1 //===-- GDBRemoteCommunication.h --------------------------------*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #ifndef LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATION_H
10 #define LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATION_H
12 #include "GDBRemoteCommunicationHistory.h"
14 #include <condition_variable>
20 #include "lldb/Core/Communication.h"
21 #include "lldb/Host/Config.h"
22 #include "lldb/Host/HostThread.h"
23 #include "lldb/Utility/Args.h"
24 #include "lldb/Utility/Listener.h"
25 #include "lldb/Utility/Predicate.h"
26 #include "lldb/Utility/StringExtractorGDBRemote.h"
27 #include "lldb/lldb-public.h"
29 namespace lldb_private {
33 namespace process_gdb_remote {
35 enum GDBStoppointType {
36 eStoppointInvalid = -1,
37 eBreakpointSoftware = 0,
44 enum class CompressionType {
45 None = 0, // no compression
46 ZlibDeflate, // zlib's deflate compression scheme, requires zlib or Apple's
48 LZFSE, // an Apple compression scheme, requires Apple's libcompression
49 LZ4, // lz compression - called "lz4 raw" in libcompression terms, compat with
50 // https://code.google.com/p/lz4/
51 LZMA, // Lempel–Ziv–Markov chain algorithm
54 class ProcessGDBRemote;
56 class GDBRemoteCommunication : public Communication {
59 eBroadcastBitRunPacketSent = kLoUserBroadcastBit,
60 eBroadcastBitGdbReadThreadGotNotify =
61 kLoUserBroadcastBit << 1 // Sent when we received a notify packet.
64 enum class PacketType { Invalid = 0, Standard, Notify };
66 enum class PacketResult {
67 Success = 0, // Success
68 ErrorSendFailed, // Status sending the packet
69 ErrorSendAck, // Didn't get an ack back after sending a packet
70 ErrorReplyFailed, // Status getting the reply
71 ErrorReplyTimeout, // Timed out waiting for reply
72 ErrorReplyInvalid, // Got a reply but it wasn't valid for the packet that
74 ErrorReplyAck, // Sending reply ack failed
75 ErrorDisconnected, // We were disconnected
76 ErrorNoSequenceLock // We couldn't get the sequence lock for a multi-packet
80 // Class to change the timeout for a given scope and restore it to the
81 // original value when the
82 // created ScopedTimeout object got out of scope
85 ScopedTimeout(GDBRemoteCommunication &gdb_comm,
86 std::chrono::seconds timeout);
90 GDBRemoteCommunication &m_gdb_comm;
91 std::chrono::seconds m_saved_timeout;
92 // Don't ever reduce the timeout for a packet, only increase it. If the
93 // requested timeout if less than the current timeout, we don't set it
94 // and won't need to restore it.
95 bool m_timeout_modified;
98 GDBRemoteCommunication(const char *comm_name, const char *listener_name);
100 ~GDBRemoteCommunication() override;
102 PacketResult GetAck();
108 char CalculcateChecksum(llvm::StringRef payload);
110 PacketType CheckForPacket(const uint8_t *src, size_t src_len,
111 StringExtractorGDBRemote &packet);
113 bool GetSendAcks() { return m_send_acks; }
115 // Set the global packet timeout.
117 // For clients, this is the timeout that gets used when sending
118 // packets and waiting for responses. For servers, this is used when waiting
120 std::chrono::seconds SetPacketTimeout(std::chrono::seconds packet_timeout) {
121 const auto old_packet_timeout = m_packet_timeout;
122 m_packet_timeout = packet_timeout;
123 return old_packet_timeout;
126 std::chrono::seconds GetPacketTimeout() const { return m_packet_timeout; }
128 // Start a debugserver instance on the current host using the
129 // supplied connection URL.
