src/mesa/glapi/glapi.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5
   4  *
   5  * Copyright (C) 1999-2006  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 "glheader.h"
  61
  62 #endif
  63
  64 #include <stdlib.h>
  65 #include <string.h>
  66 #ifdef DEBUG
  67 #include <assert.h>
  68 #endif
  69
  70 #include "glapi.h"
  71 #include "glapioffsets.h"
  72 #include "glapitable.h"
  73
  74 /***** BEGIN NO-OP DISPATCH *****/
  75
  76 static GLboolean WarnFlag = GL_FALSE;
  77 static _glapi_warning_func warning_func;
  78
  79 #if defined(PTHREADS) || defined(GLX_USE_TLS)
  80 static void init_glapi_relocs(void);
  81 #endif
  82
  83 static _glapi_proc generate_entrypoint(GLuint functionOffset);
  84 static void fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset);
  85
  86 /*
  87  * Enable/disable printing of warning messages.
  88  */
  89 PUBLIC void
  90 _glapi_noop_enable_warnings(GLboolean enable)
  91 {
  92    WarnFlag = enable;
  93 }
  94
  95 /*
  96  * Register a callback function for reporting errors.
  97  */
  98 PUBLIC void
  99 _glapi_set_warning_func( _glapi_warning_func func )
 100 {
 101    warning_func = func;
 102 }
 103
 104 static GLboolean
 105 warn(void)
 106 {
 107    if ((WarnFlag || getenv("MESA_DEBUG") || getenv("LIBGL_DEBUG"))
 108        && warning_func) {
 109       return GL_TRUE;
 110    }
 111    else {
 112       return GL_FALSE;
 113    }
 114 }
 115
 116
 117 #define KEYWORD1 static
 118 #define KEYWORD1_ALT static
 119 #define KEYWORD2 GLAPIENTRY
 120 #define NAME(func)  NoOp##func
 121
 122 #define F NULL
 123
 124 #define DISPATCH(func, args, msg)                                             \
 125    if (warn()) {                                                              \
 126       warning_func(NULL, "GL User Error: called without context: %s", #func); \
 127    }
 128
 129 #define RETURN_DISPATCH(func, args, msg)                                      \
 130    if (warn()) {                                                              \
 131       warning_func(NULL, "GL User Error: called without context: %s", #func); \
 132    }                                                                          \
 133    return 0
 134
 135 #define DISPATCH_TABLE_NAME __glapi_noop_table
 136 #define UNUSED_TABLE_NAME __unused_noop_functions
 137
 138 #define TABLE_ENTRY(name) (_glapi_proc) NoOp##name
 139
 140 static GLint NoOpUnused(void)
 141 {
 142    if (warn()) {
 143       warning_func(NULL, "GL User Error: calling extension function without a current context\n");
 144    }
 145    return 0;
 146 }
 147
 148 #include "glapitemp.h"
 149
 150 /***** END NO-OP DISPATCH *****/
 151
 152
 153
 154 /**
 155  * \name Current dispatch and current context control variables
 156  *
 157  * Depending on whether or not multithreading is support, and the type of
 158  * support available, several variables are used to store the current context
 159  * pointer and the current dispatch table pointer.  In the non-threaded case,
 160  * the variables \c _glapi_Dispatch and \c _glapi_Context are used for this
 161  * purpose.
 162  *
 163  * In the "normal" threaded case, the variables \c _glapi_Dispatch and
 164  * \c _glapi_Context will be \c NULL if an application is detected as being
 165  * multithreaded.  Single-threaded applications will use \c _glapi_Dispatch
 166  * and \c _glapi_Context just like the case without any threading support.
 167  * When \c _glapi_Dispatch and \c _glapi_Context are \c NULL, the thread state
 168  * data \c _gl_DispatchTSD and \c ContextTSD are used.  Drivers and the
 169  * static dispatch functions access these variables via \c _glapi_get_dispatch
 170  * and \c _glapi_get_context.
 171  *
 172  * There is a race condition in setting \c _glapi_Dispatch to \c NULL.  It is
 173  * possible for the original thread to be setting it at the same instant a new
 174  * thread, perhaps running on a different processor, is clearing it.  Because
 175  * of that, \c ThreadSafe, which can only ever be changed to \c GL_TRUE, is
 176  * used to determine whether or not the application is multithreaded.
 177  *
 178  * In the TLS case, the variables \c _glapi_Dispatch and \c _glapi_Context are
 179  * hardcoded to \c NULL.  Instead the TLS variables \c _glapi_tls_Dispatch and
 180  * \c _glapi_tls_Context are used.  Having \c _glapi_Dispatch and
 181  * \c _glapi_Context be hardcoded to \c NULL maintains binary compatability
 182  * between TLS enabled loaders and non-TLS DRI drivers.
