#!/usr/bin/env perl
#
#   Copyright (c) International Business Machines  Corp., 2002,2012
#
#   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 2 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/>.
#
#
# lcov
#
#   This is a wrapper script which provides a single interface for accessing
#   LCOV coverage data.
#
#
# History:
#   2002-08-29 created by Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>
#                         IBM Lab Boeblingen
#   2002-09-05 / Peter Oberparleiter: implemented --kernel-directory +
#                multiple directories
#   2002-10-16 / Peter Oberparleiter: implemented --add-tracefile option
#   2002-10-17 / Peter Oberparleiter: implemented --extract option
#   2002-11-04 / Peter Oberparleiter: implemented --list option
#   2003-03-07 / Paul Larson: Changed to make it work with the latest gcov
#                kernel patch.  This will break it with older gcov-kernel
#                patches unless you change the value of $gcovmod in this script
#   2003-04-07 / Peter Oberparleiter: fixed bug which resulted in an error
#                when trying to combine .info files containing data without
#                a test name
#   2003-04-10 / Peter Oberparleiter: extended Paul's change so that LCOV
#                works both with the new and the old gcov-kernel patch
#   2003-04-10 / Peter Oberparleiter: added $gcov_dir constant in anticipation
#                of a possible move of the gcov kernel directory to another
#                file system in a future version of the gcov-kernel patch
#   2003-04-15 / Paul Larson: make info write to STDERR, not STDOUT
#   2003-04-15 / Paul Larson: added --remove option
#   2003-04-30 / Peter Oberparleiter: renamed --reset to --zerocounters
#                to remove naming ambiguity with --remove
#   2003-04-30 / Peter Oberparleiter: adjusted help text to include --remove
#   2003-06-27 / Peter Oberparleiter: implemented --diff
#   2003-07-03 / Peter Oberparleiter: added line checksum support, added
#                --no-checksum
#   2003-12-11 / Laurent Deniel: added --follow option
#   2004-03-29 / Peter Oberparleiter: modified --diff option to better cope with
#                ambiguous patch file entries, modified --capture option to use
#                modprobe before insmod (needed for 2.6)
#   2004-03-30 / Peter Oberparleiter: added --path option
#   2004-08-09 / Peter Oberparleiter: added configuration file support
#   2008-08-13 / Peter Oberparleiter: added function coverage support
#   2020-09-15 / Henry Cox:  refactor to use common utilities.
#

use strict;
use warnings;
use File::Basename qw(basename dirname);
use File::Path qw(mkpath);
use File::Find;
use File::Spec::Functions qw /abs2rel canonpath catdir catfile catpath
                              file_name_is_absolute rootdir splitdir splitpath/;
use Cwd qw /abs_path getcwd/;
use POSIX qw (floor);
use Storable;
use Time::HiRes;    # for profiling

use lib "/usr/lib/lcov";
use lcovutil qw ($tool_name $tool_dir $lcov_version $lcov_url
                 define_errors parse_ignore_errors ignorable_error
                 info set_info_callback init_verbose_flag $verbose
                 $br_coverage $func_coverage
                 debug $debug $devnull $dirseparator
                 die_handler warn_handler abort_handler
                 create_temp_dir temp_cleanup
                 summarize_cov_filters
                 $FILTER_BRANCH_NO_COND $FILTER_LINE_CLOSE_BRACE @cov_filter

                 @exclude_file_patterns @include_file_patterns %excluded_files
                 warn_file_patterns summarize_messages
                 %lcovErrors $ERROR_GCOV $ERROR_SOURCE $ERROR_MISMATCH
                 $ERROR_BRANCH $ERROR_EMPTY $ERROR_FORMAT $ERROR_VERSION
                 $ERROR_UNUSED $ERROR_PACKAGE $ERROR_CORRUPT
                 $ERROR_PARALLEL report_parallel_error
                 system_no_output
                 rate get_overall_line

                 parseOptions
                 strip_directories transform_pattern
                 @extractVersionScript $verify_checksum
                 @comments

                 $maxParallelism $maxMemory
  );

# Directory containing gcov kernel files
our $gcov_dir;

# Internal constants
our $GKV_PROC       = 0;    # gcov-kernel data in /proc via external patch
our $GKV_SYS        = 1;    # gcov-kernel data in /sys via vanilla 2.6.31+
our @GKV_NAME       = ("external", "upstream");
our $pkg_gkv_file   = ".gcov_kernel_version";
our $pkg_build_file = ".build_directory";

# Branch data combination types
our $BR_SUB = 0;
our $BR_ADD = 1;

# Prototypes
sub print_usage(*);
sub check_options();
sub userspace_reset();
sub userspace_capture();
sub kernel_reset();
sub kernel_capture();
sub kernel_capture_initial();
sub package_capture();
sub add_traces();
sub merge_traces($$);
sub remove_file_patterns($);
sub list();
sub my_info(@);
set_info_callback(\&my_info);
sub setup_gkv();
sub lcov_geninfo(@);
sub create_package($$$;$);
sub summary();

# Global variables & initialization

our $directory;           # If set, capture from user-space directories in @ARGV
our $kernel_directory;    # If set, capture from kernel subdirs in @ARGV
our $add_tracefile;       # If set, combine tracefiles listed in @ARGV
our @intersect;           # glob patterns for intersect RHS
our @difference;          # glob patterns for difference RHS
our $list;                # If set, list contents of tracefile
our $reset;               # If set, reset all coverage data to zero
our $prune_testcases;     # If set, try to filter out useless tests that do not
                          # contribute new coverage or new coverpoints
our $output_filename;     # Name for file to write coverage data to
our $test_name = "";               # Test case name
our $cwd       = Cwd::getcwd();    # Current working directory
our $data_stdout;        # If set, indicates that data is written to stdout
our $follow;             # If set, indicates that find shall follow links
our $base_directory;     # Base directory (cwd of gcc during compilation)
our $compat_libtool;     # If set, indicates that libtool mode is to be enabled
our $no_compat_libtool;  # If set, indicates that libtool mode is to be disabled

our @gcov_tool;
our @large_files;        # handled sequentially in geninfo
our $initial;
our $captureAll;
our $no_recursion = 0;
our $to_package;
our $from_package;
our $maxdepth;
our $no_markers;
chomp($cwd);
our $gcov_gkv;           # gcov kernel support version found on machine
our $opt_derive_func_data;
our $opt_list_full_path;
our $opt_no_list_full_path;
our $opt_list_width        = 80;
our $opt_list_truncate_max = 20;
our $opt_external;
our $opt_summary;        # If set, summarize tracefiles listed in @ARGV
our $opt_compat;

#
# Code entry point
#

$SIG{__WARN__} = \&lcovutil::warn_handler;
$SIG{__DIE__}  = \&lcovutil::die_handler;
$SIG{'INT'}    = \&lcovutil::abort_handler;
$SIG{'QUIT'}   = \&lcovutil::abort_handler;

lcovutil::save_cmd_line(\@ARGV, "/usr/bin");

our @cmdArgs = @ARGV;

my %lcov_rc_params = ("lcov_gcov_dir"          => \$gcov_dir,
                      "lcov_list_full_path"    => \$opt_list_full_path,
                      "lcov_list_width"        => \$opt_list_width,
                      "lcov_list_truncate_max" => \$opt_list_truncate_max);

my %lcov_options = ("directory|d|di"     => \$directory,
                    "add-tracefile|a"    => \$add_tracefile,
                    "list|l"             => \$list,
                    "kernel-directory|k" => \$kernel_directory,
                    "extract|e=s"        => \$lcovutil::lcov_extract,
                    "remove|r=s"         => \$lcovutil::lcov_remove,
                    "capture|c"          => \$lcovutil::lcov_capture,
                    "output-file|o=s"    => \$output_filename,
                    "test-name|t=s"      => \$test_name,
                    "zerocounters|z"     => \$reset,
                    "follow|f"           => \$follow,
                    "base-directory|b=s" => \$base_directory,
                    "compat-libtool"     => \$compat_libtool,
                    "no-compat-libtool"  => \$no_compat_libtool,
                    "gcov-tool=s"        => \@gcov_tool,
                    'large-file=s'       => \@large_files,

