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-rw-r--r--mfbt/tests/TestNotNull.cpp386
1 files changed, 386 insertions, 0 deletions
diff --git a/mfbt/tests/TestNotNull.cpp b/mfbt/tests/TestNotNull.cpp
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+++ b/mfbt/tests/TestNotNull.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <type_traits>
+
+#include "mozilla/NotNull.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/Unused.h"
+
+using mozilla::MakeNotNull;
+using mozilla::NotNull;
+using mozilla::UniquePtr;
+using mozilla::WrapNotNull;
+
+#define CHECK MOZ_RELEASE_ASSERT
+
+class Blah {
+ public:
+ Blah() : mX(0) {}
+ void blah(){};
+ int mX;
+};
+
+// A simple smart pointer that implicity converts to and from T*.
+template <typename T>
+class MyPtr {
+ T* mRawPtr;
+
+ public:
+ MyPtr() : mRawPtr(nullptr) {}
+ MOZ_IMPLICIT MyPtr(T* aRawPtr) : mRawPtr(aRawPtr) {}
+
+ T* get() const { return mRawPtr; }
+ operator T*() const { return get(); }
+
+ T* operator->() const { return get(); }
+};
+
+// A simple class that works with RefPtr. It keeps track of the maximum
+// refcount value for testing purposes.
+class MyRefType {
+ int mExpectedMaxRefCnt;
+ int mMaxRefCnt;
+ int mRefCnt;
+
+ public:
+ explicit MyRefType(int aExpectedMaxRefCnt)
+ : mExpectedMaxRefCnt(aExpectedMaxRefCnt), mMaxRefCnt(0), mRefCnt(0) {}
+
+ ~MyRefType() { CHECK(mMaxRefCnt == mExpectedMaxRefCnt); }
+
+ uint32_t AddRef() {
+ mRefCnt++;
+ if (mRefCnt > mMaxRefCnt) {
+ mMaxRefCnt = mRefCnt;
+ }
+ return mRefCnt;
+ }
+
+ uint32_t Release() {
+ CHECK(mRefCnt > 0);
+ mRefCnt--;
+ if (mRefCnt == 0) {
+ delete this;
+ return 0;
+ }
+ return mRefCnt;
+ }
+};
+
+void f_i(int* aPtr) {}
+void f_my(MyPtr<int> aPtr) {}
+
+void f_nni(NotNull<int*> aPtr) {}
+void f_nnmy(NotNull<MyPtr<int>> aPtr) {}
+
+void TestNotNullWithMyPtr() {
+ int i4 = 4;
+ int i5 = 5;
+
+ MyPtr<int> my4 = &i4;
+ MyPtr<int> my5 = &i5;
+
+ NotNull<int*> nni4 = WrapNotNull(&i4);
+ NotNull<int*> nni5 = WrapNotNull(&i5);
+ NotNull<MyPtr<int>> nnmy4 = WrapNotNull(my4);
+
+ // WrapNotNull(nullptr); // no wrapping from nullptr
+ // WrapNotNull(0); // no wrapping from zero
+
+ // NotNull<int*> construction combinations
+ // NotNull<int*> nni4a; // no default
+ // NotNull<int*> nni4a(nullptr); // no nullptr
+ // NotNull<int*> nni4a(0); // no zero
+ // NotNull<int*> nni4a(&i4); // no int*
+ // NotNull<int*> nni4a(my4); // no MyPtr<int>
+ NotNull<int*> nni4b(WrapNotNull(&i4)); // WrapNotNull(int*)
+ NotNull<int*> nni4c(WrapNotNull(my4)); // WrapNotNull(MyPtr<int>)
+ NotNull<int*> nni4d(nni4); // NotNull<int*>
+ NotNull<int*> nni4e(nnmy4); // NotNull<MyPtr<int>>
+ CHECK(*nni4b == 4);
+ CHECK(*nni4c == 4);
+ CHECK(*nni4d == 4);
+ CHECK(*nni4e == 4);
+
+ // NotNull<MyPtr<int>> construction combinations
+ // NotNull<MyPtr<int>> nnmy4a; // no default
+ // NotNull<MyPtr<int>> nnmy4a(nullptr); // no nullptr
