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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,
#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;
}