tests/uchar_test.cpp - platform/bionic.git - Git at Google

 /*
  * Copyright (C) 2014 The Android Open Source Project
  *
  * 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
  *
  *      http://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 <uchar.h>

 #include <gtest/gtest.h>

 #include <errno.h>
 #include <limits.h>
 #include <locale.h>
 #include <stdint.h>

 #include "utils.h"

 // Modern versions of UTF-8 (https://datatracker.ietf.org/doc/html/rfc3629 and
 // newer) explicitly disallow code points beyond U+10FFFF, which exclude all 5-
 // and 6-byte sequences. Earlier versions of UTF-8 allowed the wider range:
 // https://datatracker.ietf.org/doc/html/rfc2279.
 //
 // Bionic's unicode implementation was written after the high values were
 // excluded, so it has never supported them. Other implementations (at least
 // as of glibc 2.36), do support those sequences.
 #if defined(__ANDROID__) || defined(ANDROID_HOST_MUSL)
 constexpr bool kLibcRejectsOverLongUtf8Sequences = true;
 #elif defined(__GLIBC__)
 constexpr bool kLibcRejectsOverLongUtf8Sequences = false;
 #else
 #error kLibcRejectsOverLongUtf8Sequences must be configured for this platform
 #endif

 TEST(uchar, sizeof_uchar_t) {
   EXPECT_EQ(2U, sizeof(char16_t));
   EXPECT_EQ(4U, sizeof(char32_t));
 }

 TEST(uchar, start_state) {
   // C23 does not appear to specify the behavior of the conversion functions if
   // a state is reused before the character is completed. In the wchar.h section
   // (7.31.6.3) it says:
   //
   //     If an mbstate_t object has been altered by any of the functions
   //     described in this subclause, and is then used with a different
   //     multibyte character sequence, or in the other conversion direction, or
   //     with a different LC_CTYPE category setting than on earlier function
   //     calls, the behavior is undefined.
   //
   // But "described in this subclause" refers to the wchar.h functions, not the
   // uchar.h ones.
   //
   // Since C has no opinion, we need to make a choice. While no caller should
   // ever do this (what does it mean to begin decoding a UTF-32 character while
   // still in the middle of a UTF-8 sequence?), considering that a decoding
   // error seems the least surprising. Bionic and glibc both have that behavior.
   // musl ignores the state (it also doesn't make much sense to read the state
   // when the entire conversion completes in a single call) and decodes the
   // UTF-32 character.
 #if !defined(ANDROID_HOST_MUSL)
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   char out[MB_LEN_MAX];
   mbstate_t ps;

   memset(&ps, 0, sizeof(ps));
   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(nullptr, "\xc2", 1, &ps));
   errno = 0;
   EXPECT_EQ(static_cast<size_t>(-1), c32rtomb(out, 0x00a2, &ps));
   EXPECT_ERRNO(EILSEQ);

   // Similarly (but not in compliance with the standard afaict), musl seems to
   // ignore the state entirely for the UTF-32 functions rather than reset it.

   // If the first argument to c32rtomb is nullptr or the second is L'\0' the shift
   // state should be reset.
   memset(&ps, 0, sizeof(ps));
   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(nullptr, "\xc2", 1, &ps));
   EXPECT_EQ(1U, c32rtomb(nullptr, 0x00a2, &ps));
   EXPECT_TRUE(mbsinit(&ps));

   memset(&ps, 0, sizeof(ps));
   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(nullptr, "\xf0\xa4", 1, &ps));
   EXPECT_EQ(1U, c32rtomb(out, L'\0', &ps));
   EXPECT_TRUE(mbsinit(&ps));
 #endif
 }

 TEST(uchar, c16rtomb_null_out) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   EXPECT_EQ(1U, c16rtomb(nullptr, L'\0', nullptr));
   EXPECT_EQ(1U, c16rtomb(nullptr, L'h', nullptr));
 }

 TEST(uchar, c16rtomb_null_char) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   char bytes[MB_LEN_MAX];
   EXPECT_EQ(1U, c16rtomb(bytes, L'\0', nullptr));
 }

 TEST(uchar, c16rtomb) {
   char bytes[MB_LEN_MAX];

   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(1U, c16rtomb(bytes, L'h', nullptr));
   EXPECT_EQ('h', bytes[0]);

