Source code
Revision control
Copy as Markdown
Other Tools
/* -*- 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
#include "mozilla/Assertions.h"
#include "mozilla/TypedEnumBits.h"
#include <stdint.h>
#include <type_traits>
// A rough feature check for is_literal_type. Not very carefully checked.
// Feel free to amend as needed. is_literal_type was removed in C++20.
// We leave ANDROID out because it's using stlport which doesn't have
// std::is_literal_type.
#if __cplusplus >= 201103L && __cplusplus < 202002L && !defined(ANDROID)
# if defined(__clang__)
/*
* Per Clang documentation, "Note that marketing version numbers should not
* be used to check for language features, as different vendors use different
* numbering schemes. Instead, use the feature checking macros."
*/
# ifndef __has_extension
# define __has_extension \
__has_feature /* compatibility, for older versions of clang */
# endif
# if __has_extension(is_literal) && __has_include(<type_traits>)
# define MOZ_HAVE_IS_LITERAL
# endif
# elif defined(__GNUC__) || defined(_MSC_VER)
# define MOZ_HAVE_IS_LITERAL
# endif
#endif
#if defined(MOZ_HAVE_IS_LITERAL) && defined(MOZ_HAVE_CXX11_CONSTEXPR)
# include <type_traits>
template <typename T>
void RequireLiteralType() {
static_assert(std::is_literal_type<T>::value, "Expected a literal type");
}
#else // not MOZ_HAVE_IS_LITERAL
template <typename T>
void RequireLiteralType() {}
#endif
template <typename T>
void RequireLiteralType(const T&) {
RequireLiteralType<T>();
}
enum class AutoEnum { A, B = -3, C };
enum class CharEnum : char { A, B = 3, C };
enum class AutoEnumBitField { A = 0x10, B = 0x20, C };
enum class CharEnumBitField : char { A = 0x10, B, C = 0x40 };
struct Nested {
enum class AutoEnum { A, B, C = -1 };
enum class CharEnum : char { A = 4, B, C = 1 };
enum class AutoEnumBitField { A, B = 0x20, C };
enum class CharEnumBitField : char { A = 1, B = 1, C = 1 };
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(AutoEnumBitField)
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(CharEnumBitField)
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(Nested::AutoEnumBitField)
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(Nested::CharEnumBitField)
#define MAKE_STANDARD_BITFIELD_FOR_TYPE(IntType) \
enum class BitFieldFor_##IntType : IntType{ \
A = 1, \
B = 2, \
C = 4, \
}; \
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(BitFieldFor_##IntType)
MAKE_STANDARD_BITFIELD_FOR_TYPE(int8_t)
MAKE_STANDARD_BITFIELD_FOR_TYPE(uint8_t)
MAKE_STANDARD_BITFIELD_FOR_TYPE(int16_t)
MAKE_STANDARD_BITFIELD_FOR_TYPE(uint16_t)
MAKE_STANDARD_BITFIELD_FOR_TYPE(int32_t)
MAKE_STANDARD_BITFIELD_FOR_TYPE(uint32_t)
MAKE_STANDARD_BITFIELD_FOR_TYPE(int64_t)
MAKE_STANDARD_BITFIELD_FOR_TYPE(uint64_t)
MAKE_STANDARD_BITFIELD_FOR_TYPE(char)
typedef signed char signed_char;
MAKE_STANDARD_BITFIELD_FOR_TYPE(signed_char)
typedef unsigned char unsigned_char;
MAKE_STANDARD_BITFIELD_FOR_TYPE(unsigned_char)
MAKE_STANDARD_BITFIELD_FOR_TYPE(short)
typedef unsigned short unsigned_short;
MAKE_STANDARD_BITFIELD_FOR_TYPE(unsigned_short)
MAKE_STANDARD_BITFIELD_FOR_TYPE(int)
typedef unsigned int unsigned_int;
MAKE_STANDARD_BITFIELD_FOR_TYPE(unsigned_int)
MAKE_STANDARD_BITFIELD_FOR_TYPE(long)
typedef unsigned long unsigned_long;
MAKE_STANDARD_BITFIELD_FOR_TYPE(unsigned_long)
typedef long long long_long;
MAKE_STANDARD_BITFIELD_FOR_TYPE(long_long)
typedef unsigned long long unsigned_long_long;
MAKE_STANDARD_BITFIELD_FOR_TYPE(unsigned_long_long)
#undef MAKE_STANDARD_BITFIELD_FOR_TYPE
template <typename T>
void TestNonConvertibilityForOneType() {
static_assert(!std::is_convertible_v<T, bool>, "should not be convertible");
static_assert(!std::is_convertible_v<T, int>, "should not be convertible");
static_assert(!std::is_convertible_v<T, uint64_t>,
"should not be convertible");
static_assert(!std::is_convertible_v<bool, T>, "should not be convertible");
static_assert(!std::is_convertible_v<int, T>, "should not be convertible");
static_assert(!std::is_convertible_v<uint64_t, T>,
"should not be convertible");
}
template <typename TypedEnum>
void TestTypedEnumBasics() {
const TypedEnum a = TypedEnum::A;
int unused = int(a);
(void)unused;
RequireLiteralType(TypedEnum::A);
RequireLiteralType(a);
TestNonConvertibilityForOneType<TypedEnum>();
}
// Op wraps a bitwise binary operator, passed as a char template parameter,
// and applies it to its arguments (aT1, aT2). For example,
//
// Op<'|'>(aT1, aT2)
//
// is the same as
//
// aT1 | aT2.
