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 #ifdef __ELF__
 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 #else
 207 /**
 208  * Predicted true condition
 209  *
 210  * This macro indicates that the condition is expected most often true.
 211  * The compiler may optimize the code assuming that this condition is usually
 212  * met.
 213  */
 214 # define likely(p)     (!!(p))
 215
 216 /**
 217  * Predicted false condition
 218  *
 219  * This macro indicates that the condition is expected most often false.
 220  * The compiler may optimize the code assuming that this condition is rarely
 221  * met.
 222  */
 223 # define unlikely(p)   (!!(p))
 224
 225 /**
 226  * Impossible branch
 227  *
 228  * This macro indicates that the branch cannot be reached at run-time, and
 229  * represents undefined behaviour.
 230  * The compiler may optimize the code assuming that the call flow will never
 231  * logically reach the point where this macro is expanded.
 232  *
 233  * See also \ref vlc_assert_unreachable.
 234  */
 235 # define unreachable() ((void)0)
 236 #endif
 237
 238 /**
 239  * Impossible branch assertion
 240  *
 241  * This macro asserts that the branch cannot be reached at run-time.
 242  *
 243  * If the branch is reached in a debug build, it will trigger an assertion
 244  * failure and abnormal program termination.
 245  *
 246  * If the branch is reached in a non-debug build, this macro is equivalent to
 247  * \ref unreachable and the behaviour is undefined.
 248  */
 249 #define vlc_assert_unreachable() (assert(!"unreachable"), unreachable())
 250
 251 /* Linkage */
 252 #ifdef __cplusplus
 253 # define VLC_EXTERN extern "C"
 254 #else
 255 # define VLC_EXTERN
 256 #endif
 257
 258 #if defined (_WIN32) && defined (DLL_EXPORT)
 259 # define VLC_EXPORT __declspec(dllexport)
 260 #elif defined (__GNUC__)
 261 # define VLC_EXPORT __attribute__((visibility("default")))
 262 #else
 263 # define VLC_EXPORT
 264 #endif
 265
 266 /**
 267  * Exported API call annotation
 268  *
 269  * This macro is placed before a function declaration to indicate that the
 270  * function is an API call of the LibVLC plugin API.
 271  */
 272 #define VLC_API VLC_EXTERN VLC_EXPORT
 273
 274 /** @} */
 275
 276 /*****************************************************************************
 277  * Basic types definitions
 278  *****************************************************************************/
 279 /**
 280  * High precision date or time interval
 281  *
 282  * Store a high precision date or time interval. The maximum precision is the
 283  * microsecond, and a 64 bits integer is used to avoid overflows (maximum
 284  * time interval is then 292271 years, which should be long enough for any
 285  * video). Dates are stored as microseconds since a common date (usually the
 286  * epoch). Note that date and time intervals can be manipulated using regular
 287  * arithmetic operators, and that no special functions are required.
 288  */
 289 typedef int64_t mtime_t;
 290
 291 /**
 292  * The vlc_fourcc_t type.
 293  *
 294  * See http://www.webartz.com/fourcc/ for a very detailed list.
 295  */
 296 typedef uint32_t vlc_fourcc_t;
 297
 298 #ifdef WORDS_BIGENDIAN
 299 #   define VLC_FOURCC( a, b, c, d ) \
 300         ( ((uint32_t)d) | ( ((uint32_t)c) << 8 ) \
 301            | ( ((uint32_t)b) << 16 ) | ( ((uint32_t)a) << 24 ) )
 302 #   define VLC_TWOCC( a, b ) \
 303         ( (uint16_t)(b) | ( (uint16_t)(a) << 8 ) )
 304
 305 #else
 306 #   define VLC_FOURCC( a, b, c, d ) \
 307         ( ((uint32_t)a) | ( ((uint32_t)b) << 8 ) \
 308            | ( ((uint32_t)c) << 16 ) | ( ((uint32_t)d) << 24 ) )
 309 #   define VLC_TWOCC( a, b ) \
 310         ( (uint16_t)(a) | ( (uint16_t)(b) << 8 ) )
 311
 312 #endif
 313
 314 /**
 315  * Translate a vlc_fourcc into its string representation. This function
 316  * assumes there is enough room in psz_fourcc to store 4 characters in.