   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   // 1-byte UTF-8.
   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(1U, c16rtomb(bytes, L'h', nullptr));
   EXPECT_EQ('h', bytes[0]);
   // 2-byte UTF-8.
   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(2U, c16rtomb(bytes, 0x00a2, nullptr));
   EXPECT_EQ('\xc2', bytes[0]);
   EXPECT_EQ('\xa2', bytes[1]);
   // 3-byte UTF-8.
   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(3U, c16rtomb(bytes, 0x20ac, nullptr));
   EXPECT_EQ('\xe2', bytes[0]);
   EXPECT_EQ('\x82', bytes[1]);
   EXPECT_EQ('\xac', bytes[2]);
   // 4-byte UTF-8 from a surrogate pair...
   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(0U, c16rtomb(bytes, 0xdbea, nullptr));
   EXPECT_EQ(4U, c16rtomb(bytes, 0xdfcd, nullptr));
   EXPECT_EQ('\xf4', bytes[0]);
   EXPECT_EQ('\x8a', bytes[1]);
   EXPECT_EQ('\xaf', bytes[2]);
   EXPECT_EQ('\x8d', bytes[3]);
 }

 TEST(uchar, c16rtomb_invalid) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   char bytes[MB_LEN_MAX];

   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(static_cast<size_t>(-1), c16rtomb(bytes, 0xdfcd, nullptr));

   EXPECT_EQ(0U, c16rtomb(bytes, 0xdbea, nullptr));
   EXPECT_EQ(static_cast<size_t>(-1), c16rtomb(bytes, 0xdbea, nullptr));
 }

 TEST(uchar, mbrtoc16_null) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   ASSERT_EQ(0U, mbrtoc16(nullptr, nullptr, 0, nullptr));
 }

 TEST(uchar, mbrtoc16_zero_len) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   char16_t out;

   out = L'x';
   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "hello", 0, nullptr));
   EXPECT_EQ(L'x', out);

   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "hello", 0, nullptr));
   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "", 0, nullptr));
   EXPECT_EQ(1U, mbrtoc16(&out, "hello", 1, nullptr));
   EXPECT_EQ(L'h', out);
 }

 TEST(uchar, mbrtoc16) {
   char16_t out;

   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   // 1-byte UTF-8.
   ASSERT_EQ(1U, mbrtoc16(&out, "abcdef", 6, nullptr));
   ASSERT_EQ(L'a', out);
   // 2-byte UTF-8.
   ASSERT_EQ(2U, mbrtoc16(&out, "\xc2\xa2" "cdef", 6, nullptr));
   ASSERT_EQ(static_cast<char16_t>(0x00a2), out);
   // 3-byte UTF-8.
   ASSERT_EQ(3U, mbrtoc16(&out, "\xe2\x82\xac" "def", 6, nullptr));
   ASSERT_EQ(static_cast<char16_t>(0x20ac), out);
   // 4-byte UTF-8 will be returned as a surrogate pair...
   ASSERT_EQ(4U, mbrtoc16(&out, "\xf4\x8a\xaf\x8d", 6, nullptr));
   ASSERT_EQ(static_cast<char16_t>(0xdbea), out);
   ASSERT_EQ(static_cast<size_t>(-3), mbrtoc16(&out,
                                               "\xf4\x8a\xaf\x8d"
                                               "ef",
                                               6, nullptr));
   ASSERT_EQ(static_cast<char16_t>(0xdfcd), out);
 }

 TEST(uchar, mbrtoc16_long_sequences) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   char16_t out = u'\0';
   errno = 0;
   auto result = mbrtoc16(&out, "\xf8\xa1\xa2\xa3\xa4", 5, nullptr);
   if (kLibcRejectsOverLongUtf8Sequences) {
     EXPECT_EQ(static_cast<size_t>(-1), result);
     EXPECT_ERRNO(EILSEQ);
     EXPECT_EQ(u'\0', out);
   } else {
     EXPECT_EQ(5U, result);
     EXPECT_ERRNO(0);
     EXPECT_EQ(u'\uf94a', out);
   }
 }

 TEST(uchar, mbrtoc16_reserved_range) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   errno = 0;
   char16_t out = u'\0';
   EXPECT_EQ(static_cast<size_t>(-1), mbrtoc16(&out, "\xf0\x80\xbf\xbf", 6, nullptr));
   EXPECT_EQ(u'\0', out);
   EXPECT_ERRNO(EILSEQ);
 }

