include/vlc_common.h

   1 /*****************************************************************************
   2  * vlc_common.h: common definitions
   3  * Collection of useful common types and macros definitions
   4  *****************************************************************************
   5  * Copyright (C) 1998-2011 VLC authors and VideoLAN
   6  *
   7  * Authors: Samuel Hocevar <sam@via.ecp.fr>
   8  *          Vincent Seguin <seguin@via.ecp.fr>
   9  *          Gildas Bazin <gbazin@videolan.org>
  10  *          Rémi Denis-Courmont
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU Lesser General Public License as published by
  14  * the Free Software Foundation; either version 2.1 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program 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 Lesser General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public License
  23  * along with this program; if not, write to the Free Software Foundation,
  24  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 #ifndef VLC_COMMON_H
  28 # define VLC_COMMON_H 1
  29
  30 /**
  31  * \defgroup vlc VLC plug-in programming interface
  32  * \file
  33  * \ingroup vlc
  34  * This file is a collection of common definitions and types
  35  */
  36
  37 /*****************************************************************************
  38  * Required vlc headers
  39  *****************************************************************************/
  40 #include "vlc_config.h"
  41
  42 /*****************************************************************************
  43  * Required system headers
  44  *****************************************************************************/
  45 #include <stdlib.h>
  46 #include <stdarg.h>
  47
  48 #include <string.h>
  49 #include <stdio.h>
  50 #include <inttypes.h>
  51 #include <stddef.h>
  52
  53 #ifndef __cplusplus
  54 # include <stdbool.h>
  55 #endif
  56
  57 /**
  58  * \defgroup cext C programming language extensions
  59  * \ingroup vlc
  60  *
  61  * This section defines a number of macros and inline functions extending the
  62  * C language. Most extensions are implemented by GCC and LLVM/Clang, and have
  63  * unoptimized fallbacks for other C11/C++11 conforming compilers.
  64  * @{
  65  */
  66 #ifdef __GNUC__
  67 # define VLC_GCC_VERSION(maj,min) \
  68     ((__GNUC__ > (maj)) || (__GNUC__ == (maj) && __GNUC_MINOR__ >= (min)))
  69 #else
  70 /** GCC version check */
  71 # define VLC_GCC_VERSION(maj,min) (0)
  72 #endif
  73
  74 /* Try to fix format strings for all versions of mingw and mingw64 */
  75 #if defined( _WIN32 ) && defined( __USE_MINGW_ANSI_STDIO )
  76  #undef PRId64
  77  #define PRId64 "lld"
  78  #undef PRIi64
  79  #define PRIi64 "lli"
  80  #undef PRIu64
  81  #define PRIu64 "llu"
  82  #undef PRIo64
  83  #define PRIo64 "llo"
  84  #undef PRIx64
  85  #define PRIx64 "llx"
  86  #define snprintf __mingw_snprintf
  87  #define vsnprintf __mingw_vsnprintf
  88  #define swprintf _snwprintf
  89 #endif
  90
  91 /* Function attributes for compiler warnings */
  92 #ifdef __GNUC__
  93 # define VLC_DEPRECATED __attribute__((deprecated))
  94 # if VLC_GCC_VERSION(6,0)
  95 #  define VLC_DEPRECATED_ENUM __attribute__((deprecated))
  96 # else
  97 #  define VLC_DEPRECATED_ENUM
  98 # endif
  99
 100 # if defined( _WIN32 ) && !defined( __clang__ )
 101 #  define VLC_FORMAT(x,y) __attribute__ ((format(gnu_printf,x,y)))
 102 # else
 103 #  define VLC_FORMAT(x,y) __attribute__ ((format(printf,x,y)))
 104 # endif
 105 # define VLC_FORMAT_ARG(x) __attribute__ ((format_arg(x)))
 106 # define VLC_MALLOC __attribute__ ((malloc))
 107 # define VLC_USED __attribute__ ((warn_unused_result))
 108
 109 #else
 110 /**
 111  * Deprecated functions or compound members annotation
 112  *
 113  * Use this macro in front of a function declaration or compound member
 114  * within a compound type declaration.
 115  * The compiler may emit a warning every time the function or member is used.
 116  *
 117  * Use \ref VLC_DEPRECATED_ENUM instead for enumeration members.
 118  */
 119 # define VLC_DEPRECATED
 120
 121 /**
 122  * Deprecated enum member annotation
 123  *
 124  * Use this macro after an enumerated type member declaration.
 125  * The compiler may emit a warning every time the enumeration member is used.
 126  *
 127  * See also \ref VLC_DEPRECATED.
 128  */
 129 # define VLC_DEPRECATED_ENUM
 130
 131 /**
 132  * String format function annotation
 133  *
 134  * Use this macro after a function prototype/declaration if the function
 135  * expects a standard C format string. This helps compiler diagnostics.
 136  *
 137  * @param x the position (starting from 1) of the format string argument
 138  * @param y the first position (also starting from 1) of the variable arguments
 139  *          following the format string (usually but not always \p x+1).
 140  */
 141 # define VLC_FORMAT(x,y)
 142
 143 /**
 144  * Format string translation function annotation
 145  *
 146  * Use this macro after a function prototype/declaration if the function
 147  * expects a format string as input and returns another format string as output
 148  * to another function.
 149  *
 150  * This is primarily intended for localization functions such as gettext().
 151  */
 152 # define VLC_FORMAT_ARG(x)
 153
 154 /**
 155  * Heap allocated result function annotation
 156  *
 157  * Use this macro to annotate a function that returns a pointer to memory that
 158  * cannot alias any other valid pointer.
