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() (vlc_assert(!"unreachable"), unreachable())
 250
 251 /**
 252  * Run-time assertion
 253  *
 254  * This macro performs a run-time assertion if C assertions are enabled
 255  * and the following preprocessor symbol is defined:
 256  * @verbatim __LIBVLC__ @endverbatim
 257  * That restriction ensures that assertions in public header files are not
 258  * unwittingly <i>leaked</i> to externally-compiled plug-ins
 259  * including those header files.
 260  *
 261  * Within the LibVLC code base, this is exactly the same as assert(), which can
 262  * and probably should be used directly instead.
 263  */
 264 #ifdef __LIBVLC__
 265 # define vlc_assert(pred) assert(pred)
 266 #else
 267 # define vlc_assert(pred) ((void)0)
 268 #endif
 269
 270 /* Linkage */
 271 #ifdef __cplusplus
 272 # define VLC_EXTERN extern "C"
 273 #else
 274 # define VLC_EXTERN
 275 #endif
 276
 277 #if defined (_WIN32) && defined (DLL_EXPORT)
 278 # define VLC_EXPORT __declspec(dllexport)
 279 #elif defined (__GNUC__)
 280 # define VLC_EXPORT __attribute__((visibility("default")))
 281 #else
 282 # define VLC_EXPORT
 283 #endif
 284
 285 /**
 286  * Exported API call annotation
 287  *
 288  * This macro is placed before a function declaration to indicate that the
 289  * function is an API call of the LibVLC plugin API.
 290  */
 291 #define VLC_API VLC_EXTERN VLC_EXPORT
 292
 293 /** @} */
 294
 295 /*****************************************************************************
 296  * Basic types definitions
 297  *****************************************************************************/
 298 /**
 299  * The vlc_fourcc_t type.
 300  *
 301  * See http://www.webartz.com/fourcc/ for a very detailed list.
 302  */
 303 typedef uint32_t vlc_fourcc_t;
 304
 305 #ifdef WORDS_BIGENDIAN
 306 #   define VLC_FOURCC( a, b, c, d ) \
 307         ( ((uint32_t)d) | ( ((uint32_t)c) << 8 ) \
 308            | ( ((uint32_t)b) << 16 ) | ( ((uint32_t)a) << 24 ) )
 309 #   define VLC_TWOCC( a, b ) \
 310         ( (uint16_t)(b) | ( (uint16_t)(a) << 8 ) )
 311
 312 #else
 313 #   define VLC_FOURCC( a, b, c, d ) \
 314         ( ((uint32_t)a) | ( ((uint32_t)b) << 8 ) \
 315            | ( ((uint32_t)c) << 16 ) | ( ((uint32_t)d) << 24 ) )
 316 #   define VLC_TWOCC( a, b ) \
 317         ( (uint16_t)(a) | ( (uint16_t)(b) << 8 ) )
 318
 319 #endif
 320
 321 /**
 322  * Translate a vlc_fourcc into its string representation. This function
 323  * assumes there is enough room in psz_fourcc to store 4 characters in.
 324  *
 325  * \param fcc a vlc_fourcc_t
 326  * \param psz_fourcc string to store string representation of vlc_fourcc in
 327  */
 328 static inline void vlc_fourcc_to_char( vlc_fourcc_t fcc, char *psz_fourcc )
 329 {
 330     memcpy( psz_fourcc, &fcc, 4 );
 331 }
 332
 333 /*****************************************************************************
 334  * Classes declaration
 335  *****************************************************************************/
 336
 337 /* Internal types */
 338 typedef struct vlc_object_t vlc_object_t;
 339 typedef struct libvlc_int_t libvlc_int_t;
 340 typedef struct date_t date_t;
 341
 342 /* Playlist */
 343
 344 typedef struct playlist_t playlist_t;
 345 typedef struct playlist_item_t playlist_item_t;
 346 typedef struct services_discovery_t services_discovery_t;
 347 typedef struct vlc_renderer_discovery_t vlc_renderer_discovery_t;
 348 typedef struct vlc_renderer_item_t vlc_renderer_item_t;
 349
 350 /* Modules */
 351 typedef struct module_t module_t;
 352 typedef struct module_config_t module_config_t;
 353
 354 typedef struct config_category_t config_category_t;
 355