 317  *
 318  * \param fcc a vlc_fourcc_t
 319  * \param psz_fourcc string to store string representation of vlc_fourcc in
 320  */
 321 static inline void vlc_fourcc_to_char( vlc_fourcc_t fcc, char *psz_fourcc )
 322 {
 323     memcpy( psz_fourcc, &fcc, 4 );
 324 }
 325
 326 /*****************************************************************************
 327  * Classes declaration
 328  *****************************************************************************/
 329
 330 /* Internal types */
 331 typedef struct vlc_object_t vlc_object_t;
 332 typedef struct libvlc_int_t libvlc_int_t;
 333 typedef struct date_t date_t;
 334
 335 /* Playlist */
 336
 337 typedef struct playlist_t playlist_t;
 338 typedef struct playlist_item_t playlist_item_t;
 339 typedef struct services_discovery_t services_discovery_t;
 340 typedef struct vlc_renderer_discovery_t vlc_renderer_discovery_t;
 341 typedef struct vlc_renderer_item_t vlc_renderer_item_t;
 342
 343 /* Modules */
 344 typedef struct module_t module_t;
 345 typedef struct module_config_t module_config_t;
 346
 347 typedef struct config_category_t config_category_t;
 348
 349 /* Input */
 350 typedef struct input_thread_t input_thread_t;
 351 typedef struct input_item_t input_item_t;
 352 typedef struct input_item_node_t input_item_node_t;
 353 typedef struct stream_t     stream_t;
 354 typedef struct stream_t demux_t;
 355 typedef struct es_out_t     es_out_t;
 356 typedef struct es_out_id_t  es_out_id_t;
 357 typedef struct seekpoint_t seekpoint_t;
 358 typedef struct info_t info_t;
 359 typedef struct info_category_t info_category_t;
 360 typedef struct input_attachment_t input_attachment_t;
 361
 362 /* Format */
 363 typedef struct audio_format_t audio_format_t;
 364 typedef struct video_format_t video_format_t;
 365 typedef struct subs_format_t subs_format_t;
 366 typedef struct es_format_t es_format_t;
 367 typedef struct video_palette_t video_palette_t;
 368
 369 /* Audio */
 370 typedef struct audio_output audio_output_t;
 371 typedef audio_format_t audio_sample_format_t;
 372
 373 /* Video */
 374 typedef struct vout_thread_t vout_thread_t;
 375 typedef struct vlc_viewpoint_t vlc_viewpoint_t;
 376
 377 typedef video_format_t video_frame_format_t;
 378 typedef struct picture_t picture_t;
 379
 380 /* Subpictures */
 381 typedef struct spu_t spu_t;
 382 typedef struct subpicture_t subpicture_t;
 383 typedef struct subpicture_region_t subpicture_region_t;
 384
 385 typedef struct image_handler_t image_handler_t;
 386
 387 /* Stream output */
 388 typedef struct sout_instance_t sout_instance_t;
 389
 390 typedef struct sout_input_t sout_input_t;
 391 typedef struct sout_packetizer_input_t sout_packetizer_input_t;
 392
 393 typedef struct sout_access_out_t sout_access_out_t;
 394
 395 typedef struct sout_mux_t sout_mux_t;
 396
 397 typedef struct sout_stream_t    sout_stream_t;
 398
 399 typedef struct config_chain_t       config_chain_t;
 400 typedef struct session_descriptor_t session_descriptor_t;
 401
 402 /* Decoders */
 403 typedef struct decoder_t         decoder_t;
 404 typedef struct decoder_synchro_t decoder_synchro_t;
 405
 406 /* Encoders */
 407 typedef struct encoder_t      encoder_t;
 408
 409 /* Filters */
 410 typedef struct filter_t filter_t;
 411
 412 /* Network */
 413 typedef struct vlc_url_t vlc_url_t;
 414
 415 /* Misc */
 416 typedef struct iso639_lang_t iso639_lang_t;
 417
 418 /* block */
 419 typedef struct block_t      block_t;
 420 typedef struct block_fifo_t block_fifo_t;
 421
 422 /* Hashing */
 423 typedef struct md5_s md5_t;
 424
 425 /* XML */
 426 typedef struct xml_t xml_t;
 427 typedef struct xml_reader_t xml_reader_t;
 428
 429 /* vod server */
 430 typedef struct vod_t     vod_t;
 431 typedef struct vod_media_t vod_media_t;
 432
 433 /* VLM */
 434 typedef struct vlm_t         vlm_t;
 435 typedef struct vlm_message_t vlm_message_t;
 436
 437 /* misc */
 438 typedef struct vlc_meta_t    vlc_meta_t;
 439 typedef struct input_stats_t input_stats_t;
 440 typedef struct addon_entry_t addon_entry_t;
 441
 442 /* Update */
 443 typedef struct update_t update_t;
 444
 445 /**
 446  * VLC value structure