 159  *
 160  * This is primarily used for functions that return a pointer to heap-allocated
 161  * memory, but it can be used for other applicable purposes.
 162  *
 163  * \warning Do not use this annotation if the returned pointer can in any way
 164  * alias a valid pointer at the time the function exits. This could lead to
 165  * very weird memory corruption bugs.
 166  */
 167 # define VLC_MALLOC
 168
 169 /**
 170  * Used result function annotation
 171  *
 172  * Use this macro to annotate a function whose result must be used.
 173  *
 174  * There are several cases where this is useful:
 175  * - If a function has no side effects (or no useful side effects), such that
 176  *   the only useful purpose of calling said function is to obtain its
 177  *   return value.
 178  * - If ignoring the function return value would lead to a resource leak
 179  *   (including but not limited to a memory leak).
 180  * - If a function cannot be used correctly without checking its return value.
 181  *   For instance, if the function can fail at any time.
 182  *
 183  * The compiler may warn if the return value of a function call is ignored.
 184  */
 185 # define VLC_USED
 186 #endif
 187
 188 #if defined (__ELF__) || defined (__MACH__)
 189 # define VLC_WEAK __attribute__((weak))
 190 #else
 191 /**
 192  * Weak symbol annotation
 193  *
 194  * Use this macro before an external identifier \b definition to mark it as a
 195  * weak symbol. A weak symbol can be overriden by another symbol of the same
 196  * name at the link time.
 197  */
 198 # define VLC_WEAK
 199 #endif
 200
 201 /* Branch prediction */
 202 #if defined (__GNUC__) || defined (__clang__)
 203 # define likely(p)     __builtin_expect(!!(p), 1)
 204 # define unlikely(p)   __builtin_expect(!!(p), 0)
 205 # define unreachable() __builtin_unreachable()
 206 #elif defined(_MSC_VER)
 207 # define likely(p)     (!!(p))
 208 # define unlikely(p)   (!!(p))
 209 # define unreachable() (__assume(0))
 210 #else
 211 /**
 212  * Predicted true condition
 213  *
 214  * This macro indicates that the condition is expected most often true.
 215  * The compiler may optimize the code assuming that this condition is usually
 216  * met.
 217  */
 218 # define likely(p)     (!!(p))
 219
 220 /**
 221  * Predicted false condition
 222  *
 223  * This macro indicates that the condition is expected most often false.
 224  * The compiler may optimize the code assuming that this condition is rarely
 225  * met.
 226  */
 227 # define unlikely(p)   (!!(p))
 228
 229 /**
 230  * Impossible branch
 231  *
 232  * This macro indicates that the branch cannot be reached at run-time, and
 233  * represents undefined behaviour.
 234  * The compiler may optimize the code assuming that the call flow will never
 235  * logically reach the point where this macro is expanded.
 236  *
 237  * See also \ref vlc_assert_unreachable.
 238  */
 239 # define unreachable() ((void)0)
 240 #endif
 241
 242 /**
 243  * Impossible branch assertion
 244  *
 245  * This macro asserts that the branch cannot be reached at run-time.
 246  *
 247  * If the branch is reached in a debug build, it will trigger an assertion
 248  * failure and abnormal program termination.
 249  *
 250  * If the branch is reached in a non-debug build, this macro is equivalent to
 251  * \ref unreachable and the behaviour is undefined.
 252  */
 253 #define vlc_assert_unreachable() (vlc_assert(!"unreachable"), unreachable())
 254
 255 /**
 256  * Run-time assertion
 257  *
 258  * This macro performs a run-time assertion if C assertions are enabled
 259  * and the following preprocessor symbol is defined:
 260  * @verbatim __LIBVLC__ @endverbatim
 261  * That restriction ensures that assertions in public header files are not
 262  * unwittingly <i>leaked</i> to externally-compiled plug-ins
 263  * including those header files.
 264  *
 265  * Within the LibVLC code base, this is exactly the same as assert(), which can
 266  * and probably should be used directly instead.
 267  */
 268 #ifdef __LIBVLC__
 269 # define vlc_assert(pred) assert(pred)
 270 #else
 271 # define vlc_assert(pred) ((void)0)
 272 #endif
 273
 274 /* Linkage */
 275 #ifdef __cplusplus
 276 # define VLC_EXTERN extern "C"
 277 #else
 278 # define VLC_EXTERN
 279 #endif
 280
 281 #if defined (_WIN32) && defined (DLL_EXPORT)
 282 # define VLC_EXPORT __declspec(dllexport)
 283 #elif defined (__GNUC__)
 284 # define VLC_EXPORT __attribute__((visibility("default")))
 285 #else
 286 # define VLC_EXPORT
 287 #endif
 288
 289 /**
 290  * Exported API call annotation
 291  *
 292  * This macro is placed before a function declaration to indicate that the
 293  * function is an API call of the LibVLC plugin API.
 294  */
 295 #define VLC_API VLC_EXTERN VLC_EXPORT
 296
 297 /** @} */
 298
 299 /*****************************************************************************
 300  * Basic types definitions
 301  *****************************************************************************/
 302 /**
 303  * The vlc_fourcc_t type.
 304  *
 305  * See http://www.webartz.com/fourcc/ for a very detailed list.
