5 * (c) 2003 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of the mLib utilities library.
12 * mLib is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU Library General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
17 * mLib is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU Library General Public License for more details.
22 * You should have received a copy of the GNU Library General Public
23 * License along with mLib; if not, write to the Free
24 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
35 /*----- Header files ------------------------------------------------------*/
37 #ifndef MLIB_COMPILER_H
38 # include "compiler.h"
41 /*----- Miscellaneous utility macros --------------------------------------*/
43 #define N(v) (sizeof(v)/sizeof(*v))
45 #define MLIB__STR(x) #x
46 #define STR(x) MLIB__STR(x)
48 #define MLIB__GLUE(x, y) x##y
49 #define GLUE(x, y) MLIB__GLUE(x, y)
51 /*----- Compiler diagnostics ----------------------------------------------*/
53 /* --- Compiler-specific definitions --- */
55 #if GCC_VERSION_P(2, 5) || CLANG_VERSION_P(3, 3)
56 # define NORETURN __attribute__((noreturn))
57 # define PRINTF_LIKE(fix, aix) __attribute__((format(printf, fix, aix)))
58 # define SCANF_LIKE(fix, aix) __attribute__((format(scanf, fix, aix)))
59 # define IGNORABLE __attribute__((unused))
62 #if GCC_VERSION_P(4, 5) || CLANG_VERSION_P(3, 3)
63 # define DEPRECATED(msg) __attribute__((deprecated(msg)))
64 #elif GCC_VERSION_P(3, 1)
65 # define DEPRECATED(msg) __attribute__((deprecated))
68 #if GCC_VERSION_P(4, 0) || CLANG_VERSION_P(3, 3)
69 # define EXECL_LIKE(ntrail) __attribute__((sentinel(ntrail)))
72 #if CLANG_VERSION_P(3, 3)
74 # define MLIB__PRAGMA_HACK(x) _Pragma(#x)
75 # define MLIB__MUFFLE_WARNINGS(warns, body) \
76 _Pragma("clang diagnostic push") \
79 _Pragma("clang diagnostic pop")
80 # define CLANG_WARNING(warn) \
81 MLIB__PRAGMA_HACK(clang diagnostic ignored warn)
82 # define MUFFLE_WARNINGS_DECL(warns, body) \
83 MLIB__MUFFLE_WARNINGS(warns, body)
84 # define MUFFLE_WARNINGS_EXPR(warns, body) \
85 __extension__ ({ MLIB__MUFFLE_WARNINGS(warns, (body);) })
86 # define MUFFLE_WARNINGS_STMT(warns, body) \
87 do { MLIB__MUFFLE_WARNINGS(warns, body) } while (0)
89 #elif GCC_VERSION_P(4, 6)
91 /* --- Diagnostic suppression in GCC: a tale of woe --- *
93 * This is extremely unpleasant, largely as a result of bugs in the GCC
94 * preprocessor's handling of @_Pragma@. The fundamental problem is
95 * that it's the preprocessor, and not the compiler proper, which
96 * detects @_Pragma@, emitting @#pragma@ lines into its output; and it
97 * does it during macro expansion, even if the macro is being expanded
98 * during argument collection. Since arguments are expanded before
99 * replacing the macro's invocation with its body, a pragma in an
100 * argument will be emitted %%\emph{before}%% any pragmata in the body,
101 * even if they appear before the argument in the body -- and even if
102 * the argument doesn't actually appear anywhere at all in the body.
104 * Another, rather less significant, problem is that @_Pragma@'s
105 * argument is a single string literal, recognized in translation phase
106 * 4, before string-literal concatenation in phase 6, so we must build
107 * pragma bodies as token lists and then stringify them.
109 * As a result, we need some subterfuge here. The @MLIB__PRAGMA_HACK@
110 * macro issues a @_Pragma@ on its argument token list, which it
111 * stringifies; this deals with the second problem. The first is
112 * trickier: we must delay expansion of @MLIB__PRAGMA_HACK@ from the
113 * argument collection phase to the body rescanning phase, and we do
114 * this by splitting the invocations between @GCC_WARNING@ macro calls:
115 * the name is left hanging from the previous call (or from
116 * @MLIB__MUFFLE_WARNINGS@, in the first case) and the body is supplied
117 * by @GCC_WARNING@, which also supplies the next @MLIB__PRAGMA_HACK@.
118 * The remaining problem is to make sure we can dispose of the final
119 * trailing @MLIB__PRAGMA_HACK@ harmlessly, which we do by introducing
120 * an extra argument @emitp@, which may be either @t@ or @nil@; this
121 * dispatches to an appropriate helper macro by means of token-pasting.
126 # define MLIB__PRAGMA_HACK_t(x) _Pragma(#x)
127 # define MLIB__PRAGMA_HACK_nil(x)
128 # define MLIB__PRAGMA_HACK(emitp, x) MLIB__PRAGMA_HACK_##emitp(x)
129 # define MLIB__MUFFLE_WARNINGS(warns, body) \
130 _Pragma("GCC diagnostic push") MLIB__PRAGMA_HACK \
134 _Pragma("GCC diagnostic pop")
135 # define GCC_WARNING(warn) \
136 (t, GCC diagnostic ignored warn) MLIB__PRAGMA_HACK
137 # define MUFFLE_WARNINGS_DECL(warns, body) \
138 MLIB__MUFFLE_WARNINGS(warns, body)
139 # define MUFFLE_WARNINGS_EXPR(warns, body) \
140 __extension__ ({ MLIB__MUFFLE_WARNINGS(warns, (body);) })
141 # define MUFFLE_WARNINGS_STMT(warns, body) \
142 do { MLIB__MUFFLE_WARNINGS(warns, body) } while (0)
145 /* --- Fallback definitions, mostly trivial --- */
148 # define DEPRECATED(msg)
152 # define EXECL_LIKE(ntrail)
156 # define DISCARD(x) do if (x); while (0)
160 # define IGNORE(x) ((void)(x))
163 #ifndef MUFFLE_WARNINGS_DECL
164 # define MUFFLE_WARNINGS_DECL(warns, body) body
167 #ifndef MUFFLE_WARNINGS_EXPR
168 # define MUFFLE_WARNINGS_EXPR(warns, body) (body)
171 #ifndef MUFFLE_WARNINGS_STMT
172 # define MUFFLE_WARNINGS_STMT(warns, body) do { body } while (0)
176 # define PRINF_LIKE(fmtix, argix)
180 # define SCANF_LIKE(fmtix, argix)
188 # define GCC_WARNING(warn)
191 #ifndef CLANG_WARNING
192 # define CLANG_WARNING(warn)
195 /*----- That's all, folks -------------------------------------------------*/