src/mesa/glapi/glapi.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.3
   4  *
   5  * Copyright (C) 1999-2003  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 #include "glheader.h"
  54 #include "glapi.h"
  55 #include "glapioffsets.h"
  56 #include "glapitable.h"
  57
  58 /***** BEGIN NO-OP DISPATCH *****/
  59
  60 static GLboolean WarnFlag = GL_FALSE;
  61 static _glapi_warning_func warning_func;
  62
  63 static void init_glapi_relocs(void);
  64
  65 static _glapi_proc generate_entrypoint(GLuint functionOffset);
  66 static void fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset);
  67
  68 /*
  69  * Enable/disable printing of warning messages.
  70  */
  71 PUBLIC void
  72 _glapi_noop_enable_warnings(GLboolean enable)
  73 {
  74    WarnFlag = enable;
  75 }
  76
  77 /*
  78  * Register a callback function for reporting errors.
  79  */
  80 PUBLIC void
  81 _glapi_set_warning_func( _glapi_warning_func func )
  82 {
  83    warning_func = func;
  84 }
  85
  86 static GLboolean
  87 warn(void)
  88 {
  89    if ((WarnFlag || getenv("MESA_DEBUG") || getenv("LIBGL_DEBUG"))
  90        && warning_func) {
  91       return GL_TRUE;
  92    }
  93    else {
  94       return GL_FALSE;
  95    }
  96 }
  97
  98
  99 #define KEYWORD1 static
 100 #define KEYWORD2 GLAPIENTRY
 101 #define NAME(func)  NoOp##func
 102
 103 #define F NULL
 104
 105 #define DISPATCH(func, args, msg)                                             \
 106    if (warn()) {                                                              \
 107       warning_func(NULL, "GL User Error: called without context: %s", #func); \
 108    }
 109
 110 #define RETURN_DISPATCH(func, args, msg)                                      \
 111    if (warn()) {                                                              \
 112       warning_func(NULL, "GL User Error: called without context: %s", #func); \
 113    }                                                                          \
 114    return 0
 115
 116 #define DISPATCH_TABLE_NAME __glapi_noop_table
 117 #define UNUSED_TABLE_NAME __unused_noop_functions
 118
 119 #define TABLE_ENTRY(name) (_glapi_proc) NoOp##name
 120
 121 static GLint NoOpUnused(void)
 122 {
 123    if (warn()) {
 124       warning_func(NULL, "GL User Error: calling extension function without a current context\n");
 125    }
 126    return 0;
 127 }
 128
 129 #include "glapitemp.h"
 130
 131 /***** END NO-OP DISPATCH *****/
 132
 133
 134
 135 /**
 136  * \name Current dispatch and current context control variables
 137  *
 138  * Depending on whether or not multithreading is support, and the type of
 139  * support available, several variables are used to store the current context
 140  * pointer and the current dispatch table pointer.  In the non-threaded case,
 141  * the variables \c _glapi_Dispatch and \c _glapi_Context are used for this
 142  * purpose.
 143  *
 144  * In the "normal" threaded case, the variables \c _glapi_Dispatch and
 145  * \c _glapi_Context will be \c NULL if an application is detected as being
 146  * multithreaded.  Single-threaded applications will use \c _glapi_Dispatch
 147  * and \c _glapi_Context just like the case without any threading support.
 148  * When \c _glapi_Dispatch and \c _glapi_Context are \c NULL, the thread state
 149  * data \c _gl_DispatchTSD and \c ContextTSD are used.  Drivers and the
 150  * static dispatch functions access these variables via \c _glapi_get_dispatch
 151  * and \c _glapi_get_context.
 152  *
 153  * There is a race condition in setting \c _glapi_Dispatch to \c NULL.  It is
 154  * possible for the original thread to be setting it at the same instant a new
 155  * thread, perhaps running on a different processor, is clearing it.  Because
 156  * of that, \c ThreadSafe, which can only ever be changed to \c GL_TRUE, is
 157  * used to determine whether or not the application is multithreaded.
 158  *
 159  * In the TLS case, the variables \c _glapi_Dispatch and \c _glapi_Context are
 160  * hardcoded to \c NULL.  Instead the TLS variables \c _glapi_tls_Dispatch and
 161  * \c _glapi_tls_Context are used.  Having \c _glapi_Dispatch and
 162  * \c _glapi_Context be hardcoded to \c NULL maintains binary compatability
 163  * between TLS enabled loaders and non-TLS DRI drivers.
