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_list_t vlc_list_t;
 332 typedef struct vlc_object_t vlc_object_t;
 333 typedef struct libvlc_int_t libvlc_int_t;
 334 typedef struct date_t date_t;
 335
 336 /* Playlist */
 337
 338 typedef struct playlist_t playlist_t;
 339 typedef struct playlist_item_t playlist_item_t;
 340 typedef struct services_discovery_t services_discovery_t;
 341 typedef struct vlc_renderer_discovery_t vlc_renderer_discovery_t;
 342 typedef struct vlc_renderer_item_t vlc_renderer_item_t;
 343
 344 /* Modules */
 345 typedef struct module_t module_t;
 346 typedef struct module_config_t module_config_t;
 347
 348 typedef struct config_category_t config_category_t;
 349
 350 /* Input */
 351 typedef struct input_thread_t input_thread_t;
 352 typedef struct input_item_t input_item_t;
 353 typedef struct input_item_node_t input_item_node_t;
 354 typedef struct stream_t     stream_t;
 355 typedef struct stream_t demux_t;
 356 typedef struct es_out_t     es_out_t;
 357 typedef struct es_out_id_t  es_out_id_t;
 358 typedef struct seekpoint_t seekpoint_t;
 359 typedef struct info_t info_t;
 360 typedef struct info_category_t info_category_t;
 361 typedef struct input_attachment_t input_attachment_t;
 362
 363 /* Format */
 364 typedef struct audio_format_t audio_format_t;
 365 typedef struct video_format_t video_format_t;
 366 typedef struct subs_format_t subs_format_t;
 367 typedef struct es_format_t es_format_t;
 368 typedef struct video_palette_t video_palette_t;
 369
 370 /* Audio */
 371 typedef struct audio_output audio_output_t;
 372 typedef audio_format_t audio_sample_format_t;
 373
 374 /* Video */
 375 typedef struct vout_thread_t vout_thread_t;
 376 typedef struct vlc_viewpoint_t vlc_viewpoint_t;
 377
 378 typedef video_format_t video_frame_format_t;
 379 typedef struct picture_t picture_t;
 380
 381 /* Subpictures */
 382 typedef struct spu_t spu_t;
 383 typedef struct subpicture_t subpicture_t;
 384 typedef struct subpicture_region_t subpicture_region_t;
 385
 386 typedef struct image_handler_t image_handler_t;
 387
 388 /* Stream output */
 389 typedef struct sout_instance_t sout_instance_t;
 390
 391 typedef struct sout_input_t sout_input_t;
 392 typedef struct sout_packetizer_input_t sout_packetizer_input_t;
 393
 394 typedef struct sout_access_out_t sout_access_out_t;
 395
 396 typedef struct sout_mux_t sout_mux_t;
 397
 398 typedef struct sout_stream_t    sout_stream_t;
 399
 400 typedef struct config_chain_t       config_chain_t;
 401 typedef struct session_descriptor_t session_descriptor_t;
 402
 403 /* Decoders */
 404 typedef struct decoder_t         decoder_t;
 405 typedef struct decoder_synchro_t decoder_synchro_t;
 406
 407 /* Encoders */
 408 typedef struct encoder_t      encoder_t;
 409
 410 /* Filters */
 411 typedef struct filter_t filter_t;
 412
 413 /* Network */
 414 typedef struct vlc_url_t vlc_url_t;
 415
 416 /* Misc */
 417 typedef struct iso639_lang_t iso639_lang_t;
 418
 419 /* block */
 420 typedef struct block_t      block_t;
 421 typedef struct block_fifo_t block_fifo_t;
 422
 423 /* Hashing */
 424 typedef struct md5_s md5_t;
 425
 426 /* XML */
 427 typedef struct xml_t xml_t;
 428 typedef struct xml_reader_t xml_reader_t;
 429
 430 /* vod server */
 431 typedef struct vod_t     vod_t;
 432 typedef struct vod_media_t vod_media_t;
 433
 434 /* VLM */
 435 typedef struct vlm_t         vlm_t;
 436 typedef struct vlm_message_t vlm_message_t;
 437
 438 /* misc */
 439 typedef struct vlc_meta_t    vlc_meta_t;
 440 typedef struct input_stats_t input_stats_t;
 441 typedef struct addon_entry_t addon_entry_t;
