#!/usr/bin/perl

use strict;

# This script is to be run by AC_CONFIG_COMMANDS in configure.ac.

# USAGE:

#     AC_CONFIG_COMMANDS([prefix-config],[perl cmd_prefix_config_h.pl PREFIX input_config.h output_config.h])

#

# The script will read "input_config.h", and write "output_config.h", adding prefix to every defined macros. This script is a replacement to AX_PREFIX_CONFIG_H.

sub add_prefix {

    my ($name, $prefix) = @_;

    if($name=~/^(inline|const|restrict)/){

        # leave c99 keywords alone

    }

    elsif($name=~/^_/){

        # leave underscore keywords alone, e.g _MINIX

    }

    elsif($name=~/^$prefix\_/i){

        # avoid double prefix

    }

    elsif($name=~/^[A-Z0-9_]+$/){

        $name = uc($prefix)."_$name";

    }

    else{

        $name = "_".lc($prefix)."_$name";

    }

    return $name;

}

my ($prefix, $config_in, $config_out)=@ARGV;

if(!$prefix){

    die "missing prefix!\n";

}

if(!$config_in){

    $config_in = "config.h";

}

if(!$config_out){

    $config_out = $config_in;

}

my @lines;

open In, "$config_in" or die "Can't open $config_in.\n";

while(<In>){

    if(/^#define\s+(\w+)\s*(.+)/){

        my $name = add_prefix($1, $prefix);

        push @lines, "#ifndef $name\n";

        push @lines, "#define $name $2\n";

        push @lines, "#endif\n";

        next;

    }

    elsif(/^\/\*\s*#undef (\w+)/){

        my $name = add_prefix($1, $prefix);

        push @lines, "/* #undef $name */\n";

        next;

    }

    push @lines, $_;

}

close In;

my $DEFH=uc($config_out);

$DEFH=~s/\W/_/g;

open Out, ">$config_out" or die "Can't write $config_out.\n";

print Out "#ifndef $DEFH\n";

print Out "#define $DEFH 1\n\n";

print Out "\x2f* $config_out. Generated automatically at end of configure. *\x2f\n";

print Out @lines;

print Out "\x2f* once: $DEFH *\x2f\n";

print Out "#endif\n";

close Out;