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 services_discovery_sys_t services_discovery_sys_t;
 342 typedef struct vlc_renderer_discovery_t vlc_renderer_discovery_t;
 343 typedef struct vlc_renderer_item_t vlc_renderer_item_t;
 344
 345 /* Modules */
 346 typedef struct module_t module_t;
 347 typedef struct module_config_t module_config_t;
 348
 349 typedef struct config_category_t config_category_t;
 350
 351 /* Input */
 352 typedef struct input_thread_t input_thread_t;
 353 typedef struct input_item_t input_item_t;
 354 typedef struct input_item_node_t input_item_node_t;
 355 typedef struct access_sys_t access_sys_t;
 356 typedef struct stream_t     stream_t;
 357 typedef struct stream_sys_t stream_sys_t;
 358 typedef struct stream_t demux_t;
 359 typedef struct demux_sys_t demux_sys_t;
 360 typedef struct es_out_t     es_out_t;
 361 typedef struct es_out_id_t  es_out_id_t;
 362 typedef struct es_out_sys_t es_out_sys_t;
 363 typedef struct seekpoint_t seekpoint_t;
 364 typedef struct info_t info_t;
 365 typedef struct info_category_t info_category_t;
 366 typedef struct input_attachment_t input_attachment_t;
 367
 368 /* Format */
 369 typedef struct audio_format_t audio_format_t;
 370 typedef struct video_format_t video_format_t;
 371 typedef struct subs_format_t subs_format_t;
 372 typedef struct es_format_t es_format_t;
 373 typedef struct video_palette_t video_palette_t;
 374
 375 /* Audio */
 376 typedef struct audio_output audio_output_t;
 377 typedef struct aout_sys_t aout_sys_t;
 378 typedef audio_format_t audio_sample_format_t;
 379
 380 /* Video */
 381 typedef struct vout_thread_t vout_thread_t;
 382 typedef struct vlc_viewpoint_t vlc_viewpoint_t;
 383
 384 typedef video_format_t video_frame_format_t;
 385 typedef struct picture_t picture_t;
 386 typedef struct picture_sys_t picture_sys_t;
 387
 388 /* Subpictures */
 389 typedef struct spu_t spu_t;
 390 typedef struct subpicture_t subpicture_t;
 391 typedef struct subpicture_region_t subpicture_region_t;
 392
 393 typedef struct image_handler_t image_handler_t;
 394
 395 /* Stream output */
 396 typedef struct sout_instance_t sout_instance_t;
 397
 398 typedef struct sout_input_t sout_input_t;
 399 typedef struct sout_packetizer_input_t sout_packetizer_input_t;
 400
 401 typedef struct sout_access_out_t sout_access_out_t;
 402 typedef struct sout_access_out_sys_t   sout_access_out_sys_t;
 403
 404 typedef struct sout_mux_t sout_mux_t;
 405 typedef struct sout_mux_sys_t sout_mux_sys_t;
 406
 407 typedef struct sout_stream_t    sout_stream_t;
 408 typedef struct sout_stream_sys_t sout_stream_sys_t;
 409
 410 typedef struct config_chain_t       config_chain_t;
 411 typedef struct session_descriptor_t session_descriptor_t;
 412
 413 /* Decoders */
 414 typedef struct decoder_t         decoder_t;
 415 typedef struct decoder_sys_t     decoder_sys_t;
 416 typedef struct decoder_synchro_t decoder_synchro_t;
 417
 418 /* Encoders */
 419 typedef struct encoder_t      encoder_t;
 420 typedef struct encoder_sys_t  encoder_sys_t;
 421
 422 /* Filters */
 423 typedef struct filter_t filter_t;
 424 typedef struct filter_sys_t filter_sys_t;
 425
 426 /* Network */
 427 typedef struct vlc_url_t vlc_url_t;
 428
 429 /* Misc */
 430 typedef struct iso639_lang_t iso639_lang_t;
 431
 432 /* block */
 433 typedef struct block_t      block_t;
 434 typedef struct block_fifo_t block_fifo_t;
 435
 436 /* Hashing */
 437 typedef struct md5_s md5_t;
 438
 439 /* XML */
 440 typedef struct xml_t xml_t;
 441 typedef struct xml_sys_t xml_sys_t;
 442 typedef struct xml_reader_t xml_reader_t;
 443 typedef struct xml_reader_sys_t xml_reader_sys_t;
 444
 445 /* vod server */
 446 typedef struct vod_t     vod_t;
 447 typedef struct vod_sys_t vod_sys_t;
 448 typedef struct vod_media_t vod_media_t;
 449
 450 /* VLM */
