assert(FD >= 0 && "File already closed.");
pos += Size;
-#ifndef LLVM_ON_WIN32
+ // The maximum write size is limited to SSIZE_MAX because a write
+ // greater than SSIZE_MAX is implementation-defined in POSIX.
+ // Since SSIZE_MAX is not portable, we use SIZE_MAX >> 1 instead.
+ size_t MaxWriteSize = SIZE_MAX >> 1;
+
#if defined(__linux__)
- bool ShouldWriteInChunks = true;
-#else
- bool ShouldWriteInChunks = false;
-#endif
-#else
+ // It is observed that Linux returns EINVAL for a very large write (>2G).
+ // Make it a reasonably small value.
+ MaxWriteSize = 1024 * 1024 * 1024;
+#elif defined(LLVM_ON_WIN32)
// Writing a large size of output to Windows console returns ENOMEM. It seems
// that, prior to Windows 8, WriteFile() is redirecting to WriteConsole(), and
// the latter has a size limit (66000 bytes or less, depending on heap usage).
- bool ShouldWriteInChunks = !!::_isatty(FD) && !RunningWindows8OrGreater();
+ if (::_isatty(FD) && !RunningWindows8OrGreater())
+ MaxWriteSize = 32767;
#endif
do {
- size_t ChunkSize = Size;
- if (ChunkSize > 32767 && ShouldWriteInChunks)
- ChunkSize = 32767;
-
+ size_t ChunkSize = std::min(Size, MaxWriteSize);
ssize_t ret = ::write(FD, Ptr, ChunkSize);
if (ret < 0) {