src/mesa/glapi/glapi.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /*
  27  * This file manages the OpenGL API dispatch layer.
  28  * The dispatch table (struct _glapi_table) is basically just a list
  29  * of function pointers.
  30  * There are functions to set/get the current dispatch table for the
  31  * current thread and to manage registration/dispatch of dynamically
  32  * added extension functions.
  33  *
  34  * It's intended that this file and the other glapi*.[ch] files are
  35  * flexible enough to be reused in several places:  XFree86, DRI-
  36  * based libGL.so, and perhaps the SGI SI.
  37  *
  38  * NOTE: There are no dependencies on Mesa in this code.
  39  *
  40  * Versions (API changes):
  41  *   2000/02/23  - original version for Mesa 3.3 and XFree86 4.0
  42  *   2001/01/16  - added dispatch override feature for Mesa 3.5
  43  *   2002/06/28  - added _glapi_set_warning_func(), Mesa 4.1.
  44  *   2002/10/01  - _glapi_get_proc_address() will now generate new entrypoints
  45  *                 itself (using offset ~0).  _glapi_add_entrypoint() can be
  46  *                 called afterward and it'll fill in the correct dispatch
  47  *                 offset.  This allows DRI libGL to avoid probing for DRI
  48  *                 drivers!  No changes to the public glapi interface.
  49  */
  50
  51
  52
  53 #ifdef HAVE_DIX_CONFIG_H
  54
  55 #include <dix-config.h>
  56 #define PUBLIC
  57
  58 #else
  59
  60 #include "main/glheader.h"
  61
  62 #endif
  63
  64 #include "main/compiler.h"
  65
  66 #include <stdlib.h>
  67 #include <string.h>
  68 #ifdef DEBUG
  69 #include <assert.h>
  70 #endif
  71
  72 #include "glapi/glapi.h"
  73 #include "glapi/glapioffsets.h"
  74 #include "glapi/glapitable.h"
  75
  76 extern _glapi_proc __glapi_noop_table[];
  77
  78
  79 /**
  80  * \name Current dispatch and current context control variables
  81  *
  82  * Depending on whether or not multithreading is support, and the type of
  83  * support available, several variables are used to store the current context
  84  * pointer and the current dispatch table pointer.  In the non-threaded case,
  85  * the variables \c _glapi_Dispatch and \c _glapi_Context are used for this
  86  * purpose.
  87  *
  88  * In the "normal" threaded case, the variables \c _glapi_Dispatch and
  89  * \c _glapi_Context will be \c NULL if an application is detected as being
  90  * multithreaded.  Single-threaded applications will use \c _glapi_Dispatch
  91  * and \c _glapi_Context just like the case without any threading support.
  92  * When \c _glapi_Dispatch and \c _glapi_Context are \c NULL, the thread state
  93  * data \c _gl_DispatchTSD and \c ContextTSD are used.  Drivers and the
  94  * static dispatch functions access these variables via \c _glapi_get_dispatch
  95  * and \c _glapi_get_context.
  96  *
  97  * There is a race condition in setting \c _glapi_Dispatch to \c NULL.  It is
  98  * possible for the original thread to be setting it at the same instant a new
  99  * thread, perhaps running on a different processor, is clearing it.  Because
 100  * of that, \c ThreadSafe, which can only ever be changed to \c GL_TRUE, is
 101  * used to determine whether or not the application is multithreaded.
 102  *
 103  * In the TLS case, the variables \c _glapi_Dispatch and \c _glapi_Context are
 104  * hardcoded to \c NULL.  Instead the TLS variables \c _glapi_tls_Dispatch and
 105  * \c _glapi_tls_Context are used.  Having \c _glapi_Dispatch and
 106  * \c _glapi_Context be hardcoded to \c NULL maintains binary compatability
 107  * between TLS enabled loaders and non-TLS DRI drivers.