 451 typedef struct vlm_t         vlm_t;
 452 typedef struct vlm_message_t vlm_message_t;
 453
 454 /* misc */
 455 typedef struct vlc_meta_t    vlc_meta_t;
 456 typedef struct input_stats_t input_stats_t;
 457 typedef struct addon_entry_t addon_entry_t;
 458
 459 /* Update */
 460 typedef struct update_t update_t;
 461
 462 /**
 463  * VLC value structure
 464  */
 465 typedef union
 466 {
 467     int64_t         i_int;
 468     bool            b_bool;
 469     float           f_float;
 470     char *          psz_string;
 471     void *          p_address;
 472     vlc_list_t *    p_list;
 473     struct { int32_t x; int32_t y; } coords;
 474
 475 } vlc_value_t;
 476
 477 /**
 478  * VLC list structure
 479  */
 480 struct vlc_list_t
 481 {
 482     int          i_type;
 483     int          i_count;
 484     vlc_value_t *p_values;
 485 };
 486
 487 /*****************************************************************************
 488  * Error values (shouldn't be exposed)
 489  *****************************************************************************/
 490 #define VLC_SUCCESS        (-0) /**< No error */
 491 #define VLC_EGENERIC       (-1) /**< Unspecified error */
 492 #define VLC_ENOMEM         (-2) /**< Not enough memory */
 493 #define VLC_ETIMEOUT       (-3) /**< Timeout */
 494 #define VLC_ENOMOD         (-4) /**< Module not found */
 495 #define VLC_ENOOBJ         (-5) /**< Object not found */
 496 #define VLC_ENOVAR         (-6) /**< Variable not found */
 497 #define VLC_EBADVAR        (-7) /**< Bad variable value */
 498 #define VLC_ENOITEM        (-8) /**< Item not found */
 499
 500 /*****************************************************************************
 501  * Variable callbacks: called when the value is modified
 502  *****************************************************************************/
 503 typedef int ( * vlc_callback_t ) ( vlc_object_t *,      /* variable's object */
 504                                    char const *,            /* variable name */
 505                                    vlc_value_t,                 /* old value */
 506                                    vlc_value_t,                 /* new value */
 507                                    void * );                /* callback data */
 508
 509 /*****************************************************************************
 510  * List callbacks: called when elements are added/removed from the list
 511  *****************************************************************************/
 512 typedef int ( * vlc_list_callback_t ) ( vlc_object_t *,      /* variable's object */
 513                                         char const *,            /* variable name */
 514                                         int,                  /* VLC_VAR_* action */
 515                                         vlc_value_t *,      /* new/deleted value  */
 516                                         void *);                 /* callback data */
 517
 518 /*****************************************************************************
 519  * OS-specific headers and thread types
 520  *****************************************************************************/
 521 #if defined( _WIN32 )
 522 #   include <malloc.h>
 523 #   ifndef PATH_MAX
 524 #       define PATH_MAX MAX_PATH
 525 #   endif
 526 #   include <windows.h>
 527 #endif
 528
 529 #ifdef __APPLE__
 530 #include <sys/syslimits.h>
 531 #include <AvailabilityMacros.h>
 532 #endif
 533
 534 #ifdef __OS2__
 535 #   define OS2EMX_PLAIN_CHAR
 536 #   define INCL_BASE
 537 #   define INCL_PM
 538 #   include <os2safe.h>
 539 #   include <os2.h>
 540 #endif
 541
 542 #include "vlc_mtime.h"
 543 #include "vlc_threads.h"
 544
 545 /**
 546  * \defgroup intops Integer operations
 547  * \ingroup cext
 548  *
 549  * Common integer functions.
