[wpiutil] Change kInvalidFile to macro (#7750)

This is needed on Windows because accessing global variables across shared library boundaries doesn’t work.

wpiutil/src/main/native/cpp/DataLogBackgroundWriter.cpp

@@ -183,9 +183,9 @@ struct DataLogBackgroundWriter::WriterThreadState {
   ~WriterThreadState() { Close(); }
 
   void Close() {
-    if (f != fs::kInvalidFile) {
+    if (f != WPI_kInvalidFile) {
       fs::CloseFile(f);
-      f = fs::kInvalidFile;
+      f = WPI_kInvalidFile;
     }
   }
 
@@ -207,7 +207,7 @@ struct DataLogBackgroundWriter::WriterThreadState {
   std::string baseFilename;
   std::string filename;
   fs::path path;
-  fs::file_t f = fs::kInvalidFile;
+  fs::file_t f = WPI_kInvalidFile;
   uintmax_t freeSpace = UINTMAX_MAX;
   int segmentCount = 1;
 };
@@ -264,7 +264,7 @@ void DataLogBackgroundWriter::StartLogFile(WriterThreadState& state) {
       }
     }
 
-    if (state.f == fs::kInvalidFile) {
+    if (state.f == WPI_kInvalidFile) {
       WPI_ERROR(m_msglog, "Could not open log file, no log being saved");
     } else {
       WPI_INFO(m_msglog, "Logging to '{}' ({} free space)", state.path.string(),
@@ -273,7 +273,7 @@ void DataLogBackgroundWriter::StartLogFile(WriterThreadState& state) {
   }
 
   // start file
-  if (state.f != fs::kInvalidFile) {
+  if (state.f != WPI_kInvalidFile) {
     StartFile();
   }
 }
@@ -347,7 +347,7 @@ void DataLogBackgroundWriter::WriterThreadMain(std::string_view dir) {
       written = 0;
     }
 
-    if (!m_newFilename.empty() && state.f != fs::kInvalidFile) {
+    if (!m_newFilename.empty() && state.f != WPI_kInvalidFile) {
       auto newFilename = std::move(m_newFilename);
       m_newFilename.clear();
       // rename
@@ -374,7 +374,7 @@ void DataLogBackgroundWriter::WriterThreadMain(std::string_view dir) {
         continue;
       }
 
-      if (state.f != fs::kInvalidFile && !blocked) {
+      if (state.f != WPI_kInvalidFile && !blocked) {
         lock.unlock();
 
         // update free space every 10 flushes (in case other things are writing)

wpiutil/src/main/native/cpp/fs.cpp

@@ -59,8 +59,6 @@ namespace fs {
 #pragma warning(disable : 4244 4267 4146)
 #endif
 
-const file_t kInvalidFile = INVALID_HANDLE_VALUE;
-
 static DWORD nativeDisposition(CreationDisposition Disp, OpenFlags Flags) {
   switch (Disp) {
     case CD_CreateAlways:
@@ -107,12 +105,12 @@ static file_t openFileInternal(const path& Path, std::error_code& EC,
     // This only runs if we failed to open the file, so there is probably
     // no performances issues.
     if (LastError != ERROR_ACCESS_DENIED) {
-      return kInvalidFile;
+      return WPI_kInvalidFile;
     }
     if (is_directory(Path)) {
       EC = std::make_error_code(std::errc::is_a_directory);
     }
-    return kInvalidFile;
+    return WPI_kInvalidFile;
   }
   EC = std::error_code();
   return H;
@@ -156,14 +154,14 @@ file_t OpenFile(const path& Path, std::error_code& EC, CreationDisposition Disp,
       DWORD LastError = ::GetLastError();
       ::CloseHandle(Result);
       EC = wpi::mapWindowsError(LastError);
-      return kInvalidFile;
+      return WPI_kInvalidFile;
     }
   }
 
   if (Flags & OF_Delete) {
     if ((EC = setDeleteDisposition(Result, true))) {
       ::CloseHandle(Result);
-      return kInvalidFile;
+      return WPI_kInvalidFile;
     }
   }
   return Result;
@@ -174,7 +172,7 @@ file_t OpenFileForRead(const path& Path, std::error_code& EC, OpenFlags Flags) {
 }
 
 int FileToFd(file_t& F, std::error_code& EC, OpenFlags Flags) {
-  if (F == kInvalidFile) {
+  if (F == WPI_kInvalidFile) {
     EC = wpi::mapWindowsError(ERROR_INVALID_HANDLE);
     return -1;
   }
@@ -196,19 +194,17 @@ int FileToFd(file_t& F, std::error_code& EC, OpenFlags Flags) {
   }
 
   EC = std::error_code();
-  F = kInvalidFile;
+  F = WPI_kInvalidFile;
   return ResultFD;
 }
 
 void CloseFile(file_t& F) {
   ::CloseHandle(F);
-  F = kInvalidFile;
+  F = WPI_kInvalidFile;
 }
 
 #else  // _WIN32
 
-const file_t kInvalidFile = -1;
-
 static int nativeOpenFlags(CreationDisposition Disp, OpenFlags Flags,
                            FileAccess Access) {
   int Result = 0;
@@ -248,14 +244,14 @@ static int nativeOpenFlags(CreationDisposition Disp, OpenFlags Flags,
 file_t OpenFile(const path& Path, std::error_code& EC, CreationDisposition Disp,
                 FileAccess Access, OpenFlags Flags, unsigned Mode) {
   int OpenFlags = nativeOpenFlags(Disp, Flags, Access);
-  file_t ResultFD = kInvalidFile;
+  file_t ResultFD = WPI_kInvalidFile;
 
   // Call ::open in a lambda to avoid overload resolution in RetryAfterSignal
   // when open is overloaded, such as in Bionic.
   auto Open = [&]() { return ::open(Path.c_str(), OpenFlags, Mode); };
   if ((ResultFD = wpi::sys::RetryAfterSignal(-1, Open)) < 0) {
     EC = std::error_code(errno, std::generic_category());
-    return kInvalidFile;
+    return WPI_kInvalidFile;
   }
 #ifndef O_CLOEXEC
   if (!(Flags & OF_ChildInherit)) {
@@ -274,14 +270,14 @@ file_t OpenFileForRead(const path& Path, std::error_code& EC, OpenFlags Flags) {
 
 int FileToFd(file_t& F, std::error_code& EC, OpenFlags Flags) {
   int fd = F;
-  F = kInvalidFile;
+  F = WPI_kInvalidFile;
   EC = std::error_code();
   return fd;
 }
 
 void CloseFile(file_t& F) {
   ::close(F);
-  F = kInvalidFile;
+  F = WPI_kInvalidFile;
 }
 
 #endif  // _WIN32