Change LaunchThread interface to return an Expected for non-Apple-non-Windows

Fixes Linux build errors after D64163/r365226

llvm-svn: 365295

1 files changed, 6 insertions, 2 deletions

diff --git a/lldb/source/Host/common/MonitoringProcessLauncher.cpp b/lldb/source/Host/common/MonitoringProcessLauncher.cpp
index 2ee69353e19..55e9f69a089 100644
--- a/lldb/source/Host/common/MonitoringProcessLauncher.cpp
+++ b/lldb/source/Host/common/MonitoringProcessLauncher.cpp
@@ -53,8 +53,12 @@ MonitoringProcessLauncher::LaunchProcess(const ProcessLaunchInfo &launch_info,
     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
 
     assert(launch_info.GetMonitorProcessCallback());
-    process.StartMonitoring(launch_info.GetMonitorProcessCallback(),
-                            launch_info.GetMonitorSignals());
+    llvm::Expected<HostThread> maybe_thread =
+        process.StartMonitoring(launch_info.GetMonitorProcessCallback(),
+                                launch_info.GetMonitorSignals());
+    if (!maybe_thread)
+      error.SetErrorStringWithFormatv("failed to launch host thread: {}",
+                                      llvm::toString(maybe_thread.takeError()));
     if (log)
       log->PutCString("started monitoring child process.");
   } else {