#!/usr/bin/env perl
#
# (C) Copyright IBM Corporation 2006.
#       Released under GPL v2.
#       Author : Ram Pai (linuxram@us.ibm.com)
#
# Usage: export_report.pl -k Module.symvers [-o report_file ] -f *.mod.c
#

use warnings;
use Getopt::Std;
use strict;

sub numerically {
        my $no1 = (split /\s+/, $a)[1];
        my $no2 = (split /\s+/, $b)[1];
        return $no1 <=> $no2;
}

sub alphabetically {
        my ($module1, $value1) = @{$a};
        my ($module2, $value2) = @{$b};
        return $value1 <=> $value2 || $module2 cmp $module1;
}

sub print_depends_on {
        my ($href) = @_;
        print "\n";
        for my $mod (sort keys %$href) {
                my $list = $href->{$mod};
                print "\t$mod:\n";
                foreach my $sym (sort numerically @{$list}) {
                        my ($symbol, $no) = split /\s+/, $sym;
                        printf("\t\t%-25s\n", $symbol);
                }
                print "\n";
        }
        print "\n";
        print "~"x80 , "\n";
}

sub usage {
        print "Usage: @_ -h -k Module.symvers  [ -o outputfile ] \n",
              "\t-f: treat all the non-option argument as .mod.c files. ",
              "Recommend using this as the last option\n",
              "\t-h: print detailed help\n",
              "\t-k: the path to Module.symvers file. By default uses ",
              "the file from the current directory\n",
              "\t-o outputfile: output the report to outputfile\n";
        exit 0;
}

sub collectcfiles {
    my @file;
    while (<.tmp_versions/*.mod>) {
        open my $fh, '<', $_ or die "cannot open $_: $!\n";
        push (@file,
              grep s/\.ko/.mod.c/,      # change the suffix
              grep m/.+\.ko/,           # find the .ko path
              <$fh>);                   # lines in opened file
    }
    chomp @file;
    return @file;
}

my (%SYMBOL, %MODULE, %opt, @allcfiles);

if (not getopts('hk:o:f',\%opt) or defined $opt{'h'}) {
        usage($0);
}

if (defined $opt{'f'}) {
        @allcfiles = @ARGV;
} else {
        @allcfiles = collectcfiles();
}

if (not defined $opt{'k'}) {
        $opt{'k'} = "Module.symvers";
}

open (my $module_symvers, '<', $opt{'k'})
    or die "Sorry, cannot open $opt{'k'}: $!\n";

if (defined $opt{'o'}) {
    open (my $out, '>', $opt{'o'})
        or die "Sorry, cannot open $opt{'o'} $!\n";

    select $out;
}

#
# collect all the symbols and their attributes from the
# Module.symvers file
#
while ( <$module_symvers> ) {
        chomp;
        my (undef, $symbol, $module, $gpl) = split;
        $SYMBOL { $symbol } =  [ $module , "0" , $symbol, $gpl];
}
close($module_symvers);

#
# collect the usage count of each symbol.
#
my $modversion_warnings = 0;

foreach my $thismod (@allcfiles) {
        my $module;

        unless (open ($module, '<', $thismod)) {
                warn "Sorry, cannot open $thismod: $!\n";
                next;
        }

        my $state=0;
        while ( <$module> ) {
                chomp;
                if ($state == 0) {
                        $state = 1 if ($_ =~ /static const struct modversion_info/);
                        next;
                }
                if ($state == 1) {
                        $state = 2 if ($_ =~ /__attribute__\(\(section\("__versions"\)\)\)/);
                        next;
                }
                if ($state == 2) {
                        if ( $_ !~ /0x[0-9a-f]+,/ ) {
                                next;
                        }
                        my $sym = (split /([,"])/,)[4];
                        my ($module, $value, $symbol, $gpl) = @{$SYMBOL{$sym}};
                        $SYMBOL{ $sym } =  [ $module, $value+1, $symbol, $gpl];
                        push(@{$MODULE{$thismod}} , $sym);
                }
        }
        if ($state != 2) {
                warn "WARNING:$thismod is not built with CONFIG_MODVERSIONS enabled\n";
                $modversion_warnings++;
        }
        close($module);
}

print "\tThis file reports the exported symbols usage patterns by in-tree\n",
        "\t\t\t\tmodules\n";
printf("%s\n\n\n","x"x80);
printf("\t\t\t\tINDEX\n\n\n");
printf("SECTION 1: Usage counts of all exported symbols\n");
printf("SECTION 2: List of modules and the exported symbols they use\n");
printf("%s\n\n\n","x"x80);
printf("SECTION 1:\tThe exported symbols and their usage count\n\n");
printf("%-25s\t%-25s\t%-5s\t%-25s\n", "Symbol", "Module", "Usage count",
        "export type");

#
# print the list of unused exported symbols
#
foreach my $list (sort alphabetically values(%SYMBOL)) {
        my ($module, $value, $symbol, $gpl) = @{$list};
        printf("%-25s\t%-25s\t%-10s\t", $symbol, $module, $value);
        if (defined $gpl) {
                printf("%-25s\n",$gpl);
        } else {
                printf("\n");
        }
}
printf("%s\n\n\n","x"x80);

printf("SECTION 2:\n\tThis section reports export-symbol-usage of in-kernel
modules. Each module lists the modules, and the symbols from that module that
it uses.  Each listed symbol reports the number of modules using it\n");

print "\nNOTE: Got $modversion_warnings CONFIG_MODVERSIONS warnings\n\n"
    if $modversion_warnings;

print "~"x80 , "\n";
for my $thismod (sort keys %MODULE) {
        my $list = $MODULE{$thismod};
        my %depends;
        $thismod =~ s/\.mod\.c/.ko/;
        print "\t\t\t$thismod\n";
        foreach my $symbol (@{$list}) {
                my ($module, $value, undef, $gpl) = @{$SYMBOL{$symbol}};
                push (@{$depends{"$module"}}, "$symbol $value");
        }
        print_depends_on(\%depends);
}