 TEST(uchar, mbrtoc16_beyond_range) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   errno = 0;
   char16_t out = u'\0';
   auto result = mbrtoc16(&out, "\xf5\x80\x80\x80", 6, nullptr);
   if (kLibcRejectsOverLongUtf8Sequences) {
     EXPECT_EQ(static_cast<size_t>(-1), result);
     EXPECT_EQ(u'\0', out);
     EXPECT_ERRNO(EILSEQ);
   } else {
     EXPECT_EQ(4U, result);
     EXPECT_EQ(u'\xdcc0', out);
     EXPECT_ERRNO(0);
   }
 }

 void test_mbrtoc16_incomplete(mbstate_t* ps) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   char16_t out;
   // 2-byte UTF-8.
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\xc2", 1, ps));
   ASSERT_EQ(1U, mbrtoc16(&out, "\xa2" "cdef", 5, ps));
   ASSERT_EQ(static_cast<char16_t>(0x00a2), out);
   ASSERT_TRUE(mbsinit(ps));
   // 3-byte UTF-8.
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\xe2", 1, ps));
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\x82", 1, ps));
   ASSERT_EQ(1U, mbrtoc16(&out, "\xac" "def", 4, ps));
   ASSERT_EQ(static_cast<char16_t>(0x20ac), out);
   ASSERT_TRUE(mbsinit(ps));
   // 4-byte UTF-8.
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\xf4", 1, ps));
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\x8a\xaf", 2, ps));
   ASSERT_EQ(1U, mbrtoc16(&out,
                          "\x8d"
                          "ef",
                          3, ps));
   ASSERT_EQ(static_cast<char16_t>(0xdbea), out);
   ASSERT_EQ(static_cast<size_t>(-3), mbrtoc16(&out,
                                               "\x80"
                                               "ef",
                                               3, ps));
   ASSERT_EQ(static_cast<char16_t>(0xdfcd), out);
   ASSERT_TRUE(mbsinit(ps));

   // Invalid 2-byte
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\xc2", 1, ps));
   errno = 0;
   ASSERT_EQ(static_cast<size_t>(-1), mbrtoc16(&out, "\x20" "cdef", 5, ps));
   ASSERT_ERRNO(EILSEQ);
 }

 TEST(uchar, mbrtoc16_incomplete) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   mbstate_t ps;
   memset(&ps, 0, sizeof(ps));

   test_mbrtoc16_incomplete(&ps);
   test_mbrtoc16_incomplete(nullptr);
 }

 TEST(uchar, c32rtomb) {
   EXPECT_EQ(1U, c32rtomb(nullptr, L'\0', nullptr));
   EXPECT_EQ(1U, c32rtomb(nullptr, L'h', nullptr));

   char bytes[MB_LEN_MAX];

   memset(bytes, 1, sizeof(bytes));
   EXPECT_EQ(1U, c32rtomb(bytes, L'\0', nullptr));
   EXPECT_EQ('\0', bytes[0]);
   EXPECT_EQ('\x01', bytes[1]);

   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(1U, c32rtomb(bytes, L'h', nullptr));
   EXPECT_EQ('h', bytes[0]);

   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   // 1-byte UTF-8.
   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(1U, c32rtomb(bytes, L'h', nullptr));
   EXPECT_EQ('h', bytes[0]);
   // 2-byte UTF-8.
   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(2U, c32rtomb(bytes, 0x00a2, nullptr));
   EXPECT_EQ('\xc2', bytes[0]);
   EXPECT_EQ('\xa2', bytes[1]);
   // 3-byte UTF-8.
   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(3U, c32rtomb(bytes, 0x20ac, nullptr));
   EXPECT_EQ('\xe2', bytes[0]);
   EXPECT_EQ('\x82', bytes[1]);
   EXPECT_EQ('\xac', bytes[2]);
   // 4-byte UTF-8.
   memset(bytes, 0, sizeof(bytes));
   EXPECT_EQ(4U, c32rtomb(bytes, 0x24b62, nullptr));
   EXPECT_EQ('\xf0', bytes[0]);
   EXPECT_EQ('\xa4', bytes[1]);
   EXPECT_EQ('\xad', bytes[2]);
   EXPECT_EQ('\xa2', bytes[3]);
   // Invalid code point.
   errno = 0;
   EXPECT_EQ(static_cast<size_t>(-1), c32rtomb(bytes, 0xffffffff, nullptr));
   EXPECT_ERRNO(EILSEQ);
 }

 TEST(uchar, mbrtoc32_valid_non_characters) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   char32_t out[8] = {};
   ASSERT_EQ(3U, mbrtoc32(out, "\xef\xbf\xbe", 3, nullptr));
   ASSERT_EQ(0xfffeU, out[0]);
   ASSERT_EQ(3U, mbrtoc32(out, "\xef\xbf\xbf", 3, nullptr));
   ASSERT_EQ(0xffffU, out[0]);
 }