130 Status StartDebugserverProcess(
132 Platform *platform, // If non nullptr, then check with the platform for
133 // the GDB server binary if it can't be located
134 ProcessLaunchInfo &launch_info, uint16_t *port, const Args *inferior_args,
135 int pass_comm_fd); // Communication file descriptor to pass during
136 // fork/exec to avoid having to connect/accept
138 void DumpHistory(Stream &strm);
140 void SetPacketRecorder(repro::PacketRecorder *recorder);
142 static llvm::Error ConnectLocally(GDBRemoteCommunication &client,
143 GDBRemoteCommunication &server);
145 /// Expand GDB run-length encoding.
146 static std::string ExpandRLE(std::string);
149 std::chrono::seconds m_packet_timeout;
150 uint32_t m_echo_number;
151 LazyBool m_supports_qEcho;
152 GDBRemoteCommunicationHistory m_history;
154 bool m_is_platform; // Set to true if this class represents a platform,
155 // false if this class represents a debug session for
158 CompressionType m_compression_type;
160 PacketResult SendPacketNoLock(llvm::StringRef payload);
161 PacketResult SendRawPacketNoLock(llvm::StringRef payload,
162 bool skip_ack = false);
164 PacketResult ReadPacket(StringExtractorGDBRemote &response,
165 Timeout<std::micro> timeout, bool sync_on_timeout);
167 PacketResult ReadPacketWithOutputSupport(
168 StringExtractorGDBRemote &response, Timeout<std::micro> timeout,
169 bool sync_on_timeout,
170 llvm::function_ref<void(llvm::StringRef)> output_callback);
172 // Pop a packet from the queue in a thread safe manner
173 PacketResult PopPacketFromQueue(StringExtractorGDBRemote &response,
174 Timeout<std::micro> timeout);
176 PacketResult WaitForPacketNoLock(StringExtractorGDBRemote &response,
177 Timeout<std::micro> timeout,
178 bool sync_on_timeout);
180 bool CompressionIsEnabled() {
181 return m_compression_type != CompressionType::None;
184 // If compression is enabled, decompress the packet in m_bytes and update
185 // m_bytes with the uncompressed version.
186 // Returns 'true' packet was decompressed and m_bytes is the now-decompressed
188 // Returns 'false' if unable to decompress or if the checksum was invalid.
190 // NB: Once the packet has been decompressed, checksum cannot be computed
192 // on m_bytes. The checksum was for the compressed packet.
193 bool DecompressPacket();
195 Status StartListenThread(const char *hostname = "127.0.0.1",
198 bool JoinListenThread();
200 static lldb::thread_result_t ListenThread(lldb::thread_arg_t arg);
202 // GDB-Remote read thread
203 // . this thread constantly tries to read from the communication
204 // class and stores all packets received in a queue. The usual
205 // threads read requests simply pop packets off the queue in the
207 // This setup allows us to intercept and handle async packets, such
208 // as the notify packet.
210 // This method is defined as part of communication.h
211 // when the read thread gets any bytes it will pass them on to this function
212 void AppendBytesToCache(const uint8_t *bytes, size_t len, bool broadcast,
213 lldb::ConnectionStatus status) override;
216 std::queue<StringExtractorGDBRemote> m_packet_queue; // The packet queue
217 std::mutex m_packet_queue_mutex; // Mutex for accessing queue
218 std::condition_variable
219 m_condition_queue_not_empty; // Condition variable to wait for packets
221 HostThread m_listen_thread;
222 std::string m_listen_url;
224 #if defined(HAVE_LIBCOMPRESSION)
225 CompressionType m_decompression_scratch_type = CompressionType::None;
226 void *m_decompression_scratch = nullptr;
229 GDBRemoteCommunication(const GDBRemoteCommunication &) = delete;
230 const GDBRemoteCommunication &
231 operator=(const GDBRemoteCommunication &) = delete;
234 } // namespace process_gdb_remote
235 } // namespace lldb_private
239 struct format_provider<
240 lldb_private::process_gdb_remote::GDBRemoteCommunication::PacketResult> {
241 static void format(const lldb_private::process_gdb_remote::
242 GDBRemoteCommunication::PacketResult &state,
243 raw_ostream &Stream, StringRef Style);
247 #endif // LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATION_H