# Build log hardening check, checks build logs for missing hardening flags.
-# Copyright (C) 2012-2018 Simon Ruderich
+# Copyright (C) 2012-2024 Simon Ruderich
#
# 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
use Getopt::Long ();
use Text::ParseWords ();
-our $VERSION = '0.08';
+our $VERSION = '0.14';
# CONSTANTS/VARIABLES
my $cc_regex_normal = qr/
\b$cc_regex(?:\s|\\)
/x;
+my $rustc_regex = qr/
+ \brustc\b
+ /x;
# Regex to catch (GCC) compiler warnings.
my $warning_regex = qr/^(.+?):(\d+):\d+: warning: (.+?) \[(.+?)\]$/;
# Regex to catch libtool commands and not lines which show commands executed
# by libtool (e.g. libtool: link: ...).
-my $libtool_regex = qr/\blibtool\s.*--mode=/;
+my $libtool_regex = qr/\blibtool["']?\s.*--mode=/;
my $libtool_link_regex = qr/\blibtool: link: /;
# List of source file extensions which require preprocessing.
# Expected (hardening) flags. All flags are used as regexps (and compiled to
# real regexps below for better execution speed).
my @def_cflags = (
- '-g',
+ '-g3?',
'-O(?:2|3)', # keep at index 1, search for @def_cflags_debug to change it
);
my @def_cflags_debug = (
# fortify needs at least -O1, but -O2 is recommended anyway
);
my @def_cflags_stack = (
- '-fstack-protector',
+ '-fstack-protector', # keep first, used by cflags_stack_broken()
'--param[= ]ssp-buffer-size=4',
);
my @def_cflags_stack_strong = (
- '-fstack-protector-strong',
+ '-fstack-protector-strong', # keep first, used by cflags_stack_broken()
+);
+my @def_cflags_stack_bad = (
+ # Blacklist all stack protector options for simplicity.
+ '-fno-stack-protector',
+ '-fno-stack-protector-all',
+ '-fno-stack-protector-strong',
+);
+my @def_cflags_stack_clash = (
+ '-fstack-clash-protection',
);
my @def_cflags_pie = (
'-fPIE',
);
+my @def_cflags_branch_amd64 = (
+ '-fcf-protection',
+);
+my @def_cflags_branch_arm64 = (
+ '-mbranch-protection=standard',
+);
my @def_cxxflags = (
@def_cflags,
);
# @def_cxxflags_* is the same as @def_cflags_*.
my @def_cppflags = ();
my @def_cppflags_fortify = (
- '-D_FORTIFY_SOURCE=2', # must be first, see cppflags_fortify_broken()
+ '-D_FORTIFY_SOURCE=[23]', # must be first, see cppflags_fortify_broken()
# If you add another flag fix hack below (search for "Hack to fix") and
# $def_cppflags_fortify[0].
);
\@def_cflags_fortify,
\@def_cflags_stack,
\@def_cflags_stack_strong,
+ \@def_cflags_stack_bad,
+ \@def_cflags_stack_clash,
\@def_cflags_pie,
+ \@def_cflags_branch_amd64,
+ \@def_cflags_branch_arm64,
\@def_cxxflags,
\@def_cppflags,
\@def_cppflags_fortify,
# Renaming rules for the output so the regex parts are not visible. Also
# stores string values of flag regexps above, see compile_flag_regexp().
my %flag_renames = (
+ '-g3?' => '-g',
'-O(?:2|3)' => '-O2',
'-Wformat(?:=2)?' => '-Wformat',
'--param[= ]ssp-buffer-size=4' => '--param=ssp-buffer-size=4',
+ '-D_FORTIFY_SOURCE=[23]' => '-D_FORTIFY_SOURCE=2',
'-Wl,(?:-z,)?relro' => '-Wl,-z,relro',
'-Wl,(?:-z,)?now' => '-Wl,-z,now',
);
# FUNCTIONS
-# Only works for single-level arrays with no undef values. Thanks to perlfaq4.
-sub array_equal {
- my ($first_ref, $second_ref) = @_;
+sub split_line {
+ my ($line) = @_;
- return 0 if scalar @{$first_ref} != scalar @{$second_ref};
-
- my $length = scalar @{$first_ref};
- for (my $i = 0; $i < $length; $i++) {
- return 0 if $first_ref->[$i] ne $second_ref->[$i];
+ my @work = ($line);
+ foreach my $delim (';', '&&', '||') {
+ my @x;
+ foreach (@work) {
+ push @x, Text::ParseWords::parse_line(qr/\Q$delim\E/, 1, $_);
+ }
+ @work = @x;
}
- return 1;
+ return map {
+ # Ensure newline at the line end - necessary for
+ # correct parsing later.
