Sweden-Number/dlls/opengl32/make_opengl

#!/usr/bin/perl -w
use strict;
use XML::LibXML;

# This script is called thus :
#
#   make_opengl [opengl_version]
#
#     - It needs files from the OpenGL extension registry:
#
#       https://raw.github.com/KhronosGroup/OpenGL-Registry/master/xml/gl.xml
#       https://raw.github.com/KhronosGroup/OpenGL-Registry/master/xml/wgl.xml
#
#       If they are not found in the current directory the script will
#       attempt to download them from there.
#
#     - opengl_version is the OpenGL version emulated by the library
#       (can be 1.0 to 1.5). The default is 1.1.
#
# This script generates the three following files :
#
#     - opengl32.spec : the spec file giving all the exported functions
#       of the OpenGL32.DLL library. These functions are the one an
#       application can directly link to (and are all the functions
#       defined in the OpenGL core for the version defined by
#       'opengl_version').
#
#     - opengl_norm.c : this file contains the thunks for all OpenGL
#       functions that are defined in 'opengl32.spec'. The corresponding
#       functions NEED to be defined in Linux's libGL or the library
#       won't be able to be linked in.
#
#     - opengl_ext.c : in this file are stored thunks for ALL possible
#       OpenGL extensions (at least, all the extensions that are defined
#       in the OpenGL extension registry). Contrary to 'opengl_norm.c',
#       you do not need to have these extensions in your libGL to have
#       OpenGL work (as they are resolved at run-time using
#       glXGetProcAddressARB).
#
#     - include/wine/wgl_driver.h: definitions for the tables of OpenGL functions.
#
#
# Copyright 2000 Lionel Ulmer
# Copyright 2012 Alexandre Julliard
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
#

#
# Files to generate
#
my $spec_file = "opengl32.spec";
my $norm_file = "opengl_norm.c";
my $ext_file  = "opengl_ext.c";
my $wgl_driver_file = "../../include/wine/wgl_driver.h";
my $wgl_file = "../../include/wine/wgl.h";

# If set to 1, generate TRACEs for each OpenGL function
my $gen_traces = 1;

#
# List of categories to put in the 'opengl_norm.c' file
#
my %cat_1_0 = ( "GL_VERSION_1_0" => 1 );
my %cat_1_1 = ( %cat_1_0, "GL_VERSION_1_1" => 1 );
my %cat_1_2 = ( %cat_1_1, "GL_VERSION_1_2" => 1 );
my %cat_1_3 = ( %cat_1_2, "GL_VERSION_1_3" => 1 );
my %cat_1_4 = ( %cat_1_3, "GL_VERSION_1_4" => 1 );
my %cat_1_5 = ( %cat_1_4, "GL_VERSION_1_5" => 1 );

my %norm_categories = ();