 356 /* Input */
 357 typedef struct input_thread_t input_thread_t;
 358 typedef struct input_item_t input_item_t;
 359 typedef struct input_item_node_t input_item_node_t;
 360 typedef struct stream_t     stream_t;
 361 typedef struct stream_t demux_t;
 362 typedef struct es_out_t     es_out_t;
 363 typedef struct es_out_id_t  es_out_id_t;
 364 typedef struct seekpoint_t seekpoint_t;
 365 typedef struct info_t info_t;
 366 typedef struct info_category_t info_category_t;
 367 typedef struct input_attachment_t input_attachment_t;
 368
 369 /* Format */
 370 typedef struct audio_format_t audio_format_t;
 371 typedef struct video_format_t video_format_t;
 372 typedef struct subs_format_t subs_format_t;
 373 typedef struct es_format_t es_format_t;
 374 typedef struct video_palette_t video_palette_t;
 375
 376 /* Audio */
 377 typedef struct audio_output audio_output_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
 387 /* Subpictures */
 388 typedef struct spu_t spu_t;
 389 typedef struct subpicture_t subpicture_t;
 390 typedef struct subpicture_region_t subpicture_region_t;
 391
 392 typedef struct image_handler_t image_handler_t;
 393
 394 /* Stream output */
 395 typedef struct sout_instance_t sout_instance_t;
 396
 397 typedef struct sout_input_t sout_input_t;
 398 typedef struct sout_packetizer_input_t sout_packetizer_input_t;
 399
 400 typedef struct sout_access_out_t sout_access_out_t;
 401
 402 typedef struct sout_mux_t sout_mux_t;
 403
 404 typedef struct sout_stream_t    sout_stream_t;
 405
 406 typedef struct config_chain_t       config_chain_t;
 407 typedef struct session_descriptor_t session_descriptor_t;
 408
 409 /* Decoders */
 410 typedef struct decoder_t         decoder_t;
 411 typedef struct decoder_synchro_t decoder_synchro_t;
 412
 413 /* Encoders */
 414 typedef struct encoder_t      encoder_t;
 415
 416 /* Filters */
 417 typedef struct filter_t filter_t;
 418
 419 /* Network */
 420 typedef struct vlc_url_t vlc_url_t;
 421
 422 /* Misc */
 423 typedef struct iso639_lang_t iso639_lang_t;
 424
 425 /* block */
 426 typedef struct block_t      block_t;
 427 typedef struct block_fifo_t block_fifo_t;
 428
 429 /* Hashing */
 430 typedef struct md5_s md5_t;
 431
 432 /* XML */
 433 typedef struct xml_t xml_t;
 434 typedef struct xml_reader_t xml_reader_t;
 435
 436 /* vod server */
 437 typedef struct vod_t     vod_t;
 438 typedef struct vod_media_t vod_media_t;
 439
 440 /* VLM */
 441 typedef struct vlm_t         vlm_t;
 442 typedef struct vlm_message_t vlm_message_t;
 443
 444 /* misc */
 445 typedef struct vlc_meta_t    vlc_meta_t;
 446 typedef struct input_stats_t input_stats_t;
 447 typedef struct addon_entry_t addon_entry_t;
 448
 449 /* Update */
 450 typedef struct update_t update_t;
 451
 452 /**
 453  * VLC value structure
 454  */
 455 typedef union
 456 {
 457     int64_t         i_int;
 458     bool            b_bool;
 459     float           f_float;
 460     char *          psz_string;
 461     void *          p_address;
 462     struct { int32_t x; int32_t y; } coords;
 463
 464 } vlc_value_t;
 465
 466 /*****************************************************************************
 467  * Error values (shouldn't be exposed)
 468  *****************************************************************************/
 469 #define VLC_SUCCESS        (-0) /**< No error */
 470 #define VLC_EGENERIC       (-1) /**< Unspecified error */
 471 #define VLC_ENOMEM         (-2) /**< Not enough memory */
 472 #define VLC_ETIMEOUT       (-3) /**< Timeout */
 473 #define VLC_ENOMOD         (-4) /**< Module not found */
 474 #define VLC_ENOOBJ         (-5) /**< Object not found */
 475 #define VLC_ENOVAR         (-6) /**< Variable not found */
