test/support/charconv_test_helpers.h - llvm-project/libcxx - Git at Google

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #ifndef SUPPORT_CHARCONV_TEST_HELPERS_H
 #define SUPPORT_CHARCONV_TEST_HELPERS_H

 #include <algorithm>
 #include <cassert>
 #include <cerrno>
 #include <charconv>
 #include <cstddef>
 #include <limits>
 #include <numeric>
 #include <string.h>
 #include <stdlib.h>
 #include <type_traits>

 #include "test_macros.h"

 #if TEST_STD_VER < 11
 #error This file requires C++11
 #endif

 using std::false_type;
 using std::true_type;

 template <typename To, typename From>
 constexpr auto
 is_non_narrowing(From a) -> decltype(To{a}, true_type())
 {
     return {};
 }

 template <typename To>
 constexpr auto
 is_non_narrowing(...) -> false_type
 {
     return {};
 }

 template <typename X, typename T>
 constexpr bool
 _fits_in(T, true_type /* non-narrowing*/, ...)
 {
     return true;
 }

 template <typename X, typename T, typename xl = std::numeric_limits<X>>
 constexpr bool
 _fits_in(T v, false_type, true_type /* T signed*/, true_type /* X signed */)
 {
     return xl::lowest() <= v && v <= (xl::max)();
 }

 template <typename X, typename T, typename xl = std::numeric_limits<X>>
 constexpr bool
 _fits_in(T v, false_type, true_type /* T signed */, false_type /* X unsigned*/)
 {
     return 0 <= v && typename std::make_unsigned<T>::type(v) <= (xl::max)();
 }

 template <typename X, typename T, typename xl = std::numeric_limits<X>>
 constexpr bool
 _fits_in(T v, false_type, false_type /* T unsigned */, ...)
 {
     return v <= typename std::make_unsigned<X>::type((xl::max)());
 }

 template <typename X, typename T>
 constexpr bool
 fits_in(T v)
 {
   return _fits_in<X>(v, is_non_narrowing<X>(v), std::is_signed<T>(), std::is_signed<X>());
 }

 template <typename X>
 struct to_chars_test_base
 {
     template <typename T, std::size_t N, typename... Ts>
     TEST_CONSTEXPR_CXX23 void test(T v, char const (&expect)[N], Ts... args)
     {
         std::to_chars_result r;

         constexpr std::size_t len = N - 1;
         static_assert(len > 0, "expected output won't be empty");

         if (!fits_in<X>(v))
             return;

         r = std::to_chars(buf, buf + len - 1, X(v), args...);
         assert(r.ptr == buf + len - 1);
         assert(r.ec == std::errc::value_too_large);

         r = std::to_chars(buf, buf + sizeof(buf), X(v), args...);
         assert(r.ptr == buf + len);
         assert(r.ec == std::errc{});
         assert(std::equal(buf, buf + len, expect));
     }

     template <typename... Ts>
     TEST_CONSTEXPR_CXX23 void test_value(X v, Ts... args)
     {
         std::to_chars_result r;

         // Poison the buffer for testing whether a successful std::to_chars
         // doesn't modify data beyond r.ptr. Use unsigned values to avoid
         // overflowing char when it's signed.
         std::iota(buf, buf + sizeof(buf), static_cast<unsigned char>(1));
         r = std::to_chars(buf, buf + sizeof(buf), v, args...);
         assert(r.ec == std::errc{});
         for (std::size_t i = r.ptr - buf; i < sizeof(buf); ++i)
             assert(static_cast<unsigned char>(buf[i]) == i + 1);
         *r.ptr = '\0';

 #ifndef TEST_HAS_NO_INT128
         if (sizeof(X) == sizeof(__int128_t)) {
             auto a = fromchars128_impl(buf, r.ptr, args...);
             assert(v == a);
         } else
 #endif
         {
             auto a = fromchars_impl(buf, r.ptr, args...);
             assert(v == a);
         }

         auto ep = r.ptr - 1;
         r = std::to_chars(buf, ep, v, args...);
         assert(r.ptr == ep);
         assert(r.ec == std::errc::value_too_large);
     }

 private:
     static TEST_CONSTEXPR_CXX23 long long fromchars_impl(char const* p, char const* ep, int base, true_type)
     {
         char* last;
         long long r;
         if (TEST_IS_CONSTANT_EVALUATED)
           last = const_cast<char*>(std::from_chars(p, ep, r, base).ptr);
         else
           r = strtoll(p, &last, base);
         assert(last == ep);

         return r;
     }

     static TEST_CONSTEXPR_CXX23 unsigned long long fromchars_impl(char const* p, char const* ep, int base, false_type)
     {
         char* last;
         unsigned long long r;
         if (TEST_IS_CONSTANT_EVALUATED)
           last = const_cast<char*>(std::from_chars(p, ep, r, base).ptr);
         else
           r = strtoull(p, &last, base);
         assert(last == ep);

         return r;
     }
 #ifndef TEST_HAS_NO_INT128
     static TEST_CONSTEXPR_CXX23 __int128_t fromchars128_impl(char const* p, char const* ep, int base, true_type)
     {
         if (!TEST_IS_CONSTANT_EVALUATED) {
             char* last;
             __int128_t r = strtoll(p, &last, base);
             if(errno != ERANGE) {
                 assert(last == ep);
                 return r;
             }
         }

