Revert "[lldb] Implement basic support for reverse-continue (#99736)"

This reverts commit d5e1de6da96c1ab3b8cae68447e8ed3696a7006e.

12 files changed, 22 insertions, 121 deletions

diff --git a/lldb/source/Plugins/Process/Linux/NativeThreadLinux.cpp b/lldb/source/Plugins/Process/Linux/NativeThreadLinux.cpp
index b0aa664775b4..de047ee214c1 100644
--- a/lldb/source/Plugins/Process/Linux/NativeThreadLinux.cpp
+++ b/lldb/source/Plugins/Process/Linux/NativeThreadLinux.cpp
@@ -82,9 +82,6 @@ void LogThreadStopInfo(Log &log, const ThreadStopInfo &stop_info,
   case eStopReasonProcessorTrace:
     log.Printf("%s: %s processor trace", __FUNCTION__, header);
     return;
-  case eStopReasonHistoryBoundary:
-    log.Printf("%s: %s history boundary", __FUNCTION__, header);
-    return;
   default:
     log.Printf("%s: %s invalid stop reason %" PRIu32, __FUNCTION__, header,
                static_cast<uint32_t>(stop_info.reason));
diff --git a/lldb/source/Plugins/Process/MacOSX-Kernel/ProcessKDP.cpp b/lldb/source/Plugins/Process/MacOSX-Kernel/ProcessKDP.cpp
index 116c43343c01..9b2907c68099 100644
--- a/lldb/source/Plugins/Process/MacOSX-Kernel/ProcessKDP.cpp
+++ b/lldb/source/Plugins/Process/MacOSX-Kernel/ProcessKDP.cpp
@@ -402,16 +402,9 @@ lldb_private::DynamicLoader *ProcessKDP::GetDynamicLoader() {
 
 Status ProcessKDP::WillResume() { return Status(); }
 
-Status ProcessKDP::DoResume(RunDirection direction) {
+Status ProcessKDP::DoResume() {
   Status error;
   Log *log = GetLog(KDPLog::Process);
-
-  if (direction == RunDirection::eRunReverse) {
-    error.SetErrorStringWithFormatv(
-        "error: {0} does not support reverse execution of processes", GetPluginName());
-    return error;
-  }
-
   // Only start the async thread if we try to do any process control
   if (!m_async_thread.IsJoinable())
     StartAsyncThread();
diff --git a/lldb/source/Plugins/Process/MacOSX-Kernel/ProcessKDP.h b/lldb/source/Plugins/Process/MacOSX-Kernel/ProcessKDP.h
index 1b71d83f70b0..e5ec5914f960 100644
--- a/lldb/source/Plugins/Process/MacOSX-Kernel/ProcessKDP.h
+++ b/lldb/source/Plugins/Process/MacOSX-Kernel/ProcessKDP.h
@@ -90,7 +90,7 @@ public:
   // Process Control
   lldb_private::Status WillResume() override;
 
-  lldb_private::Status DoResume(lldb::RunDirection direction) override;
+  lldb_private::Status DoResume() override;
 
   lldb_private::Status DoHalt(bool &caused_stop) override;
 
diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp
index 76b7095deaa5..703aa082f047 100644
--- a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp
+++ b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.cpp
@@ -204,17 +204,11 @@ ProcessWindows::DoAttachToProcessWithID(lldb::pid_t pid,
   return error;
 }
 
-Status ProcessWindows::DoResume(RunDirection direction) {
+Status ProcessWindows::DoResume() {
   Log *log = GetLog(WindowsLog::Process);
   llvm::sys::ScopedLock lock(m_mutex);
   Status error;
 
-  if (direction == RunDirection::eRunReverse) {
-    error.SetErrorStringWithFormatv(
-        "error: {0} does not support reverse execution of processes", GetPluginName());
-    return error;
-  }
-
   StateType private_state = GetPrivateState();
   if (private_state == eStateStopped || private_state == eStateCrashed) {
     LLDB_LOG(log, "process {0} is in state {1}.  Resuming...",
diff --git a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.h b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.h
index 97284b7cd143..e97cfb790248 100644
--- a/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.h
+++ b/lldb/source/Plugins/Process/Windows/Common/ProcessWindows.h
@@ -52,7 +52,7 @@ public:
   Status DoAttachToProcessWithID(
       lldb::pid_t pid,
       const lldb_private::ProcessAttachInfo &attach_info) override;
-  Status DoResume(lldb::RunDirection direction) override;
+  Status DoResume() override;
   Status DoDestroy() override;
   Status DoHalt(bool &caused_stop) override;
 
