lldb::ProcessSP
Platform::DebugProcess (ProcessLaunchInfo &launch_info,
Debugger &debugger,
Target *target, // Can be NULL, if NULL create a new target, else use existing one
Listener &listener,
Error &error)
{
ProcessSP process_sp;
// Make sure we stop at the entry point
launch_info.GetFlags ().Set (eLaunchFlagDebug);
// We always launch the process we are going to debug in a separate process
// group, since then we can handle ^C interrupts ourselves w/o having to worry
// about the target getting them as well.
launch_info.SetLaunchInSeparateProcessGroup(true);
error = LaunchProcess (launch_info);
if (error.Success())
{
if (launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID)
{
ProcessAttachInfo attach_info (launch_info);
process_sp = Attach (attach_info, debugger, target, listener, error);
if (process_sp)
{
launch_info.SetHijackListener(attach_info.GetHijackListener());
// Since we attached to the process, it will think it needs to detach
// if the process object just goes away without an explicit call to
// Process::Kill() or Process::Detach(), so let it know to kill the
// process if this happens.
process_sp->SetShouldDetach (false);
// If we didn't have any file actions, the pseudo terminal might
// have been used where the slave side was given as the file to
// open for stdin/out/err after we have already opened the master
// so we can read/write stdin/out/err.
int pty_fd = launch_info.GetPTY().ReleaseMasterFileDescriptor();
if (pty_fd != lldb_utility::PseudoTerminal::invalid_fd)
{
process_sp->SetSTDIOFileDescriptor(pty_fd);
}
}
}
}
return process_sp;
}
ProcessSP PlatformWindows::DebugProcess(ProcessLaunchInfo &launch_info,
Debugger &debugger, Target *target,
Error &error) {
// Windows has special considerations that must be followed when launching or
// attaching to a process. The
// key requirement is that when launching or attaching to a process, you must
// do it from the same the thread
// that will go into a permanent loop which will then receive debug events
// from the process. In particular,
// this means we can't use any of LLDB's generic mechanisms to do it for us,
// because it doesn't have the
// special knowledge required for setting up the background thread or passing
// the right flags.
//
// Another problem is that that LLDB's standard model for debugging a process
// is to first launch it, have
// it stop at the entry point, and then attach to it. In Windows this doesn't
// quite work, you have to
// specify as an argument to CreateProcess() that you're going to debug the
// process. So we override DebugProcess
// here to handle this. Launch operations go directly to the process plugin,
// and attach operations almost go
// directly to the process plugin (but we hijack the events first). In
// essence, we encapsulate all the logic
// of Launching and Attaching in the process plugin, and
// PlatformWindows::DebugProcess is just a pass-through
// to get to the process plugin.
if (launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID) {
// This is a process attach. Don't need to launch anything.
ProcessAttachInfo attach_info(launch_info);
return Attach(attach_info, debugger, target, error);
} else {
ProcessSP process_sp =
target->CreateProcess(launch_info.GetListenerForProcess(debugger),
launch_info.GetProcessPluginName(), nullptr);
// We need to launch and attach to the process.
launch_info.GetFlags().Set(eLaunchFlagDebug);
if (process_sp)
error = process_sp->Launch(launch_info);
return process_sp;
}
}
Error
GDBRemoteCommunication::StartDebugserverProcess (const char *hostname,
uint16_t in_port,
ProcessLaunchInfo &launch_info,
uint16_t &out_port)
{
Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PROCESS));
if (log)
log->Printf ("GDBRemoteCommunication::%s(hostname=%s, in_port=%" PRIu16 ", out_port=%" PRIu16, __FUNCTION__, hostname ? hostname : "<empty>", in_port, out_port);
out_port = in_port;
Error error;
// If we locate debugserver, keep that located version around
static FileSpec g_debugserver_file_spec;
char debugserver_path[PATH_MAX];
FileSpec &debugserver_file_spec = launch_info.GetExecutableFile();
// Always check to see if we have an environment override for the path
// to the debugserver to use and use it if we do.
