[mLib] / utils / macros.h

/* -*-c-*-
 *
 * Handy macros
 *
 * (c) 2003 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of the mLib utilities library.
 *
 * mLib is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * mLib is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with mLib; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

#ifndef MLIB_MACROS_H
#define MLIB_MACROS_H

#ifdef __cplusplus
  extern "C" {
#endif

/*----- Header files ------------------------------------------------------*/

#include <assert.h>

#ifndef MLIB_COMPILER_H
#  include "compiler.h"
#endif

/*----- Miscellaneous utility macros --------------------------------------*/

#define N(v) (sizeof(v)/sizeof(*(v)))

#define MLIB__STR(x) #x
#define STR(x) MLIB__STR(x)

#define MLIB__GLUE(x, y) x##y
#define GLUE(x, y) MLIB__GLUE(x, y)

#ifdef static_assert
#  define STATIC_ASSERT(cond, msg) static_assert(!!(cond), msg)
#else
#  define STATIC_ASSERT(cond, msg)					\
	IGNORABLE extern char static_assert_failed[2*!!(cond) - 1]
#endif

#define COMMA ,

/*----- String and character hacks ----------------------------------------*/

#define CTYPE_HACK(func, ch) (func((unsigned char)(ch)))

#define ISALNUM(ch) CTYPE_HACK(isalnum, ch)
#define ISALPHA(ch) CTYPE_HACK(isalpha, ch)
#define ISASCII(ch) CTYPE_HACK(isascii, ch)
#define ISBLANK(ch) CTYPE_HACK(isblank, ch)
#define ISCNTRL(ch) CTYPE_HACK(iscntrl, ch)
#define ISDIGIT(ch) CTYPE_HACK(isdigit, ch)
#define ISGRAPH(ch) CTYPE_HACK(isgraph, ch)
#define ISLOWER(ch) CTYPE_HACK(islower, ch)
#define ISPRINT(ch) CTYPE_HACK(isprint, ch)
#define ISPUNCT(ch) CTYPE_HACK(ispunct, ch)
#define ISSPACE(ch) CTYPE_HACK(isspace, ch)
#define ISUPPER(ch) CTYPE_HACK(isupper, ch)
#define ISXDIGIT(ch) CTYPE_HACK(isxdigit, ch)

#define TOASCII(ch) CTYPE_HACK(toascii, ch)
#define TOLOWER(ch) CTYPE_HACK(tolower, ch)
#define TOUPPER(ch) CTYPE_HACK(toupper, ch)

#define MEMCMP(x, op, y, n) (memcmp((x), (y), (n)) op 0)
#define STRCMP(x, op, y) (strcmp((x), (y)) op 0)
#define STRNCMP(x, op, y, n) (strncmp((x), (y), (n)) op 0)

/*----- Compiler diagnostics ----------------------------------------------*/

/* --- Compiler-specific definitions --- */

#if GCC_VERSION_P(2, 5) || CLANG_VERSION_P(3, 3)
#  define NORETURN __attribute__((__noreturn__))
#  define PRINTF_LIKE(fix, aix) __attribute__((__format__(printf, fix, aix)))
#  define SCANF_LIKE(fix, aix) __attribute__((__format__(scanf, fix, aix)))
#  define IGNORABLE __attribute__((__unused__))
#endif

#if GCC_VERSION_P(3, 4) || CLANG_VERSION_P(3, 3)
#  define MUST_CHECK __attribute__((__warn_unused_result__))
#endif

#if GCC_VERSION_P(4, 5) || CLANG_VERSION_P(3, 3)
#  define DEPRECATED(msg) __attribute__((__deprecated__(msg)))
#elif GCC_VERSION_P(3, 1)
#  define DEPRECATED(msg) __attribute__((__deprecated__))
#endif

#if GCC_VERSION_P(4, 0) || CLANG_VERSION_P(3, 3)
#  define EXECL_LIKE(ntrail) __attribute__((__sentinel__(ntrail)))
#endif

#if GCC_VERSION_P(2, 7) || CLANG_VERSION_P(0, 0)
#  define LAUNDER(x)							\
	({ __typeof__(x) _y; __asm__("" : "=g"(_y) : "0"(x)); _y; })
#  define RELAX do __asm__ __volatile__("" ::: "memory"); while (0)
#endif

#if CLANG_VERSION_P(3, 3)