#
# This hash table gives the conversion between OpenGL types and
# the .spec type and debug format
#
my %arg_types =
    (
     "GLbitfield" =>           [ "long",   "%d" ],
     "GLboolean" =>            [ "long",   "%d" ],
     "GLbyte" =>               [ "long",   "%d" ],
     "GLchar" =>               [ "long",   "%c" ],
     "GLcharARB" =>            [ "long",   "%c" ],
     "GLclampd" =>             [ "double", "%f" ],
     "GLclampf" =>             [ "float",  "%f" ],
     "GLclampx" =>             [ "long",   "%d" ],
     "GLdouble" =>             [ "double", "%f" ],
     "GLeglClientBufferEXT" => [ "ptr",    "%p" ],
     "GLenum" =>               [ "long",   "%d" ],
     "GLfixed" =>              [ "long",   "%d" ],
     "GLfloat" =>              [ "float",  "%f" ],
     "GLhalfNV" =>             [ "long",   "%d" ],
     "GLhandleARB" =>          [ "long",   "%d" ],
     "GLint" =>                [ "long",   "%d" ],
     "GLint64" =>              [ "int64",  "wine_dbgstr_longlong(%s)" ],
     "GLint64EXT" =>           [ "int64",  "wine_dbgstr_longlong(%s)" ],
     "GLintptr" =>             [ "long",   "%ld" ],
     "GLintptrARB" =>          [ "long",   "%ld" ],
     "GLshort" =>              [ "long",   "%d" ],
     "GLsizei" =>              [ "long",   "%d" ],
     "GLsizeiptr" =>           [ "long",   "%ld" ],
     "GLsizeiptrARB" =>        [ "long",   "%ld" ],
     "GLstring" =>             [ "str",    "wine_dbgstr_a(%s)" ],
     "GLsync" =>               [ "ptr",    "%p" ],
     "GLubyte" =>              [ "long",   "%d" ],
     "GLuint" =>               [ "long",   "%d" ],
     "GLuint64" =>             [ "int64",  "wine_dbgstr_longlong(%s)" ],
     "GLuint64EXT" =>          [ "int64",  "wine_dbgstr_longlong(%s)" ],
     "GLushort" =>             [ "long",   "%d" ],
     "GLvdpauSurfaceNV" =>     [ "long",   "%ld" ],
     "GLDEBUGPROC" =>          [ "ptr",    "%p" ],
     "GLDEBUGPROCARB" =>       [ "ptr",    "%p" ],
     "GLDEBUGPROCAMD" =>       [ "ptr",    "%p" ],
     "GLDEBUGPROCKHR" =>       [ "ptr",    "%p" ],
     "GLVULKANPROCNV" =>       [ "ptr",    "%p" ],
     "HDC" =>                  [ "long",   "%p" ],
     "HGLRC" =>                [ "long",   "%p" ],
     "HPBUFFERARB" =>          [ "long",   "%p" ],
     "HENHMETAFILE" =>         [ "long",   "%p" ],
     "LPGLYPHMETRICSFLOAT" =>  [ "ptr",    "%p" ],
     "LPCSTR" =>               [ "str",    "wine_dbgstr_a(%s)" ],
     "UINT" =>                 [ "long",   "%u" ],
     "DWORD" =>                [ "long",   "%u" ],
     "BOOL" =>                 [ "long",   "%u" ],
     "FLOAT" =>                [ "float",  "%f" ],
    );

my %remap_types =
    (
     "HGLRC" => "struct wgl_context *",
     "HPBUFFERARB" => "struct wgl_pbuffer *",
    );
#
# Used to convert some types
#
sub ConvertType($)
{
    my $arg = shift;
    my $ret = $arg->textContent();
    my @type = $arg->findnodes("./ptype");

    if (@type)
    {
        my $type = $type[0]->textContent();
        $ret =~ s/$type/$remap_types{$type}/ if defined $remap_types{$type};
    }
    return $ret;
}

#
# This functions generates the thunk for a given function.
#
sub GenerateThunk($$$)
{
    my ($name, $func_ref, $prefix) = @_;
    my $call_arg = "";
    my $trace_call_arg = "";
    my $trace_arg = "";

    return "" if $name eq "glDebugEntry";
    return "" if $name eq "glGetIntegerv";
    return "" if $name eq "glGetString";
    return "" if $func_ref->[2] && $func_ref->[2]->[0] =~ /WGL_/;

    my $ret = get_func_proto( "%s WINAPI %s(%s)", $name, $func_ref );
    foreach my $arg (@{$func_ref->[1]}) {
        my $ptype = get_arg_type( $arg );
        my $pname = get_arg_name( $arg );
        my $param = $arg->textContent();
        $call_arg .= " " . $pname . ",";
        if ($param =~ /\*/ || $param =~ /\[/) {
            $trace_arg .= ", %p";
            $trace_call_arg .= ", " . $pname;
        } elsif (defined $arg_types{$ptype}) {
            my $format = ${$arg_types{$ptype}}[1];
            $trace_arg .= ", " . ($format =~ /^%/ ? $format : "%s");
            $trace_call_arg .= ", " . sprintf $format =~ /^%/ ? "%s" : $format, $pname;
        }
        else { printf "Unknown type %s in %s\n", $param, $name; }
    }
    $call_arg =~ s/,$/ /;
    $trace_arg =~ s/^, //;
    return "$ret DECLSPEC_HIDDEN;\n" if $name eq "glGetStringi";
    $ret .= "\n{\n  const struct opengl_funcs *funcs = NtCurrentTeb()->glTable;\n";
    $ret .= "  TRACE( \"($trace_arg)\\n\"$trace_call_arg );\n" if $gen_traces;
    $ret .= "  ";
    $ret .= "return " unless is_void_func( $func_ref );
    $ret .= "funcs->$prefix.p_$name($call_arg);\n";
    $ret .= "}\n";
    return $ret;
}

sub generate_null_func($$)
{
    my ($name, $func_ref) = @_;
    my $ret;

    return "" if $name eq "glDebugEntry";

