
             if (error.Success())
               command_output_ptr->assign(Buffer->GetChars(),
                                          Buffer->GetByteSize());
diff --git a/source/Host/linux/Host.cpp b/source/Host/linux/Host.cpp
index bd596f8cb..1008706bd 100644
--- a/source/Host/linux/Host.cpp
+++ b/source/Host/linux/Host.cpp
@@ -28,6 +28,7 @@
 #include "lldb/Host/Host.h"
 #include "lldb/Host/HostInfo.h"
 #include "lldb/Host/linux/Support.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/DataExtractor.h"
 
 using namespace lldb;
@@ -121,7 +122,7 @@ static bool IsDirNumeric(const char *dname) {
 static ArchSpec GetELFProcessCPUType(llvm::StringRef exe_path) {
   Log *log = GetLogIfAllCategoriesSet(LIBLLDB_LOG_HOST);
 
-  auto buffer_sp = FileSystem::Instance().CreateDataBuffer(exe_path, 0x20, 0);
+  auto buffer_sp = DataBufferLLVM::CreateSliceFromPath(exe_path, 0x20, 0);
   if (!buffer_sp)
     return ArchSpec();
 
diff --git a/source/Interpreter/OptionValueFileSpec.cpp b/source/Interpreter/OptionValueFileSpec.cpp
index 735a7d863..92b490023 100644
--- a/source/Interpreter/OptionValueFileSpec.cpp
+++ b/source/Interpreter/OptionValueFileSpec.cpp
@@ -14,6 +14,7 @@
 #include "lldb/Interpreter/CommandCompletions.h"
 #include "lldb/Interpreter/CommandInterpreter.h"
 #include "lldb/Utility/Args.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/State.h"
 
 using namespace lldb;
@@ -113,8 +114,7 @@ const lldb::DataBufferSP &OptionValueFileSpec::GetFileContents() {
     const auto file_mod_time = FileSystem::Instance().GetModificationTime(m_current_value);
     if (m_data_sp && m_data_mod_time == file_mod_time)
       return m_data_sp;
-    m_data_sp =
-        FileSystem::Instance().CreateDataBuffer(m_current_value.GetPath());
+    m_data_sp = DataBufferLLVM::CreateFromPath(m_current_value.GetPath());
     m_data_mod_time = file_mod_time;
   }
   return m_data_sp;
diff --git a/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp b/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp
index 95daadfac..76eedb8f1 100644
--- a/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp
+++ b/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp
@@ -36,6 +36,7 @@
 #include "lldb/Target/Thread.h"
 #include "lldb/Utility/Args.h"
 #include "lldb/Utility/ConstString.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/RegisterValue.h"
 #include "lldb/Utility/RegularExpression.h"
@@ -2539,7 +2540,7 @@ bool RenderScriptRuntime::LoadAllocation(Stream &strm, const uint32_t alloc_id,
   }
 
   // Read file into data buffer
-  auto data_sp = FileSystem::Instance().CreateDataBuffer(file.GetPath());
+  auto data_sp = DataBufferLLVM::CreateFromPath(file.GetPath());
 
   // Cast start of buffer to FileHeader and use pointer to read metadata
   void *file_buf = data_sp->GetBytes();
@@ -3080,8 +3081,7 @@ bool RSModuleDescriptor::ParseRSInfo() {
   const addr_t size = info_sym->GetByteSize();
   const FileSpec fs = m_module->GetFileSpec();
 
-  auto buffer =
-      FileSystem::Instance().CreateDataBuffer(fs.GetPath(), size, addr);
+  auto buffer = DataBufferLLVM::CreateSliceFromPath(fs.GetPath(), size, addr);
   if (!buffer)
     return false;
 
diff --git a/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp b/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp
index ae7409352..347870ec2 100644
--- a/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp
+++ b/source/Plugins/ObjectContainer/BSD-Archive/ObjectContainerBSDArchive.cpp
@@ -33,6 +33,7 @@ typedef struct ar_hdr {
 #include "lldb/Host/FileSystem.h"
 #include "lldb/Symbol/ObjectFile.h"
 #include "lldb/Utility/ArchSpec.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Stream.h"
 #include "lldb/Utility/Timer.h"
 