#  define MLIB__PRAGMA_HACK(x) _Pragma(#x)
#  define MLIB__MUFFLE_WARNINGS(warns, body)				\
	_Pragma("clang diagnostic push")				\
	warns								\
	body								\
	_Pragma("clang diagnostic pop")
#  define CLANG_WARNING(warn)						\
	MLIB__PRAGMA_HACK(clang diagnostic ignored warn)
#  define MUFFLE_WARNINGS_DECL(warns, body)				\
	MLIB__MUFFLE_WARNINGS(warns, body)
#  define MUFFLE_WARNINGS_EXPR(warns, body)				\
	__extension__ ({ MLIB__MUFFLE_WARNINGS(warns, (body);) })
#  define MUFFLE_WARNINGS_STMT(warns, body)				\
	do { MLIB__MUFFLE_WARNINGS(warns, body) } while (0)

#endif

#if GCC_VERSION_P(4, 6)

   /* --- Diagnostic suppression in GCC: a tale of woe --- *
    *
    * This is extremely unpleasant, largely as a result of bugs in the GCC
    * preprocessor's handling of @_Pragma@.  The fundamental problem is
    * that it's the preprocessor, and not the compiler proper, which
    * detects @_Pragma@, emitting @#pragma@ lines into its output; and it
    * does it during macro expansion, even if the macro is being expanded
    * during argument collection.  Since arguments are expanded before
    * replacing the macro's invocation with its body, a pragma in an
    * argument will be emitted %%\emph{before}%% any pragmata in the body,
    * even if they appear before the argument in the body -- and even if
    * the argument doesn't actually appear anywhere at all in the body.
    *
    * Another, rather less significant, problem is that @_Pragma@'s
    * argument is a single string literal, recognized in translation phase
    * 4, before string-literal concatenation in phase 6, so we must build
    * pragma bodies as token lists and then stringify them.
    *
    * As a result, we need some subterfuge here.  The @MLIB__PRAGMA_HACK@
    * macro issues a @_Pragma@ on its argument token list, which it
    * stringifies; this deals with the second problem.  The first is
    * trickier: we must delay expansion of @MLIB__PRAGMA_HACK@ from the
    * argument collection phase to the body rescanning phase, and we do
    * this by splitting the invocations between @GCC_WARNING@ macro calls:
    * the name is left hanging from the previous call (or from
    * @MLIB__MUFFLE_WARNINGS@, in the first case) and the body is supplied
    * by @GCC_WARNING@, which also supplies the next @MLIB__PRAGMA_HACK@.
    * The remaining problem is to make sure we can dispose of the final
    * trailing @MLIB__PRAGMA_HACK@ harmlessly, which we do by introducing
    * an extra argument @emitp@, which may be either @t@ or @nil@; this
    * dispatches to an appropriate helper macro by means of token-pasting.
    *
    * I'm so sorry.
    */

#  define MLIB__PRAGMA_HACK_t(x) _Pragma(#x)
#  define MLIB__PRAGMA_HACK_nil(x)
#  define MLIB__PRAGMA_HACK(emitp, x) MLIB__PRAGMA_HACK_##emitp(x)
#  define MLIB__MUFFLE_WARNINGS(warns, body)				\
	_Pragma("GCC diagnostic push") MLIB__PRAGMA_HACK		\
	warns								\
	(nil, nil)							\
	body								\
	_Pragma("GCC diagnostic pop")
#  define GCC_WARNING(warn)						\
	(t, GCC diagnostic ignored warn) MLIB__PRAGMA_HACK
#  define MUFFLE_WARNINGS_DECL(warns, body)				\
	MLIB__MUFFLE_WARNINGS(warns, body)
#  define MUFFLE_WARNINGS_EXPR(warns, body)				\
	__extension__ ({ MLIB__MUFFLE_WARNINGS(warns, (body);) })
#  define MUFFLE_WARNINGS_STMT(warns, body)				\
	do { MLIB__MUFFLE_WARNINGS(warns, body) } while (0)
#endif

/* --- Fallback definitions, mostly trivial --- */

#ifndef DEPRECATED
#  define DEPRECATED(msg)
#endif

#ifndef EXECL_LIKE
#  define EXECL_LIKE(ntrail)
#endif

#ifndef DISCARD
#  define DISCARD(x) do if (x); while (0)
#endif

#ifndef IGNORE
#  define IGNORE(x) ((void)(x))
#endif

#ifndef MUFFLE_WARNINGS_DECL
#  define MUFFLE_WARNINGS_DECL(warns, body) body
#endif

#ifndef MUFFLE_WARNINGS_EXPR
#  define MUFFLE_WARNINGS_EXPR(warns, body) (body)
#endif

#ifndef MUFFLE_WARNINGS_STMT
#  define MUFFLE_WARNINGS_STMT(warns, body) do { body } while (0)
#endif