 164  */
 165 /*@{*/
 166 #if defined(GLX_USE_TLS)
 167
 168 PUBLIC __thread struct _glapi_table * _glapi_tls_Dispatch
 169     __attribute__((tls_model("initial-exec")))
 170     = (struct _glapi_table *) __glapi_noop_table;
 171
 172 PUBLIC __thread void * _glapi_tls_Context
 173     __attribute__((tls_model("initial-exec")));
 174
 175 PUBLIC const struct _glapi_table *_glapi_Dispatch = NULL;
 176 PUBLIC const void *_glapi_Context = NULL;
 177
 178 #else
 179
 180 #if defined(THREADS)
 181
 182 static GLboolean ThreadSafe = GL_FALSE;  /**< In thread-safe mode? */
 183 _glthread_TSD _gl_DispatchTSD;           /**< Per-thread dispatch pointer */
 184 static _glthread_TSD ContextTSD;         /**< Per-thread context pointer */
 185
 186 #endif /* defined(THREADS) */
 187
 188 PUBLIC struct _glapi_table *_glapi_Dispatch =
 189   (struct _glapi_table *) __glapi_noop_table;
 190 PUBLIC void *_glapi_Context = NULL;
 191
 192 #endif /* defined(GLX_USE_TLS) */
 193 /*@}*/
 194
 195
 196 /**
 197  * strdup() is actually not a standard ANSI C or POSIX routine.
 198  * Irix will not define it if ANSI mode is in effect.
 199  */
 200 static char *
 201 str_dup(const char *str)
 202 {
 203    char *copy;
 204    copy = (char*) malloc(strlen(str) + 1);
 205    if (!copy)
 206       return NULL;
 207    strcpy(copy, str);
 208    return copy;
 209 }
 210
 211
 212
 213 /**
 214  * We should call this periodically from a function such as glXMakeCurrent
 215  * in order to test if multiple threads are being used.
 216  */
 217 void
 218 _glapi_check_multithread(void)
 219 {
 220 #if defined(THREADS) && !defined(GLX_USE_TLS)
 221    if (!ThreadSafe) {
 222       static unsigned long knownID;
 223       static GLboolean firstCall = GL_TRUE;
 224       if (firstCall) {
 225          knownID = _glthread_GetID();
 226          firstCall = GL_FALSE;
 227       }
 228       else if (knownID != _glthread_GetID()) {
 229          ThreadSafe = GL_TRUE;
 230          _glapi_set_dispatch(NULL);
 231       }
 232    }
 233    else if (!_glapi_get_dispatch()) {
 234       /* make sure that this thread's dispatch pointer isn't null */
 235       _glapi_set_dispatch(NULL);
 236    }
 237 #endif
 238 }
 239
 240
 241
 242 /**
 243  * Set the current context pointer for this thread.
 244  * The context pointer is an opaque type which should be cast to
 245  * void from the real context pointer type.
 246  */
 247 PUBLIC void
 248 _glapi_set_context(void *context)
 249 {
 250    (void) __unused_noop_functions; /* silence a warning */
 251 #if defined(GLX_USE_TLS)
 252    _glapi_tls_Context = context;
 253 #elif defined(THREADS)
 254    _glthread_SetTSD(&ContextTSD, context);
 255    _glapi_Context = (ThreadSafe) ? NULL : context;
 256 #else
 257    _glapi_Context = context;
 258 #endif
 259 }
 260
 261
 262
 263 /**
 264  * Get the current context pointer for this thread.
 265  * The context pointer is an opaque type which should be cast from
 266  * void to the real context pointer type.
 267  */
 268 PUBLIC void *
 269 _glapi_get_context(void)
 270 {
 271 #if defined(GLX_USE_TLS)
 272    return _glapi_tls_Context;
 273 #elif defined(THREADS)
 274    if (ThreadSafe) {
 275       return _glthread_GetTSD(&ContextTSD);
 276    }
 277    else {
 278       return _glapi_Context;
 279    }
 280 #else
 281    return _glapi_Context;
 282 #endif
 283 }
 284
 285
 286
 287 /**
 288  * Set the global or per-thread dispatch table pointer.
 289  */
 290 PUBLIC void
 291 _glapi_set_dispatch(struct _glapi_table *dispatch)
 292 {
 293 #if defined(PTHREADS) || defined(GLX_USE_TLS)
 294    static pthread_once_t once_control = PTHREAD_ONCE_INIT;
 295
 296
 297    pthread_once( & once_control, init_glapi_relocs );
 298 #endif
 299
 300    if (!dispatch) {
 301       /* use the no-op functions */
 302       dispatch = (struct _glapi_table *) __glapi_noop_table;
 303    }
 304 #ifdef DEBUG
 305    else {
 306       _glapi_check_table(dispatch);
 307    }
 308 #endif
 309
 310 #if defined(GLX_USE_TLS)
 311    _glapi_tls_Dispatch = dispatch;
 312 #elif defined(THREADS)
 313    _glthread_SetTSD(&_gl_DispatchTSD, (void *) dispatch);
 314    _glapi_Dispatch = (ThreadSafe) ? NULL : dispatch;
 315 #else /*THREADS*/
 316    _glapi_Dispatch = dispatch;
 317 #endif /*THREADS*/
 318 }
 319
 320
 321
 322 /**
 323  * Return pointer to current dispatch table for calling thread.
