[Support] Make sure sys::fs::remove can remove symbolic links and make sure LockFileManager can handle a symbolic link that points nowhere.

llvm-svn: 204422

1 files changed, 3 insertions, 6 deletions

diff --git a/llvm/lib/Support/LockFileManager.cpp b/llvm/lib/Support/LockFileManager.cpp
index ba1047b88ac..c8472d88055 100644
--- a/llvm/lib/Support/LockFileManager.cpp
+++ b/llvm/lib/Support/LockFileManager.cpp
@@ -29,16 +29,13 @@ using namespace llvm;
 /// \returns The process ID of the process that owns this lock file
 Optional<std::pair<std::string, int> >
 LockFileManager::readLockFile(StringRef LockFileName) {
-  // Check whether the lock file exists. If not, clearly there's nothing
-  // to read, so we just return.
-  if (!sys::fs::exists(LockFileName))
-    return None;
-
   // Read the owning host and PID out of the lock file. If it appears that the
   // owning process is dead, the lock file is invalid.
   std::unique_ptr<MemoryBuffer> MB;
-  if (MemoryBuffer::getFile(LockFileName, MB))
+  if (MemoryBuffer::getFile(LockFileName, MB)) {
+    sys::fs::remove(LockFileName);
     return None;
+  }
 
   StringRef Hostname;
   StringRef PIDStr;