Bazel client, Windows: use CreateFileW

Use CreateFileW in blaze_util_windows.cc when
opening the "jvm.out" file. This allows supporting
long paths.

Also use AsWindowsPathWithUncPrefix instead of
just AsWindowsPath plus manually adding the UNC
prefix.

Also fix a compilation error in
file_windows_test.cc, I'm surprised the CI system
didn't catch this, maybe we aren't running this
test there.

See https://github.com/bazelbuild/bazel/issues/2107
See https://github.com/bazelbuild/bazel/issues/2181

--
PiperOrigin-RevId: 144813245
MOS_MIGRATED_REVID=144813245

1 files changed, 16 insertions, 4 deletions

diff --git a/src/main/cpp/util/file_windows.cc b/src/main/cpp/util/file_windows.cc
index 5848e48d16..de3bd2800e 100644
--- a/src/main/cpp/util/file_windows.cc
+++ b/src/main/cpp/util/file_windows.cc
@@ -52,9 +52,6 @@ static bool IsDirectoryW(const wstring& path);
 // necessary.
 static bool UnlinkPathW(const wstring& path);
 
-// Like `AsWindowsPath` but the result is absolute and has UNC prefix if needed.
-static bool AsWindowsPathWithUncPrefix(const string& path, wstring* wpath);
-
 static bool IsRootDirectoryW(const wstring& path);
 
 static bool MakeDirectoriesW(const wstring& path);
@@ -293,6 +290,21 @@ void MsysRoot::InitIfNecessary() {
   }
 }
 
+// Converts a UTF8-encoded `path` to a normalized, widechar Windows path.
+//
+// Returns true if conversion succeeded and sets the contents of `result` to it.
+//
+// The `path` may be absolute or relative, and may be a Windows or MSYS path.
+// In every case, the output is normalized (see NormalizeWindowsPath).
+// The output won't have a UNC prefix, even if `path` did.
+//
+// Recognizes the drive letter in MSYS paths, so e.g. "/c/windows" becomes
+// "c:\windows". Prepends the MSYS root (computed from the BAZEL_SH envvar) to
+// absolute MSYS paths, so e.g. "/usr" becomes "c:\tools\msys64\usr".
+//
+// The result may be longer than MAX_PATH. It's the caller's responsibility to
+// prepend the UNC prefix in case they need to pass it to a WinAPI function
+// (some require the prefix, some don't), or to quote the path if necessary.
 bool AsWindowsPath(const string& path, wstring* result) {
   if (path.empty()) {
     result->clear();
@@ -332,7 +344,7 @@ bool AsWindowsPath(const string& path, wstring* result) {
   return true;
 }
 
-static bool AsWindowsPathWithUncPrefix(const string& path, wstring* wpath) {
+bool AsWindowsPathWithUncPrefix(const string& path, wstring* wpath) {
   if (IsDevNull(path)) {
     wpath->assign(L"NUL");
     return true;