 447  */
 448 typedef union
 449 {
 450     int64_t         i_int;
 451     bool            b_bool;
 452     float           f_float;
 453     char *          psz_string;
 454     void *          p_address;
 455     struct { int32_t x; int32_t y; } coords;
 456
 457 } vlc_value_t;
 458
 459 /*****************************************************************************
 460  * Error values (shouldn't be exposed)
 461  *****************************************************************************/
 462 #define VLC_SUCCESS        (-0) /**< No error */
 463 #define VLC_EGENERIC       (-1) /**< Unspecified error */
 464 #define VLC_ENOMEM         (-2) /**< Not enough memory */
 465 #define VLC_ETIMEOUT       (-3) /**< Timeout */
 466 #define VLC_ENOMOD         (-4) /**< Module not found */
 467 #define VLC_ENOOBJ         (-5) /**< Object not found */
 468 #define VLC_ENOVAR         (-6) /**< Variable not found */
 469 #define VLC_EBADVAR        (-7) /**< Bad variable value */
 470 #define VLC_ENOITEM        (-8) /**< Item not found */
 471
 472 /*****************************************************************************
 473  * Variable callbacks: called when the value is modified
 474  *****************************************************************************/
 475 typedef int ( * vlc_callback_t ) ( vlc_object_t *,      /* variable's object */
 476                                    char const *,            /* variable name */
 477                                    vlc_value_t,                 /* old value */
 478                                    vlc_value_t,                 /* new value */
 479                                    void * );                /* callback data */
 480
 481 /*****************************************************************************
 482  * List callbacks: called when elements are added/removed from the list
 483  *****************************************************************************/
 484 typedef int ( * vlc_list_callback_t ) ( vlc_object_t *,      /* variable's object */
 485                                         char const *,            /* variable name */
 486                                         int,                  /* VLC_VAR_* action */
 487                                         vlc_value_t *,      /* new/deleted value  */
 488                                         void *);                 /* callback data */
 489
 490 /*****************************************************************************
 491  * OS-specific headers and thread types
 492  *****************************************************************************/
 493 #if defined( _WIN32 )
 494 #   include <malloc.h>
 495 #   ifndef PATH_MAX
 496 #       define PATH_MAX MAX_PATH
 497 #   endif
 498 #   include <windows.h>
 499 #endif
 500
 501 #ifdef __APPLE__
 502 #include <sys/syslimits.h>
 503 #include <AvailabilityMacros.h>
 504 #endif
 505
 506 #ifdef __OS2__
 507 #   define OS2EMX_PLAIN_CHAR
 508 #   define INCL_BASE
 509 #   define INCL_PM
 510 #   include <os2safe.h>
 511 #   include <os2.h>
 512 #endif
 513
 514 #include "vlc_mtime.h"
 515 #include "vlc_threads.h"
 516
 517 /**
 518  * \defgroup intops Integer operations
 519  * \ingroup cext
 520  *
 521  * Common integer functions.
 522  * @{
 523  */
 524 /* __MAX and __MIN: self explanatory */
 525 #ifndef __MAX
 526 #   define __MAX(a, b)   ( ((a) > (b)) ? (a) : (b) )
 527 #endif
 528 #ifndef __MIN
 529 #   define __MIN(a, b)   ( ((a) < (b)) ? (a) : (b) )
 530 #endif
 531
 532 /* clip v in [min, max] */
 533 #define VLC_CLIP(v, min, max)    __MIN(__MAX((v), (min)), (max))
 534
 535 /** Greatest common divisor */
 536 VLC_USED
 537 static inline int64_t GCD ( int64_t a, int64_t b )
 538 {
 539     while( b )
 540     {
 541         int64_t c = a % b;
 542         a = b;
 543         b = c;
 544     }
 545     return a;
 546 }
 547
 548 /* function imported from libavutil/common.h */
 549 VLC_USED
 550 static inline uint8_t clip_uint8_vlc( int32_t a )
 551 {
 552     if( a&(~255) ) return (-a)>>31;
 553     else           return a;
 554 }
 555
 556 /**
 557  * \defgroup bitops Bit operations