 324  */
 325 PUBLIC struct _glapi_table *
 326 _glapi_get_dispatch(void)
 327 {
 328    struct _glapi_table * api;
 329
 330 #if defined(GLX_USE_TLS)
 331    api = _glapi_tls_Dispatch;
 332 #elif defined(THREADS)
 333    api = (ThreadSafe)
 334      ? (struct _glapi_table *) _glthread_GetTSD(&_gl_DispatchTSD)
 335      : _glapi_Dispatch;
 336 #else
 337    api = _glapi_Dispatch;
 338 #endif
 339
 340    assert( api != NULL );
 341    return api;
 342 }
 343
 344
 345 #if !defined( USE_X86_ASM ) && !defined( XFree86Server ) && !defined ( XGLServer )
 346 #define NEED_FUNCTION_POINTER
 347 #endif
 348
 349 /* The code in this file is auto-generated with Python */
 350 #include "glprocs.h"
 351
 352
 353 /**
 354  * Search the table of static entrypoint functions for the named function
 355  * and return the corresponding glprocs_table_t entry.
 356  */
 357 static const glprocs_table_t *
 358 find_entry( const char * n )
 359 {
 360    GLuint i;
 361
 362    for (i = 0; static_functions[i].Name_offset >= 0; i++) {
 363       const char * test_name;
 364
 365       test_name = gl_string_table + static_functions[i].Name_offset;
 366       if (strcmp(test_name, n) == 0) {
 367          return & static_functions[i];
 368       }
 369    }
 370    return NULL;
 371 }
 372
 373
 374 /**
 375  * Return dispatch table offset of the named static (built-in) function.
 376  * Return -1 if function not found.
 377  */
 378 static GLint
 379 get_static_proc_offset(const char *funcName)
 380 {
 381    const glprocs_table_t * const f = find_entry( funcName );
 382
 383    if ( f != NULL ) {
 384       return f->Offset;
 385    }
 386    return -1;
 387 }
 388
 389
 390 #if !defined( XFree86Server ) && !defined( XGLServer )
 391 #ifdef USE_X86_ASM
 392
 393 #if defined( GLX_USE_TLS )
 394 extern       GLubyte gl_dispatch_functions_start[];
 395 extern       GLubyte gl_dispatch_functions_end[];
 396 #else
 397 extern const GLubyte gl_dispatch_functions_start[];
 398 #endif
 399
 400 # if defined(THREADS) && !defined(GLX_USE_TLS)
 401 #  define X86_DISPATCH_FUNCTION_SIZE  32
 402 # else
 403 #  define X86_DISPATCH_FUNCTION_SIZE  16
 404 # endif
 405
 406
 407 /**
 408  * Return dispatch function address the named static (built-in) function.
 409  * Return NULL if function not found.
 410  */
 411 static const _glapi_proc
 412 get_static_proc_address(const char *funcName)
 413 {
 414    const glprocs_table_t * const f = find_entry( funcName );
 415
 416    if ( f != NULL ) {
 417       return (_glapi_proc) (gl_dispatch_functions_start
 418                             + (X86_DISPATCH_FUNCTION_SIZE * f->Offset));
 419    }
 420    else {
 421       return NULL;
 422    }
 423 }
 424
 425 #else
 426
 427
 428 /**
 429  * Return pointer to the named static (built-in) function.
 430  * \return  NULL if function not found.
 431  */
 432 static const _glapi_proc
 433 get_static_proc_address(const char *funcName)
 434 {
 435    const glprocs_table_t * const f = find_entry( funcName );
 436    return ( f != NULL ) ? f->Address : NULL;
 437 }
 438
 439 #endif /* USE_X86_ASM */
 440 #endif /* !defined( XFree86Server ) */
 441
 442
 443 /**
 444  * Return the name of the function at the given offset in the dispatch
 445  * table.  For debugging only.
 446  */
 447 static const char *
 448 get_static_proc_name( GLuint offset )
 449 {
 450    GLuint i;
 451
 452    for (i = 0; static_functions[i].Name_offset >= 0; i++) {
 453       if (static_functions[i].Offset == offset) {
 454          return gl_string_table + static_functions[i].Name_offset;
 455       }
 456    }
 457    return NULL;
 458 }
 459
 460
 461
 462 /**********************************************************************
 463  * Extension function management.
 464  */
 465
 466 /*
 467  * Number of extension functions which we can dynamically add at runtime.
 468  */
 469 #define MAX_EXTENSION_FUNCS 300
 470
 471
 472 /*
 473  * The dispatch table size (number of entries) is the size of the
 474  * _glapi_table struct plus the number of dynamic entries we can add.
