#!/usr/bin/perl

# Copyright 2001-2012, Paul Johnson (paul@pjcj.net)

# This software is free.  It is licensed under the same terms as Perl itself.

# The latest version of this software should be available from my homepage:
# http://www.pjcj.net

require 5.6.1;

use strict;
use warnings;

our $VERSION = '0.96'; # VERSION

use Devel::Cover::DB;

use File::Path;
use File::Spec;
use Getopt::Long;
use Pod::Usage;

my $Options =
{
    db     => "cover_db",
    merge  => 1,
};

sub get_options
{
    die "Bad option" unless
    GetOptions($Options,                # Store the options in the Options hash.
               qw(
                   db=s
                   help|h!
                   info|i!
                   merge!
                   version|v!
                 ));
    print "$0 version " . __PACKAGE__->VERSION . "\n" and exit 0
        if $Options->{version};
    pod2usage(-exitval => 0, -verbose => 0)  if $Options->{help};
    pod2usage(-exitval => 0, -verbose => 2)  if $Options->{info};
}

sub add_cover
{
    my ($file) = @_;
    my ($vol, $dir) = File::Spec->splitpath(File::Spec->rel2abs($file));
    $dir = File::Spec->catpath($vol, $dir);

    my $f = $file;
    $f =~ s/.gcov$//;

    my %run;
    $run{collected} = ["statement"];
    $run{start} = $run{finish} = time;
    my $structure = Devel::Cover::DB::Structure->new;
    $structure->add_criteria("statement");
    $structure->add_criteria("branch");

    my $statement_re = qr/^\s*([-0-9#]+):\s*(\d+):(.*)/;
    my $branch_re    = qr/^branch\s+(\d+)\s+(?:taken|never)\s+(\w+)/;

    my ($line, $text);

    open F, $file or die "Can't open $file: $!\n";
    gcov_line: while (my $gcov_text = <F>)
    {
        # print "Processing line [$gcov_text]\n";
        if ($gcov_text =~ /^[^:]+:[^:]+:Source:(.*)$/)
        {
            $f = $1;
            $f = File::Spec->abs2rel(File::Spec->catfile($dir, $f))
                unless File::Spec->file_name_is_absolute($f);
        }
        unless (defined $run{digests}{$f})
        {
            unless (-f $f)
            {
                warn "no source $f found for $file\n";
                close F or die "Can't close $file: $!\n";
                return;
            }
            $run{digests}{$f} = $structure->set_file($f);
        }
        if ($gcov_text =~ $statement_re)
        {
            my $count = $1;
            $line = $2;
            $text = $3;

            next if $count eq "-";
            $count = 0 if $count eq "#####";

            # print "$f:$line - $count\n";
            push @{$run{count}{$f}{statement}}, $count;
            $structure->add_statement($f, $line);
        }
        elsif ($gcov_text =~ $branch_re)
        {
            my @branches;
            # look for:
            #     branch  0 taken 0 (fallthrough)
            #     branch  1 taken 19
            #     branch  0 never executed
            #     branch  1 never executed
            while ($gcov_text =~ $branch_re)
            {
                push @branches, $2 eq "executed" ? 0 : $2;
                $gcov_text = <F>;
            }
            # print "branches on $f:$line are: @branches\n";

            if (@branches == 2)
            {
                $structure->add_branch($f, [ $line, { text => $text } ]);
                push @{$run{count}{$f}{branch}}, \@branches;
            }
            else
            {
                warn "gcov2perl: Warning: ignoring branch with ",
                     scalar @branches, " targets at $f:$line $text\n";
            }
            redo gcov_line;  # process the line after the branch data
        }
    }
    close F or die "Can't close $file: $!\n";

    my $run   = $run{start} . ".$$." . sprintf "%05d", rand 2 ** 16;
    my $db    = $Options->{db};
    my $cover = Devel::Cover::DB->new
    (
        base      => $db,
        runs      => { $run => \%run },
        structure => $structure,
    );

    $db .= "/runs";
    mkpath $db unless -d $db;
    $db .= "/$run";

    $cover->{db} = $db;

    print STDOUT "gcov2perl: Writing coverage database to $db\n";
    $cover->write;
}

sub main
{
    get_options;
    add_cover $_ for @ARGV;
}

main

__END__

=head1 NAME

gcov2perl - convert gcov files to Devel::Cover databases

=head1 VERSION

version 0.96

=head1 SYNOPSIS

 gcov2perl -h -i -v -db database gcov_files

=head1 DESCRIPTION

Convert gcov files to Devel::Cover databases.

=head1 OPTIONS

The following command line options are supported:

 -db database    - specify the database to use

 -h -help        - show help
 -i -info        - show documentation
 -v -version     - show version

=head1 DETAILS

To obtain coverage of XS files they must first be compiled with the appropriate
options.  In a standard Makefile environment, such as that created by
ExtUtils::MakeMaker, this can be accomplished with the command:

 HARNESS_PERL_SWITCHES=-MDevel::Cover make test \
   CCFLAGS=-O0\ -fprofile-arcs\ -ftest-coverage \
   OTHERLDFLAGS=-fprofile-arcs\ -ftest-coverage

If you have already built your object files it may be necessary to run make
clean first, or to find some other way to ensure that they get rebuilt with the
options gcov requires.

Now the code coverage data has been collected C<gcov> needs to be run:

 gcov Mylib.xs

This will create one or more gcov files on which you can run C<gcov2perl>:

 gcov2perl Mylib.xs.gcov

Finally, C<cover> should be run as usual with any options required:

 cover

If you are running everything with standard options, you can do all this with
one command:

 cover -test

=head1 EXIT STATUS

The following exit values are returned:

 0   All files converted successfully
 >0  An error occurred.

=head1 SEE ALSO

 Devel::Cover

=head1 BUGS

Huh?

=head1 LICENCE

Copyright 2001-2012, Paul Johnson (paul@pjcj.net)

This software is free.  It is licensed under the same terms as Perl itself.

The latest version of this software should be available from my homepage:
http://www.pjcj.net

=cut