         // When the value doesn't fit in a long long use from_chars. This is
         // not ideal since it does a round-trip test instead if using an
         // external source.
         __int128_t r;
         std::from_chars_result s = std::from_chars(p, ep, r, base);
         assert(s.ec == std::errc{});
         assert(s.ptr == ep);

         return r;
     }

     static TEST_CONSTEXPR_CXX23 __uint128_t fromchars128_impl(char const* p, char const* ep, int base, false_type)
     {
         if (!TEST_IS_CONSTANT_EVALUATED) {
             char* last;
             __uint128_t r = strtoull(p, &last, base);
             if(errno != ERANGE) {
                 assert(last == ep);
                 return r;
             }
         }

         __uint128_t r;
         std::from_chars_result s = std::from_chars(p, ep, r, base);
         assert(s.ec == std::errc{});
         assert(s.ptr == ep);

         return r;
     }

     static TEST_CONSTEXPR_CXX23 auto fromchars128_impl(char const* p, char const* ep, int base = 10)
     -> decltype(fromchars128_impl(p, ep, base, std::is_signed<X>()))
     {
         return fromchars128_impl(p, ep, base, std::is_signed<X>());
     }

 #endif

     static TEST_CONSTEXPR_CXX23 auto fromchars_impl(char const* p, char const* ep, int base = 10)
     -> decltype(fromchars_impl(p, ep, base, std::is_signed<X>()))
     {
         return fromchars_impl(p, ep, base, std::is_signed<X>());
     }

     char buf[150];
 };

 template <typename X>
 struct roundtrip_test_base
 {
     template <typename T, typename... Ts>
     TEST_CONSTEXPR_CXX23 void test(T v, Ts... args)
     {
         std::from_chars_result r2;
         std::to_chars_result r;
         X x = 0xc;

         if (fits_in<X>(v))
         {
             r = std::to_chars(buf, buf + sizeof(buf), v, args...);
             assert(r.ec == std::errc{});

             r2 = std::from_chars(buf, r.ptr, x, args...);
             assert(r2.ptr == r.ptr);
             assert(x == X(v));
         }
         else
         {
             r = std::to_chars(buf, buf + sizeof(buf), v, args...);
             assert(r.ec == std::errc{});

             r2 = std::from_chars(buf, r.ptr, x, args...);

             TEST_DIAGNOSTIC_PUSH
             TEST_MSVC_DIAGNOSTIC_IGNORED(4127) // conditional expression is constant

             if (std::is_signed<T>::value && v < 0 && std::is_unsigned<X>::value)
             {
                 assert(x == 0xc);
                 assert(r2.ptr == buf);
                 assert(r2.ec == std::errc::invalid_argument);
             }
             else
             {
                 assert(x == 0xc);
                 assert(r2.ptr == r.ptr);
                 assert(r2.ec == std::errc::result_out_of_range);
             }

             TEST_DIAGNOSTIC_POP
         }
     }

 private:
     char buf[150];
 };

 template <typename... T>
 struct type_list
 {
 };

 template <typename L1, typename L2>
 struct type_concat;

 template <typename... Xs, typename... Ys>
 struct type_concat<type_list<Xs...>, type_list<Ys...>>
 {
     using type = type_list<Xs..., Ys...>;
 };

 template <typename L1, typename L2>
 using concat_t = typename type_concat<L1, L2>::type;

 template <typename L1, typename L2>
 constexpr auto concat(L1, L2) -> concat_t<L1, L2>
 {
     return {};
 }

 auto all_signed = type_list<
     char,
     signed char,
     short,
     int,
     long,
     long long
 #ifndef TEST_HAS_NO_INT128
     ,
     __int128_t
 #endif
     >();
 auto all_unsigned = type_list<
     unsigned char,
     unsigned short,
     unsigned int,
     unsigned long,
     unsigned long long
 #ifndef TEST_HAS_NO_INT128
     ,
     __uint128_t
 #endif
     >();
 auto integrals = concat(all_signed, all_unsigned);

 template <template <typename> class Fn, typename... Ts>
 TEST_CONSTEXPR_CXX23 void
 run(type_list<Ts...>)
 {
     int ls[sizeof...(Ts)] = {(Fn<Ts>{}(), 0)...};
     (void)ls;
 }