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index fc792a440941..e42526c8fd72 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -199,20 +199,6 @@ uint64_t GDBRemoteCommunicationClient::GetRemoteMaxPacketSize() {
   return m_max_packet_size;
 }
 
-bool GDBRemoteCommunicationClient::GetReverseContinueSupported() {
-  if (m_supports_reverse_continue == eLazyBoolCalculate) {
-    GetRemoteQSupported();
-  }
-  return m_supports_reverse_continue == eLazyBoolYes;
-}
-
-bool GDBRemoteCommunicationClient::GetReverseStepSupported() {
-  if (m_supports_reverse_step == eLazyBoolCalculate) {
-    GetRemoteQSupported();
-  }
-  return m_supports_reverse_step == eLazyBoolYes;
-}
-
 bool GDBRemoteCommunicationClient::QueryNoAckModeSupported() {
   if (m_supports_not_sending_acks == eLazyBoolCalculate) {
     m_send_acks = true;
@@ -309,8 +295,6 @@ void GDBRemoteCommunicationClient::ResetDiscoverableSettings(bool did_exec) {
     m_supports_qXfer_siginfo_read = eLazyBoolCalculate;
     m_supports_augmented_libraries_svr4_read = eLazyBoolCalculate;
     m_uses_native_signals = eLazyBoolCalculate;
-    m_supports_reverse_continue = eLazyBoolCalculate;
-    m_supports_reverse_step = eLazyBoolCalculate;
     m_supports_qProcessInfoPID = true;
     m_supports_qfProcessInfo = true;
     m_supports_qUserName = true;
@@ -364,8 +348,6 @@ void GDBRemoteCommunicationClient::GetRemoteQSupported() {
   m_supports_memory_tagging = eLazyBoolNo;
   m_supports_qSaveCore = eLazyBoolNo;
   m_uses_native_signals = eLazyBoolNo;
-  m_supports_reverse_continue = eLazyBoolNo;
-  m_supports_reverse_step = eLazyBoolNo;
 
   m_max_packet_size = UINT64_MAX; // It's supposed to always be there, but if
                                   // not, we assume no limit
@@ -419,10 +401,6 @@ void GDBRemoteCommunicationClient::GetRemoteQSupported() {
         m_supports_qSaveCore = eLazyBoolYes;
       else if (x == "native-signals+")
         m_uses_native_signals = eLazyBoolYes;
-      else if (x == "ReverseContinue+")
-        m_supports_reverse_continue = eLazyBoolYes;
-      else if (x == "ReverseStep+")
-        m_supports_reverse_step = eLazyBoolYes;
       // Look for a list of compressions in the features list e.g.
       // qXfer:features:read+;PacketSize=20000;qEcho+;SupportedCompressions=zlib-
       // deflate,lzma
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
index 116b47c1edf0..898d176abc34 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
@@ -331,10 +331,6 @@ public:
 
   bool GetMultiprocessSupported();
 
-  bool GetReverseContinueSupported();
-
-  bool GetReverseStepSupported();
-
   LazyBool SupportsAllocDeallocMemory() // const
   {
     // Uncomment this to have lldb pretend the debug server doesn't respond to
@@ -565,8 +561,6 @@ protected:
   LazyBool m_supports_memory_tagging = eLazyBoolCalculate;
   LazyBool m_supports_qSaveCore = eLazyBoolCalculate;
   LazyBool m_uses_native_signals = eLazyBoolCalculate;
-  LazyBool m_supports_reverse_continue = eLazyBoolCalculate;
-  LazyBool m_supports_reverse_step = eLazyBoolCalculate;
 
   bool m_supports_qProcessInfoPID : 1, m_supports_qfProcessInfo : 1,
       m_supports_qUserName : 1, m_supports_qGroupName : 1,
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
index 4016cde74ebe..35fa93e53bc6 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -716,7 +716,6 @@ static const char *GetStopReasonString(StopReason stop_reason) {
     return "vforkdone";
   case eStopReasonInterrupt:
     return "async interrupt";
-  case eStopReasonHistoryBoundary:
   case eStopReasonInstrumentation:
   case eStopReasonInvalid:
   case eStopReasonPlanComplete:
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index 3fc03bd05d5d..3e09c316d74f 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -169,10 +169,6 @@ public:
   }
 };
 
-std::chrono::seconds ResumeTimeout() {
-  return std::chrono::seconds(5);
-}
-
 } // namespace
 
 static PluginProperties &GetGlobalPluginProperties() {
@@ -1184,11 +1180,10 @@ Status ProcessGDBRemote::WillResume() {
   return Status();
 }
 