 558  * @{
 559  */
 560
 561 #define VLC_INT_FUNC(basename) \
 562         VLC_INT_FUNC_TYPE(basename, unsigned, ) \
 563         VLC_INT_FUNC_TYPE(basename, unsigned long, l) \
 564         VLC_INT_FUNC_TYPE(basename, unsigned long long, ll)
 565
 566 #if defined (__GNUC__) || defined (__clang__)
 567 # define VLC_INT_FUNC_TYPE(basename,type,suffix) \
 568 VLC_USED static inline int vlc_##basename##suffix(type x) \
 569 { \
 570     return __builtin_##basename##suffix(x); \
 571 }
 572
 573 VLC_INT_FUNC(clz)
 574 #else
 575 VLC_USED static inline int vlc_clzll(unsigned long long x)
 576 {
 577     int i = sizeof (x) * 8;
 578
 579     while (x)
 580     {
 581         x >>= 1;
 582         i--;
 583     }
 584     return i;
 585 }
 586
 587 VLC_USED static inline int vlc_clzl(unsigned long x)
 588 {
 589     return vlc_clzll(x) - ((sizeof (long long) - sizeof (long)) * 8);
 590 }
 591
 592 VLC_USED static inline int vlc_clz(unsigned x)
 593 {
 594     return vlc_clzll(x) - ((sizeof (long long) - sizeof (int)) * 8);
 595 }
 596
 597 VLC_USED static inline int vlc_ctz_generic(unsigned long long x)
 598 {
 599     unsigned i = sizeof (x) * 8;
 600
 601     while (x)
 602     {
 603         x <<= 1;
 604         i--;
 605     }
 606     return i;
 607 }
 608
 609 VLC_USED static inline int vlc_parity_generic(unsigned long long x)
 610 {
 611     for (unsigned i = 4 * sizeof (x); i > 0; i /= 2)
 612         x ^= x >> i;
 613     return x & 1;
 614 }
 615
 616 VLC_USED static inline int vlc_popcount_generic(unsigned long long x)
 617 {
 618     int count = 0;
 619     while (x)
 620     {
 621         count += x & 1;
 622         x = x >> 1;
 623     }
 624     return count;
 625 }
 626
 627 # define VLC_INT_FUNC_TYPE(basename,type,suffix) \
 628 VLC_USED static inline int vlc_##basename##suffix(type x) \
 629 { \
 630     return vlc_##basename##_generic(x); \
 631 }
 632 #endif
 633
 634 VLC_INT_FUNC(ctz)
 635 VLC_INT_FUNC(parity)
 636 VLC_INT_FUNC(popcount)
 637
 638 #ifndef __cplusplus
 639 # define VLC_INT_GENERIC(func,x) \
 640     _Generic((x), \
 641         unsigned char:      func(x), \
 642           signed char:      func(x), \
 643         unsigned short:     func(x), \
 644           signed short:     func(x), \
 645         unsigned int:       func(x), \
 646           signed int:       func(x), \
 647         unsigned long:      func##l(x), \
 648           signed long:      func##l(x), \
 649         unsigned long long: func##ll(x), \
 650           signed long long: func##ll(x))
 651
 652 /**
 653  * Count leading zeroes
 654  *
 655  * This function counts the number of consecutive zero (clear) bits
 656  * down from the highest order bit in an unsigned integer.
 657  *
 658  * \param x a non-zero integer
 659  * \note This macro assumes that CHAR_BIT equals 8.
 660  * \warning By definition, the result depends on the (width of the) type of x.
 661  * \return The number of leading zero bits in x.
 662  */
 663 # define clz(x) \
 664     _Generic((x), \
 665         unsigned char: (vlc_clz(x) - (sizeof (unsigned) - 1) * 8), \
 666         unsigned short: (vlc_clz(x) \
 667                 - (sizeof (unsigned) - sizeof (unsigned short)) * 8), \
 668         unsigned: vlc_clz(x), \
 669         unsigned long: vlc_clzl(x), \
 670         unsigned long long: vlc_clzll(x))
 671
 672 /**
 673  * Count trailing zeroes
 674  *
 675  * This function counts the number of consecutive zero bits
 676  * up from the lowest order bit in an unsigned integer.
 677  *
 678  * \param x a non-zero integer
 679  * \note This function assumes that CHAR_BIT equals 8.
 680  * \return The number of trailing zero bits in x.
 681  */
 682 # define ctz(x) VLC_INT_GENERIC(vlc_ctz, x)
 683
 684 /**
 685  * Parity
 686  *
 687  * This function determines the parity of an integer.
 688  * \retval 0 if x has an even number of set bits.
 689  * \retval 1 if x has an odd number of set bits.
 690  */
 691 # define parity(x) VLC_INT_GENERIC(vlc_parity, x)
 692
 693 /**
 694  * Bit weight / population count
 695  *
 696  * This function counts the number of non-zero bits in an integer.