 108  */
 109 /*@{*/
 110 #if defined(GLX_USE_TLS)
 111
 112 PUBLIC __thread struct _glapi_table * _glapi_tls_Dispatch
 113     __attribute__((tls_model("initial-exec")))
 114     = (struct _glapi_table *) __glapi_noop_table;
 115
 116 PUBLIC __thread void * _glapi_tls_Context
 117     __attribute__((tls_model("initial-exec")));
 118
 119 PUBLIC const struct _glapi_table *_glapi_Dispatch = NULL;
 120 PUBLIC const void *_glapi_Context = NULL;
 121
 122 #else
 123
 124 #if defined(THREADS)
 125
 126 #ifdef WIN32_THREADS
 127 /* _glthread_DECLARE_STATIC_MUTEX is broken on windows.  There will be race! */
 128 #define CHECK_MULTITHREAD_LOCK()
 129 #define CHECK_MULTITHREAD_UNLOCK()
 130 #else
 131 _glthread_DECLARE_STATIC_MUTEX(ThreadCheckMutex);
 132 #define CHECK_MULTITHREAD_LOCK() _glthread_LOCK_MUTEX(ThreadCheckMutex)
 133 #define CHECK_MULTITHREAD_UNLOCK() _glthread_UNLOCK_MUTEX(ThreadCheckMutex)
 134 #endif
 135
 136 static GLboolean ThreadSafe = GL_FALSE;  /**< In thread-safe mode? */
 137 _glthread_TSD _gl_DispatchTSD;           /**< Per-thread dispatch pointer */
 138 static _glthread_TSD ContextTSD;         /**< Per-thread context pointer */
 139
 140 #if defined(WIN32_THREADS)
 141 void FreeTSD(_glthread_TSD *p);
 142 void FreeAllTSD(void)
 143 {
 144    FreeTSD(&_gl_DispatchTSD);
 145    FreeTSD(&ContextTSD);
 146 }
 147 #endif /* defined(WIN32_THREADS) */
 148
 149 #endif /* defined(THREADS) */
 150
 151 PUBLIC struct _glapi_table *_glapi_Dispatch =
 152   (struct _glapi_table *) __glapi_noop_table;
 153 PUBLIC void *_glapi_Context = NULL;
 154
 155 #endif /* defined(GLX_USE_TLS) */
 156 /*@}*/
 157
 158
 159
 160
 161 /**
 162  * We should call this periodically from a function such as glXMakeCurrent
 163  * in order to test if multiple threads are being used.
 164  */
 165 PUBLIC void
 166 _glapi_check_multithread(void)
 167 {
 168 #if defined(THREADS) && !defined(GLX_USE_TLS)
 169    static unsigned long knownID;
 170    static GLboolean firstCall = GL_TRUE;
 171
 172    if (ThreadSafe)
 173       return;
 174
 175    CHECK_MULTITHREAD_LOCK();
 176    if (firstCall) {
 177       /* initialize TSDs */
 178       (void) _glthread_GetTSD(&ContextTSD);
 179       (void) _glthread_GetTSD(&_gl_DispatchTSD);
 180
 181       knownID = _glthread_GetID();
 182       firstCall = GL_FALSE;
 183    }
 184    else if (knownID != _glthread_GetID()) {
 185       ThreadSafe = GL_TRUE;
 186       _glapi_set_dispatch(NULL);
 187       _glapi_set_context(NULL);
 188    }
 189    CHECK_MULTITHREAD_UNLOCK();
 190 #endif
 191 }
 192
 193
 194
 195 /**
 196  * Set the current context pointer for this thread.
 197  * The context pointer is an opaque type which should be cast to
 198  * void from the real context pointer type.
 199  */
 200 PUBLIC void
 201 _glapi_set_context(void *context)
 202 {
 203 #if defined(GLX_USE_TLS)
 204    _glapi_tls_Context = context;
 205 #elif defined(THREADS)
 206    _glthread_SetTSD(&ContextTSD, context);
 207    _glapi_Context = (ThreadSafe) ? NULL : context;
 208 #else
 209    _glapi_Context = context;
 210 #endif
 211 }
 212
 213
 214
 215 /**
 216  * Get the current context pointer for this thread.
 217  * The context pointer is an opaque type which should be cast from
 218  * void to the real context pointer type.