 183  */
 184 /*@{*/
 185 #if defined(GLX_USE_TLS)
 186
 187 PUBLIC __thread struct _glapi_table * _glapi_tls_Dispatch
 188     __attribute__((tls_model("initial-exec")))
 189     = (struct _glapi_table *) __glapi_noop_table;
 190
 191 PUBLIC __thread void * _glapi_tls_Context
 192     __attribute__((tls_model("initial-exec")));
 193
 194 PUBLIC const struct _glapi_table *_glapi_Dispatch = NULL;
 195 PUBLIC const void *_glapi_Context = NULL;
 196
 197 #else
 198
 199 #if defined(THREADS)
 200
 201 static GLboolean ThreadSafe = GL_FALSE;  /**< In thread-safe mode? */
 202 _glthread_TSD _gl_DispatchTSD;           /**< Per-thread dispatch pointer */
 203 static _glthread_TSD ContextTSD;         /**< Per-thread context pointer */
 204
 205 #if defined(WIN32_THREADS)
 206 void FreeTSD(_glthread_TSD *p);
 207 void FreeAllTSD(void)
 208 {
 209    FreeTSD(&_gl_DispatchTSD);
 210    FreeTSD(&ContextTSD);
 211 }
 212 #endif /* defined(WIN32_THREADS) */
 213
 214 #endif /* defined(THREADS) */
 215
 216 PUBLIC struct _glapi_table *_glapi_Dispatch =
 217   (struct _glapi_table *) __glapi_noop_table;
 218 PUBLIC void *_glapi_Context = NULL;
 219
 220 #endif /* defined(GLX_USE_TLS) */
 221 /*@}*/
 222
 223
 224 /**
 225  * strdup() is actually not a standard ANSI C or POSIX routine.
 226  * Irix will not define it if ANSI mode is in effect.
 227  */
 228 static char *
 229 str_dup(const char *str)
 230 {
 231    char *copy;
 232    copy = (char*) malloc(strlen(str) + 1);
 233    if (!copy)
 234       return NULL;
 235    strcpy(copy, str);
 236    return copy;
 237 }
 238
 239
 240
 241 /**
 242  * We should call this periodically from a function such as glXMakeCurrent
 243  * in order to test if multiple threads are being used.
 244  */
 245 void
 246 _glapi_check_multithread(void)
 247 {
 248 #if defined(THREADS) && !defined(GLX_USE_TLS)
 249    if (!ThreadSafe) {
 250       static unsigned long knownID;
 251       static GLboolean firstCall = GL_TRUE;
 252       if (firstCall) {
 253          knownID = _glthread_GetID();
 254          firstCall = GL_FALSE;
 255       }
 256       else if (knownID != _glthread_GetID()) {
 257          ThreadSafe = GL_TRUE;
 258          _glapi_set_dispatch(NULL);
 259          _glapi_set_context(NULL);
 260       }
 261    }
 262    else if (!_glapi_get_dispatch()) {
 263       /* make sure that this thread's dispatch pointer isn't null */
 264       _glapi_set_dispatch(NULL);
 265    }
 266 #endif
 267 }
 268
 269
 270
 271 /**
 272  * Set the current context pointer for this thread.
 273  * The context pointer is an opaque type which should be cast to
 274  * void from the real context pointer type.
 275  */
 276 PUBLIC void
 277 _glapi_set_context(void *context)
 278 {
 279    (void) __unused_noop_functions; /* silence a warning */
 280 #if defined(GLX_USE_TLS)
 281    _glapi_tls_Context = context;
 282 #elif defined(THREADS)
 283    _glthread_SetTSD(&ContextTSD, context);
 284    _glapi_Context = (ThreadSafe) ? NULL : context;
 285 #else
 286    _glapi_Context = context;
 287 #endif
 288 }
 289
 290
 291
 292 /**
 293  * Get the current context pointer for this thread.
 294  * The context pointer is an opaque type which should be cast from
 295  * void to the real context pointer type.
 296  */
 297 PUBLIC void *
 298 _glapi_get_context(void)
 299 {
 300 #if defined(GLX_USE_TLS)
 301    return _glapi_tls_Context;
 302 #elif defined(THREADS)
 303    if (ThreadSafe) {
 304       return _glthread_GetTSD(&ContextTSD);
 305    }
 306    else {
 307       return _glapi_Context;
 308    }
 309 #else
 310    return _glapi_Context;
 311 #endif
 312 }
 313
 314
 315
 316 /**
 317  * Set the global or per-thread dispatch table pointer.
 318  * If the dispatch parameter is NULL we'll plug in the no-op dispatch
 319  * table (__glapi_noop_table).
