glib/gmacros.h

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  20  * file for a list of people on the GLib Team.  See the ChangeLog
  21  * files for a list of changes.  These files are distributed with
  22  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  23  */
  24
  25 /* This file must not include any other glib header file and must thus
  26  * not refer to variables from glibconfig.h
  27  */
  28
  29 #ifndef __G_MACROS_H__
  30 #define __G_MACROS_H__
  31
  32 #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  33 #error "Only <glib.h> can be included directly."
  34 #endif
  35
  36 /* We include stddef.h to get the system's definition of NULL
  37  */
  38 #include <stddef.h>
  39
  40 #define G_GNUC_CHECK_VERSION(major, minor) \
  41     (defined(__GNUC__) && \
  42      ((__GNUC__ > (major)) || \
  43       ((__GNUC__ == (major)) && \
  44        (__GNUC_MINOR__ >= (minor)))))
  45
  46 /* Here we provide G_GNUC_EXTENSION as an alias for __extension__,
  47  * where this is valid. This allows for warningless compilation of
  48  * "long long" types even in the presence of '-ansi -pedantic'.
  49  */
  50 #if     __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)
  51 #define G_GNUC_EXTENSION __extension__
  52 #else
  53 #define G_GNUC_EXTENSION
  54 #endif
  55
  56 /* Every compiler that we target supports inlining, but some of them may
  57  * complain about it if we don't say "__inline".  If we have C99, then
  58  * we can use "inline" directly.  Otherwise, we say "__inline" to avoid
  59  * the warning.
  60  */
  61 #define G_CAN_INLINE
  62 #if !defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199900)
  63 #undef inline
  64 #define inline __inline
  65 #endif
  66
  67 /* For historical reasons we need to continue to support those who
  68  * define G_IMPLEMENT_INLINES to mean "don't implement this here".
  69  */
  70 #ifdef G_IMPLEMENT_INLINES
  71 #  define G_INLINE_FUNC extern
  72 #  undef  G_CAN_INLINE
  73 #else
  74 #  define G_INLINE_FUNC static inline
  75 #endif /* G_IMPLEMENT_INLINES */
  76
  77 /* Provide macros to feature the GCC function attribute.
  78  */
  79 #if    __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
  80 #define G_GNUC_PURE __attribute__((__pure__))
  81 #define G_GNUC_MALLOC __attribute__((__malloc__))
  82 #else
  83 #define G_GNUC_PURE
  84 #define G_GNUC_MALLOC
  85 #endif
  86
  87 #if     __GNUC__ >= 4
  88 #define G_GNUC_NULL_TERMINATED __attribute__((__sentinel__))
  89 #else
  90 #define G_GNUC_NULL_TERMINATED
  91 #endif
  92
  93 /* Clang feature detection: http://clang.llvm.org/docs/LanguageExtensions.html */
  94 #ifndef __has_feature
  95 #define __has_feature(x) 0
  96 #endif
  97
  98 #ifndef __has_builtin
  99 #define __has_builtin(x) 0
 100 #endif
 101
 102 #if     (!defined(__clang__) && ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))) || \
 103         (defined(__clang__) && __has_feature(__alloc_size__))
 104 #define G_GNUC_ALLOC_SIZE(x) __attribute__((__alloc_size__(x)))
 105 #define G_GNUC_ALLOC_SIZE2(x,y) __attribute__((__alloc_size__(x,y)))
 106 #else
 107 #define G_GNUC_ALLOC_SIZE(x)
 108 #define G_GNUC_ALLOC_SIZE2(x,y)
 109 #endif
 110
 111 #if     __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
 112 #define G_GNUC_PRINTF( format_idx, arg_idx )    \
 113   __attribute__((__format__ (__printf__, format_idx, arg_idx)))
 114 #define G_GNUC_SCANF( format_idx, arg_idx )     \
 115   __attribute__((__format__ (__scanf__, format_idx, arg_idx)))