 475  * The extra slots can be filled in by DRI drivers that register new extension
 476  * functions.
 477  */
 478 #define DISPATCH_TABLE_SIZE (sizeof(struct _glapi_table) / sizeof(void *) + MAX_EXTENSION_FUNCS)
 479
 480
 481 /**
 482  * Track information about a function added to the GL API.
 483  */
 484 struct _glapi_function {
 485    /**
 486     * Name of the function.
 487     */
 488    const char * name;
 489
 490
 491    /**
 492     * Text string that describes the types of the parameters passed to the
 493     * named function.   Parameter types are converted to characters using the
 494     * following rules:
 495     *   - 'i' for \c GLint, \c GLuint, and \c GLenum
 496     *   - 'p' for any pointer type
 497     *   - 'f' for \c GLfloat and \c GLclampf
 498     *   - 'd' for \c GLdouble and \c GLclampd
 499     */
 500    const char * parameter_signature;
 501
 502
 503    /**
 504     * Offset in the dispatch table where the pointer to the real function is
 505     * located.  If the driver has not requested that the named function be
 506     * added to the dispatch table, this will have the value ~0.
 507     */
 508    unsigned dispatch_offset;
 509
 510
 511    /**
 512     * Pointer to the dispatch stub for the named function.
 513     *
 514     * \todo
 515     * The semantic of this field should be changed slightly.  Currently, it
 516     * is always expected to be non-\c NULL.  However, it would be better to
 517     * only allocate the entry-point stub when the application requests the
 518     * function via \c glXGetProcAddress.  This would save memory for all the
 519     * functions that the driver exports but that the application never wants
 520     * to call.
 521     */
 522    _glapi_proc dispatch_stub;
 523 };
 524
 525
 526 static struct _glapi_function ExtEntryTable[MAX_EXTENSION_FUNCS];
 527 static GLuint NumExtEntryPoints = 0;
 528
 529 #ifdef USE_SPARC_ASM
 530 extern void __glapi_sparc_icache_flush(unsigned int *);
 531 #endif
 532
 533 /**
 534  * Generate a dispatch function (entrypoint) which jumps through
 535  * the given slot number (offset) in the current dispatch table.
 536  * We need assembly language in order to accomplish this.
 537  */
 538 static _glapi_proc
 539 generate_entrypoint(GLuint functionOffset)
 540 {
 541 #if defined(USE_X86_ASM)
 542    /* 32 is chosen as something of a magic offset.  For x86, the dispatch
 543     * at offset 32 is the first one where the offset in the
 544     * "jmp OFFSET*4(%eax)" can't be encoded in a single byte.
 545     */
 546    const GLubyte * const template_func = gl_dispatch_functions_start
 547      + (X86_DISPATCH_FUNCTION_SIZE * 32);
 548    GLubyte * const code = (GLubyte *) malloc( X86_DISPATCH_FUNCTION_SIZE );
 549
 550
 551    if ( code != NULL ) {
 552       (void) memcpy( code, template_func, X86_DISPATCH_FUNCTION_SIZE );
 553       fill_in_entrypoint_offset( (_glapi_proc) code, functionOffset );
 554    }
 555
 556    return (_glapi_proc) code;
 557 #elif defined(USE_SPARC_ASM)
 558
 559 #ifdef __arch64__
 560    static const unsigned int insn_template[] = {
 561            0x05000000,  /* sethi        %uhi(_glapi_Dispatch), %g2      */
 562            0x03000000,  /* sethi        %hi(_glapi_Dispatch), %g1       */
 563            0x8410a000,  /* or           %g2, %ulo(_glapi_Dispatch), %g2 */
 564            0x82106000,  /* or           %g1, %lo(_glapi_Dispatch), %g1  */
 565            0x8528b020,  /* sllx         %g2, 32, %g2                    */
 566            0xc2584002,  /* ldx          [%g1 + %g2], %g1                */
 567            0x05000000,  /* sethi        %hi(8 * glapioffset), %g2       */
 568            0x8410a000,  /* or           %g2, %lo(8 * glapioffset), %g2  */
 569            0xc6584002,  /* ldx          [%g1 + %g2], %g3                */
 570            0x81c0c000,  /* jmpl         %g3, %g0                        */
 571            0x01000000   /*  nop                                         */
 572    };
 573 #else
 574    static const unsigned int insn_template[] = {
 575            0x03000000,  /* sethi        %hi(_glapi_Dispatch), %g1         */
 576            0xc2006000,  /* ld           [%g1 + %lo(_glapi_Dispatch)], %g1 */
 577            0xc6006000,  /* ld           [%g1 + %lo(4*glapioffset)], %g3   */