 476 #define VLC_EBADVAR        (-7) /**< Bad variable value */
 477 #define VLC_ENOITEM        (-8) /**< Item not found */
 478
 479 /*****************************************************************************
 480  * Variable callbacks: called when the value is modified
 481  *****************************************************************************/
 482 typedef int ( * vlc_callback_t ) ( vlc_object_t *,      /* variable's object */
 483                                    char const *,            /* variable name */
 484                                    vlc_value_t,                 /* old value */
 485                                    vlc_value_t,                 /* new value */
 486                                    void * );                /* callback data */
 487
 488 /*****************************************************************************
 489  * List callbacks: called when elements are added/removed from the list
 490  *****************************************************************************/
 491 typedef int ( * vlc_list_callback_t ) ( vlc_object_t *,      /* variable's object */
 492                                         char const *,            /* variable name */
 493                                         int,                  /* VLC_VAR_* action */
 494                                         vlc_value_t *,      /* new/deleted value  */
 495                                         void *);                 /* callback data */
 496
 497 /*****************************************************************************
 498  * OS-specific headers and thread types
 499  *****************************************************************************/
 500 #if defined( _WIN32 )
 501 #   include <malloc.h>
 502 #   ifndef PATH_MAX
 503 #       define PATH_MAX MAX_PATH
 504 #   endif
 505 #   include <windows.h>
 506 #endif
 507
 508 #ifdef __APPLE__
 509 #include <sys/syslimits.h>
 510 #include <AvailabilityMacros.h>
 511 #endif
 512
 513 #ifdef __OS2__
 514 #   define OS2EMX_PLAIN_CHAR
 515 #   define INCL_BASE
 516 #   define INCL_PM
 517 #   include <os2safe.h>
 518 #   include <os2.h>
 519 #endif
 520
 521 #include "vlc_tick.h"
 522 #include "vlc_threads.h"
 523
 524 /**
 525  * \defgroup intops Integer operations
 526  * \ingroup cext
 527  *
 528  * Common integer functions.
 529  * @{
 530  */
 531 /* __MAX and __MIN: self explanatory */
 532 #ifndef __MAX
 533 #   define __MAX(a, b)   ( ((a) > (b)) ? (a) : (b) )
 534 #endif
 535 #ifndef __MIN
 536 #   define __MIN(a, b)   ( ((a) < (b)) ? (a) : (b) )
 537 #endif
 538
 539 /* clip v in [min, max] */
 540 #define VLC_CLIP(v, min, max)    __MIN(__MAX((v), (min)), (max))
 541
 542 /** Greatest common divisor */
 543 VLC_USED
 544 static inline int64_t GCD ( int64_t a, int64_t b )
 545 {
 546     while( b )
 547     {
 548         int64_t c = a % b;
 549         a = b;
 550         b = c;
 551     }
 552     return a;
 553 }
 554
 555 /* function imported from libavutil/common.h */
 556 VLC_USED
 557 static inline uint8_t clip_uint8_vlc( int32_t a )
 558 {
 559     if( a&(~255) ) return (-a)>>31;
 560     else           return a;
 561 }
 562
 563 /**
 564  * \defgroup bitops Bit operations
 565  * @{
 566  */
 567
 568 #define VLC_INT_FUNC(basename) \
 569         VLC_INT_FUNC_TYPE(basename, unsigned, ) \
 570         VLC_INT_FUNC_TYPE(basename, unsigned long, l) \
 571         VLC_INT_FUNC_TYPE(basename, unsigned long long, ll)
 572
 573 #if defined (__GNUC__) || defined (__clang__)
 574 # define VLC_INT_FUNC_TYPE(basename,type,suffix) \
 575 VLC_USED static inline int vlc_##basename##suffix(type x) \
 576 { \
 577     return __builtin_##basename##suffix(x); \
