include/sys/feature_tests.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2013, 2014 Garrett D'Amore <garrett@damore.org>
  24  * Copyright 2016 Joyent, Inc.
  25  *
  26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  27  * Use is subject to license terms.
  28  */
  29
  30 #ifndef _SYS_FEATURE_TESTS_H
  31 #define _SYS_FEATURE_TESTS_H
  32
  33 #include <sys/ccompile.h>
  34 #include <sys/isa_defs.h>
  35
  36 #ifdef  __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 /*
  41  * Values of _POSIX_C_SOURCE
  42  *
  43  *              undefined   not a POSIX compilation
  44  *              1           POSIX.1-1990 compilation
  45  *              2           POSIX.2-1992 compilation
  46  *              199309L     POSIX.1b-1993 compilation (Real Time)
  47  *              199506L     POSIX.1c-1995 compilation (POSIX Threads)
  48  *              200112L     POSIX.1-2001 compilation (Austin Group Revision)
  49  *              200809L     POSIX.1-2008 compilation
  50  */
  51 #if defined(_POSIX_SOURCE) && !defined(_POSIX_C_SOURCE)
  52 #define _POSIX_C_SOURCE 1
  53 #endif
  54
  55 /*
  56  * The feature test macros __XOPEN_OR_POSIX, _STRICT_STDC, _STRICT_SYMBOLS,
  57  * and _STDC_C99 are Sun implementation specific macros created in order to
  58  * compress common standards specified feature test macros for easier reading.
  59  * These macros should not be used by the application developer as
  60  * unexpected results may occur. Instead, the user should reference
  61  * standards(5) for correct usage of the standards feature test macros.
  62  *
  63  * __XOPEN_OR_POSIX     Used in cases where a symbol is defined by both
  64  *                      X/Open or POSIX or in the negative, when neither
  65  *                      X/Open or POSIX defines a symbol.
  66  *
  67  * _STRICT_STDC         __STDC__ is specified by the C Standards and defined
  68  *                      by the compiler. For Sun compilers the value of
  69  *                      __STDC__ is either 1, 0, or not defined based on the
  70  *                      compilation mode (see cc(1)). When the value of
  71  *                      __STDC__ is 1 and in the absence of any other feature
  72  *                      test macros, the namespace available to the application
  73  *                      is limited to only those symbols defined by the C
  74  *                      Standard. _STRICT_STDC provides a more readable means
  75  *                      of identifying symbols defined by the standard, or in
  76  *                      the negative, symbols that are extensions to the C
  77  *                      Standard. See additional comments for GNU C differences.
  78  *
  79  * _STDC_C99            __STDC_VERSION__ is specified by the C standards and
  80  *                      defined by the compiler and indicates the version of
  81  *                      the C standard. A value of 199901L indicates a
  82  *                      compiler that complies with ISO/IEC 9899:1999, other-
  83  *                      wise known as the C99 standard.
  84  *
  85  * _STDC_C11            Like _STDC_C99 except that the value of __STDC_VERSION__
  86  *                      is 201112L indicating a compiler that compiles with
  87  *                      ISO/IEXC 9899:2011, otherwise known as the C11 standard.
  88  *
  89  * _STRICT_SYMBOLS      Used in cases where symbol visibility is restricted
  90  *                      by the standards, and the user has not explicitly
  91  *                      relaxed the strictness via __EXTENSIONS__.
  92  */
  93
  94 #if defined(_XOPEN_SOURCE) || defined(_POSIX_C_SOURCE)
  95 #define __XOPEN_OR_POSIX
  96 #endif
  97
  98 /*
  99  * ISO/IEC 9899:1990 and it's revisions, ISO/IEC 9899:1999 and ISO/IEC
 100  * 99899:2011 specify the following predefined macro name:
 101  *
 102  * __STDC__     The integer constant 1, intended to indicate a conforming
 103  *              implementation.
 104  *
 105  * Furthermore, a strictly conforming program shall use only those features
 106  * of the language and library specified in these standards. A conforming
 107  * implementation shall accept any strictly conforming program.
 108  *
 109  * Based on these requirements, Sun's C compiler defines __STDC__ to 1 for
 110  * strictly conforming environments and __STDC__ to 0 for environments that
 111  * use ANSI C semantics but allow extensions to the C standard. For non-ANSI
 112  * C semantics, Sun's C compiler does not define __STDC__.