 TEST(uchar, mbrtoc32_out_of_range) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   char32_t out = U'\0';
   errno = 0;
   auto result = mbrtoc32(&out, "\xf5\x80\x80\x80", 4, nullptr);
   if (kLibcRejectsOverLongUtf8Sequences) {
     EXPECT_EQ(static_cast<size_t>(-1), result);
     EXPECT_ERRNO(EILSEQ);
     EXPECT_EQ(U'\0', out);
   } else {
     EXPECT_EQ(4U, result);
     EXPECT_ERRNO(0);
     EXPECT_EQ(U'\x140000', out);
   }
 }

 TEST(uchar, mbrtoc32) {
   char32_t out[8];

   out[0] = L'x';
   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(out, "hello", 0, nullptr));
   EXPECT_EQ(static_cast<char32_t>(L'x'), out[0]);

   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(out, "hello", 0, nullptr));
   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(out, "", 0, nullptr));
   EXPECT_EQ(1U, mbrtoc32(out, "hello", 1, nullptr));
   EXPECT_EQ(static_cast<char32_t>(L'h'), out[0]);

   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(nullptr, "hello", 0, nullptr));
   EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(nullptr, "", 0, nullptr));
   EXPECT_EQ(1U, mbrtoc32(nullptr, "hello", 1, nullptr));

   EXPECT_EQ(0U, mbrtoc32(nullptr, nullptr, 0, nullptr));

   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   // 1-byte UTF-8.
   EXPECT_EQ(1U, mbrtoc32(out, "abcdef", 6, nullptr));
   EXPECT_EQ(static_cast<char32_t>(L'a'), out[0]);
   // 2-byte UTF-8.
   EXPECT_EQ(2U, mbrtoc32(out,
                          "\xc2\xa2"
                          "cdef",
                          6, nullptr));
   EXPECT_EQ(static_cast<char32_t>(0x00a2), out[0]);
   // 3-byte UTF-8.
   EXPECT_EQ(3U, mbrtoc32(out,
                          "\xe2\x82\xac"
                          "def",
                          6, nullptr));
   EXPECT_EQ(static_cast<char32_t>(0x20ac), out[0]);
   // 4-byte UTF-8.
   EXPECT_EQ(4U, mbrtoc32(out,
                          "\xf0\xa4\xad\xa2"
                          "ef",
                          6, nullptr));
   EXPECT_EQ(static_cast<char32_t>(0x24b62), out[0]);
 #if defined(__BIONIC__) // glibc allows this.
   // Illegal 5-byte UTF-8.
   errno = 0;
   EXPECT_EQ(static_cast<size_t>(-1), mbrtoc32(out,
                                               "\xf8\xa1\xa2\xa3\xa4"
                                               "f",
                                               6, nullptr));
   EXPECT_ERRNO(EILSEQ);
 #endif
   // Illegal over-long sequence.
   errno = 0;
   EXPECT_EQ(static_cast<size_t>(-1), mbrtoc32(out,
                                               "\xf0\x82\x82\xac"
                                               "ef",
                                               6, nullptr));
   EXPECT_ERRNO(EILSEQ);
 }

 void test_mbrtoc32_incomplete(mbstate_t* ps) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   char32_t out;
   // 2-byte UTF-8.
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\xc2", 1, ps));
   ASSERT_EQ(1U, mbrtoc32(&out, "\xa2" "cdef", 5, ps));
   ASSERT_EQ(static_cast<char32_t>(0x00a2), out);
   ASSERT_TRUE(mbsinit(ps));
   // 3-byte UTF-8.
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\xe2", 1, ps));
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\x82", 1, ps));
   ASSERT_EQ(1U, mbrtoc32(&out, "\xac" "def", 4, ps));
   ASSERT_EQ(static_cast<char32_t>(0x20ac), out);
   ASSERT_TRUE(mbsinit(ps));
   // 4-byte UTF-8.
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\xf0", 1, ps));
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\xa4\xad", 2, ps));
   ASSERT_EQ(1U, mbrtoc32(&out, "\xa2" "ef", 3, ps));
   ASSERT_EQ(static_cast<char32_t>(0x24b62), out);
   ASSERT_TRUE(mbsinit(ps));

   // Invalid 2-byte
   ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\xc2", 1, ps));
   errno = 0;
   ASSERT_EQ(static_cast<size_t>(-1), mbrtoc32(&out, "\x20" "cdef", 5, ps));
   ASSERT_ERRNO(EILSEQ);
 }

 TEST(uchar, mbrtoc32_incomplete) {
   ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
   uselocale(LC_GLOBAL_LOCALE);

   mbstate_t ps;
   memset(&ps, 0, sizeof(ps));

   test_mbrtoc32_incomplete(&ps);
   test_mbrtoc32_incomplete(nullptr);
 }
	/*
	* Copyright (C) 2014 The Android Open Source Project
	*
	* 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
	*
	* http://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 <uchar.h>

