source: branches/samba-3.5.x/lib/tdb/script/mksigs.pl

#!/usr/bin/perl

# mksigs.pl - extract signatures from C headers
#
# Copyright (C) Michael Adam 2009
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 3 of the License, or (at your option)
# any later version.
#
# This program 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 General Public License for
# more details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, see <http://www.gnu.org/licenses/>.

# USAGE:  cat $header_files | mksigs.pl > $signature_file
#
# The header files to parse are read from stdin.
# The output is in a form as produced by gcc with the -aux-info switch
# and printed to stdout.

use strict;
use warnings;

my $in_comment = 0;
my $extern_C_block = 0;

while (my $LINE = <>) {
        # find end of started multi-line-comment
        if ($in_comment) {
                if ($LINE =~ /^.*?\*\/(.*)$/) {
                        $LINE = $1;
                        $in_comment = 0;
                } else {
                        # whole line within comment
                        next;
                }
        }

        # strip C++-style comments
        $LINE =~ s/^(.*?)\/\/.*$/$1/;

        # strip in-line-comments:
        while ($LINE =~ /\/\*.*?\*\//) {
                $LINE =~ s/\/\*.*?\*\///;
        }

        # find starts of multi-line-comments
        if ($LINE =~ /^(.*)\/\*/) {
                $in_comment = 1;
                $LINE = $1;
        }

        # skip empty lines
        next if $LINE =~ /^\s*$/;

        # remove leading spaces
        $LINE =~ s/^\s*(.*)$/$1/;

        # concatenate lines split with "\" (usually macro defines)
        while ($LINE =~ /^(.*?)\s+\\$/) {
                my $LINE2 = <>;
                $LINE = $1;
                $LINE2 =~ s/^\s*(.*)$/$1/;
                $LINE .= " " . $LINE2;
        }

        # remove all preprocessor directives
        next if ($LINE =~ /^#/);

        if ($LINE =~ /^extern\s+"C"\s+\{/) {
                $extern_C_block = 1;
                next;
        }

        if (($LINE =~ /^[^\{]*\}/) and $extern_C_block) {
                $extern_C_block = 0;
                next;
        }

        $LINE =~ s/^extern\s//;

        # concatenate braces stretched over multiple lines
        # (from structs or enums)
        my $REST = $LINE;
        my $braces = 0;
        while (($REST =~ /[\{\}]/) or ($braces)) {
                while ($REST =~ /[\{\}]/) {
                        # collect opening
                        while ($REST =~ /^[^\{\}]*\{(.*)$/) {
                                $braces++;
                                $REST = $1;
                        }

                        # collect closing
                        while ($REST =~ /^[^\{\}]*\}(.*)$/) {
                                $braces--;
                                $REST = $1;
                        }
                }

                # concatenate if not balanced
                if ($braces) {
                        if (my $LINE2 = <>) {
                                $LINE2 =~ s/^\s*(.*)$/$1/;
                                chomp($LINE);
                                $LINE .= " " . $LINE2;
                                chomp $REST;
                                $REST .= " " . $LINE2;
                        } else {
                                print "ERROR: unbalanced braces ($braces)\n";
                                last;
                        }
                }
        }

        # concetenate function prototypes that stretch over multiple lines
        $REST = $LINE;
        my $parenthesis = 0;
        while (($REST =~ /[\(\)]/) or ($parenthesis)) {
                while ($REST =~ /[\(\)]/) {
                        # collect opening
                        while ($REST =~ /^[^\(\)]*\((.*)$/) {
                                $parenthesis++;
                                $REST = $1;
                        }

                        # collect closing
                        while ($REST =~ /^[^\(\)]*\)(.*)$/) {
                                $parenthesis--;
                                $REST = $1;
                        }
                }

                # concatenate if not balanced
                if ($parenthesis) {
                        if (my $LINE2 = <>) {
                                $LINE2 =~ s/^\s*(.*)$/$1/;
                                chomp($LINE);
                                $LINE .= " " . $LINE2;
                                chomp($REST);
                                $REST .= " " . $LINE2;
                        } else {
                                print "ERROR: unbalanced parantheses ($parenthesis)\n";
                                last;
                        }
                }
        }

        next if ($LINE =~ /^typedef\s/);
        next if ($LINE =~ /^enum\s+[^\{\(]+\s+\{/);
        next if ($LINE =~ /^struct\s+[^\{\(]+\s+\{.*\}\s*;/);
        next if ($LINE =~ /^struct\s+[a-zA-Z0-9_]+\s*;/);

        # remove trailing spaces
        $LINE =~ s/(.*?)\s*$/$1/;

        $LINE =~ s/^(.*\))\s+PRINTF_ATTRIBUTE\([^\)]*\)(\s*[;,])/$1$2/;
        $LINE =~ s/^(.*\))\s*[a-zA-Z0-9_]+\s*;$/$1;/;

        # remove parameter names - slightly too coarse probably
        $LINE =~ s/([\s\(]\*?)[_0-9a-zA-Z]+\s*([,\)])/$1$2/g;

        # remedy (void) from last line
        $LINE =~ s/\(\)/(void)/g;

        # normalize spaces
        $LINE =~ s/\s*\)\s*/)/g;
        $LINE =~ s/\s*\(\s*/ (/g;
        $LINE =~ s/\s*,\s*/, /g;

        # normalize unsigned
        $LINE =~ s/([\s,\(])unsigned([,\)])/$1unsigned int$2/g;

        # normalize bool
        $LINE =~ s/(\b)bool(\b)/_Bool/g;

        print $LINE . "\n";
}