 113  *
 114  * The GNU C project interpretation is that __STDC__ should always be defined
 115  * to 1 for compilation modes that accept ANSI C syntax regardless of whether
 116  * or not extensions to the C standard are used. Violations of conforming
 117  * behavior are conditionally flagged as warnings via the use of the
 118  * -pedantic option. In addition to defining __STDC__ to 1, the GNU C
 119  * compiler also defines __STRICT_ANSI__ as a means of specifying strictly
 120  * conforming environments using the -ansi or -std=<standard> options.
 121  *
 122  * In the absence of any other compiler options, Sun and GNU set the value
 123  * of __STDC__ as follows when using the following options:
 124  *
 125  *                              Value of __STDC__  __STRICT_ANSI__
 126  *
 127  * cc -Xa (default)                     0             undefined
 128  * cc -Xt (transitional)                0             undefined
 129  * cc -Xc (strictly conforming)         1             undefined
 130  * cc -Xs (K&R C)                   undefined         undefined
 131  *
 132  * gcc (default)                        1             undefined
 133  * gcc -ansi, -std={c89, c99,...)       1              defined
 134  * gcc -traditional (K&R)           undefined         undefined
 135  *
 136  * The default compilation modes for Sun C compilers versus GNU C compilers
 137  * results in a differing value for __STDC__ which results in a more
 138  * restricted namespace when using Sun compilers. To allow both GNU and Sun
 139  * interpretations to peacefully co-exist, we use the following Sun
 140  * implementation _STRICT_STDC_ macro:
 141  */
 142
 143 #if (__STDC__ - 0 == 1 && !defined(__GNUC__)) || \
 144         (defined(__GNUC__) && defined(__STRICT_ANSI__)) || \
 145         defined(_ASM)
 146 #define _STRICT_STDC
 147 #else
 148 #undef  _STRICT_STDC
 149 #endif
 150
 151 /*
 152  * Compiler complies with ISO/IEC 9899:1999 or ISO/IEC 9989:2011
 153  */
 154
 155 #if __STDC_VERSION__ - 0 >= 201112L
 156 #define _STDC_C11
 157 #endif
 158
 159 #if __STDC_VERSION__ - 0 >= 199901L
 160 #define _STDC_C99
 161 #endif
 162
 163 /*
 164  * Use strict symbol visibility.
 165  */
 166 #if (defined(_STRICT_STDC) || defined(__XOPEN_OR_POSIX)) && \
 167         !defined(__EXTENSIONS__)
 168 #define _STRICT_SYMBOLS
 169 #endif
 170
 171 /*
 172  * Large file interfaces:
 173  *
 174  *      _LARGEFILE_SOURCE
 175  *              1               large file-related additions to POSIX
 176  *                              interfaces requested (fseeko, etc.)
 177  *      _LARGEFILE64_SOURCE
 178  *              1               transitional large-file-related interfaces
 179  *                              requested (seek64, stat64, etc.)
 180  *
 181  * The corresponding announcement macros are respectively:
 182  *      _LFS_LARGEFILE
 183  *      _LFS64_LARGEFILE
 184  * (These are set in <unistd.h>.)
 185  *
 186  * Requesting _LARGEFILE64_SOURCE implies requesting _LARGEFILE_SOURCE as
 187  * well.
 188  *
 189  * The large file interfaces are made visible regardless of the initial values
 190  * of the feature test macros under certain circumstances:
 191  *    - If no explicit standards-conforming environment is requested (neither
 192  *      of _POSIX_SOURCE nor _XOPEN_SOURCE is defined and the value of
 193  *      __STDC__ does not imply standards conformance).
 194  *    - Extended system interfaces are explicitly requested (__EXTENSIONS__
 195  *      is defined).
 196  *    - Access to in-kernel interfaces is requested (_KERNEL or _KMEMUSER is
 197  *      defined).  (Note that this dependency is an artifact of the current
 198  *      kernel implementation and may change in future releases.)
 199  */
 200 #if     (!defined(_STRICT_STDC) && !defined(__XOPEN_OR_POSIX)) || \
 201                 defined(_KERNEL) || defined(_KMEMUSER) || \
 202                 defined(__EXTENSIONS__)
 203 #undef  _LARGEFILE64_SOURCE
 204 #define _LARGEFILE64_SOURCE     1
 205 #endif
 206 #if     _LARGEFILE64_SOURCE - 0 == 1
 207 #undef  _LARGEFILE_SOURCE
 208 #define _LARGEFILE_SOURCE       1
 209 #endif
 210
 211 /*
 212  * Large file compilation environment control:
 213  *
 214  * The setting of _FILE_OFFSET_BITS controls the size of various file-related
 215  * types and governs the mapping between file-related source function symbol
 216  * names and the corresponding binary entry points.
