/*
* Mesa 3-D graphics library
*
* Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
/**
* \file glapi_getproc.c
*
* Code for implementing glXGetProcAddress(), etc.
* This was originally in glapi.c but refactored out.
*/
#include <assert.h>
#include <string.h>
#include <stdlib.h>
#include "glapi/glapi_priv.h"
#include "glapitable.h"
#define FIRST_DYNAMIC_OFFSET (sizeof(struct _glapi_table) / sizeof(void *))
/**********************************************************************
* Static function management.
*/
#if !defined(DISPATCH_FUNCTION_SIZE)
# define NEED_FUNCTION_POINTER
#endif
#include "glprocs.h"
/**
* Search the table of static entrypoint functions for the named function
* and return the corresponding glprocs_table_t entry.
*/
static const glprocs_table_t *
get_static_proc( const char * n )
{
GLuint i;
for (i = 0; static_functions[i].Name_offset >= 0; i++) {
const char *testName = gl_string_table + static_functions[i].Name_offset;
if (strcmp(testName, n) == 0)
{
return &static_functions[i];
}
}
return NULL;
}
/**
* Return dispatch table offset of the named static (built-in) function.
* Return -1 if function not found.
*/
static GLint
get_static_proc_offset(const char *funcName)
{
const glprocs_table_t * const f = get_static_proc( funcName );
if (f == NULL) {
return -1;
}
return f->Offset;
}
/**
* Return dispatch function address for the named static (built-in) function.
* Return NULL if function not found.
*/
static _glapi_proc
get_static_proc_address(const char *funcName)
{
const glprocs_table_t * const f = get_static_proc( funcName );
if (f == NULL) {
return NULL;
}
#if defined(DISPATCH_FUNCTION_SIZE) && defined(GLX_INDIRECT_RENDERING)
return (f->Address == NULL)
? get_entrypoint_address(f->Offset)
: f->Address;
#elif defined(DISPATCH_FUNCTION_SIZE)
return get_entrypoint_address(f->Offset);
#else
return f->Address;
#endif
}
/**
* Return the name of the function at the given offset in the dispatch
* table. For debugging only.
*/
static const char *
get_static_proc_name( GLuint offset )
{
GLuint i;
for (i = 0; static_functions[i].Name_offset >= 0; i++) {
if (static_functions[i].Offset == offset) {
return gl_string_table + static_functions[i].Name_offset;
}
}
return NULL;
}
/**********************************************************************
* Extension function management.
*/
/**
* Track information about a function added to the GL API.
*/
struct _glapi_function {
/**
* Name of the function.
*/
const char * name;
/**
* Text string that describes the types of the parameters passed to the
* named function. Parameter types are converted to characters using the
* following rules:
* - 'i' for \c GLint, \c GLuint, and \c GLenum
* - 'p' for any pointer type
* - 'f' for \c GLfloat and \c GLclampf
* - 'd' for \c GLdouble and \c GLclampd
*/
const char * parameter_signature;
/**
* Offset in the dispatch table where the pointer to the real function is
* located. If the driver has not requested that the named function be
* added to the dispatch table, this will have the value ~0.
*/
unsigned dispatch_offset;
/**
* Pointer to the dispatch stub for the named function.
*
* \todo
* The semantic of this field should be changed slightly. Currently, it
* is always expected to be non-\c NULL. However, it would be better to
* only allocate the entry-point stub when the application requests the
* function via \c glXGetProcAddress. This would save memory for all the
* functions that the driver exports but that the application never wants
* to call.
*/
_glapi_proc dispatch_stub;
};
static struct _glapi_function ExtEntryTable[MAX_EXTENSION_FUNCS];
static GLuint NumExtEntryPoints = 0;
static struct _glapi_function *
get_extension_proc(const char *funcName)
{
GLuint i;
for (i = 0; i < NumExtEntryPoints; i++) {
if (strcmp(ExtEntryTable[i].name, funcName) == 0) {
return & ExtEntryTable[i];
}
}
return NULL;
}
static GLint
get_extension_proc_offset(const char *funcName)
{
const struct _glapi_function * const f = get_extension_proc( funcName );
if (f == NULL) {
return -1;
}
return f->dispatch_offset;
}
static _glapi_proc
get_extension_proc_address(const char *funcName)
{
const struct _glapi_function * const f = get_extension_proc( funcName );
if (f == NULL) {
return NULL;
}
return f->dispatch_stub;
}
static const char *
get_extension_proc_name(GLuint offset)
{
GLuint i;
for (i = 0; i < NumExtEntryPoints; i++) {
if (ExtEntryTable[i].dispatch_offset == offset) {
return ExtEntryTable[i].name;
}
}
return NULL;
}
/**
* strdup() is actually not a standard ANSI C or POSIX routine.