 442
 443 /* Update */
 444 typedef struct update_t update_t;
 445
 446 /**
 447  * VLC value structure
 448  */
 449 typedef union
 450 {
 451     int64_t         i_int;
 452     bool            b_bool;
 453     float           f_float;
 454     char *          psz_string;
 455     void *          p_address;
 456     vlc_list_t *    p_list;
 457     struct { int32_t x; int32_t y; } coords;
 458
 459 } vlc_value_t;
 460
 461 /**
 462  * VLC list structure
 463  */
 464 struct vlc_list_t
 465 {
 466     int          i_type;
 467     int          i_count;
 468     vlc_value_t *p_values;
 469 };
 470
 471 /*****************************************************************************
 472  * Error values (shouldn't be exposed)
 473  *****************************************************************************/
 474 #define VLC_SUCCESS        (-0) /**< No error */
 475 #define VLC_EGENERIC       (-1) /**< Unspecified error */
 476 #define VLC_ENOMEM         (-2) /**< Not enough memory */
 477 #define VLC_ETIMEOUT       (-3) /**< Timeout */
 478 #define VLC_ENOMOD         (-4) /**< Module not found */
 479 #define VLC_ENOOBJ         (-5) /**< Object not found */
 480 #define VLC_ENOVAR         (-6) /**< Variable not found */
 481 #define VLC_EBADVAR        (-7) /**< Bad variable value */
 482 #define VLC_ENOITEM        (-8) /**< Item not found */
 483
 484 /*****************************************************************************
 485  * Variable callbacks: called when the value is modified
 486  *****************************************************************************/
 487 typedef int ( * vlc_callback_t ) ( vlc_object_t *,      /* variable's object */
 488                                    char const *,            /* variable name */
 489                                    vlc_value_t,                 /* old value */
 490                                    vlc_value_t,                 /* new value */
 491                                    void * );                /* callback data */
 492
 493 /*****************************************************************************
 494  * List callbacks: called when elements are added/removed from the list
 495  *****************************************************************************/
 496 typedef int ( * vlc_list_callback_t ) ( vlc_object_t *,      /* variable's object */
 497                                         char const *,            /* variable name */
 498                                         int,                  /* VLC_VAR_* action */
 499                                         vlc_value_t *,      /* new/deleted value  */
 500                                         void *);                 /* callback data */
 501
 502 /*****************************************************************************
 503  * OS-specific headers and thread types
 504  *****************************************************************************/
 505 #if defined( _WIN32 )
 506 #   include <malloc.h>
 507 #   ifndef PATH_MAX
 508 #       define PATH_MAX MAX_PATH
 509 #   endif
 510 #   include <windows.h>
 511 #endif
 512
 513 #ifdef __APPLE__
 514 #include <sys/syslimits.h>
 515 #include <AvailabilityMacros.h>
 516 #endif
 517
 518 #ifdef __OS2__
 519 #   define OS2EMX_PLAIN_CHAR
 520 #   define INCL_BASE
 521 #   define INCL_PM
 522 #   include <os2safe.h>
 523 #   include <os2.h>
 524 #endif
 525
 526 #include "vlc_mtime.h"
 527 #include "vlc_threads.h"
 528
 529 /**
 530  * \defgroup intops Integer operations
 531  * \ingroup cext
 532  *
 533  * Common integer functions.