 578 }
 579
 580 VLC_INT_FUNC(clz)
 581 #else
 582 VLC_USED static inline int vlc_clzll(unsigned long long x)
 583 {
 584     int i = sizeof (x) * 8;
 585
 586     while (x)
 587     {
 588         x >>= 1;
 589         i--;
 590     }
 591     return i;
 592 }
 593
 594 VLC_USED static inline int vlc_clzl(unsigned long x)
 595 {
 596     return vlc_clzll(x) - ((sizeof (long long) - sizeof (long)) * 8);
 597 }
 598
 599 VLC_USED static inline int vlc_clz(unsigned x)
 600 {
 601     return vlc_clzll(x) - ((sizeof (long long) - sizeof (int)) * 8);
 602 }
 603
 604 VLC_USED static inline int vlc_ctz_generic(unsigned long long x)
 605 {
 606     unsigned i = sizeof (x) * 8;
 607
 608     while (x)
 609     {
 610         x <<= 1;
 611         i--;
 612     }
 613     return i;
 614 }
 615
 616 VLC_USED static inline int vlc_parity_generic(unsigned long long x)
 617 {
 618     for (unsigned i = 4 * sizeof (x); i > 0; i /= 2)
 619         x ^= x >> i;
 620     return x & 1;
 621 }
 622
 623 VLC_USED static inline int vlc_popcount_generic(unsigned long long x)
 624 {
 625     int count = 0;
 626     while (x)
 627     {
 628         count += x & 1;
 629         x = x >> 1;
 630     }
 631     return count;
 632 }
 633
 634 # define VLC_INT_FUNC_TYPE(basename,type,suffix) \
 635 VLC_USED static inline int vlc_##basename##suffix(type x) \
 636 { \
 637     return vlc_##basename##_generic(x); \
 638 }
 639 #endif
 640
 641 VLC_INT_FUNC(ctz)
 642 VLC_INT_FUNC(parity)
 643 VLC_INT_FUNC(popcount)
 644
 645 #ifndef __cplusplus
 646 # define VLC_INT_GENERIC(func,x) \
 647     _Generic((x), \
 648         unsigned char:      func(x), \
 649           signed char:      func(x), \
 650         unsigned short:     func(x), \
 651           signed short:     func(x), \
 652         unsigned int:       func(x), \
 653           signed int:       func(x), \
 654         unsigned long:      func##l(x), \
 655           signed long:      func##l(x), \
 656         unsigned long long: func##ll(x), \
 657           signed long long: func##ll(x))
 658
 659 /**
 660  * Count leading zeroes
 661  *
 662  * This function counts the number of consecutive zero (clear) bits
 663  * down from the highest order bit in an unsigned integer.
 664  *
 665  * \param x a non-zero integer
 666  * \note This macro assumes that CHAR_BIT equals 8.
 667  * \warning By definition, the result depends on the (width of the) type of x.
 668  * \return The number of leading zero bits in x.
 669  */
 670 # define clz(x) \
 671     _Generic((x), \
 672         unsigned char: (vlc_clz(x) - (sizeof (unsigned) - 1) * 8), \
 673         unsigned short: (vlc_clz(x) \
 674         - (sizeof (unsigned) - sizeof (unsigned short)) * 8), \
 675         unsigned: vlc_clz(x), \
 676         unsigned long: vlc_clzl(x), \
 677         unsigned long long: vlc_clzll(x))
 678
 679 /**
 680  * Count trailing zeroes
 681  *
 682  * This function counts the number of consecutive zero bits
 683  * up from the lowest order bit in an unsigned integer.
 684  *
 685  * \param x a non-zero integer
 686  * \note This function assumes that CHAR_BIT equals 8.
 687  * \return The number of trailing zero bits in x.
 688  */
 689 # define ctz(x) VLC_INT_GENERIC(vlc_ctz, x)
 690
 691 /**
 692  * Parity
 693  *
 694  * This function determines the parity of an integer.
 695  * \retval 0 if x has an even number of set bits.
 696  * \retval 1 if x has an odd number of set bits.
 697  */
 698 # define parity(x) VLC_INT_GENERIC(vlc_parity, x)
 699
 700 /**
 701  * Bit weight / population count
 702  *
 703  * This function counts the number of non-zero bits in an integer.
 704  *
 705  * \return The count of non-zero bits.
