2 * Mesa 3-D graphics library
4 * Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
26 * \file glapi_getproc.c
28 * Code for implementing glXGetProcAddress(), etc.
29 * This was originally in glapi.c but refactored out.
36 #include "glapi/glapi_priv.h"
37 #include "glapi/glapitable.h"
40 #define FIRST_DYNAMIC_OFFSET (sizeof(struct _glapi_table) / sizeof(void *))
44 /**********************************************************************
45 * Static function management.
49 #if !defined(DISPATCH_FUNCTION_SIZE)
50 # define NEED_FUNCTION_POINTER
52 #include "glapi/glprocs.h"
56 * Search the table of static entrypoint functions for the named function
57 * and return the corresponding glprocs_table_t entry.
59 static const glprocs_table_t
*
60 get_static_proc( const char * n
)
63 for (i
= 0; static_functions
[i
].Name_offset
>= 0; i
++) {
64 const char *testName
= gl_string_table
+ static_functions
[i
].Name_offset
;
66 /* skip the prefix on the name */
67 if (strcmp(testName
, n
+ 1) == 0)
69 if (strcmp(testName
, n
) == 0)
72 return &static_functions
[i
];
80 * Return dispatch table offset of the named static (built-in) function.
81 * Return -1 if function not found.
84 get_static_proc_offset(const char *funcName
)
86 const glprocs_table_t
* const f
= get_static_proc( funcName
);
97 * Return dispatch function address for the named static (built-in) function.
98 * Return NULL if function not found.
101 get_static_proc_address(const char *funcName
)
103 const glprocs_table_t
* const f
= get_static_proc( funcName
);
108 #if defined(DISPATCH_FUNCTION_SIZE) && defined(GLX_INDIRECT_RENDERING)
109 return (f
->Address
== NULL
)
110 ? get_entrypoint_address(f
->Offset
)
112 #elif defined(DISPATCH_FUNCTION_SIZE)
113 return get_entrypoint_address(f
->Offset
);
122 * Return the name of the function at the given offset in the dispatch
123 * table. For debugging only.
126 get_static_proc_name( GLuint offset
)
129 for (i
= 0; static_functions
[i
].Name_offset
>= 0; i
++) {
130 if (static_functions
[i
].Offset
== offset
) {
131 return gl_string_table
+ static_functions
[i
].Name_offset
;
139 /**********************************************************************
140 * Extension function management.
145 * Track information about a function added to the GL API.
147 struct _glapi_function
{
149 * Name of the function.
155 * Text string that describes the types of the parameters passed to the
156 * named function. Parameter types are converted to characters using the
158 * - 'i' for \c GLint, \c GLuint, and \c GLenum
159 * - 'p' for any pointer type
160 * - 'f' for \c GLfloat and \c GLclampf
161 * - 'd' for \c GLdouble and \c GLclampd
163 const char * parameter_signature
;
167 * Offset in the dispatch table where the pointer to the real function is
168 * located. If the driver has not requested that the named function be
169 * added to the dispatch table, this will have the value ~0.
171 unsigned dispatch_offset
;
175 * Pointer to the dispatch stub for the named function.
178 * The semantic of this field should be changed slightly. Currently, it
179 * is always expected to be non-\c NULL. However, it would be better to
180 * only allocate the entry-point stub when the application requests the
181 * function via \c glXGetProcAddress. This would save memory for all the
182 * functions that the driver exports but that the application never wants
185 _glapi_proc dispatch_stub
;
189 static struct _glapi_function ExtEntryTable
[MAX_EXTENSION_FUNCS
];
190 static GLuint NumExtEntryPoints
= 0;
193 static struct _glapi_function
*
194 get_extension_proc(const char *funcName
)
197 for (i
= 0; i
< NumExtEntryPoints
; i
++) {
198 if (strcmp(ExtEntryTable
[i
].name
, funcName
) == 0) {
199 return & ExtEntryTable
[i
];
207 get_extension_proc_offset(const char *funcName
)
209 const struct _glapi_function
* const f
= get_extension_proc( funcName
);
214 return f
->dispatch_offset
;
219 get_extension_proc_address(const char *funcName
)
221 const struct _glapi_function
* const f
= get_extension_proc( funcName
);
226 return f
->dispatch_stub
;
231 get_extension_proc_name(GLuint offset
)
234 for (i
= 0; i
< NumExtEntryPoints
; i
++) {
235 if (ExtEntryTable
[i
].dispatch_offset
== offset
) {
236 return ExtEntryTable
[i
].name
;
244 * strdup() is actually not a standard ANSI C or POSIX routine.