+ // NotNull<MyPtr<int>> nnmy4a(0); // no zero
+ // NotNull<MyPtr<int>> nnmy4a(&i4); // no int*
+ // NotNull<MyPtr<int>> nnmy4a(my4); // no MyPtr<int>
+ NotNull<MyPtr<int>> nnmy4b(WrapNotNull(&i4)); // WrapNotNull(int*)
+ NotNull<MyPtr<int>> nnmy4c(WrapNotNull(my4)); // WrapNotNull(MyPtr<int>)
+ NotNull<MyPtr<int>> nnmy4d(nni4); // NotNull<int*>
+ NotNull<MyPtr<int>> nnmy4e(nnmy4); // NotNull<MyPtr<int>>
+ CHECK(*nnmy4b == 4);
+ CHECK(*nnmy4c == 4);
+ CHECK(*nnmy4d == 4);
+ CHECK(*nnmy4e == 4);
+
+ // NotNull<int*> assignment combinations
+ // nni4b = nullptr; // no nullptr
+ // nni4b = 0; // no zero
+ // nni4a = &i4; // no int*
+ // nni4a = my4; // no MyPtr<int>
+ nni4b = WrapNotNull(&i4); // WrapNotNull(int*)
+ nni4c = WrapNotNull(my4); // WrapNotNull(MyPtr<int>)
+ nni4d = nni4; // NotNull<int*>
+ nni4e = nnmy4; // NotNull<MyPtr<int>>
+ CHECK(*nni4b == 4);
+ CHECK(*nni4c == 4);
+ CHECK(*nni4d == 4);
+ CHECK(*nni4e == 4);
+
+ // NotNull<MyPtr<int>> assignment combinations
+ // nnmy4a = nullptr; // no nullptr
+ // nnmy4a = 0; // no zero
+ // nnmy4a = &i4; // no int*
+ // nnmy4a = my4; // no MyPtr<int>
+ nnmy4b = WrapNotNull(&i4); // WrapNotNull(int*)
+ nnmy4c = WrapNotNull(my4); // WrapNotNull(MyPtr<int>)
+ nnmy4d = nni4; // NotNull<int*>
+ nnmy4e = nnmy4; // NotNull<MyPtr<int>>
+ CHECK(*nnmy4b == 4);
+ CHECK(*nnmy4c == 4);
+ CHECK(*nnmy4d == 4);
+ CHECK(*nnmy4e == 4);
+
+ NotNull<MyPtr<int>> nnmy5 = WrapNotNull(&i5);
+ CHECK(*nnmy5 == 5);
+ CHECK(nnmy5 == &i5); // NotNull<MyPtr<int>> == int*
+ CHECK(nnmy5 == my5); // NotNull<MyPtr<int>> == MyPtr<int>
+ CHECK(nnmy5 == nni5); // NotNull<MyPtr<int>> == NotNull<int*>
+ CHECK(nnmy5 == nnmy5); // NotNull<MyPtr<int>> == NotNull<MyPtr<int>>
+ CHECK(&i5 == nnmy5); // int* == NotNull<MyPtr<int>>
+ CHECK(my5 == nnmy5); // MyPtr<int> == NotNull<MyPtr<int>>
+ CHECK(nni5 == nnmy5); // NotNull<int*> == NotNull<MyPtr<int>>
+ CHECK(nnmy5 == nnmy5); // NotNull<MyPtr<int>> == NotNull<MyPtr<int>>
+ // CHECK(nni5 == nullptr); // no comparisons with nullptr
+ // CHECK(nullptr == nni5); // no comparisons with nullptr
+ // CHECK(nni5 == 0); // no comparisons with zero
+ // CHECK(0 == nni5); // no comparisons with zero
+
+ CHECK(*nnmy5 == 5);
+ CHECK(nnmy5 != &i4); // NotNull<MyPtr<int>> != int*
+ CHECK(nnmy5 != my4); // NotNull<MyPtr<int>> != MyPtr<int>
+ CHECK(nnmy5 != nni4); // NotNull<MyPtr<int>> != NotNull<int*>
+ CHECK(nnmy5 != nnmy4); // NotNull<MyPtr<int>> != NotNull<MyPtr<int>>
+ CHECK(&i4 != nnmy5); // int* != NotNull<MyPtr<int>>
+ CHECK(my4 != nnmy5); // MyPtr<int> != NotNull<MyPtr<int>>
+ CHECK(nni4 != nnmy5); // NotNull<int*> != NotNull<MyPtr<int>>
+ CHECK(nnmy4 != nnmy5); // NotNull<MyPtr<int>> != NotNull<MyPtr<int>>
+ // CHECK(nni4 != nullptr); // no comparisons with nullptr
+ // CHECK(nullptr != nni4); // no comparisons with nullptr
+ // CHECK(nni4 != 0); // no comparisons with zero