 706  */
 707 # define vlc_popcount(x) \
 708     _Generic((x), \
 709         signed char:  vlc_popcount((unsigned char)(x)), \
 710         signed short: vlc_popcount((unsigned short)(x)), \
 711         default: VLC_INT_GENERIC(vlc_popcount ,x))
 712 #else
 713 VLC_USED static inline int vlc_popcount(unsigned char x)
 714 {
 715     return vlc_popcount((unsigned)x);
 716 }
 717
 718 VLC_USED static inline int vlc_popcount(unsigned short x)
 719 {
 720     return vlc_popcount((unsigned)x);
 721 }
 722
 723 VLC_USED static inline int vlc_popcount(unsigned long x)
 724 {
 725     return vlc_popcountl(x);
 726 }
 727
 728 VLC_USED static inline int vlc_popcount(unsigned long long x)
 729 {
 730     return vlc_popcountll(x);
 731 }
 732 #endif
 733
 734 /** Byte swap (16 bits) */
 735 VLC_USED
 736 static inline uint16_t vlc_bswap16(uint16_t x)
 737 {
 738     return (x << 8) | (x >> 8);
 739 }
 740
 741 /** Byte swap (32 bits) */
 742 VLC_USED
 743 static inline uint32_t vlc_bswap32(uint32_t x)
 744 {
 745 #if defined (__GNUC__) || defined(__clang__)
 746     return __builtin_bswap32 (x);
 747 #else
 748     return ((x & 0x000000FF) << 24)
 749          | ((x & 0x0000FF00) <<  8)
 750          | ((x & 0x00FF0000) >>  8)
 751          | ((x & 0xFF000000) >> 24);
 752 #endif
 753 }
 754
 755 /** Byte swap (64 bits) */
 756 VLC_USED
 757 static inline uint64_t vlc_bswap64(uint64_t x)
 758 {
 759 #if defined (__GNUC__) || defined(__clang__)
 760     return __builtin_bswap64 (x);
 761 #elif !defined (__cplusplus)
 762     return ((x & 0x00000000000000FF) << 56)
 763          | ((x & 0x000000000000FF00) << 40)
 764          | ((x & 0x0000000000FF0000) << 24)
 765          | ((x & 0x00000000FF000000) <<  8)
 766          | ((x & 0x000000FF00000000) >>  8)
 767          | ((x & 0x0000FF0000000000) >> 24)
 768          | ((x & 0x00FF000000000000) >> 40)
 769          | ((x & 0xFF00000000000000) >> 56);
 770 #else
 771     return ((x & 0x00000000000000FFULL) << 56)
 772          | ((x & 0x000000000000FF00ULL) << 40)
 773          | ((x & 0x0000000000FF0000ULL) << 24)
 774          | ((x & 0x00000000FF000000ULL) <<  8)
 775          | ((x & 0x000000FF00000000ULL) >>  8)
 776          | ((x & 0x0000FF0000000000ULL) >> 24)
 777          | ((x & 0x00FF000000000000ULL) >> 40)
 778          | ((x & 0xFF00000000000000ULL) >> 56);
 779 #endif
 780 }
 781 /** @} */
 782
 783 /**
 784  * \defgroup overflow Overflowing arithmetic
 785  * @{
 786  */
 787 static inline bool uadd_overflow(unsigned a, unsigned b, unsigned *res)
 788 {
 789 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 790      return __builtin_uadd_overflow(a, b, res);
 791 #else
 792      *res = a + b;
 793      return (a + b) < a;
 794 #endif
 795 }
 796
 797 static inline bool uaddl_overflow(unsigned long a, unsigned long b,
 798                                   unsigned long *res)
 799 {
 800 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 801      return __builtin_uaddl_overflow(a, b, res);
 802 #else
 803      *res = a + b;
 804      return (a + b) < a;
 805 #endif
 806 }
 807
 808 static inline bool uaddll_overflow(unsigned long long a, unsigned long long b,
 809                                    unsigned long long *res)
 810 {
 811 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 812      return __builtin_uaddll_overflow(a, b, res);
 813 #else
 814      *res = a + b;
 815      return (a + b) < a;
 816 #endif
 817 }
 818
 819 #ifndef __cplusplus
 820 /**
 821  * Overflowing addition
 822  *
 823  * Converts \p a and \p b to the type of \p *r.
 824  * Then computes the sum of both conversions while checking for overflow.
 825  * Finally stores the result in \p *r.
 826  *
 827  * \param a an integer
 828  * \param b an integer
 829  * \param r a pointer to an integer [OUT]
 830  * \retval false The sum did not overflow.
 831  * \retval true The sum overflowed.