 697  *
 698  * \return The count of non-zero bits.
 699  */
 700 # define vlc_popcount(x) \
 701     _Generic((x), \
 702         signed char:  vlc_popcount((unsigned char)(x)), \
 703         signed short: vlc_popcount((unsigned short)(x)), \
 704         default: VLC_INT_GENERIC(vlc_popcount ,x))
 705 #else
 706 VLC_USED static inline int vlc_popcount(unsigned char x)
 707 {
 708     return vlc_popcount((unsigned)x);
 709 }
 710
 711 VLC_USED static inline int vlc_popcount(unsigned short x)
 712 {
 713     return vlc_popcount((unsigned)x);
 714 }
 715
 716 VLC_USED static inline int vlc_popcount(unsigned long x)
 717 {
 718     return vlc_popcountl(x);
 719 }
 720
 721 VLC_USED static inline int vlc_popcount(unsigned long long x)
 722 {
 723     return vlc_popcountll(x);
 724 }
 725 #endif
 726
 727 /** Byte swap (16 bits) */
 728 VLC_USED
 729 static inline uint16_t vlc_bswap16(uint16_t x)
 730 {
 731     return (x << 8) | (x >> 8);
 732 }
 733
 734 /** Byte swap (32 bits) */
 735 VLC_USED
 736 static inline uint32_t vlc_bswap32(uint32_t x)
 737 {
 738 #if defined (__GNUC__) || defined(__clang__)
 739     return __builtin_bswap32 (x);
 740 #else
 741     return ((x & 0x000000FF) << 24)
 742          | ((x & 0x0000FF00) <<  8)
 743          | ((x & 0x00FF0000) >>  8)
 744          | ((x & 0xFF000000) >> 24);
 745 #endif
 746 }
 747
 748 /** Byte swap (64 bits) */
 749 VLC_USED
 750 static inline uint64_t vlc_bswap64(uint64_t x)
 751 {
 752 #if defined (__GNUC__) || defined(__clang__)
 753     return __builtin_bswap64 (x);
 754 #elif !defined (__cplusplus)
 755     return ((x & 0x00000000000000FF) << 56)
 756          | ((x & 0x000000000000FF00) << 40)
 757          | ((x & 0x0000000000FF0000) << 24)
 758          | ((x & 0x00000000FF000000) <<  8)
 759          | ((x & 0x000000FF00000000) >>  8)
 760          | ((x & 0x0000FF0000000000) >> 24)
 761          | ((x & 0x00FF000000000000) >> 40)
 762          | ((x & 0xFF00000000000000) >> 56);
 763 #else
 764     return ((x & 0x00000000000000FFULL) << 56)
 765          | ((x & 0x000000000000FF00ULL) << 40)
 766          | ((x & 0x0000000000FF0000ULL) << 24)
 767          | ((x & 0x00000000FF000000ULL) <<  8)
 768          | ((x & 0x000000FF00000000ULL) >>  8)
 769          | ((x & 0x0000FF0000000000ULL) >> 24)
 770          | ((x & 0x00FF000000000000ULL) >> 40)
 771          | ((x & 0xFF00000000000000ULL) >> 56);
 772 #endif
 773 }
 774 /** @} */
 775
 776 /**
 777  * \defgroup overflow Overflowing arithmetic
 778  * @{
 779  */
 780 static inline bool uadd_overflow(unsigned a, unsigned b, unsigned *res)
 781 {
 782 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 783      return __builtin_uadd_overflow(a, b, res);
 784 #else
 785      *res = a + b;
 786      return (a + b) < a;
 787 #endif
 788 }
 789
 790 static inline bool uaddl_overflow(unsigned long a, unsigned long b,
 791                                   unsigned long *res)
 792 {
 793 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 794      return __builtin_uaddl_overflow(a, b, res);
 795 #else
 796      *res = a + b;
 797      return (a + b) < a;
 798 #endif
 799 }
 800
 801 static inline bool uaddll_overflow(unsigned long long a, unsigned long long b,
 802                                    unsigned long long *res)
 803 {
 804 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 805      return __builtin_uaddll_overflow(a, b, res);
 806 #else
 807      *res = a + b;
 808      return (a + b) < a;
 809 #endif
 810 }
 811
 812 #ifndef __cplusplus
 813 /**
 814  * Overflowing addition
 815  *
 816  * Converts \p a and \p b to the type of \p *r.
 817  * Then computes the sum of both conversions while checking for overflow.
 818  * Finally stores the result in \p *r.