 534  * @{
 535  */
 536 /* __MAX and __MIN: self explanatory */
 537 #ifndef __MAX
 538 #   define __MAX(a, b)   ( ((a) > (b)) ? (a) : (b) )
 539 #endif
 540 #ifndef __MIN
 541 #   define __MIN(a, b)   ( ((a) < (b)) ? (a) : (b) )
 542 #endif
 543
 544 /* clip v in [min, max] */
 545 #define VLC_CLIP(v, min, max)    __MIN(__MAX((v), (min)), (max))
 546
 547 /** Greatest common divisor */
 548 VLC_USED
 549 static inline int64_t GCD ( int64_t a, int64_t b )
 550 {
 551     while( b )
 552     {
 553         int64_t c = a % b;
 554         a = b;
 555         b = c;
 556     }
 557     return a;
 558 }
 559
 560 /* function imported from libavutil/common.h */
 561 VLC_USED
 562 static inline uint8_t clip_uint8_vlc( int32_t a )
 563 {
 564     if( a&(~255) ) return (-a)>>31;
 565     else           return a;
 566 }
 567
 568 /**
 569  * \defgroup bitops Bit operations
 570  * @{
 571  */
 572
 573 #define VLC_INT_FUNC(basename) \
 574         VLC_INT_FUNC_TYPE(basename, unsigned, ) \
 575         VLC_INT_FUNC_TYPE(basename, unsigned long, l) \
 576         VLC_INT_FUNC_TYPE(basename, unsigned long long, ll)
 577
 578 #if defined (__GNUC__) || defined (__clang__)
 579 # define VLC_INT_FUNC_TYPE(basename,type,suffix) \
 580 VLC_USED static inline int vlc_##basename##suffix(type x) \
 581 { \
 582     return __builtin_##basename##suffix(x); \
 583 }
 584
 585 VLC_INT_FUNC(clz)
 586 #else
 587 VLC_USED static inline int vlc_clzll(unsigned long long x)
 588 {
 589     int i = sizeof (x) * 8;
 590
 591     while (x)
 592     {
 593         x >>= 1;
 594         i--;
 595     }
 596     return i;
 597 }
 598
 599 VLC_USED static inline int vlc_clzl(unsigned long x)
 600 {
 601     return vlc_clzll(x) - ((sizeof (long long) - sizeof (long)) * 8);
 602 }
 603
 604 VLC_USED static inline int vlc_clz(unsigned x)
 605 {
 606     return vlc_clzll(x) - ((sizeof (long long) - sizeof (int)) * 8);
 607 }
 608
 609 VLC_USED static inline int vlc_ctz_generic(unsigned long long x)
 610 {
 611     unsigned i = sizeof (x) * 8;
 612
 613     while (x)
 614     {
 615         x <<= 1;
 616         i--;
 617     }
 618     return i;
 619 }
 620
 621 VLC_USED static inline int vlc_parity_generic(unsigned long long x)
 622 {
 623     for (unsigned i = 4 * sizeof (x); i > 0; i /= 2)
 624         x ^= x >> i;
 625     return x & 1;
 626 }
 627
 628 VLC_USED static inline int vlc_popcount_generic(unsigned long long x)
 629 {
 630     int count = 0;
 631     while (x)
 632     {
 633         count += x & 1;
 634         x = x >> 1;
 635     }
 636     return count;
 637 }
 638
 639 # define VLC_INT_FUNC_TYPE(basename,type,suffix) \
 640 VLC_USED static inline int vlc_##basename##suffix(type x) \
 641 { \
 642     return vlc_##basename##_generic(x); \
 643 }
 644 #endif
 645
 646 VLC_INT_FUNC(ctz)
 647 VLC_INT_FUNC(parity)
 648 VLC_INT_FUNC(popcount)
 649
 650 #ifndef __cplusplus
 651 # define VLC_INT_GENERIC(func,x) \
 652     _Generic((x), \
 653         unsigned char:      func(x), \
 654           signed char:      func(x), \
 655         unsigned short:     func(x), \
 656           signed short:     func(x), \
 657         unsigned int:       func(x), \
 658           signed int:       func(x), \
 659         unsigned long:      func##l(x), \
 660           signed long:      func##l(x), \
 661         unsigned long long: func##ll(x), \
 662           signed long long: func##ll(x))
 663
 664 /**
 665  * Count leading zeroes
 666  *
 667  * This function counts the number of consecutive zero (clear) bits
 668  * down from the highest order bit in an unsigned integer.