#ifndef PRINTF_LIKE
#  define PRINF_LIKE(fmtix, argix)
#endif

#ifndef SCANF_LIKE
#  define SCANF_LIKE(fmtix, argix)
#endif

#ifndef NORETURN
#  define NORETURN
#endif

#ifndef IGNORABLE
#  define IGNORABLE
#endif

#ifndef MUST_CHECK
#  define MUST_CHECK
#endif

#ifndef LAUNDER
#  define LAUNDER
#endif

#ifndef RELAX
#  define RELAX
#endif

#ifndef GCC_WARNING
#  define GCC_WARNING(warn)
#endif

#ifndef CLANG_WARNING
#  define CLANG_WARNING(warn)
#endif

/*----- That's all, folks -------------------------------------------------*/

#ifdef __cplusplus
  }
#endif

#endif
Commit	Line	Data
14d7100d	1	/* --c--
16139d88	2	*
16139d88	3	* Handy macros
14d7100d	4	*
	5	* (c) 2003 Straylight/Edgeware
	6	*/
	7
d4efbcd9	8	/----- Licensing notice --------------------------------------------------
14d7100d	9	*
	10	* This file is part of the mLib utilities library.
	11	*
	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.
d4efbcd9	16	*
14d7100d	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.
d4efbcd9	21	*
14d7100d	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,
	25	* MA 02111-1307, USA.
	26	*/
	27
14d7100d	28	#ifndef MLIB_MACROS_H
	29	#define MLIB_MACROS_H
	30
	31	#ifdef __cplusplus
	32	extern "C" {
	33	#endif
	34
33e3ac90 MW	35	/----- Header files ------------------------------------------------------/
33e3ac90 MW	36
f50c1365 MW	37	#include <assert.h>
f50c1365 MW	38
33e3ac90 MW	39	#ifndef MLIB_COMPILER_H
	40	# include "compiler.h"
	41	#endif
	42
3832000d	43	/----- Miscellaneous utility macros --------------------------------------/
14d7100d	44
c066b1ff	45	#define N(v) (sizeof(v)/sizeof(*(v)))
14d7100d	46
16139d88	47	#define MLIB__STR(x) #x
	48	#define STR(x) MLIB__STR(x)
	49
	50	#define MLIB__GLUE(x, y) x##y
	51	#define GLUE(x, y) MLIB__GLUE(x, y)
	52
f50c1365	53	#ifdef static_assert
dd65cf2d	54	# define STATIC_ASSERT(cond, msg) static_assert(!!(cond), msg)
f50c1365 MW	55	#else
	56	# define STATIC_ASSERT(cond, msg) \
	57	IGNORABLE extern char static_assert_failed[2*!!(cond) - 1]
	58	#endif
	59
e6591bec MW	60	#define COMMA ,
e6591bec MW	61
36188114 MW	62	/----- String and character hacks ----------------------------------------/
	63
	64	#define CTYPE_HACK(func, ch) (func((unsigned char)(ch)))
	65
	66	#define ISALNUM(ch) CTYPE_HACK(isalnum, ch)
	67	#define ISALPHA(ch) CTYPE_HACK(isalpha, ch)
	68	#define ISASCII(ch) CTYPE_HACK(isascii, ch)
	69	#define ISBLANK(ch) CTYPE_HACK(isblank, ch)
	70	#define ISCNTRL(ch) CTYPE_HACK(iscntrl, ch)
	71	#define ISDIGIT(ch) CTYPE_HACK(isdigit, ch)
	72	#define ISGRAPH(ch) CTYPE_HACK(isgraph, ch)
	73	#define ISLOWER(ch) CTYPE_HACK(islower, ch)
	74	#define ISPRINT(ch) CTYPE_HACK(isprint, ch)
	75	#define ISPUNCT(ch) CTYPE_HACK(ispunct, ch)
	76	#define ISSPACE(ch) CTYPE_HACK(isspace, ch)
	77	#define ISUPPER(ch) CTYPE_HACK(isupper, ch)
	78	#define ISXDIGIT(ch) CTYPE_HACK(isxdigit, ch)
	79
	80	#define TOASCII(ch) CTYPE_HACK(toascii, ch)
	81	#define TOLOWER(ch) CTYPE_HACK(tolower, ch)
	82	#define TOUPPER(ch) CTYPE_HACK(toupper, ch)
	83
	84	#define MEMCMP(x, op, y, n) (memcmp((x), (y), (n)) op 0)
	85	#define STRCMP(x, op, y) (strcmp((x), (y)) op 0)
	86	#define STRNCMP(x, op, y, n) (strncmp((x), (y), (n)) op 0)
	87
3832000d MW	88	/----- Compiler diagnostics ----------------------------------------------/