                    "initial|i"         => \$initial,
                    "all"               => \$captureAll,
                    "no-recursion"      => \$no_recursion,
                    "to-package=s"      => \$to_package,
                    "from-package=s"    => \$from_package,
                    "no-markers"        => \$no_markers,
                    "derive-func-data"  => \$opt_derive_func_data,
                    "list-full-path"    => \$opt_list_full_path,
                    "no-list-full-path" => \$opt_no_list_full_path,
                    "external"          => \$opt_external,
                    "no-external"       => \$lcovutil::opt_no_external,
                    "summary"           => \$opt_summary,
                    "compat=s"          => \$opt_compat,
                    "prune-tests"       => \$prune_testcases,
                    "map-functions"     => \$AggregateTraces::function_mapping,

                    'intersect=s' => \@intersect,
                    'subtract=s'  => \@difference,);

# geninfo args might get passed to lcov for --capture mode - so we need to not croak on them
my %mergedRcOpts = (%lcov_rc_params, %lcovutil::geninfo_rc_opts);

# Parse command line options
if (!lcovutil::parseOptions(\%mergedRcOpts, \%lcov_options, \$output_filename))
{
    print(STDERR "Use $tool_name --help to get usage information\n");
    exit(1);
}

if (defined($no_compat_libtool)) {
    $compat_libtool    = $no_compat_libtool ? 0 : 1;
    $no_compat_libtool = undef;
}

if (defined($opt_no_list_full_path)) {
    $opt_list_full_path    = ($opt_no_list_full_path ? 0 : 1);
    $opt_no_list_full_path = undef;
}

if (defined($base_directory)) {
    push(@ReadCurrentSource::source_directories, $base_directory);
    push(@lcovutil::internal_dirs, $base_directory);
}
if (defined($opt_external)) {
    $lcovutil::opt_no_external = 0;
    $opt_external              = undef;
}

my $begin = Time::HiRes::gettimeofday();

if ($initial && !$lcovutil::lcov_capture) {
    lcovutil::ignorable_warning($lcovutil::ERROR_USAGE,
                          "'--initial' is ignored except in '--capture' mode.");
    $initial = undef;
}

if ($captureAll && $initial) {
    lcovutil::ignorable_warning($lcovutil::ERROR_USAGE,
                                "'--all' ignored when '--initial' is used.");
    $captureAll = undef;
}

# Check list width option
if ($opt_list_width <= 40) {
    die("lcov_list_width parameter out of range (needs to be " .
        "larger than 40)\n");
}

$follow   = $follow ? '-follow' : '';
$maxdepth = $no_recursion ? '-maxdepth 1' : '';

# --directory and --kernel-directory are mutually exclusive.
if ($directory && $kernel_directory) {
    $directory = undef;    # assume the user meant 'kernel' if ignored
    my $suffix =
        lcovutil::is_ignored($lcovutil::ERROR_USAGE) ?
        "\n\tContinuing with '--kernel-directory'." :
        '';
    lcovutil::ignorable_error($lcovutil::ERROR_USAGE,
        'only one of --directory (-d) or --kernel-directory (-k) should be specified.'
            . $suffix);
}

# Check for valid options
check_options();

# Mode flags that consume @ARGV as their input list
if (@ARGV &&
    !(  $lcovutil::lcov_extract ||
        $lcovutil::lcov_remove  ||
        @intersect              ||
        @difference             ||
        $opt_summary            ||
        $add_tracefile          ||
        $directory              ||
        $kernel_directory       ||
        $lcovutil::lcov_capture ||
        $list                   ||
        $reset)
) {
    die("Extra parameter found: '" .
        join(" ", @ARGV) .
        "'\n" . "Use $tool_name --help to get usage information\n");
}

if (!@ARGV) {
    if ($directory || $kernel_directory) {
        die("--" . ($directory ? "directory" : "kernel-directory") .
            " specified but no directories provided\n" .
            "Use $tool_name --help to get usage information\n");
    }
    foreach my $d ([$add_tracefile, '--add-tracefile'],
                   [$list, '--list'],
                   [$opt_summary, '--summary'],
                   [scalar(@intersect), '--intersect'],
                   [scalar(@difference), '--subtract'],
    ) {
        die($d->[1] . " specified but no tracefiles provided\n" .
            "Use $tool_name --help to get usage information\n")
            if ($d->[0]);
    }
}

if (defined($lcovutil::opt_no_external) &&
    !(defined($lcovutil::lcov_capture) && $lcovutil::lcov_capture != 0)) {
    lcovutil::ignorable_warning($lcovutil::ERROR_USAGE,
                  "'--no-external' is ignored except in 'lcov --capture|-c'\n");
    $lcovutil::opt_no_external = 0;
}

# Check for output filename
$data_stdout = !($output_filename && ($output_filename ne "-"));

if ($lcovutil::lcov_capture && $data_stdout) {
    # Option that tells geninfo to write to stdout
    $output_filename = "-";
}

# Determine kernel directory for gcov data
if (!$from_package &&
    !$directory &&
    !@ARGV      &&
    ($lcovutil::lcov_capture || $reset)) {
    ($gcov_gkv, $gcov_dir) = setup_gkv();
}

our $exit_code = 0;

my $trace;

eval {
    # Check for requested functionality
    if ($reset) {
        $data_stdout = 0;
        # Differentiate between user space and kernel reset
        if ($directory || @ARGV) {
            userspace_reset();
        } else {
            kernel_reset();
        }
    } elsif ($lcovutil::lcov_capture) {
        # Capture source can be user space, kernel or package
        if ($from_package) {
            package_capture();
        } elsif ($directory || (!$kernel_directory && @ARGV)) {
            userspace_capture();
        } else {
            if ($initial) {
                die("--initial cannot be used together with --to-package\n")
                    if (defined($to_package));
                kernel_capture_initial();
            } else {
                kernel_capture();
            }
        }
    } elsif ($add_tracefile) {
        if ($AggregateTraces::function_mapping) {
            $AggregateTraces::function_mapping = {};
            add_traces();

            my $file = InOutFile->out($output_filename);
            my $hdl  = $file->hdl();
            while (my ($key, $data) = each(%$AggregateTraces::function_mapping))
            {
                print($hdl $data->[0] . ": " . $key . "\n");
                foreach my $f (@{$data->[1]}) {
                    print($hdl "  $f\n");
                }
            }
        } elsif (defined($prune_testcases)) {
            my ($pruned, $merged) = add_traces();

            info("Pruned result: retained " .
                 scalar(@$pruned) . " of " .
                 scalar(@$merged) . " files\n");
            my $file = InOutFile->out($output_filename);
            my $hdl  = $file->hdl();
            print($hdl join("\n", @$pruned) . "\n");
        } else {
            $trace = add_traces();
        }
    } elsif ($lcovutil::lcov_remove) {
        # remove files matching patterns
        $trace = remove_file_patterns($lcovutil::lcov_remove);
    } elsif ($lcovutil::lcov_extract) {
        # kep only the files matching patterns
        $trace = remove_file_patterns($lcovutil::lcov_extract);
    } elsif ($list) {
        $data_stdout = 0;
        list();
    } elsif ($opt_summary) {
        $data_stdout = 0;
        $trace       = summary();
    } elsif (@intersect) {
        $trace = merge_traces(\@intersect, TraceInfo::INTERSECT);
    } elsif (@difference) {
        $trace = merge_traces(\@difference, TraceInfo::DIFFERENCE);
    }
};
if ($@) {
    $exit_code = 1;
    print(STDERR $@);
}

temp_cleanup();
chdir($cwd);

if (0 == $exit_code) {
    if (defined($trace)) {
        # the numbers do not reflect coverpoints in 'erased' functions.
        #  the issue is that we filter them out in the write operation - but
        #  we don't bother to read it back
        $trace->print_summary();
        $trace->checkCoverageCriteria();
        $exit_code = 1 if $CoverageCriteria::coverageCriteriaStatus;
        CoverageCriteria::summarize();
    } else {
        info("Done.\n") if (!$list && !$lcovutil::lcov_capture);
    }
    if (!defined($lcovutil::lcov_capture)) {
        lcovutil::warn_file_patterns()
            ;    # warn about unused include/exclude directives
        ReadCurrentSource::warn_sourcedir_patterns();
        summarize_cov_filters();
        summarize_messages();
    }
}
my $end = Time::HiRes::gettimeofday();
$lcovutil::profileData{total} = $end - $begin;

unless ($lcovutil::lcov_capture) {
    # if we executed 'geninfo' - then we saved the profile data from that process
    lcovutil::cleanup_callbacks();
    lcovutil::save_profile($output_filename ? $output_filename : "lcov");
}