 320  */
 321 PUBLIC void
 322 _glapi_set_dispatch(struct _glapi_table *dispatch)
 323 {
 324 #if defined(PTHREADS) || defined(GLX_USE_TLS)
 325    static pthread_once_t once_control = PTHREAD_ONCE_INIT;
 326    pthread_once( & once_control, init_glapi_relocs );
 327 #endif
 328
 329    if (!dispatch) {
 330       /* use the no-op functions */
 331       dispatch = (struct _glapi_table *) __glapi_noop_table;
 332    }
 333 #ifdef DEBUG
 334    else {
 335       _glapi_check_table(dispatch);
 336    }
 337 #endif
 338
 339 #if defined(GLX_USE_TLS)
 340    _glapi_tls_Dispatch = dispatch;
 341 #elif defined(THREADS)
 342    _glthread_SetTSD(&_gl_DispatchTSD, (void *) dispatch);
 343    _glapi_Dispatch = (ThreadSafe) ? NULL : dispatch;
 344 #else /*THREADS*/
 345    _glapi_Dispatch = dispatch;
 346 #endif /*THREADS*/
 347 }
 348
 349
 350
 351 /**
 352  * Return pointer to current dispatch table for calling thread.
 353  */
 354 PUBLIC struct _glapi_table *
 355 _glapi_get_dispatch(void)
 356 {
 357    struct _glapi_table * api;
 358 #if defined(GLX_USE_TLS)
 359    api = _glapi_tls_Dispatch;
 360 #elif defined(THREADS)
 361    api = (ThreadSafe)
 362      ? (struct _glapi_table *) _glthread_GetTSD(&_gl_DispatchTSD)
 363      : _glapi_Dispatch;
 364 #else
 365    api = _glapi_Dispatch;
 366 #endif
 367    return api;
 368 }
 369
 370
 371
 372 /***
 373  *** The rest of this file is pretty much concerned with GetProcAddress
 374  *** functionality.
 375  ***/
 376
 377 #if defined(USE_X64_64_ASM) && defined(GLX_USE_TLS)
 378 # define DISPATCH_FUNCTION_SIZE  16
 379 #elif defined(USE_X86_ASM)
 380 # if defined(THREADS) && !defined(GLX_USE_TLS)
 381 #  define DISPATCH_FUNCTION_SIZE  32
 382 # else
 383 #  define DISPATCH_FUNCTION_SIZE  16
 384 # endif
 385 #endif
 386
 387 #if !defined(DISPATCH_FUNCTION_SIZE) && !defined(XFree86Server) && !defined(XGLServer)
 388 # define NEED_FUNCTION_POINTER
 389 #endif
 390
 391 /* The code in this file is auto-generated with Python */
 392 #include "glprocs.h"
 393
 394
 395 /**
 396  * Search the table of static entrypoint functions for the named function
 397  * and return the corresponding glprocs_table_t entry.
 398  */
 399 static const glprocs_table_t *
 400 find_entry( const char * n )
 401 {
 402    GLuint i;
 403    for (i = 0; static_functions[i].Name_offset >= 0; i++) {
 404       const char *testName = gl_string_table + static_functions[i].Name_offset;
 405       if (strcmp(testName, n) == 0) {
 406          return &static_functions[i];
 407       }
 408    }
 409    return NULL;
 410 }
 411
 412
 413 /**
 414  * Return dispatch table offset of the named static (built-in) function.
 415  * Return -1 if function not found.
 416  */
 417 static GLint
 418 get_static_proc_offset(const char *funcName)
 419 {
 420    const glprocs_table_t * const f = find_entry( funcName );
 421    if (f) {
 422       return f->Offset;
 423    }
 424    return -1;
 425 }
 426
 427
 428 #if !defined(XFree86Server) && !defined(XGLServer)
 429 #ifdef USE_X86_ASM
 430
 431 #if defined( GLX_USE_TLS )
 432 extern       GLubyte gl_dispatch_functions_start[];
 433 extern       GLubyte gl_dispatch_functions_end[];
 434 #else
 435 extern const GLubyte gl_dispatch_functions_start[];
 436 #endif
 437
 438 #endif /* USE_X86_ASM */
 439
 440
 441 /**
 442  * Return dispatch function address for the named static (built-in) function.
 443  * Return NULL if function not found.
 444  */
 445 static _glapi_proc
 446 get_static_proc_address(const char *funcName)
 447 {
 448    const glprocs_table_t * const f = find_entry( funcName );
 449    if (f) {
 450 #if defined(DISPATCH_FUNCTION_SIZE) && defined(GLX_INDIRECT_RENDERING)
 451       return (f->Address == NULL)
 452          ? (_glapi_proc) (gl_dispatch_functions_start
 453                           + (DISPATCH_FUNCTION_SIZE * f->Offset))
 454          : f->Address;
 455 #elif defined(DISPATCH_FUNCTION_SIZE)
 456       return (_glapi_proc) (gl_dispatch_functions_start
 457                             + (DISPATCH_FUNCTION_SIZE * f->Offset));
 458 #else
 459       return f->Address;
 460 #endif
 461    }
 462    else {
 463       return NULL;
 464    }
 465 }
 466
 467 #endif /* !defined(XFree86Server) && !defined(XGLServer) */
 468
 469
 470
 471 /**
 472  * Return the name of the function at the given offset in the dispatch
 473  * table.  For debugging only.