-Status ProcessGDBRemote::DoResume(RunDirection direction) {
+Status ProcessGDBRemote::DoResume() {
   Status error;
   Log *log = GetLog(GDBRLog::Process);
-  LLDB_LOGF(log, "ProcessGDBRemote::Resume(%s)",
-            direction == RunDirection::eRunForward ? "" : "reverse");
+  LLDB_LOGF(log, "ProcessGDBRemote::Resume()");
 
   ListenerSP listener_sp(
       Listener::MakeListener("gdb-remote.resume-packet-sent"));
@@ -1202,21 +1197,12 @@ Status ProcessGDBRemote::DoResume(RunDirection direction) {
 
     StreamString continue_packet;
     bool continue_packet_error = false;
-    // Number of threads continuing with "c", i.e. continuing without a signal to deliver.
-    const size_t num_continue_c_tids = m_continue_c_tids.size();
-    // Number of threads continuing with "C", i.e. continuing with a signal to deliver.
-    const size_t num_continue_C_tids = m_continue_C_tids.size();
-    // Number of threads continuing with "s", i.e. single-stepping.
-    const size_t num_continue_s_tids = m_continue_s_tids.size();
-    // Number of threads continuing with "S", i.e. single-stepping with a signal to deliver.
-    const size_t num_continue_S_tids = m_continue_S_tids.size();
-    if (direction == RunDirection::eRunForward &&
-        m_gdb_comm.HasAnyVContSupport()) {
+    if (m_gdb_comm.HasAnyVContSupport()) {
       std::string pid_prefix;
       if (m_gdb_comm.GetMultiprocessSupported())
         pid_prefix = llvm::formatv("p{0:x-}.", GetID());
 
-      if (num_continue_c_tids == num_threads ||
+      if (m_continue_c_tids.size() == num_threads ||
           (m_continue_c_tids.empty() && m_continue_C_tids.empty() &&
            m_continue_s_tids.empty() && m_continue_S_tids.empty())) {
         // All threads are continuing
@@ -1279,11 +1265,14 @@ Status ProcessGDBRemote::DoResume(RunDirection direction) {
     } else
       continue_packet_error = true;
 
-    if (direction == RunDirection::eRunForward && continue_packet_error) {
+    if (continue_packet_error) {
       // Either no vCont support, or we tried to use part of the vCont packet
-      // that wasn't supported by the remote GDB server, or it's the reverse
-      // direction. We need to try and make a simple packet that can do our
-      // continue.
+      // that wasn't supported by the remote GDB server. We need to try and
+      // make a simple packet that can do our continue
+      const size_t num_continue_c_tids = m_continue_c_tids.size();
+      const size_t num_continue_C_tids = m_continue_C_tids.size();
+      const size_t num_continue_s_tids = m_continue_s_tids.size();
+      const size_t num_continue_S_tids = m_continue_S_tids.size();
       if (num_continue_c_tids > 0) {
         if (num_continue_c_tids == num_threads) {
           // All threads are resuming...
@@ -1374,41 +1363,9 @@ Status ProcessGDBRemote::DoResume(RunDirection direction) {
       }
     }
 
-    if (direction == RunDirection::eRunReverse && continue_packet_error) {
-      if (num_continue_C_tids > 0 || num_continue_S_tids > 0) {
-        LLDB_LOGF(log, "ProcessGDBRemote::DoResumeReverse: Signals not supported");
-        return Status::FromErrorString("can't deliver signals while running in reverse");
-      }
-
-      if (num_continue_s_tids > 0) {
-        if (num_continue_s_tids > 1) {
-          LLDB_LOGF(log, "ProcessGDBRemote::DoResumeReverse: can't step multiple threads");
-          return Status::FromErrorString("can't step multiple threads while reverse-stepping");
-        }
-
-        if (!m_gdb_comm.GetReverseStepSupported()) {
-          LLDB_LOGF(log, "ProcessGDBRemote::DoResumeReverse: target does not support reverse-stepping");
-          return Status::FromErrorString("target does not support reverse-stepping");
-        }
-
-        m_gdb_comm.SetCurrentThreadForRun(m_continue_s_tids.front());
-        continue_packet.PutCString("bs");
-      } else {
-        if (!m_gdb_comm.GetReverseContinueSupported()) {
-          LLDB_LOGF(log, "ProcessGDBRemote::DoResumeReverse: target does not support reverse-continue");
-          return Status::FromErrorString("target does not support reverse-continue");
-        }
-
-        // All threads continue whether requested or not ---
-        // we can't change how threads ran in the past.
-        continue_packet.PutCString("bc");
-      }
-
-      continue_packet_error = false;
-    }
-
     if (continue_packet_error) {
-      return Status::FromErrorString("can't make continue packet for this resume");
+      error =
+          Status::FromErrorString("can't make continue packet for this resume");
     } else {
       EventSP event_sp;
       if (!m_async_thread.IsJoinable()) {
@@ -1423,7 +1380,7 @@ Status ProcessGDBRemote::DoResume(RunDirection direction) {
           std::make_shared<EventDataBytes>(continue_packet.GetString());
       m_async_broadcaster.BroadcastEvent(eBroadcastBitAsyncContinue, data_sp);
 