# exit with non-zero status if --keep-going and some errors detected
$exit_code = 1
    if (0 == $exit_code &&
        lcovutil::saw_error());

exit($exit_code);

#
# print_usage(handle)
#
# Print usage information.
#

sub print_usage(*)
{
    local *HANDLE = $_[0];

    print(HANDLE <<END_OF_USAGE);
Usage: $tool_name [OPTIONS]

Use lcov to collect coverage data from either the currently running Linux
kernel or from a user space application. Specify the --directory option to
get coverage data for a user space program.

COMMON OPTIONS
  -h, --help                      Print this help, then exit
      --version                   Print version number, then exit
  -v, --verbose                   Increase verbosity level
  -q, --quiet                     Decrease verbosity level (e.g. to turn off
                                  progress messages)
      --debug                     Increase debug verbosity level
      --config-file FILENAME      Specify configuration file location
      --rc SETTING=VALUE          Override configuration file setting
      --ignore-errors ERRORS      Continue after ERRORS (see man page for
                                  full list of errors and their meaning)
      --keep-going                Do not stop if an error occurs
      --tempdir DIRNAME           Write temporary and intermediate data here
      --preserve                  Keep intermediate files for debugging

OPERATION
  -z, --zerocounters              Reset all execution counts to zero
  -c, --capture                   Capture coverage data
  -a, --add-tracefile PATTERN     Add contents of tracefiles matching glob PATTERN
  -e, --extract FILE PATTERN      Extract files matching PATTERN from FILE
  -r, --remove FILE PATTERN       Remove files matching PATTERN from FILE
  -l, --list FILE                 List contents of tracefile FILE
      --summary FILE              Show summary coverage data for tracefiles
      --prune-tests               List tracefiles contributing unique coverage
                                  data (requires --add-tracefile)
      --map-functions             List tracefiles with non-zero coverage for
                                  each function (requires --add-tracefile)
     --intersect PATTERN          Set intersection with tracefiles matching
                                  glob PATTERN
     --subtract PATTERN           Set difference with tracefiles matching
                                  glob PATTERN

OPTIONS
  -i, --initial                   Capture initial zero coverage data
  --all                           Capture from both .gcda and lone .gcno files
  -t, --test-name NAME            Specify test name to be stored with data
  -o, --output-file FILENAME      Write data to FILENAME instead of stdout
  -d, --directory DIR             Use .da files in DIR instead of kernel
  -f, --follow                    Follow links when searching .da files
  -k, --kernel-directory KDIR     Capture kernel coverage data only from KDIR
  -b, --base-directory DIR        Use DIR as base directory for relative paths
      --build-directory DIR       Search DIR for .gcno files (during capture)
      --path PATH                 Strip PATH from tracefile when applying diff
      --(no-)function-coverage    Enable (disable) function coverage collection
      --(no-)branch-coverage      Enable (disable) branch coverage collection
      --(no-)checksum             Enable (disable) line checksumming
      --(no-)compat-libtool       Enable (disable) libtool compatibility mode
      --gcov-tool TOOL            Specify gcov tool location
      --filter TYPE               Apply FILTERS to input data (see man page
                                  for full list of filters and their effects)
      --demangle-cpp              Demangle C++ function names
      --no-recursion              Exclude subdirectories from processing
      --to-package FILENAME       Store unprocessed coverage data in FILENAME
      --from-package FILENAME     Capture from unprocessed data in FILENAME
      --no-markers                Ignore exclusion markers in source code
      --derive-func-data          Generate function data from line data
      --list-full-path            Print full path during a list operation
      --(no-)external             Include (ignore) data for external files
      --compat MODE=on|off|auto   Set compat MODE (libtool, hammer, split_crc)
      --include PATTERN           Include files matching PATTERN
      --exclude PATTERN           Exclude files matching PATTERN
      --substitute REGEXP         Change source file names according to REGEXP
      --erase-functions REGEXP    Exclude data for functions matching REGEXP
      --omit-lines REGEXP         Ignore data in lines matching REGEXP
      --forget-test-names         Merge data for all tests names
      --fail-under-lines MIN      Exit with a status of 1 if the total line
                                  coverage is less than MIN (summary option)
      --version-script SCRIPTNAME Call script to find revision control version
                                  ID of source file
      --resolve-script SCRIPTNAME Call script to find source file from path
  -j, --parallel [NUM]            Use parallel processing with at most NUM jobs
      --memory MB                 Use at most MB memory in parallel processing
      --profile [FILENAME]        Write performance statistics to FILENAME
                                  (default: OUTPUT_FILENAME.json)

For more information see the lcov man page.
END_OF_USAGE

}

#
# check_options()
#
# Check for valid combination of command line options. Die on error.
#

sub check_options()
{
    my $i = 0;

    # Count occurrence of mutually exclusive options
    $reset                  && $i++;
    $lcovutil::lcov_capture && $i++;
    $add_tracefile          && $i++;
    $lcovutil::lcov_extract && $i++;
    $lcovutil::lcov_remove  && $i++;
    $list                   && $i++;
    $opt_summary            && $i++;
    @intersect              && $i++;
    @difference             && $i++;

    if ($i == 0 ||
        $i > 1) {
        die("invalid command line:\n  $0 " .
                join(' ', @main::cmdArgs) .
                "\nNeed " . ($i > 1 ? 'only ' : '') .
                "one of options -z, -c, -a, -e, -r, -l, --intersect, --subtract, or --summary\n"
                . "Use $tool_name --help to get usage information\n");
    }

    if ($prune_testcases && !$add_tracefile) {
        lcovutil::ignorable_error($lcovutil::ERROR_USAGE,
            "--prune-tests has effect only when -a/--add-tracefile is specified"
        );
    }
}

#
# userspace_reset()
#
# Reset coverage data found in DIRECTORY by deleting all contained .da files.
#
# Die on error.
#

sub userspace_reset()
{
    my @file_list;

    foreach my $pattern (@ARGV) {
        my @dirs;
        if (-d $pattern) {
            push(@dirs, $pattern);
        } else {
            $pattern =~ s/([^\\]) /$1\\ /g          # explicitly escape spaces
                unless $^O =~ /Win/;
            @dirs = glob($pattern);
        }
        my $count = 0;
        foreach my $current_dir (@dirs) {
            if (!-d $current_dir) {
                lcovutil::ignorable_error($lcovutil::ERROR_USAGE,
                                          "$current_dir is not a directory");
                next;
            }
            ++$count;
            info("Deleting all .da files in $current_dir" .
                 ($no_recursion ? "\n" : " and subdirectories\n"));
            @file_list =
                `find "$current_dir" $maxdepth $follow -name \\*\\.da -type f -o -name \\*\\.gcda -type f 2>$lcovutil::devnull`;
            die("Error return code from 'find \"$current_dir\" ...': $!")
                if ($?);
            chomp(@file_list);
            foreach (@file_list) {
                unlink($_) or die("cannot remove file $_: $!\n");
            }
        }
        lcovutil::ignorable_error($ERROR_EMPTY,
                                "$pattern does not match any directory entries")
            if 0 == $count;
    }
}

