[raw_fd_ostream] report actual error in error messages

Summary:
Previously, we would emit error messages like "IO failure on output
stream". This change causes use to include information about what
actually went wrong, e.g. "No space left on device".

Reviewers: sunfish, rnk

Reviewed By: rnk

Subscribers: mehdi_amini, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D39203

llvm-svn: 316404

1 files changed, 2 insertions, 3 deletions

diff --git a/llvm/lib/Support/LockFileManager.cpp b/llvm/lib/Support/LockFileManager.cpp
index 3ee3af7..81f3fd0 100644
--- a/llvm/lib/Support/LockFileManager.cpp
+++ b/llvm/lib/Support/LockFileManager.cpp
@@ -201,12 +201,11 @@ LockFileManager::LockFileManager(StringRef FileName)
     Out.close();
 
     if (Out.has_error()) {
-      // We failed to write out PID, so make up an excuse, remove the
+      // We failed to write out PID, so report the error, remove the
       // unique lock file, and fail.
-      auto EC = make_error_code(errc::no_space_on_device);
       std::string S("failed to write to ");
       S.append(UniqueLockFileName.str());
-      setError(EC, S);
+      setError(Out.error(), S);
       sys::fs::remove(UniqueLockFileName);
       return;
     }