 474  */
 475 static const char *
 476 get_static_proc_name( GLuint offset )
 477 {
 478    GLuint i;
 479    for (i = 0; static_functions[i].Name_offset >= 0; i++) {
 480       if (static_functions[i].Offset == offset) {
 481          return gl_string_table + static_functions[i].Name_offset;
 482       }
 483    }
 484    return NULL;
 485 }
 486
 487
 488
 489 /**********************************************************************
 490  * Extension function management.
 491  */
 492
 493 /*
 494  * Number of extension functions which we can dynamically add at runtime.
 495  */
 496 #define MAX_EXTENSION_FUNCS 300
 497
 498
 499 /*
 500  * The dispatch table size (number of entries) is the size of the
 501  * _glapi_table struct plus the number of dynamic entries we can add.
 502  * The extra slots can be filled in by DRI drivers that register new extension
 503  * functions.
 504  */
 505 #define DISPATCH_TABLE_SIZE (sizeof(struct _glapi_table) / sizeof(void *) + MAX_EXTENSION_FUNCS)
 506
 507
 508 /**
 509  * Track information about a function added to the GL API.
 510  */
 511 struct _glapi_function {
 512    /**
 513     * Name of the function.
 514     */
 515    const char * name;
 516
 517
 518    /**
 519     * Text string that describes the types of the parameters passed to the
 520     * named function.   Parameter types are converted to characters using the
 521     * following rules:
 522     *   - 'i' for \c GLint, \c GLuint, and \c GLenum
 523     *   - 'p' for any pointer type
 524     *   - 'f' for \c GLfloat and \c GLclampf
 525     *   - 'd' for \c GLdouble and \c GLclampd
 526     */
 527    const char * parameter_signature;
 528
 529
 530    /**
 531     * Offset in the dispatch table where the pointer to the real function is
 532     * located.  If the driver has not requested that the named function be
 533     * added to the dispatch table, this will have the value ~0.
 534     */
 535    unsigned dispatch_offset;
 536
 537
 538    /**
 539     * Pointer to the dispatch stub for the named function.
 540     *
 541     * \todo
 542     * The semantic of this field should be changed slightly.  Currently, it
 543     * is always expected to be non-\c NULL.  However, it would be better to
 544     * only allocate the entry-point stub when the application requests the
 545     * function via \c glXGetProcAddress.  This would save memory for all the
 546     * functions that the driver exports but that the application never wants
 547     * to call.
 548     */
 549    _glapi_proc dispatch_stub;
 550 };
 551
 552
 553 static struct _glapi_function ExtEntryTable[MAX_EXTENSION_FUNCS];
 554 static GLuint NumExtEntryPoints = 0;
 555
 556 #ifdef USE_SPARC_ASM
 557 extern void __glapi_sparc_icache_flush(unsigned int *);
 558 #endif
 559
 560 /**
 561  * Generate a dispatch function (entrypoint) which jumps through
 562  * the given slot number (offset) in the current dispatch table.
 563  * We need assembly language in order to accomplish this.
 564  */
 565 static _glapi_proc
 566 generate_entrypoint(GLuint functionOffset)
 567 {
 568 #if defined(USE_X86_ASM)
 569    /* 32 is chosen as something of a magic offset.  For x86, the dispatch
 570     * at offset 32 is the first one where the offset in the
 571     * "jmp OFFSET*4(%eax)" can't be encoded in a single byte.
