5 files changed, 29 insertions, 21 deletions
diff --git a/lldb/source/Host/common/MonitoringProcessLauncher.cpp b/lldb/source/Host/common/MonitoringProcessLauncher.cpp
index 76c11454f57..efc10004b5f 100644
--- a/lldb/source/Host/common/MonitoringProcessLauncher.cpp
+++ b/lldb/source/Host/common/MonitoringProcessLauncher.cpp
@@ -9,6 +9,7 @@
 
 #include "lldb/Host/MonitoringProcessLauncher.h"
 #include "lldb/Host/HostProcess.h"
+#include "lldb/Target/Process.h"
 #include "lldb/Target/ProcessLaunchInfo.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/Status.h"
@@ -57,9 +58,18 @@ MonitoringProcessLauncher::LaunchProcess(const ProcessLaunchInfo &launch_info,
   if (process.GetProcessId() != LLDB_INVALID_PROCESS_ID) {
     Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
 
-    assert(launch_info.GetMonitorProcessCallback());
-    process.StartMonitoring(launch_info.GetMonitorProcessCallback(),
-                            launch_info.GetMonitorSignals());
+    Host::MonitorChildProcessCallback callback =
+        launch_info.GetMonitorProcessCallback();
+
+    bool monitor_signals = false;
+    if (callback) {
+      // If the ProcessLaunchInfo specified a callback, use that.
+      monitor_signals = launch_info.GetMonitorSignals();
+    } else {
+      callback = Process::SetProcessExitStatus;
+    }
+
+    process.StartMonitoring(callback, monitor_signals);
     if (log)
       log->PutCString("started monitoring child process.");
   } else {
diff --git a/lldb/source/Host/common/NativeProcessProtocol.cpp b/lldb/source/Host/common/NativeProcessProtocol.cpp
index 3e8648f8147..cc998e6da9f 100644
--- a/lldb/source/Host/common/NativeProcessProtocol.cpp
+++ b/lldb/source/Host/common/NativeProcessProtocol.cpp
@@ -13,6 +13,7 @@
 #include "lldb/Host/common/NativeRegisterContext.h"
 #include "lldb/Host/common/NativeThreadProtocol.h"
 #include "lldb/Host/common/SoftwareBreakpoint.h"
+#include "lldb/Target/Process.h"
 #include "lldb/Utility/LLDBAssert.h"
 #include "lldb/Utility/Log.h"
 #include "lldb/lldb-enumerations.h"
diff --git a/lldb/source/Host/macosx/Host.mm b/lldb/source/Host/macosx/Host.mm
index a1b6987070f..d87c6be915c 100644
--- a/lldb/source/Host/macosx/Host.mm
+++ b/lldb/source/Host/macosx/Host.mm
@@ -57,7 +57,7 @@
 #include "lldb/Host/ConnectionFileDescriptor.h"
 #include "lldb/Host/HostInfo.h"
 #include "lldb/Host/ThreadLauncher.h"
-#include "lldb/Target/ProcessLaunchInfo.h"
+#include "lldb/Target/Process.h"
 #include "lldb/Utility/ArchSpec.h"
 #include "lldb/Utility/CleanUp.h"
 #include "lldb/Utility/DataBufferHeap.h"
@@ -68,7 +68,6 @@
 #include "lldb/Utility/NameMatches.h"
 #include "lldb/Utility/StreamString.h"
 #include "lldb/Utility/StructuredData.h"
-#include "lldb/lldb-defines.h"
 
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Errno.h"
@@ -1498,9 +1497,15 @@ Status Host::LaunchProcess(ProcessLaunchInfo &launch_info) {
     launch_info.SetProcessID(pid);
 
     // Make sure we reap any processes we spawn or we will have zombies.
-    bool monitoring = launch_info.MonitorProcess());
-    UNUSED_IF_ASSERT_DISABLED(monitoring);
-    assert(monitoring);
+    if (!launch_info.MonitorProcess()) {
+      const bool monitor_signals = false;
+      Host::MonitorChildProcessCallback callback = nullptr;
+
+      if (!launch_info.GetFlags().Test(lldb::eLaunchFlagDontSetExitStatus))
+        callback = Process::SetProcessExitStatus;
+
+      StartMonitoringChildProcess(callback, pid, monitor_signals);
+    }
   } else {
     // Invalid process ID, something didn't go well
     if (error.Success())
diff --git a/lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp b/lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp
index eeff8f3518a..9b2c86a5f68 100644
--- a/lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp
+++ b/lldb/source/Plugins/Platform/POSIX/PlatformPOSIX.cpp
@@ -868,12 +868,11 @@ PlatformPOSIX::DebugProcess(ProcessLaunchInfo &launch_info, Debugger &debugger,
 
   if (IsHost()) {
     // We are going to hand this process off to debugserver which will be in
-    // charge of setting the exit status.  However, we still need to reap it
-    // from lldb. So, make sure we use a exit callback which does not set exit
-    // status.
-    const bool monitor_signals = false;
-    launch_info.SetMonitorProcessCallback(
-        &ProcessLaunchInfo::NoOpMonitorCallback, monitor_signals);
+    // charge of setting the exit status. We still need to reap it from lldb
+    // but if we let the monitor thread also set the exit status, we set up a
+    // race between debugserver & us for who will find out about the debugged
+    // process's death.
+    launch_info.GetFlags().Set(eLaunchFlagDontSetExitStatus);
     process_sp = Platform::DebugProcess(launch_info, debugger, target, error);
   } else {
     if (m_remote_platform_sp)
diff --git a/lldb/source/Target/ProcessLaunchInfo.cpp b/lldb/source/Target/ProcessLaunchInfo.cpp
index 9569750bc5f..60fe26bb60d 100644
--- a/lldb/source/Target/ProcessLaunchInfo.cpp
+++ b/lldb/source/Target/ProcessLaunchInfo.cpp
@@ -189,13 +189,6 @@ void ProcessLaunchInfo::SetMonitorProcessCallback(
   m_monitor_signals = monitor_signals;
 }
 
-bool ProcessLaunchInfo::NoOpMonitorCallback(lldb::pid_t pid, bool exited, int signal, int status) {
-  Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS);
-  LLDB_LOG(log, "pid = {0}, exited = {1}, signal = {2}, status = {3}", pid,
-           exited, signal, status);
-  return true;
-}
-
 bool ProcessLaunchInfo::MonitorProcess() const {
   if (m_monitor_callback && ProcessIDIsValid()) {
     Host::StartMonitoringChildProcess(m_monitor_callback, GetProcessID(),