1 files changed, 47 insertions, 0 deletions
diff --git a/clang-tools-extra/clang-tidy/misc/UnusedRAII.h b/clang-tools-extra/clang-tidy/misc/UnusedRAII.h
new file mode 100644
index 00000000000..6850ab9a231
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/misc/UnusedRAII.h
@@ -0,0 +1,47 @@
+//===--- UnusedRAII.h - clang-tidy ------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_UNUSED_RAII_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_UNUSED_RAII_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+
+/// \brief Finds temporaries that look like RAII objects.
+///
+/// The canonical example for this is a scoped lock.
+/// \code
+///   {
+///     scoped_lock(&global_mutex);
+///     critical_section();
+///   }
+/// \endcode
+/// The destructor of the scoped_lock is called before the critical_section is
+/// entered, leaving it unprotected.
+///
+/// We apply a number of heuristics to reduce the false positive count of this
+/// check:
+///   - Ignore code expanded from macros. Testing frameworks make heavy use of
+///     this.
+///   - Ignore types with no user-declared constructor. Those are very unlikely
+///     to be RAII objects.
+///   - Ignore objects at the end of a compound statement (doesn't change behavior).
+///   - Ignore objects returned from a call.
+class UnusedRAIICheck : public ClangTidyCheck {
+public:
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_MISC_UNUSED_RAII_H