 572     */
 573    const GLubyte * const template_func = gl_dispatch_functions_start
 574      + (DISPATCH_FUNCTION_SIZE * 32);
 575    GLubyte * const code = (GLubyte *) malloc(DISPATCH_FUNCTION_SIZE);
 576
 577
 578    if ( code != NULL ) {
 579       (void) memcpy(code, template_func, DISPATCH_FUNCTION_SIZE);
 580       fill_in_entrypoint_offset( (_glapi_proc) code, functionOffset );
 581    }
 582
 583    return (_glapi_proc) code;
 584 #elif defined(USE_SPARC_ASM)
 585
 586 #ifdef __arch64__
 587    static const unsigned int insn_template[] = {
 588            0x05000000,  /* sethi        %uhi(_glapi_Dispatch), %g2      */
 589            0x03000000,  /* sethi        %hi(_glapi_Dispatch), %g1       */
 590            0x8410a000,  /* or           %g2, %ulo(_glapi_Dispatch), %g2 */
 591            0x82106000,  /* or           %g1, %lo(_glapi_Dispatch), %g1  */
 592            0x8528b020,  /* sllx         %g2, 32, %g2                    */
 593            0xc2584002,  /* ldx          [%g1 + %g2], %g1                */
 594            0x05000000,  /* sethi        %hi(8 * glapioffset), %g2       */
 595            0x8410a000,  /* or           %g2, %lo(8 * glapioffset), %g2  */
 596            0xc6584002,  /* ldx          [%g1 + %g2], %g3                */
 597            0x81c0c000,  /* jmpl         %g3, %g0                        */
 598            0x01000000   /*  nop                                         */
 599    };
 600 #else
 601    static const unsigned int insn_template[] = {
 602            0x03000000,  /* sethi        %hi(_glapi_Dispatch), %g1         */
 603            0xc2006000,  /* ld           [%g1 + %lo(_glapi_Dispatch)], %g1 */
 604            0xc6006000,  /* ld           [%g1 + %lo(4*glapioffset)], %g3   */
 605            0x81c0c000,  /* jmpl         %g3, %g0                          */
 606            0x01000000   /*  nop                                           */
 607    };
 608 #endif /* __arch64__ */
 609    unsigned int *code = (unsigned int *) malloc(sizeof(insn_template));
 610    unsigned long glapi_addr = (unsigned long) &_glapi_Dispatch;
 611    if (code) {
 612       memcpy(code, insn_template, sizeof(insn_template));
 613
 614 #ifdef __arch64__
 615       code[0] |= (glapi_addr >> (32 + 10));
 616       code[1] |= ((glapi_addr & 0xffffffff) >> 10);
 617       __glapi_sparc_icache_flush(&code[0]);
 618       code[2] |= ((glapi_addr >> 32) & ((1 << 10) - 1));
 619       code[3] |= (glapi_addr & ((1 << 10) - 1));
 620       __glapi_sparc_icache_flush(&code[2]);
 621       code[6] |= ((functionOffset * 8) >> 10);
 622       code[7] |= ((functionOffset * 8) & ((1 << 10) - 1));
 623       __glapi_sparc_icache_flush(&code[6]);
 624 #else
 625       code[0] |= (glapi_addr >> 10);
 626       code[1] |= (glapi_addr & ((1 << 10) - 1));
 627       __glapi_sparc_icache_flush(&code[0]);
 628       code[2] |= (functionOffset * 4);
 629       __glapi_sparc_icache_flush(&code[2]);
 630 #endif /* __arch64__ */
 631    }
 632    return (_glapi_proc) code;
 633 #else
 634    (void) functionOffset;
 635    return NULL;
 636 #endif /* USE_*_ASM */
 637 }
 638
 639
 640 /**
 641  * This function inserts a new dispatch offset into the assembly language
 642  * stub that was generated with the preceeding function.
 643  */
 644 static void
 645 fill_in_entrypoint_offset(_glapi_proc entrypoint, GLuint offset)
 646 {
 647 #if defined(USE_X86_ASM)
 648    GLubyte * const code = (GLubyte *) entrypoint;
 649
 650 #if DISPATCH_FUNCTION_SIZE == 32
 651    *((unsigned int *)(code + 11)) = 4 * offset;
 652    *((unsigned int *)(code + 22)) = 4 * offset;
 653 #elif DISPATCH_FUNCTION_SIZE == 16 && defined( GLX_USE_TLS )
 654    *((unsigned int *)(code +  8)) = 4 * offset;
 655 #elif DISPATCH_FUNCTION_SIZE == 16
 656    *((unsigned int *)(code +  7)) = 4 * offset;
 657 #else
 658 # error Invalid DISPATCH_FUNCTION_SIZE!
 659 #endif
 660
 661 #elif defined(USE_SPARC_ASM)
 662
 663    /* XXX this hasn't been tested! */
 664    unsigned int *code = (unsigned int *) entrypoint;
 665 #ifdef __arch64__
 666    code[6] = 0x05000000;  /* sethi      %hi(8 * glapioffset), %g2       */
 667    code[7] = 0x8410a000;  /* or         %g2, %lo(8 * glapioffset), %g2  */
 668    code[6] |= ((offset * 8) >> 10);
 669    code[7] |= ((offset * 8) & ((1 << 10) - 1));
 670    __glapi_sparc_icache_flush(&code[6]);
 671 #else /* __arch64__ */
 672    code[2] = 0xc6006000;  /* ld         [%g1 + %lo(4*glapioffset)], %g3   */
 673    code[2] |= (offset * 4);
 674    __glapi_sparc_icache_flush(&code[2]);
 675 #endif /* __arch64__ */
 676
 677 #else
 678
 679    /* an unimplemented architecture */
 680    (void) entrypoint;
 681    (void) offset;
 682
 683 #endif /* USE_*_ASM */
 684 }
 685
 686
 687 /**
 688  * Generate new entrypoint
 689  *
 690  * Use a temporary dispatch offset of ~0 (i.e. -1).  Later, when the driver
 691  * calls \c _glapi_add_dispatch we'll put in the proper offset.  If that
 692  * never happens, and the user calls this function, he'll segfault.  That's
 693  * what you get when you try calling a GL function that doesn't really exist.