	89
	90	/* --- Compiler-specific definitions --- */
	91
ff3d3f01	92	#if GCC_VERSION_P(2, 5) \|\| CLANG_VERSION_P(3, 3)
2eea6973 MW	93	# define NORETURN __attribute__((__noreturn__))
	94	# define PRINTF_LIKE(fix, aix) __attribute__((__format__(printf, fix, aix)))
	95	# define SCANF_LIKE(fix, aix) __attribute__((__format__(scanf, fix, aix)))
	96	# define IGNORABLE __attribute__((__unused__))
d94956b5 MW	97	#endif
d94956b5 MW	98
8c470f2a MW	99	#if GCC_VERSION_P(3, 4) \|\| CLANG_VERSION_P(3, 3)
	100	# define MUST_CHECK __attribute__((__warn_unused_result__))
	101	#endif
	102
ff3d3f01	103	#if GCC_VERSION_P(4, 5) \|\| CLANG_VERSION_P(3, 3)
2eea6973	104	# define DEPRECATED(msg) __attribute__((__deprecated__(msg)))
d94956b5	105	#elif GCC_VERSION_P(3, 1)
2eea6973	106	# define DEPRECATED(msg) __attribute__((__deprecated__))
d94956b5 MW	107	#endif
d94956b5 MW	108
ff3d3f01	109	#if GCC_VERSION_P(4, 0) \|\| CLANG_VERSION_P(3, 3)
2eea6973	110	# define EXECL_LIKE(ntrail) __attribute__((__sentinel__(ntrail)))
d94956b5 MW	111	#endif
d94956b5 MW	112
c91413e6	113	#if GCC_VERSION_P(2, 7) \|\| CLANG_VERSION_P(0, 0)
b64eb60f MW	114	# define LAUNDER(x) \
	115	({ __typeof__(x) _y; __asm__("" : "=g"(_y) : "0"(x)); _y; })
	116	# define RELAX do __asm__ __volatile__("" ::: "memory"); while (0)
	117	#endif
	118
ff3d3f01 MW	119	#if CLANG_VERSION_P(3, 3)
	120
	121	# define MLIB__PRAGMA_HACK(x) _Pragma(#x)
	122	# define MLIB__MUFFLE_WARNINGS(warns, body) \
	123	_Pragma("clang diagnostic push") \
	124	warns \
	125	body \
	126	_Pragma("clang diagnostic pop")
	127	# define CLANG_WARNING(warn) \
	128	MLIB__PRAGMA_HACK(clang diagnostic ignored warn)
	129	# define MUFFLE_WARNINGS_DECL(warns, body) \
	130	MLIB__MUFFLE_WARNINGS(warns, body)
	131	# define MUFFLE_WARNINGS_EXPR(warns, body) \
	132	__extension__ ({ MLIB__MUFFLE_WARNINGS(warns, (body);) })
	133	# define MUFFLE_WARNINGS_STMT(warns, body) \
	134	do { MLIB__MUFFLE_WARNINGS(warns, body) } while (0)
	135
c91413e6 MW	136	#endif
	137
	138	#if GCC_VERSION_P(4, 6)
d94956b5 MW	139
	140	/* --- Diagnostic suppression in GCC: a tale of woe --- *
	141	*
	142	* This is extremely unpleasant, largely as a result of bugs in the GCC
	143	* preprocessor's handling of @_Pragma@. The fundamental problem is
	144	* that it's the preprocessor, and not the compiler proper, which
	145	* detects @_Pragma@, emitting @#pragma@ lines into its output; and it
	146	* does it during macro expansion, even if the macro is being expanded
	147	* during argument collection. Since arguments are expanded before
	148	* replacing the macro's invocation with its body, a pragma in an
	149	* argument will be emitted %%\emph{before}%% any pragmata in the body,
	150	* even if they appear before the argument in the body -- and even if
	151	* the argument doesn't actually appear anywhere at all in the body.
	152	*
	153	* Another, rather less significant, problem is that @_Pragma@'s
	154	* argument is a single string literal, recognized in translation phase
	155	* 4, before string-literal concatenation in phase 6, so we must build
	156	* pragma bodies as token lists and then stringify them.
	157	*
	158	* As a result, we need some subterfuge here. The @MLIB__PRAGMA_HACK@
	159	* macro issues a @_Pragma@ on its argument token list, which it