 116 #define G_GNUC_FORMAT( arg_idx )                \
 117   __attribute__((__format_arg__ (arg_idx)))
 118 #define G_GNUC_NORETURN                         \
 119   __attribute__((__noreturn__))
 120 #define G_GNUC_CONST                            \
 121   __attribute__((__const__))
 122 #define G_GNUC_UNUSED                           \
 123   __attribute__((__unused__))
 124 #define G_GNUC_NO_INSTRUMENT                    \
 125   __attribute__((__no_instrument_function__))
 126 #else   /* !__GNUC__ */
 127 #define G_GNUC_PRINTF( format_idx, arg_idx )
 128 #define G_GNUC_SCANF( format_idx, arg_idx )
 129 #define G_GNUC_FORMAT( arg_idx )
 130 #define G_GNUC_NORETURN
 131 #define G_GNUC_CONST
 132 #define G_GNUC_UNUSED
 133 #define G_GNUC_NO_INSTRUMENT
 134 #endif  /* !__GNUC__ */
 135
 136 #if    __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
 137 #define G_GNUC_DEPRECATED __attribute__((__deprecated__))
 138 #else
 139 #define G_GNUC_DEPRECATED
 140 #endif /* __GNUC__ */
 141
 142 #if    __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
 143 #define G_GNUC_DEPRECATED_FOR(f)                        \
 144   __attribute__((deprecated("Use " #f " instead")))
 145 #else
 146 #define G_GNUC_DEPRECATED_FOR(f)        G_GNUC_DEPRECATED
 147 #endif /* __GNUC__ */
 148
 149 #if    __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
 150 #define G_GNUC_BEGIN_IGNORE_DEPRECATIONS                \
 151   _Pragma ("GCC diagnostic push")                       \
 152   _Pragma ("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
 153 #define G_GNUC_END_IGNORE_DEPRECATIONS                  \
 154   _Pragma ("GCC diagnostic pop")
 155 #elif defined (_MSC_VER) && (_MSC_VER >= 1500)
 156 #define G_GNUC_BEGIN_IGNORE_DEPRECATIONS                \
 157   __pragma (warning (push))  \
 158   __pragma (warning (disable : 4996))
 159 #define G_GNUC_END_IGNORE_DEPRECATIONS                  \
 160   __pragma (warning (pop))
 161 #elif defined (__clang__)
 162 #define G_GNUC_BEGIN_IGNORE_DEPRECATIONS \
 163   _Pragma("clang diagnostic push") \
 164   _Pragma("clang diagnostic ignored \"-Wdeprecated-declarations\"")
 165 #define G_GNUC_END_IGNORE_DEPRECATIONS \
 166   _Pragma("clang diagnostic pop")
 167 #else
 168 #define G_GNUC_BEGIN_IGNORE_DEPRECATIONS
 169 #define G_GNUC_END_IGNORE_DEPRECATIONS
 170 #endif
 171
 172 #if     __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 3)
 173 #define G_GNUC_MAY_ALIAS __attribute__((may_alias))
 174 #else
 175 #define G_GNUC_MAY_ALIAS
 176 #endif
 177
 178 #if    __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
 179 #define G_GNUC_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
 180 #else
 181 #define G_GNUC_WARN_UNUSED_RESULT
 182 #endif /* __GNUC__ */
 183
 184 #ifndef G_DISABLE_DEPRECATED
 185 /* Wrap the gcc __PRETTY_FUNCTION__ and __FUNCTION__ variables with
 186  * macros, so we can refer to them as strings unconditionally.
 187  * usage not-recommended since gcc-3.0
 188  */
 189 #if defined (__GNUC__) && (__GNUC__ < 3)
 190 #define G_GNUC_FUNCTION         __FUNCTION__
 191 #define G_GNUC_PRETTY_FUNCTION  __PRETTY_FUNCTION__
 192 #else   /* !__GNUC__ */
 193 #define G_GNUC_FUNCTION         ""
 194 #define G_GNUC_PRETTY_FUNCTION  ""
 195 #endif  /* !__GNUC__ */
 196 #endif  /* !G_DISABLE_DEPRECATED */
 197
 198 #if __has_feature(attribute_analyzer_noreturn) && defined(__clang_analyzer__)
 199 #define G_ANALYZER_ANALYZING 1