* Irix will not define it if ANSI mode is in effect.
*/
static char *
str_dup(const char *str)
{
char *copy;
copy = malloc(strlen(str) + 1);
if (!copy)
return NULL;
strcpy(copy, str);
return copy;
}
/**
* Generate new entrypoint
*
* Use a temporary dispatch offset of ~0 (i.e. -1). Later, when the driver
* calls \c _glapi_add_dispatch we'll put in the proper offset. If that
* never happens, and the user calls this function, he'll segfault. That's
* what you get when you try calling a GL function that doesn't really exist.
*
* \param funcName Name of the function to create an entry-point for.
*
* \sa _glapi_add_entrypoint
*/
static struct _glapi_function *
add_function_name( const char * funcName )
{
struct _glapi_function * entry = NULL;
_glapi_proc entrypoint = NULL;
char * name_dup = NULL;
if (NumExtEntryPoints >= MAX_EXTENSION_FUNCS)
return NULL;
if (funcName == NULL)
return NULL;
name_dup = str_dup(funcName);
if (name_dup == NULL)
return NULL;
entrypoint = generate_entrypoint(~0);
if (entrypoint == NULL) {
free(name_dup);
return NULL;
}
entry = & ExtEntryTable[NumExtEntryPoints];
NumExtEntryPoints++;
entry->name = name_dup;
entry->parameter_signature = NULL;
entry->dispatch_offset = ~0;
entry->dispatch_stub = entrypoint;
return entry;
}
static struct _glapi_function *
set_entry_info( struct _glapi_function * entry, const char * signature, unsigned offset )
{
char * sig_dup = NULL;
if (signature == NULL)
return NULL;
sig_dup = str_dup(signature);
if (sig_dup == NULL)
return NULL;
fill_in_entrypoint_offset(entry->dispatch_stub, offset);
entry->parameter_signature = sig_dup;
entry->dispatch_offset = offset;
return entry;
}
/**
* Fill-in the dispatch stub for the named function.
*
* This function is intended to be called by a hardware driver. When called,
* a dispatch stub may be created for the function. A pointer to this
* dispatch function will be returned by glXGetProcAddress.
*
* \param function_names Array of pointers to function names that should
* share a common dispatch offset.
* \param parameter_signature String representing the types of the parameters
* passed to the named function. Parameter types
* are converted to characters using the following
* rules:
* - 'i' for \c GLint, \c GLuint, and \c GLenum
* - 'p' for any pointer type
* - 'f' for \c GLfloat and \c GLclampf
* - 'd' for \c GLdouble and \c GLclampd
*
* \returns
* The offset in the dispatch table of the named function. A pointer to the
* driver's implementation of the named function should be stored at
* \c dispatch_table[\c offset]. Return -1 if error/problem.
*
* \sa glXGetProcAddress
*
* \warning
* This function can only handle up to 8 names at a time. As far as I know,
* the maximum number of names ever associated with an existing GL function is
* 4 (\c glPointParameterfSGIS, \c glPointParameterfEXT,
* \c glPointParameterfARB, and \c glPointParameterf), so this should not be
* too painful of a limitation.
*
* \todo
* Determine whether or not \c parameter_signature should be allowed to be
* \c NULL. It doesn't seem like much of a hardship for drivers to have to
* pass in an empty string.
*
* \todo
* Determine if code should be added to reject function names that start with
* 'glX'.
*
* \bug
* Add code to compare \c parameter_signature with the parameter signature of
* a static function. In order to do that, we need to find a way to \b get
* the parameter signature of a static function.