 #endif // SUPPORT_CHARCONV_TEST_HELPERS_H
	//===----------------------------------------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#ifndef SUPPORT_CHARCONV_TEST_HELPERS_H
	#define SUPPORT_CHARCONV_TEST_HELPERS_H

	#include <algorithm>
	#include <cassert>
	#include <cerrno>
	#include <charconv>
	#include <cstddef>
	#include <limits>
	#include <numeric>
	#include <string.h>
	#include <stdlib.h>
	#include <type_traits>

	#include "test_macros.h"

	#if TEST_STD_VER < 11
	#error This file requires C++11
	#endif

	using std::false_type;
	using std::true_type;

	template <typename To, typename From>
	constexpr auto
	is_non_narrowing(From a) -> decltype(To{a}, true_type())
	{
	return {};
	}

	template <typename To>
	constexpr auto
	is_non_narrowing(...) -> false_type
	{
	return {};
	}

	template <typename X, typename T>
	constexpr bool
	_fits_in(T, true_type /* non-narrowing*/, ...)
	{
	return true;
	}

	template <typename X, typename T, typename xl = std::numeric_limits<X>>
	constexpr bool
	_fits_in(T v, false_type, true_type /* T signed/, true_type / X signed */)
	{
	return xl::lowest() <= v && v <= (xl::max)();
	}

	template <typename X, typename T, typename xl = std::numeric_limits<X>>
	constexpr bool
	_fits_in(T v, false_type, true_type /* T signed /, false_type / X unsigned*/)
	{
	return 0 <= v && typename std::make_unsigned<T>::type(v) <= (xl::max)();
	}

	template <typename X, typename T, typename xl = std::numeric_limits<X>>
	constexpr bool
	_fits_in(T v, false_type, false_type /* T unsigned */, ...)
	{
	return v <= typename std::make_unsigned<X>::type((xl::max)());
	}

	template <typename X, typename T>
	constexpr bool
	fits_in(T v)
	{
	return _fits_in<X>(v, is_non_narrowing<X>(v), std::is_signed<T>(), std::is_signed<X>());
	}

	template <typename X>
	struct to_chars_test_base
	{
	template <typename T, std::size_t N, typename... Ts>
	TEST_CONSTEXPR_CXX23 void test(T v, char const (&expect)[N], Ts... args)
	{
	std::to_chars_result r;

	constexpr std::size_t len = N - 1;
	static_assert(len > 0, "expected output won't be empty");

	if (!fits_in<X>(v))
	return;

	r = std::to_chars(buf, buf + len - 1, X(v), args...);
	assert(r.ptr == buf + len - 1);
	assert(r.ec == std::errc::value_too_large);

	r = std::to_chars(buf, buf + sizeof(buf), X(v), args...);
	assert(r.ptr == buf + len);
	assert(r.ec == std::errc{});
	assert(std::equal(buf, buf + len, expect));
	}

	template <typename... Ts>
	TEST_CONSTEXPR_CXX23 void test_value(X v, Ts... args)
	{
	std::to_chars_result r;

	// Poison the buffer for testing whether a successful std::to_chars
	// doesn't modify data beyond r.ptr. Use unsigned values to avoid
	// overflowing char when it's signed.
	std::iota(buf, buf + sizeof(buf), static_cast<unsigned char>(1));
	r = std::to_chars(buf, buf + sizeof(buf), v, args...);
	assert(r.ec == std::errc{});
	for (std::size_t i = r.ptr - buf; i < sizeof(buf); ++i)
	assert(static_cast<unsigned char>(buf[i]) == i + 1);
	*r.ptr = '\0';

	#ifndef TEST_HAS_NO_INT128
	if (sizeof(X) == sizeof(__int128_t)) {
	auto a = fromchars128_impl(buf, r.ptr, args...);
	assert(v == a);
	} else
	#endif
	{
	auto a = fromchars_impl(buf, r.ptr, args...);
	assert(v == a);
	}

	auto ep = r.ptr - 1;
	r = std::to_chars(buf, ep, v, args...);
	assert(r.ptr == ep);
	assert(r.ec == std::errc::value_too_large);
	}

	private:
	static TEST_CONSTEXPR_CXX23 long long fromchars_impl(char const* p, char const* ep, int base, true_type)
	{
	char* last;
	long long r;
	if (TEST_IS_CONSTANT_EVALUATED)
	last = const_cast<char*>(std::from_chars(p, ep, r, base).ptr);
	else
	r = strtoll(p, &last, base);
	assert(last == ep);

	return r;
	}

	static TEST_CONSTEXPR_CXX23 unsigned long long fromchars_impl(char const* p, char const* ep, int base, false_type)
	{
	char* last;
	unsigned long long r;
	if (TEST_IS_CONSTANT_EVALUATED)
	last = const_cast<char*>(std::from_chars(p, ep, r, base).ptr);
	else
	r = strtoull(p, &last, base);
	assert(last == ep);

	return r;
	}
	#ifndef TEST_HAS_NO_INT128
	static TEST_CONSTEXPR_CXX23 __int128_t fromchars128_impl(char const* p, char const* ep, int base, true_type)
	{
	if (!TEST_IS_CONSTANT_EVALUATED) {
	char* last;
	__int128_t r = strtoll(p, &last, base);
	if(errno != ERANGE) {
	assert(last == ep);
	return r;
	}
	}