#
# userspace_capture()
#
# Capture coverage data found in DIRECTORY and write it to a package (if
# TO_PACKAGE specified) or to OUTPUT_FILENAME or STDOUT.
#
# Die on error.
#

sub userspace_capture()
{
    my $dir;
    my $build;

    if (!defined($to_package)) {
        lcov_geninfo(@ARGV);
        return;
    }
    die("exactly one directory argument required with --to-package\n")
        if (scalar(@ARGV) != 1);
    $dir = $ARGV[0];
    if (defined($base_directory)) {
        $build = $base_directory;
    } else {
        $build = $dir;
    }
    create_package($to_package, $dir, $build);
}

#
# kernel_reset()
#
# Reset kernel coverage.
#
# Die on error.
#

sub kernel_reset()
{
    local *HANDLE;
    my $reset_file;

    info("Resetting kernel execution counters\n");
    if (-e "$gcov_dir/vmlinux") {
        $reset_file = "$gcov_dir/vmlinux";
    } elsif (-e "$gcov_dir/reset") {
        $reset_file = "$gcov_dir/reset";
    } else {
        die("no reset control found in $gcov_dir\n");
    }
    open(HANDLE, ">", $reset_file) or
        die("cannot write to $reset_file: $!\n");
    print(HANDLE "0");
    close(HANDLE);
}

#
# lcov_copy_single(from, to)
#
# Copy single regular file FROM to TO without checking its size. This is
# required to work with special files generated by the kernel
# seq_file-interface.
#
#
sub lcov_copy_single($$)
{
    my ($from, $to) = @_;
    my $content;
    local $/;
    local *HANDLE;

    open(HANDLE, "<", $from) or die("cannot read $from: $!\n");
    $content = <HANDLE>;
    close(HANDLE);
    open(HANDLE, ">", $to) or die("cannot write $to: $!\n");
    if (defined($content)) {
        print(HANDLE $content);
    }
    close(HANDLE);
}

#
# lcov_find(dir, function, data[, extension, ...)])
#
# Search DIR for files and directories whose name matches PATTERN and run
# FUNCTION for each match. If no pattern is specified, match all names.
#
# FUNCTION has the following prototype:
#   function(dir, relative_name, data)
#
# Where:
#   dir: the base directory for this search
#   relative_name: the name relative to the base directory of this entry
#   data: the DATA variable passed to lcov_find
#
sub lcov_find($$$;@)
{
    my ($dir, $fn, $data, @pattern) = @_;
    my $result;
    my $_fn = sub {
        my $filename = $File::Find::name;

        if (defined($result)) {
            return;
        }
        $filename = abs2rel($filename, $dir);
        foreach (@pattern) {
            if (($lcovutil::case_insensitive && $filename =~ /$_/i) ||
                (!$lcovutil::case_insensitive && $filename =~ /$_/)) {
                goto ok;
            }
        }
        return;
        ok:
        $result = &$fn($dir, $filename, $data);
    };
    if (scalar(@pattern) == 0) {
        @pattern = (".*");
    }
    find({wanted => $_fn, no_chdir => 1}, $dir);

    return $result;
}

#
# lcov_copy_fn(from, rel, to)
#
# Copy directories, files and links from/rel to to/rel.
#

sub lcov_copy_fn($$$)
{
    my ($from, $rel, $to) = @_;
    my $absfrom = canonpath(catfile($from, $rel));
    my $absto   = canonpath(catfile($to, $rel));

    if (-d) {
        if (!-d $absto) {
            mkpath($absto) or
                die("cannot create directory $absto\n");
            chmod(0700, $absto);
        }
    } elsif (-l) {
        # Copy symbolic link
        my $link = readlink($absfrom);

        if (!defined($link)) {
            die("cannot read link $absfrom: $!\n");
        }
        symlink($link, $absto) or
            die("cannot create link $absto: $!\n");
    } else {
        lcov_copy_single($absfrom, $absto);
        chmod(0600, $absto);
    }
    return undef;
}

#
# lcov_copy(from, to, subdirs)
#
# Copy all specified SUBDIRS and files from directory FROM to directory TO. For
# regular files, copy file contents without checking its size. This is required
# to work with seq_file-generated files.
#

sub lcov_copy($$;@)
{
    my ($from, $to, @subdirs) = @_;
    my @pattern;

    foreach (@subdirs) {
        push(@pattern, "^$_");
    }
    lcov_find($from, \&lcov_copy_fn, $to, @pattern);
}

#
# lcov_geninfo(directory)
#
# Call geninfo for the specified directory and with the parameters specified
# at the command line.
#

sub lcov_geninfo(@)
{
    my (@dir) = @_;
    my @param;

    # Capture data
    info("Capturing coverage data from " . join(" ", @dir) . "\n");
    @param = (File::Spec->catfile($tool_dir, 'geninfo'), @dir);
    # make things less confusing for user, by using the name they actually invoked
    push(@param, '--toolname', $lcovutil::tool_name);
    push(@param, '--call-from-lcov');
    if ($output_filename) {
        push(@param, "--output-filename", $output_filename);
    }
    if ($test_name) {
        push(@param, "--test-name", $test_name);
    }
    if ($follow) {
        push(@param, "--follow");
    }
    push(@param, '--msg-log', $lcovutil::message_filename)
        if $lcovutil::message_filename;
    if ($lcovutil::verbose != 0) {
        if ($lcovutil::verbose < 0) {
            for (my $i = $lcovutil::verbose; $i < 0; ++$i) {
                push(@param, '--quiet');
            }
        } else {
            for (my $i = 0; $i < $lcovutil::verbose; ++$i) {
                push(@param, '--verbose');
            }
        }
    }
    if (defined($verify_checksum)) {
        push(@param, $verify_checksum ? '--checksum' : '--no-checksum');
    }
    foreach my $s (@ReadCurrentSource::source_directories) {
        # a bit of a hack:  we pushed the --base-directory argument onto
        #  the source list - and we need to make sure that we only pass
        #  it to geninfo once.
        push(@param, "--source-directory", $s)
            unless (defined($base_directory) && $s eq $base_directory);
    }
    if (defined($compat_libtool) && $compat_libtool == 0) {
        push(@param, "--no-compat-libtool");
    } elsif ($compat_libtool) {
        push(@param, "--compat-libtool");
    }
    if (defined($lcovutil::stop_on_error) && $lcovutil::stop_on_error == 0) {
        push(@param, "--keep-going");
    }
    if (defined($lcovutil::preserve_intermediates) &&
        $lcovutil::preserve_intermediates) {
        push(@param, "--preserve");
    }
    push(@param, "--base-directory", $base_directory)
        if $base_directory;
    foreach (
             split($lcovutil::split_char,
                   join($lcovutil::split_char, @lcovutil::opt_ignore_errors))
    ) {
        # pass only the 'ignore' options that geninfo understands
        push(@param, "--ignore-errors", $_)
            if exists($lcovutil::lcovErrors{$_});
    }
    if ($no_recursion) {
        push(@param, "--no-recursion");
    }
    if ($initial) {
        push(@param, "--initial");
    }
    if ($captureAll) {
        push(@param, "--all");
    }
    if ($no_markers) {
        push(@param, "--no-markers");
    }
    if ($opt_derive_func_data) {
        push(@param, "--derive-func-data");
    }
    for (my $i = 0; $i < $lcovutil::debug; ++$i) {
        push(@param, "--debug");
    }
    if (defined($lcovutil::opt_no_external) && $lcovutil::opt_no_external == 0)
    {
        push(@param, "--external");
    } elsif (defined($lcovutil::opt_no_external) && $lcovutil::opt_no_external)
    {
        push(@param, "--no-external");
    }
    if (defined($opt_compat)) {
        push(@param, "--compat", $opt_compat);
    }