 578            0x81c0c000,  /* jmpl         %g3, %g0                          */
 579            0x01000000   /*  nop                                           */
 580    };
 581 #endif
 582    unsigned int *code = (unsigned int *) malloc(sizeof(insn_template));
 583    unsigned long glapi_addr = (unsigned long) &_glapi_Dispatch;
 584    if (code) {
 585       memcpy(code, insn_template, sizeof(insn_template));
 586
 587 #ifdef __arch64__
 588       code[0] |= (glapi_addr >> (32 + 10));
 589       code[1] |= ((glapi_addr & 0xffffffff) >> 10);
 590       __glapi_sparc_icache_flush(&code[0]);
 591       code[2] |= ((glapi_addr >> 32) & ((1 << 10) - 1));
 592       code[3] |= (glapi_addr & ((1 << 10) - 1));
 593       __glapi_sparc_icache_flush(&code[2]);
 594       code[6] |= ((functionOffset * 8) >> 10);
 595       code[7] |= ((functionOffset * 8) & ((1 << 10) - 1));
 596       __glapi_sparc_icache_flush(&code[6]);
 597 #else
 598       code[0] |= (glapi_addr >> 10);
 599       code[1] |= (glapi_addr & ((1 << 10) - 1));
 600       __glapi_sparc_icache_flush(&code[0]);
 601       code[2] |= (functionOffset * 4);
 602       __glapi_sparc_icache_flush(&code[2]);
 603 #endif
 604    }
 605    return (_glapi_proc) code;
 606 #else
 607    (void) functionOffset;
 608    return NULL;
 609 #endif /* USE_*_ASM */
 610 }
 611
 612
 613 /**
 614  * This function inserts a new dispatch offset into the assembly language
 615  * stub that was generated with the preceeding function.
 616  */
 617 static void
 618 fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset)
 619 {
 620 #if defined(USE_X86_ASM)
 621    GLubyte * const code = (GLubyte *) entrypoint;
 622
 623
 624 #if X86_DISPATCH_FUNCTION_SIZE == 32
 625    *((unsigned int *)(code + 11)) = 4 * offset;
 626    *((unsigned int *)(code + 22)) = 4 * offset;
 627 #elif X86_DISPATCH_FUNCTION_SIZE == 16 && defined( GLX_USE_TLS )
 628    *((unsigned int *)(code +  8)) = 4 * offset;
 629 #elif X86_DISPATCH_FUNCTION_SIZE == 16
 630    *((unsigned int *)(code +  7)) = 4 * offset;
 631 #else
 632 # error Invalid X86_DISPATCH_FUNCTION_SIZE!
 633 #endif
 634
 635 #elif defined(USE_SPARC_ASM)
 636
 637    /* XXX this hasn't been tested! */
 638    unsigned int *code = (unsigned int *) entrypoint;
 639 #ifdef __arch64__
 640    code[6] = 0x05000000;  /* sethi      %hi(8 * glapioffset), %g2       */
 641    code[7] = 0x8410a000;  /* or         %g2, %lo(8 * glapioffset), %g2  */
 642    code[6] |= ((offset * 8) >> 10);
 643    code[7] |= ((offset * 8) & ((1 << 10) - 1));
 644    __glapi_sparc_icache_flush(&code[6]);
 645 #else /* __arch64__ */
 646    code[2] = 0xc6006000;  /* ld         [%g1 + %lo(4*glapioffset)], %g3   */
 647    code[2] |= (offset * 4);
 648    __glapi_sparc_icache_flush(&code[2]);
 649 #endif /* __arch64__ */
 650
 651 #else
 652
 653    /* an unimplemented architecture */
 654    (void) entrypoint;
 655    (void) offset;
 656
 657 #endif /* USE_*_ASM */
 658 }
 659
 660
 661 /**
 662  * Generate new entrypoint
 663  *
 664  * Use a temporary dispatch offset of ~0 (i.e. -1).  Later, when the driver
 665  * calls \c _glapi_add_dispatch we'll put in the proper offset.  If that
 666  * never happens, and the user calls this function, he'll segfault.  That's
 667  * what you get when you try calling a GL function that doesn't really exist.
 668  *
 669  * \param funcName  Name of the function to create an entry-point for.
 670  *
 671  * \sa _glapi_add_entrypoint
 672  */
 673
 674 static struct _glapi_function *
 675 add_function_name( const char * funcName )
 676 {
 677    struct _glapi_function * entry = NULL;
 678
 679    if (NumExtEntryPoints < MAX_EXTENSION_FUNCS) {
 680       _glapi_proc entrypoint = generate_entrypoint(~0);
 681       if (entrypoint != NULL) {
 682          entry = & ExtEntryTable[NumExtEntryPoints];
 683
 684          ExtEntryTable[NumExtEntryPoints].name = str_dup(funcName);
 685          ExtEntryTable[NumExtEntryPoints].parameter_signature = NULL;
 686          ExtEntryTable[NumExtEntryPoints].dispatch_offset = ~0;
 687          ExtEntryTable[NumExtEntryPoints].dispatch_stub = entrypoint;
 688          NumExtEntryPoints++;
 689       }
 690    }
 691
 692    return entry;
 693 }
 694
 695
 696 /**
 697  * Fill-in the dispatch stub for the named function.