 669  *
 670  * \param x a non-zero integer
 671  * \note This macro assumes that CHAR_BIT equals 8.
 672  * \warning By definition, the result depends on the (width of the) type of x.
 673  * \return The number of leading zero bits in x.
 674  */
 675 # define clz(x) \
 676     _Generic((x), \
 677         unsigned char: (vlc_clz(x) - (sizeof (unsigned) - 1) * 8), \
 678         unsigned short: (vlc_clz(x) \
 679                 - (sizeof (unsigned) - sizeof (unsigned short)) * 8), \
 680         unsigned: vlc_clz(x), \
 681         unsigned long: vlc_clzl(x), \
 682         unsigned long long: vlc_clzll(x))
 683
 684 /**
 685  * Count trailing zeroes
 686  *
 687  * This function counts the number of consecutive zero bits
 688  * up from the lowest order bit in an unsigned integer.
 689  *
 690  * \param x a non-zero integer
 691  * \note This function assumes that CHAR_BIT equals 8.
 692  * \return The number of trailing zero bits in x.
 693  */
 694 # define ctz(x) VLC_INT_GENERIC(vlc_ctz, x)
 695
 696 /**
 697  * Parity
 698  *
 699  * This function determines the parity of an integer.
 700  * \retval 0 if x has an even number of set bits.
 701  * \retval 1 if x has an odd number of set bits.
 702  */
 703 # define parity(x) VLC_INT_GENERIC(vlc_parity, x)
 704
 705 /**
 706  * Bit weight / population count
 707  *
 708  * This function counts the number of non-zero bits in an integer.
 709  *
 710  * \return The count of non-zero bits.
 711  */
 712 # define vlc_popcount(x) \
 713     _Generic((x), \
 714         signed char:  vlc_popcount((unsigned char)(x)), \
 715         signed short: vlc_popcount((unsigned short)(x)), \
 716         default: VLC_INT_GENERIC(vlc_popcount ,x))
 717 #else
 718 VLC_USED static inline int vlc_popcount(unsigned char x)
 719 {
 720     return vlc_popcount((unsigned)x);
 721 }
 722
 723 VLC_USED static inline int vlc_popcount(unsigned short x)
 724 {
 725     return vlc_popcount((unsigned)x);
 726 }
 727
 728 VLC_USED static inline int vlc_popcount(unsigned long x)
 729 {
 730     return vlc_popcountl(x);
 731 }
 732
 733 VLC_USED static inline int vlc_popcount(unsigned long long x)
 734 {
 735     return vlc_popcountll(x);
 736 }
 737 #endif
 738
 739 /** Byte swap (16 bits) */
 740 VLC_USED
 741 static inline uint16_t vlc_bswap16(uint16_t x)
 742 {
 743     return (x << 8) | (x >> 8);
 744 }
 745
 746 /** Byte swap (32 bits) */
 747 VLC_USED
 748 static inline uint32_t vlc_bswap32(uint32_t x)
 749 {
 750 #if defined (__GNUC__) || defined(__clang__)
 751     return __builtin_bswap32 (x);
 752 #else
 753     return ((x & 0x000000FF) << 24)
 754          | ((x & 0x0000FF00) <<  8)
 755          | ((x & 0x00FF0000) >>  8)
 756          | ((x & 0xFF000000) >> 24);
 757 #endif
 758 }
 759
 760 /** Byte swap (64 bits) */
 761 VLC_USED
 762 static inline uint64_t vlc_bswap64(uint64_t x)
 763 {
 764 #if defined (__GNUC__) || defined(__clang__)
 765     return __builtin_bswap64 (x);
 766 #elif !defined (__cplusplus)
 767     return ((x & 0x00000000000000FF) << 56)
 768          | ((x & 0x000000000000FF00) << 40)
 769          | ((x & 0x0000000000FF0000) << 24)
 770          | ((x & 0x00000000FF000000) <<  8)
 771          | ((x & 0x000000FF00000000) >>  8)
 772          | ((x & 0x0000FF0000000000) >> 24)
 773          | ((x & 0x00FF000000000000) >> 40)
 774          | ((x & 0xFF00000000000000) >> 56);
 775 #else
 776     return ((x & 0x00000000000000FFULL) << 56)
 777          | ((x & 0x000000000000FF00ULL) << 40)
 778          | ((x & 0x0000000000FF0000ULL) << 24)
 779          | ((x & 0x00000000FF000000ULL) <<  8)
 780          | ((x & 0x000000FF00000000ULL) >>  8)
 781          | ((x & 0x0000FF0000000000ULL) >> 24)