    if (defined($lcovutil::profile)) {
        push(@param, '--profile');
        push(@param, $lcovutil::profile)
            if ('' ne $lcovutil::profile);
    }
    if (defined($lcovutil::maxParallelism)) {
        push(@param, '--parallel', $lcovutil::maxParallelism);
    }
    # memory has not been multiplied by Mb yet - so just pass the integer value
    push(@param, '--memory', $lcovutil::maxMemory)
        if defined($lcovutil::maxMemory);
    # function coverage was enabled by default
    push(@param, '--no-function-coverage')
        if (!$lcovutil::func_coverage);
    push(@param, "--branch-coverage") if $lcovutil::br_coverage;
    push(@param, "--mcdc") if $lcovutil::mcdc_coverage;
    push(@param, '--fail-under-lines', $lcovutil::fail_under_lines)
        if defined($lcovutil::fail_under_lines);
    push(@param, '--tempdir', $lcovutil::tempdirname)
        if (defined($lcovutil::tempdirname));
    foreach my $listOpt (['--comment', \@lcovutil::comments],
                         ['--config-file', \@lcovutil::opt_config_files],
                         ['--rc', \@lcovutil::opt_rc],
                         ['--build-directory', \@lcovutil::build_directory],
                         ['--gcov-tool', \@gcov_tool],
                         ['--demangle-cpp', \@lcovutil::cpp_demangle],
                         ['--include', \@lcovutil::include_file_patterns],
                         ['--exclude', \@lcovutil::exclude_file_patterns],
                         ['--context-script', \@lcovutil::contextCallback],
                         ['--criteria-script',
                          \@CoverageCriteria::coverageCriteriaScript
                         ],
                         ['--version-script', \@lcovutil::extractVersionScript],
                         ['--resolve-script', \@lcovutil::resolveCallback],
                         ['--substitute', \@lcovutil::file_subst_patterns],
                         ['--history-script',
                          \@lcovutil::profileHistoryCallback
                         ],
                         ['--omit-lines', \@lcovutil::omit_line_patterns],
                         ['--erase-functions',
                          \@lcovutil::exclude_function_patterns
                         ],
                         ['--filter', \@lcovutil::opt_filter],
                         ['--large-file', \@large_files],
    ) {
        my ($opt, $l) = @$listOpt;
        foreach my $v (@$l) {
            push(@param, $opt, $v);
        }
    }

    # windows
    #  Kind of hacky to fork another script here.
    #  Probably better/cleaner to move the 'geninfo' functionality into
    #  a perl module - then use it here and in the geninfo script.
    #  Maybe someday.
    unshift(@param, $lcovutil::interp) if defined($lcovutil::interp);
    info("geninfo cmd: '" . join(' ', @param) . "'\n");
    system(@param) and exit($? >> 8);
}

#
# read_file(filename)
#
# Return the contents of the file defined by filename.
#

sub read_file($)
{
    my ($filename) = @_;
    my $content;
    local $\;
    local *HANDLE;

    open(HANDLE, "<", $filename) || return undef;
    $content = <HANDLE>;
    close(HANDLE);

    return $content;
}

#
# get_package(package_file)
#
# Unpack unprocessed coverage data files from package_file to a temporary
# directory and return directory name, build directory and gcov kernel version
# as found in package.
#

sub get_package($)
{
    my ($file) = @_;
    my $dir = create_temp_dir();
    my $gkv;
    my $build;
    my $cwd = getcwd();
    my $count;
    local *HANDLE;

    info("Reading package $file:\n");
    $file = abs_path($file);
    chdir($dir);
    open(HANDLE, "-|", "tar xvfz " . quotemeta($file) . " 2>$lcovutil::devnull")
        or
        die("could not process package $file: $!\n");
    $count = 0;
    while (<HANDLE>) {
        if (/\.da$/ || /\.gcda$/) {
            $count++;
        }
    }
    close(HANDLE);
    if ($count == 0) {
        die("no data file found in package $file\n");
    }
    info("  data directory .......: $dir\n");
    $build = read_file(File::Spec->catfile($dir, $pkg_build_file));
    if (defined($build)) {
        info("  build directory ......: $build\n");
    }
    $gkv = read_file(File::Spec->catfile($dir, $pkg_gkv_file));
    if (defined($gkv)) {
        $gkv = int($gkv);
        if ($gkv != $GKV_PROC && $gkv != $GKV_SYS) {
            die("unsupported gcov kernel version found ($gkv)\n");
        }
        info("  content type .........: kernel data\n");
        info("  gcov kernel version ..: %s\n", $GKV_NAME[$gkv]);
    } else {
        info("  content type .........: application data\n");
    }
    info("  data files ...........: $count\n");
    chdir($cwd);

    return ($dir, $build, $gkv);
}

#
# write_file(filename, $content)
#
# Create a file named filename and write the specified content to it.
#

sub write_file($$)
{
    my ($filename, $content) = @_;
    local *HANDLE;

    open(HANDLE, ">", $filename) || return 0;
    print(HANDLE $content);
    close(HANDLE) || return 0;

    return 1;
}

# count_package_data(filename)
#
# Count the number of coverage data files in the specified package file.
#

sub count_package_data($)
{
    my ($filename) = @_;
    local *HANDLE;
    my $count = 0;

    open(HANDLE, "-|", "tar tfz " . quotemeta($filename)) or return undef;
    while (<HANDLE>) {
        if (/\.da$/ || /\.gcda$/) {
            $count++;
        }
    }
    close(HANDLE);
    return $count;
}

#
# create_package(package_file, source_directory, build_directory[,
#                kernel_gcov_version])
#
# Store unprocessed coverage data files from source_directory to package_file.
#

sub create_package($$$;$)
{
    my ($file, $dir, $build, $gkv) = @_;
    my $cwd = getcwd();

    # Check for availability of tar tool first
    system("tar --help > $lcovutil::devnull") and
        die("tar command not available\n");

    # Print information about the package
    info("Creating package $file:\n");
    info("  data directory .......: $dir\n");

    # Handle build directory
    if (defined($build)) {
        info("  build directory ......: $build\n");
        write_file(File::Spec->catfile($dir, $pkg_build_file), $build) or
            die("could not write to $dir/$pkg_build_file\n");
    }

    # Handle gcov kernel version data
    if (defined($gkv)) {
        info("  content type .........: kernel data\n");
        info("  gcov kernel version ..: %s\n", $GKV_NAME[$gkv]);
        write_file(File::Spec->catfile($dir, $pkg_gkv_file), $gkv) or
            die("could not write to $dir/$pkg_gkv_file\n");
    } else {
        info("  content type .........: application data\n");
    }

    # Create package
    $file = abs_path($file);
    chdir($dir);
    system("tar", "cfz", $file, ".") and
        die("could not create package $file\n");
    chdir($cwd);

    # Remove temporary files
    unlink(File::Spec->catfile($dir, $pkg_build_file));
    unlink(File::Spec->catfile($dir, $pkg_gkv_file));

    # Show number of data files
    if ($lcovutil::verbose >= 0) {
        my $count = count_package_data($file);

        if (defined($count)) {
            info("  data files ...........: $count\n");
        }
    }
}

sub find_link_fn($$$)
{
    my ($from, $rel, $filename) = @_;
    my $absfile = catfile($from, $rel, $filename);

    if (-l $absfile) {
        return $absfile;
    }
    return undef;
}

#
# get_base(dir)
#
# Return (BASE, OBJ), where
#  - BASE: is the path to the kernel base directory relative to dir
#  - OBJ: is the absolute path to the kernel build directory
#

sub get_base($)
{
    my ($dir) = @_;
    my $marker = "kernel/gcov/base.gcno";
    my $markerfile;
    my $sys;
    my $obj;
    my $link;

    $markerfile = lcov_find($dir, \&find_link_fn, $marker);
    if (!defined($markerfile)) {
        return (undef, undef);
    }