 698  *
 699  * This function is intended to be called by a hardware driver.  When called,
 700  * a dispatch stub may be created created for the function.  A pointer to this
 701  * dispatch function will be returned by glXGetProcAddress.
 702  *
 703  * \param function_names       Array of pointers to function names that should
 704  *                             share a common dispatch offset.
 705  * \param parameter_signature  String representing the types of the parameters
 706  *                             passed to the named function.  Parameter types
 707  *                             are converted to characters using the following
 708  *                             rules:
 709  *                               - 'i' for \c GLint, \c GLuint, and \c GLenum
 710  *                               - 'p' for any pointer type
 711  *                               - 'f' for \c GLfloat and \c GLclampf
 712  *                               - 'd' for \c GLdouble and \c GLclampd
 713  *
 714  * \returns
 715  * The offset in the dispatch table of the named function.  A pointer to the
 716  * driver's implementation of the named function should be stored at
 717  * \c dispatch_table[\c offset].
 718  *
 719  * \sa glXGetProcAddress
 720  *
 721  * \warning
 722  * This function can only handle up to 8 names at a time.  As far as I know,
 723  * the maximum number of names ever associated with an existing GL function is
 724  * 4 (\c glPointParameterfSGIS, \c glPointParameterfEXT,
 725  * \c glPointParameterfARB, and \c glPointParameterf), so this should not be
 726  * too painful of a limitation.
 727  *
 728  * \todo
 729  * Determine whether or not \c parameter_signature should be allowed to be
 730  * \c NULL.  It doesn't seem like much of a hardship for drivers to have to
 731  * pass in an empty string.
 732  *
 733  * \todo
 734  * Determine if code should be added to reject function names that start with
 735  * 'glX'.
 736  *
 737  * \bug
 738  * Add code to compare \c parameter_signature with the parameter signature of
 739  * a static function.  In order to do that, we need to find a way to \b get
 740  * the parameter signature of a static function.
 741  */
 742
 743 PUBLIC int
 744 _glapi_add_dispatch( const char * const * function_names,
 745                      const char * parameter_signature )
 746 {
 747    static int next_dynamic_offset = _gloffset_FIRST_DYNAMIC;
 748    const char * const real_sig = (parameter_signature != NULL)
 749      ? parameter_signature : "";
 750    struct _glapi_function * entry[8];
 751    GLboolean is_static[8];
 752    unsigned i;
 753    unsigned j;
 754    int offset = ~0;
 755    int new_offset;
 756
 757
 758    (void) memset( is_static, 0, sizeof( is_static ) );
 759    (void) memset( entry, 0, sizeof( entry ) );
 760
 761    for ( i = 0 ; function_names[i] != NULL ; i++ ) {
 762       /* Do some trivial validation on the name of the function.
 763        */
 764
 765       if (!function_names[i] || function_names[i][0] != 'g' || function_names[i][1] != 'l')
 766         return GL_FALSE;
 767
 768       /* Determine if the named function already exists.  If the function does
 769        * exist, it must have the same parameter signature as the function
 770        * being added.
 771        */
 772
 773       new_offset = get_static_proc_offset(function_names[i]);
 774       if (new_offset >= 0) {
 775          /* FIXME: Make sure the parameter signatures match!  How do we get
 776           * FIXME: the parameter signature for static functions?
 777           */
 778
 779          if ( (offset != ~0) && (new_offset != offset) ) {
 780             return -1;
 781          }
 782
 783          is_static[i] = GL_TRUE;
 784          offset = new_offset;
 785       }
 786
 787
 788       for ( j = 0 ; j < NumExtEntryPoints ; j++ ) {
 789          if (strcmp(ExtEntryTable[j].name, function_names[i]) == 0) {
 790             /* The offset may be ~0 if the function name was added by
 791              * glXGetProcAddress but never filled in by the driver.