 306  */
 307 typedef uint32_t vlc_fourcc_t;
 308
 309 #ifdef WORDS_BIGENDIAN
 310 #   define VLC_FOURCC( a, b, c, d ) \
 311         ( ((uint32_t)d) | ( ((uint32_t)c) << 8 ) \
 312            | ( ((uint32_t)b) << 16 ) | ( ((uint32_t)a) << 24 ) )
 313 #   define VLC_TWOCC( a, b ) \
 314         ( (uint16_t)(b) | ( (uint16_t)(a) << 8 ) )
 315
 316 #else
 317 #   define VLC_FOURCC( a, b, c, d ) \
 318         ( ((uint32_t)a) | ( ((uint32_t)b) << 8 ) \
 319            | ( ((uint32_t)c) << 16 ) | ( ((uint32_t)d) << 24 ) )
 320 #   define VLC_TWOCC( a, b ) \
 321         ( (uint16_t)(a) | ( (uint16_t)(b) << 8 ) )
 322
 323 #endif
 324
 325 /**
 326  * Translate a vlc_fourcc into its string representation. This function
 327  * assumes there is enough room in psz_fourcc to store 4 characters in.
 328  *
 329  * \param fcc a vlc_fourcc_t
 330  * \param psz_fourcc string to store string representation of vlc_fourcc in
 331  */
 332 static inline void vlc_fourcc_to_char( vlc_fourcc_t fcc, char *psz_fourcc )
 333 {
 334     memcpy( psz_fourcc, &fcc, 4 );
 335 }
 336
 337 /*****************************************************************************
 338  * Classes declaration
 339  *****************************************************************************/
 340
 341 /* Internal types */
 342 typedef struct vlc_object_t vlc_object_t;
 343 typedef struct libvlc_int_t libvlc_int_t;
 344 typedef struct date_t date_t;
 345
 346 /* Playlist */
 347
 348 typedef struct services_discovery_t services_discovery_t;
 349 typedef struct vlc_renderer_discovery_t vlc_renderer_discovery_t;
 350 typedef struct vlc_renderer_item_t vlc_renderer_item_t;
 351
 352 /* Modules */
 353 typedef struct module_t module_t;
 354 typedef struct module_config_t module_config_t;
 355
 356 typedef struct config_category_t config_category_t;
 357
 358 /* Input */
 359 typedef struct input_item_t input_item_t;
 360 typedef struct input_item_node_t input_item_node_t;
 361 typedef struct input_source_t input_source_t;
 362 typedef struct stream_t     stream_t;
 363 typedef struct stream_t demux_t;
 364 typedef struct es_out_t     es_out_t;
 365 typedef struct es_out_id_t  es_out_id_t;
 366 typedef struct seekpoint_t seekpoint_t;
 367 typedef struct info_t info_t;
 368 typedef struct info_category_t info_category_t;
 369 typedef struct input_attachment_t input_attachment_t;
 370
 371 /* Format */
 372 typedef struct audio_format_t audio_format_t;
 373 typedef struct video_format_t video_format_t;
 374 typedef struct subs_format_t subs_format_t;
 375 typedef struct es_format_t es_format_t;
 376 typedef struct video_palette_t video_palette_t;
 377 typedef struct vlc_es_id_t vlc_es_id_t;
 378
 379 /* Audio */
 380 typedef struct audio_output audio_output_t;
 381 typedef audio_format_t audio_sample_format_t;
 382
 383 /* Video */
 384 typedef struct vout_thread_t vout_thread_t;
 385 typedef struct vlc_viewpoint_t vlc_viewpoint_t;
 386
 387 typedef video_format_t video_frame_format_t;
 388 typedef struct picture_t picture_t;
 389
 390 /* Subpictures */
 391 typedef struct spu_t spu_t;
 392 typedef struct subpicture_t subpicture_t;
 393 typedef struct subpicture_region_t subpicture_region_t;
 394
 395 typedef struct image_handler_t image_handler_t;
 396
 397 /* Stream output */
 398 typedef struct sout_instance_t sout_instance_t;
 399
 400 typedef struct sout_input_t sout_input_t;
 401 typedef struct sout_packetizer_input_t sout_packetizer_input_t;
 402
 403 typedef struct sout_access_out_t sout_access_out_t;
 404
 405 typedef struct sout_mux_t sout_mux_t;
 406
 407 typedef struct sout_stream_t    sout_stream_t;
 408
 409 typedef struct config_chain_t       config_chain_t;
 410 typedef struct session_descriptor_t session_descriptor_t;
 411
 412 /* Decoders */
 413 typedef struct decoder_t         decoder_t;
 414
 415 /* Encoders */
 416 typedef struct encoder_t      encoder_t;
 417
 418 /* Filters */
 419 typedef struct filter_t filter_t;
 420
 421 /* Network */
 422 typedef struct vlc_url_t vlc_url_t;
 423
 424 /* Misc */
 425 typedef struct iso639_lang_t iso639_lang_t;
 426
 427 /* block */
 428 typedef struct block_t      block_t;
 429 typedef struct block_fifo_t block_fifo_t;
 430
 431 /* Hashing */
 432 typedef struct vlc_hash_md5_ctx vlc_hash_md5_t;
 433
 434 /* XML */
 435 typedef struct xml_t xml_t;
 436 typedef struct xml_reader_t xml_reader_t;
 437
 438 /* vod server */
 439 typedef struct vod_t     vod_t;
 440 typedef struct vod_media_t vod_media_t;
 441
 442 /* VLM */
 443 typedef struct vlm_t         vlm_t;
 444 typedef struct vlm_message_t vlm_message_t;
