1 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */ 2 /* 3 * Copyright (c) 1993, 1994, 1995, 1996, 1997 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by the Computer Systems 17 * Engineering Group at Lawrence Berkeley Laboratory. 18 * 4. Neither the name of the University nor of the Laboratory may be used 19 * to endorse or promote products derived from this software without 20 * specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #ifndef lib_funcattrs_h 36 #define lib_funcattrs_h 37 38 #include "compiler-tests.h" 39 40 /* 41 * Attributes to apply to functions and their arguments, using various 42 * compiler-specific extensions. 43 */ 44 45 /* 46 * This was introduced by Clang: 47 * 48 * https://clang.llvm.org/docs/LanguageExtensions.html#has-attribute 49 * 50 * in some version (which version?); it has been picked up by GCC 5.0. 51 */ 52 #ifndef __has_attribute 53 /* 54 * It's a macro, so you can check whether it's defined to check 55 * whether it's supported. 56 * 57 * If it's not, define it to always return 0, so that we move on to 58 * the fallback checks. 59 */ 60 #define __has_attribute(x) 0 61 #endif 62 63 /* 64 * NORETURN, before a function declaration, means "this function 65 * never returns". (It must go before the function declaration, e.g. 66 * "extern NORETURN func(...)" rather than after the function 67 * declaration, as the MSVC version has to go before the declaration.) 68 */ 69 #if __has_attribute(noreturn) \ 70 || ND_IS_AT_LEAST_GNUC_VERSION(2,5) \ 71 || ND_IS_AT_LEAST_SUNC_VERSION(5,9) \ 72 || ND_IS_AT_LEAST_XL_C_VERSION(10,1) \ 73 || ND_IS_AT_LEAST_HP_C_VERSION(6,10) 74 /* 75 * Compiler with support for __attribute((noreturn)), or GCC 2.5 and 76 * later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 10.1 77 * and later (do any earlier versions of XL C support this?), or 78 * HP aCC A.06.10 and later. 79 */ 80 #define NORETURN __attribute((noreturn)) 81 82 /* 83 * However, GCC didn't support that for function *pointers* until GCC 84 * 4.1.0; see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3481. 85 * 86 * Sun C/Oracle Studio C doesn't seem to support it, either. 87 */ 88 #if (defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) < 401)) \ 89 || (defined(__SUNPRO_C)) 90 #define NORETURN_FUNCPTR 91 #else 92 #define NORETURN_FUNCPTR __attribute((noreturn)) 93 #endif 94 #elif defined(_MSC_VER) 95 /* 96 * MSVC. 97 * It doesn't allow __declspec(noreturn) to be applied to function 98 * pointers. 99 */ 100 #define NORETURN __declspec(noreturn) 101 #define NORETURN_FUNCPTR 102 #else 103 #define NORETURN 104 #define NORETURN_FUNCPTR 105 #endif 106 107 /* 108 * PRINTFLIKE(x,y), after a function declaration, means "this function 109 * does printf-style formatting, with the xth argument being the format 110 * string and the yth argument being the first argument for the format 111 * string". 112 */ 113 #if __has_attribute(__format__) \ 114 || ND_IS_AT_LEAST_GNUC_VERSION(2,3) \ 115 || ND_IS_AT_LEAST_XL_C_VERSION(10,1) \ 116 || ND_IS_AT_LEAST_HP_C_VERSION(6,10) 117 /* 118 * Compiler with support for it, or GCC 2.3 and later, or IBM XL C 10.1 119 * and later (do any earlier versions of XL C support this?), 120 * or HP aCC A.06.10 and later. 121 */ 122 #define PRINTFLIKE(x,y) __attribute__((__format__(__printf__,x,y))) 123 124 /* 125 * However, GCC didn't support that for function *pointers* until GCC 126 * 4.1.0; see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3481. 127 */ 128 #if (defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) < 401)) 129 #define PRINTFLIKE_FUNCPTR(x,y) 130 #else 131 #define PRINTFLIKE_FUNCPTR(x,y) __attribute__((__format__(__printf__,x,y))) 132 #endif 133 #else 134 #define PRINTFLIKE(x,y) 135 #define PRINTFLIKE_FUNCPTR(x,y) 136 #endif 137 138 /* 139 * For flagging arguments as format strings in MSVC. 140 */ 141 #ifdef _MSC_VER 142 #include <sal.h> 143 #define FORMAT_STRING(p) _Printf_format_string_ p 144 #else 145 #define FORMAT_STRING(p) p 146 #endif 147 148 #endif /* lib_funcattrs_h */ 149