 792              */
 793
 794             if (ExtEntryTable[j].dispatch_offset != ~0) {
 795                if (strcmp(real_sig, ExtEntryTable[j].parameter_signature)
 796                    != 0) {
 797                   return -1;
 798                }
 799
 800                if ( (offset != ~0) && (ExtEntryTable[j].dispatch_offset != offset) ) {
 801                   return -1;
 802                }
 803
 804                offset = ExtEntryTable[j].dispatch_offset;
 805             }
 806
 807             entry[i] = & ExtEntryTable[j];
 808             break;
 809          }
 810       }
 811    }
 812
 813
 814    if (offset == ~0) {
 815       offset = next_dynamic_offset;
 816       next_dynamic_offset++;
 817    }
 818
 819
 820    for ( i = 0 ; function_names[i] != NULL ; i++ ) {
 821       if (! is_static[i] ) {
 822          if (entry[i] == NULL) {
 823             entry[i] = add_function_name( function_names[i] );
 824             if (entry[i] == NULL) {
 825                /* FIXME: Possible memory leak here.
 826                 */
 827                return -1;
 828             }
 829          }
 830
 831
 832          entry[i]->parameter_signature = str_dup(real_sig);
 833          fill_in_entrypoint_offset(entry[i]->dispatch_stub, offset);
 834          entry[i]->dispatch_offset = offset;
 835       }
 836    }
 837
 838    return offset;
 839 }
 840
 841
 842 /**
 843  * Return offset of entrypoint for named function within dispatch table.
 844  */
 845 PUBLIC GLint
 846 _glapi_get_proc_offset(const char *funcName)
 847 {
 848    /* search extension functions first */
 849    GLuint i;
 850    for (i = 0; i < NumExtEntryPoints; i++) {
 851       if (strcmp(ExtEntryTable[i].name, funcName) == 0) {
 852          return ExtEntryTable[i].dispatch_offset;
 853       }
 854    }
 855
 856    /* search static functions */
 857    return get_static_proc_offset(funcName);
 858 }
 859
 860
 861
 862 /**
 863  * Return pointer to the named function.  If the function name isn't found
 864  * in the name of static functions, try generating a new API entrypoint on
 865  * the fly with assembly language.
 866  */
 867 _glapi_proc
 868 _glapi_get_proc_address(const char *funcName)
 869 {
 870    struct _glapi_function * entry;
 871    GLuint i;
 872
 873 #ifdef MANGLE
 874    if (funcName[0] != 'm' || funcName[1] != 'g' || funcName[2] != 'l')
 875       return NULL;
 876 #else
 877    if (funcName[0] != 'g' || funcName[1] != 'l')
 878       return NULL;
 879 #endif
 880
 881    /* search extension functions first */
 882    for (i = 0; i < NumExtEntryPoints; i++) {
 883       if (strcmp(ExtEntryTable[i].name, funcName) == 0) {
 884          return ExtEntryTable[i].dispatch_stub;
 885       }
 886    }
 887
 888 #if !defined( XFree86Server ) && !defined( XGLServer )
 889    /* search static functions */
 890    {
 891       const _glapi_proc func = get_static_proc_address(funcName);
 892       if (func)
 893          return func;
 894    }
 895 #endif /* !defined( XFree86Server ) */
 896
 897    entry = add_function_name(funcName);
 898    return (entry == NULL) ? NULL : entry->dispatch_stub;
 899 }
 900
 901
 902
 903 /**
 904  * Return the name of the function at the given dispatch offset.
 905  * This is only intended for debugging.
 906  */
 907 const char *
 908 _glapi_get_proc_name(GLuint offset)
 909 {
 910    GLuint i;
 911    const char * n;
 912
 913    /* search built-in functions */
 914    n = get_static_proc_name(offset);
 915    if ( n != NULL ) {
 916       return n;
 917    }
 918
 919    /* search added extension functions */
 920    for (i = 0; i < NumExtEntryPoints; i++) {
 921       if (ExtEntryTable[i].dispatch_offset == offset) {
 922          return ExtEntryTable[i].name;
 923       }
 924    }
 925    return NULL;
 926 }
 927
 928
 929
 930 /**
 931  * Return size of dispatch table struct as number of functions (or
 932  * slots).
 933  */
 934 PUBLIC GLuint
 935 _glapi_get_dispatch_table_size(void)
 936 {
 937    return DISPATCH_TABLE_SIZE;
 938 }
 939
 940
 941
 942 /**
 943  * Make sure there are no NULL pointers in the given dispatch table.
 944  * Intended for debugging purposes.
 945  */
 946 void
 947 _glapi_check_table(const struct _glapi_table *table)
 948 {
 949 #ifdef DEBUG
 950    const GLuint entries = _glapi_get_dispatch_table_size();
 951    const void **tab = (const void **) table;
 952    GLuint i;
 953    for (i = 1; i < entries; i++) {
 954       assert(tab[i]);
 955    }
 956
 957    /* Do some spot checks to be sure that the dispatch table
 958     * slots are assigned correctly.