 217  *
 218  * In the 32-bit environment, the default value is 32; if not set, set it to
 219  * the default here, to simplify tests in other headers.
 220  *
 221  * In the 64-bit compilation environment, the only value allowed is 64.
 222  */
 223 #if defined(_LP64)
 224 #ifndef _FILE_OFFSET_BITS
 225 #define _FILE_OFFSET_BITS       64
 226 #endif
 227 #if     _FILE_OFFSET_BITS - 0 != 64
 228 #error  "invalid _FILE_OFFSET_BITS value specified"
 229 #endif
 230 #else   /* _LP64 */
 231 #ifndef _FILE_OFFSET_BITS
 232 #define _FILE_OFFSET_BITS       32
 233 #endif
 234 #if     _FILE_OFFSET_BITS - 0 != 32 && _FILE_OFFSET_BITS - 0 != 64
 235 #error  "invalid _FILE_OFFSET_BITS value specified"
 236 #endif
 237 #endif  /* _LP64 */
 238
 239 /*
 240  * Use of _XOPEN_SOURCE
 241  *
 242  * The following X/Open specifications are supported:
 243  *
 244  * X/Open Portability Guide, Issue 3 (XPG3)
 245  * X/Open CAE Specification, Issue 4 (XPG4)
 246  * X/Open CAE Specification, Issue 4, Version 2 (XPG4v2)
 247  * X/Open CAE Specification, Issue 5 (XPG5)
 248  * Open Group Technical Standard, Issue 6 (XPG6), also referred to as
 249  *    IEEE Std. 1003.1-2001 and ISO/IEC 9945:2002.
 250  * Open Group Technical Standard, Issue 7 (XPG7), also referred to as
 251  *    IEEE Std. 1003.1-2008 and ISO/IEC 9945:2009.
 252  *
 253  * XPG4v2 is also referred to as UNIX 95 (SUS or SUSv1).
 254  * XPG5 is also referred to as UNIX 98 or the Single Unix Specification,
 255  *     Version 2 (SUSv2)
 256  * XPG6 is the result of a merge of the X/Open and POSIX specifications
 257  *     and as such is also referred to as IEEE Std. 1003.1-2001 in
 258  *     addition to UNIX 03 and SUSv3.
 259  * XPG7 is also referred to as UNIX 08 and SUSv4.
 260  *
 261  * When writing a conforming X/Open application, as per the specification
 262  * requirements, the appropriate feature test macros must be defined at
 263  * compile time. These are as follows. For more info, see standards(5).
 264  *
 265  * Feature Test Macro                                Specification
 266  * ------------------------------------------------  -------------
 267  * _XOPEN_SOURCE                                         XPG3
 268  * _XOPEN_SOURCE && _XOPEN_VERSION = 4                   XPG4
 269  * _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED = 1           XPG4v2
 270  * _XOPEN_SOURCE = 500                                   XPG5
 271  * _XOPEN_SOURCE = 600  (or POSIX_C_SOURCE=200112L)      XPG6
 272  * _XOPEN_SOURCE = 700  (or POSIX_C_SOURCE=200809L)      XPG7
 273  *
 274  * In order to simplify the guards within the headers, the following
 275  * implementation private test macros have been created. Applications
 276  * must NOT use these private test macros as unexpected results will
 277  * occur.
 278  *
 279  * Note that in general, the use of these private macros is cumulative.
 280  * For example, the use of _XPG3 with no other restrictions on the X/Open
 281  * namespace will make the symbols visible for XPG3 through XPG6
 282  * compilation environments. The use of _XPG4_2 with no other X/Open
 283  * namespace restrictions indicates that the symbols were introduced in
 284  * XPG4v2 and are therefore visible for XPG4v2 through XPG6 compilation
 285  * environments, but not for XPG3 or XPG4 compilation environments.
