[libclang] Workaround potential race condition with code completion AllocatedResults being freed after a CXTranslationUnit.

The Container USR's CXString had its underlying data owned by the CXTranslationUnit's string pool.  This
would result in trying to access freed memory.

llvm-svn: 137887

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/tools/libclang/CXString.cpp b/clang/tools/libclang/CXString.cpp
index 268655ab8a5..bb09cd5cdc2 100644
--- a/clang/tools/libclang/CXString.cpp
+++ b/clang/tools/libclang/CXString.cpp
@@ -101,6 +101,10 @@ void cxstring::disposeCXStringBuf(CXStringBuf *buf) {
     static_cast<CXStringPool*>(buf->TU->StringPool)->push_back(buf);
 }
 
+bool cxstring::isManagedByPool(CXString str) {
+  return ((CXStringFlag) str.private_flags) == CXS_StringBuf;
+}
+
 //===----------------------------------------------------------------------===//
 // libClang public APIs.
 //===----------------------------------------------------------------------===//