	#include <gtest/gtest.h>

	#include <errno.h>
	#include <limits.h>
	#include <locale.h>
	#include <stdint.h>

	#include "utils.h"

	// Modern versions of UTF-8 (https://datatracker.ietf.org/doc/html/rfc3629 and
	// newer) explicitly disallow code points beyond U+10FFFF, which exclude all 5-
	// and 6-byte sequences. Earlier versions of UTF-8 allowed the wider range:
	// https://datatracker.ietf.org/doc/html/rfc2279.
	//
	// Bionic's unicode implementation was written after the high values were
	// excluded, so it has never supported them. Other implementations (at least
	// as of glibc 2.36), do support those sequences.
	#if defined(__ANDROID__) \|\| defined(ANDROID_HOST_MUSL)
	constexpr bool kLibcRejectsOverLongUtf8Sequences = true;
	#elif defined(__GLIBC__)
	constexpr bool kLibcRejectsOverLongUtf8Sequences = false;
	#else
	#error kLibcRejectsOverLongUtf8Sequences must be configured for this platform
	#endif

	TEST(uchar, sizeof_uchar_t) {
	EXPECT_EQ(2U, sizeof(char16_t));
	EXPECT_EQ(4U, sizeof(char32_t));
	}

	TEST(uchar, start_state) {
	// C23 does not appear to specify the behavior of the conversion functions if
	// a state is reused before the character is completed. In the wchar.h section
	// (7.31.6.3) it says:
	//
	// If an mbstate_t object has been altered by any of the functions
	// described in this subclause, and is then used with a different
	// multibyte character sequence, or in the other conversion direction, or
	// with a different LC_CTYPE category setting than on earlier function
	// calls, the behavior is undefined.
	//
	// But "described in this subclause" refers to the wchar.h functions, not the
	// uchar.h ones.
	//
	// Since C has no opinion, we need to make a choice. While no caller should
	// ever do this (what does it mean to begin decoding a UTF-32 character while
	// still in the middle of a UTF-8 sequence?), considering that a decoding
	// error seems the least surprising. Bionic and glibc both have that behavior.
	// musl ignores the state (it also doesn't make much sense to read the state
	// when the entire conversion completes in a single call) and decodes the
	// UTF-32 character.
	#if !defined(ANDROID_HOST_MUSL)
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	char out[MB_LEN_MAX];
	mbstate_t ps;

	memset(&ps, 0, sizeof(ps));
	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(nullptr, "\xc2", 1, &ps));
	errno = 0;
	EXPECT_EQ(static_cast<size_t>(-1), c32rtomb(out, 0x00a2, &ps));
	EXPECT_ERRNO(EILSEQ);

	// Similarly (but not in compliance with the standard afaict), musl seems to
	// ignore the state entirely for the UTF-32 functions rather than reset it.

	// If the first argument to c32rtomb is nullptr or the second is L'\0' the shift
	// state should be reset.
	memset(&ps, 0, sizeof(ps));
	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(nullptr, "\xc2", 1, &ps));
	EXPECT_EQ(1U, c32rtomb(nullptr, 0x00a2, &ps));
	EXPECT_TRUE(mbsinit(&ps));

	memset(&ps, 0, sizeof(ps));
	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(nullptr, "\xf0\xa4", 1, &ps));
	EXPECT_EQ(1U, c32rtomb(out, L'\0', &ps));
	EXPECT_TRUE(mbsinit(&ps));
	#endif
	}

	TEST(uchar, c16rtomb_null_out) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	EXPECT_EQ(1U, c16rtomb(nullptr, L'\0', nullptr));
	EXPECT_EQ(1U, c16rtomb(nullptr, L'h', nullptr));
	}

	TEST(uchar, c16rtomb_null_char) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	char bytes[MB_LEN_MAX];
	EXPECT_EQ(1U, c16rtomb(bytes, L'\0', nullptr));
	}

	TEST(uchar, c16rtomb) {
	char bytes[MB_LEN_MAX];

	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(1U, c16rtomb(bytes, L'h', nullptr));
	EXPECT_EQ('h', bytes[0]);