 286  *
 287  * _XPG3    X/Open Portability Guide, Issue 3 (XPG3)
 288  * _XPG4    X/Open CAE Specification, Issue 4 (XPG4)
 289  * _XPG4_2  X/Open CAE Specification, Issue 4, Version 2 (XPG4v2/UNIX 95/SUS)
 290  * _XPG5    X/Open CAE Specification, Issue 5 (XPG5/UNIX 98/SUSv2)
 291  * _XPG6    Open Group Technical Standard, Issue 6 (XPG6/UNIX 03/SUSv3)
 292  * _XPG7    Open Group Technical Standard, Issue 7 (XPG7/UNIX 08/SUSv4)
 293  */
 294
 295 /* X/Open Portability Guide, Issue 3 */
 296 #if defined(_XOPEN_SOURCE) && (_XOPEN_SOURCE - 0 < 500) && \
 297         (_XOPEN_VERSION - 0 < 4) && !defined(_XOPEN_SOURCE_EXTENDED)
 298 #define _XPG3
 299 /* X/Open CAE Specification, Issue 4 */
 300 #elif   (defined(_XOPEN_SOURCE) && _XOPEN_VERSION - 0 == 4)
 301 #define _XPG4
 302 #define _XPG3
 303 /* X/Open CAE Specification, Issue 4, Version 2 */
 304 #elif (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE_EXTENDED - 0 == 1)
 305 #define _XPG4_2
 306 #define _XPG4
 307 #define _XPG3
 308 /* X/Open CAE Specification, Issue 5 */
 309 #elif   (_XOPEN_SOURCE - 0 == 500)
 310 #define _XPG5
 311 #define _XPG4_2
 312 #define _XPG4
 313 #define _XPG3
 314 #undef  _POSIX_C_SOURCE
 315 #define _POSIX_C_SOURCE                 199506L
 316 /* Open Group Technical Standard , Issue 6 */
 317 #elif   (_XOPEN_SOURCE - 0 == 600) || (_POSIX_C_SOURCE - 0 == 200112L)
 318 #define _XPG6
 319 #define _XPG5
 320 #define _XPG4_2
 321 #define _XPG4
 322 #define _XPG3
 323 #undef  _POSIX_C_SOURCE
 324 #define _POSIX_C_SOURCE                 200112L
 325 #undef  _XOPEN_SOURCE
 326 #define _XOPEN_SOURCE                   600
 327
 328 /* Open Group Technical Standard, Issue 7 */
 329 #elif   (_XOPEN_SOURCE - 0 == 700) || (_POSIX_C_SOURCE - 0 == 200809L)
 330 #define _XPG7
 331 #define _XPG6
 332 #define _XPG5
 333 #define _XPG4_2
 334 #define _XPG4
 335 #define _XPG3
 336 #undef  _POSIX_C_SOURCE
 337 #define _POSIX_C_SOURCE                 200809L
 338 #undef  _XOPEN_SOURCE
 339 #define _XOPEN_SOURCE                   700
 340 #endif
 341
 342 /*
 343  * _XOPEN_VERSION is defined by the X/Open specifications and is not
 344  * normally defined by the application, except in the case of an XPG4
 345  * application.  On the implementation side, _XOPEN_VERSION defined with
 346  * the value of 3 indicates an XPG3 application. _XOPEN_VERSION defined
 347  * with the value of 4 indicates an XPG4 or XPG4v2 (UNIX 95) application.
 348  * _XOPEN_VERSION  defined with a value of 500 indicates an XPG5 (UNIX 98)
 349  * application and with a value of 600 indicates an XPG6 (UNIX 03)
 350  * application and with a value of 700 indicates an XPG7 (UNIX 08).
 351  * The appropriate version is determined by the use of the
 352  * feature test macros described earlier.  The value of _XOPEN_VERSION
 353  * defaults to 3 otherwise indicating support for XPG3 applications.
 354  */
 355 #ifndef _XOPEN_VERSION
 356 #if     defined(_XPG7)
 357 #define _XOPEN_VERSION 700
 358 #elif   defined(_XPG6)
 359 #define _XOPEN_VERSION 600
 360 #elif defined(_XPG5)
 361 #define _XOPEN_VERSION 500
 362 #elif   defined(_XPG4_2)
 363 #define _XOPEN_VERSION  4
 364 #else
 365 #define _XOPEN_VERSION  3
 366 #endif
 367 #endif
 368
 369 /*
 370  * ANSI C and ISO 9899:1990 say the type long long doesn't exist in strictly
 371  * conforming environments.  ISO 9899:1999 says it does.
