unique_ptr-ify FileSystemStatCache::setNextStatCache

And in the process, discover that FileManager::removeStatCache had a
double-delete when removing an element from the middle of the list (at
the beginning or the end of the list, there was no problem) and add a
unit test to exercise the code path (which successfully crashed when run
(with modifications to match the old API) without this patch applied)

llvm-svn: 215388

1 files changed, 4 insertions, 2 deletions

diff --git a/clang/lib/Frontend/CacheTokens.cpp b/clang/lib/Frontend/CacheTokens.cpp
index 14f7027..23f22ad 100644
--- a/clang/lib/Frontend/CacheTokens.cpp
+++ b/clang/lib/Frontend/CacheTokens.cpp
@@ -572,8 +572,10 @@ void clang::CacheTokens(Preprocessor &PP, llvm::raw_fd_ostream* OS) {
   PTHWriter PW(*OS, PP);
 
   // Install the 'stat' system call listener in the FileManager.
-  StatListener *StatCache = new StatListener(PW.getPM());
-  PP.getFileManager().addStatCache(StatCache, /*AtBeginning=*/true);
+  auto StatCacheOwner = llvm::make_unique<StatListener>(PW.getPM());
+  StatListener *StatCache = StatCacheOwner.get();
+  PP.getFileManager().addStatCache(std::move(StatCacheOwner),
+                                   /*AtBeginning=*/true);
 
   // Lex through the entire file.  This will populate SourceManager with
   // all of the header information.