 550  * @{
 551  */
 552 /* __MAX and __MIN: self explanatory */
 553 #ifndef __MAX
 554 #   define __MAX(a, b)   ( ((a) > (b)) ? (a) : (b) )
 555 #endif
 556 #ifndef __MIN
 557 #   define __MIN(a, b)   ( ((a) < (b)) ? (a) : (b) )
 558 #endif
 559
 560 /* clip v in [min, max] */
 561 #define VLC_CLIP(v, min, max)    __MIN(__MAX((v), (min)), (max))
 562
 563 /** Greatest common divisor */
 564 VLC_USED
 565 static inline int64_t GCD ( int64_t a, int64_t b )
 566 {
 567     while( b )
 568     {
 569         int64_t c = a % b;
 570         a = b;
 571         b = c;
 572     }
 573     return a;
 574 }
 575
 576 /* function imported from libavutil/common.h */
 577 VLC_USED
 578 static inline uint8_t clip_uint8_vlc( int32_t a )
 579 {
 580     if( a&(~255) ) return (-a)>>31;
 581     else           return a;
 582 }
 583
 584 /**
 585  * \defgroup bitops Bit operations
 586  * @{
 587  */
 588
 589 #define VLC_INT_FUNC(basename) \
 590         VLC_INT_FUNC_TYPE(basename, unsigned, ) \
 591         VLC_INT_FUNC_TYPE(basename, unsigned long, l) \
 592         VLC_INT_FUNC_TYPE(basename, unsigned long long, ll)
 593
 594 #if defined (__GNUC__) || defined (__clang__)
 595 # define VLC_INT_FUNC_TYPE(basename,type,suffix) \
 596 VLC_USED static inline int vlc_##basename##suffix(type x) \
 597 { \
 598     return __builtin_##basename##suffix(x); \
 599 }
 600
 601 VLC_INT_FUNC(clz)
 602 #else
 603 VLC_USED static inline int vlc_clzll(unsigned long long x)
 604 {
 605     int i = sizeof (x) * 8;
 606
 607     while (x)
 608     {
 609         x >>= 1;
 610         i--;
 611     }
 612     return i;
 613 }
 614
 615 VLC_USED static inline int vlc_clzl(unsigned long x)
 616 {
 617     return vlc_clzll(x) - ((sizeof (long long) - sizeof (long)) * 8);
 618 }
 619
 620 VLC_USED static inline int vlc_clz(unsigned x)
 621 {
 622     return vlc_clzll(x) - ((sizeof (long long) - sizeof (int)) * 8);
 623 }
 624
 625 VLC_USED static inline int vlc_ctz_generic(unsigned long long x)
 626 {
 627     unsigned i = sizeof (x) * 8;
 628
 629     while (x)
 630     {
 631         x <<= 1;
 632         i--;
 633     }
 634     return i;
 635 }
 636
 637 VLC_USED static inline int vlc_parity_generic(unsigned long long x)
 638 {
 639     for (unsigned i = 4 * sizeof (x); i > 0; i /= 2)
 640         x ^= x >> i;
 641     return x & 1;
 642 }
 643
 644 VLC_USED static inline int vlc_popcount_generic(unsigned long long x)
 645 {
 646     int count = 0;
 647     while (x)
 648     {
 649         count += x & 1;
 650         x = x >> 1;
 651     }
 652     return count;
 653 }
 654
 655 # define VLC_INT_FUNC_TYPE(basename,type,suffix) \
 656 VLC_USED static inline int vlc_##basename##suffix(type x) \
 657 { \
 658     return vlc_##basename##_generic(x); \
 659 }
 660 #endif
 661
 662 VLC_INT_FUNC(ctz)
 663 VLC_INT_FUNC(parity)
 664 VLC_INT_FUNC(popcount)
 665
 666 #ifndef __cplusplus
 667 # define VLC_INT_GENERIC(func,x) \
 668     _Generic((x), \
 669         unsigned char:      func(x), \
 670           signed char:      func(x), \
 671         unsigned short:     func(x), \
 672           signed short:     func(x), \
 673         unsigned int:       func(x), \
 674           signed int:       func(x), \
 675         unsigned long:      func##l(x), \
 676           signed long:      func##l(x), \
 677         unsigned long long: func##ll(x), \
 678           signed long long: func##ll(x))
 679
 680 /**
 681  * Count leading zeroes
 682  *
 683  * This function counts the number of consecutive zero (clear) bits
 684  * down from the highest order bit in an unsigned integer.
