[Lldb-commits] [PATCH] D70742: [LLDB] [Windows] Avoid using InitializeContext for allocating a CONTEXT. NFC.

[Martin Storsjö via Phabricator via lldb-commits]

mstorsjo created this revision.
mstorsjo added reviewers: labath, amccarth, asmith, aleksandr.urakov.
Herald added a project: LLDB.

InitializeContext is useful for allocating a CONTEXT struct in an unaligned byte buffer. In this case, we already have a CONTEXT we want to initialize, and we only used this as a very roundabout way of zero initializing it.

Instead just memset the CONTEXT we have, and set the ContextFlags field manually.

This matches how it is done in NativeRegisterContextWindows_*.cpp.

This also makes LLDB run successfully in Wine (for a trivial tested case at least), as Wine haven't implemented the InitializeContext function.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D70742

Files:
  lldb/source/Plugins/Process/Windows/Common/RegisterContextWindows.cpp


Index: lldb/source/Plugins/Process/Windows/Common/RegisterContextWindows.cpp
===================================================================
--- lldb/source/Plugins/Process/Windows/Common/RegisterContextWindows.cpp
+++ lldb/source/Plugins/Process/Windows/Common/RegisterContextWindows.cpp
@@ -154,15 +154,8 @@
     return true;
 
   TargetThreadWindows &wthread = static_cast<TargetThreadWindows &>(m_thread);
-  uint8_t buffer[2048];
-  memset(buffer, 0, sizeof(buffer));
-  PCONTEXT tmpContext = NULL;
-  DWORD contextLength = (DWORD)sizeof(buffer);
-  if (!::InitializeContext(buffer, kWinContextFlags, &tmpContext,
-                           &contextLength)) {
-    return false;
-  }
-  memcpy(&m_context, tmpContext, sizeof(m_context));
+  memset(&m_context, 0, sizeof(m_context));
+  m_context.ContextFlags = kWinContextFlags;
   if (::SuspendThread(
           wthread.GetHostThread().GetNativeThread().GetSystemHandle()) ==
       (DWORD)-1) {


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