 200 #define G_ANALYZER_NORETURN __attribute__((analyzer_noreturn))
 201 #else
 202 #define G_ANALYZER_ANALYZING 0
 203 #define G_ANALYZER_NORETURN
 204 #endif
 205
 206 #define G_STRINGIFY(macro_or_string)    G_STRINGIFY_ARG (macro_or_string)
 207 #define G_STRINGIFY_ARG(contents)       #contents
 208
 209 #ifndef __GI_SCANNER__ /* The static assert macro really confuses the introspection parser */
 210 #define G_PASTE_ARGS(identifier1,identifier2) identifier1 ## identifier2
 211 #define G_PASTE(identifier1,identifier2)      G_PASTE_ARGS (identifier1, identifier2)
 212 #ifdef __COUNTER__
 213 #define G_STATIC_ASSERT(expr) typedef char G_PASTE (_GStaticAssertCompileTimeAssertion_, __COUNTER__)[(expr) ? 1 : -1] G_GNUC_UNUSED
 214 #else
 215 #define G_STATIC_ASSERT(expr) typedef char G_PASTE (_GStaticAssertCompileTimeAssertion_, __LINE__)[(expr) ? 1 : -1] G_GNUC_UNUSED
 216 #endif
 217 #define G_STATIC_ASSERT_EXPR(expr) ((void) sizeof (char[(expr) ? 1 : -1]))
 218 #endif
 219
 220 /* Provide a string identifying the current code position */
 221 #if defined(__GNUC__) && (__GNUC__ < 3) && !defined(__cplusplus)
 222 #define G_STRLOC        __FILE__ ":" G_STRINGIFY (__LINE__) ":" __PRETTY_FUNCTION__ "()"
 223 #else
 224 #define G_STRLOC        __FILE__ ":" G_STRINGIFY (__LINE__)
 225 #endif
 226
 227 /* Provide a string identifying the current function, non-concatenatable */
 228 #if defined (__GNUC__) && defined (__cplusplus)
 229 #define G_STRFUNC     ((const char*) (__PRETTY_FUNCTION__))
 230 #elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
 231 #define G_STRFUNC     ((const char*) (__func__))
 232 #elif defined (__GNUC__) || (defined(_MSC_VER) && (_MSC_VER > 1300))
 233 #define G_STRFUNC     ((const char*) (__FUNCTION__))
 234 #else
 235 #define G_STRFUNC     ((const char*) ("???"))
 236 #endif
 237
 238 /* Guard C code in headers, while including them from C++ */
 239 #ifdef  __cplusplus
 240 #define G_BEGIN_DECLS  extern "C" {
 241 #define G_END_DECLS    }
 242 #else
 243 #define G_BEGIN_DECLS
 244 #define G_END_DECLS
 245 #endif
 246
 247 /* Provide definitions for some commonly used macros.
 248  *  Some of them are only provided if they haven't already
 249  *  been defined. It is assumed that if they are already
 250  *  defined then the current definition is correct.
 251  */
 252 #ifndef NULL
 253 #  ifdef __cplusplus
 254 #  define NULL        (0L)
 255 #  else /* !__cplusplus */
 256 #  define NULL        ((void*) 0)
 257 #  endif /* !__cplusplus */
 258 #endif
 259
 260 #ifndef FALSE
 261 #define FALSE   (0)
 262 #endif
 263
 264 #ifndef TRUE
 265 #define TRUE    (!FALSE)
 266 #endif
 267
 268 #undef  MAX
 269 #define MAX(a, b)  (((a) > (b)) ? (a) : (b))
 270
 271 #undef  MIN
 272 #define MIN(a, b)  (((a) < (b)) ? (a) : (b))
 273
 274 #undef  ABS
 275 #define ABS(a)     (((a) < 0) ? -(a) : (a))
 276
 277 #undef  CLAMP
 278 #define CLAMP(x, low, high)  (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))
 279
 280 /* Count the number of elements in an array. The array must be defined
 281  * as such; using this with a dynamically allocated array will give
 282  * incorrect results.
 283  */
 284 #define G_N_ELEMENTS(arr)               (sizeof (arr) / sizeof ((arr)[0]))
 285
 286 /* Macros by analogy to GINT_TO_POINTER, GPOINTER_TO_INT
 287  */
 288 #define GPOINTER_TO_SIZE(p)     ((gsize) (p))
 289 #define GSIZE_TO_POINTER(s)     ((gpointer) (gsize) (s))
 290
 291 /* Provide convenience macros for handling structure
 292  * fields through their offsets.