 219  */
 220 PUBLIC void *
 221 _glapi_get_context(void)
 222 {
 223 #if defined(GLX_USE_TLS)
 224    return _glapi_tls_Context;
 225 #elif defined(THREADS)
 226    if (ThreadSafe) {
 227       return _glthread_GetTSD(&ContextTSD);
 228    }
 229    else {
 230       return _glapi_Context;
 231    }
 232 #else
 233    return _glapi_Context;
 234 #endif
 235 }
 236
 237 #ifdef USE_X86_ASM
 238
 239 #if defined( GLX_USE_TLS )
 240 extern       GLubyte gl_dispatch_functions_start[];
 241 extern       GLubyte gl_dispatch_functions_end[];
 242 #else
 243 extern const GLubyte gl_dispatch_functions_start[];
 244 #endif
 245
 246 #endif /* USE_X86_ASM */
 247
 248
 249 #if defined(USE_X64_64_ASM) && defined(GLX_USE_TLS)
 250 # define DISPATCH_FUNCTION_SIZE  16
 251 #elif defined(USE_X86_ASM)
 252 # if defined(THREADS) && !defined(GLX_USE_TLS)
 253 #  define DISPATCH_FUNCTION_SIZE  32
 254 # else
 255 #  define DISPATCH_FUNCTION_SIZE  16
 256 # endif
 257 #endif
 258
 259 #ifdef USE_SPARC_ASM
 260 #ifdef GLX_USE_TLS
 261 extern unsigned int __glapi_sparc_tls_stub;
 262 #else
 263 extern unsigned int __glapi_sparc_pthread_stub;
 264 #endif
 265 #endif
 266
 267 #if !defined(DISPATCH_FUNCTION_SIZE) && !defined(XFree86Server) && !defined(XGLServer)
 268 # define NEED_FUNCTION_POINTER
 269 #endif
 270
 271 #if defined(PTHREADS) || defined(GLX_USE_TLS)
 272 /**
 273  * Perform platform-specific GL API entry-point fixups.
 274  */
 275 static void
 276 init_glapi_relocs( void )
 277 {
 278 #if defined(USE_X86_ASM) && defined(GLX_USE_TLS) && !defined(GLX_X86_READONLY_TEXT)
 279     extern unsigned long _x86_get_dispatch(void);
 280     char run_time_patch[] = {
 281        0x65, 0xa1, 0, 0, 0, 0 /* movl %gs:0,%eax */
 282     };
 283     GLuint *offset = (GLuint *) &run_time_patch[2]; /* 32-bits for x86/32 */
 284     const GLubyte * const get_disp = (const GLubyte *) run_time_patch;
 285     GLubyte * curr_func = (GLubyte *) gl_dispatch_functions_start;
 286
 287     *offset = _x86_get_dispatch();
 288     while ( curr_func != (GLubyte *) gl_dispatch_functions_end ) {
 289         (void) memcpy( curr_func, get_disp, sizeof(run_time_patch));
 290         curr_func += DISPATCH_FUNCTION_SIZE;
 291     }
 292 #endif
 293 #ifdef USE_SPARC_ASM
 294     extern void __glapi_sparc_icache_flush(unsigned int *);
 295     static const unsigned int template[] = {
 296 #ifdef GLX_USE_TLS
 297         0x05000000, /* sethi %hi(_glapi_tls_Dispatch), %g2 */
 298         0x8730e00a, /* srl %g3, 10, %g3 */
 299         0x8410a000, /* or %g2, %lo(_glapi_tls_Dispatch), %g2 */
 300 #ifdef __arch64__
 301         0xc259c002, /* ldx [%g7 + %g2], %g1 */
 302         0xc2584003, /* ldx [%g1 + %g3], %g1 */
 303 #else
 304         0xc201c002, /* ld [%g7 + %g2], %g1 */
 305         0xc2004003, /* ld [%g1 + %g3], %g1 */
 306 #endif
 307         0x81c04000, /* jmp %g1 */
 308         0x01000000, /* nop  */
 309 #else
 310 #ifdef __arch64__
 311         0x03000000, /* 64-bit 0x00 --> sethi %hh(_glapi_Dispatch), %g1 */
 312         0x05000000, /* 64-bit 0x04 --> sethi %lm(_glapi_Dispatch), %g2 */
 313         0x82106000, /* 64-bit 0x08 --> or %g1, %hm(_glapi_Dispatch), %g1 */
 314         0x8730e00a, /* 64-bit 0x0c --> srl %g3, 10, %g3 */