    # sys base is parent of parent of markerfile.
    $sys = abs2rel(dirname(dirname(dirname($markerfile))), $dir);

    # obj base is parent of parent of markerfile link target.
    $link = readlink($markerfile);
    if (!defined($link)) {
        die("could not read $markerfile\n");
    }
    $obj = dirname(dirname(dirname($link)));

    return ($sys, $obj);
}

#
# apply_base_dir(data_dir, base_dir, build_dir, @directories)
#
# Make entries in @directories relative to data_dir.
#

sub apply_base_dir($$$@)
{
    my ($data, $base, $build, @dirs) = @_;
    my $dir;
    my @result;

    foreach $dir (@dirs) {
        # Is directory path relative to data directory?
        if (-d catdir($data, $dir)) {
            push(@result, $dir);
            next;
        }
        # Relative to the auto-detected base-directory?
        if (defined($base)) {
            if (-d catdir($data, $base, $dir)) {
                push(@result, catdir($base, $dir));
                next;
            }
        }
        # Relative to the specified base-directory?
        if (defined($base_directory)) {
            if (file_name_is_absolute($base_directory)) {
                $base = abs2rel($base_directory, rootdir());
            } else {
                $base = $base_directory;
            }
            if (-d catdir($data, $base, $dir)) {
                push(@result, catdir($base, $dir));
                next;
            }
        }
        # Relative to the build directory?
        if (defined($build)) {
            if (file_name_is_absolute($build)) {
                $base = abs2rel($build, rootdir());
            } else {
                $base = $build;
            }
            if (-d catdir($data, $base, $dir)) {
                push(@result, catdir($base, $dir));
                next;
            }
        }
        die("subdirectory $dir not found\n" .
            "Please use -b to specify the correct directory\n");
    }
    return @result;
}

#
# copy_gcov_dir(dir, [@subdirectories])
#
# Create a temporary directory and copy all or, if specified, only some
# subdirectories from dir to that directory. Return the name of the temporary
# directory.
#

sub copy_gcov_dir($;@)
{
    my ($data, @dirs) = @_;
    my $tempdir = create_temp_dir();

    info("Copying data to temporary directory $tempdir\n");
    lcov_copy($data, $tempdir, @dirs);

    return $tempdir;
}

#
# kernel_capture_initial
#
# Capture initial kernel coverage data, i.e. create a coverage data file from
# static graph files which contains zero coverage data for all instrumented
# lines.
#

sub kernel_capture_initial()
{
    my $build;
    my $source;
    my @params;

    if (defined($base_directory)) {
        $build  = $base_directory;
        $source = "specified";
    } else {
        (undef, $build) = get_base($gcov_dir);
        if (!defined($build)) {
            die("could not auto-detect build directory.\n" .
                "Please use -b to specify the build directory\n");
        }
        $source = "auto-detected";
    }
    info("Using $build as kernel build directory ($source)\n");
    # Build directory needs to be passed to geninfo
    $base_directory = $build;
    if ($kernel_directory) {
        foreach my $dir (@ARGV) {
            push(@params, File::Spec->catdir($build, $dir));
        }
    } else {
        push(@params, $build);
    }
    lcov_geninfo(@params);
}

#
# kernel_capture_from_dir(directory, gcov_kernel_version, build)
#
# Perform the actual kernel coverage capturing from the specified directory
# assuming that the data was copied from the specified gcov kernel version.
#

sub kernel_capture_from_dir($$$)
{
    my ($dir, $gkv, $build) = @_;

    # Create package or coverage file
    if (defined($to_package)) {
        create_package($to_package, $dir, $build, $gkv);
    } else {
        # Build directory needs to be passed to geninfo
        $base_directory = $build;
        lcov_geninfo($dir);
    }
}

#
# adjust_kernel_dir(dir, build)
#
# Adjust directories specified with -k so that they point to the directory
# relative to DIR. Return the build directory if specified or the auto-
# detected build-directory.
#

sub adjust_kernel_dir($$)
{
    my ($dir, $build)           = @_;
    my ($sys_base, $build_auto) = get_base($dir);

    if (!defined($build)) {
        $build = $build_auto;
    }
    if (!defined($build)) {
        die("could not auto-detect build directory.\n" .
            "Please use -b to specify the build directory\n");
    }
    # Make kernel dirs (from @ARGV) relative to sysfs base
    if ($kernel_directory) {
        @ARGV = apply_base_dir($dir, $sys_base, $build, @ARGV);
    }
    return $build;
}

sub kernel_capture()
{
    my $data_dir;
    my $build = $base_directory;

    if ($gcov_gkv == $GKV_SYS) {
        $build = adjust_kernel_dir($gcov_dir, $build);
    }
    $data_dir = copy_gcov_dir($gcov_dir, $kernel_directory ? @ARGV : ());
    kernel_capture_from_dir($data_dir, $gcov_gkv, $build);
}

#
# link_data_cb(datadir, rel, graphdir)
#
# Create symbolic link in GRAPDIR/REL pointing to DATADIR/REL.
#

sub link_data_cb($$$)
{
    my ($datadir, $rel, $graphdir) = @_;
    my $absfrom = catfile($datadir, $rel);
    my $absto   = catfile($graphdir, $rel);
    my $base;

    if (-e $absto) {
        die("could not create symlink at $absto: " . "File already exists!\n");
    }
    if (-l $absto) {
        # Broken link - possibly from an interrupted earlier run
        unlink($absto);
    }

    # Check for graph file
    $base = $absto;
    $base =~ s/\.(gcda|da)$//;
    if (!-e $base . ".gcno") {
        die("No graph file found for $absfrom in " . dirname($base) . "!\n");
    }

    symlink($absfrom, $absto) or
        die("could not create symlink at $absto: $!\n");
}

#
# unlink_data_cb(datadir, rel, graphdir)
#
# Remove symbolic link from GRAPHDIR/REL to DATADIR/REL.
#

sub unlink_data_cb($$$)
{
    my ($datadir, $rel, $graphdir) = @_;
    my $absfrom = catfile($datadir, $rel);
    my $absto   = catfile($graphdir, $rel);
    my $target;

    return if (!-l $absto);
    $target = readlink($absto);
    return if (!defined($target) || $target ne $absfrom);

    unlink($absto) or
        warn("could not remove symlink $absto: $!\n");
}

#
# link_data(datadir, graphdir, create)
#
# If CREATE is non-zero, create symbolic links in GRAPHDIR for data files
# found in DATADIR. Otherwise remove link in GRAPHDIR.
#

sub link_data($$$)
{
    my ($datadir, $graphdir, $create) = @_;

    $datadir  = abs_path($datadir);
    $graphdir = abs_path($graphdir);
    if ($create) {
        lcov_find($datadir, \&link_data_cb, $graphdir, '\.gcda$', '\.da$');
    } else {
        lcov_find($datadir, \&unlink_data_cb, $graphdir, '\.gcda$', '\.da$');
    }
}

#
# find_graph_cb(datadir, rel, count_ref)
#
# Count number of files found.
#

sub find_graph_cb($$$)
{
    my ($dir, $rel, $count_ref) = @_;

    ($$count_ref)++;
}

#
# find_graph(dir)
#
# Search DIR for a graph file. Return non-zero if one was found, zero otherwise.
#

sub find_graph($)
{
    my ($dir) = @_;
    my $count = 0;

    lcov_find($dir, \&find_graph_cb, \$count, '\.gcno$');

    return $count > 0 ? 1 : 0;
}

#
# package_capture()
#
# Capture coverage data from a package of unprocessed coverage data files
# as generated by lcov --to-package.
#

sub package_capture()
{
    my $dir;
    my $build;
    my $gkv;

    ($dir, $build, $gkv) = get_package($from_package);

    # Check for build directory
    if (defined($base_directory)) {
        if (defined($build)) {
            info("Using build directory specified by -b.\n");
        }
        $build = $base_directory;
    }

    # Do the actual capture
    if (defined($gkv)) {
        if ($gkv == $GKV_SYS) {
            $build = adjust_kernel_dir($dir, $build);
        }
        if ($kernel_directory) {
            $dir = copy_gcov_dir($dir, @ARGV);
        }
        kernel_capture_from_dir($dir, $gkv, $build);
    } else {
        # Build directory needs to be passed to geninfo
        $base_directory = $build;
        if (find_graph($dir)) {
            # Package contains graph files - collect from there
            lcov_geninfo($dir);
        } else {
            # No graph files found, link data files next to
            # graph files
            link_data($dir, $base_directory, 1);
            lcov_geninfo($base_directory);
            link_data($dir, $base_directory, 0);
        }
    }
}

