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