 685  *
 686  * \param x a non-zero integer
 687  * \note This macro assumes that CHAR_BIT equals 8.
 688  * \warning By definition, the result depends on the (width of the) type of x.
 689  * \return The number of leading zero bits in x.
 690  */
 691 # define clz(x) \
 692     _Generic((x), \
 693         unsigned char: (vlc_clz(x) - (sizeof (unsigned) - 1) * 8), \
 694         unsigned short: (vlc_clz(x) \
 695                 - (sizeof (unsigned) - sizeof (unsigned short)) * 8), \
 696         unsigned: vlc_clz(x), \
 697         unsigned long: vlc_clzl(x), \
 698         unsigned long long: vlc_clzll(x))
 699
 700 /**
 701  * Count trailing zeroes
 702  *
 703  * This function counts the number of consecutive zero bits
 704  * up from the lowest order bit in an unsigned integer.
 705  *
 706  * \param x a non-zero integer
 707  * \note This function assumes that CHAR_BIT equals 8.
 708  * \return The number of trailing zero bits in x.
 709  */
 710 # define ctz(x) VLC_INT_GENERIC(vlc_ctz, x)
 711
 712 /**
 713  * Parity
 714  *
 715  * This function determines the parity of an integer.
 716  * \retval 0 if x has an even number of set bits.
 717  * \retval 1 if x has an odd number of set bits.
 718  */
 719 # define parity(x) VLC_INT_GENERIC(vlc_parity, x)
 720
 721 /**
 722  * Bit weight / population count
 723  *
 724  * This function counts the number of non-zero bits in an integer.
 725  *
 726  * \return The count of non-zero bits.
 727  */
 728 # define vlc_popcount(x) \
 729     _Generic((x), \
 730         signed char:  vlc_popcount((unsigned char)(x)), \
 731         signed short: vlc_popcount((unsigned short)(x)), \
 732         default: VLC_INT_GENERIC(vlc_popcount ,x))
 733 #else
 734 VLC_USED static inline int vlc_popcount(unsigned char x)
 735 {
 736     return vlc_popcount((unsigned)x);
 737 }
 738
 739 VLC_USED static inline int vlc_popcount(unsigned short x)
 740 {
 741     return vlc_popcount((unsigned)x);
 742 }
 743
 744 VLC_USED static inline int vlc_popcount(unsigned long x)
 745 {
 746     return vlc_popcountl(x);
 747 }
 748
 749 VLC_USED static inline int vlc_popcount(unsigned long long x)
 750 {
 751     return vlc_popcountll(x);
 752 }
 753 #endif
 754
 755 /** Byte swap (16 bits) */
 756 VLC_USED
 757 static inline uint16_t vlc_bswap16(uint16_t x)
 758 {
 759     return (x << 8) | (x >> 8);
 760 }
 761
 762 /** Byte swap (32 bits) */
 763 VLC_USED
 764 static inline uint32_t vlc_bswap32(uint32_t x)
 765 {
 766 #if defined (__GNUC__) || defined(__clang__)
 767     return __builtin_bswap32 (x);
 768 #else
 769     return ((x & 0x000000FF) << 24)
 770          | ((x & 0x0000FF00) <<  8)
 771          | ((x & 0x00FF0000) >>  8)
 772          | ((x & 0xFF000000) >> 24);
 773 #endif
 774 }
 775
 776 /** Byte swap (64 bits) */
 777 VLC_USED
 778 static inline uint64_t vlc_bswap64(uint64_t x)
 779 {
 780 #if defined (__GNUC__) || defined(__clang__)
 781     return __builtin_bswap64 (x);
 782 #elif !defined (__cplusplus)
 783     return ((x & 0x00000000000000FF) << 56)
 784          | ((x & 0x000000000000FF00) << 40)
 785          | ((x & 0x0000000000FF0000) << 24)
 786          | ((x & 0x00000000FF000000) <<  8)
 787          | ((x & 0x000000FF00000000) >>  8)
 788          | ((x & 0x0000FF0000000000) >> 24)
 789          | ((x & 0x00FF000000000000) >> 40)
 790          | ((x & 0xFF00000000000000) >> 56);
 791 #else
 792     return ((x & 0x00000000000000FFULL) << 56)
 793          | ((x & 0x000000000000FF00ULL) << 40)
 794          | ((x & 0x0000000000FF0000ULL) << 24)
 795          | ((x & 0x00000000FF000000ULL) <<  8)
 796          | ((x & 0x000000FF00000000ULL) >>  8)
 797          | ((x & 0x0000FF0000000000ULL) >> 24)