+ $_ =~ s/\s+$//;
+ $_ .= "\n";
+ } @work;
}
sub error_flags {
@{$missing_flags_ref} = @missing_flags;
return 0;
}
+# Check if any of \@bad_flags occurs after $good_flag. Doesn't check if
+# $good_flag is present.
+sub flag_overwritten {
+ my ($line, $good_flag, $bad_flags) = @_;
-sub cppflags_fortify_broken {
- my ($line, $missing_flags) = @_;
-
- if (not any_flags_used($line, @def_cppflags_fortify_bad)) {
+ if (not any_flags_used($line, @{$bad_flags})) {
return 0;
}
- # $def_cppflags_fortify[0] must be -D_FORTIFY_SOURCE=2!
- my $fortify_source = $def_cppflags_fortify[0];
-
- # Some build systems enable/disable fortify source multiple times, check
- # the final result.
- my $disable_pos = 0;
- foreach my $flag (@def_cppflags_fortify_bad) {
+ my $bad_pos = 0;
+ foreach my $flag (@{$bad_flags}) {
while ($line =~ /$flag/g) {
- if ($disable_pos < $+[0]) {
- $disable_pos = $+[0];
+ if ($bad_pos < $+[0]) {
+ $bad_pos = $+[0];
}
}
}
- my $enable_pos = 0;
- while ($line =~ /$fortify_source/g) {
- $enable_pos = $+[0];
+ my $good_pos = 0;
+ while ($line =~ /$good_flag/g) {
+ $good_pos = $+[0];
}
- if ($enable_pos > $disable_pos) {
+ if ($good_pos > $bad_pos) {
return 0;
}
+ return 1;
+}
+
+sub cppflags_fortify_broken {
+ my ($line, $missing_flags) = @_;
+ # $def_cppflags_fortify[0] must be -D_FORTIFY_SOURCE=2!
+ my $fortify_source = $def_cppflags_fortify[0];
+
+ # Some build systems enable/disable fortify source multiple times, check
+ # the final result.
+ if (not flag_overwritten($line,
+ $fortify_source,
+ \@def_cppflags_fortify_bad)) {
+ return 0;
+ }
push @{$missing_flags}, $fortify_source;
return 1;
}
+sub cflags_stack_broken {
+ my ($line, $missing_flags, $strong) = @_;
+
+ my $flag = $strong ? $def_cflags_stack_strong[0]
+ : $def_cflags_stack[0];
+
+ if (not flag_overwritten($line, $flag, \@def_cflags_stack_bad)) {
+ return 0;
+ }
+ push @{$missing_flags}, $flag;
+ return 1;
+}
+
# Modifies $missing_flags_ref array.
sub pic_pie_conflict {
my ($line, $pie, $missing_flags_ref, @flags_pie) = @_;
}
sub is_non_verbose_build {
- my ($line, $skip_ref, $input_ref, $line_offset, $line_count) = @_;
+ my ($line, $cargo, $skip_ref, $input_ref, $line_offset, $line_count) = @_;
if ($line =~ /$libtool_regex/o) {
# libtool's --silent hides the real compiler flags.
if (not (index($line, 'checking if you want to see long compiling messages... no') == 0
or $line =~ /^\s*\[?(?:CC|CCLD|C\+\+|CXX|CXXLD|LD|LINK)\]?\s+(.+?)$/
- or $line =~ /^\s*[Cc]ompiling\s+(.+?)(?:\.\.\.)?$/
+ or $line =~ /^\s*[][\/0-9 ]*[Cc]ompiling\s+(.+?)(?:\.\.\.)?$/
or $line =~ /^\s*[Bb]uilding (?:program|shared library)\s+(.+?)$/
or $line =~ /^\s*\[[\d ]+%\] Building (?:C|CXX) object (.+?)$/)) {
return 0;
# C++ compiler setting.
return 0 if $line =~ /^\s*C\+\+.+?:\s+(?:yes|no)\s*$/;
return 0 if $line =~ /^\s*C\+\+ Library: stdc\+\+$/;
+ return 0 if $line =~ /^\s*CXX\s*:\s*g\+\+\s*$/;
