1 files changed, 76 insertions, 0 deletions
diff --git a/build/clang-plugin/tests/TestRefCountedThisInsideConstructor.cpp b/build/clang-plugin/tests/TestRefCountedThisInsideConstructor.cpp
new file mode 100644
index 0000000000..a6684e3812
--- /dev/null
+++ b/build/clang-plugin/tests/TestRefCountedThisInsideConstructor.cpp
@@ -0,0 +1,76 @@
+#include <functional>
+
+#include <mozilla/RefPtr.h>
+
+struct RefCountedBase {
+  void AddRef();
+  void Release();
+};
+
+struct Bar;
+
+struct Foo : RefCountedBase {
+  void foo();
+};
+
+struct Bar : RefCountedBase {
+  Bar() {
+    RefPtr<Bar> self = this; // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+    auto self2 = RefPtr(this); // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+    auto self3 = RefPtr{this}; // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+    RefPtr<Bar> self4(this); // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+    RefPtr<Bar> self5{this}; // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+    [self=RefPtr{this}]{}(); // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+    refptr(RefPtr{this}); // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+    refptr(this); // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+  }
+
+  explicit Bar(float f) {
+    // Does not match member expressions with `this`
+    RefPtr<Foo> foo = this->mFoo;
+    foo->foo();
+    auto foo2 = RefPtr(this->mFoo);
+    foo2->foo();
+    auto foo3 = RefPtr{this->mFoo};
+    foo3->foo();
+  }
+
+  explicit Bar(short i);
+
+  explicit Bar(int i): mBar(this) {} // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+  explicit Bar(int i, int i2): mBar(RefPtr(this)) {} // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+
+  void Init() {
+    // Does not match outside the constructor
+    RefPtr<Bar> self = this;
+    auto self2 = RefPtr(this);
+    auto self3 = RefPtr{this};
+  }
+
+  void refptr(const RefPtr<Bar>& aBar) {}
+
+  RefPtr<Foo> mFoo;
+  RefPtr<Bar> mBar;
+};
+
+// Test case for non-inline constructor
+Bar::Bar(short i) {
+  RefPtr<Bar> self = this; // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+  auto self2 = RefPtr(this); // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+  auto self3 = RefPtr{this}; // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+}
+
+// Same goes for any class with MOZ_IS_REFPTR (not including nsCOMPtr because SM
+// doesn't have it)
+template <typename T> class MOZ_IS_REFPTR MyRefPtr {
+public:
+  MOZ_IMPLICIT MyRefPtr(T *aPtr) : mPtr(aPtr) {}
+  T *mPtr;
+};
+
+class Baz : RefCountedBase {
+  Baz() {
+    MyRefPtr<Baz> self = this; // expected-error {{Refcounting `this` inside the constructor is a footgun, `this` may be destructed at the end of the constructor unless there's another strong reference. Consider adding a separate Create function and do the work there.}}
+    (void)self;
+  }
+};