 445
 446 /* misc */
 447 typedef struct vlc_meta_t    vlc_meta_t;
 448 typedef struct input_stats_t input_stats_t;
 449 typedef struct addon_entry_t addon_entry_t;
 450
 451 /* Update */
 452 typedef struct update_t update_t;
 453
 454 /**
 455  * VLC value structure
 456  */
 457 typedef union
 458 {
 459     int64_t         i_int;
 460     bool            b_bool;
 461     float           f_float;
 462     char *          psz_string;
 463     void *          p_address;
 464     struct { int32_t x; int32_t y; } coords;
 465
 466 } vlc_value_t;
 467
 468 /*****************************************************************************
 469  * Error values (shouldn't be exposed)
 470  *****************************************************************************/
 471 /** No error */
 472 #define VLC_SUCCESS        (-0)
 473 /** Unspecified error */
 474 #define VLC_EGENERIC       (-1)
 475 /** Not enough memory */
 476 #define VLC_ENOMEM         (-2)
 477 /** Timeout */
 478 #define VLC_ETIMEOUT       (-3)
 479 /** Module not found */
 480 #define VLC_ENOMOD         (-4)
 481 /** Object not found */
 482 #define VLC_ENOOBJ         (-5)
 483 /** Variable not found */
 484 #define VLC_ENOVAR         (-6)
 485 /** Bad variable value */
 486 #define VLC_EBADVAR        (-7)
 487 /** Item not found */
 488 #define VLC_ENOITEM        (-8)
 489
 490 /*****************************************************************************
 491  * Variable callbacks: called when the value is modified
 492  *****************************************************************************/
 493 typedef int ( * vlc_callback_t ) ( vlc_object_t *,      /* variable's object */
 494                                    char const *,            /* variable name */
 495                                    vlc_value_t,                 /* old value */
 496                                    vlc_value_t,                 /* new value */
 497                                    void * );                /* callback data */
 498
 499 /*****************************************************************************
 500  * List callbacks: called when elements are added/removed from the list
 501  *****************************************************************************/
 502 typedef int ( * vlc_list_callback_t ) ( vlc_object_t *,      /* variable's object */
 503                                         char const *,            /* variable name */
 504                                         int,                  /* VLC_VAR_* action */
 505                                         vlc_value_t *,      /* new/deleted value  */
 506                                         void *);                 /* callback data */
 507
 508 /*****************************************************************************
 509  * OS-specific headers and thread types
 510  *****************************************************************************/
 511 #if defined( _WIN32 )
 512 #   include <malloc.h>
 513 #   ifndef PATH_MAX
 514 #       define PATH_MAX MAX_PATH
 515 #   endif
 516 #   include <windows.h>
 517 #endif
 518
 519 #ifdef __APPLE__
 520 #include <sys/syslimits.h>
 521 #include <AvailabilityMacros.h>
 522 #endif
 523
 524 #ifdef __OS2__
 525 #   define OS2EMX_PLAIN_CHAR
 526 #   define INCL_BASE
 527 #   define INCL_PM
 528 #   include <os2safe.h>
 529 #   include <os2.h>
 530 #endif
 531
 532 #include "vlc_tick.h"
 533 #include "vlc_threads.h"
 534
 535 /**
 536  * \defgroup intops Integer operations
 537  * \ingroup cext
 538  *
 539  * Common integer functions.
 540  * @{
 541  */
 542 /* __MAX and __MIN: self explanatory */
 543 #ifndef __MAX
 544 #   define __MAX(a, b)   ( ((a) > (b)) ? (a) : (b) )
 545 #endif
 546 #ifndef __MIN
 547 #   define __MIN(a, b)   ( ((a) < (b)) ? (a) : (b) )
 548 #endif
 549
 550 /* clip v in [min, max] */
 551 #define VLC_CLIP(v, min, max)    __MIN(__MAX((v), (min)), (max))
 552
 553 /**
 554  * Make integer v a multiple of align
 555  *
 556  * \note align must be a power of 2
 557  */
 558 VLC_USED
 559 static inline size_t vlc_align(size_t v, size_t align)
 560 {
 561     return (v + (align - 1)) & ~(align - 1);
 562 }
 563
 564 #if defined(__clang__) && __has_attribute(diagnose_if)
 565 static inline size_t vlc_align(size_t v, size_t align)
 566     __attribute__((diagnose_if(((align & (align - 1)) || (align == 0)),
 567         "align must be power of 2", "error")));
 568 #endif
 569
 570 /** Greatest common divisor */
 571 VLC_USED
 572 static inline int64_t GCD ( int64_t a, int64_t b )
 573 {