# "Compiling" non binary files.
- return 0 if $line =~ /^\s*Compiling \S+\.(?:py|el)['"]?\s*(?:\.\.\.)?$/;
+ return 0 if $line =~ /^\s*Compiling \S+\.(?:py|pyx|el)['"]?\s*(?:\.\.\.|because it changed\.)?$/;
+ return 0 if $line =~ /^\s*[Cc]ompiling catalog \S+\.po\b/;
+ # cargo build
+ return 0 if $cargo and $line =~ m{^\s*Compiling\s+\S+\s+v\S+(?:\s+\(/(?:<<PKGBUILDDIR>>|builds/\S+)\))?$};
# "Compiling" with no file name.
if ($line =~ /^\s*[Cc]ompiling\s+(.+?)(?:\.\.\.)?$/) {
# $file_extension_regex may need spaces around the filename.
my @result = ();
foreach my $flag (@flags) {
# Compile flag regexp for faster execution.
- my $regex = qr/\s$flag(?:\s|\\)/;
+ my $regex = qr/\s(['"]?)$flag\1(?:\s|\\)/;
# Store flag name in replacement string for correct flags in messages
# with qr//ed flag regexps.
}
if ($option_version) {
print <<"EOF";
-blhc $VERSION Copyright (C) 2012-2018 Simon Ruderich
+blhc $VERSION Copyright (C) 2012-2024 Simon Ruderich
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
}
# Precompile ignore line regexps, also anchor at beginning and end of line.
+# Additional entries are also extracted from the build log, see below.
foreach my $ignore (@option_ignore_line) {
$ignore = qr/^$ignore$/;
}
my $harden_fortify = 1;
my $harden_stack = 1;
my $harden_stack_strong = 1;
+ my $harden_stack_clash = 1;
+ my $harden_branch = 1;
my $harden_relro = 1;
my $harden_bindnow = $option_bindnow; # defaults to 0
my $harden_pie = $option_pie; # defaults to 0
- # Does this build log use ada? Ada also uses gcc as compiler but uses
- # different CFLAGS. But only perform ada checks if an ada compiler is used
- # for performance reasons.
- my $ada = 0;
- # Fortran also requires different CFLAGS.
- my $fortran = 0;
-
# Number of parallel jobs to prevent false positives when detecting
# non-verbose builds. As not all jobs declare the number of parallel jobs
# use a large enough default.
$disable_harden_pie = 1;
}
+ # Ignore additional false positives if cargo/rust is used
+ my $cargo = 0;
+
my $number = 0;
while (my $line = <$fh>) {
$number++;
my $disable = 1;
my $disable_strong = 1;
+ my $disable_clash = 1;
+ my $disable_branch = 1;
if ($line =~ /\bdpkg-dev_(\S+)/) {
if (Dpkg::Version::version_compare($1, '1.16.1') >= 0) {
if (Dpkg::Version::version_compare($1, '1.18.15') >= 0) {
$disable_harden_pie = 1;
}
+ if (Dpkg::Version::version_compare($1, '1.22.0') >= 0) {
+ $disable_clash = 0;
+ $disable_branch = 0;
+ }
}
if ($disable) {
if ($disable_strong) {
$harden_stack_strong = 0;
}
+ if ($disable_clash) {
+ $harden_stack_clash = 0;
+ }
+ if ($disable_branch) {
+ $harden_branch = 0;
+ }
}
# The following two versions of CMake in Debian obeyed CPPFLAGS, but
next FILE;
}
- # Ada compiler.
- if ($line =~ /\bgnat\b/) {
- $ada = 1;
- }
- # Fortran compiler.
- if ($line =~ /\bgfortran\b/) {
- $fortran = 1;
+ if ($line =~ /\bcargo\b/) {
+ $cargo = 1;
}
}
# Detect architecture automatically unless overridden.
if (not $arch
+ and index($line, 'dpkg-buildpackage: info: host architecture ') == 0) {
+ $arch = substr $line, 43, -1; # -1 to ignore '\n' at the end
+ # Older versions of dpkg-buildpackage
+ } elsif (not $arch
and index($line, 'dpkg-buildpackage: host architecture ') == 0) {
$arch = substr $line, 37, -1; # -1 to ignore '\n' at the end
}
}
+ # Permit dynamic excludes from within the build log to ignore false
+ # positives. Cannot use a separate config file as we often only have
+ # the build log itself.
