[LLDB] [Windows] Fix Windows-specific race condition in LLDB for session lifetime

This can e.g. happen if the debugged executable exits before the initial
stop, e.g. if it fails to load dependent DLLs.

Add a virtual destructor to ProcessDebugger and let it clean up the
session, and make ProcessWindows::OnExitProcess call
ProcessDebugger::OnExitProcess for shared parts.

Fix suggestion by Adrian McCarthy.

Differential Revision: https://reviews.llvm.org/D69503

3 files changed, 5 insertions, 10 deletions

diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp b/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp
index 6ee882f7f88..cd780518fe2 100644
--- a/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp
+++ b/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.cpp
@@ -63,6 +63,8 @@ static bool IsPageExecutable(uint32_t protect) {
 
 namespace lldb_private {
 
+ProcessDebugger::~ProcessDebugger() {}
+
 lldb::pid_t ProcessDebugger::GetDebuggedProcessId() const {
   if (m_session_data)
     return m_session_data->m_debugger->GetProcess().GetProcessId();
diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.h b/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.h
index b4d053f8834..a4db76455ef 100644
--- a/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.h
+++ b/lldb/source/Plugins/Process/Windows/Common/ProcessDebugger.h
@@ -48,6 +48,8 @@ public:
 class ProcessDebugger {
 
 public:
+  virtual ~ProcessDebugger();
+
   virtual void OnExitProcess(uint32_t exit_code);
   virtual void OnDebuggerConnected(lldb::addr_t image_base);
   virtual ExceptionResult OnDebugException(bool first_chance,
diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp
index c4b7a6d1a90..d4e60ec2b43 100644
--- a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp
+++ b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp
@@ -625,16 +625,7 @@ void ProcessWindows::OnExitProcess(uint32_t exit_code) {
   SetProcessExitStatus(GetID(), true, 0, exit_code);
   SetPrivateState(eStateExited);
 
-  // If the process exits before any initial stop then notify the debugger
-  // of the error otherwise WaitForDebuggerConnection() will be blocked.
-  // An example of this issue is when a process fails to load a dependent DLL.
-  if (m_session_data && !m_session_data->m_initial_stop_received) {
-    Status error(exit_code, eErrorTypeWin32);
-    OnDebuggerError(error, 0);
-  }
-
-  // Reset the session.
-  m_session_data.reset();
+  ProcessDebugger::OnExitProcess(exit_code);
 }
 
 void ProcessWindows::OnDebuggerConnected(lldb::addr_t image_base) {