1 files changed, 52 insertions, 0 deletions
diff --git a/clang/lib/StaticAnalyzer/Checkers/TrustNonnullChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/TrustNonnullChecker.cpp
new file mode 100644
index 00000000000..3b299441d1e
--- /dev/null
+++ b/clang/lib/StaticAnalyzer/Checkers/TrustNonnullChecker.cpp
@@ -0,0 +1,52 @@
+//== TrustNonnullChecker.cpp - Checker for trusting annotations -*- C++ -*--==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This checker adds an assumption that methods annotated with _Nonnull
+// which come from system headers actually return a non-null pointer.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangSACheckers.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+
+using namespace clang;
+using namespace ento;
+
+namespace {
+
+class TrustNonnullChecker : public Checker<check::PostCall> {
+public:
+  void checkPostCall(const CallEvent &Call, CheckerContext &C) const {
+    // Only trust annotations for system headers for non-protocols.
+    if (!Call.isInSystemHeader())
+      return;
+
+    QualType RetType = Call.getResultType();
+    if (!RetType->isAnyPointerType())
+      return;
+
+    ProgramStateRef State = C.getState();
+    if (getNullabilityAnnotation(RetType) == Nullability::Nonnull)
+      if (auto L = Call.getReturnValue().getAs<Loc>())
+        State = State->assume(*L, /*Assumption=*/true);
+
+    C.addTransition(State);
+  }
+};
+
+} // end empty namespace
+
+
+void ento::registerTrustNonnullChecker(CheckerManager &Mgr) {
+  Mgr.registerChecker<TrustNonnullChecker>();
+}