+ if (index($line, 'blhc: ignore-line-regexp: ') == 0) {
+ my $ignore = substr $line, 26, -1; # -1 to ignore '\n' at the end
+ push @option_ignore_line, qr/^$ignore$/;
+ next;
+ }
+
next if $line =~ /^\s*#/;
# Ignore compiler warnings for now.
next if $line =~ /$warning_regex/o;
# Check if this line indicates a non verbose build.
my $skip = 0;
- $non_verbose |= is_non_verbose_build($line, \$skip);
+ $non_verbose |= is_non_verbose_build($line, $cargo, \$skip);
next if $skip;
- # One line may contain multiple commands (";"). Treat each one as
- # single line. parse_line() is slow, only use it when necessary.
- my @line = (index($line, ';') == -1)
+ # Treat each command as a single line so we don't ignore valid
+ # commands when handling false positives. split_line() is slow, only
+ # use it when necessary.
+ my @line = ($line !~ /(?:;|&&|\|\|)/)
? ($line)
- : map {
- # Ensure newline at the line end - necessary for
- # correct parsing later.
- $_ =~ s/\s+$//;
- $_ .= "\n";
- } Text::ParseWords::parse_line(';', 1, $line);
+ : split_line($line);
foreach my $line (@line) {
if ($continuation) {
$continuation = 0;
$complete_line = undef;
}
+ my $noenv = $line;
+ # Strip (basic) environment variables for compiler detection. This
+ # prevents false positives when environment variables contain
+ # compiler binaries. Nested quotes, command substitution, etc. is
+ # not supported.
+ $noenv =~ s/^
+ \s*
+ (?:
+ [a-zA-Z_]+ # environment variable name
+ =
+ (?:
+ [^\s"'\$`\\]+ # non-quoted string
+ |
+ '[^"'\$`\\]*' # single-quoted string
+ |
+ "[^"'\$`\\]*" # double-quoted string
+ )
+ \s+
+ )*
+ //x;
# Ignore lines with no compiler commands.
next if not $non_verbose
- and not $line =~ /$cc_regex_normal/o;
+ and not $noenv =~ /$cc_regex_normal/o;
# Ignore lines with no filenames with extensions. May miss some
# non-verbose builds (e.g. "gcc -o test" [sic!]), but shouldn't be
# a problem as the log will most likely contain other non-verbose
# optional compiler options, don't allow
# "everything" here to prevent false negatives
\s*(?:\s-\S+)*\s*$}xo;
+ # `echo` is never a compiler command
+ next if $line =~ /^\s*echo\s/;
+ # Ignore calls to `make` because they can contain environment
+ # variables which look like compiler commands, e.g. CC=).
+ next if $line =~ /^\s*make\s/;
# `moc-qt4`/`moc-qt5` contain '-I.../linux-g++' in their command
# line (or similar for other architectures) which gets recognized
# as a compiler line, but `moc-qt*` is only a preprocessor for Qt
# C++ files. No hardening flags are relevant during this step,
# thus ignore `moc-qt*` lines. The resulting files will be
# compiled in a separate step (and therefore checked).
- next if $line =~ m{^\S+/bin/moc(?:-qt[45])?
+ next if $line =~ m{^\S+(?:/bin/moc(?:-qt[45])?|/lib/qt6/libexec/moc)
\s.+\s
-I\S+/mkspecs/[a-z]+-g\++(?:-64)?
\s}x;
+ # nvcc is not a regular C compiler
+ next if $line =~ m{^\S+/bin/nvcc\s};
# Ignore false positives when the line contains only CC=gcc but no
# other gcc command.
if ($line =~ /(.*)CC=$cc_regex_full(.*)/o) {
# look like a compiler executable thus causing the line to be
# treated as a normal compiler line.
next if $line =~ m{^\s*rm\s+};
+ next if $line =~ m{^\s*dwz\s+};
# Some build systems emit "gcc > file".
- next if $line =~ m{$cc_regex_normal\s*>\s*\S+};
+ next if $line =~ m{$cc_regex_normal\s*>\s*\S+}o;
+ # Hex output may contain "cc".
