Use FILE_FLAG_DELETE_ON_CLOSE for TempFile on windows.
We won't see the temp file no more.
llvm-svn: 319137
diff --git a/llvm/lib/Support/Windows/Path.inc b/llvm/lib/Support/Windows/Path.inc
index 113f259..f5b1c0f 100644
--- a/llvm/lib/Support/Windows/Path.inc
+++ b/llvm/lib/Support/Windows/Path.inc
@@ -391,6 +391,53 @@
return is_local_internal(FinalPath, Result);
}
+/// In order to handle temporary files we want the following properties
+///
+/// * The temporary file is deleted on crashes
+/// * We can use (read, rename, etc) the temporary file.
+/// * We can cancel the delete to keep the file.
+///
+/// Using FILE_DISPOSITION_INFO with DeleteFile=true will create a file that is
+/// deleted on close, but it has a few problems:
+///
+/// * The file cannot be used. An attempt to open or rename the file will fail.
+/// This makes the temporary file almost useless, as it cannot be part of
+/// any other CreateFileW call in the current or in another process.
+/// * It is not atomic. A crash just after CreateFileW or just after canceling
+/// the delete will leave the file on disk.
+///
+/// Using FILE_FLAG_DELETE_ON_CLOSE solves the first issues and the first part
+/// of the second one, but there is no way to cancel it in place. What works is
+/// to create a second handle to prevent the deletion, close the first one and
+/// then clear DeleteFile with SetFileInformationByHandle. This requires
+/// changing the handle and file descriptor the caller uses.
+static std::error_code cancelDeleteOnClose(int &FD) {
+ HANDLE Handle = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
+ SmallVector<wchar_t, MAX_PATH> Name;
+ if (std::error_code EC = realPathFromHandle(Handle, Name))
+ return EC;
+ HANDLE NewHandle =
+ ::CreateFileW(Name.data(), GENERIC_READ | GENERIC_WRITE | DELETE,
+ FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+ NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+ if (NewHandle == INVALID_HANDLE_VALUE)
+ return mapWindowsError(::GetLastError());
+ if (close(FD))
+ return mapWindowsError(::GetLastError());
+
+ FILE_DISPOSITION_INFO Disposition;
+ Disposition.DeleteFile = false;
+ if (!SetFileInformationByHandle(NewHandle, FileDispositionInfo, &Disposition,
+ sizeof(Disposition)))
+ return mapWindowsError(::GetLastError());
+ FD = ::_open_osfhandle(intptr_t(NewHandle), 0);
+ if (FD == -1) {
+ ::CloseHandle(NewHandle);
+ return mapWindowsError(ERROR_INVALID_HANDLE);
+ }
+ return std::error_code();
+}
+
static std::error_code rename_internal(HANDLE FromHandle, const Twine &To,
bool ReplaceIfExists) {
SmallVector<wchar_t, 0> ToWide;
@@ -513,6 +560,11 @@
return errc::permission_denied;
}
+static std::error_code rename_fd(int FromFD, const Twine &To) {
+ HANDLE FromHandle = reinterpret_cast<HANDLE>(_get_osfhandle(FromFD));
+ return rename_handle(FromHandle, To);
+}
+
std::error_code rename(const Twine &From, const Twine &To) {
// Convert to utf-16.
SmallVector<wchar_t, 128> WideFrom;
@@ -1029,15 +1081,18 @@
CreationDisposition = CREATE_ALWAYS;
DWORD Access = GENERIC_WRITE;
+ DWORD Attributes = FILE_ATTRIBUTE_NORMAL;
if (Flags & F_RW)
Access |= GENERIC_READ;
- if (Flags & F_Delete)
+ if (Flags & F_Delete) {
Access |= DELETE;
+ Attributes |= FILE_FLAG_DELETE_ON_CLOSE;
+ }
HANDLE H =
- ::CreateFileW(PathUTF16.begin(), Access,
+ ::CreateFileW(PathUTF16.data(), Access,
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
- NULL, CreationDisposition, FILE_ATTRIBUTE_NORMAL, NULL);
+ NULL, CreationDisposition, Attributes, NULL);
if (H == INVALID_HANDLE_VALUE) {
DWORD LastError = ::GetLastError();