 782          | ((x & 0x00FF000000000000ULL) >> 40)
 783          | ((x & 0xFF00000000000000ULL) >> 56);
 784 #endif
 785 }
 786 /** @} */
 787
 788 /**
 789  * \defgroup overflow Overflowing arithmetic
 790  * @{
 791  */
 792 static inline bool uadd_overflow(unsigned a, unsigned b, unsigned *res)
 793 {
 794 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 795      return __builtin_uadd_overflow(a, b, res);
 796 #else
 797      *res = a + b;
 798      return (a + b) < a;
 799 #endif
 800 }
 801
 802 static inline bool uaddl_overflow(unsigned long a, unsigned long b,
 803                                   unsigned long *res)
 804 {
 805 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 806      return __builtin_uaddl_overflow(a, b, res);
 807 #else
 808      *res = a + b;
 809      return (a + b) < a;
 810 #endif
 811 }
 812
 813 static inline bool uaddll_overflow(unsigned long long a, unsigned long long b,
 814                                    unsigned long long *res)
 815 {
 816 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 817      return __builtin_uaddll_overflow(a, b, res);
 818 #else
 819      *res = a + b;
 820      return (a + b) < a;
 821 #endif
 822 }
 823
 824 #ifndef __cplusplus
 825 /**
 826  * Overflowing addition
 827  *
 828  * Converts \p a and \p b to the type of \p *r.
 829  * Then computes the sum of both conversions while checking for overflow.
 830  * Finally stores the result in \p *r.
 831  *
 832  * \param a an integer
 833  * \param b an integer
 834  * \param r a pointer to an integer [OUT]
 835  * \retval false The sum did not overflow.
 836  * \retval true The sum overflowed.
 837  */
 838 # define add_overflow(a,b,r) \
 839     _Generic(*(r), \
 840         unsigned: uadd_overflow(a, b, (unsigned *)(r)), \
 841         unsigned long: uaddl_overflow(a, b, (unsigned long *)(r)), \
 842         unsigned long long: uaddll_overflow(a, b, (unsigned long long *)(r)))
 843 #else
 844 static inline bool add_overflow(unsigned a, unsigned b, unsigned *res)
 845 {
 846     return uadd_overflow(a, b, res);
 847 }
 848
 849 static inline bool add_overflow(unsigned long a, unsigned long b,
 850                                 unsigned long *res)
 851 {
 852     return uaddl_overflow(a, b, res);
 853 }
 854
 855 static inline bool add_overflow(unsigned long long a, unsigned long long b,
 856                                 unsigned long long *res)
 857 {
 858     return uaddll_overflow(a, b, res);
 859 }
 860 #endif
 861
 862 #if !(VLC_GCC_VERSION(5,0) || defined(__clang__))
 863 # include <limits.h>
 864 #endif
 865
 866 static inline bool umul_overflow(unsigned a, unsigned b, unsigned *res)
 867 {
 868 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 869      return __builtin_umul_overflow(a, b, res);
 870 #else
 871      *res = a * b;
 872      return b > 0 && a > (UINT_MAX / b);
 873 #endif
 874 }
 875
 876 static inline bool umull_overflow(unsigned long a, unsigned long b,
 877                                   unsigned long *res)
 878 {
 879 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 880      return __builtin_umull_overflow(a, b, res);
 881 #else
 882      *res = a * b;
 883      return b > 0 && a > (ULONG_MAX / b);
 884 #endif
 885 }
 886
 887 static inline bool umulll_overflow(unsigned long long a, unsigned long long b,
 888                                    unsigned long long *res)
 889 {
 890 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 891      return __builtin_umulll_overflow(a, b, res);
 892 #else
 893      *res = a * b;
 894      return b > 0 && a > (ULLONG_MAX / b);
 895 #endif
 896 }
 897
 898 #ifndef __cplusplus
 899 /**
 900  * Overflowing multiplication
 901  *
 902  * Converts \p a and \p b to the type of \p *r.