 372  *
 373  * The presence of _LONGLONG_TYPE says "long long exists" which is therefore
 374  * defined in all but strictly conforming environments that disallow it.
 375  */
 376 #if !defined(_STDC_C99) && defined(_STRICT_STDC) && !defined(__GNUC__)
 377 /*
 378  * Resist attempts to force the definition of long long in this case.
 379  */
 380 #if defined(_LONGLONG_TYPE)
 381 #error  "No long long in strictly conforming ANSI C & 1990 ISO C environments"
 382 #endif
 383 #else
 384 #if !defined(_LONGLONG_TYPE)
 385 #define _LONGLONG_TYPE
 386 #endif
 387 #endif
 388
 389 /*
 390  * It is invalid to compile an XPG3, XPG4, XPG4v2, or XPG5 application
 391  * using c99.  The same is true for POSIX.1-1990, POSIX.2-1992, POSIX.1b,
 392  * and POSIX.1c applications. Likewise, it is invalid to compile an XPG6
 393  * or a POSIX.1-2001 application with anything other than a c99 or later
 394  * compiler.  Therefore, we force an error in both cases.
 395  */
 396 #if defined(_STDC_C99) && (defined(__XOPEN_OR_POSIX) && !defined(_XPG6))
 397 #error "Compiler or options invalid for pre-UNIX 03 X/Open applications \
 398         and pre-2001 POSIX applications"
 399 #elif !defined(_STDC_C99) && \
 400         (defined(__XOPEN_OR_POSIX) && defined(_XPG6))
 401 #error "Compiler or options invalid; UNIX 03 and POSIX.1-2001 applications \
 402         require the use of c99"
 403 #endif
 404
 405 /*
 406  * The following macro defines a value for the ISO C99 restrict
 407  * keyword so that _RESTRICT_KYWD resolves to "restrict" if
 408  * an ISO C99 compiler is used, "__restrict" for c++ and "" (null string)
 409  * if any other compiler is used. This allows for the use of single
 410  * prototype declarations regardless of compiler version.
 411  */
 412 #if (defined(__STDC__) && defined(_STDC_C99))
 413 #ifdef __cplusplus
 414 #define _RESTRICT_KYWD  __restrict
 415 #else
 416 /*
 417  * NOTE: The whitespace between the '#' and 'define' is significant.
 418  * It foils gcc's fixincludes from defining a redundant 'restrict'.
 419  */
 420 /* CSTYLED */
 421 # define        _RESTRICT_KYWD  restrict
 422 #endif
 423 #else
 424 #define _RESTRICT_KYWD
 425 #endif
 426
 427 /*
 428  * The following macro defines a value for the ISO C11 _Noreturn
 429  * keyword so that _NORETURN_KYWD resolves to "_Noreturn" if
 430  * an ISO C11 compiler is used and "" (null string) if any other
 431  * compiler is used. This allows for the use of single prototype
 432  * declarations regardless of compiler version.
 433  */
 434 #if (defined(__STDC__) && defined(_STDC_C11)) && !defined(__cplusplus)
 435 #define _NORETURN_KYWD  _Noreturn
 436 #else
 437 #define _NORETURN_KYWD
 438 #endif
 439
 440
 441 /*
 442  * The following macro indicates header support for the ANSI C++
 443  * standard.  The ISO/IEC designation for this is ISO/IEC FDIS 14882.
 444  */
 445 #define _ISO_CPP_14882_1998
 446
 447 /*
 448  * The following macro indicates header support for the C99 standard,
 449  * ISO/IEC 9899:1999, Programming Languages - C.
 450  */
 451 #define _ISO_C_9899_1999
 452
 453 /*
 454  * The following macro indicates header support for the C99 standard,
 455  * ISO/IEC 9899:2011, Programming Languages - C.
 456  */
 457 #define _ISO_C_9899_2011
 458
 459 /*
 460  * The following macro indicates header support for DTrace. The value is an
 461  * integer that corresponds to the major version number for DTrace.
 462  */
 463 #define _DTRACE_VERSION 1
 464
 465 /*
 466  * The following macro indicates that we are on illumos, and serves to
 467  * distinguish us from other SunOS derived systems.
 468  */
 469 #define _ILLUMOS        1
 470
 471 #ifdef  __cplusplus
 472 }
 473 #endif
 474
 475 #endif  /* _SYS_FEATURE_TESTS_H */