+ next if $line =~ m#(?:\b[0-9a-fA-F]{2,}\b\s*){5}#;
+ # Meson build output
+ next if $line =~ /^C\+\+ linker for the host machine: /;
+ # Embedded `gcc -print-*` commands
+ next if $line =~ /`$cc_regex_normal\s*[^`]*-print-\S+`/;
+ # cmake checking for compiler flags without setting CPPFLAGS
+ next if $line =~ m{^\s*/usr/(bin|lib)/(ccache/)?c\+\+ (?:-std=\S+ )?-dM -E -c /usr/share/cmake-\S+/Modules/CMakeCXXCompilerABI\.cpp};
+ # Some rustc lines look like linker commands
+ next if $cargo and $line =~ /$rustc_regex/o;
# Check if additional hardening options were used. Used to ensure
# they are used for the complete build.
}
if (scalar @input == 0) {
- if (not $option_buildd) {
- print "No compiler commands!\n";
- $exit |= $exit_code{no_compiler_commands};
- } else {
- print "$buildd_tag{no_compiler_commands}||\n";
+ if (not $cargo) {
+ if (not $option_buildd) {
+ print "No compiler commands!\n";
+ $exit |= $exit_code{no_compiler_commands};
+ } else {
+ print "$buildd_tag{no_compiler_commands}||\n";
+ }
}
next FILE;
}
}
# Option or auto detected.
+ my @harden_branch_flags;
if ($arch) {
- # The following was partially copied from dpkg-dev 1.19.0.5
- # (/usr/share/perl5/Dpkg/Vendor/Debian.pm, _add_build_flags()),
- # copyright Raphaël Hertzog <hertzog@debian.org>, Guillem Jover
- # <guillem@debian.org>, Kees Cook <kees@debian.org>, Canonical, Ltd.
- # licensed under GPL version 2 or later. Keep it in sync.
+ # The following was partially copied from dpkg-dev 1.22.0
+ # (/usr/share/perl5/Dpkg/Vendor/Debian.pm, set_build_features and
+ # _add_build_flags()), copyright Raphaël Hertzog <hertzog@debian.org>,
+ # Guillem Jover <guillem@debian.org>, Kees Cook <kees@debian.org>,
+ # Canonical, Ltd. licensed under GPL version 2 or later. Keep it in
+ # sync.
require Dpkg::Arch;
my ($os, $cpu);
}
my %builtin_pie_arch = map { $_ => 1 } qw(
- amd64 arm64 armel armhf hurd-i386 i386 kfreebsd-amd64 kfreebsd-i386
- mips mipsel mips64el powerpc ppc64 ppc64el s390x sparc sparc64
+ amd64
+ arm64
+ armel
+ armhf
+ hurd-amd64
+ hurd-i386
+ i386
+ kfreebsd-amd64
+ kfreebsd-i386
+ loong64
+ mips
+ mips64
+ mips64el
+ mips64r6
+ mips64r6el
+ mipsel
+ mipsn32
+ mipsn32el
+ mipsn32r6
+ mipsn32r6el
+ mipsr6
+ mipsr6el
+ powerpc
+ ppc64
+ ppc64el
+ riscv64
+ s390x
+ sparc
+ sparc64
);
# Disable unsupported hardening options.
- if ($os !~ /^(?:linux|kfreebsd|knetbsd|hurd)$/
- or $cpu =~ /^(?:hppa|avr32)$/) {
+ if ($disable_harden_pie and exists $builtin_pie_arch{$arch}) {
+ $harden_pie = 0;
+ }
+ if ($os !~ /^(?:linux|kfreebsd|hurd)$/
+ or $cpu =~ /^(?:alpha|hppa|ia64)$/) {
$harden_pie = 0;
}
if ($cpu =~ /^(?:ia64|alpha|hppa|nios2)$/ or $arch eq 'arm') {
$harden_stack = 0;
$harden_stack_strong = 0;
}
- if ($cpu =~ /^(?:ia64|hppa|avr32)$/) {
+ if ($arch !~ /^(?:amd64|arm64|armhf|armel)$/) {
+ $harden_stack_clash = 0;
+ }
+ if ($cpu =~ /^(?:ia64|hppa)$/) {
$harden_relro = 0;
$harden_bindnow = 0;
}
-
- if ($disable_harden_pie and exists $builtin_pie_arch{$arch}) {
- $harden_pie = 0;
+ if ($cpu eq 'amd64') {
+ @harden_branch_flags = @def_cflags_branch_amd64;
+ } elsif ($cpu eq 'arm64') {
+ @harden_branch_flags = @def_cflags_branch_arm64;
}
}
@cflags = (@cflags, @def_cflags_stack);
@cxxflags = (@cxxflags, @def_cflags_stack);
}
+ if ($harden_stack_clash) {
+ @cflags = (@cflags, @def_cflags_stack_clash);
+ @cxxflags = (@cxxflags, @def_cflags_stack_clash);
+ }
if ($harden_fortify) {
@cflags = (@cflags, @def_cflags_fortify);
@cxxflags = (@cxxflags, @def_cflags_fortify);
@cflags = (@cflags, @def_cflags_format);
@cxxflags = (@cxxflags, @def_cflags_format);
}
+ if ($harden_branch and @harden_branch_flags) {
+ @cflags = (@cflags, @harden_branch_flags);
+ @cxxflags = (@cxxflags, @harden_branch_flags);
+ }
if ($harden_relro) {
@ldflags = (@ldflags, @def_ldflags_relro);
}
}
# Ada doesn't support format hardening flags, see #680117 for more
- # information. Same for fortran. Filter them out if either language is
- # used.