 903  * Then computes the product of both conversions while checking for overflow.
 904  * Finally stores the result in \p *r.
 905  *
 906  * \param a an integer
 907  * \param b an integer
 908  * \param r a pointer to an integer [OUT]
 909  * \retval false The product did not overflow.
 910  * \retval true The product overflowed.
 911  */
 912 #define mul_overflow(a,b,r) \
 913     _Generic(*(r), \
 914         unsigned: umul_overflow(a, b, (unsigned *)(r)), \
 915         unsigned long: umull_overflow(a, b, (unsigned long *)(r)), \
 916         unsigned long long: umulll_overflow(a, b, (unsigned long long *)(r)))
 917 #else
 918 static inline bool mul_overflow(unsigned a, unsigned b, unsigned *res)
 919 {
 920     return umul_overflow(a, b, res);
 921 }
 922
 923 static inline bool mul_overflow(unsigned long a, unsigned long b,
 924                                 unsigned long *res)
 925 {
 926     return umull_overflow(a, b, res);
 927 }
 928
 929 static inline bool mul_overflow(unsigned long long a, unsigned long long b,
 930                                 unsigned long long *res)
 931 {
 932     return umulll_overflow(a, b, res);
 933 }
 934 #endif
 935 /** @} */
 936 /** @} */
 937
 938 /* Free and set set the variable to NULL */
 939 #define FREENULL(a) do { free( a ); a = NULL; } while(0)
 940
 941 #define EMPTY_STR(str) (!str || !*str)
 942
 943 VLC_API char const * vlc_error( int ) VLC_USED;
 944
 945 #include <vlc_arrays.h>
 946
 947 /* MSB (big endian)/LSB (little endian) conversions - network order is always
 948  * MSB, and should be used for both network communications and files. */
 949
 950 #ifdef WORDS_BIGENDIAN
 951 # define hton16(i) ((uint16_t)(i))
 952 # define hton32(i) ((uint32_t)(i))
 953 # define hton64(i) ((uint64_t)(i))
 954 #else
 955 # define hton16(i) vlc_bswap16(i)
 956 # define hton32(i) vlc_bswap32(i)
 957 # define hton64(i) vlc_bswap64(i)
 958 #endif
 959 #define ntoh16(i) hton16(i)
 960 #define ntoh32(i) hton32(i)
 961 #define ntoh64(i) hton64(i)
 962
 963 /** Reads 16 bits in network byte order */
 964 VLC_USED
 965 static inline uint16_t U16_AT (const void *p)
 966 {
 967     uint16_t x;
 968
 969     memcpy (&x, p, sizeof (x));
 970     return ntoh16 (x);
 971 }
 972
 973 /** Reads 32 bits in network byte order */
 974 VLC_USED
 975 static inline uint32_t U32_AT (const void *p)
 976 {
 977     uint32_t x;
 978
 979     memcpy (&x, p, sizeof (x));
 980     return ntoh32 (x);
 981 }
 982
 983 /** Reads 64 bits in network byte order */
 984 VLC_USED
 985 static inline uint64_t U64_AT (const void *p)
 986 {
 987     uint64_t x;
 988
 989     memcpy (&x, p, sizeof (x));
 990     return ntoh64 (x);
 991 }
 992
 993 #define GetWBE(p)  U16_AT(p)
 994 #define GetDWBE(p) U32_AT(p)
 995 #define GetQWBE(p) U64_AT(p)
 996
 997 /** Reads 16 bits in little-endian order */
 998 VLC_USED
 999 static inline uint16_t GetWLE (const void *p)
1000 {
1001     uint16_t x;
1002
1003     memcpy (&x, p, sizeof (x));
1004 #ifdef WORDS_BIGENDIAN
1005     x = vlc_bswap16 (x);
1006 #endif