 798          | ((x & 0x00FF000000000000ULL) >> 40)
 799          | ((x & 0xFF00000000000000ULL) >> 56);
 800 #endif
 801 }
 802 /** @} */
 803
 804 /**
 805  * \defgroup overflow Overflowing arithmetic
 806  * @{
 807  */
 808 static inline bool uadd_overflow(unsigned a, unsigned b, unsigned *res)
 809 {
 810 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 811      return __builtin_uadd_overflow(a, b, res);
 812 #else
 813      *res = a + b;
 814      return (a + b) < a;
 815 #endif
 816 }
 817
 818 static inline bool uaddl_overflow(unsigned long a, unsigned long b,
 819                                   unsigned long *res)
 820 {
 821 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 822      return __builtin_uaddl_overflow(a, b, res);
 823 #else
 824      *res = a + b;
 825      return (a + b) < a;
 826 #endif
 827 }
 828
 829 static inline bool uaddll_overflow(unsigned long long a, unsigned long long b,
 830                                    unsigned long long *res)
 831 {
 832 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 833      return __builtin_uaddll_overflow(a, b, res);
 834 #else
 835      *res = a + b;
 836      return (a + b) < a;
 837 #endif
 838 }
 839
 840 #ifndef __cplusplus
 841 /**
 842  * Overflowing addition
 843  *
 844  * Converts \p a and \p b to the type of \p *r.
 845  * Then computes the sum of both conversions while checking for overflow.
 846  * Finally stores the result in \p *r.
 847  *
 848  * \param a an integer
 849  * \param b an integer
 850  * \param r a pointer to an integer [OUT]
 851  * \retval false The sum did not overflow.
 852  * \retval true The sum overflowed.
 853  */
 854 # define add_overflow(a,b,r) \
 855     _Generic(*(r), \
 856         unsigned: uadd_overflow(a, b, (unsigned *)(r)), \
 857         unsigned long: uaddl_overflow(a, b, (unsigned long *)(r)), \
 858         unsigned long long: uaddll_overflow(a, b, (unsigned long long *)(r)))
 859 #else
 860 static inline bool add_overflow(unsigned a, unsigned b, unsigned *res)
 861 {
 862     return uadd_overflow(a, b, res);
 863 }
 864
 865 static inline bool add_overflow(unsigned long a, unsigned long b,
 866                                 unsigned long *res)
 867 {
 868     return uaddl_overflow(a, b, res);
 869 }
 870
 871 static inline bool add_overflow(unsigned long long a, unsigned long long b,
 872                                 unsigned long long *res)
 873 {
 874     return uaddll_overflow(a, b, res);
 875 }
 876 #endif
 877
 878 #if !(VLC_GCC_VERSION(5,0) || defined(__clang__))
 879 # include <limits.h>
 880 #endif
 881
 882 static inline bool umul_overflow(unsigned a, unsigned b, unsigned *res)
 883 {
 884 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 885      return __builtin_umul_overflow(a, b, res);
 886 #else
 887      *res = a * b;
 888      return b > 0 && a > (UINT_MAX / b);
 889 #endif
 890 }
 891
 892 static inline bool umull_overflow(unsigned long a, unsigned long b,
 893                                   unsigned long *res)
 894 {
 895 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 896      return __builtin_umull_overflow(a, b, res);
 897 #else
 898      *res = a * b;
 899      return b > 0 && a > (ULONG_MAX / b);
 900 #endif
 901 }
 902
 903 static inline bool umulll_overflow(unsigned long long a, unsigned long long b,
 904                                    unsigned long long *res)
 905 {
 906 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 907      return __builtin_umulll_overflow(a, b, res);
 908 #else
 909      *res = a * b;
 910      return b > 0 && a > (ULLONG_MAX / b);
 911 #endif
 912 }
 913
 914 #ifndef __cplusplus
 915 /**
 916  * Overflowing multiplication
 917  *
 918  * Converts \p a and \p b to the type of \p *r.
