/* * Mesa 3-D graphics library * Version: 7.1 * * 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 * BRIAN PAUL 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 "glapi/glapi_priv.h" #include "glapi/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 "glapi/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; #ifdef MANGLE /* skip the prefix on the name */ if (strcmp(testName, n + 1) == 0) #else if (strcmp(testName, n) == 0) #endif { 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 = (char*) 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 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 MANGLE /* skip the prefix on the name */ if (funcName[1] != 'g' || funcName[2] != 'l') return NULL; #else if (funcName[0] != 'g' || funcName[1] != 'l') return NULL; #endif /* 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; } /** * Make sure there are no NULL pointers in the given dispatch table. * Intended for debugging purposes. */ void _glapi_check_table_not_null(const struct _glapi_table *table) { #ifdef EXTRA_DEBUG /* set to DEBUG for extra DEBUG */ const GLuint entries = _glapi_get_dispatch_table_size(); const void **tab = (const void **) table; GLuint i; for (i = 1; i < entries; i++) { assert(tab[i]); } #else (void) table; #endif } /** * Do some spot checks to be sure that the dispatch table * slots are assigned correctly. For debugging only. */ void _glapi_check_table(const struct _glapi_table *table) { #ifdef EXTRA_DEBUG /* set to DEBUG for extra DEBUG */ { GLuint BeginOffset = _glapi_get_proc_offset("glBegin"); char *BeginFunc = (char*) &table->Begin; GLuint offset = (BeginFunc - (char *) table) / sizeof(void *); assert(BeginOffset == offset); } { GLuint viewportOffset = _glapi_get_proc_offset("glViewport"); char *viewportFunc = (char*) &table->Viewport; GLuint offset = (viewportFunc - (char *) table) / sizeof(void *); assert(viewportOffset == offset); } { GLuint VertexPointerOffset = _glapi_get_proc_offset("glVertexPointer"); char *VertexPointerFunc = (char*) &table->VertexPointer; GLuint offset = (VertexPointerFunc - (char *) table) / sizeof(void *); assert(VertexPointerOffset == offset); } { GLuint ResetMinMaxOffset = _glapi_get_proc_offset("glResetMinmax"); char *ResetMinMaxFunc = (char*) &table->ResetMinmax; GLuint offset = (ResetMinMaxFunc - (char *) table) / sizeof(void *); assert(ResetMinMaxOffset == offset); } { GLuint blendColorOffset = _glapi_get_proc_offset("glBlendColor"); char *blendColorFunc = (char*) &table->BlendColor; GLuint offset = (blendColorFunc - (char *) table) / sizeof(void *); assert(blendColorOffset == offset); } { GLuint secondaryColor3fOffset = _glapi_get_proc_offset("glSecondaryColor3fEXT"); char *secondaryColor3fFunc = (char*) &table->SecondaryColor3fEXT; GLuint offset = (secondaryColor3fFunc - (char *) table) / sizeof(void *); assert(secondaryColor3fOffset == offset); } { GLuint pointParameterivOffset = _glapi_get_proc_offset("glPointParameterivNV"); char *pointParameterivFunc = (char*) &table->PointParameterivNV; GLuint offset = (pointParameterivFunc - (char *) table) / sizeof(void *); assert(pointParameterivOffset == offset); } { GLuint setFenceOffset = _glapi_get_proc_offset("glSetFenceNV"); char *setFenceFunc = (char*) &table->SetFenceNV; GLuint offset = (setFenceFunc - (char *) table) / sizeof(void *); assert(setFenceOffset == offset); } #else (void) table; #endif }