llvm-project/lldb/source/Host/windows/ThisThread.cpp

//===-- ThisThread.cpp ------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "lldb/Core/Error.h"

#include "lldb/Host/windows/windows.h"
#include "lldb/Host/ThisThread.h"

#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"

using namespace lldb;
using namespace lldb_private;

#if defined(_MSC_VER) && !defined(__clang__)

namespace
{
static const DWORD MS_VC_EXCEPTION = 0x406D1388;

#pragma pack(push, 8)
struct THREADNAME_INFO
{
    DWORD dwType;     // Must be 0x1000.
    LPCSTR szName;    // Pointer to thread name
    DWORD dwThreadId; // Thread ID (-1 == current thread)
    DWORD dwFlags;    // Reserved.  Do not use.
};
#pragma pack(pop)
}

#endif

void
ThisThread::SetName(llvm::StringRef name)
{
// Other compilers don't yet support SEH, so we can only set the thread if compiling with MSVC.
// TODO(zturner): Once clang-cl supports SEH, relax this conditional.
#if defined(_MSC_VER) && !defined(__clang__)
    THREADNAME_INFO info;
    info.dwType = 0x1000;
    info.szName = name.data();
    info.dwThreadId = ::GetCurrentThreadId();
    info.dwFlags = 0;

    __try {
        ::RaiseException(MS_VC_EXCEPTION, 0, sizeof(info) / sizeof(ULONG_PTR), (ULONG_PTR *)&info);
    }
    __except(EXCEPTION_EXECUTE_HANDLER) {}
#endif
}

void
ThisThread::GetName(llvm::SmallVectorImpl<char> &name)
{
    // Getting the thread name is not supported on Windows.
    // TODO(zturner): In SetName(), make a TLS entry that contains the thread's name, and in this function
    // try to extract that TLS entry.
    name.clear();
}