gecko-dev/mfbt/tests/TestNotNull.cpp
Michael Layzell 36e08437d0 Bug 1018486 - Part 8: Various other changes, r=smaug
MozReview-Commit-ID: B0dsomkWgEk
2016-09-07 10:50:45 -04:00

315 lines
10 KiB
C++

/* -*- 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 "mozilla/NotNull.h"
#include "mozilla/RefPtr.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/Unused.h"
using mozilla::WrapNotNull;
using mozilla::MakeUnique;
using mozilla::NotNull;
using mozilla::UniquePtr;
#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.
// At function's end all RefPtrs are destroyed and the refcount drops to 0
// and the MyRefType is destroyed.
}
int
main()
{
TestNotNullWithMyPtr();
TestNotNullWithRefPtr();
return 0;
}