@@ -312,7 +313,7 @@ ObjectContainer *ObjectContainerBSDArchive::CreateInstance(
       // file gets updated by a new build while this .a file is being used for
       // debugging
       DataBufferSP archive_data_sp =
-          FileSystem::Instance().CreateDataBuffer(*file, length, file_offset);
+          DataBufferLLVM::CreateSliceFromPath(file->GetPath(), length, file_offset);
       if (!archive_data_sp)
         return nullptr;
 
@@ -467,7 +468,7 @@ size_t ObjectContainerBSDArchive::GetModuleSpecifications(
   if (!archive_sp) {
     set_archive_arch = true;
     data_sp =
-        FileSystem::Instance().CreateDataBuffer(file, file_size, file_offset);
+        DataBufferLLVM::CreateSliceFromPath(file.GetPath(), file_size, file_offset);
     if (data_sp) {
       data.SetData(data_sp, 0, data_sp->GetByteSize());
       archive_sp = Archive::ParseAndCacheArchiveForFile(
diff --git a/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp b/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
index c9359df7f..c287d14b6 100644
--- a/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
+++ b/source/Plugins/Platform/MacOSX/PlatformDarwin.cpp
@@ -30,6 +30,7 @@
 #include "lldb/Target/Platform.h"
 #include "lldb/Target/Process.h"
 #include "lldb/Target/Target.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/Status.h"
 #include "lldb/Utility/Timer.h"
@@ -1166,7 +1167,7 @@ const char *PlatformDarwin::GetDeveloperDirectory() {
       xcode_dir_path.append("/usr/share/xcode-select/xcode_dir_path");
       temp_file_spec.SetFile(xcode_dir_path, FileSpec::Style::native);
       auto dir_buffer =
-          FileSystem::Instance().CreateDataBuffer(temp_file_spec.GetPath());
+          DataBufferLLVM::CreateFromPath(temp_file_spec.GetPath());
       if (dir_buffer && dir_buffer->GetByteSize() > 0) {
         llvm::StringRef path_ref(dir_buffer->GetChars());
         // Trim tailing newlines and make sure there is enough room for a null
diff --git a/source/Plugins/Process/elf-core/ProcessElfCore.cpp b/source/Plugins/Process/elf-core/ProcessElfCore.cpp
index 56e03ce1b..f1e0f46a8 100644
--- a/source/Plugins/Process/elf-core/ProcessElfCore.cpp
+++ b/source/Plugins/Process/elf-core/ProcessElfCore.cpp
@@ -20,6 +20,7 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Target/UnixSignals.h"
 #include "lldb/Utility/DataBufferHeap.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/State.h"
 
@@ -57,8 +58,8 @@ lldb::ProcessSP ProcessElfCore::CreateInstance(lldb::TargetSP target_sp,
     // the header extension.
     const size_t header_size = sizeof(llvm::ELF::Elf64_Ehdr);
 
-    auto data_sp = FileSystem::Instance().CreateDataBuffer(
-        crash_file->GetPath(), header_size, 0);
+    auto data_sp = DataBufferLLVM::CreateSliceFromPath(crash_file->GetPath(),
+                                                       header_size, 0);
     if (data_sp && data_sp->GetByteSize() == header_size &&
         elf::ELFHeader::MagicBytesMatch(data_sp->GetBytes())) {
       elf::ELFHeader elf_header;
diff --git a/source/Plugins/Process/mach-core/ProcessMachCore.cpp b/source/Plugins/Process/mach-core/ProcessMachCore.cpp
index bdb6a6041..c2098c1be 100644
--- a/source/Plugins/Process/mach-core/ProcessMachCore.cpp
+++ b/source/Plugins/Process/mach-core/ProcessMachCore.cpp
@@ -26,6 +26,7 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Target/Thread.h"
 #include "lldb/Utility/DataBuffer.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/State.h"
 
@@ -62,8 +63,8 @@ lldb::ProcessSP ProcessMachCore::CreateInstance(lldb::TargetSP target_sp,
   lldb::ProcessSP process_sp;
   if (crash_file) {
     const size_t header_size = sizeof(llvm::MachO::mach_header);
-    auto data_sp = FileSystem::Instance().CreateDataBuffer(
-        crash_file->GetPath(), header_size, 0);
+    auto data_sp =
+        DataBufferLLVM::CreateSliceFromPath(crash_file->GetPath(), header_size, 0);
     if (data_sp && data_sp->GetByteSize() == header_size) {
       DataExtractor data(data_sp, lldb::eByteOrderLittle, 4);
 
