Commit 344bdeb7 authored by Martin Storsjö's avatar Martin Storsjö
Browse files

[LLDB] Avoid using InitializeContext for zero-initializing a CONTEXT. NFC. 

InitializeContext is useful for allocating a (potentially variable
size) CONTEXT struct in an unaligned byte buffer. In this case, we
already have a fixed size 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 hasn't implemented the InitializeContext
function.

Differential Revision: https://reviews.llvm.org/D70742
parent 3a280422

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

+2 −9
Original line number Diff line number Diff line
@@ -154,15 +154,8 @@ bool RegisterContextWindows::CacheAllRegisterValues() { 
    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) {