 574     while( b )
 575     {
 576         int64_t c = a % b;
 577         a = b;
 578         b = c;
 579     }
 580     return a;
 581 }
 582
 583 /* function imported from libavutil/common.h */
 584 VLC_USED
 585 static inline uint8_t clip_uint8_vlc( int32_t a )
 586 {
 587     if( a&(~255) ) return (-a)>>31;
 588     else           return a;
 589 }
 590
 591 /**
 592  * \defgroup bitops Bit operations
 593  * @{
 594  */
 595
 596 #define VLC_INT_FUNC(basename) \
 597         VLC_INT_FUNC_TYPE(basename, unsigned, ) \
 598         VLC_INT_FUNC_TYPE(basename, unsigned long, l) \
 599         VLC_INT_FUNC_TYPE(basename, unsigned long long, ll)
 600
 601 #if defined (__GNUC__) || defined (__clang__)
 602 # define VLC_INT_FUNC_TYPE(basename,type,suffix) \
 603 VLC_USED static inline int vlc_##basename##suffix(type x) \
 604 { \
 605     return __builtin_##basename##suffix(x); \
 606 }
 607
 608 VLC_INT_FUNC(clz)
 609 #else
 610 VLC_USED static inline int vlc_clzll(unsigned long long x)
 611 {
 612     int i = sizeof (x) * 8;
 613
 614     while (x)
 615     {
 616         x >>= 1;
 617         i--;
 618     }
 619     return i;
 620 }
 621
 622 VLC_USED static inline int vlc_clzl(unsigned long x)
 623 {
 624     return vlc_clzll(x) - ((sizeof (long long) - sizeof (long)) * 8);
 625 }
 626
 627 VLC_USED static inline int vlc_clz(unsigned x)
 628 {
 629     return vlc_clzll(x) - ((sizeof (long long) - sizeof (int)) * 8);
 630 }
 631
 632 VLC_USED static inline int vlc_ctz_generic(unsigned long long x)
 633 {
 634     unsigned i = sizeof (x) * 8;
 635
 636     while (x)
 637     {
 638         x <<= 1;
 639         i--;
 640     }
 641     return i;
 642 }
 643
 644 VLC_USED static inline int vlc_parity_generic(unsigned long long x)
 645 {
 646     for (unsigned i = 4 * sizeof (x); i > 0; i /= 2)
 647         x ^= x >> i;
 648     return x & 1;
 649 }
 650
 651 VLC_USED static inline int vlc_popcount_generic(unsigned long long x)
 652 {
 653     int count = 0;
 654     while (x)
 655     {
 656         count += x & 1;
 657         x = x >> 1;
 658     }
 659     return count;
 660 }
 661
 662 # define VLC_INT_FUNC_TYPE(basename,type,suffix) \
 663 VLC_USED static inline int vlc_##basename##suffix(type x) \
 664 { \
 665     return vlc_##basename##_generic(x); \
 666 }
 667 #endif
 668
 669 VLC_INT_FUNC(ctz)
 670 VLC_INT_FUNC(parity)
 671 VLC_INT_FUNC(popcount)
 672
 673 #ifndef __cplusplus
 674 # define VLC_INT_GENERIC(func,x) \
 675     _Generic((x), \
 676         unsigned char:      func(x), \
 677           signed char:      func(x), \
 678         unsigned short:     func(x), \
 679           signed short:     func(x), \
 680         unsigned int:       func(x), \
 681           signed int:       func(x), \
 682         unsigned long:      func##l(x), \
 683           signed long:      func##l(x), \
 684         unsigned long long: func##ll(x), \
 685           signed long long: func##ll(x))
 686
 687 /**
 688  * Count leading zeroes
 689  *
 690  * This function counts the number of consecutive zero (clear) bits
 691  * down from the highest order bit in an unsigned integer.
 692  *
 693  * \param x a non-zero integer
 694  * \note This macro assumes that CHAR_BIT equals 8.
 695  * \warning By definition, the result depends on the (width of the) type of x.
 696  * \return The number of leading zero bits in x.
 697  */
 698 # define clz(x) \
 699     _Generic((x), \
 700         unsigned char: (vlc_clz(x) - (sizeof (unsigned) - 1) * 8), \
 701         unsigned short: (vlc_clz(x) \
 702         - (sizeof (unsigned) - sizeof (unsigned short)) * 8), \
 703         unsigned: vlc_clz(x), \
 704         unsigned long: vlc_clzl(x), \
 705         unsigned long long: vlc_clzll(x))
 706
 707 /**
 708  * Count trailing zeroes
 709  *
 710  * This function counts the number of consecutive zero bits
 711  * up from the lowest order bit in an unsigned integer.
 712  *
 713  * \param x a non-zero integer
 714  * \note This function assumes that CHAR_BIT equals 8.
 715  * \return The number of trailing zero bits in x.
 716  */
 717 # define ctz(x) VLC_INT_GENERIC(vlc_ctz, x)
 718
 719 /**
 720  * Parity
 721  *
 722  * This function determines the parity of an integer.
 723  * \retval 0 if x has an even number of set bits.
 724  * \retval 1 if x has an odd number of set bits.
 725  */
 726 # define parity(x) VLC_INT_GENERIC(vlc_parity, x)
 727
 728 /**
 729  * Bit weight / population count
 730  *
 731  * This function counts the number of non-zero bits in an integer.
 732  *
 733  * \return The count of non-zero bits.