diff --git a/source/Plugins/Process/minidump/ProcessMinidump.cpp b/source/Plugins/Process/minidump/ProcessMinidump.cpp
index 97e137622..b679199cb 100644
--- a/source/Plugins/Process/minidump/ProcessMinidump.cpp
+++ b/source/Plugins/Process/minidump/ProcessMinidump.cpp
@@ -19,6 +19,7 @@
 #include "lldb/Target/SectionLoadList.h"
 #include "lldb/Target/Target.h"
 #include "lldb/Target/UnixSignals.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/LLDBAssert.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/State.h"
@@ -98,8 +99,8 @@ lldb::ProcessSP ProcessMinidump::CreateInstance(lldb::TargetSP target_sp,
   lldb::ProcessSP process_sp;
   // Read enough data for the Minidump header
   constexpr size_t header_size = sizeof(MinidumpHeader);
-  auto DataPtr = FileSystem::Instance().CreateDataBuffer(crash_file->GetPath(),
-                                                         header_size, 0);
+  auto DataPtr =
+      DataBufferLLVM::CreateSliceFromPath(crash_file->GetPath(), header_size, 0);
   if (!DataPtr)
     return nullptr;
 
@@ -111,8 +112,7 @@ lldb::ProcessSP ProcessMinidump::CreateInstance(lldb::TargetSP target_sp,
   if (header == nullptr)
     return nullptr;
 
-  auto AllData =
-      FileSystem::Instance().CreateDataBuffer(crash_file->GetPath(), -1, 0);
+  auto AllData = DataBufferLLVM::CreateSliceFromPath(crash_file->GetPath(), -1, 0);
   if (!AllData)
     return nullptr;
 
diff --git a/source/Symbol/ObjectFile.cpp b/source/Symbol/ObjectFile.cpp
index d56acd230..bd94ec0ad 100644
--- a/source/Symbol/ObjectFile.cpp
+++ b/source/Symbol/ObjectFile.cpp
@@ -19,6 +19,7 @@
 #include "lldb/Target/Target.h"
 #include "lldb/Utility/DataBuffer.h"
 #include "lldb/Utility/DataBufferHeap.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/RegularExpression.h"
 #include "lldb/Utility/Timer.h"
@@ -74,8 +75,8 @@ ObjectFile::FindPlugin(const lldb::ModuleSP &module_sp, const FileSpec *file,
         // container plug-ins can use these bytes to see if they can parse this
         // file.
         if (file_size > 0) {
-          data_sp = FileSystem::Instance().CreateDataBuffer(file->GetPath(),
-                                                            512, file_offset);
+          data_sp =
+              DataBufferLLVM::CreateSliceFromPath(file->GetPath(), 512, file_offset);
           data_offset = 0;
         }
       }
@@ -119,8 +120,8 @@ ObjectFile::FindPlugin(const lldb::ModuleSP &module_sp, const FileSpec *file,
             }
             // We failed to find any cached object files in the container plug-
             // ins, so lets read the first 512 bytes and try again below...
-            data_sp = FileSystem::Instance().CreateDataBuffer(
-                archive_file.GetPath(), 512, file_offset);
+            data_sp = DataBufferLLVM::CreateSliceFromPath(archive_file.GetPath(),
+                                                     512, file_offset);
           }
         }
       }
@@ -208,8 +209,7 @@ size_t ObjectFile::GetModuleSpecifications(const FileSpec &file,
                                            lldb::offset_t file_offset,
                                            lldb::offset_t file_size,
                                            ModuleSpecList &specs) {
-  DataBufferSP data_sp =
-      FileSystem::Instance().CreateDataBuffer(file.GetPath(), 512, file_offset);
+  DataBufferSP data_sp = DataBufferLLVM::CreateSliceFromPath(file.GetPath(), 512, file_offset);
   if (data_sp) {
     if (file_size == 0) {
       const lldb::offset_t actual_file_size =
@@ -682,5 +682,5 @@ void ObjectFile::RelocateSection(lldb_private::Section *section)
 
 DataBufferSP ObjectFile::MapFileData(const FileSpec &file, uint64_t Size,
                                      uint64_t Offset) {
-  return FileSystem::Instance().CreateDataBuffer(file.GetPath(), Size, Offset);
+  return DataBufferLLVM::CreateSliceFromPath(file.GetPath(), Size, Offset);
 }
diff --git a/source/Utility/DataBufferLLVM.cpp b/source/Utility/DataBufferLLVM.cpp
index 0ab3fe5af..848701290 100644
--- a/source/Utility/DataBufferLLVM.cpp
+++ b/source/Utility/DataBufferLLVM.cpp
@@ -27,6 +27,34 @@ DataBufferLLVM::DataBufferLLVM(
 