+ // CHECK(0 != nni4); // no comparisons with zero
+
+ // int* parameter
+ f_i(&i4); // identity int* --> int*
+ f_i(my4); // implicit MyPtr<int> --> int*
+ f_i(my4.get()); // explicit MyPtr<int> --> int*
+ f_i(nni4); // implicit NotNull<int*> --> int*
+ f_i(nni4.get()); // explicit NotNull<int*> --> int*
+ // f_i(nnmy4); // no implicit NotNull<MyPtr<int>> --> int*
+ f_i(nnmy4.get()); // explicit NotNull<MyPtr<int>> --> int*
+ f_i(nnmy4.get().get()); // doubly-explicit NotNull<MyPtr<int>> --> int*
+
+ // MyPtr<int> parameter
+ f_my(&i4); // implicit int* --> MyPtr<int>
+ f_my(my4); // identity MyPtr<int> --> MyPtr<int>
+ f_my(my4.get()); // explicit MyPtr<int> --> MyPtr<int>
+ // f_my(nni4); // no implicit NotNull<int*> --> MyPtr<int>
+ f_my(nni4.get()); // explicit NotNull<int*> --> MyPtr<int>
+ f_my(nnmy4); // implicit NotNull<MyPtr<int>> --> MyPtr<int>
+ f_my(nnmy4.get()); // explicit NotNull<MyPtr<int>> --> MyPtr<int>
+ f_my(
+ nnmy4.get().get()); // doubly-explicit NotNull<MyPtr<int>> --> MyPtr<int>
+
+ // NotNull<int*> parameter
+ f_nni(nni4); // identity NotNull<int*> --> NotNull<int*>
+ f_nni(nnmy4); // implicit NotNull<MyPtr<int>> --> NotNull<int*>
+
+ // NotNull<MyPtr<int>> parameter
+ f_nnmy(nni4); // implicit NotNull<int*> --> NotNull<MyPtr<int>>
+ f_nnmy(nnmy4); // identity NotNull<MyPtr<int>> --> NotNull<MyPtr<int>>
+
+ // CHECK(nni4); // disallow boolean conversion / unary expression usage
+ // CHECK(nnmy4); // ditto
+
+ // '->' dereferencing.
+ Blah blah;
+ MyPtr<Blah> myblah = &blah;
+ NotNull<Blah*> nnblah = WrapNotNull(&blah);
+ NotNull<MyPtr<Blah>> nnmyblah = WrapNotNull(myblah);
+ (&blah)->blah(); // int*
+ myblah->blah(); // MyPtr<int>
+ nnblah->blah(); // NotNull<int*>
+ nnmyblah->blah(); // NotNull<MyPtr<int>>
+
+ (&blah)->mX = 1;
+ CHECK((&blah)->mX == 1);
+ myblah->mX = 2;
+ CHECK(myblah->mX == 2);
+ nnblah->mX = 3;
+ CHECK(nnblah->mX == 3);
+ nnmyblah->mX = 4;
+ CHECK(nnmyblah->mX == 4);
+
+ // '*' dereferencing (lvalues and rvalues)
+ *(&i4) = 7; // int*
+ CHECK(*(&i4) == 7);
+ *my4 = 6; // MyPtr<int>
+ CHECK(*my4 == 6);
+ *nni4 = 5; // NotNull<int*>
+ CHECK(*nni4 == 5);
+ *nnmy4 = 4; // NotNull<MyPtr<int>>
+ CHECK(*nnmy4 == 4);
+
+ // Non-null arrays.
+ static const int N = 20;
+ int a[N];
+ NotNull<int*> nna = WrapNotNull(a);
+ for (int i = 0; i < N; i++) {
+ nna[i] = i;
+ }
+ for (int i = 0; i < N; i++) {
+ nna[i] *= 2;
+ }
+ for (int i = 0; i < N; i++) {
+ CHECK(nna[i] == i * 2);
+ }
+}
+
+void f_ref(NotNull<MyRefType*> aR) { NotNull<RefPtr<MyRefType>> r = aR; }
+
+void TestNotNullWithRefPtr() {
+ // This MyRefType object will have a maximum refcount of 5.
+ NotNull<RefPtr<MyRefType>> r1 = WrapNotNull(new MyRefType(5));
+
+ // At this point the refcount is 1.
+
+ NotNull<RefPtr<MyRefType>> r2 = r1;
+
+ // At this point the refcount is 2.
+
+ NotNull<MyRefType*> r3 = r2;
+ (void)r3;
+
+ // At this point the refcount is still 2.