 832  */
 833 # define add_overflow(a,b,r) \
 834     _Generic(*(r), \
 835         unsigned: uadd_overflow(a, b, (unsigned *)(r)), \
 836         unsigned long: uaddl_overflow(a, b, (unsigned long *)(r)), \
 837         unsigned long long: uaddll_overflow(a, b, (unsigned long long *)(r)))
 838 #else
 839 static inline bool add_overflow(unsigned a, unsigned b, unsigned *res)
 840 {
 841     return uadd_overflow(a, b, res);
 842 }
 843
 844 static inline bool add_overflow(unsigned long a, unsigned long b,
 845                                 unsigned long *res)
 846 {
 847     return uaddl_overflow(a, b, res);
 848 }
 849
 850 static inline bool add_overflow(unsigned long long a, unsigned long long b,
 851                                 unsigned long long *res)
 852 {
 853     return uaddll_overflow(a, b, res);
 854 }
 855 #endif
 856
 857 #if !(VLC_GCC_VERSION(5,0) || defined(__clang__))
 858 # include <limits.h>
 859 #endif
 860
 861 static inline bool umul_overflow(unsigned a, unsigned b, unsigned *res)
 862 {
 863 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 864      return __builtin_umul_overflow(a, b, res);
 865 #else
 866      *res = a * b;
 867      return b > 0 && a > (UINT_MAX / b);
 868 #endif
 869 }
 870
 871 static inline bool umull_overflow(unsigned long a, unsigned long b,
 872                                   unsigned long *res)
 873 {
 874 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 875      return __builtin_umull_overflow(a, b, res);
 876 #else
 877      *res = a * b;
 878      return b > 0 && a > (ULONG_MAX / b);
 879 #endif
 880 }
 881
 882 static inline bool umulll_overflow(unsigned long long a, unsigned long long b,
 883                                    unsigned long long *res)
 884 {
 885 #if VLC_GCC_VERSION(5,0) || defined(__clang__)
 886      return __builtin_umulll_overflow(a, b, res);
 887 #else
 888      *res = a * b;
 889      return b > 0 && a > (ULLONG_MAX / b);
 890 #endif
 891 }
 892
 893 #ifndef __cplusplus
 894 /**
 895  * Overflowing multiplication
 896  *
 897  * Converts \p a and \p b to the type of \p *r.
 898  * Then computes the product of both conversions while checking for overflow.
 899  * Finally stores the result in \p *r.
 900  *
 901  * \param a an integer
 902  * \param b an integer
 903  * \param r a pointer to an integer [OUT]
 904  * \retval false The product did not overflow.
 905  * \retval true The product overflowed.
 906  */
 907 #define mul_overflow(a,b,r) \
 908     _Generic(*(r), \
 909         unsigned: umul_overflow(a, b, (unsigned *)(r)), \
 910         unsigned long: umull_overflow(a, b, (unsigned long *)(r)), \
 911         unsigned long long: umulll_overflow(a, b, (unsigned long long *)(r)))
 912 #else
 913 static inline bool mul_overflow(unsigned a, unsigned b, unsigned *res)
 914 {
 915     return umul_overflow(a, b, res);
 916 }
 917
 918 static inline bool mul_overflow(unsigned long a, unsigned long b,
 919                                 unsigned long *res)
 920 {
 921     return umull_overflow(a, b, res);
 922 }
 923
 924 static inline bool mul_overflow(unsigned long long a, unsigned long long b,
 925                                 unsigned long long *res)
 926 {
 927     return umulll_overflow(a, b, res);
 928 }
 929 #endif
 930 /** @} */
 931 /** @} */
 932
 933 /* Free and set set the variable to NULL */
 934 #define FREENULL(a) do { free( a ); a = NULL; } while(0)
 935
 936 #define EMPTY_STR(str) (!str || !*str)
 937
 938 VLC_API char const * vlc_error( int ) VLC_USED;
 939
 940 #include <vlc_arrays.h>
 941
 942 /* MSB (big endian)/LSB (little endian) conversions - network order is always
 943  * MSB, and should be used for both network communications and files. */
 944
 945 #ifdef WORDS_BIGENDIAN
