[Lldb-commits] [lldb] 79fa36f - [lldb][Windows] Invalidate cached register values on thread stop (#192430)

[via lldb-commits]

Author: Ayush Sahay
Date: 2026-05-10T18:30:18+05:30
New Revision: 79fa36f9ceeb325b4c946a5a52b3c8775d7e7ddd

URL: https://github.com/llvm/llvm-project/commit/79fa36f9ceeb325b4c946a5a52b3c8775d7e7ddd
DIFF: https://github.com/llvm/llvm-project/commit/79fa36f9ceeb325b4c946a5a52b3c8775d7e7ddd.diff

LOG: [lldb][Windows] Invalidate cached register values on thread stop (#192430)

Invalidate cached values in register context data structures on every
thread stop.

NativeRegisterContextRegisterInfo::InvalidateAllRegisters performs no
operation by default. Subclasses may override it to clear cached values
within their register context data structures whenever a thread stops.

This change intends to set up the necessary infrastructure to support
caching of the thread context in NativeRegisterContextWindows_arm64,
which will improve read performance. Currently, the thread context is
retrieved for every read or write operation.

Added: 
    

Modified: 
    lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux.h
    lldb/source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h
    lldb/source/Plugins/Process/Windows/Common/NativeThreadWindows.cpp

Removed: 
    


################################################################################
diff  --git a/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux.h b/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux.h
index 08f19d374e280..797eacc3bdd0f 100644
--- a/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux.h
+++ b/lldb/source/Plugins/Process/Linux/NativeRegisterContextLinux.h
@@ -37,9 +37,6 @@ class NativeRegisterContextLinux
   // Determine the architecture of the thread given by its ID.
   static llvm::Expected<ArchSpec> DetermineArchitecture(lldb::tid_t tid);
 
-  // Invalidates cached values in register context data structures
-  virtual void InvalidateAllRegisters(){}
-
   struct SyscallData {
     /// The syscall instruction. If the architecture uses software
     /// single-stepping, the instruction should also be followed by a trap to

diff  --git a/lldb/source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h b/lldb/source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h
index 0e96841fd9091..58a2a4843e4ec 100644
--- a/lldb/source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h
+++ b/lldb/source/Plugins/Process/Utility/NativeRegisterContextRegisterInfo.h
@@ -33,6 +33,9 @@ class NativeRegisterContextRegisterInfo : public NativeRegisterContext {
 
   const RegisterInfoInterface &GetRegisterInfoInterface() const;
 
+  // Invalidate cached values in register context data structures.
+  virtual void InvalidateAllRegisters() {}
+
 protected:
   std::unique_ptr<RegisterInfoInterface> m_register_info_interface_up;
 };

diff  --git a/lldb/source/Plugins/Process/Windows/Common/NativeThreadWindows.cpp b/lldb/source/Plugins/Process/Windows/Common/NativeThreadWindows.cpp
index 8ad59cd1ece88..d76e9a51fdace 100644
--- a/lldb/source/Plugins/Process/Windows/Common/NativeThreadWindows.cpp
+++ b/lldb/source/Plugins/Process/Windows/Common/NativeThreadWindows.cpp
@@ -38,6 +38,9 @@ Status NativeThreadWindows::DoStop() {
     if (previous_suspend_count == (DWORD)-1)
       return Status(::GetLastError(), eErrorTypeWin32);
 
+    // Invalidate cached register values on every stop.
+    GetRegisterContext().InvalidateAllRegisters();
+
     m_state = eStateStopped;
   }
   return Status();