Remove HW breakpoint support

Author: omjavaid

lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp

@@ -491,42 +491,32 @@ NativeProcessWindows::OnDebugException(bool first_chance,
     return ExceptionResult::MaskException;
   }
   case DWORD(STATUS_BREAKPOINT):
-  case STATUS_WX86_BREAKPOINT: {
-    bool breakpoint_hit = false;
-    NativeThreadWindows *stop_thread = GetThreadByID(record.GetThreadID());
+  case STATUS_WX86_BREAKPOINT:
 
-    if (stop_thread) {
-      uint32_t hw_id = LLDB_INVALID_INDEX32;
+    if (NativeThreadWindows *stop_thread =
+            GetThreadByID(record.GetThreadID())) {
       auto &reg_ctx = stop_thread->GetRegisterContext();
-      reg_ctx.GetHardwareBreakHitIndex(hw_id, record.GetExceptionAddress());
-      if (hw_id != LLDB_INVALID_INDEX32) {
-        breakpoint_hit = true;
-        LLDB_LOG(log, "Hit hardware breakpoint at address {0:x}.",
-                 record.GetExceptionAddress());
-      } else if (FindSoftwareBreakpoint(record.GetExceptionAddress())) {
-        breakpoint_hit = true;
+      const auto exception_addr = record.GetExceptionAddress();
+      const auto thread_id = record.GetThreadID();
+
+      if (FindSoftwareBreakpoint(exception_addr)) {
         LLDB_LOG(log, "Hit non-loader breakpoint at address {0:x}.",
-                 record.GetExceptionAddress());
-        uint32_t breakpoint_size = GetSoftwareBreakpointPCOffset();
-        // The current PC is AFTER the BP opcode, on all architectures.
-        uint64_t pc = reg_ctx.GetPC() - breakpoint_size;
-        reg_ctx.SetPC(pc);
-      }
+                 exception_addr);
 
-      if (breakpoint_hit) {
-        StopThread(record.GetThreadID(), StopReason::eStopReasonBreakpoint);
+        reg_ctx.SetPC(reg_ctx.GetPC() - GetSoftwareBreakpointPCOffset());
+        StopThread(thread_id, StopReason::eStopReasonBreakpoint);
         SetState(eStateStopped, true);
         return ExceptionResult::MaskException;
       } else {
         const std::vector<ULONG_PTR> &args = record.GetExceptionArguments();
         if (args.size() >= 2) {
+          uint32_t hw_id = LLDB_INVALID_INDEX32;
           reg_ctx.GetWatchpointHitIndex(hw_id, args[1]);
+
           if (hw_id != LLDB_INVALID_INDEX32) {
-            addr_t wp_pc = record.GetExceptionAddress();
             std::string desc =
-                formatv("{0} {1} {2}", args[1], hw_id, wp_pc).str();
-            StopThread(record.GetThreadID(), StopReason::eStopReasonWatchpoint,
-                       desc);
+                formatv("{0} {1} {2}", args[1], hw_id, exception_addr).str();
+            StopThread(thread_id, StopReason::eStopReasonWatchpoint, desc);
             SetState(eStateStopped, true);
             return ExceptionResult::MaskException;
           }
@@ -554,7 +544,6 @@ NativeProcessWindows::OnDebugException(bool first_chance,
       // Hit the initial stop. Continue the application.
       return ExceptionResult::BreakInDebugger;
     }
-  }
 
     [[fallthrough]];
   default:

lldb/source/Plugins/Process/Windows/Common/NativeRegisterContextWindows_arm64.cpp

@@ -147,8 +147,8 @@ NativeRegisterContextWindows_arm64::NativeRegisterContextWindows_arm64(
   // Currently, there is no API to query the maximum supported hardware
   // breakpoints and watchpoints on Windows. The values set below are based
   // on tests conducted on Windows 11 with Snapdragon Elite X hardware.
-  m_max_hwp_supported = 1;
-  m_max_hbp_supported = 6;
+  m_max_hwp_supported = 2;
+  m_max_hbp_supported = 0;
 }
 
 bool NativeRegisterContextWindows_arm64::IsGPR(uint32_t reg_index) const {
@@ -726,10 +726,6 @@ llvm::Error NativeRegisterContextWindows_arm64::ReadHardwareDebugInfo() {
     m_hwp_regs[i].control = tls_context.Wcr[i];
   }
 
-  for (uint32_t i = 0; i < m_max_hbp_supported; i++) {
-    m_hbp_regs[i].address = tls_context.Bvr[i];
-    m_hbp_regs[i].control = tls_context.Bcr[i];
-  }
   return llvm::Error::success();
 }
 
@@ -741,19 +737,11 @@ NativeRegisterContextWindows_arm64::WriteHardwareDebugRegs(DREGType hwbType) {
   if (error.Fail())
     return error.ToError();
 
-  switch (hwbType) {
-  case eDREGTypeWATCH:
+  if (hwbType == eDREGTypeWATCH) {
     for (uint32_t i = 0; i < m_max_hwp_supported; i++) {
       tls_context.Wvr[i] = m_hwp_regs[i].address;
       tls_context.Wcr[i] = m_hwp_regs[i].control;
     }
-    break;
-  case eDREGTypeBREAK:
-    for (uint32_t i = 0; i < m_max_hbp_supported; i++) {
-      tls_context.Bvr[i] = m_hbp_regs[i].address;
-      tls_context.Bcr[i] = m_hbp_regs[i].control;
-    }
-    break;
   }
 
   return SetThreadContextHelper(GetThreadHandle(), &tls_context).ToError();

lldb/source/Plugins/Process/Windows/Common/NativeThreadWindows.cpp

@@ -178,41 +178,9 @@ Status NativeThreadWindows::RemoveWatchpoint(lldb::addr_t addr) {
 
 Status NativeThreadWindows::SetHardwareBreakpoint(lldb::addr_t addr,
                                                   size_t size) {
-#if defined(__aarch64__) || defined(_M_ARM64)
-  if (m_state == eStateLaunching)
-    return Status();
-
-  Status error = RemoveHardwareBreakpoint(addr);
-  if (error.Fail())
-    return error;
-
-  uint32_t bp_index = m_reg_context_up->SetHardwareBreakpoint(addr, size);
-
-  if (bp_index == LLDB_INVALID_INDEX32)
-    return Status::FromErrorString("Setting hardware breakpoint failed.");
-
-  m_hw_breakpoint_index_map.insert({addr, bp_index});
-
-  return Status();
-#else
   return Status::FromErrorString("unimplemented.");
-#endif
 }
 
 Status NativeThreadWindows::RemoveHardwareBreakpoint(lldb::addr_t addr) {
-#if defined(__aarch64__) || defined(_M_ARM64)
-  auto bp = m_hw_breakpoint_index_map.find(addr);
-  if (bp == m_hw_breakpoint_index_map.end())
-    return Status();
-
-  uint32_t bp_index = bp->second;
-  if (m_reg_context_up->ClearHardwareBreakpoint(bp_index)) {
-    m_hw_breakpoint_index_map.erase(bp);
-    return Status();
-  }
-
-  return Status::FromErrorString("Clearing hardware breakpoint failed.");
-#else
   return Status::FromErrorString("unimplemented.");
-#endif
 }