#!/usr/bin/env perl

  # SPDX-License-Identifier: GPL-2.0-only

  #
  # (C) Copyright IBM Corporation 2006.

  #	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 "
  ";

  	for my $mod (sort keys %$href) {
  		my $list = $href->{$mod};

  		print "\t$mod:
  ";
  		foreach my $sym (sort numerically @{$list}) {
  			my ($symbol, $no) = split /\s+/, $sym;

  			printf("\t\t%-25s
  ", $symbol);

  		}
  		print "
  ";
  	}
  	print "
  ";
  	print "~"x80 , "
  ";
  }
  
  sub usage {
          print "Usage: @_ -h -k Module.symvers  [ -o outputfile ] 
  ",
  	      "\t-f: treat all the non-option argument as .mod.c files. ",
  	      "Recommend using this as the last option
  ",
  	      "\t-h: print detailed help
  ",
  	      "\t-k: the path to Module.symvers file. By default uses ",
  	      "the file from the current directory
  ",
  	      "\t-o outputfile: output the report to outputfile
  ";
  	exit 0;
  }
  
  sub collectcfiles {

      my @file;

      open my $fh, '< modules.order' or die "cannot open modules.order: $!
  ";
      while (<$fh>) {
  	s/\.ko$/.mod.c/;
  	push (@file, $_)

      }

      close($fh);

      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'}: $!
  ";

  
  if (defined $opt{'o'}) {

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

  }

  #
  # collect all the symbols and their attributes from the
  # Module.symvers file
  #

  while ( <$module_symvers> ) {

  	chomp;

  	my (undef, $symbol, $module, $gpl, $namespace) = split('\t');

  	$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: $!
  ";

  		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
  ";
  		$modversion_warnings++;

  	}

  	close($module);

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

  print "
  NOTE: Got $modversion_warnings CONFIG_MODVERSIONS warnings
  
  "
      if $modversion_warnings;

  print "~"x80 , "
  ";

  for my $thismod (sort keys %MODULE) {
  	my $list = $MODULE{$thismod};

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