	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	// 1-byte UTF-8.
	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(1U, c16rtomb(bytes, L'h', nullptr));
	EXPECT_EQ('h', bytes[0]);
	// 2-byte UTF-8.
	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(2U, c16rtomb(bytes, 0x00a2, nullptr));
	EXPECT_EQ('\xc2', bytes[0]);
	EXPECT_EQ('\xa2', bytes[1]);
	// 3-byte UTF-8.
	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(3U, c16rtomb(bytes, 0x20ac, nullptr));
	EXPECT_EQ('\xe2', bytes[0]);
	EXPECT_EQ('\x82', bytes[1]);
	EXPECT_EQ('\xac', bytes[2]);
	// 4-byte UTF-8 from a surrogate pair...
	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(0U, c16rtomb(bytes, 0xdbea, nullptr));
	EXPECT_EQ(4U, c16rtomb(bytes, 0xdfcd, nullptr));
	EXPECT_EQ('\xf4', bytes[0]);
	EXPECT_EQ('\x8a', bytes[1]);
	EXPECT_EQ('\xaf', bytes[2]);
	EXPECT_EQ('\x8d', bytes[3]);
	}

	TEST(uchar, c16rtomb_invalid) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	char bytes[MB_LEN_MAX];

	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(static_cast<size_t>(-1), c16rtomb(bytes, 0xdfcd, nullptr));

	EXPECT_EQ(0U, c16rtomb(bytes, 0xdbea, nullptr));
	EXPECT_EQ(static_cast<size_t>(-1), c16rtomb(bytes, 0xdbea, nullptr));
	}

	TEST(uchar, mbrtoc16_null) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	ASSERT_EQ(0U, mbrtoc16(nullptr, nullptr, 0, nullptr));
	}

	TEST(uchar, mbrtoc16_zero_len) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	char16_t out;

	out = L'x';
	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "hello", 0, nullptr));
	EXPECT_EQ(L'x', out);

	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "hello", 0, nullptr));
	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "", 0, nullptr));
	EXPECT_EQ(1U, mbrtoc16(&out, "hello", 1, nullptr));
	EXPECT_EQ(L'h', out);
	}

	TEST(uchar, mbrtoc16) {
	char16_t out;

	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	// 1-byte UTF-8.
	ASSERT_EQ(1U, mbrtoc16(&out, "abcdef", 6, nullptr));
	ASSERT_EQ(L'a', out);
	// 2-byte UTF-8.
	ASSERT_EQ(2U, mbrtoc16(&out, "\xc2\xa2" "cdef", 6, nullptr));
	ASSERT_EQ(static_cast<char16_t>(0x00a2), out);
	// 3-byte UTF-8.
	ASSERT_EQ(3U, mbrtoc16(&out, "\xe2\x82\xac" "def", 6, nullptr));
	ASSERT_EQ(static_cast<char16_t>(0x20ac), out);
	// 4-byte UTF-8 will be returned as a surrogate pair...
	ASSERT_EQ(4U, mbrtoc16(&out, "\xf4\x8a\xaf\x8d", 6, nullptr));
	ASSERT_EQ(static_cast<char16_t>(0xdbea), out);
	ASSERT_EQ(static_cast<size_t>(-3), mbrtoc16(&out,
	"\xf4\x8a\xaf\x8d"
	"ef",
	6, nullptr));
	ASSERT_EQ(static_cast<char16_t>(0xdfcd), out);
	}

	TEST(uchar, mbrtoc16_long_sequences) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	char16_t out = u'\0';
	errno = 0;
	auto result = mbrtoc16(&out, "\xf8\xa1\xa2\xa3\xa4", 5, nullptr);
	if (kLibcRejectsOverLongUtf8Sequences) {
	EXPECT_EQ(static_cast<size_t>(-1), result);
	EXPECT_ERRNO(EILSEQ);
	EXPECT_EQ(u'\0', out);
	} else {
	EXPECT_EQ(5U, result);
	EXPECT_ERRNO(0);
	EXPECT_EQ(u'\uf94a', out);
	}
	}

	TEST(uchar, mbrtoc16_reserved_range) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	errno = 0;
	char16_t out = u'\0';
	EXPECT_EQ(static_cast<size_t>(-1), mbrtoc16(&out, "\xf0\x80\xbf\xbf", 6, nullptr));
	EXPECT_EQ(u'\0', out);
	EXPECT_ERRNO(EILSEQ);
	}

