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 * NORETURN, before a function declaration, means "this function
47 * never returns".  (It must go before the function declaration, e.g.
48 * "extern NORETURN func(...)" rather than after the function
49 * declaration, as the MSVC version has to go before the declaration.)
50 */
51#if __has_attribute(noreturn) \
52    || ND_IS_AT_LEAST_GNUC_VERSION(2,5) \
53    || ND_IS_AT_LEAST_SUNC_VERSION(5,9) \
54    || ND_IS_AT_LEAST_XL_C_VERSION(10,1) \
55    || ND_IS_AT_LEAST_HP_C_VERSION(6,10)
56  /*
57   * Compiler with support for __attribute((noreturn)), or GCC 2.5 and
58   * later, or some compiler asserting compatibility with GCC 2.5 and
59   * later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 10.1
60   * and later (do any earlier versions of XL C support this?), or HP aCC
61   * A.06.10 and later.
62   */
63  #define NORETURN __attribute((noreturn))
64
65  /*
66   * However, GCC didn't support that for function *pointers* until GCC
67   * 4.1.0; see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3481.
68   *
69   * Sun C/Oracle Studio C doesn't seem to support it, either.
70   */
71  #if (defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) < 401)) \
72      || (defined(__SUNPRO_C))
73    #define NORETURN_FUNCPTR
74  #else
75    #define NORETURN_FUNCPTR __attribute((noreturn))
76  #endif
77#elif defined(_MSC_VER)
78  /*
79   * MSVC.
80   * It doesn't allow __declspec(noreturn) to be applied to function
81   * pointers.
82   */
83  #define NORETURN __declspec(noreturn)
84  #define NORETURN_FUNCPTR
85#else
86  #define NORETURN
87  #define NORETURN_FUNCPTR
88#endif
89
90/*
91 * WARN_UNUSED_RESULT, before a function declaration, means "the caller
92 * should use the result of this function" (even if it's just a success/
93 * failure indication).
94 */
95#if __has_attribute(warn_unused_result) \
96    || ND_IS_AT_LEAST_GNUC_VERSION(3,4) \
97    || ND_IS_AT_LEAST_HP_C_VERSION(6,25)
98  #define WARN_UNUSED_RESULT __attribute((warn_unused_result))
99#else
100  #define WARN_UNUSED_RESULT
101#endif
102
103/*
104 * PRINTFLIKE(x,y), after a function declaration, means "this function
105 * does printf-style formatting, with the xth argument being the format
106 * string and the yth argument being the first argument for the format
107 * string".
108 */
109#if __has_attribute(__format__) \
110    || ND_IS_AT_LEAST_GNUC_VERSION(2,3) \
111    || ND_IS_AT_LEAST_XL_C_VERSION(10,1) \
112    || ND_IS_AT_LEAST_HP_C_VERSION(6,10)
113  /*
114   * Compiler with support for it, or GCC 2.3 and later, or some compiler
115   * asserting compatibility with GCC 2.3 and later, or IBM XL C 10.1
116   * and later (do any earlier versions of XL C support this?),
117   * or HP aCC A.06.10 and later.
118   */
119  #define PRINTFLIKE(x,y) __attribute__((__format__(__printf__,x,y)))
120
121  /*
122   * However, GCC didn't support that for function *pointers* until GCC
123   * 4.1.0; see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3481.
124   * XL C 16.1 (and possibly some earlier versions, but not 12.1 or 13.1) has
125   * a similar bug, the bugfix for which was made in:
126   * * version 16.1.1.8 for Linux (25 June 2020), which fixes
127   *   https://www.ibm.com/support/pages/apar/LI81402
128   * * version 16.1.0.5 for AIX (5 May 2020), which fixes
129   *   https://www.ibm.com/support/pages/apar/IJ24678
130   *
131   * When testing versions, keep in mind that XL C 16.1 pretends to be both
132   * GCC 4.2 and Clang 4.0 at once.
133   */
134  #if (ND_IS_AT_LEAST_GNUC_VERSION(4,1) \
135       && !ND_IS_AT_LEAST_XL_C_VERSION(10,1)) \
136      || (ND_IS_AT_LEAST_XL_C_VERSION(16,1) \
137          && (ND_IS_AT_LEAST_XL_C_MODFIX(1, 8) && defined(__linux__)) \
138              || (ND_IS_AT_LEAST_XL_C_MODFIX(0, 5) && defined(_AIX)))
139    #define PRINTFLIKE_FUNCPTR(x,y) __attribute__((__format__(__printf__,x,y)))
140  #endif
141#endif
142
143#if !defined(PRINTFLIKE)
144#define PRINTFLIKE(x,y)
145#endif
146#if !defined(PRINTFLIKE_FUNCPTR)
147#define PRINTFLIKE_FUNCPTR(x,y)
148#endif
149
150/*
151 * For flagging arguments as format strings in MSVC.
152 */
153#ifdef _MSC_VER
154 #include <sal.h>
155 #define FORMAT_STRING(p) _Printf_format_string_ p
156#else
157 #define FORMAT_STRING(p) p
158#endif
159
160#endif /* lib_funcattrs_h */
161