#
# info(printf_parameter)
#
# Use printf to write PRINTF_PARAMETER to stdout only when the $quiet flag
# is not set.
#

sub my_info(@)
{
    # Print info string
    if (!$data_stdout) {
        printf(@_);
    } else {
        # Don't interfere with the .info output to STDOUT
        printf(STDERR @_);
    }
}

# emit()
#  write output to file or stdout - possibly with info message

sub emit
{
    my ($trace, $info_msg) = @_;
    my $to = $data_stdout ? '-' : $output_filename;
    if (!$data_stdout) {
        info($info_msg)
            if $info_msg;
        info("Writing data to $output_filename\n");
    }
    $trace->add_comments(@lcovutil::comments);
    $trace->write_info_file($to, $lcovutil::verify_checksum);
}

#
#
# add_traces()
#

sub add_traces()
{
    info("Combining tracefiles.\n");
    my @merge = AggregateTraces::find_from_glob(@ARGV);
    info(".. found " . scalar(@merge) . " files to aggregate.\n");

    my ($total_trace, $effective) =
        AggregateTraces::merge(ReadCurrentSource->new(), @merge);

    if ($AggregateTraces::function_mapping) {
        return;
    } elsif ($prune_testcases) {
        return ($effective, \@merge);
    } else {
        # write the result
        emit($total_trace);
        return $total_trace;
    }
}

#
#
# merge_traces()
#

sub merge_traces($$)
{
    my ($list, $op) = @_;
    info(($op == TraceInfo::INTERSECT ? 'Intersect' : 'Subtract') .
         " tracefiles.\n");

    my @data = AggregateTraces::find_from_glob(@ARGV);
    info('.. found: ' .
         scalar(@data) . " 'base' trace file" .
         (1 == scalar(@data) ? '' : 's') . ".\n");
    die("must specify at least one 'base' tracefile")
        unless @data;
    my @merge = AggregateTraces::find_from_glob(@$list);
    info('          ' .
         scalar(@merge) .
         ' file' . (1 == scalar(@merge) ? '' : 's') . ' to ' .
         ($op == TraceInfo::INTERSECT ? 'intersect' : 'subtract') . ".\n");

    my $srcReader = ReadCurrentSource->new();
    my ($base)    = AggregateTraces::merge($srcReader, @data);
    my ($merge)   = AggregateTraces::merge($srcReader, @merge);

    $base->merge_tracefile($merge, $op);
    # write the result
    emit($base);
    return $base;
}

sub remove_file_patterns($)
{
    my $filename = shift;

    my $readSourceFile = ReadCurrentSource->new();
    my $now            = Time::HiRes::gettimeofday();
    my $data =
        TraceFile->load($filename, $readSourceFile, $lcovutil::verify_checksum);
    my $then = Time::HiRes::gettimeofday();
    $lcovutil::profileData{parse} = $then - $now;

    # Write extracted data
    my $removed = scalar(keys(%lcovutil::excluded_files));
    emit($data, "Removed $removed files\n");
    return $data;
}

# get_prefix(max_width, max_percentage_too_long, path_list)
#
# Return a path prefix that satisfies the following requirements:
# - is shared by more paths in path_list than any other prefix
# - the percentage of paths which would exceed the given max_width length
#   after applying the prefix does not exceed max_percentage_too_long
#
# If multiple prefixes satisfy all requirements, the longest prefix is
# returned. Return an empty string if no prefix could be found.

sub get_prefix($$@)
{
    my ($max_width, $max_long, @path_list) = @_;
    my $path;
    my $ENTRY_NUM  = 0;
    my $ENTRY_LONG = 1;
    my %prefix;

    # Build prefix hash
    foreach $path (@path_list) {
        my ($v, $d, $f) = splitpath($path);
        my @dirs  = splitdir($d);
        my $p_len = length($path);

        # Remove trailing '/'
        pop(@dirs)
            if (0 != scalar(@dirs) && $dirs[scalar(@dirs) - 1] eq '');
        for (my $i = 0; $i < scalar(@dirs); $i++) {
            my $subpath = catpath($v, catdir(@dirs[0 .. $i]), '');
            my $entry   = $prefix{$subpath};

            $entry = [0, 0] if (!defined($entry));
            $entry->[$ENTRY_NUM]++;
            if (($p_len - length($subpath) - 1) > $max_width) {
                $entry->[$ENTRY_LONG]++;
            }
            $prefix{$subpath} = $entry;
        }
    }
    # Find suitable prefix (sort descending by two keys: 1. number of
    # entries covered by a prefix, 2. length of prefix)
    foreach $path (sort {
                       ($prefix{$a}->[$ENTRY_NUM] == $prefix{$b}->[$ENTRY_NUM])
                           ?
                           length($b) <=> length($a) :
                           $prefix{$b}->[$ENTRY_NUM]
                           <=> $prefix{$a}->[$ENTRY_NUM]
                   }
                   keys(%prefix)
    ) {
        my ($num, $long) = @{$prefix{$path}};

        # Check for additional requirement: number of filenames
        # that would be too long may not exceed a certain percentage
        if ($long <= $num * $max_long / 100) {
            return $path;
        }
    }

    return "";
}

#
# shorten_filename(filename, width)
#
# Truncate filename if it is longer than width characters.
#

sub shorten_filename($$)
{
    my ($filename, $width) = @_;
    my $l = length($filename);
    my $s;
    my $e;

    return $filename if ($l <= $width);
    $e = int(($width - 3) / 2);
    $s = $width - 3 - $e;

    return substr($filename, 0, $s) . '...' . substr($filename, $l - $e);
}

sub shorten_number($$)
{
    my ($number, $width) = @_;
    my $result = sprintf("%*d", $width, $number);

    return $result if (length($result) <= $width);
    $number = $number / 1000;
    $result = sprintf("%*dk", $width - 1, $number);
    return $result if (length($result) <= $width);
    $number = $number / 1000;
    $result = sprintf("%*dM", $width - 1, $number);
    return (length($result) <= $width) ? $result : '#';
}

sub shorten_rate($$$)
{
    my ($hit, $found, $width) = @_;
    my $result = rate($hit, $found, "%", 1, $width);

    return $result if (length($result) <= $width);
    $result = rate($hit, $found, "%", 0, $width);
    return (length($result) <= $width) ? $result : "#";
}

#
# list()
#

sub list()
{
    my $readSourceFile = ReadCurrentSource->new();
    my $data;
    # Multiple tracefiles: merge them before listing.
    my @files = AggregateTraces::find_from_glob(@ARGV);
    ($data) = AggregateTraces::merge($readSourceFile, @files);

    my $strlen = length("Filename");
    my $lastpath;
    my $F_LN_NUM      = 0;
    my $F_LN_RATE     = 1;
    my $F_FN_NUM      = 2;
    my $F_FN_RATE     = 3;
    my $F_BR_NUM      = 4;
    my $F_BR_RATE     = 5;
    my $F_MCDC_NUM    = 6;
    my $F_MCDC_RATE   = 7;
    my @fwidth_narrow = (5, 5, 3, 5, 4, 5, 4, 5);
    my @fwidth_wide   = (6, 5, 5, 5, 6, 5, 6, 5);
    my @fwidth        = @fwidth_wide;
    my $max_width     = $opt_list_width;
    my $max_long      = $opt_list_truncate_max;

    # Calculate total width of narrow fields
    my $fwidth_narrow_length = 0;
    foreach my $w (@fwidth_narrow) {
        $fwidth_narrow_length += $w + 1;
    }
    # Calculate total width of wide fields
    my $fwidth_wide_length = 0;
    foreach my $w (@fwidth_wide) {
        $fwidth_wide_length += $w + 1;
    }
    # Get common file path prefix
    my $prefix = get_prefix($max_width - $fwidth_narrow_length,
                            $max_long, $data->files());
    my $root_prefix = ($prefix eq rootdir());
    my $got_prefix  = (length($prefix) > 0);
    $prefix =~ s/$lcovutil::dirseparator$//;
    # Get longest filename length
    foreach my $filename ($data->files()) {
        if (!$opt_list_full_path) {
            if (!$got_prefix ||
                !$root_prefix && !(($lcovutil::case_insensitive &&
                                    $filename =~ s/^\Q$prefix\/\E//i) ||
                                   (!$lcovutil::case_insensitive &&
                                    $filename =~ s/^\Q$prefix\/\E//))
            ) {
                my ($v, $d, $f) = splitpath($filename);