    $ret = get_func_proto( "static %s null_%s(%s)", $name, $func_ref );
    $ret .= " {";
    if ($name eq "glGetError")
    {
        $ret .= " return GL_INVALID_OPERATION;";
    }
    elsif (!is_void_func( $func_ref ))
    {
        $ret .= " return 0;";
    }
    $ret .= " }\n";
    return $ret;
}

sub generate_spec_entry($$)
{
    my ($name, $func) = @_;
    my $args=" ";
    foreach my $arg (@{$func->[1]})
    {
        my $ptype = get_arg_type( $arg );
        my $param = $arg->textContent();
        if ($param =~ /[[*]/) {
            $args .= "ptr ";
        } elsif (defined($arg_types{$ptype})) {
            $args .= "$@$arg_types{$ptype}[0] ";
        } else {
            die "No conversion for func $name type $param\n";
        }
    }
    $args = substr($args,1,-1);
    return "@ stdcall $_($args)";
}

sub is_void_func($)
{
    my $func = shift;
    return 0 if @{$func->[0]->findnodes("./ptype")};
    return $func->[0]->textContent() eq "void ";
}

sub get_arg_type($)
{
    my $p = shift;
    my @type = $p->findnodes("./ptype");
    return @type ? $type[0]->textContent() : "GLint";
}

sub get_arg_name($)
{
    my $p = shift;
    my @name = $p->findnodes("./name");
    return $name[0]->textContent();
}

sub get_func_proto($$$)
{
    my ($format, $name, $func) = @_;
    die "unknown func $name" unless defined $func->[0];
    my $proto = ConvertType( $func->[0] );
    $proto =~ s/ $//;
    my $args = "";
    foreach my $arg (@{$func->[1]})
    {
        $args .= " " . ConvertType( $arg ) . ",";
    }
    $args =~ s/,$/ /;
    $args ||= "void";
    return sprintf $format, $proto, $name, $args;
}

#
# Extract and checks the number of arguments
#
if (@ARGV > 1) {
    my $name0=$0;
    $name0=~s%^.*/%%;
    die "Usage: $name0 [version]\n";
}
my $version = $ARGV[0] || "1.1";
if ($version eq "1.0") {
    %norm_categories = %cat_1_0;
} elsif ($version eq "1.1") {
    %norm_categories = %cat_1_1;
} elsif ($version eq "1.2") {
    %norm_categories = %cat_1_2;
} elsif ($version eq "1.3") {
    %norm_categories = %cat_1_3;
} elsif ($version eq "1.4") {
    %norm_categories = %cat_1_4;
} elsif ($version eq "1.5") {
    %norm_categories = %cat_1_5;
} else {
    die "Incorrect OpenGL version.\n";
}

#
# Fetch the registry files
#
-f "gl.xml" || system "wget https://raw.github.com/KhronosGroup/OpenGL-Registry/master/xml/gl.xml" || die "cannot download gl.xml";
-f "wgl.xml" || system "wget https://raw.github.com/KhronosGroup/OpenGL-Registry/master/xml/wgl.xml" || die "cannot download wgl.xml";


#
# Then, create the list of all OpenGL functions using the registry
# files. This will create two hash-tables, one with all the function
# whose category matches the one listed in '@norm_categories', the other
# with all other functions.
#
# An element of the hash table is a reference to an array with these
# elements :
#
#  - XML node of the function prototype
#
#  - reference to an array of XML nodes giving the list of arguments (an empty array
#    for a 'void' function).
#
my %norm_functions;
my %ext_functions;
my %wgl_functions;
my (%gl_types, @gl_types);  # also use an array to preserve declaration order

my %supported_wgl_functions =
    (
     "wglCopyContext" => 1,
     "wglCreateContext" => 1,
     "wglDeleteContext" => 1,
     "wglDescribePixelFormat" => 1,
     "wglGetPixelFormat" => 1,
     "wglGetProcAddress" => 1,
     "wglMakeCurrent" => 1,
     "wglSetPixelFormat" => 1,
     "wglShareLists" => 1,
     "wglSwapBuffers" => 1,
    );

