This fixes a regression introduced by r185726: the new call to get
a unique file does not prepend the system temporary directory, so
we need to anchor on the file that the temporary file gets moved
to to ensure we're on the same file system.
llvm-svn: 185825
This function is complementary to createTemporaryFile. It handles the case were
the unique file is *not* temporary: we will rename it in the end. Since we
will rename it, the file has to be in the same filesystem as the final
destination and we don't prepend the system temporary directory.
This has a small semantic difference from unique_file: the default mode is 0666.
This matches the behavior of most unix tools. For example, with this change
lld now produces files with the same permissions as ld. I will add a test
of this change when I port clang over to createUniqueFile (next commit).
llvm-svn: 185726
Manuel Klimek