 819  *
 820  * \param a an integer
 821  * \param b an integer
 822  * \param r a pointer to an integer [OUT]
 823  * \retval false The sum did not overflow.
 824  * \retval true The sum overflowed.
 825  */
 826 # define add_overflow(a,b,r) \
 827     _Generic(*(r), \
 828         unsigned: uadd_overflow(a, b, (unsigned *)(r)), \
 829         unsigned long: uaddl_overflow(a, b, (unsigned long *)(r)), \
 830         unsigned long long: uaddll_overflow(a, b, (unsigned long long *)(r)))
 831 #else
 832 static inline bool add_overflow(unsigned a, unsigned b, unsigned *res)
 833 {
 834     return uadd_overflow(a, b, res);
 835 }
 836
 837 static inline bool add_overflow(unsigned long a, unsigned long b,
 838                                 unsigned long *res)
 839 {
 840     return uaddl_overflow(a, b, res);
 841 }
 842
 843 static inline bool add_overflow(unsigned long long a, unsigned long long b,
 844                                 unsigned long long *res)
 845 {
 846     return uaddll_overflow(a, b, res);
 847 }
 848 #endif
 849
 850 #if !(VLC_GCC_VERSION(5,0) || defined(__clang__))
 851 # include <limits.h>
 852 #endif
 853
 854 static inline bool umul_overflow(unsigned a, unsigned b, unsigned *res)
 855 {
 856 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 857      return __builtin_umul_overflow(a, b, res);
 858 #else
 859      *res = a * b;
 860      return b > 0 && a > (UINT_MAX / b);
 861 #endif
 862 }
 863
 864 static inline bool umull_overflow(unsigned long a, unsigned long b,
 865                                   unsigned long *res)
 866 {
 867 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 868      return __builtin_umull_overflow(a, b, res);
 869 #else
 870      *res = a * b;
 871      return b > 0 && a > (ULONG_MAX / b);
 872 #endif
 873 }
 874
 875 static inline bool umulll_overflow(unsigned long long a, unsigned long long b,
 876                                    unsigned long long *res)
 877 {
 878 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 879      return __builtin_umulll_overflow(a, b, res);
 880 #else
 881      *res = a * b;
 882      return b > 0 && a > (ULLONG_MAX / b);
 883 #endif
 884 }
 885
 886 #ifndef __cplusplus
 887 /**
 888  * Overflowing multiplication
 889  *
 890  * Converts \p a and \p b to the type of \p *r.
 891  * Then computes the product of both conversions while checking for overflow.
 892  * Finally stores the result in \p *r.
 893  *
 894  * \param a an integer
 895  * \param b an integer
 896  * \param r a pointer to an integer [OUT]
 897  * \retval false The product did not overflow.
 898  * \retval true The product overflowed.
 899  */
 900 #define mul_overflow(a,b,r) \
 901     _Generic(*(r), \
 902         unsigned: umul_overflow(a, b, (unsigned *)(r)), \
 903         unsigned long: umull_overflow(a, b, (unsigned long *)(r)), \
 904         unsigned long long: umulll_overflow(a, b, (unsigned long long *)(r)))
 905 #else
 906 static inline bool mul_overflow(unsigned a, unsigned b, unsigned *res)
 907 {
 908     return umul_overflow(a, b, res);
 909 }
 910
 911 static inline bool mul_overflow(unsigned long a, unsigned long b,
 912                                 unsigned long *res)
 913 {
 914     return umull_overflow(a, b, res);
 915 }
 916
 917 static inline bool mul_overflow(unsigned long long a, unsigned long long b,
 918                                 unsigned long long *res)
 919 {
 920     return umulll_overflow(a, b, res);
 921 }
 922 #endif
 923 /** @} */
 924 /** @} */
 925
 926 /* Free and set set the variable to NULL */
 927 #define FREENULL(a) do { free( a ); a = NULL; } while(0)
 928
 929 #define EMPTY_STR(str) (!str || !*str)
 930
 931 VLC_API char const * vlc_error( int ) VLC_USED;
 932
 933 #include <vlc_arrays.h>
 934
 935 /* MSB (big endian)/LSB (little endian) conversions - network order is always