 694  *
 695  * \param funcName  Name of the function to create an entry-point for.
 696  *
 697  * \sa _glapi_add_entrypoint
 698  */
 699
 700 static struct _glapi_function *
 701 add_function_name( const char * funcName )
 702 {
 703    struct _glapi_function * entry = NULL;
 704
 705    if (NumExtEntryPoints < MAX_EXTENSION_FUNCS) {
 706       _glapi_proc entrypoint = generate_entrypoint(~0);
 707       if (entrypoint != NULL) {
 708          entry = & ExtEntryTable[NumExtEntryPoints];
 709
 710          ExtEntryTable[NumExtEntryPoints].name = str_dup(funcName);
 711          ExtEntryTable[NumExtEntryPoints].parameter_signature = NULL;
 712          ExtEntryTable[NumExtEntryPoints].dispatch_offset = ~0;
 713          ExtEntryTable[NumExtEntryPoints].dispatch_stub = entrypoint;
 714          NumExtEntryPoints++;
 715       }
 716    }
 717
 718    return entry;
 719 }
 720
 721
 722 /**
 723  * Fill-in the dispatch stub for the named function.
 724  *
 725  * This function is intended to be called by a hardware driver.  When called,
 726  * a dispatch stub may be created created for the function.  A pointer to this
 727  * dispatch function will be returned by glXGetProcAddress.
 728  *
 729  * \param function_names       Array of pointers to function names that should
 730  *                             share a common dispatch offset.
 731  * \param parameter_signature  String representing the types of the parameters
 732  *                             passed to the named function.  Parameter types
 733  *                             are converted to characters using the following
 734  *                             rules:
 735  *                               - 'i' for \c GLint, \c GLuint, and \c GLenum
 736  *                               - 'p' for any pointer type
 737  *                               - 'f' for \c GLfloat and \c GLclampf
 738  *                               - 'd' for \c GLdouble and \c GLclampd
 739  *
 740  * \returns
 741  * The offset in the dispatch table of the named function.  A pointer to the
 742  * driver's implementation of the named function should be stored at
 743  * \c dispatch_table[\c offset].  Return -1 if error/problem.
 744  *
 745  * \sa glXGetProcAddress
 746  *
 747  * \warning
 748  * This function can only handle up to 8 names at a time.  As far as I know,
 749  * the maximum number of names ever associated with an existing GL function is
 750  * 4 (\c glPointParameterfSGIS, \c glPointParameterfEXT,
 751  * \c glPointParameterfARB, and \c glPointParameterf), so this should not be
 752  * too painful of a limitation.
 753  *
 754  * \todo
 755  * Determine whether or not \c parameter_signature should be allowed to be
 756  * \c NULL.  It doesn't seem like much of a hardship for drivers to have to
 757  * pass in an empty string.
 758  *
 759  * \todo
 760  * Determine if code should be added to reject function names that start with
 761  * 'glX'.
 762  *
 763  * \bug
 764  * Add code to compare \c parameter_signature with the parameter signature of
 765  * a static function.  In order to do that, we need to find a way to \b get
 766  * the parameter signature of a static function.
 767  */
 768
 769 PUBLIC int
 770 _glapi_add_dispatch( const char * const * function_names,
 771                      const char * parameter_signature )
 772 {
 773    static int next_dynamic_offset = _gloffset_FIRST_DYNAMIC;
 774    const char * const real_sig = (parameter_signature != NULL)
 775      ? parameter_signature : "";
 776    struct _glapi_function * entry[8];
 777    GLboolean is_static[8];
 778    unsigned i;
 779    unsigned j;
 780    int offset = ~0;
 781    int new_offset;
 782
 783
 784    (void) memset( is_static, 0, sizeof( is_static ) );
 785    (void) memset( entry, 0, sizeof( entry ) );
 786
 787    for ( i = 0 ; function_names[i] != NULL ; i++ ) {
 788       /* Do some trivial validation on the name of the function.
 789        */
 790
 791       if (!function_names[i] || function_names[i][0] != 'g' || function_names[i][1] != 'l')
 792          return -1;
 793
 794       /* Determine if the named function already exists.  If the function does
 795        * exist, it must have the same parameter signature as the function
 796        * being added.
 797        */
 798
 799       new_offset = get_static_proc_offset(function_names[i]);
 800       if (new_offset >= 0) {
 801          /* FIXME: Make sure the parameter signatures match!  How do we get
 802           * FIXME: the parameter signature for static functions?
 803           */
 804
 805          if ( (offset != ~0) && (new_offset != offset) ) {
 806             return -1;
 807          }
 808
 809          is_static[i] = GL_TRUE;
 810          offset = new_offset;
 811       }
 812
 813
 814       for ( j = 0 ; j < NumExtEntryPoints ; j++ ) {
 815          if (strcmp(ExtEntryTable[j].name, function_names[i]) == 0) {
 816             /* The offset may be ~0 if the function name was added by
 817              * glXGetProcAddress but never filled in by the driver.