 DataBufferLLVM::~DataBufferLLVM() {}
 
+std::shared_ptr<DataBufferLLVM>
+DataBufferLLVM::CreateSliceFromPath(const llvm::Twine &Path, uint64_t Size,
+                                    uint64_t Offset) {
+  // If the file resides non-locally, pass the volatile flag so that we don't
+  // mmap it.
+  bool IsVolatile = !llvm::sys::fs::is_local(Path);
+
+  auto Buffer =
+      llvm::WritableMemoryBuffer::getFileSlice(Path, Size, Offset, IsVolatile);
+  if (!Buffer)
+    return nullptr;
+  return std::shared_ptr<DataBufferLLVM>(
+      new DataBufferLLVM(std::move(*Buffer)));
+}
+
+std::shared_ptr<DataBufferLLVM>
+DataBufferLLVM::CreateFromPath(const llvm::Twine &Path) {
+  // If the file resides non-locally, pass the volatile flag so that we don't
+  // mmap it.
+  bool IsVolatile = !llvm::sys::fs::is_local(Path);
+
+  auto Buffer = llvm::WritableMemoryBuffer::getFile(Path, -1, IsVolatile);
+  if (!Buffer)
+    return nullptr;
+  return std::shared_ptr<DataBufferLLVM>(
+      new DataBufferLLVM(std::move(*Buffer)));
+}
+
 uint8_t *DataBufferLLVM::GetBytes() {
   return reinterpret_cast<uint8_t *>(Buffer->getBufferStart());
 }
diff --git a/unittests/Process/minidump/MinidumpParserTest.cpp b/unittests/Process/minidump/MinidumpParserTest.cpp
index 57f27d4f6..f3f9d5727 100644
--- a/unittests/Process/minidump/MinidumpParserTest.cpp
+++ b/unittests/Process/minidump/MinidumpParserTest.cpp
@@ -15,9 +15,9 @@
 #include "Plugins/Process/minidump/RegisterContextMinidump_x86_64.h"
 
 #include "TestingSupport/TestUtilities.h"
-#include "lldb/Host/FileSystem.h"
 #include "lldb/Target/MemoryRegionInfo.h"
 #include "lldb/Utility/ArchSpec.h"
+#include "lldb/Utility/DataBufferLLVM.h"
 #include "lldb/Utility/DataExtractor.h"
 #include "lldb/Utility/FileSpec.h"
 #include "llvm/ADT/ArrayRef.h"
@@ -37,13 +37,9 @@ using namespace minidump;
 
 class MinidumpParserTest : public testing::Test {
 public:
-  void SetUp() override { FileSystem::Initialize(); }
-
-  void TearDown() override { FileSystem::Terminate(); }
-
   void SetUpData(const char *minidump_filename) {
     std::string filename = GetInputFilePath(minidump_filename);
-    auto BufferPtr = FileSystem::Instance().CreateDataBuffer(filename, -1, 0);
+    auto BufferPtr = DataBufferLLVM::CreateSliceFromPath(filename, -1, 0);
     ASSERT_NE(BufferPtr, nullptr);
     llvm::Optional<MinidumpParser> optional_parser =
         MinidumpParser::Create(BufferPtr);
@@ -57,7 +53,7 @@ public:
   void InvalidMinidump(const char *minidump_filename, uint64_t load_size) {
     std::string filename = GetInputFilePath(minidump_filename);
     auto BufferPtr =
-        FileSystem::Instance().CreateDataBuffer(filename, load_size, 0);
+        DataBufferLLVM::CreateSliceFromPath(filename, load_size, 0);
     ASSERT_NE(BufferPtr, nullptr);
 
     llvm::Optional<MinidumpParser> optional_parser =
@@ -92,7 +88,7 @@ TEST_F(MinidumpParserTest, GetThreadListNotPadded) {
   // after the thread count.
   SetUpData("thread-list-not-padded.dmp");
   llvm::ArrayRef<MinidumpThread> thread_list;
-
+  
   thread_list = parser->GetThreads();
   ASSERT_EQ(2UL, thread_list.size());
   EXPECT_EQ(0x11223344UL, thread_list[0].thread_id);