                $filename = $f;
            }
        }
        # Determine maximum length of entries
        if (length($filename) > $strlen) {
            $strlen = length($filename);
        }
    }
    if (!$opt_list_full_path) {

        my $w = $fwidth_wide_length;
        # Check if all columns fit into max_width characters
        if ($strlen + $fwidth_wide_length > $max_width) {
            # Use narrow fields
            @fwidth = @fwidth_narrow;
            $w      = $fwidth_narrow_length;
            if (($strlen + $fwidth_narrow_length) > $max_width) {
                # Truncate filenames at max width
                $strlen = $max_width - $fwidth_narrow_length;
            }
        }
        # Add some blanks between filename and fields if possible
        my $blanks = int($strlen * 0.5);
        $blanks = 4 if ($blanks < 4);
        $blanks = 8 if ($blanks > 8);
        if (($strlen + $w + $blanks) < $max_width) {
            $strlen += $blanks;
        } else {
            $strlen = $max_width - $w;
        }
    }
    # Filename
    my $w        = $strlen;
    my $format   = "%-${w}s|";
    my $heading1 = sprintf("%*s|", $w, "");
    my $heading2 = sprintf("%-*s|", $w, "Filename");
    my $barlen   = $w + 1;

    # name, total_found, total_hit, total_column_width, rate_column_width
    my @types = (['Lines', \&TraceInfo::sum, 0, 0, $F_LN_NUM, $F_LN_RATE],
                 [$lcovutil::func_coverage ? 'Functions' : undef,
                  \&TraceInfo::func, 0, 0, $F_FN_NUM, $F_FN_RATE
                 ],
                 [$lcovutil::br_coverage ? 'Branches' : undef,
                  \&TraceInfo::sumbr, 0, 0, $F_BR_NUM, $F_BR_RATE
                 ],
                 [$lcovutil::mcdc_coverage ? 'MC/DC' : undef,
                  \&TraceInfo::mcdc, 0, 0, $F_MCDC_NUM, $F_MCDC_RATE
                 ],);

    my $sep = '';
    foreach my $d (@types) {
        my ($type, $cb, $found, $hit, $n, $r) = @$d;
        next unless $type;
        $w = $fwidth[$r];
        $format   .= "$sep%${w}s ";
        $heading1 .= sprintf("$sep%-*s ", $w + $fwidth[$n], $type);
        $heading2 .= sprintf("$sep%-*s ", $w, "Rate");
        $barlen += $w + 1;
        # Number of coverpoints
        $w = $fwidth[$n];
        $format   .= "%${w}s";
        $heading2 .= sprintf("%*s", $w, "Num");
        $barlen += $w + 1;
        $sep = '|';
    }
    --$barlen;    # no separator for last column
                  # Line end
    $format   .= "\n";
    $heading1 .= "\n";
    $heading2 .= "\n";

    # Print heading
    print($heading1);
    print($heading2);
    print(("=" x $barlen) . "\n");

    # Print per file information
    foreach my $filename (sort($data->files())) {
        my $entry          = $data->data($filename);
        my $print_filename = $entry->filename();
        if (!$opt_list_full_path) {
            my $p;

            $print_filename = $filename;
            if (!$got_prefix ||
                !$root_prefix && !(($lcovutil::case_insensitive &&
                                    $print_filename =~ s/^\Q$prefix\/\E//i) ||
                                   (!$lcovutil::case_insensitive &&
                                    $print_filename =~ s/^\Q$prefix\/\E//))
            ) {
                my ($v, $d, $f) = splitpath($filename);

                $p = catpath($v, $d, "");
                $p =~ s/$lcovutil::dirseparator$//;
                $print_filename = $f;
            } else {
                $p = $prefix;
            }

            if (!defined($lastpath) || $lastpath ne $p) {
                print("\n") if (defined($lastpath));
                $lastpath = $p;
                print("[$lastpath/]\n") if (!$root_prefix);
            }
            $print_filename = shorten_filename($print_filename, $strlen);
        }
        my @file_data;
        push(@file_data, $print_filename);
        foreach my $d (@types) {
            my ($type, $cb, $total_found, $total_hit, $n, $r) = @$d;
            next unless defined($type);
            my $data = &{$cb}($entry);

            my ($found, $hit) = $data->get_found_and_hit();
            # add to totals
            $d->[2] += $found, $d->[3] += $hit;

            push(@file_data, shorten_rate($hit, $found, $fwidth[$r]));
            push(@file_data, shorten_number($found, $fwidth[$n]));
        }
        # Print assembled line
        printf($format, @file_data);
    }

    # Print separator
    print(("=" x $barlen) . "\n");

    # Assemble line parameters
    my @footer;
    push(@footer, sprintf("%*s", $strlen, "Total:"));
    foreach my $d (@types) {
        my ($type, $cb, $total_found, $total_hit, $n, $r) = @$d;
        next unless defined($type);

        push(@footer, shorten_rate($total_hit, $total_found, $fwidth[$r]));
        push(@footer, shorten_number($total_found, $fwidth[$n]));
    }
    # Print assembled line
    printf($format, @footer);
}

#
#
# summary()
#

sub summary()
{
    my @merge = AggregateTraces::find_from_glob(@ARGV);
    info(1, "Summarize " . scalar(@merge) . " files...\n");

    my ($total, $effective) =
        AggregateTraces::merge(ReadCurrentSource->new(), @merge);
    return $total;
}

sub setup_gkv_sys()
{
    system_no_output(3, "mount", "-t", "debugfs", "nodev", "/sys/kernel/debug");
}

sub setup_gkv_proc()
{
    if (system_no_output(3, "modprobe", "gcov_proc")) {
        system_no_output(3, "modprobe", "gcov_prof");
    }
}

sub check_gkv_sys($)
{
    my ($dir) = @_;

    if (-e "$dir/reset") {
        return 1;
    }
    return 0;
}

sub check_gkv_proc($)
{
    my ($dir) = @_;

    if (-e "$dir/vmlinux") {
        return 1;
    }
    return 0;
}

sub setup_gkv()
{
    my $dir;
    my $sys_dir  = "/sys/kernel/debug/gcov";
    my $proc_dir = "/proc/gcov";
    my @todo;

    if (!defined($gcov_dir)) {
        info("Auto-detecting gcov kernel support.\n");
        @todo = ("cs", "cp", "ss", "cs", "sp", "cp");
    } elsif ($gcov_dir =~ /proc/) {
        info("Checking gcov kernel support at $gcov_dir (user-specified).\n");
        @todo = ("cp", "sp", "cp", "cs", "ss", "cs");
    } else {
        info("Checking gcov kernel support at $gcov_dir (user-specified).\n");
        @todo = ("cs", "ss", "cs", "cp", "sp", "cp",);
    }
    foreach (@todo) {
        if ($_ eq "cs") {
            # Check /sys
            $dir = defined($gcov_dir) ? $gcov_dir : $sys_dir;
            if (check_gkv_sys($dir)) {
                info("Found " .
                     $GKV_NAME[$GKV_SYS] . " gcov kernel support at $dir\n");
                return ($GKV_SYS, $dir);
            }
        } elsif ($_ eq "cp") {
            # Check /proc
            $dir = defined($gcov_dir) ? $gcov_dir : $proc_dir;
            if (check_gkv_proc($dir)) {
                info("Found " . $GKV_NAME[$GKV_PROC] .
                     " gcov kernel support at $dir\n");
                return ($GKV_PROC, $dir);
            }
        } elsif ($_ eq "ss") {
            # Setup /sys
            setup_gkv_sys();
        } elsif ($_ eq "sp") {
            # Setup /proc
            setup_gkv_proc();
        }
    }
    if (defined($gcov_dir)) {
        die("could not find gcov kernel data at $gcov_dir\n");
    } else {
        die("no gcov kernel data found\n");
    }
}