 734  */
 735 # define vlc_popcount(x) \
 736     _Generic((x), \
 737         signed char:  vlc_popcount((unsigned char)(x)), \
 738         signed short: vlc_popcount((unsigned short)(x)), \
 739         default: VLC_INT_GENERIC(vlc_popcount ,x))
 740 #else
 741 VLC_USED static inline int vlc_popcount(unsigned char x)
 742 {
 743     return vlc_popcount((unsigned)x);
 744 }
 745
 746 VLC_USED static inline int vlc_popcount(unsigned short x)
 747 {
 748     return vlc_popcount((unsigned)x);
 749 }
 750
 751 VLC_USED static inline int vlc_popcount(unsigned long x)
 752 {
 753     return vlc_popcountl(x);
 754 }
 755
 756 VLC_USED static inline int vlc_popcount(unsigned long long x)
 757 {
 758     return vlc_popcountll(x);
 759 }
 760 #endif
 761
 762 /** Byte swap (16 bits) */
 763 VLC_USED
 764 static inline uint16_t vlc_bswap16(uint16_t x)
 765 {
 766     return (x << 8) | (x >> 8);
 767 }
 768
 769 /** Byte swap (32 bits) */
 770 VLC_USED
 771 static inline uint32_t vlc_bswap32(uint32_t x)
 772 {
 773 #if defined (__GNUC__) || defined(__clang__)
 774     return __builtin_bswap32 (x);
 775 #else
 776     return ((x & 0x000000FF) << 24)
 777          | ((x & 0x0000FF00) <<  8)
 778          | ((x & 0x00FF0000) >>  8)
 779          | ((x & 0xFF000000) >> 24);
 780 #endif
 781 }
 782
 783 /** Byte swap (64 bits) */
 784 VLC_USED
 785 static inline uint64_t vlc_bswap64(uint64_t x)
 786 {
 787 #if defined (__GNUC__) || defined(__clang__)
 788     return __builtin_bswap64 (x);
 789 #elif !defined (__cplusplus)
 790     return ((x & 0x00000000000000FF) << 56)
 791          | ((x & 0x000000000000FF00) << 40)
 792          | ((x & 0x0000000000FF0000) << 24)
 793          | ((x & 0x00000000FF000000) <<  8)
 794          | ((x & 0x000000FF00000000) >>  8)
 795          | ((x & 0x0000FF0000000000) >> 24)
 796          | ((x & 0x00FF000000000000) >> 40)
 797          | ((x & 0xFF00000000000000) >> 56);
 798 #else
 799     return ((x & 0x00000000000000FFULL) << 56)
 800          | ((x & 0x000000000000FF00ULL) << 40)
 801          | ((x & 0x0000000000FF0000ULL) << 24)
 802          | ((x & 0x00000000FF000000ULL) <<  8)
 803          | ((x & 0x000000FF00000000ULL) >>  8)
 804          | ((x & 0x0000FF0000000000ULL) >> 24)
 805          | ((x & 0x00FF000000000000ULL) >> 40)
 806          | ((x & 0xFF00000000000000ULL) >> 56);
 807 #endif
 808 }
 809 /** @} */
 810
 811 /**
 812  * \defgroup overflow Overflowing arithmetic
 813  * @{
 814  */
 815 static inline bool uadd_overflow(unsigned a, unsigned b, unsigned *res)
 816 {
 817 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 818      return __builtin_uadd_overflow(a, b, res);
 819 #else
 820      *res = a + b;
 821      return (a + b) < a;
 822 #endif
 823 }
 824
 825 static inline bool uaddl_overflow(unsigned long a, unsigned long b,
 826                                   unsigned long *res)
 827 {
 828 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 829      return __builtin_uaddl_overflow(a, b, res);
 830 #else
 831      *res = a + b;
 832      return (a + b) < a;
 833 #endif
 834 }
 835
 836 static inline bool uaddll_overflow(unsigned long long a, unsigned long long b,
 837                                    unsigned long long *res)
 838 {
 839 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 840      return __builtin_uaddll_overflow(a, b, res);
 841 #else
 842      *res = a + b;
 843      return (a + b) < a;
 844 #endif
 845 }
 846
 847 #ifndef __cplusplus
 848 /**
 849  * Overflowing addition
 850  *
 851  * Converts \p a and \p b to the type of \p *r.
 852  * Then computes the sum of both conversions while checking for overflow.
 853  * Finally stores the result in \p *r.
 854  *
 855  * \param a an integer
 856  * \param b an integer
 857  * \param r a pointer to an integer [OUT]
 858  * \retval false The sum did not overflow.
 859  * \retval true The sum overflowed.
 860  */
 861 # define add_overflow(a,b,r) \
 862     _Generic(*(r), \
 863         unsigned: uadd_overflow(a, b, (unsigned *)(r)), \
 864         unsigned long: uaddl_overflow(a, b, (unsigned long *)(r)), \
 865         unsigned long long: uaddll_overflow(a, b, (unsigned long long *)(r)))
 866 #else
 867 static inline bool add_overflow(unsigned a, unsigned b, unsigned *res)
 868 {
 869     return uadd_overflow(a, b, res);
 870 }
 871
 872 static inline bool add_overflow(unsigned long a, unsigned long b,
 873                                 unsigned long *res)
 874 {
 875     return uaddl_overflow(a, b, res);
 876 }
 877
 878 static inline bool add_overflow(unsigned long long a, unsigned long long b,
 879                                 unsigned long long *res)
 880 {
 881     return uaddll_overflow(a, b, res);
 882 }
 883 #endif
 884
 885 #if !(VLC_GCC_VERSION(5,0) || defined(__clang__))
 886 # include <limits.h>
 887 #endif
 888
 889 static inline bool umul_overflow(unsigned a, unsigned b, unsigned *res)
 890 {
 891 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 892      return __builtin_umul_overflow(a, b, res);
 893 #else
 894      *res = a * b;
 895      return b > 0 && a > (UINT_MAX / b);
 896 #endif
 897 }
 898
 899 static inline bool umull_overflow(unsigned long a, unsigned long b,
 900                                   unsigned long *res)
 901 {
 902 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 903      return __builtin_umull_overflow(a, b, res);
 904 #else
 905      *res = a * b;
 906      return b > 0 && a > (ULONG_MAX / b);
 907 #endif
 908 }
 909
 910 static inline bool umulll_overflow(unsigned long long a, unsigned long long b,
 911                                    unsigned long long *res)
 912 {
 913 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 914      return __builtin_umulll_overflow(a, b, res);
 915 #else
 916      *res = a * b;
 917      return b > 0 && a > (ULLONG_MAX / b);
 918 #endif
 919 }
 920
 921 #ifndef __cplusplus
 922 /**
 923  * Overflowing multiplication
 924  *
 925  * Converts \p a and \p b to the type of \p *r.