245 * Irix will not define it if ANSI mode is in effect.
248 str_dup(const char *str
)
251 copy
= malloc(strlen(str
) + 1);
260 * Generate new entrypoint
262 * Use a temporary dispatch offset of ~0 (i.e. -1). Later, when the driver
263 * calls \c _glapi_add_dispatch we'll put in the proper offset. If that
264 * never happens, and the user calls this function, he'll segfault. That's
265 * what you get when you try calling a GL function that doesn't really exist.
267 * \param funcName Name of the function to create an entry-point for.
269 * \sa _glapi_add_entrypoint
272 static struct _glapi_function
*
273 add_function_name( const char * funcName
)
275 struct _glapi_function
* entry
= NULL
;
276 _glapi_proc entrypoint
= NULL
;
277 char * name_dup
= NULL
;
279 if (NumExtEntryPoints
>= MAX_EXTENSION_FUNCS
)
282 if (funcName
== NULL
)
285 name_dup
= str_dup(funcName
);
286 if (name_dup
== NULL
)
289 entrypoint
= generate_entrypoint(~0);
291 if (entrypoint
== NULL
) {
296 entry
= & ExtEntryTable
[NumExtEntryPoints
];
299 entry
->name
= name_dup
;
300 entry
->parameter_signature
= NULL
;
301 entry
->dispatch_offset
= ~0;
302 entry
->dispatch_stub
= entrypoint
;
308 static struct _glapi_function
*
309 set_entry_info( struct _glapi_function
* entry
, const char * signature
, unsigned offset
)
311 char * sig_dup
= NULL
;
313 if (signature
== NULL
)
316 sig_dup
= str_dup(signature
);
320 fill_in_entrypoint_offset(entry
->dispatch_stub
, offset
);
322 entry
->parameter_signature
= sig_dup
;
323 entry
->dispatch_offset
= offset
;
330 * Fill-in the dispatch stub for the named function.
332 * This function is intended to be called by a hardware driver. When called,
333 * a dispatch stub may be created created for the function. A pointer to this
334 * dispatch function will be returned by glXGetProcAddress.
336 * \param function_names Array of pointers to function names that should
337 * share a common dispatch offset.
338 * \param parameter_signature String representing the types of the parameters
339 * passed to the named function. Parameter types
340 * are converted to characters using the following
342 * - 'i' for \c GLint, \c GLuint, and \c GLenum
343 * - 'p' for any pointer type
344 * - 'f' for \c GLfloat and \c GLclampf
345 * - 'd' for \c GLdouble and \c GLclampd
348 * The offset in the dispatch table of the named function. A pointer to the
349 * driver's implementation of the named function should be stored at
350 * \c dispatch_table[\c offset]. Return -1 if error/problem.
352 * \sa glXGetProcAddress
355 * This function can only handle up to 8 names at a time. As far as I know,
356 * the maximum number of names ever associated with an existing GL function is
357 * 4 (\c glPointParameterfSGIS, \c glPointParameterfEXT,
358 * \c glPointParameterfARB, and \c glPointParameterf), so this should not be
359 * too painful of a limitation.
362 * Determine whether or not \c parameter_signature should be allowed to be
363 * \c NULL. It doesn't seem like much of a hardship for drivers to have to
364 * pass in an empty string.