//
template <char o, typename T1, typename T2>
auto Op(const T1& aT1, const T2& aT2)
-> decltype(aT1 | aT2) // See the static_assert's below --- the return type
// depends solely on the operands type, not on the
// choice of operation.
{
static_assert(std::is_same_v<decltype(aT1 | aT2), decltype(aT1 & aT2)>,
"binary ops should have the same result type");
static_assert(std::is_same_v<decltype(aT1 | aT2), decltype(aT1 ^ aT2)>,
"binary ops should have the same result type");
static_assert(o == '|' || o == '&' || o == '^',
"unexpected operator character");
return o == '|' ? aT1 | aT2 : o == '&' ? aT1 & aT2 : aT1 ^ aT2;
}
// OpAssign wraps a bitwise binary operator, passed as a char template
// parameter, and applies the corresponding compound-assignment operator to its
// arguments (aT1, aT2). For example,
//
// OpAssign<'|'>(aT1, aT2)
//
// is the same as
//
// aT1 |= aT2.
//
template <char o, typename T1, typename T2>
T1& OpAssign(T1& aT1, const T2& aT2) {
static_assert(o == '|' || o == '&' || o == '^',
"unexpected operator character");
switch (o) {
case '|':
return aT1 |= aT2;
case '&':
return aT1 &= aT2;
case '^':
return aT1 ^= aT2;
default:
MOZ_CRASH();
}
}
// Tests a single binary bitwise operator, using a single set of three operands.
// The operations tested are:
//
// result = aT1 Op aT2;
// result Op= aT3;
//
// Where Op is the operator specified by the char template parameter 'o' and
// can be any of '|', '&', '^'.
//
// Note that the operands aT1, aT2, aT3 are intentionally passed with free
// types (separate template parameters for each) because their type may
// actually be different from TypedEnum:
//
// 1) Their type could be CastableTypedEnumResult<TypedEnum> if they are
// the result of a bitwise operation themselves;
// 2) In the non-c++11 legacy path, the type of enum values is also
// different from TypedEnum.
//
template <typename TypedEnum, char o, typename T1, typename T2, typename T3>
void TestBinOp(const T1& aT1, const T2& aT2, const T3& aT3) {
typedef typename mozilla::detail::UnsignedIntegerTypeForEnum<TypedEnum>::Type
UnsignedIntegerType;
// Part 1:
// Test the bitwise binary operator i.e.
// result = aT1 Op aT2;
auto result = Op<o>(aT1, aT2);
typedef decltype(result) ResultType;
RequireLiteralType<ResultType>();
TestNonConvertibilityForOneType<ResultType>();
UnsignedIntegerType unsignedIntegerResult =
Op<o>(UnsignedIntegerType(aT1), UnsignedIntegerType(aT2));
MOZ_RELEASE_ASSERT(unsignedIntegerResult == UnsignedIntegerType(result));
MOZ_RELEASE_ASSERT(TypedEnum(unsignedIntegerResult) == TypedEnum(result));
MOZ_RELEASE_ASSERT((!unsignedIntegerResult) == (!result));
MOZ_RELEASE_ASSERT((!!unsignedIntegerResult) == (!!result));
MOZ_RELEASE_ASSERT(bool(unsignedIntegerResult) == bool(result));
// Part 2:
// Test the compound-assignment operator, i.e.
