Files
abseil-cpp/absl/base/internal/nullability_traits_test.cc
Abseil Team f138b9d6fa Annotate ABSL_DIE_IF_NULL's return type with absl_nonnull
This helps inform Nullability inference without needing any special casing.

Since ABSL_DIE_IF_NULL is allowed for pointers, smart pointers, or classes marked with ABSL_NULLABILITY_COMPATIBLE we introduce a trait to help add the annotation only when compatible. This trait is kept internal for now out of caution for what we are supporting, though people have asked about it before (see b/394789178).

Simple cases are tested by `-Wnonnull` in absl/base/nullability_nc_test.cc. However, it's unclear how to test the complex cases like templates with universal references with the simple compiler `-Wnonnull`. There is a followup nullability inference test (cl/808830606).

Since there is Wnullability-completeness, needed to annotate the rest of die_if_null.h

PiperOrigin-RevId: 810463021
Change-Id: Id5156996bf3a29a99e689974ac2af7b94b21c460
2025-09-23 09:09:36 -07:00

99 lines
3.5 KiB
C++

// Copyright 2025 The Abseil Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/base/internal/nullability_traits.h"
#include <memory>
#include <type_traits>
#include "gtest/gtest.h"
#include "absl/base/config.h"
#include "absl/base/nullability.h"
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace base_internal {
namespace {
struct NotSmartPtr {
int* x;
};
class ABSL_NULLABILITY_COMPATIBLE MySmartPtr : std::unique_ptr<int> {};
// The IsNullabilityCompatibleType trait value can only be true when we define
// `absl_nullable` (isn't a no-op).
#if defined(__clang__) && !defined(__OBJC__) && \
ABSL_HAVE_FEATURE(nullability_on_classes)
#define EXPECT_TRUE_IF_SUPPORTED EXPECT_TRUE
#else
#define EXPECT_TRUE_IF_SUPPORTED EXPECT_FALSE
#endif
TEST(NullabilityTraitsTest, IsNullabilityEligibleTypePrimitives) {
EXPECT_FALSE(IsNullabilityCompatibleType<int>::value);
EXPECT_FALSE(IsNullabilityCompatibleType<int*&>::value);
EXPECT_TRUE_IF_SUPPORTED(IsNullabilityCompatibleType<int*>::value);
EXPECT_TRUE_IF_SUPPORTED(IsNullabilityCompatibleType<int**>::value);
EXPECT_TRUE_IF_SUPPORTED(IsNullabilityCompatibleType<int* const>::value);
EXPECT_TRUE_IF_SUPPORTED(IsNullabilityCompatibleType<const int*>::value);
EXPECT_TRUE_IF_SUPPORTED(IsNullabilityCompatibleType<void (*)(int)>::value);
}
TEST(NullabilityTraitsTest, IsNullabilityCompatibleTypeAliases) {
using MyInt = int;
using MyIntPtr = int*;
EXPECT_FALSE(IsNullabilityCompatibleType<MyInt>::value);
EXPECT_TRUE_IF_SUPPORTED(IsNullabilityCompatibleType<MyIntPtr>::value);
}
TEST(NullabilityTraitsTest, IsNullabilityCompatibleTypeSmartPointers) {
EXPECT_TRUE_IF_SUPPORTED(
IsNullabilityCompatibleType<std::unique_ptr<int>>::value);
EXPECT_TRUE_IF_SUPPORTED(
IsNullabilityCompatibleType<std::shared_ptr<int>>::value);
EXPECT_FALSE(IsNullabilityCompatibleType<NotSmartPtr>::value);
EXPECT_TRUE_IF_SUPPORTED(IsNullabilityCompatibleType<NotSmartPtr*>::value);
EXPECT_TRUE_IF_SUPPORTED(IsNullabilityCompatibleType<MySmartPtr>::value);
}
#undef EXPECT_TRUE_IF_SUPPORTED
TEST(NullabilityTraitsTest, AddNonnullIfCompatiblePassThroughPrimitives) {
EXPECT_TRUE((std::is_same_v<AddNonnullIfCompatible<int>::type, int>));
EXPECT_TRUE((std::is_same_v<AddNonnullIfCompatible<int*>::type, int*>));
EXPECT_TRUE(
(std::is_same_v<AddNonnullIfCompatible<int* const>::type, int* const>));
}
TEST(NullabilityTraitsTest, AddNonnullIfCompatiblePassThroughSmartPointers) {
EXPECT_TRUE(
(std::is_same_v<AddNonnullIfCompatible<std::unique_ptr<int>>::type,
std::unique_ptr<int>>));
EXPECT_TRUE(
(std::is_same_v<AddNonnullIfCompatible<std::shared_ptr<int>>::type,
std::shared_ptr<int>>));
EXPECT_TRUE(
(std::is_same_v<AddNonnullIfCompatible<NotSmartPtr>::type, NotSmartPtr>));
EXPECT_TRUE(
(std::is_same_v<AddNonnullIfCompatible<MySmartPtr>::type, MySmartPtr>));
}
} // namespace
} // namespace base_internal
ABSL_NAMESPACE_END
} // namespace absl