 926  * Then computes the product of both conversions while checking for overflow.
 927  * Finally stores the result in \p *r.
 928  *
 929  * \param a an integer
 930  * \param b an integer
 931  * \param r a pointer to an integer [OUT]
 932  * \retval false The product did not overflow.
 933  * \retval true The product overflowed.
 934  */
 935 #define mul_overflow(a,b,r) \
 936     _Generic(*(r), \
 937         unsigned: umul_overflow(a, b, (unsigned *)(r)), \
 938         unsigned long: umull_overflow(a, b, (unsigned long *)(r)), \
 939         unsigned long long: umulll_overflow(a, b, (unsigned long long *)(r)))
 940 #else
 941 static inline bool mul_overflow(unsigned a, unsigned b, unsigned *res)
 942 {
 943     return umul_overflow(a, b, res);
 944 }
 945
 946 static inline bool mul_overflow(unsigned long a, unsigned long b,
 947                                 unsigned long *res)
 948 {
 949     return umull_overflow(a, b, res);
 950 }
 951
 952 static inline bool mul_overflow(unsigned long long a, unsigned long long b,
 953                                 unsigned long long *res)
 954 {
 955     return umulll_overflow(a, b, res);
 956 }
 957 #endif
 958 /** @} */
 959 /** @} */
 960
 961 /* Free and set set the variable to NULL */
 962 #define FREENULL(a) do { free( a ); a = NULL; } while(0)
 963
 964 #define EMPTY_STR(str) (!str || !*str)
 965
 966 #include <vlc_arrays.h>
 967
 968 /* MSB (big endian)/LSB (little endian) conversions - network order is always
 969  * MSB, and should be used for both network communications and files. */
 970
 971 #ifdef WORDS_BIGENDIAN
 972 # define hton16(i) ((uint16_t)(i))
 973 # define hton32(i) ((uint32_t)(i))
 974 # define hton64(i) ((uint64_t)(i))
 975 #else
 976 # define hton16(i) vlc_bswap16(i)
 977 # define hton32(i) vlc_bswap32(i)
 978 # define hton64(i) vlc_bswap64(i)
 979 #endif
 980 #define ntoh16(i) hton16(i)
 981 #define ntoh32(i) hton32(i)
 982 #define ntoh64(i) hton64(i)
 983
 984 /** Reads 16 bits in network byte order */
 985 VLC_USED
 986 static inline uint16_t U16_AT (const void *p)
 987 {
 988     uint16_t x;
 989
 990     memcpy (&x, p, sizeof (x));
 991     return ntoh16 (x);
 992 }
 993
 994 /** Reads 32 bits in network byte order */
 995 VLC_USED
 996 static inline uint32_t U32_AT (const void *p)
 997 {
 998     uint32_t x;
 999
1000     memcpy (&x, p, sizeof (x));
1001     return ntoh32 (x);
1002 }
1003
1004 /** Reads 64 bits in network byte order */
1005 VLC_USED
1006 static inline uint64_t U64_AT (const void *p)
1007 {
1008     uint64_t x;
1009
1010     memcpy (&x, p, sizeof (x));
1011     return ntoh64 (x);
1012 }
1013
1014 #define GetWBE(p)  U16_AT(p)
1015 #define GetDWBE(p) U32_AT(p)
1016 #define GetQWBE(p) U64_AT(p)
1017
1018 /** Reads 16 bits in little-endian order */
1019 VLC_USED
1020 static inline uint16_t GetWLE (const void *p)
1021 {
1022     uint16_t x;
1023
1024     memcpy (&x, p, sizeof (x));
1025 #ifdef WORDS_BIGENDIAN
1026     x = vlc_bswap16 (x);
1027 #endif
1028     return x;
1029 }
1030
1031 /** Reads 32 bits in little-endian order */
1032 VLC_USED
1033 static inline uint32_t GetDWLE (const void *p)
1034 {
1035     uint32_t x;
1036
1037     memcpy (&x, p, sizeof (x));
1038 #ifdef WORDS_BIGENDIAN
1039     x = vlc_bswap32 (x);
1040 #endif
1041     return x;
1042 }
1043
1044 /** Reads 64 bits in little-endian order */
1045 VLC_USED
1046 static inline uint64_t GetQWLE (const void *p)
1047 {
1048     uint64_t x;
1049
1050     memcpy (&x, p, sizeof (x));
1051 #ifdef WORDS_BIGENDIAN
1052     x = vlc_bswap64 (x);
1053 #endif
1054     return x;
1055 }
1056
1057 /** Writes 16 bits in network byte order */
1058 static inline void SetWBE (void *p, uint16_t w)
1059 {
1060     w = hton16 (w);
1061     memcpy (p, &w, sizeof (w));
1062 }
1063
1064 /** Writes 32 bits in network byte order */
1065 static inline void SetDWBE (void *p, uint32_t dw)
1066 {
1067     dw = hton32 (dw);
1068     memcpy (p, &dw, sizeof (dw));
1069 }
1070
1071 /** Writes 64 bits in network byte order */
1072 static inline void SetQWBE (void *p, uint64_t qw)
1073 {
1074     qw = hton64 (qw);
1075     memcpy (p, &qw, sizeof (qw));
1076 }
1077
1078 /** Writes 16 bits in little endian order */
1079 static inline void SetWLE (void *p, uint16_t w)
1080 {
1081 #ifdef WORDS_BIGENDIAN
1082     w = vlc_bswap16 (w);
1083 #endif
1084     memcpy (p, &w, sizeof (w));
1085 }
1086
1087 /** Writes 32 bits in little endian order */
1088 static inline void SetDWLE (void *p, uint32_t dw)
1089 {
1090 #ifdef WORDS_BIGENDIAN
1091     dw = vlc_bswap32 (dw);
1092 #endif
1093     memcpy (p, &dw, sizeof (dw));
1094 }
