https://github.com/charles-zablit updated https://github.com/llvm/llvm-project/pull/201638
>From 488a6ce990aa489d73306795d3e40112a499bc9e Mon Sep 17 00:00:00 2001 From: Charles Zablit <[email protected]> Date: Thu, 4 Jun 2026 18:09:30 +0100 Subject: [PATCH 1/3] [lldb][Windows] add stdin support to lldb-server --- .../lldb/Host/common/NativeProcessProtocol.h | 6 ++++- .../Host/windows/ConnectionConPTYWindows.cpp | 27 ++++++++++++++++++- .../Windows/Common/NativeProcessWindows.cpp | 15 +++++++++++ .../Windows/Common/NativeProcessWindows.h | 7 +++++ .../Process/Windows/Common/ProcessWindows.cpp | 1 + .../GDBRemoteCommunicationServerLLGS.cpp | 9 ++++++- .../Process/gdb-remote/ProcessGDBRemote.cpp | 16 ++++++++++- 7 files changed, 77 insertions(+), 4 deletions(-) diff --git a/lldb/include/lldb/Host/common/NativeProcessProtocol.h b/lldb/include/lldb/Host/common/NativeProcessProtocol.h index 4e4804623b1d8..435185a38f3f9 100644 --- a/lldb/include/lldb/Host/common/NativeProcessProtocol.h +++ b/lldb/include/lldb/Host/common/NativeProcessProtocol.h @@ -247,8 +247,12 @@ class NativeProcessProtocol { // Access to inferior stdio virtual int GetTerminalFileDescriptor() { return m_terminal_fd; } - // Stop id interface + /// Write up to \p len bytes from \p buf to the inferior's stdin. + virtual size_t WriteStdin(const void *buf, size_t len, Status &error) { + return 0; + } + // Stop id interface uint32_t GetStopID() const; // Callbacks for low-level process state changes diff --git a/lldb/source/Host/windows/ConnectionConPTYWindows.cpp b/lldb/source/Host/windows/ConnectionConPTYWindows.cpp index e9d026fc7dc9f..f7e90421653e3 100644 --- a/lldb/source/Host/windows/ConnectionConPTYWindows.cpp +++ b/lldb/source/Host/windows/ConnectionConPTYWindows.cpp @@ -61,5 +61,30 @@ size_t ConnectionConPTY::Read(void *dst, size_t dst_len, size_t ConnectionConPTY::Write(const void *src, size_t src_len, lldb::ConnectionStatus &status, Status *error_ptr) { - llvm_unreachable("not implemented"); + if (!m_pty || !m_pty->IsConnected()) { + status = eConnectionStatusNoConnection; + if (error_ptr) + *error_ptr = Status::FromErrorString("ConPTY not connected"); + return 0; + } + HANDLE stdin_handle = m_pty->GetSTDINHandle(); + if (stdin_handle == INVALID_HANDLE_VALUE || stdin_handle == nullptr) { + status = eConnectionStatusNoConnection; + if (error_ptr) + *error_ptr = Status::FromErrorString("ConPTY STDIN handle is invalid"); + return 0; + } + DWORD written = 0; + if (!::WriteFile(stdin_handle, src, static_cast<DWORD>(src_len), &written, + nullptr)) { + DWORD err = ::GetLastError(); + status = (err == ERROR_BROKEN_PIPE || err == ERROR_NO_DATA) + ? eConnectionStatusEndOfFile + : eConnectionStatusError; + if (error_ptr) + *error_ptr = Status(err, lldb::eErrorTypeWin32); + return written; + } + status = eConnectionStatusSuccess; + return written; } diff --git a/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp b/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp index b235ab281bad6..bf447c9ea81f5 100644 --- a/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp +++ b/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp @@ -749,4 +749,19 @@ void NativeProcessWindows::STDIOReadThreadBytesReceived(void *baton, self->m_delegate.NewProcessOutput( self, llvm::StringRef(static_cast<const char *>(src), src_len)); } + +size_t NativeProcessWindows::WriteStdin(const void *buf, size_t len, + Status &error) { + if (!m_stdio_communication.HasConnection()) { + error = Status::FromErrorString( + "no ConPTY connection on this NativeProcessWindows"); + return 0; + } + ConnectionStatus status; + size_t written = m_stdio_communication.Write(buf, len, status, &error); + if (status != eConnectionStatusSuccess && error.Success()) + error = Status::FromErrorStringWithFormatv( + "ConPTY stdin write returned status {0}", static_cast<int>(status)); + return written; +} } // namespace lldb_private diff --git a/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.h b/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.h index 95b85754ebdeb..cac3920d82aa9 100644 --- a/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.h +++ b/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.h @@ -107,6 +107,13 @@ class NativeProcessWindows : public NativeProcessProtocol, bool HasPendingLibraryEvents() override; + /// Forward bytes from the gdb-remote `I` packet into the inferior's + /// ConPTY-backed stdin via `m_stdio_communication.Write` → + /// `ConnectionConPTY::Write` → `WriteFile` on