// result Op= aT3;
TypedEnum newResult = result;
OpAssign<o>(newResult, aT3);
UnsignedIntegerType unsignedIntegerNewResult = unsignedIntegerResult;
OpAssign<o>(unsignedIntegerNewResult, UnsignedIntegerType(aT3));
MOZ_RELEASE_ASSERT(TypedEnum(unsignedIntegerNewResult) == newResult);
// Part 3:
// Test additional boolean operators that we unfortunately had to add to
// CastableTypedEnumResult at some point to please some compiler,
// even though bool convertibility should have been enough.
MOZ_RELEASE_ASSERT(result == TypedEnum(result));
MOZ_RELEASE_ASSERT(!(result != TypedEnum(result)));
MOZ_RELEASE_ASSERT((result && true) == bool(result));
MOZ_RELEASE_ASSERT((result && false) == false);
MOZ_RELEASE_ASSERT((true && result) == bool(result));
MOZ_RELEASE_ASSERT((false && result && false) == false);
MOZ_RELEASE_ASSERT((result || false) == bool(result));
MOZ_RELEASE_ASSERT((result || true) == true);
MOZ_RELEASE_ASSERT((false || result) == bool(result));
MOZ_RELEASE_ASSERT((true || result) == true);
// Part 4:
// Test short-circuit evaluation.
auto Explode = [] {
// This function should never be called. Return an arbitrary value.
MOZ_RELEASE_ASSERT(false);
return false;
};
if (result) {
MOZ_RELEASE_ASSERT(result || Explode());
MOZ_RELEASE_ASSERT(!(!result && Explode()));
} else {
MOZ_RELEASE_ASSERT(!(result && Explode()));
MOZ_RELEASE_ASSERT(!result || Explode());
}
}
// Similar to TestBinOp but testing the unary ~ operator.
template <typename TypedEnum, typename T>
void TestTilde(const T& aT) {
typedef typename mozilla::detail::UnsignedIntegerTypeForEnum<TypedEnum>::Type
UnsignedIntegerType;
auto result = ~aT;
typedef decltype(result) ResultType;
RequireLiteralType<ResultType>();
TestNonConvertibilityForOneType<ResultType>();
UnsignedIntegerType unsignedIntegerResult = ~(UnsignedIntegerType(aT));
MOZ_RELEASE_ASSERT(unsignedIntegerResult == UnsignedIntegerType(result));
MOZ_RELEASE_ASSERT(TypedEnum(unsignedIntegerResult) == TypedEnum(result));
MOZ_RELEASE_ASSERT((!unsignedIntegerResult) == (!result));
MOZ_RELEASE_ASSERT((!!unsignedIntegerResult) == (!!result));
MOZ_RELEASE_ASSERT(bool(unsignedIntegerResult) == bool(result));
}
// Helper dispatching a given triple of operands to all operator-specific
// testing functions.
template <typename TypedEnum, typename T1, typename T2, typename T3>
void TestAllOpsForGivenOperands(const T1& aT1, const T2& aT2, const T3& aT3) {
TestBinOp<TypedEnum, '|'>(aT1, aT2, aT3);
TestBinOp<TypedEnum, '&'>(aT1, aT2, aT3);
TestBinOp<TypedEnum, '^'>(aT1, aT2, aT3);
TestTilde<TypedEnum>(aT1);
}
// Helper building various triples of operands using a given operator,
// and testing all operators with them.
template <typename TypedEnum, char o>
void TestAllOpsForOperandsBuiltUsingGivenOp() {
// The type of enum values like TypedEnum::A may be different from
// TypedEnum. That is the case in the legacy non-C++11 path. We want to
// ensure good test coverage even when these two types are distinct.
// To that effect, we have both 'auto' typed variables, preserving the
// original type of enum values, and 'plain' typed variables, that
// are plain TypedEnum's.
const TypedEnum a_plain = TypedEnum::A;
const TypedEnum b_plain = TypedEnum::B;
const TypedEnum c_plain = TypedEnum::C;
auto a_auto = TypedEnum::A;
auto b_auto = TypedEnum::B;
auto c_auto = TypedEnum::C;
auto ab_plain = Op<o>(a_plain, b_plain);
auto bc_plain = Op<o>(b_plain, c_plain);
auto ab_auto = Op<o>(a_auto, b_auto);
auto bc_auto = Op<o>(b_auto, c_auto);
// On each row below, we pass a triple of operands. Keep in mind that this
// is going to be received as (aT1, aT2, aT3) and the actual tests performed
// will be of the form
//
// result = aT1 Op aT2;
// result Op= aT3;
//
// For this reason, we carefully ensure that the values of (aT1, aT2)
// systematically cover all types of such pairs; to limit complexity,
// we are not so careful with aT3, and we just try to pass aT3's
// that may lead to nontrivial bitwise operations.