 818              */
 819
 820             if (ExtEntryTable[j].dispatch_offset != ~0) {
 821                if (strcmp(real_sig, ExtEntryTable[j].parameter_signature)
 822                    != 0) {
 823                   return -1;
 824                }
 825
 826                if ( (offset != ~0) && (ExtEntryTable[j].dispatch_offset != offset) ) {
 827                   return -1;
 828                }
 829
 830                offset = ExtEntryTable[j].dispatch_offset;
 831             }
 832
 833             entry[i] = & ExtEntryTable[j];
 834             break;
 835          }
 836       }
 837    }
 838
 839    if (offset == ~0) {
 840       offset = next_dynamic_offset;
 841       next_dynamic_offset++;
 842    }
 843
 844    for ( i = 0 ; function_names[i] != NULL ; i++ ) {
 845       if (! is_static[i] ) {
 846          if (entry[i] == NULL) {
 847             entry[i] = add_function_name( function_names[i] );
 848             if (entry[i] == NULL) {
 849                /* FIXME: Possible memory leak here.
 850                 */
 851                return -1;
 852             }
 853          }
 854
 855          entry[i]->parameter_signature = str_dup(real_sig);
 856          fill_in_entrypoint_offset(entry[i]->dispatch_stub, offset);
 857          entry[i]->dispatch_offset = offset;
 858       }
 859    }
 860
 861    return offset;
 862 }
 863
 864
 865 /**
 866  * Return offset of entrypoint for named function within dispatch table.
 867  */
 868 PUBLIC GLint
 869 _glapi_get_proc_offset(const char *funcName)
 870 {
 871    /* search extension functions first */
 872    GLuint i;
 873    for (i = 0; i < NumExtEntryPoints; i++) {
 874       if (strcmp(ExtEntryTable[i].name, funcName) == 0) {
 875          return ExtEntryTable[i].dispatch_offset;
 876       }
 877    }
 878    /* search static functions */
 879    return get_static_proc_offset(funcName);
 880 }
 881
 882
 883
 884 /**
 885  * Return pointer to the named function.  If the function name isn't found
 886  * in the name of static functions, try generating a new API entrypoint on
 887  * the fly with assembly language.
 888  */
 889 _glapi_proc
 890 _glapi_get_proc_address(const char *funcName)
 891 {
 892    struct _glapi_function * entry;
 893    GLuint i;
 894
 895 #ifdef MANGLE
 896    if (funcName[0] != 'm' || funcName[1] != 'g' || funcName[2] != 'l')
 897       return NULL;
 898 #else
 899    if (funcName[0] != 'g' || funcName[1] != 'l')
 900       return NULL;
 901 #endif
 902
 903    /* search extension functions first */
 904    for (i = 0; i < NumExtEntryPoints; i++) {
 905       if (strcmp(ExtEntryTable[i].name, funcName) == 0) {
 906          return ExtEntryTable[i].dispatch_stub;
 907       }
 908    }
 909
 910 #if !defined( XFree86Server ) && !defined( XGLServer )
 911    /* search static functions */
 912    {
 913       const _glapi_proc func = get_static_proc_address(funcName);
 914       if (func)
 915          return func;
 916    }
 917 #endif /* !defined( XFree86Server ) */
 918
 919    entry = add_function_name(funcName);
 920    return (entry == NULL) ? NULL : entry->dispatch_stub;
 921 }
 922
 923
 924
 925 /**
 926  * Return the name of the function at the given dispatch offset.
 927  * This is only intended for debugging.
 928  */
 929 const char *
 930 _glapi_get_proc_name(GLuint offset)
 931 {
 932    GLuint i;
 933    const char * n;
 934
 935    /* search built-in functions */
 936    n = get_static_proc_name(offset);
 937    if ( n != NULL ) {
 938       return n;
 939    }
 940
 941    /* search added extension functions */
 942    for (i = 0; i < NumExtEntryPoints; i++) {
 943       if (ExtEntryTable[i].dispatch_offset == offset) {
 944          return ExtEntryTable[i].name;
 945       }
 946    }
 947    return NULL;
 948 }
 949
 950
 951
 952 /**
 953  * Return size of dispatch table struct as number of functions (or
 954  * slots).
 955  */
 956 PUBLIC GLuint
 957 _glapi_get_dispatch_table_size(void)
 958 {
 959    return DISPATCH_TABLE_SIZE;
 960 }
 961
 962
 963
 964 /**
 965  * Make sure there are no NULL pointers in the given dispatch table.
 966  * Intended for debugging purposes.
 967  */
 968 void
 969 _glapi_check_table(const struct _glapi_table *table)
 970 {
 971 #ifdef DEBUG
 972    const GLuint entries = _glapi_get_dispatch_table_size();
 973    const void **tab = (const void **) table;
 974    GLuint i;
 975    for (i = 1; i < entries; i++) {
 976       assert(tab[i]);
 977    }
 978
 979    /* Do some spot checks to be sure that the dispatch table
 980     * slots are assigned correctly.