	TEST(uchar, mbrtoc16_beyond_range) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	errno = 0;
	char16_t out = u'\0';
	auto result = mbrtoc16(&out, "\xf5\x80\x80\x80", 6, nullptr);
	if (kLibcRejectsOverLongUtf8Sequences) {
	EXPECT_EQ(static_cast<size_t>(-1), result);
	EXPECT_EQ(u'\0', out);
	EXPECT_ERRNO(EILSEQ);
	} else {
	EXPECT_EQ(4U, result);
	EXPECT_EQ(u'\xdcc0', out);
	EXPECT_ERRNO(0);
	}
	}

	void test_mbrtoc16_incomplete(mbstate_t* ps) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	char16_t out;
	// 2-byte UTF-8.
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\xc2", 1, ps));
	ASSERT_EQ(1U, mbrtoc16(&out, "\xa2" "cdef", 5, ps));
	ASSERT_EQ(static_cast<char16_t>(0x00a2), out);
	ASSERT_TRUE(mbsinit(ps));
	// 3-byte UTF-8.
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\xe2", 1, ps));
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\x82", 1, ps));
	ASSERT_EQ(1U, mbrtoc16(&out, "\xac" "def", 4, ps));
	ASSERT_EQ(static_cast<char16_t>(0x20ac), out);
	ASSERT_TRUE(mbsinit(ps));
	// 4-byte UTF-8.
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\xf4", 1, ps));
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\x8a\xaf", 2, ps));
	ASSERT_EQ(1U, mbrtoc16(&out,
	"\x8d"
	"ef",
	3, ps));
	ASSERT_EQ(static_cast<char16_t>(0xdbea), out);
	ASSERT_EQ(static_cast<size_t>(-3), mbrtoc16(&out,
	"\x80"
	"ef",
	3, ps));
	ASSERT_EQ(static_cast<char16_t>(0xdfcd), out);
	ASSERT_TRUE(mbsinit(ps));

	// Invalid 2-byte
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc16(&out, "\xc2", 1, ps));
	errno = 0;
	ASSERT_EQ(static_cast<size_t>(-1), mbrtoc16(&out, "\x20" "cdef", 5, ps));
	ASSERT_ERRNO(EILSEQ);
	}

	TEST(uchar, mbrtoc16_incomplete) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	mbstate_t ps;
	memset(&ps, 0, sizeof(ps));

	test_mbrtoc16_incomplete(&ps);
	test_mbrtoc16_incomplete(nullptr);
	}

	TEST(uchar, c32rtomb) {
	EXPECT_EQ(1U, c32rtomb(nullptr, L'\0', nullptr));
	EXPECT_EQ(1U, c32rtomb(nullptr, L'h', nullptr));

	char bytes[MB_LEN_MAX];

	memset(bytes, 1, sizeof(bytes));
	EXPECT_EQ(1U, c32rtomb(bytes, L'\0', nullptr));
	EXPECT_EQ('\0', bytes[0]);
	EXPECT_EQ('\x01', bytes[1]);

	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(1U, c32rtomb(bytes, L'h', nullptr));
	EXPECT_EQ('h', bytes[0]);

	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	// 1-byte UTF-8.
	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(1U, c32rtomb(bytes, L'h', nullptr));
	EXPECT_EQ('h', bytes[0]);
	// 2-byte UTF-8.
	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(2U, c32rtomb(bytes, 0x00a2, nullptr));
	EXPECT_EQ('\xc2', bytes[0]);
	EXPECT_EQ('\xa2', bytes[1]);
	// 3-byte UTF-8.
	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(3U, c32rtomb(bytes, 0x20ac, nullptr));
	EXPECT_EQ('\xe2', bytes[0]);
	EXPECT_EQ('\x82', bytes[1]);
	EXPECT_EQ('\xac', bytes[2]);
	// 4-byte UTF-8.
	memset(bytes, 0, sizeof(bytes));
	EXPECT_EQ(4U, c32rtomb(bytes, 0x24b62, nullptr));
	EXPECT_EQ('\xf0', bytes[0]);
	EXPECT_EQ('\xa4', bytes[1]);
	EXPECT_EQ('\xad', bytes[2]);
	EXPECT_EQ('\xa2', bytes[3]);
	// Invalid code point.
	errno = 0;
	EXPECT_EQ(static_cast<size_t>(-1), c32rtomb(bytes, 0xffffffff, nullptr));
	EXPECT_ERRNO(EILSEQ);
	}

	TEST(uchar, mbrtoc32_valid_non_characters) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	char32_t out[8] = {};
	ASSERT_EQ(3U, mbrtoc32(out, "\xef\xbf\xbe", 3, nullptr));
	ASSERT_EQ(0xfffeU, out[0]);
	ASSERT_EQ(3U, mbrtoc32(out, "\xef\xbf\xbf", 3, nullptr));
	ASSERT_EQ(0xffffU, out[0]);
	}

	TEST(uchar, mbrtoc32_out_of_range) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	char32_t out = U'\0';
	errno = 0;
	auto result = mbrtoc32(&out, "\xf5\x80\x80\x80", 4, nullptr);
	if (kLibcRejectsOverLongUtf8Sequences) {
	EXPECT_EQ(static_cast<size_t>(-1), result);
	EXPECT_ERRNO(EILSEQ);
	EXPECT_EQ(U'\0', out);
	} else {
	EXPECT_EQ(4U, result);
	EXPECT_ERRNO(0);
	EXPECT_EQ(U'\x140000', out);
	}
	}