367 * Determine if code should be added to reject function names that start with
371 * Add code to compare \c parameter_signature with the parameter signature of
372 * a static function. In order to do that, we need to find a way to \b get
373 * the parameter signature of a static function.
377 _glapi_add_dispatch( const char * const * function_names
,
378 const char * parameter_signature
)
380 static int next_dynamic_offset
= FIRST_DYNAMIC_OFFSET
;
381 const char * const real_sig
= (parameter_signature
!= NULL
)
382 ? parameter_signature
: "";
383 struct _glapi_function
* entry
[8];
384 GLboolean is_static
[8];
388 init_glapi_relocs_once();
390 (void) memset( is_static
, 0, sizeof( is_static
) );
391 (void) memset( entry
, 0, sizeof( entry
) );
393 /* Find the _single_ dispatch offset for all function names that already
394 * exist (and have a dispatch offset).
397 for ( i
= 0 ; function_names
[i
] != NULL
; i
++ ) {
398 const char * funcName
= function_names
[i
];
400 int extension_offset
;
402 if (funcName
[0] != 'g' || funcName
[1] != 'l')
405 /* search built-in functions */
406 static_offset
= get_static_proc_offset(funcName
);
408 if (static_offset
>= 0) {
410 is_static
[i
] = GL_TRUE
;
412 /* FIXME: Make sure the parameter signatures match! How do we get
413 * FIXME: the parameter signature for static functions?
416 if ( (offset
!= ~0) && (static_offset
!= offset
) ) {
420 offset
= static_offset
;
425 /* search added extension functions */
426 entry
[i
] = get_extension_proc(funcName
);
428 if (entry
[i
] != NULL
) {
429 extension_offset
= entry
[i
]->dispatch_offset
;
431 /* The offset may be ~0 if the function name was added by
432 * glXGetProcAddress but never filled in by the driver.
435 if (extension_offset
== ~0) {
439 if (strcmp(real_sig
, entry
[i
]->parameter_signature
) != 0) {
443 if ( (offset
!= ~0) && (extension_offset
!= offset
) ) {
447 offset
= extension_offset
;
451 /* If all function names are either new (or with no dispatch offset),
452 * allocate a new dispatch offset.
456 offset
= next_dynamic_offset
;
457 next_dynamic_offset
++;
460 /* Fill in the dispatch offset for the new function names (and those with
461 * no dispatch offset).
464 for ( i
= 0 ; function_names
[i
] != NULL
; i
++ ) {
469 /* generate entrypoints for new function names */
470 if (entry
[i
] == NULL
) {
471 entry
[i
] = add_function_name( function_names
[i
] );
472 if (entry
[i
] == NULL
) {
473 /* FIXME: Possible memory leak here. */
478 if (entry
[i
]->dispatch_offset
== ~0) {
479 set_entry_info( entry
[i
], real_sig
, offset
);
488 * Return offset of entrypoint for named function within dispatch table.
491 _glapi_get_proc_offset(const char *funcName
)
495 /* search extension functions first */
496 offset
= get_extension_proc_offset(funcName
);
500 /* search static functions */
501 return get_static_proc_offset(funcName
);
507 * Return pointer to the named function. If the function name isn't found
508 * in the name of static functions, try generating a new API entrypoint on
509 * the fly with assembly language.
512 _glapi_get_proc_address(const char *funcName
)
515 struct _glapi_function
* entry
;
517 init_glapi_relocs_once();
520 /* skip the prefix on the name */
521 if (funcName
[1] != 'g' || funcName
[2] != 'l')
524 if (funcName
[0] != 'g' || funcName
[1] != 'l')
528 /* search extension functions first */
529 func
= get_extension_proc_address(funcName
);
533 /* search static functions */
534 func
= get_static_proc_address(funcName
);
538 /* generate entrypoint, dispatch offset must be filled in by the driver */
539 entry
= add_function_name(funcName
);
543 return entry
->dispatch_stub
;
549 * Return the name of the function at the given dispatch offset.
550 * This is only intended for debugging.
