[Support][CachePruning] Fix regression in pruning interval

[bd1976llvm]

Summary

borked by: rL284966 (see: https://reviews.llvm.org/D25730).

[labath]

Oops. I'm sorry about that.

[grimar]

I think this made few bots be unhappy:
http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/6726
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/3069

[andrewng]

In D40119#927529, @grimar wrote:

I think this made few bots be unhappy:
http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/6726
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/3069

Should be fixed by commit r318426. Sorry about the breakage.

llvm/trunk/lib/Support/CachePruning.cpp

if (auto EC = sys::fs::status(TimestampFile, FileStatus)) {
     if (EC == errc::no_such_file_or_directory) {
       // If the timestamp file wasn't there, create one now.
       writeTimestampFile(TimestampFile);
     } else {
       // Unknown error?
       return false;
     }
   } else {
-    if (Policy.Interval == seconds(0)) {
+    if (Policy.Interval != seconds(0)) {
       // Check whether the time stamp is older than our pruning interval.
       // If not, do nothing.
       const auto TimeStampModTime = FileStatus.getLastModificationTime();
       auto TimeStampAge = CurrentTime - TimeStampModTime;
       if (TimeStampAge <= Policy.Interval) {
         DEBUG(dbgs() << "Timestamp file too recent ("
                      << duration_cast<seconds>(TimeStampAge).count()
                      << "s old), do not prune.\n");