[clang-tidy] Treat references to smart pointers correctly in use-after-move.

Summary:
Previously, we weren't recognizing these as smart pointers and thus
weren't allowing non-dereference accesses as we should -- see new test
cases which fail without the fix.

Reviewers: alexfh, hokein, aaron.ballman, JonasToth

Reviewed By: JonasToth

Subscribers: xazax.hun, cfe-commits

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D56585

2 files changed, 14 insertions, 1 deletions

diff --git a/clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.cpp
index 11799ebf6d2..99c847ebc46 100644
--- a/clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/UseAfterMoveCheck.cpp
@@ -207,7 +207,7 @@ void UseAfterMoveFinder::getUsesAndReinits(
 }
 
 bool isStandardSmartPointer(const ValueDecl *VD) {
-  const Type *TheType = VD->getType().getTypePtrOrNull();
+  const Type *TheType = VD->getType().getNonReferenceType().getTypePtrOrNull();
   if (!TheType)
     return false;
 
diff --git a/clang-tools-extra/test/clang-tidy/bugprone-use-after-move.cpp b/clang-tools-extra/test/clang-tidy/bugprone-use-after-move.cpp
index 59dcb90cb49..dd37aec67b5 100644
--- a/clang-tools-extra/test/clang-tidy/bugprone-use-after-move.cpp
+++ b/clang-tools-extra/test/clang-tidy/bugprone-use-after-move.cpp
@@ -244,6 +244,19 @@ void standardSmartPtr() {
     std::move(ptr);
     ptr.get();
   }
+  // Make sure we treat references to smart pointers correctly.
+  {
+    std::unique_ptr<A> ptr;
+    std::unique_ptr<A>& ref_to_ptr = ptr;
+    std::move(ref_to_ptr);
+    ref_to_ptr.get();
+  }
+  {
+    std::unique_ptr<A> ptr;
+    std::unique_ptr<A>&& rvalue_ref_to_ptr = std::move(ptr);
+    std::move(rvalue_ref_to_ptr);
+    rvalue_ref_to_ptr.get();
+  }
   // We don't give any special treatment to types that are called "unique_ptr"
   // or "shared_ptr" but are not in the "::std" namespace.
   {