*/
int
_glapi_add_dispatch( const char * const * function_names,
const char * parameter_signature )
{
static int next_dynamic_offset = FIRST_DYNAMIC_OFFSET;
const char * const real_sig = (parameter_signature != NULL)
? parameter_signature : "";
struct _glapi_function * entry[8];
GLboolean is_static[8];
unsigned i;
int offset = ~0;
init_glapi_relocs_once();
(void) memset( is_static, 0, sizeof( is_static ) );
(void) memset( entry, 0, sizeof( entry ) );
/* Find the _single_ dispatch offset for all function names that already
* exist (and have a dispatch offset).
*/
for ( i = 0 ; function_names[i] != NULL ; i++ ) {
const char * funcName = function_names[i];
int static_offset;
int extension_offset;
if (funcName[0] != 'g' || funcName[1] != 'l')
return -1;
/* search built-in functions */
static_offset = get_static_proc_offset(funcName);
if (static_offset >= 0) {
is_static[i] = GL_TRUE;
/* FIXME: Make sure the parameter signatures match! How do we get
* FIXME: the parameter signature for static functions?
*/
if ( (offset != ~0) && (static_offset != offset) ) {
return -1;
}
offset = static_offset;
continue;
}
/* search added extension functions */
entry[i] = get_extension_proc(funcName);
if (entry[i] != NULL) {
extension_offset = entry[i]->dispatch_offset;
/* The offset may be ~0 if the function name was added by
* glXGetProcAddress but never filled in by the driver.
*/
if (extension_offset == ~0) {
continue;
}
if (strcmp(real_sig, entry[i]->parameter_signature) != 0) {
return -1;
}
if ( (offset != ~0) && (extension_offset != offset) ) {
return -1;
}
offset = extension_offset;
}
}
/* If all function names are either new (or with no dispatch offset),
* allocate a new dispatch offset.
*/
if (offset == ~0) {
offset = next_dynamic_offset;
next_dynamic_offset++;
}
/* Fill in the dispatch offset for the new function names (and those with
* no dispatch offset).
*/
for ( i = 0 ; function_names[i] != NULL ; i++ ) {
if (is_static[i]) {
continue;
}
/* generate entrypoints for new function names */
if (entry[i] == NULL) {
entry[i] = add_function_name( function_names[i] );
if (entry[i] == NULL) {
/* FIXME: Possible memory leak here. */
return -1;
}
}
if (entry[i]->dispatch_offset == ~0) {
set_entry_info( entry[i], real_sig, offset );
}
}
return offset;
}
/**
* Return offset of entrypoint for named function within dispatch table.
*/
GLint
_glapi_get_proc_offset(const char *funcName)
{
GLint offset;
/* search extension functions first */
offset = get_extension_proc_offset(funcName);
if (offset >= 0)
return offset;
/* search static functions */
return get_static_proc_offset(funcName);
}
/**
* Return pointer to the named function. If the function name isn't found
* in the name of static functions, try generating a new API entrypoint on
* the fly with assembly language.
*/
_glapi_proc
_glapi_get_proc_address(const char *funcName)
{
_glapi_proc func;
struct _glapi_function * entry;
init_glapi_relocs_once();
#ifdef USE_MGL_NAMESPACE
if (funcName && funcName[0] == 'm')
funcName++;
#endif
if (!funcName || funcName[0] != 'g' || funcName[1] != 'l')
return NULL;
/* search extension functions first */
func = get_extension_proc_address(funcName);
if (func)
return func;
/* search static functions */
func = get_static_proc_address(funcName);
if (func)
return func;
/* generate entrypoint, dispatch offset must be filled in by the driver */
entry = add_function_name(funcName);
if (entry == NULL)
return NULL;
return entry->dispatch_stub;
}
/**
* Return the name of the function at the given dispatch offset.
* This is only intended for debugging.
*/
const char *
_glapi_get_proc_name(GLuint offset)
{
const char * n;
/* search built-in functions */
n = get_static_proc_name(offset);
if ( n != NULL ) {
return n;
}
/* search added extension functions */
return get_extension_proc_name(offset);
}
/**********************************************************************
* GL API table functions.
*/
/**
* Return size of dispatch table struct as number of functions (or
* slots).
*/
GLuint
_glapi_get_dispatch_table_size(void)
{
/*
* The dispatch table size (number of entries) is the size of the
* _glapi_table struct plus the number of dynamic entries we can add.
* The extra slots can be filled in by DRI drivers that register new
* extension functions.
*/
return FIRST_DYNAMIC_OFFSET + MAX_EXTENSION_FUNCS;
}