Allow debugserver to detach from the target if the connection is

unexpectedly closed.

llvm-svn: 202110

lldb/tools/debugserver/source/DNB.cpp

@@ -650,6 +650,10 @@ DNBProcessDetach (nub_process_t pid)
     MachProcessSP procSP;
     if (GetProcessSP (pid, procSP))
     {
+        const bool remove = true;
+        DNBLogThreaded("Disabling breakpoints and watchpoints, and detaching from %d.", pid);
+        procSP->DisableAllBreakpoints(remove);
+        procSP->DisableAllWatchpoints (remove);
         return procSP->Detach();
     }
     return false;

lldb/tools/debugserver/source/MacOSX/MachProcess.cpp

@@ -307,14 +307,16 @@ MachProcess::SetState(nub_state_t new_state)
 }
 
 void
-MachProcess::Clear()
+MachProcess::Clear(bool detaching)
 {
     // Clear any cached thread list while the pid and task are still valid
 
     m_task.Clear();
     // Now clear out all member variables
     m_pid = INVALID_NUB_PROCESS;
-    CloseChildFileDescriptors();
+    if (!detaching)
+        CloseChildFileDescriptors();
+        
     m_path.clear();
     m_args.clear();
     SetState(eStateUnloaded);
@@ -554,7 +556,8 @@ MachProcess::Detach()
     m_task.Clear();
 
     // Clear out any notion of the process we once were
-    Clear();
+    const bool detaching = true;
+    Clear(detaching);
 
     SetState(eStateDetached);
 

lldb/tools/debugserver/source/MacOSX/MachProcess.h

@@ -258,7 +258,7 @@ private:
         eMachProcessFlagsAttached = (1 << 0),
         eMachProcessFlagsUsingSBS = (1 << 1)
     };
-    void                    Clear ();
+    void                    Clear (bool detaching = false);
     void                    ReplyToAllExceptions ();
     void                    PrivateResume ();
 

lldb/tools/debugserver/source/RNBContext.h

@@ -57,7 +57,8 @@ public:
         m_pid_pthread(),
         m_launch_status(),
         m_arg_vec (),
-        m_env_vec ()
+        m_env_vec (),
+        m_detach_on_error(false)
     {
     }
 
@@ -116,6 +117,10 @@ public:
     const char *    GetSTDOUTPath() { return m_stdout.empty() ? NULL : m_stdout.c_str(); }
     const char *    GetSTDERRPath() { return m_stderr.empty() ? NULL : m_stderr.c_str(); }
     const char *    GetWorkingDirPath() { return m_working_dir.empty() ? NULL : m_working_dir.c_str(); }
+    
+    void            SetDetachOnError(bool detach) { m_detach_on_error = detach; }
+    bool            GetDetachOnError () { return m_detach_on_error; }
+    
 protected:
     //------------------------------------------------------------------
     // Classes that inherit from RNBContext can see and modify these
@@ -133,6 +138,7 @@ protected:
     std::vector<std::string> m_arg_vec;
     std::vector<std::string> m_env_vec; // This will be unparsed - entries FOO=value
     std::string     m_working_directory;
+    bool            m_detach_on_error;
 
     void    StartProcessStatusThread();
     void    StopProcessStatusThread();

lldb/tools/debugserver/source/debugserver.cpp

@@ -63,6 +63,7 @@ static nub_launch_flavor_t g_launch_flavor = eLaunchFlavorDefault;
 int g_disable_aslr = 0;
 
 int g_isatty = 0;
+bool g_detach_on_error = false;
 
 #define RNBLogSTDOUT(fmt, ...) do { if (g_isatty) { fprintf(stdout, fmt, ## __VA_ARGS__); } else { _DNBLog(0, fmt, ## __VA_ARGS__); } } while (0)
 #define RNBLogSTDERR(fmt, ...) do { if (g_isatty) { fprintf(stderr, fmt, ## __VA_ARGS__); } else { _DNBLog(0, fmt, ## __VA_ARGS__); } } while (0)
@@ -571,8 +572,24 @@ RNBRunLoopInferiorExecuting (RNBRemote *remote)
                     // in its current state and listen for another connection...
                     if (ctx.ProcessStateRunning())
                     {
-                        DNBLog ("debugserver's event read thread is exiting, killing the inferior process.");
-                        DNBProcessKill (ctx.ProcessID());
+                        if (ctx.GetDetachOnError())
+                        {
+                            DNBLog ("debugserver's event read thread is exiting, detaching from the inferior process.");
+                            DNBProcessDetach (ctx.ProcessID());
+                        }
+                        else
+                        {
+                            DNBLog ("debugserver's event read thread is exiting, killing the inferior process.");
+                            DNBProcessKill (ctx.ProcessID());
+                        }
+                    }
+                    else
+                    {
+                        if (ctx.GetDetachOnError())
+                        {
+                            DNBLog ("debugserver's event read thread is exiting, detaching from the inferior process.");
+                            DNBProcessDetach (ctx.ProcessID());
+                        }
                     }
                 }
                 mode = eRNBRunLoopModeExit;
@@ -814,6 +831,7 @@ static struct option g_long_options[] =
     { "attach",             required_argument,  NULL,               'a' },
     { "arch",               required_argument,  NULL,               'A' },
     { "debug",              no_argument,        NULL,               'g' },
+    { "detach-on-error",    no_argument,        NULL,               'e' },
     { "verbose",            no_argument,        NULL,               'v' },
     { "lockdown",           no_argument,        &g_lockdown_opt,    1   },  // short option "-k"
     { "applist",            no_argument,        &g_applist_opt,     1   },  // short option "-t"
@@ -1011,6 +1029,9 @@ main (int argc, char *argv[])
                     }
                 }
                 break;
+                
+            case 'e':
+                g_detach_on_error = true;
 
             case 'W':
                 if (optarg && optarg[0])
@@ -1181,6 +1202,8 @@ main (int argc, char *argv[])
         }
     }
 
+    remote->Context().SetDetachOnError(g_detach_on_error);
+    
     remote->Initialize();
 
     // It is ok for us to set NULL as the logfile (this will disable any logging)