 946 # define hton16(i) ((uint16_t)(i))
 947 # define hton32(i) ((uint32_t)(i))
 948 # define hton64(i) ((uint64_t)(i))
 949 #else
 950 # define hton16(i) vlc_bswap16(i)
 951 # define hton32(i) vlc_bswap32(i)
 952 # define hton64(i) vlc_bswap64(i)
 953 #endif
 954 #define ntoh16(i) hton16(i)
 955 #define ntoh32(i) hton32(i)
 956 #define ntoh64(i) hton64(i)
 957
 958 /** Reads 16 bits in network byte order */
 959 VLC_USED
 960 static inline uint16_t U16_AT (const void *p)
 961 {
 962     uint16_t x;
 963
 964     memcpy (&x, p, sizeof (x));
 965     return ntoh16 (x);
 966 }
 967
 968 /** Reads 32 bits in network byte order */
 969 VLC_USED
 970 static inline uint32_t U32_AT (const void *p)
 971 {
 972     uint32_t x;
 973
 974     memcpy (&x, p, sizeof (x));
 975     return ntoh32 (x);
 976 }
 977
 978 /** Reads 64 bits in network byte order */
 979 VLC_USED
 980 static inline uint64_t U64_AT (const void *p)
 981 {
 982     uint64_t x;
 983
 984     memcpy (&x, p, sizeof (x));
 985     return ntoh64 (x);
 986 }
 987
 988 #define GetWBE(p)  U16_AT(p)
 989 #define GetDWBE(p) U32_AT(p)
 990 #define GetQWBE(p) U64_AT(p)
 991
 992 /** Reads 16 bits in little-endian order */
 993 VLC_USED
 994 static inline uint16_t GetWLE (const void *p)
 995 {
 996     uint16_t x;
 997
 998     memcpy (&x, p, sizeof (x));
 999 #ifdef WORDS_BIGENDIAN
1000     x = vlc_bswap16 (x);
1001 #endif
1002     return x;
1003 }
1004
1005 /** Reads 32 bits in little-endian order */
1006 VLC_USED
1007 static inline uint32_t GetDWLE (const void *p)
1008 {
1009     uint32_t x;
1010
1011     memcpy (&x, p, sizeof (x));
1012 #ifdef WORDS_BIGENDIAN
1013     x = vlc_bswap32 (x);
1014 #endif
1015     return x;
1016 }
1017
1018 /** Reads 64 bits in little-endian order */
1019 VLC_USED
1020 static inline uint64_t GetQWLE (const void *p)
1021 {
1022     uint64_t x;
1023
1024     memcpy (&x, p, sizeof (x));
1025 #ifdef WORDS_BIGENDIAN
1026     x = vlc_bswap64 (x);
1027 #endif
1028     return x;
1029 }
1030
1031 /** Writes 16 bits in network byte order */
1032 static inline void SetWBE (void *p, uint16_t w)
1033 {
1034     w = hton16 (w);
1035     memcpy (p, &w, sizeof (w));
1036 }
1037
1038 /** Writes 32 bits in network byte order */
1039 static inline void SetDWBE (void *p, uint32_t dw)
1040 {
1041     dw = hton32 (dw);
1042     memcpy (p, &dw, sizeof (dw));
1043 }
1044
1045 /** Writes 64 bits in network byte order */
1046 static inline void SetQWBE (void *p, uint64_t qw)
1047 {
1048     qw = hton64 (qw);
1049     memcpy (p, &qw, sizeof (qw));
1050 }
1051
1052 /** Writes 16 bits in little endian order */
1053 static inline void SetWLE (void *p, uint16_t w)
1054 {
1055 #ifdef WORDS_BIGENDIAN
1056     w = vlc_bswap16 (w);
1057 #endif
1058     memcpy (p, &w, sizeof (w));
1059 }
1060
1061 /** Writes 32 bits in little endian order */
1062 static inline void SetDWLE (void *p, uint32_t dw)
1063 {
1064 #ifdef WORDS_BIGENDIAN
1065     dw = vlc_bswap32 (dw);
1066 #endif
1067     memcpy (p, &dw, sizeof (dw));
1068 }
1069
1070 /** Writes 64 bits in little endian order */
1071 static inline void SetQWLE (void *p, uint64_t qw)
1072 {
1073 #ifdef WORDS_BIGENDIAN
1074     qw = vlc_bswap64 (qw);
1075 #endif
1076     memcpy (p, &qw, sizeof (qw));
1077 }
1078
1079 /* */
1080 #define VLC_UNUSED(x) (void)(x)
1081
1082 /* Stuff defined in src/extras/libc.c */
1083
1084 #if defined(_WIN32)
1085 /* several type definitions */
1086 #   if defined( __MINGW32__ )
1087 #       if !defined( _OFF_T_ )
1088             typedef long long _off_t;
1089             typedef _off_t off_t;
1090 #           define _OFF_T_
1091 #       else
1092 #           ifdef off_t
1093 #               undef off_t
1094 #           endif
1095 #           define off_t long long
