src/mapi/glapi/glapi_nop.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   5  * Copyright (C) 2010  VMware, Inc.  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  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /**
  28  * No-op dispatch table.
  29  *
  30  * This file defines a special dispatch table which is loaded with no-op
  31  * functions.
  32  *
  33  * Mesa can register a "no-op handler function" which will be called in
  34  * the event that a no-op function is called.
  35  *
  36  * In the past, the dispatch table was loaded with pointers to a single
  37  * no-op function.  But that broke on Windows because the GL entrypoints
  38  * use __stdcall convention.  __stdcall means the callee cleans up the
  39  * stack.  So one no-op function can't properly clean up the stack.  This
  40  * would lead to crashes.
  41  *
  42  * Another benefit of unique no-op functions is we can accurately report
  43  * the function's name in an error message.
  44  */
  45
  46
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include "glapi/glapi_priv.h"
  50
  51
  52 void
  53 _glapi_noop_enable_warnings(unsigned char enable)
  54 {
  55 }
  56
  57 void
  58 _glapi_set_warning_func(_glapi_proc func)
  59 {
  60 }
  61
  62
  63 /**
  64  * We'll jump though this function pointer whenever a no-op function
  65  * is called.
  66  */
  67 static _glapi_nop_handler_proc nop_handler = NULL;
  68
  69
  70 /**
  71  * Register the no-op handler call-back function.
  72  */
  73 void
  74 _glapi_set_nop_handler(_glapi_nop_handler_proc func)
  75 {
  76    nop_handler = func;
  77 }
  78
  79
  80 /**
  81  * Called by each of the no-op GL entrypoints.
  82  */
  83 static void
  84 nop(const char *func)
  85 {
  86    if (nop_handler)
  87       nop_handler(func);
  88 }
  89
  90
  91 /**
  92  * This is called if the user somehow calls an unassigned GL dispatch function.
  93  */
  94 static GLint
  95 NoOpUnused(void)
  96 {
  97    nop("unused GL entry point");
  98    return 0;
  99 }
 100
 101 /*
 102  * Defines for the glapitemp.h functions.
 103  */
 104 #define KEYWORD1 static
 105 #define KEYWORD1_ALT static
 106 #define KEYWORD2 GLAPIENTRY
 107 #define NAME(func)  NoOp##func
 108 #define DISPATCH(func, args, msg)  nop(#func);
 109 #define RETURN_DISPATCH(func, args, msg)  nop(#func); return 0
 110
 111
 112 /*
 113  * Defines for the table of no-op entry points.
 114  */
 115 #define TABLE_ENTRY(name) (_glapi_proc) NoOp##name
 116 #define DISPATCH_TABLE_NAME __glapi_noop_table
 117 #define UNUSED_TABLE_NAME __unused_noop_functions
 118
 119 #include "glapitemp.h"
 120
 121
 122 /** Return pointer to new dispatch table filled with no-op functions */
 123 struct _glapi_table *
 124 _glapi_new_nop_table(unsigned num_entries)
 125 {
 126    struct _glapi_table *table = malloc(num_entries * sizeof(_glapi_proc));
 127    if (table) {
 128       memcpy(table, __glapi_noop_table,
 129              num_entries * sizeof(_glapi_proc));
 130    }
 131    return table;
 132 }