	160	* stringifies; this deals with the second problem. The first is
	161	* trickier: we must delay expansion of @MLIB__PRAGMA_HACK@ from the
	162	* argument collection phase to the body rescanning phase, and we do
	163	* this by splitting the invocations between @GCC_WARNING@ macro calls:
	164	* the name is left hanging from the previous call (or from
	165	* @MLIB__MUFFLE_WARNINGS@, in the first case) and the body is supplied
	166	* by @GCC_WARNING@, which also supplies the next @MLIB__PRAGMA_HACK@.
	167	* The remaining problem is to make sure we can dispose of the final
	168	* trailing @MLIB__PRAGMA_HACK@ harmlessly, which we do by introducing
	169	* an extra argument @emitp@, which may be either @t@ or @nil@; this
	170	* dispatches to an appropriate helper macro by means of token-pasting.
	171	*
	172	* I'm so sorry.
	173	*/
	174
	175	# define MLIB__PRAGMA_HACK_t(x) _Pragma(#x)
	176	# define MLIB__PRAGMA_HACK_nil(x)
	177	# define MLIB__PRAGMA_HACK(emitp, x) MLIB__PRAGMA_HACK_##emitp(x)
	178	# define MLIB__MUFFLE_WARNINGS(warns, body) \
3832000d MW	179	_Pragma("GCC diagnostic push") MLIB__PRAGMA_HACK \
	180	warns \
	181	(nil, nil) \
	182	body \
	183	_Pragma("GCC diagnostic pop")
d94956b5	184	# define GCC_WARNING(warn) \
3832000d	185	(t, GCC diagnostic ignored warn) MLIB__PRAGMA_HACK
d94956b5	186	# define MUFFLE_WARNINGS_DECL(warns, body) \
3832000d	187	MLIB__MUFFLE_WARNINGS(warns, body)
d94956b5	188	# define MUFFLE_WARNINGS_EXPR(warns, body) \
3832000d	189	__extension__ ({ MLIB__MUFFLE_WARNINGS(warns, (body);) })
d94956b5	190	# define MUFFLE_WARNINGS_STMT(warns, body) \
3832000d	191	do { MLIB__MUFFLE_WARNINGS(warns, body) } while (0)
3832000d MW	192	#endif
	193
	194	/* --- Fallback definitions, mostly trivial --- */
	195
3832000d MW	196	#ifndef DEPRECATED
	197	# define DEPRECATED(msg)
	198	#endif
	199
	200	#ifndef EXECL_LIKE
	201	# define EXECL_LIKE(ntrail)
	202	#endif
	203
	204	#ifndef DISCARD
	205	# define DISCARD(x) do if (x); while (0)
	206	#endif
	207
	208	#ifndef IGNORE
	209	# define IGNORE(x) ((void)(x))
	210	#endif
	211
	212	#ifndef MUFFLE_WARNINGS_DECL
	213	# define MUFFLE_WARNINGS_DECL(warns, body) body
	214	#endif
	215
	216	#ifndef MUFFLE_WARNINGS_EXPR
	217	# define MUFFLE_WARNINGS_EXPR(warns, body) (body)
	218	#endif
	219
	220	#ifndef MUFFLE_WARNINGS_STMT
	221	# define MUFFLE_WARNINGS_STMT(warns, body) do { body } while (0)
	222	#endif
	223
	224	#ifndef PRINTF_LIKE
	225	# define PRINF_LIKE(fmtix, argix)
	226	#endif
	227
	228	#ifndef SCANF_LIKE
	229	# define SCANF_LIKE(fmtix, argix)
	230	#endif
	231
59eae7fd MW	232	#ifndef NORETURN
	233	# define NORETURN
	234	#endif
	235
3832000d MW	236	#ifndef IGNORABLE
	237	# define IGNORABLE
	238	#endif
	239
8c470f2a MW	240	#ifndef MUST_CHECK
	241	# define MUST_CHECK
	242	#endif
	243
b64eb60f MW	244	#ifndef LAUNDER
	245	# define LAUNDER
	246	#endif
	247
	248	#ifndef RELAX
	249	# define RELAX
	250	#endif
	251
3832000d MW	252	#ifndef GCC_WARNING
	253	# define GCC_WARNING(warn)
	254	#endif
	255
ff3d3f01 MW	256	#ifndef CLANG_WARNING
	257	# define CLANG_WARNING(warn)
	258	#endif
	259
14d7100d	260	/----- That's all, folks -------------------------------------------------/
	261
	262	#ifdef __cplusplus
	263	}
	264	#endif
	265
	266	#endif