+ # information. Same for fortran.
my @cflags_backup;
- my @cflags_noformat;
- if (($ada or $fortran) and $harden_format) {
- @cflags_noformat = grep {
- my $ok = 1;
- foreach my $flag (@def_cflags_format) {
- $ok = 0 if $_ eq $flag;
- }
- $ok;
- } @cflags;
- }
+ my @cflags_noformat = grep {
+ my $ok = 1;
+ foreach my $flag (@def_cflags_format) {
+ $ok = 0 if $_ eq $flag;
+ }
+ $ok;
+ } @cflags;
# Hack to fix cppflags_fortify_broken() if --ignore-flag
# -D_FORTIFY_SOURCE=2 is used to ignore missing fortification. Only works
my $skip = 0;
if ($input_nonverbose[$i]
- and is_non_verbose_build($line, \$skip,
+ and is_non_verbose_build($line, $cargo, \$skip,
\@input, $i, $parallel)) {
if (not $option_buildd) {
error_non_verbose_build($line, $input_number[$i]);
and extension_found(\%extensions_compile_cpp, @extensions)) {
$compile = 0;
$compile_cpp = 1;
- # Ada needs special CFLAGS, use them if only ada files are compiled.
- } elsif ($ada
- and extension_found(\%extensions_ada, @extensions)) {
+ # Ada needs special CFLAGS
+ } elsif (extension_found(\%extensions_ada, @extensions)) {
$restore_cflags = 1;
$preprocess = 0; # Ada uses no CPPFLAGS
@cflags_backup = @cflags;
@cflags = @cflags_noformat;
- # Same for fortran.
- } elsif ($fortran
- and extension_found(\%extensions_fortran, @extensions)) {
+ # Same for fortran
+ } elsif (extension_found(\%extensions_fortran, @extensions)) {
$restore_cflags = 1;
@cflags_backup = @cflags;
@cflags = @cflags_noformat;
# Check hardening flags.
my @missing;
- if ($compile and not all_flags_used($line, \@missing, @cflags)
+ if ($compile and (not all_flags_used($line, \@missing, @cflags)
+ or (($harden_stack or $harden_stack_strong)
+ and cflags_stack_broken($line, \@missing,
+ $harden_stack_strong)))
# Libraries linked with -fPIC don't have to (and can't) be
# linked with -fPIE as well. It's no error if only PIE flags
# are missing.
See F<README> for details about performed checks, auto-detection and
limitations.
+=head1 FALSE POSITIVES
+
+To suppress false positives you can embed the following string in the build
+log:
+
+ blhc: ignore-line-regexp: REGEXP
+
+All lines fully matching REGEXP (see B<--ignore-line> for details) will be
+ignored. The string can be embedded multiple times to ignore different
+regexps.
+
+Please use this feature sparingly so that missing flags are not overlooked. If
+you find false positives which affect more packages please report a bug.
+
+To generate this string simply use echo in C<debian/rules>; make sure to use @
+to suppress the echo command itself as it could also trigger a false positive.
+If the build process takes a long time edit the C<.build> file in place and
+tweak the ignore string until B<blhc --all --debian package.build> no longer
+reports any false positives.
+
=head1 OPTIONS
=over 8
=head1 LICENSE AND COPYRIGHT
-Copyright (C) 2012-2018 by Simon Ruderich
+Copyright (C) 2012-2024 by Simon Ruderich
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
ruderich.org/simon / blhc / blhc.git / blobdiff