	TEST(uchar, mbrtoc32) {
	char32_t out[8];

	out[0] = L'x';
	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(out, "hello", 0, nullptr));
	EXPECT_EQ(static_cast<char32_t>(L'x'), out[0]);

	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(out, "hello", 0, nullptr));
	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(out, "", 0, nullptr));
	EXPECT_EQ(1U, mbrtoc32(out, "hello", 1, nullptr));
	EXPECT_EQ(static_cast<char32_t>(L'h'), out[0]);

	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(nullptr, "hello", 0, nullptr));
	EXPECT_EQ(static_cast<size_t>(-2), mbrtoc32(nullptr, "", 0, nullptr));
	EXPECT_EQ(1U, mbrtoc32(nullptr, "hello", 1, nullptr));

	EXPECT_EQ(0U, mbrtoc32(nullptr, nullptr, 0, nullptr));

	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	// 1-byte UTF-8.
	EXPECT_EQ(1U, mbrtoc32(out, "abcdef", 6, nullptr));
	EXPECT_EQ(static_cast<char32_t>(L'a'), out[0]);
	// 2-byte UTF-8.
	EXPECT_EQ(2U, mbrtoc32(out,
	"\xc2\xa2"
	"cdef",
	6, nullptr));
	EXPECT_EQ(static_cast<char32_t>(0x00a2), out[0]);
	// 3-byte UTF-8.
	EXPECT_EQ(3U, mbrtoc32(out,
	"\xe2\x82\xac"
	"def",
	6, nullptr));
	EXPECT_EQ(static_cast<char32_t>(0x20ac), out[0]);
	// 4-byte UTF-8.
	EXPECT_EQ(4U, mbrtoc32(out,
	"\xf0\xa4\xad\xa2"
	"ef",
	6, nullptr));
	EXPECT_EQ(static_cast<char32_t>(0x24b62), out[0]);
	#if defined(__BIONIC__) // glibc allows this.
	// Illegal 5-byte UTF-8.
	errno = 0;
	EXPECT_EQ(static_cast<size_t>(-1), mbrtoc32(out,
	"\xf8\xa1\xa2\xa3\xa4"
	"f",
	6, nullptr));
	EXPECT_ERRNO(EILSEQ);
	#endif
	// Illegal over-long sequence.
	errno = 0;
	EXPECT_EQ(static_cast<size_t>(-1), mbrtoc32(out,
	"\xf0\x82\x82\xac"
	"ef",
	6, nullptr));
	EXPECT_ERRNO(EILSEQ);
	}

	void test_mbrtoc32_incomplete(mbstate_t* ps) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	char32_t out;
	// 2-byte UTF-8.
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\xc2", 1, ps));
	ASSERT_EQ(1U, mbrtoc32(&out, "\xa2" "cdef", 5, ps));
	ASSERT_EQ(static_cast<char32_t>(0x00a2), out);
	ASSERT_TRUE(mbsinit(ps));
	// 3-byte UTF-8.
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\xe2", 1, ps));
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\x82", 1, ps));
	ASSERT_EQ(1U, mbrtoc32(&out, "\xac" "def", 4, ps));
	ASSERT_EQ(static_cast<char32_t>(0x20ac), out);
	ASSERT_TRUE(mbsinit(ps));
	// 4-byte UTF-8.
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\xf0", 1, ps));
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\xa4\xad", 2, ps));
	ASSERT_EQ(1U, mbrtoc32(&out, "\xa2" "ef", 3, ps));
	ASSERT_EQ(static_cast<char32_t>(0x24b62), out);
	ASSERT_TRUE(mbsinit(ps));

	// Invalid 2-byte
	ASSERT_EQ(static_cast<size_t>(-2), mbrtoc32(&out, "\xc2", 1, ps));
	errno = 0;
	ASSERT_EQ(static_cast<size_t>(-1), mbrtoc32(&out, "\x20" "cdef", 5, ps));
	ASSERT_ERRNO(EILSEQ);
	}

	TEST(uchar, mbrtoc32_incomplete) {
	ASSERT_STREQ("C.UTF-8", setlocale(LC_CTYPE, "C.UTF-8"));
	uselocale(LC_GLOBAL_LOCALE);

	mbstate_t ps;
	memset(&ps, 0, sizeof(ps));

	test_mbrtoc32_incomplete(&ps);
	test_mbrtoc32_incomplete(nullptr);
	}