 981     */
 982    {
 983       GLuint BeginOffset = _glapi_get_proc_offset("glBegin");
 984       char *BeginFunc = (char*) &table->Begin;
 985       GLuint offset = (BeginFunc - (char *) table) / sizeof(void *);
 986       assert(BeginOffset == _gloffset_Begin);
 987       assert(BeginOffset == offset);
 988    }
 989    {
 990       GLuint viewportOffset = _glapi_get_proc_offset("glViewport");
 991       char *viewportFunc = (char*) &table->Viewport;
 992       GLuint offset = (viewportFunc - (char *) table) / sizeof(void *);
 993       assert(viewportOffset == _gloffset_Viewport);
 994       assert(viewportOffset == offset);
 995    }
 996    {
 997       GLuint VertexPointerOffset = _glapi_get_proc_offset("glVertexPointer");
 998       char *VertexPointerFunc = (char*) &table->VertexPointer;
 999       GLuint offset = (VertexPointerFunc - (char *) table) / sizeof(void *);
1000       assert(VertexPointerOffset == _gloffset_VertexPointer);
1001       assert(VertexPointerOffset == offset);
1002    }
1003    {
1004       GLuint ResetMinMaxOffset = _glapi_get_proc_offset("glResetMinmax");
1005       char *ResetMinMaxFunc = (char*) &table->ResetMinmax;
1006       GLuint offset = (ResetMinMaxFunc - (char *) table) / sizeof(void *);
1007       assert(ResetMinMaxOffset == _gloffset_ResetMinmax);
1008       assert(ResetMinMaxOffset == offset);
1009    }
1010    {
1011       GLuint blendColorOffset = _glapi_get_proc_offset("glBlendColor");
1012       char *blendColorFunc = (char*) &table->BlendColor;
1013       GLuint offset = (blendColorFunc - (char *) table) / sizeof(void *);
1014       assert(blendColorOffset == _gloffset_BlendColor);
1015       assert(blendColorOffset == offset);
1016    }
1017    {
1018       GLuint secondaryColor3fOffset = _glapi_get_proc_offset("glSecondaryColor3fEXT");
1019       char *secondaryColor3fFunc = (char*) &table->SecondaryColor3fEXT;
1020       GLuint offset = (secondaryColor3fFunc - (char *) table) / sizeof(void *);
1021       assert(secondaryColor3fOffset == _gloffset_SecondaryColor3fEXT);
1022       assert(secondaryColor3fOffset == offset);
1023    }
1024    {
1025       GLuint pointParameterivOffset = _glapi_get_proc_offset("glPointParameterivNV");
1026       char *pointParameterivFunc = (char*) &table->PointParameterivNV;
1027       GLuint offset = (pointParameterivFunc - (char *) table) / sizeof(void *);
1028       assert(pointParameterivOffset == _gloffset_PointParameterivNV);
1029       assert(pointParameterivOffset == offset);
1030    }
1031    {
1032       GLuint setFenceOffset = _glapi_get_proc_offset("glSetFenceNV");
1033       char *setFenceFunc = (char*) &table->SetFenceNV;
1034       GLuint offset = (setFenceFunc - (char *) table) / sizeof(void *);
1035       assert(setFenceOffset == _gloffset_SetFenceNV);
1036       assert(setFenceOffset == offset);
1037    }
1038 #else
1039    (void) table;
1040 #endif
1041 }
1042
1043
1044 #if defined(PTHREADS) || defined(GLX_USE_TLS)
1045 /**
1046  * Perform platform-specific GL API entry-point fixups.
1047  */
1048 static void
1049 init_glapi_relocs( void )
1050 {
1051 #if defined(USE_X86_ASM) && defined(GLX_USE_TLS) && !defined(GLX_X86_READONLY_TEXT)
1052     extern unsigned long _x86_get_dispatch(void);
1053     char run_time_patch[] = {
1054        0x65, 0xa1, 0, 0, 0, 0 /* movl %gs:0,%eax */
1055     };
1056     GLuint *offset = (GLuint *) &run_time_patch[2]; /* 32-bits for x86/32 */
1057     const GLubyte * const get_disp = (const GLubyte *) run_time_patch;
1058     GLubyte * curr_func = (GLubyte *) gl_dispatch_functions_start;
1059
1060     *offset = _x86_get_dispatch();
1061     while ( curr_func != (GLubyte *) gl_dispatch_functions_end ) {
1062         (void) memcpy( curr_func, get_disp, sizeof(run_time_patch));
1063         curr_func += DISPATCH_FUNCTION_SIZE;
1064     }
1065 #endif
1066 }
1067 #endif /* defined(PTHREADS) || defined(GLX_USE_TLS) */