 315         0x83287020, /* 64-bit 0x10 --> sllx %g1, 32, %g1 */
 316         0x82004002, /* 64-bit 0x14 --> add %g1, %g2, %g1 */
 317         0xc2586000, /* 64-bit 0x18 --> ldx [%g1 + %lo(_glapi_Dispatch)], %g1 */
 318 #else
 319         0x03000000, /* 32-bit 0x00 --> sethi %hi(_glapi_Dispatch), %g1 */
 320         0x8730e00a, /* 32-bit 0x04 --> srl %g3, 10, %g3 */
 321         0xc2006000, /* 32-bit 0x08 --> ld [%g1 + %lo(_glapi_Dispatch)], %g1 */
 322 #endif
 323         0x80a06000, /*             --> cmp %g1, 0 */
 324         0x02800005, /*             --> be +4*5 */
 325         0x01000000, /*             -->  nop  */
 326 #ifdef __arch64__
 327         0xc2584003, /* 64-bit      --> ldx [%g1 + %g3], %g1 */
 328 #else
 329         0xc2004003, /* 32-bit      --> ld [%g1 + %g3], %g1 */
 330 #endif
 331         0x81c04000, /*             --> jmp %g1 */
 332         0x01000000, /*             --> nop  */
 333 #ifdef __arch64__
 334         0x9de3bf80, /* 64-bit      --> save  %sp, -128, %sp */
 335 #else
 336         0x9de3bfc0, /* 32-bit      --> save  %sp, -64, %sp */
 337 #endif
 338         0xa0100003, /*             --> mov  %g3, %l0 */
 339         0x40000000, /*             --> call _glapi_get_dispatch */
 340         0x01000000, /*             -->  nop */
 341         0x82100008, /*             --> mov %o0, %g1 */
 342         0x86100010, /*             --> mov %l0, %g3 */
 343         0x10bffff7, /*             --> ba -4*9 */
 344         0x81e80000, /*             -->  restore  */
 345 #endif
 346     };
 347 #ifdef GLX_USE_TLS
 348     extern unsigned long __glapi_sparc_get_dispatch(void);
 349     unsigned int *code = &__glapi_sparc_tls_stub;
 350     unsigned long dispatch = __glapi_sparc_get_dispatch();
 351 #else
 352     unsigned int *code = &__glapi_sparc_pthread_stub;
 353     unsigned long dispatch = (unsigned long) &_glapi_Dispatch;
 354     unsigned long call_dest = (unsigned long ) &_glapi_get_dispatch;
 355     int idx;
 356 #endif
 357
 358 #if defined(GLX_USE_TLS)
 359     code[0] = template[0] | (dispatch >> 10);
 360     code[1] = template[1];
 361     __glapi_sparc_icache_flush(&code[0]);
 362     code[2] = template[2] | (dispatch & 0x3ff);
 363     code[3] = template[3];
 364     __glapi_sparc_icache_flush(&code[2]);
 365     code[4] = template[4];
 366     code[5] = template[5];
 367     __glapi_sparc_icache_flush(&code[4]);
 368     code[6] = template[6];
 369     __glapi_sparc_icache_flush(&code[6]);
 370 #else
 371 #if defined(__arch64__)
 372     code[0] = template[0] | (dispatch >> (32 + 10));
 373     code[1] = template[1] | ((dispatch & 0xffffffff) >> 10);
 374     __glapi_sparc_icache_flush(&code[0]);
 375     code[2] = template[2] | ((dispatch >> 32) & 0x3ff);
 376     code[3] = template[3];
 377     __glapi_sparc_icache_flush(&code[2]);
 378     code[4] = template[4];
 379     code[5] = template[5];
 380     __glapi_sparc_icache_flush(&code[4]);
 381     code[6] = template[6] | (dispatch & 0x3ff);
 382     idx = 7;
 383 #else
 384     code[0] = template[0] | (dispatch >> 10);
 385     code[1] = template[1];
 386     __glapi_sparc_icache_flush(&code[0]);
 387     code[2] = template[2] | (dispatch & 0x3ff);
 388     idx = 3;
 389 #endif
 390     code[idx + 0] = template[idx + 0];