 293  */
 294
 295 #if defined(__GNUC__)  && __GNUC__ >= 4
 296 #define G_STRUCT_OFFSET(struct_type, member) \
 297       ((glong) offsetof (struct_type, member))
 298 #else
 299 #define G_STRUCT_OFFSET(struct_type, member)    \
 300       ((glong) ((guint8*) &((struct_type*) 0)->member))
 301 #endif
 302
 303 #define G_STRUCT_MEMBER_P(struct_p, struct_offset)   \
 304     ((gpointer) ((guint8*) (struct_p) + (glong) (struct_offset)))
 305 #define G_STRUCT_MEMBER(member_type, struct_p, struct_offset)   \
 306     (*(member_type*) G_STRUCT_MEMBER_P ((struct_p), (struct_offset)))
 307
 308 /* Provide simple macro statement wrappers:
 309  *   G_STMT_START { statements; } G_STMT_END;
 310  * This can be used as a single statement, like:
 311  *   if (x) G_STMT_START { ... } G_STMT_END; else ...
 312  * This intentionally does not use compiler extensions like GCC's '({...})' to
 313  * avoid portability issue or side effects when compiled with different compilers.
 314  * MSVC complains about "while(0)": C4127: "Conditional expression is constant",
 315  * so we use __pragma to avoid the warning since the use here is intentional.
 316  */
 317 #if !(defined (G_STMT_START) && defined (G_STMT_END))
 318 #define G_STMT_START  do
 319 #if defined (_MSC_VER) && (_MSC_VER >= 1500)
 320 #define G_STMT_END \
 321     __pragma(warning(push)) \
 322     __pragma(warning(disable:4127)) \
 323     while(0) \
 324     __pragma(warning(pop))
 325 #else
 326 #define G_STMT_END    while (0)
 327 #endif
 328 #endif
 329
 330 /* Deprecated -- do not use. */
 331 #ifndef G_DISABLE_DEPRECATED
 332 #ifdef G_DISABLE_CONST_RETURNS
 333 #define G_CONST_RETURN
 334 #else
 335 #define G_CONST_RETURN const
 336 #endif
 337 #endif
 338
 339 /*
 340  * The G_LIKELY and G_UNLIKELY macros let the programmer give hints to
 341  * the compiler about the expected result of an expression. Some compilers
 342  * can use this information for optimizations.
 343  *
 344  * The _G_BOOLEAN_EXPR macro is intended to trigger a gcc warning when
 345  * putting assignments in g_return_if_fail ().
 346  */
 347 #if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
 348 #define _G_BOOLEAN_EXPR(expr)                   \
 349  G_GNUC_EXTENSION ({                            \
 350    int _g_boolean_var_;                         \
 351    if (expr)                                    \
 352       _g_boolean_var_ = 1;                      \
 353    else                                         \
 354       _g_boolean_var_ = 0;                      \
 355    _g_boolean_var_;                             \
 356 })
 357 #define G_LIKELY(expr) (__builtin_expect (_G_BOOLEAN_EXPR(expr), 1))
 358 #define G_UNLIKELY(expr) (__builtin_expect (_G_BOOLEAN_EXPR(expr), 0))
 359 #else
 360 #define G_LIKELY(expr) (expr)
 361 #define G_UNLIKELY(expr) (expr)
 362 #endif
 363
 364 #if    __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
 365 #define G_DEPRECATED __attribute__((__deprecated__))
 366 #elif defined(_MSC_VER) && (_MSC_VER >= 1300)
 367 #define G_DEPRECATED __declspec(deprecated)
 368 #else
 369 #define G_DEPRECATED
 370 #endif
 371
 372 #if    __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
 373 #define G_DEPRECATED_FOR(f) __attribute__((__deprecated__("Use '" #f "' instead")))
 374 #elif defined(_MSC_FULL_VER) && (_MSC_FULL_VER > 140050320)
 375 #define G_DEPRECATED_FOR(f) __declspec(deprecated("is deprecated. Use '" #f "' instead"))
 376 #else
 377 #define G_DEPRECATED_FOR(f) G_DEPRECATED
 378 #endif
 379
 380 #if    __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
 381 #define G_UNAVAILABLE(maj,min) __attribute__((deprecated("Not available before " #maj "." #min)))
 382 #elif defined(_MSC_FULL_VER) && (_MSC_FULL_VER > 140050320)
 383 #define G_UNAVAILABLE(maj,min) __declspec(deprecated("is not available before " #maj "." #min))
 384 #else
 385 #define G_UNAVAILABLE(maj,min) G_DEPRECATED
 386 #endif
 387
 388 #ifndef _GLIB_EXTERN
 389 #define _GLIB_EXTERN extern
 390 #endif
 391
 392 /* These macros are used to mark deprecated functions in GLib headers,
 393  * and thus have to be exposed in installed headers. But please
 394  * do *not* use them in other projects. Instead, use G_DEPRECATED
 395  * or define your own wrappers around it.