my %remapped_wgl_functions =
    (
     "ChoosePixelFormat" => "wglChoosePixelFormat",
     "DescribePixelFormat" => "wglDescribePixelFormat",
     "GetPixelFormat" => "wglGetPixelFormat",
     "GetEnhMetaFilePixelFormat" => 0,
     "SetPixelFormat" => "wglSetPixelFormat",
     "SwapBuffers" => "wglSwapBuffers",
     "wglUseFontBitmaps" => 0,
     "wglUseFontOutlines" => 0,
    );

my %supported_wgl_extensions =
   (
    "WGL_ARB_create_context" => 1,
    "WGL_ARB_extensions_string" => 1,
    "WGL_ARB_make_current_read" => 1,
    "WGL_ARB_pbuffer" => 1,
    "WGL_ARB_pixel_format" => 1,
    "WGL_ARB_render_texture" => 1,
    "WGL_EXT_extensions_string" => 1,
    "WGL_EXT_swap_control" => 1,
    "WGL_NV_vertex_array_range" => 1,
    "WGL_WINE_pixel_format_passthrough" => 1,
    "WGL_WINE_query_renderer" => 1,
   );

my %enums;

my %supported_apis =
    (
     "gl" => 1,
    );

sub is_supported_api($)
{
    my $api = shift;
    foreach my $i (split /\|/, $api)
    {
        return 1 if defined $supported_apis{$i};
    }
    return 0;
}

sub parse_file($$)
{
    my ($file, $generate_enums) = @_;
    my $xml = XML::LibXML->load_xml( location => $file );
    my %functions;

    # save all functions
    foreach my $command ($xml->findnodes("/registry/commands/command"))
    {
        my $proto = @{$command->findnodes("./proto")}[0];
        my $name = @{$command->findnodes("./proto/name")}[0];
        $proto->removeChild( $name );
        my @params = $command->findnodes("./param");
        $functions{$name->textContent()} = [ $proto, \@params ];
    }

    # save all enums (only GL)
    if ($generate_enums)
    {
        foreach my $enum ($xml->findnodes("/registry/enums/enum"))
        {
            $enums{$enum->{name}} = $enum->{value};
        }
    }

    # save all types
    foreach my $type ($xml->findnodes("/registry/types/type"))
    {
        next if $type->{api};
        my $name = @{$type->findnodes("./name")}[0];
        next unless $name;
        $name = $name->textContent;
        push @gl_types, $name unless $gl_types{$name};
        $gl_types{$name} = $type;
    }

    # generate norm functions
    foreach my $feature ($xml->findnodes("/registry/feature"))
    {
        if ($feature->{api} eq "wgl")
        {
            foreach my $cmd ($feature->findnodes("./require/command"))
            {
                my $name = $cmd->{name};
                if (defined $remapped_wgl_functions{$name})
                {
                    next unless $remapped_wgl_functions{$name};
                    $name = $remapped_wgl_functions{$name};
                }
                $wgl_functions{$name} = $functions{$cmd->{name}};
            }
        }
        next unless defined $norm_categories{$feature->{name}};
        foreach my $cmd ($feature->findnodes("./require/command"))
        {
            $norm_functions{$cmd->{name}} = $functions{$cmd->{name}};
        }
    }

    # generate extension functions from norm functions, if they are newer than the category
    foreach my $feature ($xml->findnodes("/registry/feature"))
    {
        next if defined $norm_categories{$feature->{name}};
        next unless is_supported_api( $feature->{api} );
        foreach my $cmd ($feature->findnodes("./require/command"))
        {
            my $name = $cmd->{name};
            next if $norm_functions{$name} || $ext_functions{$name};
            $ext_functions{$name} = [ $functions{$name}[0], $functions{$name}[1], [ $feature->{name} ] ];
        }
    }