 919  * Then computes the product of both conversions while checking for overflow.
 920  * Finally stores the result in \p *r.
 921  *
 922  * \param a an integer
 923  * \param b an integer
 924  * \param r a pointer to an integer [OUT]
 925  * \retval false The product did not overflow.
 926  * \retval true The product overflowed.
 927  */
 928 #define mul_overflow(a,b,r) \
 929     _Generic(*(r), \
 930         unsigned: umul_overflow(a, b, (unsigned *)(r)), \
 931         unsigned long: umull_overflow(a, b, (unsigned long *)(r)), \
 932         unsigned long long: umulll_overflow(a, b, (unsigned long long *)(r)))
 933 #else
 934 static inline bool mul_overflow(unsigned a, unsigned b, unsigned *res)
 935 {
 936     return umul_overflow(a, b, res);
 937 }
 938
 939 static inline bool mul_overflow(unsigned long a, unsigned long b,
 940                                 unsigned long *res)
 941 {
 942     return umull_overflow(a, b, res);
 943 }
 944
 945 static inline bool mul_overflow(unsigned long long a, unsigned long long b,
 946                                 unsigned long long *res)
 947 {
 948     return umulll_overflow(a, b, res);
 949 }
 950 #endif
 951 /** @} */
 952 /** @} */
 953
 954 /* Free and set set the variable to NULL */
 955 #define FREENULL(a) do { free( a ); a = NULL; } while(0)
 956
 957 #define EMPTY_STR(str) (!str || !*str)
 958
 959 VLC_API char const * vlc_error( int ) VLC_USED;
 960
 961 #include <vlc_arrays.h>
 962
 963 /* MSB (big endian)/LSB (little endian) conversions - network order is always
 964  * MSB, and should be used for both network communications and files. */
 965
 966 #ifdef WORDS_BIGENDIAN
 967 # define hton16(i) ((uint16_t)(i))
 968 # define hton32(i) ((uint32_t)(i))
 969 # define hton64(i) ((uint64_t)(i))
 970 #else
 971 # define hton16(i) vlc_bswap16(i)
 972 # define hton32(i) vlc_bswap32(i)
 973 # define hton64(i) vlc_bswap64(i)
 974 #endif
 975 #define ntoh16(i) hton16(i)
 976 #define ntoh32(i) hton32(i)
 977 #define ntoh64(i) hton64(i)
 978
 979 /** Reads 16 bits in network byte order */
 980 VLC_USED
 981 static inline uint16_t U16_AT (const void *p)
 982 {
 983     uint16_t x;
 984
 985     memcpy (&x, p, sizeof (x));
 986     return ntoh16 (x);
 987 }
 988
 989 /** Reads 32 bits in network byte order */
 990 VLC_USED
 991 static inline uint32_t U32_AT (const void *p)
 992 {
 993     uint32_t x;
 994
 995     memcpy (&x, p, sizeof (x));
 996     return ntoh32 (x);
 997 }
 998
 999 /** Reads 64 bits in network byte order */
1000 VLC_USED
1001 static inline uint64_t U64_AT (const void *p)
1002 {
1003     uint64_t x;
1004
1005     memcpy (&x, p, sizeof (x));
1006     return ntoh64 (x);
1007 }
1008
1009 #define GetWBE(p)  U16_AT(p)
1010 #define GetDWBE(p) U32_AT(p)
1011 #define GetQWBE(p) U64_AT(p)
1012
1013 /** Reads 16 bits in little-endian order */
1014 VLC_USED
1015 static inline uint16_t GetWLE (const void *p)
1016 {
1017     uint16_t x;
1018
1019     memcpy (&x, p, sizeof (x));
1020 #ifdef WORDS_BIGENDIAN
1021     x = vlc_bswap16 (x);
1022 #endif
