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