    # generate extension functions
    foreach my $ext ($xml->findnodes("/registry/extensions/extension"))
    {
        if ($ext->{supported} eq "wgl")
        {
            next unless defined $supported_wgl_extensions{$ext->{name}};
            foreach my $cmd ($ext->findnodes("./require/command"))
            {
                my $name = $cmd->{name};
                $ext_functions{$name} = [ $functions{$name}[0], $functions{$name}[1], [ $ext->{name} ] ];
            }
            next;
        }
        next unless is_supported_api( $ext->{supported} );
        foreach my $req ($ext->findnodes("./require"))
        {
            next unless !$req->{api} || $req->{api} eq "gl";
            foreach my $cmd ($req->findnodes("./command"))
            {
                my $name = $cmd->{name};
                next if $norm_functions{$name};
                if (!$ext_functions{$name})
                {
                    $ext_functions{$name} = [ $functions{$name}[0], $functions{$name}[1], [ $ext->{name} ] ];
                }
                else
                {
                    push @{$ext_functions{$name}->[2]}, $ext->{name};
                }
            }
        }
    }
}

parse_file( "gl.xml", 1 );
parse_file( "wgl.xml", 0 );
parse_file( "winegl.xml", 1 );

#
# Get the current wgl_driver.h version
#
my $wgl_version = 0;
open HEADER, "<$wgl_driver_file" or die "cannot open $wgl_driver_file";
while (<HEADER>)
{
    next unless /^#define WINE_WGL_DRIVER_VERSION (\d+)/;
    $wgl_version = $1;
    last;
}
close HEADER;

#
# Generate the wgl_driver.h file
#
open HEADER, ">$wgl_driver_file" or die "cannot create $wgl_driver_file";
print HEADER "/* Automatically generated from http://www.opengl.org/registry files; DO NOT EDIT! */\n\n";
print HEADER "#ifndef __WINE_WGL_DRIVER_H\n";
print HEADER "#define __WINE_WGL_DRIVER_H\n\n";
print HEADER "#ifndef WINE_GLAPI\n";
print HEADER "#define WINE_GLAPI\n";
print HEADER "#endif\n\n";

printf HEADER "#define WINE_WGL_DRIVER_VERSION %u\n\n", $wgl_version + 1;

print HEADER "struct wgl_context;\n";
print HEADER "struct wgl_pbuffer;\n\n";

print HEADER "struct opengl_funcs\n{\n";
print HEADER "    struct\n    {\n";
foreach (sort keys %wgl_functions)
{
    next unless defined $supported_wgl_functions{$_};
    print HEADER get_func_proto("        %-10s (WINE_GLAPI *p_%s)(%s);\n", $_, $wgl_functions{$_});
}
print HEADER "    } wgl;\n\n";

print HEADER "    struct\n    {\n";
foreach (sort keys %norm_functions)
{
    next if $_ eq "glDebugEntry";
    print HEADER get_func_proto("        %-10s (WINE_GLAPI *p_%s)(%s);\n", $_, $norm_functions{$_});
}
print HEADER "    } gl;\n\n";

print HEADER "    struct\n    {\n";
foreach (sort keys %ext_functions)
{
    print HEADER get_func_proto("        %-10s (WINE_GLAPI *p_%s)(%s);\n", $_, $ext_functions{$_});
}
print HEADER "    } ext;\n";
print HEADER "};\n\n";

print HEADER "#define ALL_WGL_FUNCS";
foreach (sort keys %norm_functions)
{
    next if $_ eq "glDebugEntry";
    printf HEADER " \\\n    USE_GL_FUNC(\%s)", $_;
}
print HEADER "\n\n";

print HEADER "extern struct opengl_funcs * CDECL __wine_get_wgl_driver( HDC hdc, UINT version );\n";
print HEADER "extern BOOL CDECL __wine_set_pixel_format( HWND hwnd, int format );\n\n";
print HEADER "#endif /* __WINE_WGL_DRIVER_H */\n";
close HEADER;

#
# Generate the wgl.h file
#
open HEADER, ">$wgl_file" or die "cannot create $wgl_file";
print HEADER "/* Automatically generated from http://www.opengl.org/registry files; DO NOT EDIT! */\n\n";
print HEADER "#ifndef __WINE_WGL_H\n";
print HEADER "#define __WINE_WGL_H\n\n";

print HEADER "#ifndef GLAPIENTRY\n";
print HEADER "#define GLAPIENTRY __stdcall\n";
print HEADER "#endif\n\n";

print HEADER "#undef near\n";
print HEADER "#undef far\n\n";

foreach (@gl_types)
{
    printf HEADER $gl_types{$_}->textContent() . "\n";
}
print HEADER "\n";

my $maxlen = 1;
foreach (keys %enums) { $maxlen = length($_) if length($_) > $maxlen; }
foreach (sort keys %enums)
{
    printf HEADER "#define %-*s %s\n", $maxlen, $_, $enums{$_};
}
print HEADER "\n";

foreach (sort keys %norm_functions)
{
    printf HEADER "%s;\n", get_func_proto("%-10s GLAPIENTRY %s(%s)", $_, $norm_functions{$_});
}

print HEADER "\n#endif /* __WINE_WGL_H */\n";
close HEADER;

