catch2/tests/SelfTest/UsageTests/Compilation.tests.cpp
Martin Hořeňovský 28e651f152
Move SFINAE in decomposer into return type
This is needed so that we can use conjunction and other logical
type traits to workaround issue with older GCC versions (8 and
below), when they run into types that have ambiguous constructor
from `0`, see e.g. #2571.

However, using conjunction and friends in the SFINAE constraint
in the template parameter breaks for C++20 and up, due to the new
comparison operator rewriting rules. With C++20, when the compiler
see `a == b`, it also tries `b == a` and collects overload set
for both of these expressions.

In Catch2, this means that e.g. `REQUIRE( 1 == 2 )` would lead
the compiler to check overloads for both `ExprLhs<int> == int`
and `int == ExprLhs<int>`. Since the overload set and SFINAE
constraints assume that `ExprLhs<T>` is always on the left side,
when the compiler tries to resolve the template parameters, all
hell breaks loose and the compilation fails.

By moving the SFINAE constraints to the return type, the compiler
can discard the switched expression without having to resolve
the complex SFINAE constraints, and thus everything works the
way it is supposed to.

Fixes #2571
2022-12-09 00:40:01 +01:00

356 lines
9.9 KiB
C++

// Copyright Catch2 Authors
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.txt or copy at
// https://www.boost.org/LICENSE_1_0.txt)
// SPDX-License-Identifier: BSL-1.0
#include <helpers/type_with_lit_0_comparisons.hpp>
#include <type_traits>
// Setup for #1403 -- look for global overloads of operator << for classes
// in a different namespace.
#include <ostream>
namespace foo {
struct helper_1403 {
bool operator==(helper_1403) const { return true; }
};
}
namespace bar {
template <typename... Ts>
struct TypeList {};
}
#ifdef __GNUC__
#pragma GCC diagnostic ignored "-Wmissing-declarations"
#endif
static std::ostream& operator<<(std::ostream& out, foo::helper_1403 const&) {
return out << "[1403 helper]";
}
///////////////////////////////
#include <catch2/catch_test_macros.hpp>
#include <catch2/matchers/catch_matchers_string.hpp>
#include <cstring>
// Comparison operators can return non-booleans.
// This is unusual, but should be supported.
struct logic_t {
logic_t operator< (logic_t) const { return {}; }
logic_t operator<=(logic_t) const { return {}; }
logic_t operator> (logic_t) const { return {}; }
logic_t operator>=(logic_t) const { return {}; }
logic_t operator==(logic_t) const { return {}; }
logic_t operator!=(logic_t) const { return {}; }
explicit operator bool() const { return true; }
};
static void throws_int(bool b) {
if (b) {
throw 1;
}
}
template<typename T>
bool templated_tests(T t) {
int a = 3;
REQUIRE(a == t);
CHECK(a == t);
REQUIRE_THROWS(throws_int(true));
CHECK_THROWS_AS(throws_int(true), int);
REQUIRE_NOTHROW(throws_int(false));
REQUIRE_THAT("aaa", Catch::Matchers::EndsWith("aaa"));
return true;
}
struct A {};
static std::ostream &operator<<(std::ostream &o, const A &) { return o << 0; }
struct B : private A {
bool operator==(int) const { return true; }
};
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunused-function"
#endif
#ifdef __GNUC__
// Note that because -~GCC~-, this warning cannot be silenced temporarily, by pushing diagnostic stack...
// Luckily it is firing in test files and thus can be silenced for the whole file, without losing much.
#pragma GCC diagnostic ignored "-Wunused-function"
#endif
B f();
std::ostream g();
#ifdef __clang__
#pragma clang diagnostic pop