+
+ RefPtr<MyRefType> r4 = r2;
+ mozilla::Unused << r4;
+
+ // At this point the refcount is 3.
+
+ RefPtr<MyRefType> r5 = r3.get();
+ mozilla::Unused << r5;
+
+ // At this point the refcount is 4.
+
+ // No change to the refcount occurs because of the argument passing. Within
+ // f_ref() the refcount temporarily hits 5, due to the local RefPtr.
+ f_ref(r2);
+
+ // At this point the refcount is 4.
+
+ NotNull<RefPtr<MyRefType>> r6 = std::move(r2);
+ mozilla::Unused << r6;
+
+ CHECK(r2.get());
+ CHECK(r6.get());
+
+ // At this point the refcount is 5 again, since NotNull is not movable.
+
+ // At function's end all RefPtrs are destroyed and the refcount drops to 0
+ // and the MyRefType is destroyed.
+}
+
+// Create a derived object and store its base pointer.
+struct Base {
+ virtual ~Base() = default;
+ virtual bool IsDerived() const { return false; }
+};
+struct Derived : Base {
+ bool IsDerived() const override { return true; }
+};
+
+void TestMakeNotNull() {
+ // Raw pointer.
+ auto nni = MakeNotNull<int*>(11);
+ static_assert(std::is_same_v<NotNull<int*>, decltype(nni)>,
+ "MakeNotNull<int*> should return NotNull<int*>");
+ CHECK(*nni == 11);
+ delete nni;
+
+ // Raw pointer to const.
+ auto nnci = MakeNotNull<const int*>(12);
+ static_assert(std::is_same_v<NotNull<const int*>, decltype(nnci)>,
+ "MakeNotNull<const int*> should return NotNull<const int*>");
+ CHECK(*nnci == 12);
+ delete nnci;
+
+ auto nnd = MakeNotNull<Derived*>();
+ static_assert(std::is_same_v<NotNull<Derived*>, decltype(nnd)>,
+ "MakeNotNull<Derived*> should return NotNull<Derived*>");
+ CHECK(nnd->IsDerived());
+ delete nnd;
+ NotNull<Base*> nnb = MakeNotNull<Derived*>();
+ static_assert(std::is_same_v<NotNull<Base*>, decltype(nnb)>,
+ "MakeNotNull<Derived*> should be assignable to NotNull<Base*>");
+ // Check that we have really built a Derived object.
+ CHECK(nnb->IsDerived());
+ delete nnb;
+
+ // Allow smart pointers.
+ auto nnmi = MakeNotNull<MyPtr<int>>(23);
+ static_assert(std::is_same_v<NotNull<MyPtr<int>>, decltype(nnmi)>,
+ "MakeNotNull<MyPtr<int>> should return NotNull<MyPtr<int>>");
+ CHECK(*nnmi == 23);
+ delete nnmi.get().get();
+
+ auto nnui = MakeNotNull<UniquePtr<int>>(24);
+ static_assert(
+ std::is_same_v<NotNull<UniquePtr<int>>, decltype(nnui)>,
+ "MakeNotNull<UniquePtr<int>> should return NotNull<UniquePtr<int>>");
+ CHECK(*nnui == 24);
+
+ // Expect only 1 RefCnt (from construction).
+ auto nnr = MakeNotNull<RefPtr<MyRefType>>(1);
+ static_assert(std::is_same_v<NotNull<RefPtr<MyRefType>>, decltype(nnr)>,
+ "MakeNotNull<RefPtr<MyRefType>> should return "
+ "NotNull<RefPtr<MyRefType>>");
+ mozilla::Unused << nnr;
+}
+
+mozilla::MovingNotNull<UniquePtr<int>> CreateNotNullUniquePtr() {
+ return mozilla::WrapMovingNotNull(mozilla::MakeUnique<int>(42));
+}
+
+void TestMovingNotNull() {
+ UniquePtr<int> x1 = CreateNotNullUniquePtr();
+ CHECK(x1);
+ CHECK(42 == *x1);
+
+ NotNull<UniquePtr<int>> x2 = CreateNotNullUniquePtr();
+ CHECK(42 == *x2);
+
+ NotNull<UniquePtr<Base>> x3 =
+ mozilla::WrapMovingNotNull(mozilla::MakeUnique<Derived>());
+
+ // Must not compile:
+ // auto y = CreateNotNullUniquePtr();
+}
+
+int main() {
+ TestNotNullWithMyPtr();
+ TestNotNullWithRefPtr();
+ TestMakeNotNull();
+ TestMovingNotNull();
+
+ return 0;
+}
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