 936  * MSB, and should be used for both network communications and files. */
 937
 938 #ifdef WORDS_BIGENDIAN
 939 # define hton16(i) ((uint16_t)(i))
 940 # define hton32(i) ((uint32_t)(i))
 941 # define hton64(i) ((uint64_t)(i))
 942 #else
 943 # define hton16(i) vlc_bswap16(i)
 944 # define hton32(i) vlc_bswap32(i)
 945 # define hton64(i) vlc_bswap64(i)
 946 #endif
 947 #define ntoh16(i) hton16(i)
 948 #define ntoh32(i) hton32(i)
 949 #define ntoh64(i) hton64(i)
 950
 951 /** Reads 16 bits in network byte order */
 952 VLC_USED
 953 static inline uint16_t U16_AT (const void *p)
 954 {
 955     uint16_t x;
 956
 957     memcpy (&x, p, sizeof (x));
 958     return ntoh16 (x);
 959 }
 960
 961 /** Reads 32 bits in network byte order */
 962 VLC_USED
 963 static inline uint32_t U32_AT (const void *p)
 964 {
 965     uint32_t x;
 966
 967     memcpy (&x, p, sizeof (x));
 968     return ntoh32 (x);
 969 }
 970
 971 /** Reads 64 bits in network byte order */
 972 VLC_USED
 973 static inline uint64_t U64_AT (const void *p)
 974 {
 975     uint64_t x;
 976
 977     memcpy (&x, p, sizeof (x));
 978     return ntoh64 (x);
 979 }
 980
 981 #define GetWBE(p)  U16_AT(p)
 982 #define GetDWBE(p) U32_AT(p)
 983 #define GetQWBE(p) U64_AT(p)
 984
 985 /** Reads 16 bits in little-endian order */
 986 VLC_USED
 987 static inline uint16_t GetWLE (const void *p)
 988 {
 989     uint16_t x;
 990
 991     memcpy (&x, p, sizeof (x));
 992 #ifdef WORDS_BIGENDIAN
 993     x = vlc_bswap16 (x);
 994 #endif
 995     return x;
 996 }
 997
 998 /** Reads 32 bits in little-endian order */
 999 VLC_USED
1000 static inline uint32_t GetDWLE (const void *p)
1001 {
1002     uint32_t x;
1003
1004     memcpy (&x, p, sizeof (x));
1005 #ifdef WORDS_BIGENDIAN
1006     x = vlc_bswap32 (x);
1007 #endif
1008     return x;
1009 }
1010
1011 /** Reads 64 bits in little-endian order */
1012 VLC_USED
1013 static inline uint64_t GetQWLE (const void *p)
1014 {
1015     uint64_t x;
1016
1017     memcpy (&x, p, sizeof (x));
1018 #ifdef WORDS_BIGENDIAN
1019     x = vlc_bswap64 (x);
1020 #endif
1021     return x;
1022 }
1023
1024 /** Writes 16 bits in network byte order */
1025 static inline void SetWBE (void *p, uint16_t w)
1026 {
1027     w = hton16 (w);
1028     memcpy (p, &w, sizeof (w));
1029 }
1030
1031 /** Writes 32 bits in network byte order */
1032 static inline void SetDWBE (void *p, uint32_t dw)
1033 {
1034     dw = hton32 (dw);
1035     memcpy (p, &dw, sizeof (dw));
1036 }
1037
1038 /** Writes 64 bits in network byte order */
1039 static inline void SetQWBE (void *p, uint64_t qw)
1040 {
1041     qw = hton64 (qw);
1042     memcpy (p, &qw, sizeof (qw));
1043 }
1044
1045 /** Writes 16 bits in little endian order */
1046 static inline void SetWLE (void *p, uint16_t w)
1047 {
1048 #ifdef WORDS_BIGENDIAN
1049     w = vlc_bswap16 (w);
1050 #endif
1051     memcpy (p, &w, sizeof (w));
1052 }
1053
1054 /** Writes 32 bits in little endian order */
1055 static inline void SetDWLE (void *p, uint32_t dw)
1056 {
1057 #ifdef WORDS_BIGENDIAN
1058     dw = vlc_bswap32 (dw);
1059 #endif
1060     memcpy (p, &dw, sizeof (dw));
1061 }
1062
1063 /** Writes 64 bits in little endian order */
1064 static inline void SetQWLE (void *p, uint64_t qw)
1065 {
1066 #ifdef WORDS_BIGENDIAN
1067     qw = vlc_bswap64 (qw);
1068 #endif
1069     memcpy (p, &qw, sizeof (qw));
1070 }
1071
1072 /* */
1073 #define VLC_UNUSED(x) (void)(x)
1074
1075 /* Stuff defined in src/extras/libc.c */
1076
1077 #if defined(_WIN32)
1078 /* several type definitions */
1079 #   if defined( __MINGW32__ )
1080 #       if !defined( _OFF_T_ )
1081             typedef long long _off_t;
1082             typedef _off_t off_t;
1083 #           define _OFF_T_
1084 #       else
1085 #           ifdef off_t
1086 #               undef off_t