#
# Now, generate the output files. First, the spec file.
#
open(SPEC, ">$spec_file") or die "cannot create $spec_file";

foreach (sort keys %norm_functions) {
    printf SPEC "%s\n", generate_spec_entry( $_, $norm_functions{$_} );
}
foreach (sort keys %wgl_functions) {
    printf SPEC "%s\n", generate_spec_entry( $_, $wgl_functions{$_} );
}

close(SPEC);

#
# After the spec file, the opengl_norm.c file
#
open(NORM, ">$norm_file") or die "cannot create $norm_file";
print NORM "
/* Auto-generated file... Do not edit ! */

#include \"config.h\"
#include <stdarg.h>
#include \"winternl.h\"
#include \"wingdi.h\"
#include \"wine/wgl.h\"
#include \"wine/wgl_driver.h\"
#include \"wine/debug.h\"

WINE_DEFAULT_DEBUG_CHANNEL(opengl);
";

foreach (sort keys %norm_functions) {
    my $string = GenerateThunk($_, $norm_functions{$_}, "gl");
    print NORM "\n$string" if $string;
}

foreach (sort keys %wgl_functions) {
    next unless defined $supported_wgl_functions{$_};
    print NORM generate_null_func($_, $wgl_functions{$_});
}
foreach (sort keys %norm_functions) {
    print NORM generate_null_func($_, $norm_functions{$_});
}
foreach (sort keys %ext_functions) {
    print NORM generate_null_func($_, $ext_functions{$_});
}

print NORM "\nstruct opengl_funcs null_opengl_funcs =\n{\n    {\n";
foreach (sort keys %wgl_functions)
{
    next unless defined $supported_wgl_functions{$_};
    print NORM "        null_$_,\n";
}
print NORM "    },\n    {\n";
foreach (sort keys %norm_functions) { print NORM "        null_$_,\n" unless $_ eq "glDebugEntry"; }
print NORM "    },\n    {\n";
foreach (sort keys %ext_functions) { print NORM "        null_$_,\n"; }
print NORM "    }\n};\n";

close(NORM);

#
# Finally, more complex, the opengl_ext.c file
#
open(EXT, ">$ext_file") or die "cannot create $ext_file";
print EXT "
/* Auto-generated file... Do not edit ! */

#include \"config.h\"
#include <stdarg.h>
#include \"opengl_ext.h\"
#include \"winternl.h\"
#include \"wingdi.h\"
#include \"wine/wgl.h\"
#define WGL_WGLEXT_PROTOTYPES
#include \"wine/wglext.h\"
#include \"wine/wgl_driver.h\"
#include \"wine/debug.h\"

WINE_DEFAULT_DEBUG_CHANNEL(opengl);

";

# The thunks themselves....
my $count = keys %ext_functions;
print EXT "const int extension_registry_size = $count;\n";
foreach (sort keys %ext_functions) {
    my $string = GenerateThunk($_, $ext_functions{$_}, "ext");
    if ($string =~ /DECLSPEC_HIDDEN/) {
        print EXT "\n$string";
    } else {
        print EXT "\nstatic $string" if $string;
    }
}

# Then the table giving the string <-> function correspondence */
print EXT "\nconst OpenGL_extension extension_registry[$count] = {\n";
my $i = 0;
foreach (sort keys %ext_functions) {
    my $func_ref = $ext_functions{$_};
    printf EXT "  { \"%s\", \"%s\", %s }", $_, join(" ", sort @{$func_ref->[2]}), $_;
    if ($i != $count-1) {
        print EXT ",";
    }
    $i++;
    print EXT "\n";
}
print EXT "};\n";

close(EXT);