1096 #       endif
1097 #   endif
1098
1099 #   ifndef O_NONBLOCK
1100 #       define O_NONBLOCK 0
1101 #   endif
1102
1103 #   include <tchar.h>
1104 #endif /* _WIN32 */
1105
1106 typedef struct {
1107     unsigned num, den;
1108 } vlc_rational_t;
1109
1110 VLC_API bool vlc_ureduce( unsigned *, unsigned *, uint64_t, uint64_t, uint64_t );
1111
1112 #define container_of(ptr, type, member) \
1113     ((type *)(((char *)(ptr)) - offsetof(type, member)))
1114
1115 VLC_USED VLC_MALLOC
1116 static inline void *vlc_alloc(size_t count, size_t size)
1117 {
1118     return mul_overflow(count, size, &size) ? NULL : malloc(size);
1119 }
1120
1121 /*****************************************************************************
1122  * I18n stuff
1123  *****************************************************************************/
1124 VLC_API const char *vlc_gettext(const char *msgid) VLC_FORMAT_ARG(1);
1125 VLC_API const char *vlc_ngettext(const char *s, const char *p, unsigned long n)
1126 VLC_FORMAT_ARG(1) VLC_FORMAT_ARG(2);
1127
1128 #define vlc_pgettext( ctx, id ) \
1129         vlc_pgettext_aux( ctx "\004" id, id )
1130
1131 VLC_FORMAT_ARG(2)
1132 static inline const char *vlc_pgettext_aux( const char *ctx, const char *id )
1133 {
1134     const char *tr = vlc_gettext( ctx );
1135     return (tr == ctx) ? id : tr;
1136 }
1137
1138 /*****************************************************************************
1139  * Loosy memory allocation functions. Do not use in new code.
1140  *****************************************************************************/
1141 static inline void *xmalloc(size_t len)
1142 {
1143     void *ptr = malloc(len);
1144     if (unlikely(ptr == NULL && len > 0))
1145         abort();
1146     return ptr;
1147 }
1148
1149 static inline void *xrealloc(void *ptr, size_t len)
1150 {
1151     void *nptr = realloc(ptr, len);
1152     if (unlikely(nptr == NULL && len > 0))
1153         abort();
1154     return nptr;
1155 }
1156
1157 static inline void *xcalloc(size_t n, size_t size)
1158 {
1159     void *ptr = calloc(n, size);
1160     if (unlikely(ptr == NULL && (n > 0 || size > 0)))
1161         abort ();
1162     return ptr;
1163 }
1164
1165 static inline char *xstrdup (const char *str)
1166 {
1167     char *ptr = strdup (str);
1168     if (unlikely(ptr == NULL))
1169         abort ();
1170     return ptr;
1171 }
1172
1173 /*****************************************************************************
1174  * libvlc features
1175  *****************************************************************************/
1176 VLC_API const char * VLC_CompileBy( void ) VLC_USED;
1177 VLC_API const char * VLC_CompileHost( void ) VLC_USED;
1178 VLC_API const char * VLC_Compiler( void ) VLC_USED;
1179
1180 /*****************************************************************************
1181  * Additional vlc stuff
1182  *****************************************************************************/
1183 #include "vlc_messages.h"
1184 #include "vlc_objects.h"
1185 #include "vlc_variables.h"
1186 #include "vlc_configuration.h"
1187
1188 #if defined( _WIN32 ) || defined( __OS2__ )
1189 #   define DIR_SEP_CHAR '\\'
1190 #   define DIR_SEP "\\"
1191 #   define PATH_SEP_CHAR ';'
1192 #   define PATH_SEP ";"
1193 #else
1194 #   define DIR_SEP_CHAR '/'
1195 #   define DIR_SEP "/"
1196 #   define PATH_SEP_CHAR ':'
1197 #   define PATH_SEP ":"
1198 #endif
1199
1200 #define LICENSE_MSG \
1201   _("This program comes with NO WARRANTY, to the extent permitted by " \
1202     "law.\nYou may redistribute it under the terms of the GNU General " \
1203     "Public License;\nsee the file named COPYING for details.\n" \
1204     "Written by the VideoLAN team; see the AUTHORS file.\n")
1205
1206 #endif /* !VLC_COMMON_H */