---
name: "hardened-cc"
section: "1"
platform: "linux"
package: "hardening-wrapper"
version: "2.6"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/hardened-cc"
---

# hardened-cc(1)

gcc wrapper to enforce hardening toolchain improvements

## NAME

hardened-cc - gcc wrapper to enforce hardening toolchain improvements

## SYNOPSIS

**export DEB\_BUILD\_HARDENING=1**\

**gcc** *...*

## DESCRIPTION

The **hardened-cc** wrapper is normally used by calling **gcc** as usual when **DEB\_BUILD\_HARDENING** is set to 1. It will configure the necessary toolchain hardening features. By default, all features are enabled. If a given feature does not work correctly and needs to be disabled, the corresponding environment variables mentioned below can be set to 0.

## ENVIRONMENT

- DEB\_BUILD\_HARDENING=1

  Enable hardening features.

- DEB\_BUILD\_HARDENING\_DEBUG=1

  Print the full resulting gcc command line to STDERR before calling gcc.

- DEB\_BUILD\_HARDENING\_OUTPUT=/some/path/debug.log

  Instead of using STDERR for debugging, redirect to the given path. Some builds are very sensitive to unexpected STDERR output.

- DEB\_BUILD\_HARDENING\_STACKPROTECTOR=0

  Disable stack overflow protection. See README.Debian for details.

- DEB\_BUILD\_HARDENING\_RELRO=0

  Disable read-only linker sections. See README.Debian for details.

- DEB\_BUILD\_HARDENING\_FORTIFY=0

  Don't fortify several standard functions. See README.Debian for details.

- DEB\_BUILD\_HARDENING\_PIE=0

  Don't build position independent executables. See README.Debian for details.

- DEB\_BUILD\_HARDENING\_FORMAT=0

  Disable unsafe format string usage errors. See README.Debian for details.

## NOTES

System-wide settings can be added to */etc/hardening-wrapper.conf*, one per line.

The real **gcc** symlinks are renamed **gcc.real**, and a diversion is registered with [**dpkg-divert**(1)](/dpkg-divert/1.md). Thus **hardened-cc**'s idea of the default **gcc** is dictated by whatever package installed */usr/bin/gcc*.

## SEE ALSO

[**hardened-ld**(1)](/hardened-ld/1.md) [**gcc**(1)](/gcc/1.md)