TestAllOpsForGivenOperands<TypedEnum>(a_plain, b_plain, c_plain);
TestAllOpsForGivenOperands<TypedEnum>(a_plain, bc_plain, b_auto);
TestAllOpsForGivenOperands<TypedEnum>(ab_plain, c_plain, a_plain);
TestAllOpsForGivenOperands<TypedEnum>(ab_plain, bc_plain, a_auto);
TestAllOpsForGivenOperands<TypedEnum>(a_plain, b_auto, c_plain);
TestAllOpsForGivenOperands<TypedEnum>(a_plain, bc_auto, b_auto);
TestAllOpsForGivenOperands<TypedEnum>(ab_plain, c_auto, a_plain);
TestAllOpsForGivenOperands<TypedEnum>(ab_plain, bc_auto, a_auto);
TestAllOpsForGivenOperands<TypedEnum>(a_auto, b_plain, c_plain);
TestAllOpsForGivenOperands<TypedEnum>(a_auto, bc_plain, b_auto);
TestAllOpsForGivenOperands<TypedEnum>(ab_auto, c_plain, a_plain);
TestAllOpsForGivenOperands<TypedEnum>(ab_auto, bc_plain, a_auto);
TestAllOpsForGivenOperands<TypedEnum>(a_auto, b_auto, c_plain);
TestAllOpsForGivenOperands<TypedEnum>(a_auto, bc_auto, b_auto);
TestAllOpsForGivenOperands<TypedEnum>(ab_auto, c_auto, a_plain);
TestAllOpsForGivenOperands<TypedEnum>(ab_auto, bc_auto, a_auto);
}
// Tests all bitwise operations on a given TypedEnum bitfield.
template <typename TypedEnum>
void TestTypedEnumBitField() {
TestTypedEnumBasics<TypedEnum>();
TestAllOpsForOperandsBuiltUsingGivenOp<TypedEnum, '|'>();
TestAllOpsForOperandsBuiltUsingGivenOp<TypedEnum, '&'>();
TestAllOpsForOperandsBuiltUsingGivenOp<TypedEnum, '^'>();
}
// Checks that enum bitwise expressions have the same non-convertibility
// properties as c++11 enum classes do, i.e. not implicitly convertible to
// anything (though *explicitly* convertible).
void TestNoConversionsBetweenUnrelatedTypes() {
// Two typed enum classes having the same underlying integer type, to ensure
// that we would catch bugs accidentally allowing conversions in that case.
typedef CharEnumBitField T1;
typedef Nested::CharEnumBitField T2;
static_assert(!std::is_convertible_v<T1, T2>, "should not be convertible");
static_assert(!std::is_convertible_v<T1, decltype(T2::A)>,
"should not be convertible");
static_assert(!std::is_convertible_v<T1, decltype(T2::A | T2::B)>,
"should not be convertible");
static_assert(!std::is_convertible_v<decltype(T1::A), T2>,
"should not be convertible");
static_assert(!std::is_convertible_v<decltype(T1::A), decltype(T2::A)>,
"should not be convertible");
static_assert(
!std::is_convertible_v<decltype(T1::A), decltype(T2::A | T2::B)>,
"should not be convertible");
static_assert(!std::is_convertible_v<decltype(T1::A | T1::B), T2>,
"should not be convertible");
static_assert(
!std::is_convertible_v<decltype(T1::A | T1::B), decltype(T2::A)>,
"should not be convertible");
static_assert(
!std::is_convertible_v<decltype(T1::A | T1::B), decltype(T2::A | T2::B)>,
"should not be convertible");
}
enum class Int8EnumWithHighBits : int8_t { A = 0x20, B = 0x40 };
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(Int8EnumWithHighBits)
enum class Uint8EnumWithHighBits : uint8_t { A = 0x40, B = 0x80 };
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(Uint8EnumWithHighBits)
enum class Int16EnumWithHighBits : int16_t { A = 0x2000, B = 0x4000 };
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(Int16EnumWithHighBits)
enum class Uint16EnumWithHighBits : uint16_t { A = 0x4000, B = 0x8000 };
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(Uint16EnumWithHighBits)
enum class Int32EnumWithHighBits : int32_t { A = 0x20000000, B = 0x40000000 };
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(Int32EnumWithHighBits)
enum class Uint32EnumWithHighBits : uint32_t {
A = 0x40000000u,
B = 0x80000000u
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(Uint32EnumWithHighBits)
enum class Int64EnumWithHighBits : int64_t {
A = 0x2000000000000000ll,
B = 0x4000000000000000ll
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(Int64EnumWithHighBits)
enum class Uint64EnumWithHighBits : uint64_t {
A = 0x4000000000000000ull,
B = 0x8000000000000000ull
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(Uint64EnumWithHighBits)
// Checks that we don't accidentally truncate high bits by coercing to the wrong
// integer type internally when implementing bitwise ops.