#endif
template <typename, typename>
struct Fixture_1245 {};
// This is a minimal example for an issue we have found in 1.7.0
struct dummy_809 {
int i;
};
template<typename T>
bool operator==(const T& val, dummy_809 f) {
return val == f.i;
}
TEST_CASE("#809") {
dummy_809 f;
f.i = 42;
REQUIRE(42 == f);
}
// ------------------------------------------------------------------
// Changes to REQUIRE_THROWS_AS made it stop working in a template in
// an unfixable way (as long as C++03 compatibility is being kept).
// To prevent these from happening in the future, this needs to compile
TEST_CASE("#833") {
REQUIRE(templated_tests<int>(3));
}
// Test containing example where original stream insertable check breaks compilation
TEST_CASE("#872") {
A dummy;
CAPTURE(dummy);
B x;
REQUIRE (x == 4);
}
TEST_CASE("#1027: Bitfields can be captured") {
struct Y {
uint32_t v : 1;
};
Y y{ 0 };
REQUIRE(y.v == 0);
REQUIRE(0 == y.v);
}
// Comparison operators can return non-booleans.
// This is unusual, but should be supported.
TEST_CASE("#1147") {
logic_t t1, t2;
REQUIRE(t1 == t2);
REQUIRE(t1 != t2);
REQUIRE(t1 < t2);
REQUIRE(t1 > t2);
REQUIRE(t1 <= t2);
REQUIRE(t1 >= t2);
}
// unsigned array
TEST_CASE("#1238") {
unsigned char uarr[] = "123";
CAPTURE(uarr);
signed char sarr[] = "456";
CAPTURE(sarr);
REQUIRE(std::memcmp(uarr, "123", sizeof(uarr)) == 0);
REQUIRE(std::memcmp(sarr, "456", sizeof(sarr)) == 0);
}
TEST_CASE_METHOD((Fixture_1245<int, int>), "#1245", "[compilation]") {
SUCCEED();
}
TEST_CASE("#1403", "[compilation]") {
::foo::helper_1403 h1, h2;
REQUIRE(h1 == h2);
}
TEST_CASE("Optionally static assertions", "[compilation]") {
STATIC_REQUIRE( std::is_void<void>::value );
STATIC_REQUIRE_FALSE( std::is_void<int>::value );
STATIC_CHECK( std::is_void<void>::value );
STATIC_CHECK_FALSE( std::is_void<int>::value );
}
TEST_CASE("#1548", "[compilation]") {
using namespace bar;
REQUIRE(std::is_same<TypeList<int>, TypeList<int>>::value);
}
// #925
using signal_t = void (*) (void*);
struct TestClass {
signal_t testMethod_uponComplete_arg = nullptr;
};
namespace utility {
inline static void synchronizing_callback( void * ) { }
}
#if defined (_MSC_VER)
#pragma warning(push)
// The function pointer comparison below triggers warning because of
// calling conventions
#pragma warning(disable:4244)
#endif
TEST_CASE("#925: comparing function pointer to function address failed to compile", "[!nonportable]" ) {
TestClass test;
REQUIRE(utility::synchronizing_callback != test.testMethod_uponComplete_arg);
}
#if defined (_MSC_VER)
#pragma warning(pop)
#endif
TEST_CASE( "#1319: Sections can have description (even if it is not saved",
"[compilation]" ) {
SECTION( "SectionName", "This is a long form section description" ) {
SUCCEED();
}
}
TEST_CASE("Lambdas in assertions") {
REQUIRE([]() { return true; }());
}
namespace {
struct HasBitOperators {
int value;
friend HasBitOperators operator| (HasBitOperators lhs, HasBitOperators rhs) {
return { lhs.value | rhs.value };
}
friend HasBitOperators operator& (HasBitOperators lhs, HasBitOperators rhs) {
return { lhs.value & rhs.value };
}
friend HasBitOperators operator^ (HasBitOperators lhs, HasBitOperators rhs) {
return { lhs.value ^ rhs.value };
}
explicit operator bool() const {
return !!value;
}
friend std::ostream& operator<<(std::ostream& out, HasBitOperators val) {
out << "Val: " << val.value;
return out;
}
};
}
TEST_CASE("Assertion macros support bit operators and bool conversions", "[compilation][bitops]") {
HasBitOperators lhs{ 1 }, rhs{ 2 };