-      if (!listener_sp->GetEvent(event_sp, ResumeTimeout())) {
+      if (!listener_sp->GetEvent(event_sp, std::chrono::seconds(5))) {
         error = Status::FromErrorString("Resume timed out.");
         LLDB_LOGF(log, "ProcessGDBRemote::DoResume: Resume timed out.");
       } else if (event_sp->BroadcasterIs(&m_async_broadcaster)) {
@@ -1906,10 +1863,6 @@ ThreadSP ProcessGDBRemote::SetThreadStopInfo(
           thread_sp->SetStopInfo(StopInfo::CreateStopReasonWithException(
               *thread_sp, description.c_str()));
           handled = true;
-        } else if (reason == "replaylog") {
-          thread_sp->SetStopInfo(StopInfo::CreateStopReasonHistoryBoundary(
-              *thread_sp, description.c_str()));
-          handled = true;
         } else if (reason == "exec") {
           did_exec = true;
           thread_sp->SetStopInfo(
@@ -2365,8 +2318,6 @@ StateType ProcessGDBRemote::SetThreadStopInfo(StringExtractor &stop_packet) {
         description = std::string(ostr.GetString());
       } else if (key.compare("swbreak") == 0 || key.compare("hwbreak") == 0) {
         reason = "breakpoint";
-      } else if (key.compare("replaylog") == 0) {
-        reason = "replaylog";
       } else if (key.compare("library") == 0) {
         auto error = LoadModules();
         if (error) {
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
index fa3e1cec76e2..249279585138 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.h
@@ -111,7 +111,7 @@ public:
   // Process Control
   Status WillResume() override;
 
-  Status DoResume(lldb::RunDirection direction) override;
+  Status DoResume() override;
 
   Status DoHalt(bool &caused_stop) override;
 
diff --git a/lldb/source/Plugins/Process/scripted/ScriptedProcess.cpp b/lldb/source/Plugins/Process/scripted/ScriptedProcess.cpp
index 304c12173dd3..d2111ce877ce 100644
--- a/lldb/source/Plugins/Process/scripted/ScriptedProcess.cpp
+++ b/lldb/source/Plugins/Process/scripted/ScriptedProcess.cpp
@@ -182,15 +182,10 @@ void ScriptedProcess::DidResume() {
   m_pid = GetInterface().GetProcessID();
 }
 
-Status ScriptedProcess::DoResume(RunDirection direction) {
+Status ScriptedProcess::DoResume() {
   LLDB_LOGF(GetLog(LLDBLog::Process), "ScriptedProcess::%s resuming process", __FUNCTION__);
 
-  if (direction == RunDirection::eRunForward) {
-    return GetInterface().Resume();
-  } else {
-    return Status::FromErrorStringWithFormatv(
-        "error: {0} does not support reverse execution of processes", GetPluginName());
-  }
+  return GetInterface().Resume();
 }
 
 Status ScriptedProcess::DoAttach(const ProcessAttachInfo &attach_info) {
diff --git a/lldb/source/Plugins/Process/scripted/ScriptedProcess.h b/lldb/source/Plugins/Process/scripted/ScriptedProcess.h
index 8ebe4ca5f3d4..0335364b4010 100644
--- a/lldb/source/Plugins/Process/scripted/ScriptedProcess.h
+++ b/lldb/source/Plugins/Process/scripted/ScriptedProcess.h
@@ -52,7 +52,7 @@ public:
 
   void DidResume() override;
 
-  Status DoResume(lldb::RunDirection direction) override;
+  Status DoResume() override;
 
   Status DoAttachToProcessWithID(lldb::pid_t pid,
                                  const ProcessAttachInfo &attach_info) override;