1 /* 2 * Copyright (C) 2013 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 #ifndef _SYS__WCHAR_LIMITS_H 29 #define _SYS__WCHAR_LIMITS_H 30 31 #include <android/api-level.h> 32 33 /* WCHAR_MIN / WCHAR_MAX can be defined by <stdint.h> or <wchar.h>. 34 * Due to historical reasons, their definition is a bit complex. 35 * 36 * - In NDK r8e and older, all definitions of WCHAR_MIN and WCHAR_MAX 37 * where 32-bit signed values (with one exception described below), 38 * despite the fact that wchar_t is 'unsigned' on ARM. 39 * See http://b.android.com/57749 40 * 41 * This is no longer the case, unless you define _WCHAR_IS_ALWAYS_SIGNED 42 * at compile time to restore the old (broken) behaviour. This doesn't 43 * affect other CPU ABIs. 44 * 45 * - Before API level 9, on ARM, wchar_t was typedef to 'char' when 46 * compiling C (not C++). Also, the definitions of WCHAR_MIN and 47 * WCHAR_MAX differed between <stdint.h> and <wchar.h>: 48 * 49 * <stdint.h> conditionally defined them to INT32_MIN / INT32_MAX. 50 * <wchar.h> conditionally defined them to 0 and 255 instead. 51 * 52 * <stdint.h> would only define WCHAR_MIN and WCHAR_MAX when: 53 * - Compiling C sources. 54 * - Compiling C++ sources with __STDC_LIMIT_MACROS being defined. 55 * 56 * <wchar.h> always ends up including <stdint.h> indirectly. This 57 * means that: 58 * 59 * - When compiling C sources, WCHAR_MIN / WCHAR_MAX were always 60 * defined as INT32_MIN / INT32_MAX. 61 * 62 * - When compiling C++ sources with __STDC_LIMIT_MACROS defined, 63 * they were always defined to INT32_MIN / INT32_MAX 64 * 65 * - When compiling C++ sources without __STDC_LIMIT_MACROS defined, 66 * they were defined by <wchar.h> as 0 and 255, respectively. 67 * 68 * Keep in mind that this was ARM-specific, only for API level < 9. 69 * 70 * If _WCHAR_IS_8BIT is defined, the same broken behaviour will 71 * be restored. See http://b.android.com/57267 72 */ 73 #if !defined(WCHAR_MIN) 74 75 # if defined(_WCHAR_IS_8BIT) && defined(__arm__) && __ANDROID_API__ < 9 76 # if defined(__cplusplus) && !defined(__STDC_LIMIT_MACROS) 77 # define WCHAR_MIN 0 78 # define WCHAR_MAX 255 79 # else 80 # define WCHAR_MIN (-2147483647 - 1) 81 # define WCHAR_MAX (2147483647) 82 # endif 83 # elif defined(_WCHAR_IS_ALWAYS_SIGNED) 84 # define WCHAR_MIN (-2147483647 - 1) 85 # define WCHAR_MAX (2147483647) 86 # else 87 /* Otherwise, the value is derived from the toolchain configuration. 88 * to avoid putting explicit CPU checks in this header. */ 89 # define WCHAR_MAX __WCHAR_MAX__ 90 91 /* Clang does not define __WCHAR_MIN__ */ 92 # if defined(__WCHAR_UNSIGNED__) 93 # define WCHAR_MIN L'\0' 94 # else 95 # define WCHAR_MIN (-(WCHAR_MAX) - 1) 96 # endif 97 # endif /* !_WCHAR_IS_ALWAYS_SIGNED */ 98 99 #endif /* !WCHAR_MIN */ 100 101 #endif /* _SYS__WCHAR_LIMITS_H */ 102