Revert create_symbolic_link and both depending changes
This reverts commits r203136, r203137, and r203138.
This code doesn't build on Windows. Even on Vista+, Windows requires
elevated privileges to create a symlink. Therefore we can't use
symlinks in the compiler. We'll have to find another approach.
llvm-svn: 203143
diff --git a/llvm/lib/Support/LockFileManager.cpp b/llvm/lib/Support/LockFileManager.cpp
index 957f2fd..61afb79 100644
--- a/llvm/lib/Support/LockFileManager.cpp
+++ b/llvm/lib/Support/LockFileManager.cpp
@@ -115,42 +115,34 @@
}
}
- while (1) {
- // Create a symbolic link from the lock file name. If this succeeds, we're
- // done. Note that we are using symbolic link because hard links are not
- // supported by all filesystems.
- error_code EC
- = sys::fs::create_symbolic_link(UniqueLockFileName.str(),
- LockFileName.str());
- if (EC == errc::success)
- return;
+ // Create a hard link from the lock file name. If this succeeds, we're done.
+ error_code EC
+ = sys::fs::create_hard_link(UniqueLockFileName.str(),
+ LockFileName.str());
+ if (EC == errc::success)
+ return;
- if (EC != errc::file_exists) {
- Error = EC;
- return;
- }
+ // Creating the hard link failed.
- // Someone else managed to create the lock file first. Read the process ID
- // from the lock file.
- if ((Owner = readLockFile(LockFileName))) {
- // Wipe out our unique lock file (it's useless now)
- sys::fs::remove(UniqueLockFileName.str());
- return;
- }
+#ifdef LLVM_ON_UNIX
+ // The creation of the hard link may appear to fail, but if stat'ing the
+ // unique file returns a link count of 2, then we can still declare success.
+ struct stat StatBuf;
+ if (stat(UniqueLockFileName.c_str(), &StatBuf) == 0 &&
+ StatBuf.st_nlink == 2)
+ return;
+#endif
- if (!sys::fs::exists(LockFileName.str())) {
- // The previous owner released the lock file before we could read it.
- // Try to get ownership again.
- continue;
- }
+ // Someone else managed to create the lock file first. Wipe out our unique
+ // lock file (it's useless now) and read the process ID from the lock file.
+ sys::fs::remove(UniqueLockFileName.str());
+ if ((Owner = readLockFile(LockFileName)))
+ return;
- // There is a lock file that nobody owns; try to clean it up and get
- // ownership.
- if ((EC = sys::fs::remove(LockFileName.str()))) {
- Error = EC;
- return;
- }
- }
+ // There is a lock file that nobody owns; try to clean it up and report
+ // an error.
+ sys::fs::remove(LockFileName.str());
+ Error = EC;
}
LockFileManager::LockFileState LockFileManager::getState() const {