[PATCH] D56806: [llvm-objcopy] Fix crash when writing empty binary output

[Jake Ehrlich via Phabricator via llvm-commits]

jakehehrlich added inline comments.


================
Comment at: llvm/tools/llvm-objcopy/Buffer.cpp:25-26
+  // disk.
+  if (sys::fs::exists(FileName))
+    if (std::error_code EC = sys::fs::remove(FileName))
+      return createFileError(FileName, errorCodeToError(EC));
----------------
Remove has a default parameter that sets weather or not it errors out if the file already exists. This removes a (well for this it doesn't actually matter in any case I've seen) race condition. To eliminate the condition entirely you need to create a temporary empty file on the same partition and then rename it into place. That behaves atomically. That's what FileBuffer is doing under the hood.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D56806/new/

https://reviews.llvm.org/D56806