 959     */
 960    {
 961       GLuint BeginOffset = _glapi_get_proc_offset("glBegin");
 962       char *BeginFunc = (char*) &table->Begin;
 963       GLuint offset = (BeginFunc - (char *) table) / sizeof(void *);
 964       assert(BeginOffset == _gloffset_Begin);
 965       assert(BeginOffset == offset);
 966    }
 967    {
 968       GLuint viewportOffset = _glapi_get_proc_offset("glViewport");
 969       char *viewportFunc = (char*) &table->Viewport;
 970       GLuint offset = (viewportFunc - (char *) table) / sizeof(void *);
 971       assert(viewportOffset == _gloffset_Viewport);
 972       assert(viewportOffset == offset);
 973    }
 974    {
 975       GLuint VertexPointerOffset = _glapi_get_proc_offset("glVertexPointer");
 976       char *VertexPointerFunc = (char*) &table->VertexPointer;
 977       GLuint offset = (VertexPointerFunc - (char *) table) / sizeof(void *);
 978       assert(VertexPointerOffset == _gloffset_VertexPointer);
 979       assert(VertexPointerOffset == offset);
 980    }
 981    {
 982       GLuint ResetMinMaxOffset = _glapi_get_proc_offset("glResetMinmax");
 983       char *ResetMinMaxFunc = (char*) &table->ResetMinmax;
 984       GLuint offset = (ResetMinMaxFunc - (char *) table) / sizeof(void *);
 985       assert(ResetMinMaxOffset == _gloffset_ResetMinmax);
 986       assert(ResetMinMaxOffset == offset);
 987    }
 988    {
 989       GLuint blendColorOffset = _glapi_get_proc_offset("glBlendColor");
 990       char *blendColorFunc = (char*) &table->BlendColor;
 991       GLuint offset = (blendColorFunc - (char *) table) / sizeof(void *);
 992       assert(blendColorOffset == _gloffset_BlendColor);
 993       assert(blendColorOffset == offset);
 994    }
 995    {
 996       GLuint istextureOffset = _glapi_get_proc_offset("glIsTextureEXT");
 997       char *istextureFunc = (char*) &table->IsTextureEXT;
 998       GLuint offset = (istextureFunc - (char *) table) / sizeof(void *);
 999       assert(istextureOffset == _gloffset_IsTextureEXT);
1000       assert(istextureOffset == offset);
1001    }
1002    {
1003       GLuint secondaryColor3fOffset = _glapi_get_proc_offset("glSecondaryColor3fEXT");
1004       char *secondaryColor3fFunc = (char*) &table->SecondaryColor3fEXT;
1005       GLuint offset = (secondaryColor3fFunc - (char *) table) / sizeof(void *);
1006       assert(secondaryColor3fOffset == _gloffset_SecondaryColor3fEXT);
1007       assert(secondaryColor3fOffset == offset);
1008       assert(_glapi_get_proc_address("glSecondaryColor3fEXT") == (_glapi_proc) &glSecondaryColor3fEXT);
1009    }
1010    {
1011       GLuint pointParameterivOffset = _glapi_get_proc_offset("glPointParameterivNV");
1012       char *pointParameterivFunc = (char*) &table->PointParameterivNV;
1013       GLuint offset = (pointParameterivFunc - (char *) table) / sizeof(void *);
1014       assert(pointParameterivOffset == _gloffset_PointParameterivNV);
1015       assert(pointParameterivOffset == offset);
1016       assert(_glapi_get_proc_address("glPointParameterivNV") == (_glapi_proc) &glPointParameterivNV);
1017    }
1018    {
1019       GLuint setFenceOffset = _glapi_get_proc_offset("glSetFenceNV");
1020       char *setFenceFunc = (char*) &table->SetFenceNV;
1021       GLuint offset = (setFenceFunc - (char *) table) / sizeof(void *);
1022       assert(setFenceOffset == _gloffset_SetFenceNV);
1023       assert(setFenceOffset == offset);
1024       assert(_glapi_get_proc_address("glSetFenceNV") == (_glapi_proc) &glSetFenceNV);
1025    }
1026 #else
1027    (void) table;
1028 #endif
1029 }
1030
1031
1032 /**
1033  * Perform platform-specific GL API entry-point fixups.
1034  *
1035  *
1036  */
1037 static void
1038 init_glapi_relocs( void )
1039 {
1040 #if defined( USE_X86_ASM ) && defined( GLX_USE_TLS )
1041     extern void * _x86_get_dispatch(void);
1042     const GLubyte * const get_disp = (const GLubyte *) _x86_get_dispatch;
1043     GLubyte * curr_func = (GLubyte *) gl_dispatch_functions_start;
1044
1045
1046     while ( curr_func != (GLubyte *) gl_dispatch_functions_end ) {
1047         (void) memcpy( curr_func, get_disp, 6 );
1048         curr_func += X86_DISPATCH_FUNCTION_SIZE;
1049     }
1050 #endif /* defined( USE_X86_ASM ) && defined( GLX_USE_TLS ) */
1051 }