1007     return x;
1008 }
1009
1010 /** Reads 32 bits in little-endian order */
1011 VLC_USED
1012 static inline uint32_t GetDWLE (const void *p)
1013 {
1014     uint32_t x;
1015
1016     memcpy (&x, p, sizeof (x));
1017 #ifdef WORDS_BIGENDIAN
1018     x = vlc_bswap32 (x);
1019 #endif
1020     return x;
1021 }
1022
1023 /** Reads 64 bits in little-endian order */
1024 VLC_USED
1025 static inline uint64_t GetQWLE (const void *p)
1026 {
1027     uint64_t x;
1028
1029     memcpy (&x, p, sizeof (x));
1030 #ifdef WORDS_BIGENDIAN
1031     x = vlc_bswap64 (x);
1032 #endif
1033     return x;
1034 }
1035
1036 /** Writes 16 bits in network byte order */
1037 static inline void SetWBE (void *p, uint16_t w)
1038 {
1039     w = hton16 (w);
1040     memcpy (p, &w, sizeof (w));
1041 }
1042
1043 /** Writes 32 bits in network byte order */
1044 static inline void SetDWBE (void *p, uint32_t dw)
1045 {
1046     dw = hton32 (dw);
1047     memcpy (p, &dw, sizeof (dw));
1048 }
1049
1050 /** Writes 64 bits in network byte order */
1051 static inline void SetQWBE (void *p, uint64_t qw)
1052 {
1053     qw = hton64 (qw);
1054     memcpy (p, &qw, sizeof (qw));
1055 }
1056
1057 /** Writes 16 bits in little endian order */
1058 static inline void SetWLE (void *p, uint16_t w)
1059 {
1060 #ifdef WORDS_BIGENDIAN
1061     w = vlc_bswap16 (w);
1062 #endif
1063     memcpy (p, &w, sizeof (w));
1064 }
1065
1066 /** Writes 32 bits in little endian order */
1067 static inline void SetDWLE (void *p, uint32_t dw)
1068 {
1069 #ifdef WORDS_BIGENDIAN
1070     dw = vlc_bswap32 (dw);
1071 #endif
1072     memcpy (p, &dw, sizeof (dw));
1073 }
1074
1075 /** Writes 64 bits in little endian order */
1076 static inline void SetQWLE (void *p, uint64_t qw)
1077 {
1078 #ifdef WORDS_BIGENDIAN
1079     qw = vlc_bswap64 (qw);
1080 #endif
1081     memcpy (p, &qw, sizeof (qw));
1082 }
1083
1084 /* */
1085 #define VLC_UNUSED(x) (void)(x)
1086
1087 /* Stuff defined in src/extras/libc.c */
1088
1089 #if defined(_WIN32)
1090 /* several type definitions */
1091 #   if defined( __MINGW32__ )
1092 #       if !defined( _OFF_T_ )
1093             typedef long long _off_t;
1094             typedef _off_t off_t;
1095 #           define _OFF_T_
1096 #       else
1097 #           ifdef off_t
1098 #               undef off_t
1099 #           endif
1100 #           define off_t long long
1101 #       endif
1102 #   endif
1103
1104 #   ifndef O_NONBLOCK
1105 #       define O_NONBLOCK 0
1106 #   endif
1107
1108 #   include <tchar.h>
1109 #endif /* _WIN32 */
1110
1111 typedef struct {
1112     unsigned num, den;
1113 } vlc_rational_t;
1114
1115 VLC_API bool vlc_ureduce( unsigned *, unsigned *, uint64_t, uint64_t, uint64_t );
1116
1117 #define container_of(ptr, type, member) \
1118     ((type *)(((char *)(ptr)) - offsetof(type, member)))
1119
1120 VLC_USED VLC_MALLOC
1121 static inline void *vlc_alloc(size_t count, size_t size)
1122 {
1123     return mul_overflow(count, size, &size) ? NULL : malloc(size);
1124 }
1125
1126 /*****************************************************************************