const char *env_debugserver_path = getenv("LLDB_DEBUGSERVER_PATH");
if (env_debugserver_path)
{
debugserver_file_spec.SetFile (env_debugserver_path, false);
if (log)
log->Printf ("GDBRemoteCommunication::%s() gdb-remote stub exe path set from environment variable: %s", __FUNCTION__, env_debugserver_path);
}
else
debugserver_file_spec = g_debugserver_file_spec;
bool debugserver_exists = debugserver_file_spec.Exists();
if (!debugserver_exists)
{
// The debugserver binary is in the LLDB.framework/Resources
// directory.
if (HostInfo::GetLLDBPath(ePathTypeSupportExecutableDir, debugserver_file_spec))
{
debugserver_file_spec.AppendPathComponent (DEBUGSERVER_BASENAME);
debugserver_exists = debugserver_file_spec.Exists();
if (debugserver_exists)
{
if (log)
log->Printf ("GDBRemoteCommunication::%s() found gdb-remote stub exe '%s'", __FUNCTION__, debugserver_file_spec.GetPath ().c_str ());
g_debugserver_file_spec = debugserver_file_spec;
}
else
{
if (log)
log->Printf ("GDBRemoteCommunication::%s() could not find gdb-remote stub exe '%s'", __FUNCTION__, debugserver_file_spec.GetPath ().c_str ());
g_debugserver_file_spec.Clear();
debugserver_file_spec.Clear();
}
}
}
if (debugserver_exists)
{
debugserver_file_spec.GetPath (debugserver_path, sizeof(debugserver_path));
Args &debugserver_args = launch_info.GetArguments();
debugserver_args.Clear();
char arg_cstr[PATH_MAX];
// Start args with "debugserver /file/path -r --"
debugserver_args.AppendArgument(debugserver_path);
#if !defined(__APPLE__)
// First argument to lldb-server must be mode in which to run.
debugserver_args.AppendArgument("gdbserver");
#endif
// If a host and port is supplied then use it
char host_and_port[128];
if (hostname)
{
snprintf (host_and_port, sizeof(host_and_port), "%s:%u", hostname, in_port);
debugserver_args.AppendArgument(host_and_port);
}
else
{
host_and_port[0] = '\0';
}
// use native registers, not the GDB registers
debugserver_args.AppendArgument("--native-regs");
if (launch_info.GetLaunchInSeparateProcessGroup())
{
debugserver_args.AppendArgument("--setsid");
}
llvm::SmallString<PATH_MAX> named_pipe_path;
Pipe port_pipe;
bool listen = false;
if (host_and_port[0])
{
// Create a temporary file to get the stdout/stderr and redirect the
// output of the command into this file. We will later read this file
// if all goes well and fill the data into "command_output_ptr"
if (in_port == 0)
{
// Binding to port zero, we need to figure out what port it ends up
// using using a named pipe...
error = port_pipe.CreateWithUniqueName("debugserver-named-pipe", false, named_pipe_path);
if (error.Success())
{
debugserver_args.AppendArgument("--named-pipe");
debugserver_args.AppendArgument(named_pipe_path.c_str());
}
else
{
if (log)
log->Printf("GDBRemoteCommunication::%s() "
"named pipe creation failed: %s",
__FUNCTION__, error.AsCString());
// let's try an unnamed pipe
error = port_pipe.CreateNew(true);
if (error.Fail())
{
if (log)
log->Printf("GDBRemoteCommunication::%s() "
"unnamed pipe creation failed: %s",
__FUNCTION__, error.AsCString());
return error;
}
int write_fd = port_pipe.GetWriteFileDescriptor();
debugserver_args.AppendArgument("--pipe");
debugserver_args.AppendArgument(std::to_string(write_fd).c_str());
launch_info.AppendCloseFileAction(port_pipe.GetReadFileDescriptor());
}
}
else
{
listen = true;
}
}
else
{
// No host and port given, so lets listen on our end and make the debugserver
// connect to us..
