Avoid the deprecated GetVersionEx API

Apparently the preferred version is the incredibly complicated
VerifyVersionInfoW function.

Rename the function to avoid potential future name clashes.

llvm-svn: 257415

2 files changed, 19 insertions, 10 deletions

diff --git a/llvm/lib/Support/Windows/WindowsSupport.h b/llvm/lib/Support/Windows/WindowsSupport.h
index cb091f18640..60490f26643 100644
--- a/llvm/lib/Support/Windows/WindowsSupport.h
+++ b/llvm/lib/Support/Windows/WindowsSupport.h
@@ -48,16 +48,25 @@
 #include <vector>
 
 /// Determines if the program is running on Windows 8 or newer. This
-/// reimplements the helpers in the Windows 8.1 SDK, which are intended to
-/// supercede raw calls to GetVersionEx, because old Windows SDKs, Cygwin, and
-/// MinGW don't have VersionSupport.h yet.
-inline bool IsWindows8OrGreater() {
-  OSVERSIONINFO osvi = {};
+/// reimplements one of the helpers in the Windows 8.1 SDK, which are intended
+/// to supercede raw calls to GetVersionEx. Old SDKs, Cygwin, and MinGW don't
+/// yet have VersionHelpers.h, so we have our own helper.
+inline bool RunningWindows8OrGreater() {
+  // Windows 8 is version 6.2, service pack 0.
+  OSVERSIONINFOEXW osvi = {};
   osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
-  if (!::GetVersionEx(&osvi))
-    return false;
-  return (osvi.dwMajorVersion > 6 ||
-          (osvi.dwMajorVersion == 6 && osvi.dwMinorVersion >= 2));
+  osvi.dwMajorVersion = 6;
+  osvi.dwMinorVersion = 2;
+  osvi.wServicePackMajor = 0;
+
+  DWORDLONG Mask = 0;
+  Mask = VerSetConditionMask(Mask, VER_MAJORVERSION, VER_GREATER_EQUAL);
+  Mask = VerSetConditionMask(Mask, VER_MINORVERSION, VER_GREATER_EQUAL);
+  Mask = VerSetConditionMask(Mask, VER_SERVICEPACKMAJOR, VER_GREATER_EQUAL);
+
+  return VerifyVersionInfoW(&osvi, VER_MAJORVERSION | VER_MINORVERSION |
+                                       VER_SERVICEPACKMAJOR,
+                            Mask) != FALSE;
 }
 
 inline bool MakeErrMsg(std::string* ErrMsg, const std::string& prefix) {
diff --git a/llvm/lib/Support/raw_ostream.cpp b/llvm/lib/Support/raw_ostream.cpp
index 57162dc6e95..15813fd3e66 100644
--- a/llvm/lib/Support/raw_ostream.cpp
+++ b/llvm/lib/Support/raw_ostream.cpp
@@ -577,7 +577,7 @@ void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
   // 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) && !IsWindows8OrGreater();
+  bool ShouldWriteInChunks = !!::_isatty(FD) && !RunningWindows8OrGreater();
 #endif
 
   do {