1095
1096 /** Writes 64 bits in little endian order */
1097 static inline void SetQWLE (void *p, uint64_t qw)
1098 {
1099 #ifdef WORDS_BIGENDIAN
1100     qw = vlc_bswap64 (qw);
1101 #endif
1102     memcpy (p, &qw, sizeof (qw));
1103 }
1104
1105 /* */
1106 #define VLC_UNUSED(x) (void)(x)
1107
1108 /* Stuff defined in src/extras/libc.c */
1109
1110 #if defined(_WIN32)
1111 /* several type definitions */
1112 #   if defined( __MINGW32__ )
1113 #       if !defined( _OFF_T_ )
1114             typedef long long _off_t;
1115             typedef _off_t off_t;
1116 #           define _OFF_T_
1117 #       else
1118 #           ifdef off_t
1119 #               undef off_t
1120 #           endif
1121 #           define off_t long long
1122 #       endif
1123 #   endif
1124
1125 #   ifndef O_NONBLOCK
1126 #       define O_NONBLOCK 0
1127 #   endif
1128
1129 /* the mingw32 swab() and win32 _swab() prototypes expect a char* instead of a
1130    const void* */
1131 #  define swab(a,b,c)  swab((char*) (a), (char*) (b), (c))
1132
1133 #endif /* _WIN32 */
1134
1135 typedef struct {
1136     unsigned num, den;
1137 } vlc_rational_t;
1138
1139 VLC_API bool vlc_ureduce( unsigned *, unsigned *, uint64_t, uint64_t, uint64_t );
1140
1141 #define container_of(ptr, type, member) \
1142     ((type *)(((char *)(ptr)) - offsetof(type, member)))
1143
1144 VLC_USED VLC_MALLOC
1145 static inline void *vlc_alloc(size_t count, size_t size)
1146 {
1147     return mul_overflow(count, size, &size) ? NULL : malloc(size);
1148 }
1149
1150 VLC_USED
1151 static inline void *vlc_reallocarray(void *ptr, size_t count, size_t size)
1152 {
1153     return mul_overflow(count, size, &size) ? NULL : realloc(ptr, size);
1154 }
1155
1156 /*****************************************************************************
1157  * I18n stuff
1158  *****************************************************************************/
1159 VLC_API const char *vlc_gettext(const char *msgid) VLC_FORMAT_ARG(1);
1160 VLC_API const char *vlc_ngettext(const char *s, const char *p, unsigned long n)
1161 VLC_FORMAT_ARG(1) VLC_FORMAT_ARG(2);
1162
1163 #define vlc_pgettext( ctx, id ) \
1164         vlc_pgettext_aux( ctx "\004" id, id )
1165
1166 VLC_FORMAT_ARG(2)
1167 static inline const char *vlc_pgettext_aux( const char *ctx, const char *id )
1168 {
1169     const char *tr = vlc_gettext( ctx );
1170     return (tr == ctx) ? id : tr;
1171 }
1172
1173 /*****************************************************************************
1174  * Loosy memory allocation functions. Do not use in new code.
1175  *****************************************************************************/
1176 static inline void *xmalloc(size_t len)
1177 {
1178     void *ptr = malloc(len);
1179     if (unlikely(ptr == NULL && len > 0))
1180         abort();
1181     return ptr;
1182 }
1183
1184 static inline void *xrealloc(void *ptr, size_t len)
1185 {
1186     void *nptr = realloc(ptr, len);
1187     if (unlikely(nptr == NULL && len > 0))
1188         abort();
1189     return nptr;
1190 }
1191
1192 static inline char *xstrdup (const char *str)
1193 {
1194     char *ptr = strdup (str);
1195     if (unlikely(ptr == NULL))
1196         abort ();
1197     return ptr;
1198 }
1199
1200 /*****************************************************************************
1201  * libvlc features
1202  *****************************************************************************/
1203 VLC_API const char * VLC_CompileBy( void ) VLC_USED;
1204 VLC_API const char * VLC_CompileHost( void ) VLC_USED;
1205 VLC_API const char * VLC_Compiler( void ) VLC_USED;
1206
1207 /*****************************************************************************
1208  * Additional vlc stuff
1209  *****************************************************************************/
1210 #include "vlc_messages.h"
1211 #include "vlc_objects.h"
1212 #include "vlc_variables.h"
1213 #include "vlc_configuration.h"
1214
1215 #if defined( _WIN32 ) || defined( __OS2__ )
1216 #   define DIR_SEP_CHAR '\\'
1217 #   define DIR_SEP "\\"
1218 #   define PATH_SEP_CHAR ';'
1219 #   define PATH_SEP ";"
1220 #else
1221 #   define DIR_SEP_CHAR '/'
1222 #   define DIR_SEP "/"
1223 #   define PATH_SEP_CHAR ':'
1224 #   define PATH_SEP ":"
1225 #endif
1226
1227 #define LICENSE_MSG \
1228   _("This program comes with NO WARRANTY, to the extent permitted by " \
1229     "law.\nYou may redistribute it under the terms of the GNU General " \
1230     "Public License;\nsee the file named COPYING for details.\n" \
1231     "Written by the VideoLAN team; see the AUTHORS file.\n")
1232
1233 #endif /* !VLC_COMMON_H */