+# CONSTANTS/VARIABLES
+
+# Regex to catch compiler commands.
+my $cc_regex = qr/(?:[a-z0-9_]+-(?:linux|kfreebsd)-gnu(?:eabi|eabihf)?-)?
+ (?:(?<!\.)cc|gcc|g\+\+|c\+\+)
+ (?:-[\d.]+)?/x;
+# 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',
+ '-O(?:2|3)',
+);
+my @cflags_format = (
+ '-Wformat',
+ '-Wformat-security',
+ '-Werror=format-security',
+);
+my @cflags_fortify = (
+ # fortify needs at least -O1, but -O2 is recommended anyway
+);
+my @cflags_stack = (
+ '-fstack-protector',
+ '--param=ssp-buffer-size=4',
+);
+my @cflags_pie = (
+ '-fPIE',
+);
+my @cppflags = ();
+my @cppflags_fortify = (
+ '-D_FORTIFY_SOURCE=2',
+);
+my @ldflags = ();
+my @ldflags_relro = (
+ '-Wl,(-z,)?relro',
+);
+my @ldflags_bindnow = (
+ '-Wl,(-z,)?now',
+);
+my @ldflags_pie = (
+ '-fPIE',
+ '-pie',
+);
+# Renaming rules for the output so the regex parts are not visible.
+my %flag_renames = (
+ '-O(?:2|3)' => '-O2',
+ '-Wl,(-z,)?relro' => '-Wl,-z,relro',
+ '-Wl,(-z,)?now' => '-Wl,-z,now',
+);
+
+