1023     return x;
1024 }
1025
1026 /** Reads 32 bits in little-endian order */
1027 VLC_USED
1028 static inline uint32_t GetDWLE (const void *p)
1029 {
1030     uint32_t x;
1031
1032     memcpy (&x, p, sizeof (x));
1033 #ifdef WORDS_BIGENDIAN
1034     x = vlc_bswap32 (x);
1035 #endif
1036     return x;
1037 }
1038
1039 /** Reads 64 bits in little-endian order */
1040 VLC_USED
1041 static inline uint64_t GetQWLE (const void *p)
1042 {
1043     uint64_t x;
1044
1045     memcpy (&x, p, sizeof (x));
1046 #ifdef WORDS_BIGENDIAN
1047     x = vlc_bswap64 (x);
1048 #endif
1049     return x;
1050 }
1051
1052 /** Writes 16 bits in network byte order */
1053 static inline void SetWBE (void *p, uint16_t w)
1054 {
1055     w = hton16 (w);
1056     memcpy (p, &w, sizeof (w));
1057 }
1058
1059 /** Writes 32 bits in network byte order */
1060 static inline void SetDWBE (void *p, uint32_t dw)
1061 {
1062     dw = hton32 (dw);
1063     memcpy (p, &dw, sizeof (dw));
1064 }
1065
1066 /** Writes 64 bits in network byte order */
1067 static inline void SetQWBE (void *p, uint64_t qw)
1068 {
1069     qw = hton64 (qw);
1070     memcpy (p, &qw, sizeof (qw));
1071 }
1072
1073 /** Writes 16 bits in little endian order */
1074 static inline void SetWLE (void *p, uint16_t w)
1075 {
1076 #ifdef WORDS_BIGENDIAN
1077     w = vlc_bswap16 (w);
1078 #endif
1079     memcpy (p, &w, sizeof (w));
1080 }
1081
1082 /** Writes 32 bits in little endian order */
1083 static inline void SetDWLE (void *p, uint32_t dw)
1084 {
1085 #ifdef WORDS_BIGENDIAN
1086     dw = vlc_bswap32 (dw);
1087 #endif
1088     memcpy (p, &dw, sizeof (dw));
1089 }
1090
1091 /** Writes 64 bits in little endian order */
1092 static inline void SetQWLE (void *p, uint64_t qw)
1093 {
1094 #ifdef WORDS_BIGENDIAN
1095     qw = vlc_bswap64 (qw);
1096 #endif
1097     memcpy (p, &qw, sizeof (qw));
1098 }
1099
1100 /* */
1101 #define VLC_UNUSED(x) (void)(x)
1102
1103 /* Stuff defined in src/extras/libc.c */
1104
1105 #if defined(_WIN32)
1106 /* several type definitions */
1107 #   if defined( __MINGW32__ )
1108 #       if !defined( _OFF_T_ )
1109             typedef long long _off_t;
1110             typedef _off_t off_t;
1111 #           define _OFF_T_
1112 #       else
1113 #           ifdef off_t
1114 #               undef off_t
1115 #           endif
1116 #           define off_t long long
1117 #       endif
1118 #   endif
1119
1120 #   ifndef O_NONBLOCK
1121 #       define O_NONBLOCK 0
1122 #   endif
1123
1124 #   include <tchar.h>
1125 #endif /* _WIN32 */
1126
1127 typedef struct {
1128     unsigned num, den;
1129 } vlc_rational_t;
1130
1131 VLC_API bool vlc_ureduce( unsigned *, unsigned *, uint64_t, uint64_t, uint64_t );
1132
1133 #define container_of(ptr, type, member) \
1134     ((type *)(((char *)(ptr)) - offsetof(type, member)))
1135
1136 VLC_USED VLC_MALLOC
1137 static inline void *vlc_alloc(size_t count, size_t size)
1138 {
1139     return mul_overflow(count, size, &size) ? NULL : malloc(size);
1140 }
1141
1142 /*****************************************************************************