1087 #           endif
1088 #           define off_t long long
1089 #       endif
1090 #   endif
1091
1092 #   ifndef O_NONBLOCK
1093 #       define O_NONBLOCK 0
1094 #   endif
1095
1096 #   include <tchar.h>
1097 #endif /* _WIN32 */
1098
1099 typedef struct {
1100     unsigned num, den;
1101 } vlc_rational_t;
1102
1103 VLC_API bool vlc_ureduce( unsigned *, unsigned *, uint64_t, uint64_t, uint64_t );
1104
1105 #define container_of(ptr, type, member) \
1106     ((type *)(((char *)(ptr)) - offsetof(type, member)))
1107
1108 VLC_USED VLC_MALLOC
1109 static inline void *vlc_alloc(size_t count, size_t size)
1110 {
1111     return mul_overflow(count, size, &size) ? NULL : malloc(size);
1112 }
1113
1114 /*****************************************************************************
1115  * I18n stuff
1116  *****************************************************************************/
1117 VLC_API const char *vlc_gettext(const char *msgid) VLC_FORMAT_ARG(1);
1118 VLC_API const char *vlc_ngettext(const char *s, const char *p, unsigned long n)
1119 VLC_FORMAT_ARG(1) VLC_FORMAT_ARG(2);
1120
1121 #define vlc_pgettext( ctx, id ) \
1122         vlc_pgettext_aux( ctx "\004" id, id )
1123
1124 VLC_FORMAT_ARG(2)
1125 static inline const char *vlc_pgettext_aux( const char *ctx, const char *id )
1126 {
1127     const char *tr = vlc_gettext( ctx );
1128     return (tr == ctx) ? id : tr;
1129 }
1130
1131 /*****************************************************************************
1132  * Loosy memory allocation functions. Do not use in new code.
1133  *****************************************************************************/
1134 static inline void *xmalloc(size_t len)
1135 {
1136     void *ptr = malloc(len);
1137     if (unlikely(ptr == NULL && len > 0))
1138         abort();
1139     return ptr;
1140 }
1141
1142 static inline void *xrealloc(void *ptr, size_t len)
1143 {
1144     void *nptr = realloc(ptr, len);
1145     if (unlikely(nptr == NULL && len > 0))
1146         abort();
1147     return nptr;
1148 }
1149
1150 static inline void *xcalloc(size_t n, size_t size)
1151 {
1152     void *ptr = calloc(n, size);
1153     if (unlikely(ptr == NULL && (n > 0 || size > 0)))
1154         abort ();
1155     return ptr;
1156 }
1157
1158 static inline char *xstrdup (const char *str)
1159 {
1160     char *ptr = strdup (str);
1161     if (unlikely(ptr == NULL))
1162         abort ();
1163     return ptr;
1164 }
1165
1166 /*****************************************************************************
1167  * libvlc features
1168  *****************************************************************************/
1169 VLC_API const char * VLC_CompileBy( void ) VLC_USED;
1170 VLC_API const char * VLC_CompileHost( void ) VLC_USED;
1171 VLC_API const char * VLC_Compiler( void ) VLC_USED;
1172
1173 /*****************************************************************************
1174  * Additional vlc stuff
1175  *****************************************************************************/
1176 #include "vlc_messages.h"
1177 #include "vlc_objects.h"
1178 #include "vlc_variables.h"
1179 #include "vlc_configuration.h"
1180
1181 #if defined( _WIN32 ) || defined( __OS2__ )
1182 #   define DIR_SEP_CHAR '\\'
1183 #   define DIR_SEP "\\"
1184 #   define PATH_SEP_CHAR ';'
1185 #   define PATH_SEP ";"
1186 #else
1187 #   define DIR_SEP_CHAR '/'
1188 #   define DIR_SEP "/"
1189 #   define PATH_SEP_CHAR ':'
1190 #   define PATH_SEP ":"
1191 #endif
1192
1193 #define LICENSE_MSG \
1194   _("This program comes with NO WARRANTY, to the extent permitted by " \
1195     "law.\nYou may redistribute it under the terms of the GNU General " \
1196     "Public License;\nsee the file named COPYING for details.\n" \
1197     "Written by the VideoLAN team; see the AUTHORS file.\n")
1198
1199 #endif /* !VLC_COMMON_H */