1127  * I18n stuff
1128  *****************************************************************************/
1129 VLC_API char *vlc_gettext( const char *msgid ) VLC_FORMAT_ARG(1);
1130 VLC_API char *vlc_ngettext( const char *s, const char *p, unsigned long n ) VLC_FORMAT_ARG(1) VLC_FORMAT_ARG(2);
1131
1132 #define vlc_pgettext( ctx, id ) \
1133         vlc_pgettext_aux( ctx "\004" id, id )
1134
1135 VLC_FORMAT_ARG(2)
1136 static inline const char *vlc_pgettext_aux( const char *ctx, const char *id )
1137 {
1138     const char *tr = vlc_gettext( ctx );
1139     return (tr == ctx) ? id : tr;
1140 }
1141
1142 /*****************************************************************************
1143  * Loosy memory allocation functions. Do not use in new code.
1144  *****************************************************************************/
1145 static inline void *xmalloc(size_t len)
1146 {
1147     void *ptr = malloc(len);
1148     if (unlikely(ptr == NULL && len > 0))
1149         abort();
1150     return ptr;
1151 }
1152
1153 static inline void *xrealloc(void *ptr, size_t len)
1154 {
1155     void *nptr = realloc(ptr, len);
1156     if (unlikely(nptr == NULL && len > 0))
1157         abort();
1158     return nptr;
1159 }
1160
1161 static inline void *xcalloc(size_t n, size_t size)
1162 {
1163     void *ptr = calloc(n, size);
1164     if (unlikely(ptr == NULL && (n > 0 || size > 0)))
1165         abort ();
1166     return ptr;
1167 }
1168
1169 static inline char *xstrdup (const char *str)
1170 {
1171     char *ptr = strdup (str);
1172     if (unlikely(ptr == NULL))
1173         abort ();
1174     return ptr;
1175 }
1176
1177 /*****************************************************************************
1178  * libvlc features
1179  *****************************************************************************/
1180 VLC_API const char * VLC_CompileBy( void ) VLC_USED;
1181 VLC_API const char * VLC_CompileHost( void ) VLC_USED;
1182 VLC_API const char * VLC_Compiler( void ) VLC_USED;
1183
1184 /*****************************************************************************
1185  * Additional vlc stuff
1186  *****************************************************************************/
1187 #include "vlc_messages.h"
1188 #include "vlc_objects.h"
1189 #include "vlc_variables.h"
1190 #include "vlc_configuration.h"
1191
1192 #if defined( _WIN32 ) || defined( __OS2__ )
1193 #   define DIR_SEP_CHAR '\\'
1194 #   define DIR_SEP "\\"
1195 #   define PATH_SEP_CHAR ';'
1196 #   define PATH_SEP ";"
1197 #else
1198 #   define DIR_SEP_CHAR '/'
1199 #   define DIR_SEP "/"
1200 #   define PATH_SEP_CHAR ':'
1201 #   define PATH_SEP ":"
1202 #endif
1203
1204 #define LICENSE_MSG \
1205   _("This program comes with NO WARRANTY, to the extent permitted by " \
1206     "law.\nYou may redistribute it under the terms of the GNU General " \
1207     "Public License;\nsee the file named COPYING for details.\n" \
1208     "Written by the VideoLAN team; see the AUTHORS file.\n")
1209
1210 #endif /* !VLC_COMMON_H */