1143  * I18n stuff
1144  *****************************************************************************/
1145 VLC_API char *vlc_gettext( const char *msgid ) VLC_FORMAT_ARG(1);
1146 VLC_API char *vlc_ngettext( const char *s, const char *p, unsigned long n ) VLC_FORMAT_ARG(1) VLC_FORMAT_ARG(2);
1147
1148 #define vlc_pgettext( ctx, id ) \
1149         vlc_pgettext_aux( ctx "\004" id, id )
1150
1151 VLC_FORMAT_ARG(2)
1152 static inline const char *vlc_pgettext_aux( const char *ctx, const char *id )
1153 {
1154     const char *tr = vlc_gettext( ctx );
1155     return (tr == ctx) ? id : tr;
1156 }
1157
1158 /*****************************************************************************
1159  * Loosy memory allocation functions. Do not use in new code.
1160  *****************************************************************************/
1161 static inline void *xmalloc(size_t len)
1162 {
1163     void *ptr = malloc(len);
1164     if (unlikely(ptr == NULL && len > 0))
1165         abort();
1166     return ptr;
1167 }
1168
1169 static inline void *xrealloc(void *ptr, size_t len)
1170 {
1171     void *nptr = realloc(ptr, len);
1172     if (unlikely(nptr == NULL && len > 0))
1173         abort();
1174     return nptr;
1175 }
1176
1177 static inline void *xcalloc(size_t n, size_t size)
1178 {
1179     void *ptr = calloc(n, size);
1180     if (unlikely(ptr == NULL && (n > 0 || size > 0)))
1181         abort ();
1182     return ptr;
1183 }
1184
1185 static inline char *xstrdup (const char *str)
1186 {
1187     char *ptr = strdup (str);
1188     if (unlikely(ptr == NULL))
1189         abort ();
1190     return ptr;
1191 }
1192
1193 /*****************************************************************************
1194  * libvlc features
1195  *****************************************************************************/
1196 VLC_API const char * VLC_CompileBy( void ) VLC_USED;
1197 VLC_API const char * VLC_CompileHost( void ) VLC_USED;
1198 VLC_API const char * VLC_Compiler( void ) VLC_USED;
1199
1200 /*****************************************************************************
1201  * Additional vlc stuff
1202  *****************************************************************************/
1203 #include "vlc_messages.h"
1204 #include "vlc_objects.h"
1205 #include "vlc_variables.h"
1206 #include "vlc_configuration.h"
1207
1208 #if defined( _WIN32 ) || defined( __OS2__ )
1209 #   define DIR_SEP_CHAR '\\'
1210 #   define DIR_SEP "\\"
1211 #   define PATH_SEP_CHAR ';'
1212 #   define PATH_SEP ";"
1213 #else
1214 #   define DIR_SEP_CHAR '/'
1215 #   define DIR_SEP "/"
1216 #   define PATH_SEP_CHAR ':'
1217 #   define PATH_SEP ":"
1218 #endif
1219
1220 #define LICENSE_MSG \
1221   _("This program comes with NO WARRANTY, to the extent permitted by " \
1222     "law.\nYou may redistribute it under the terms of the GNU General " \
1223     "Public License;\nsee the file named COPYING for details.\n" \
1224     "Written by the VideoLAN team; see the AUTHORS file.\n")
1225
1226 #endif /* !VLC_COMMON_H */