the parent-side STDIN + /// HANDLE. Returns the number of bytes written (0 if the PTY is + /// disconnected or write fails). + size_t WriteStdin(const void *buf, size_t len, Status &error) override; + // ProcessDebugger Overrides void OnExitProcess(uint32_t exit_code) override; void OnDebuggerConnected(lldb::addr_t image_base) override; diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp index 941c25e9ecb77..d6776260806f3 100644 --- a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp +++ b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp @@ -46,6 +46,7 @@ #include "ForwardDecl.h" #include "IOHandlerProcessSTDIOWindows.h" #include "LocalDebugDelegate.h" +#include "Plugins/Process/Utility/IOHandlerProcessSTDIOWindows.h" #include "ProcessWindowsLog.h" #include "TargetThreadWindows.h" diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp index d56026e011564..077144f94227d 100644 --- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp +++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp @@ -2569,12 +2569,19 @@ GDBRemoteCommunicationServerLLGS::Handle_I(StringExtractorGDBRemote &packet) { // write directly to stdin *this might block if stdin buffer is full* // TODO: enqueue this block in circular buffer and send window size to // remote host - ConnectionStatus status; Status error; + +#if defined(_WIN32) + // On Windows the inferior's stdio is owned by NativeProcessWindows. + if (m_current_process->WriteStdin(tmp, read, error) != read || error.Fail()) + return SendErrorResponse(0x15); +#else + ConnectionStatus status; m_stdio_communication.WriteAll(tmp, read, status, &error); if (error.Fail()) { return SendErrorResponse(0x15); } +#endif } return SendOKResponse(); diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp index f6eaf5851338b..1cded3f428e0b 100644 --- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp +++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp @@ -95,6 +95,10 @@ #include "llvm/Support/Threading.h" #include "llvm/Support/raw_ostream.h" +#ifdef _WIN32 +#include "Plugins/Process/Windows/Common/IOHandlerProcessSTDIOWindows.h" +#endif + #if defined(__APPLE__) #define DEBUGSERVER_BASENAME "debugserver" #elif defined(_WIN32) @@ -873,8 +877,18 @@ Status ProcessGDBRemote::DoLaunch(lldb_private::Module *exe_module, SetPrivateState(SetThreadStopInfo(response)); if (!disable_stdio) { - if (pty.GetPrimaryFileDescriptor() != PseudoTerminal::invalid_fd) + if (pty.GetPrimaryFileDescriptor() != PseudoTerminal::invalid_fd) { SetSTDIOFileDescriptor(pty.ReleasePrimaryFileDescriptor()); + } +#ifdef _WIN32 + else if (m_stdin_forward) { + // No client-side PTY FD on Windows. + std::lock_guard<std::mutex> guard(m_process_input_reader_mutex); + if (!m_process_input_reader) + m_process_input_reader = + std::make_shared<IOHandlerProcessSTDIOWindows>(this); + } +#endif } } } else { >From 8ef86c815abf2be99d845bf47a9061c1837120c1 Mon Sep 17 00:00:00 2001 From: Charles Zablit <[email protected]> Date: Thu, 4 Jun 2026 18:10:57 +0100 Subject: [PATCH 2/3] [lldb][gdb-remote] Plumb interrupt_timeout through SendStdinNotification --- .../Process/gdb-remote/GDBRemoteCommunicationClient.cpp | 7 ++++--- .../Process/gdb-remote/GDBRemoteCommunicationClient.h | 9 ++++++++- .../Plugins/Process/gdb-remote/ProcessGDBRemote.cpp | 2 +- 3 files changed, 13 insertions(+), 5 deletions(-) diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp index 8df7936786b04..3a69a1d21f906 100644 --- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp +++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp @@ -1442,13 +1442,14 @@ bool GDBRemoteCommunicationClient::GetHostInfo(bool force) { return m_qHostInfo_is_valid == eLazyBoolYes; } -int GDBRemoteCommunicationClient::SendStdinNotification(const char *data, - size_t data_len) { +int GDBRemoteCommunicationClient::SendStdinNotification( + const char *data, size_t data_len, std::chrono::seconds interrupt_timeout) { StreamString packet; packet.PutCString("I"); packet.PutBytesAsRawHex8(data, data_len); StringExtractorGDBRemote response; - if (SendPacketAndWaitForResponse(packet.GetString(), response) == + if (SendPacketAndWaitForResponse(packet.GetString(), response, + interrupt_timeout) == PacketResult::Success) { return 0; } diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h index 79ca0bcd3ed22..384a7da4d06e4 100644 --- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h +++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h @@ -127,10 +127,17 @@ class