REQUIRE(lhs | rhs);
REQUIRE_FALSE(lhs & rhs);
REQUIRE(HasBitOperators{ 1 } & HasBitOperators{ 1 });
REQUIRE(lhs ^ rhs);
REQUIRE_FALSE(lhs ^ lhs);
}
namespace {
struct ImmovableType {
ImmovableType() = default;
ImmovableType(ImmovableType const&) = delete;
ImmovableType& operator=(ImmovableType const&) = delete;
ImmovableType(ImmovableType&&) = delete;
ImmovableType& operator=(ImmovableType&&) = delete;
friend bool operator==(ImmovableType const&, ImmovableType const&) {
return true;
}
};
}
TEST_CASE("Immovable types are supported in basic assertions", "[compilation][.approvals]") {
REQUIRE(ImmovableType{} == ImmovableType{});
}
namespace adl {
struct always_true {
explicit operator bool() const { return true; }
};
#define COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR(op) \
template <class T, class U> \
auto operator op (T&&, U&&) { \
return always_true{}; \
}
COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR(==)
COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR(!=)
COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR(<)
COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR(>)
COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR(<=)
COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR(>=)
COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR(|)
COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR(&)
COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR(^)
#undef COMPILATION_TEST_DEFINE_UNIVERSAL_OPERATOR
}
TEST_CASE("ADL universal operators don't hijack expression deconstruction", "[compilation][.approvals]") {
REQUIRE(adl::always_true{});
REQUIRE(0 == adl::always_true{});
REQUIRE(0 != adl::always_true{});
REQUIRE(0 < adl::always_true{});
REQUIRE(0 > adl::always_true{});
REQUIRE(0 <= adl::always_true{});
REQUIRE(0 >= adl::always_true{});
REQUIRE(0 | adl::always_true{});
REQUIRE(0 & adl::always_true{});
REQUIRE(0 ^ adl::always_true{});
}
TEST_CASE( "#2555 - types that can only be compared with 0 literal (not int/long) are supported", "[compilation][approvals]" ) {
REQUIRE( TypeWithLit0Comparisons{} < 0 );
REQUIRE_FALSE( 0 < TypeWithLit0Comparisons{} );
REQUIRE( TypeWithLit0Comparisons{} <= 0 );
REQUIRE_FALSE( 0 > TypeWithLit0Comparisons{} );
REQUIRE( TypeWithLit0Comparisons{} > 0 );
REQUIRE_FALSE( 0 > TypeWithLit0Comparisons{} );
REQUIRE( TypeWithLit0Comparisons{} >= 0 );
REQUIRE_FALSE( 0 >= TypeWithLit0Comparisons{} );
REQUIRE( TypeWithLit0Comparisons{} == 0 );
REQUIRE_FALSE( 0 == TypeWithLit0Comparisons{} );
REQUIRE( TypeWithLit0Comparisons{} != 0 );
REQUIRE_FALSE( 0 != TypeWithLit0Comparisons{} );
}
namespace {
struct MultipleImplicitConstructors {
MultipleImplicitConstructors( double ) {}
MultipleImplicitConstructors( int64_t ) {}
bool operator==( MultipleImplicitConstructors ) const { return true; }
bool operator!=( MultipleImplicitConstructors ) const { return true; }
bool operator<( MultipleImplicitConstructors ) const { return true; }
bool operator<=( MultipleImplicitConstructors ) const { return true; }
bool operator>( MultipleImplicitConstructors ) const { return true; }
bool operator>=( MultipleImplicitConstructors ) const { return true; }
};
}
TEST_CASE("#2571 - tests compile types that have multiple implicit constructors from lit 0",
"[compilation][approvals]") {
MultipleImplicitConstructors mic1( 0.0 );
MultipleImplicitConstructors mic2( 0.0 );
REQUIRE( mic1 == mic2 );
REQUIRE( mic1 != mic2 );
REQUIRE( mic1 < mic2 );
REQUIRE( mic1 <= mic2 );
REQUIRE( mic1 > mic2 );
REQUIRE( mic1 >= mic2 );
}