 396  */
 397
 398 #ifdef GLIB_DISABLE_DEPRECATION_WARNINGS
 399 #define GLIB_DEPRECATED _GLIB_EXTERN
 400 #define GLIB_DEPRECATED_FOR(f) _GLIB_EXTERN
 401 #define GLIB_UNAVAILABLE(maj,min) _GLIB_EXTERN
 402 #else
 403 #define GLIB_DEPRECATED G_DEPRECATED _GLIB_EXTERN
 404 #define GLIB_DEPRECATED_FOR(f) G_DEPRECATED_FOR(f) _GLIB_EXTERN
 405 #define GLIB_UNAVAILABLE(maj,min) G_UNAVAILABLE(maj,min) _GLIB_EXTERN
 406 #endif
 407
 408 #ifdef __GNUC__
 409
 410 /* these macros are private */
 411 #define _GLIB_AUTOPTR_FUNC_NAME(TypeName) glib_autoptr_cleanup_##TypeName
 412 #define _GLIB_AUTOPTR_TYPENAME(TypeName)  TypeName##_autoptr
 413 #define _GLIB_AUTO_FUNC_NAME(TypeName)    glib_auto_cleanup_##TypeName
 414 #define _GLIB_CLEANUP(func)               __attribute__((cleanup(func)))
 415 #define _GLIB_DEFINE_AUTOPTR_CHAINUP(ModuleObjName, ParentName) \
 416   typedef ModuleObjName *_GLIB_AUTOPTR_TYPENAME(ModuleObjName);                                          \
 417   static inline void _GLIB_AUTOPTR_FUNC_NAME(ModuleObjName) (ModuleObjName **_ptr) {                     \
 418     _GLIB_AUTOPTR_FUNC_NAME(ParentName) ((ParentName **) _ptr); }                                        \
 419
 420
 421 /* these macros are API */
 422 #define G_DEFINE_AUTOPTR_CLEANUP_FUNC(TypeName, func) \
 423   typedef TypeName *_GLIB_AUTOPTR_TYPENAME(TypeName);                                                           \
 424   G_GNUC_BEGIN_IGNORE_DEPRECATIONS                                                                              \
 425   static inline void _GLIB_AUTOPTR_FUNC_NAME(TypeName) (TypeName **_ptr) { if (*_ptr) (func) (*_ptr); }         \
 426   G_GNUC_END_IGNORE_DEPRECATIONS
 427 #define G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(TypeName, func) \
 428   G_GNUC_BEGIN_IGNORE_DEPRECATIONS                                                                              \
 429   static inline void _GLIB_AUTO_FUNC_NAME(TypeName) (TypeName *_ptr) { (func) (_ptr); }                         \
 430   G_GNUC_END_IGNORE_DEPRECATIONS
 431 #define G_DEFINE_AUTO_CLEANUP_FREE_FUNC(TypeName, func, none) \
 432   G_GNUC_BEGIN_IGNORE_DEPRECATIONS                                                                              \
 433   static inline void _GLIB_AUTO_FUNC_NAME(TypeName) (TypeName *_ptr) { if (*_ptr != none) (func) (*_ptr); }     \
 434   G_GNUC_END_IGNORE_DEPRECATIONS
 435 #define g_autoptr(TypeName) _GLIB_CLEANUP(_GLIB_AUTOPTR_FUNC_NAME(TypeName)) _GLIB_AUTOPTR_TYPENAME(TypeName)
 436 #define g_auto(TypeName) _GLIB_CLEANUP(_GLIB_AUTO_FUNC_NAME(TypeName)) TypeName
 437 #define g_autofree _GLIB_CLEANUP(g_autoptr_cleanup_generic_gfree)
 438
 439 #else /* not GNU C */
 440 /* this (dummy) macro is private */
 441 #define _GLIB_DEFINE_AUTOPTR_CHAINUP(ModuleObjName, ParentName)
 442
 443 /* these (dummy) macros are API */
 444 #define G_DEFINE_AUTOPTR_CLEANUP_FUNC(TypeName, func)
 445 #define G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(TypeName, func)
 446 #define G_DEFINE_AUTO_CLEANUP_FREE_FUNC(TypeName, func, none)
 447
 448 /* no declaration of g_auto() or g_autoptr() here */
 449 #endif
 450
 451 #endif /* __G_MACROS_H__ */