GDBRemoteCommunicationClient : public GDBRemoteClientBase { /// \param[in] data_len /// The number of bytes available at \a data. /// + /// \param[in] interrupt_timeout + /// If the inferior is running, how long to wait for a `\x03` BREAK + /// to interrupt it before giving up. Pass zero (the default) only + /// when the caller knows the inferior is stopped. + /// /// \return /// Zero if the attach was successful, or an error indicating /// an error code. - int SendStdinNotification(const char *data, size_t data_len); + int SendStdinNotification( + const char *data, size_t data_len, + std::chrono::seconds interrupt_timeout = std::chrono::seconds(0)); /// Sets the path to use for stdin/out/err for a process /// that will be launched with the 'A' packet. diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp index 1cded3f428e0b..0114a8004d149 100644 --- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp +++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp @@ -3352,7 +3352,7 @@ size_t ProcessGDBRemote::PutSTDIN(const char *src, size_t src_len, ConnectionStatus status; m_stdio_communication.WriteAll(src, src_len, status, nullptr); } else if (m_stdin_forward) { - m_gdb_comm.SendStdinNotification(src, src_len); + m_gdb_comm.SendStdinNotification(src, src_len, GetInterruptTimeout()); } return 0; } >From 0dba3573a4c66c919df3ac5e93c9c241aee600b9 Mon Sep 17 00:00:00 2001 From: Charles Zablit <[email protected]> Date: Thu, 4 Jun 2026 18:12:21 +0100 Subject: [PATCH 3/3] [lldb][Windows] Surface DebugBreakProcess Halt() as a SIGSTOP signal stop --- .../Windows/Common/NativeProcessWindows.cpp | 36 +++++++++++++++++-- .../Windows/Common/NativeProcessWindows.h | 3 ++ 2 files changed, 37 insertions(+), 2 deletions(-) diff --git a/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp b/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp index bf447c9ea81f5..f0dc855457ac9 100644 --- a/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp +++ b/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp @@ -173,8 +173,13 @@ NativeProcessWindows::GetThreadByID(lldb::tid_t thread_id) { Status NativeProcessWindows::Halt() { bool caused_stop = false; StateType state = GetState(); - if (state != eStateStopped) - return HaltProcess(caused_stop); + if (state != eStateStopped) { + m_pending_halt = true; + Status err = HaltProcess(caused_stop); + if (err.Fail() || !caused_stop) + m_pending_halt = false; + return err; + } return Status(); } @@ -581,6 +586,33 @@ NativeProcessWindows::HandleBreakpointException(const ExceptionRecord &record) { // Any remaining STATUS_BREAKPOINT is a breakpoint instruction in the // program's own code (e.g. `__debugbreak()` or `__builtin_debugtrap()`). // Stop the debugger and let the user decide what to do. + if (m_pending_halt) { + LLDB_LOG(log, + "DebugBreakProcess injection treated as Halt SIGSTOP for tid " + "{0:x}", + thread_id); + m_pending_halt = false; + ThreadStopInfo signal_info; + signal_info.reason = StopReason::eStopReasonSignal; + signal_info.signo = 19; // SIGSTOP on POSIX + + // Halt all threads at the kernel level. + for (uint32_t i = 0; i < m_threads.size(); ++i) { + auto t = static_cast<NativeThreadWindows *>(m_threads[i].get()); + if (t->DoStop().Fail()) + exit(1); + } + if (!m_threads.empty()) { + auto first = static_cast<NativeThreadWindows *>(m_threads[0].get()); + first->SetStopReason(signal_info, "interrupt"); + } + SetCurrentThreadID(thread_id); + if (NativeThreadWindows *injected = GetThreadByID(thread_id)) + injected->SetStopReason(signal_info, "interrupt"); + SetState(eStateStopped, true); + return ExceptionResult::BreakInDebugger; + } + std::string desc = formatv("Exception {0:x8} encountered at address {1:x8}", record.GetExceptionCode(), exception_addr) .str(); diff --git a/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.h b/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.h index cac3920d82aa9..d1c57fc01e06b 100644 --- a/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.h +++ b/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.h @@ -167,6 +167,9 @@ class NativeProcessWindows : public NativeProcessProtocol, /// launch / attach. bool m_initial_stop_seen = false; + /// Set when Halt() / Interrupt() schedules a DebugBreakProcess injection. + bool m_pending_halt = false; + /// PseudoConsole for the lldb-server stdio-forwarding path. std::shared_ptr<PseudoConsole> m_pty; _______________________________________________ lldb-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