template <typename EnumType, typename IntType>
void TestIsNotTruncated() {
EnumType a = EnumType::A;
EnumType b = EnumType::B;
MOZ_RELEASE_ASSERT(IntType(a));
MOZ_RELEASE_ASSERT(IntType(b));
MOZ_RELEASE_ASSERT(a | EnumType::B);
MOZ_RELEASE_ASSERT(a | b);
MOZ_RELEASE_ASSERT(EnumType::A | EnumType::B);
EnumType c = EnumType::A | EnumType::B;
MOZ_RELEASE_ASSERT(IntType(c));
MOZ_RELEASE_ASSERT(c & c);
MOZ_RELEASE_ASSERT(c | c);
MOZ_RELEASE_ASSERT(c == (EnumType::A | EnumType::B));
MOZ_RELEASE_ASSERT(a != (EnumType::A | EnumType::B));
MOZ_RELEASE_ASSERT(b != (EnumType::A | EnumType::B));
MOZ_RELEASE_ASSERT(c & EnumType::A);
MOZ_RELEASE_ASSERT(c & EnumType::B);
EnumType d = EnumType::A;
d |= EnumType::B;
MOZ_RELEASE_ASSERT(d == c);
}
int main() {
TestTypedEnumBasics<AutoEnum>();
TestTypedEnumBasics<CharEnum>();
TestTypedEnumBasics<Nested::AutoEnum>();
TestTypedEnumBasics<Nested::CharEnum>();
TestTypedEnumBitField<AutoEnumBitField>();
TestTypedEnumBitField<CharEnumBitField>();
TestTypedEnumBitField<Nested::AutoEnumBitField>();
TestTypedEnumBitField<Nested::CharEnumBitField>();
TestTypedEnumBitField<BitFieldFor_uint8_t>();
TestTypedEnumBitField<BitFieldFor_int8_t>();
TestTypedEnumBitField<BitFieldFor_uint16_t>();
TestTypedEnumBitField<BitFieldFor_int16_t>();
TestTypedEnumBitField<BitFieldFor_uint32_t>();
TestTypedEnumBitField<BitFieldFor_int32_t>();
TestTypedEnumBitField<BitFieldFor_uint64_t>();
TestTypedEnumBitField<BitFieldFor_int64_t>();
TestTypedEnumBitField<BitFieldFor_char>();
TestTypedEnumBitField<BitFieldFor_signed_char>();
TestTypedEnumBitField<BitFieldFor_unsigned_char>();
TestTypedEnumBitField<BitFieldFor_short>();
TestTypedEnumBitField<BitFieldFor_unsigned_short>();
TestTypedEnumBitField<BitFieldFor_int>();
TestTypedEnumBitField<BitFieldFor_unsigned_int>();
TestTypedEnumBitField<BitFieldFor_long>();
TestTypedEnumBitField<BitFieldFor_unsigned_long>();
TestTypedEnumBitField<BitFieldFor_long_long>();
TestTypedEnumBitField<BitFieldFor_unsigned_long_long>();
TestNoConversionsBetweenUnrelatedTypes();
TestIsNotTruncated<Int8EnumWithHighBits, int8_t>();
TestIsNotTruncated<Int16EnumWithHighBits, int16_t>();
TestIsNotTruncated<Int32EnumWithHighBits, int32_t>();
TestIsNotTruncated<Int64EnumWithHighBits, int64_t>();
TestIsNotTruncated<Uint8EnumWithHighBits, uint8_t>();
TestIsNotTruncated<Uint16EnumWithHighBits, uint16_t>();
TestIsNotTruncated<Uint32EnumWithHighBits, uint32_t>();
TestIsNotTruncated<Uint64EnumWithHighBits, uint64_t>();
return 0;
}