	// When the value doesn't fit in a long long use from_chars. This is
	// not ideal since it does a round-trip test instead if using an
	// external source.
	__int128_t r;
	std::from_chars_result s = std::from_chars(p, ep, r, base);
	assert(s.ec == std::errc{});
	assert(s.ptr == ep);

	return r;
	}

	static TEST_CONSTEXPR_CXX23 __uint128_t fromchars128_impl(char const* p, char const* ep, int base, false_type)
	{
	if (!TEST_IS_CONSTANT_EVALUATED) {
	char* last;
	__uint128_t r = strtoull(p, &last, base);
	if(errno != ERANGE) {
	assert(last == ep);
	return r;
	}
	}

	__uint128_t r;
	std::from_chars_result s = std::from_chars(p, ep, r, base);
	assert(s.ec == std::errc{});
	assert(s.ptr == ep);

	return r;
	}

	static TEST_CONSTEXPR_CXX23 auto fromchars128_impl(char const* p, char const* ep, int base = 10)
	-> decltype(fromchars128_impl(p, ep, base, std::is_signed<X>()))
	{
	return fromchars128_impl(p, ep, base, std::is_signed<X>());
	}

	#endif

	static TEST_CONSTEXPR_CXX23 auto fromchars_impl(char const* p, char const* ep, int base = 10)
	-> decltype(fromchars_impl(p, ep, base, std::is_signed<X>()))
	{
	return fromchars_impl(p, ep, base, std::is_signed<X>());
	}

	char buf[150];
	};

	template <typename X>
	struct roundtrip_test_base
	{
	template <typename T, typename... Ts>
	TEST_CONSTEXPR_CXX23 void test(T v, Ts... args)
	{
	std::from_chars_result r2;
	std::to_chars_result r;
	X x = 0xc;

	if (fits_in<X>(v))
	{
	r = std::to_chars(buf, buf + sizeof(buf), v, args...);
	assert(r.ec == std::errc{});

	r2 = std::from_chars(buf, r.ptr, x, args...);
	assert(r2.ptr == r.ptr);
	assert(x == X(v));
	}
	else
	{
	r = std::to_chars(buf, buf + sizeof(buf), v, args...);
	assert(r.ec == std::errc{});

	r2 = std::from_chars(buf, r.ptr, x, args...);

	TEST_DIAGNOSTIC_PUSH
	TEST_MSVC_DIAGNOSTIC_IGNORED(4127) // conditional expression is constant

	if (std::is_signed<T>::value && v < 0 && std::is_unsigned<X>::value)
	{
	assert(x == 0xc);
	assert(r2.ptr == buf);
	assert(r2.ec == std::errc::invalid_argument);
	}
	else
	{
	assert(x == 0xc);
	assert(r2.ptr == r.ptr);
	assert(r2.ec == std::errc::result_out_of_range);
	}

	TEST_DIAGNOSTIC_POP
	}
	}

	private:
	char buf[150];
	};

	template <typename... T>
	struct type_list
	{
	};

	template <typename L1, typename L2>
	struct type_concat;

	template <typename... Xs, typename... Ys>
	struct type_concat<type_list<Xs...>, type_list<Ys...>>
	{
	using type = type_list<Xs..., Ys...>;
	};

	template <typename L1, typename L2>
	using concat_t = typename type_concat<L1, L2>::type;

	template <typename L1, typename L2>
	constexpr auto concat(L1, L2) -> concat_t<L1, L2>
	{
	return {};
	}

	auto all_signed = type_list<
	char,
	signed char,
	short,
	int,
	long,
	long long
	#ifndef TEST_HAS_NO_INT128
	,
	__int128_t
	#endif
	>();
	auto all_unsigned = type_list<
	unsigned char,
	unsigned short,
	unsigned int,
	unsigned long,
	unsigned long long
	#ifndef TEST_HAS_NO_INT128
	,
	__uint128_t
	#endif
	>();
	auto integrals = concat(all_signed, all_unsigned);

	template <template <typename> class Fn, typename... Ts>
	TEST_CONSTEXPR_CXX23 void
	run(type_list<Ts...>)
	{
	int ls[sizeof...(Ts)] = {(Fn<Ts>{}(), 0)...};
	(void)ls;
	}

	#endif // SUPPORT_CHARCONV_TEST_HELPERS_H