error = StartListenThread ("127.0.0.1", 0);
if (error.Fail())
return error;
ConnectionFileDescriptor *connection = (ConnectionFileDescriptor *)GetConnection ();
// Wait for 10 seconds to resolve the bound port
out_port = connection->GetListeningPort(10);
if (out_port > 0)
{
char port_cstr[32];
snprintf(port_cstr, sizeof(port_cstr), "127.0.0.1:%i", out_port);
// Send the host and port down that debugserver and specify an option
// so that it connects back to the port we are listening to in this process
debugserver_args.AppendArgument("--reverse-connect");
debugserver_args.AppendArgument(port_cstr);
}
else
{
error.SetErrorString ("failed to bind to port 0 on 127.0.0.1");
return error;
}
}
const char *env_debugserver_log_file = getenv("LLDB_DEBUGSERVER_LOG_FILE");
if (env_debugserver_log_file)
{
::snprintf (arg_cstr, sizeof(arg_cstr), "--log-file=%s", env_debugserver_log_file);
debugserver_args.AppendArgument(arg_cstr);
}
const char *env_debugserver_log_flags = getenv("LLDB_DEBUGSERVER_LOG_FLAGS");
if (env_debugserver_log_flags)
{
::snprintf (arg_cstr, sizeof(arg_cstr), "--log-flags=%s", env_debugserver_log_flags);
debugserver_args.AppendArgument(arg_cstr);
}
// Add additional args, starting with LLDB_DEBUGSERVER_EXTRA_ARG_1 until an env var doesn't come back.
uint32_t env_var_index = 1;
bool has_env_var;
do
{
char env_var_name[64];
snprintf (env_var_name, sizeof (env_var_name), "LLDB_DEBUGSERVER_EXTRA_ARG_%" PRIu32, env_var_index++);
const char *extra_arg = getenv(env_var_name);
has_env_var = extra_arg != nullptr;
if (has_env_var)
{
debugserver_args.AppendArgument (extra_arg);
if (log)
log->Printf ("GDBRemoteCommunication::%s adding env var %s contents to stub command line (%s)", __FUNCTION__, env_var_name, extra_arg);
}
} while (has_env_var);
// Close STDIN, STDOUT and STDERR.
launch_info.AppendCloseFileAction (STDIN_FILENO);
launch_info.AppendCloseFileAction (STDOUT_FILENO);
launch_info.AppendCloseFileAction (STDERR_FILENO);
// Redirect STDIN, STDOUT and STDERR to "/dev/null".
launch_info.AppendSuppressFileAction (STDIN_FILENO, true, false);
launch_info.AppendSuppressFileAction (STDOUT_FILENO, false, true);
launch_info.AppendSuppressFileAction (STDERR_FILENO, false, true);
error = Host::LaunchProcess(launch_info);
if (error.Success() && launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID)
{
if (named_pipe_path.size() > 0)
{
error = port_pipe.OpenAsReader(named_pipe_path, false);
if (error.Fail())
if (log)
log->Printf("GDBRemoteCommunication::%s() "
"failed to open named pipe %s for reading: %s",
__FUNCTION__, named_pipe_path.c_str(), error.AsCString());
}
if (port_pipe.CanWrite())
port_pipe.CloseWriteFileDescriptor();
if (port_pipe.CanRead())
{
char port_cstr[256];
port_cstr[0] = '\0';
size_t num_bytes = sizeof(port_cstr);
// Read port from pipe with 10 second timeout.
error = port_pipe.ReadWithTimeout(port_cstr, num_bytes,
std::chrono::seconds{10}, num_bytes);
if (error.Success())
{
assert(num_bytes > 0 && port_cstr[num_bytes-1] == '\0');
out_port = StringConvert::ToUInt32(port_cstr, 0);
if (log)
log->Printf("GDBRemoteCommunication::%s() "
"debugserver listens %u port",
__FUNCTION__, out_port);
}
else
{
if (log)
log->Printf("GDBRemoteCommunication::%s() "
"failed to read a port value from pipe %s: %s",
__FUNCTION__, named_pipe_path.c_str(), error.AsCString());
}
port_pipe.Close();
}
if (named_pipe_path.size() > 0)
{
const auto err = port_pipe.Delete(named_pipe_path);
if (err.Fail())
{
if (log)
log->Printf ("GDBRemoteCommunication::%s failed to delete pipe %s: %s",
__FUNCTION__, named_pipe_path.c_str(), err.AsCString());
}
}
// Make sure we actually connect with the debugserver...
JoinListenThread();
}
}
else
{
error.SetErrorStringWithFormat ("unable to locate " DEBUGSERVER_BASENAME );
}
return error;
}