553 _glapi_get_proc_name(GLuint offset
)
557 /* search built-in functions */
558 n
= get_static_proc_name(offset
);
563 /* search added extension functions */
564 return get_extension_proc_name(offset
);
569 /**********************************************************************
570 * GL API table functions.
575 * Return size of dispatch table struct as number of functions (or
579 _glapi_get_dispatch_table_size(void)
582 * The dispatch table size (number of entries) is the size of the
583 * _glapi_table struct plus the number of dynamic entries we can add.
584 * The extra slots can be filled in by DRI drivers that register new
585 * extension functions.
587 return FIRST_DYNAMIC_OFFSET
+ MAX_EXTENSION_FUNCS
;
592 * Make sure there are no NULL pointers in the given dispatch table.
593 * Intended for debugging purposes.
596 _glapi_check_table_not_null(const struct _glapi_table
*table
)
598 #ifdef EXTRA_DEBUG /* set to DEBUG for extra DEBUG */
599 const GLuint entries
= _glapi_get_dispatch_table_size();
600 const void **tab
= (const void **) table
;
602 for (i
= 1; i
< entries
; i
++) {
612 * Do some spot checks to be sure that the dispatch table
613 * slots are assigned correctly. For debugging only.
616 _glapi_check_table(const struct _glapi_table
*table
)
618 #ifdef EXTRA_DEBUG /* set to DEBUG for extra DEBUG */
620 GLuint BeginOffset
= _glapi_get_proc_offset("glBegin");
621 char *BeginFunc
= (char*) &table
->Begin
;
622 GLuint offset
= (BeginFunc
- (char *) table
) / sizeof(void *);
623 assert(BeginOffset
== offset
);
626 GLuint viewportOffset
= _glapi_get_proc_offset("glViewport");
627 char *viewportFunc
= (char*) &table
->Viewport
;
628 GLuint offset
= (viewportFunc
- (char *) table
) / sizeof(void *);
629 assert(viewportOffset
== offset
);
632 GLuint VertexPointerOffset
= _glapi_get_proc_offset("glVertexPointer");
633 char *VertexPointerFunc
= (char*) &table
->VertexPointer
;
634 GLuint offset
= (VertexPointerFunc
- (char *) table
) / sizeof(void *);
635 assert(VertexPointerOffset
== offset
);
638 GLuint ResetMinMaxOffset
= _glapi_get_proc_offset("glResetMinmax");
639 char *ResetMinMaxFunc
= (char*) &table
->ResetMinmax
;
640 GLuint offset
= (ResetMinMaxFunc
- (char *) table
) / sizeof(void *);
641 assert(ResetMinMaxOffset
== offset
);
644 GLuint blendColorOffset
= _glapi_get_proc_offset("glBlendColor");
645 char *blendColorFunc
= (char*) &table
->BlendColor
;
646 GLuint offset
= (blendColorFunc
- (char *) table
) / sizeof(void *);
647 assert(blendColorOffset
== offset
);
650 GLuint secondaryColor3fOffset
= _glapi_get_proc_offset("glSecondaryColor3fEXT");
651 char *secondaryColor3fFunc
= (char*) &table
->SecondaryColor3fEXT
;
652 GLuint offset
= (secondaryColor3fFunc
- (char *) table
) / sizeof(void *);
653 assert(secondaryColor3fOffset
== offset
);
656 GLuint pointParameterivOffset
= _glapi_get_proc_offset("glPointParameterivNV");
657 char *pointParameterivFunc
= (char*) &table
->PointParameterivNV
;
658 GLuint offset
= (pointParameterivFunc
- (char *) table
) / sizeof(void *);
659 assert(pointParameterivOffset
== offset
);
662 GLuint setFenceOffset
= _glapi_get_proc_offset("glSetFenceNV");
663 char *setFenceFunc
= (char*) &table
->SetFenceNV
;
664 GLuint offset
= (setFenceFunc
- (char *) table
) / sizeof(void *);
665 assert(setFenceOffset
== offset
);