+# FUNCTIONS
+
+sub error_flags {
+ my ($message, $missing_flags_ref, $flag_renames_ref, $line) = @_;
+
+ # Rename flags if requested.
+ my @missing_flags = map {
+ (exists $flag_renames_ref->{$_})
+ ? $flag_renames_ref->{$_}
+ : $_
+ } @{$missing_flags_ref};
+
+ my $flags = join ' ', @missing_flags;
+ printf "%s (%s)%s %s",
+ error_color($message, 'red'), $flags, error_color(':', 'yellow'),
+ $line;
+}
+sub error_non_verbose_build {
+ my ($line) = @_;
+
+ printf "%s%s %s",
+ error_color('NONVERBOSE BUILD', 'red'),
+ error_color(':', 'yellow'),
+ $line;
+}
+sub error_color {
+ my ($message, $color) = @_;
+
+ # Use colors when writing to a terminal.
+ if (-t STDOUT) {
+ return Term::ANSIColor::colored($message, $color);
+ } else {
+ return $message;
+ }
+}
+
+sub any_flags_used {
+ my ($line, @flags) = @_;
+
+ foreach my $flag (@flags) {
+ return 1 if $line =~ /\s$flag(?:\s|\\|$)/;
+ }
+
+ return 0;
+}
+sub all_flags_used {
+ my ($line, $missing_flags_ref, @flags) = @_;
+
+ my @missing_flags = ();
+ foreach my $flag (@flags) {
+ if ($line !~ /\s$flag(?:\s|\\|$)/) {
+ push @missing_flags, $flag;
+ }
+ }
+
+ if (scalar @missing_flags == 0) {
+ return 1;
+ }
+
+ @{$missing_flags_ref} = @missing_flags;
+ return 0;
+}
+
+# Modifies $missing_flags_ref array.
+sub pic_pie_conflict {
+ my ($line, $pie, $missing_flags_ref, @flags_pie) = @_;
+
+ return 0 if not $pie;
+ return 0 if not any_flags_used($line, ('-fPIC', '-fpic'));
+
+ my %flags = map { $_ => 1 } @flags_pie;
+
+ # Remove all PIE flags from @missing_flags as they are not required with
+ # -fPIC.
+ my @result = grep {
+ not exists $flags{$_}
+ } @{$missing_flags_ref};
+ @{$missing_flags_ref} = @result;
+
+ # We got a conflict when no flags are left, thus only PIE flags were
+ # missing. If other flags were missing abort because the conflict is not
+ # the problem.
+ return scalar @result == 0;
+}
+
+sub is_non_verbose_build {
+ my ($line, $next_line, $cc_regex, $skip_ref) = @_;
+
+ my $cmake_non_verbose = qr/^\s*\[[\d ]+%\] Building (?:C|CXX) object (.+?)$/;
+ if (not ($line =~ /^checking if you want to see long compiling messages\.\.\. no/
+ or $line =~ /^\s*(?:CC|CCLD)\s+/
+ or $line =~ /^\s*(?:C|c)ompiling\s+/
+ or $line =~ /$cmake_non_verbose/)) {
+ return 0;
+ }
+
+ # On the first pass we only check if this line is verbose or not.
+ return 1 if not defined $next_line;
+
+ # Second pass, we have access to the next line.
+ ${$skip_ref} = 0;
+
+ # CMake prints the non-verbose messages also when building verbose. If a
+ # compiler and the file name occurs in the next line, treat it as verbose
+ # build.
+ if ($line =~ /$cmake_non_verbose/) {
+ # Get filename, we can't use the complete path as only parts of it are
+ # used in the real compiler command ...
+ $1 =~ m{/([a-zA-Z0-9._-]+)$};
+ my $file = $1;
+
+ if ($next_line =~ /\Q$file\E/ and $next_line =~ /$cc_regex/) {
+ # We still have to skip the current line as it doesn't contain any
+ # compiler commands.
+ ${$skip_ref} = 1;
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+
+# CONSTANTS/VARIABLES
+
+# Regex to catch compiler commands.
+my $cc_regex = qr/(?:(?<!\.)cc|(?:x86_64-linux-gnu-)?gcc|g\+\+|c\+\+)/;
+# Regex to catch (GCC) compiler warnings.
+my $warning_regex = qr/^(.+?):([0-9]+):[0-9]+: warning: (.+?) \[(.+?)\]$/;
+
+# Expected hardening flags. All flags are used as regexps.
+my @cflags = (
+ '-g',
+ '-O2',
+ '-fstack-protector',
+ '--param=ssp-buffer-size=4',
+ '-Wformat',
+ '-Wformat-security',
+ '-Werror=format-security',
+);
+my @cflags_pie = (
+ '-fPIE',
+);
+my @cppflags = (
+ '-D_FORTIFY_SOURCE=2',
+);
+my @ldflags = (
+ '-Wl,(-z,)?relro',
+);
+my @ldflags_pie = (
+ '-fPIE',
+ '-pie',
+);
+my @ldflags_bindnow = (
+ '-Wl,(-z,)?now',
+);
+# All (hardening) flags.
+my @flags = (@cflags, @cflags_pie,
+ @cppflags,
+ @ldflags, @ldflags_pie, @ldflags_bindnow);
+# Renaming rules for the output so the regex parts are not visible.
+my %flag_renames = (
+ '-Wl,(-z,)?relro' => '-Wl,-z,relro',
+ '-Wl,(-z,)?now' => '-Wl,-z,now',
+);
+
+
+# MAIN
+
+# Additional hardening options.
+my $pie = 0;
+my $bindnow = 0;
+