 391     __glapi_sparc_icache_flush(&code[idx - 1]);
 392     code[idx + 1] = template[idx + 1];
 393     code[idx + 2] = template[idx + 2];
 394     __glapi_sparc_icache_flush(&code[idx + 1]);
 395     code[idx + 3] = template[idx + 3];
 396     code[idx + 4] = template[idx + 4];
 397     __glapi_sparc_icache_flush(&code[idx + 3]);
 398     code[idx + 5] = template[idx + 5];
 399     code[idx + 6] = template[idx + 6];
 400     __glapi_sparc_icache_flush(&code[idx + 5]);
 401     code[idx + 7] = template[idx + 7];
 402     code[idx + 8] = template[idx + 8] |
 403             (((call_dest - ((unsigned long) &code[idx + 8]))
 404               >> 2) & 0x3fffffff);
 405     __glapi_sparc_icache_flush(&code[idx + 7]);
 406     code[idx + 9] = template[idx + 9];
 407     code[idx + 10] = template[idx + 10];
 408     __glapi_sparc_icache_flush(&code[idx + 9]);
 409     code[idx + 11] = template[idx + 11];
 410     code[idx + 12] = template[idx + 12];
 411     __glapi_sparc_icache_flush(&code[idx + 11]);
 412     code[idx + 13] = template[idx + 13];
 413     __glapi_sparc_icache_flush(&code[idx + 13]);
 414 #endif
 415 #endif
 416 }
 417 #endif /* defined(PTHREADS) || defined(GLX_USE_TLS) */
 418
 419
 420 /**
 421  * Set the global or per-thread dispatch table pointer.
 422  * If the dispatch parameter is NULL we'll plug in the no-op dispatch
 423  * table (__glapi_noop_table).
 424  */
 425 PUBLIC void
 426 _glapi_set_dispatch(struct _glapi_table *dispatch)
 427 {
 428 #if defined(PTHREADS) || defined(GLX_USE_TLS)
 429    static pthread_once_t once_control = PTHREAD_ONCE_INIT;
 430    pthread_once( & once_control, init_glapi_relocs );
 431 #endif
 432
 433    if (!dispatch) {
 434       /* use the no-op functions */
 435       dispatch = (struct _glapi_table *) __glapi_noop_table;
 436    }
 437 #ifdef DEBUG
 438    else {
 439       _glapi_check_table(dispatch);
 440    }
 441 #endif
 442
 443 #if defined(GLX_USE_TLS)
 444    _glapi_tls_Dispatch = dispatch;
 445 #elif defined(THREADS)
 446    _glthread_SetTSD(&_gl_DispatchTSD, (void *) dispatch);
 447    _glapi_Dispatch = (ThreadSafe) ? NULL : dispatch;
 448 #else /*THREADS*/
 449    _glapi_Dispatch = dispatch;
 450 #endif /*THREADS*/
 451 }
 452
 453
 454
 455 /**
 456  * Return pointer to current dispatch table for calling thread.
 457  */
 458 PUBLIC struct _glapi_table *
 459 _glapi_get_dispatch(void)
 460 {
 461    struct _glapi_table * api;
 462 #if defined(GLX_USE_TLS)
 463    api = _glapi_tls_Dispatch;
 464 #elif defined(THREADS)
 465    api = (ThreadSafe)
 466      ? (struct _glapi_table *) _glthread_GetTSD(&_gl_DispatchTSD)
 467      : _glapi_Dispatch;
 468 #else
 469    api = _glapi_Dispatch;
 470 #endif
 471    return api;
 472 }
 473
 474
 475
 476
 477 /*
 478  * The dispatch table size (number of entries) is the size of the
 479  * _glapi_table struct plus the number of dynamic entries we can add.
 480  * The extra slots can be filled in by DRI drivers that register new extension
 481  * functions.
 482  */
 483 #define DISPATCH_TABLE_SIZE (sizeof(struct _glapi_table) / sizeof(void *) + MAX_EXTENSION_FUNCS)
 484
 485
 486 /**
 487  * Return size of dispatch table struct as number of functions (or
 488  * slots).
 489  */
 490 PUBLIC GLuint
 491 _glapi_get_dispatch_table_size(void)
 492 {
 493    return DISPATCH_TABLE_SIZE;
 494 }
 495
 496
 497 /**
 498  * Make sure there are no NULL pointers in the given dispatch table.
 499  * Intended for debugging purposes.
 500  */
 501 void
 502 _glapi_check_table(const struct _glapi_table *table)
 503 {
 504 #ifdef EXTRA_DEBUG
 505    const GLuint entries = _glapi_get_dispatch_table_size();
 506    const void **tab = (const void **) table;
 507    GLuint i;
 508    for (i = 1; i < entries; i++) {
 509       assert(tab[i]);
 510    }
 511
 512    /* Do some spot checks to be sure that the dispatch table
 513     * slots are assigned correctly.
 514     */
 515    {
 516       GLuint BeginOffset = _glapi_get_proc_offset("glBegin");
 517       char *BeginFunc = (char*) &table->Begin;
 518       GLuint offset = (BeginFunc - (char *) table) / sizeof(void *);
 519       assert(BeginOffset == _gloffset_Begin);
 520       assert(BeginOffset == offset);
 521    }
 522    {
 523       GLuint viewportOffset = _glapi_get_proc_offset("glViewport");
 524       char *viewportFunc = (char*) &table->Viewport;
 525       GLuint offset = (viewportFunc - (char *) table) / sizeof(void *);
 526       assert(viewportOffset == _gloffset_Viewport);
 527       assert(viewportOffset == offset);
 528    }
 529    {
 530       GLuint VertexPointerOffset = _glapi_get_proc_offset("glVertexPointer");
 531       char *VertexPointerFunc = (char*) &table->VertexPointer;
 532       GLuint offset = (VertexPointerFunc - (char *) table) / sizeof(void *);
 533       assert(VertexPointerOffset == _gloffset_VertexPointer);
 534       assert(VertexPointerOffset == offset);
 535    }
 536    {
 537       GLuint ResetMinMaxOffset = _glapi_get_proc_offset("glResetMinmax");
 538       char *ResetMinMaxFunc = (char*) &table->ResetMinmax;
 539       GLuint offset = (ResetMinMaxFunc - (char *) table) / sizeof(void *);
 540       assert(ResetMinMaxOffset == _gloffset_ResetMinmax);
 541       assert(ResetMinMaxOffset == offset);
 542    }
 543    {
 544       GLuint blendColorOffset = _glapi_get_proc_offset("glBlendColor");
 545       char *blendColorFunc = (char*) &table->BlendColor;
 546       GLuint offset = (blendColorFunc - (char *) table) / sizeof(void *);
 547       assert(blendColorOffset == _gloffset_BlendColor);
 548       assert(blendColorOffset == offset);
 549    }
 550    {
 551       GLuint secondaryColor3fOffset = _glapi_get_proc_offset("glSecondaryColor3fEXT");
 552       char *secondaryColor3fFunc = (char*) &table->SecondaryColor3fEXT;
 553       GLuint offset = (secondaryColor3fFunc - (char *) table) / sizeof(void *);
 554       assert(secondaryColor3fOffset == _gloffset_SecondaryColor3fEXT);
 555       assert(secondaryColor3fOffset == offset);
 556    }
 557    {
 558       GLuint pointParameterivOffset = _glapi_get_proc_offset("glPointParameterivNV");
 559       char *pointParameterivFunc = (char*) &table->PointParameterivNV;
 560       GLuint offset = (pointParameterivFunc - (char *) table) / sizeof(void *);
 561       assert(pointParameterivOffset == _gloffset_PointParameterivNV);
 562       assert(pointParameterivOffset == offset);
 563    }
 564    {
 565       GLuint setFenceOffset = _glapi_get_proc_offset("glSetFenceNV");
 566       char *setFenceFunc = (char*) &table->SetFenceNV;
 567       GLuint offset = (setFenceFunc - (char *) table) / sizeof(void *);
 568       assert(setFenceOffset == _gloffset_SetFenceNV);
 569       assert(setFenceOffset == offset);
 570    }
 571 #else
 572    (void) table;
 573 #endif
 574 }