dpkg-buildflags(1)						    dpkg suite							dpkg-buildflags(1)

NAME

       dpkg-buildflags - returns build flags to use during package build

SYNOPSIS

       dpkg-buildflags [option...] command

DESCRIPTION

       dpkg-buildflags	is a tool to retrieve compilation flags to use during build of Debian packages.  The default flags are defined by the ven-
       dor but they can be extended/overriden in several ways:

       1.     system-wide with /etc/dpkg/buildflags.conf;

       2.     for the current user with $XDG_CONFIG_HOME/dpkg/buildflags.conf where $XDG_CONFIG_HOME defaults to $HOME/.config;

       3.     temporarily with environment variables (see section ENVIRONMENT).

       The configuration files can contain two types of directives:

       SET flag value
	      Override the flag named flag to have the value value.

       APPEND flag value
	      Extend the flag named flag with the options given in value.  A space is prepended to the appended value if the flag's current  value
	      is non-empty.

       The configuration files can contain comments on lines starting with a hash (#). Empty lines are also ignored.

COMMANDS

       --list Print  the  list of flags supported by the current vendor (one per line). See the SUPPORTED FLAGS section for more information about
	      them.

       --export=format
	      Print to standard output shell (if format is sh) or make (if format is make) commands that can be used to export all the compilation
	      flags  in the environment. If the format value is not given, sh is assumed. Only compilation flags starting with an upper case char-
	      acter are included, others are assumed to not be suitable for the environment.

       --get flag
	      Print the value of the flag on standard output. Exits with 0 if the flag is known otherwise exits with 1.

       --origin flag
	      Print the origin of the value that is returned by --get. Exits with 0 if the flag is known otherwise exits with 1. The origin can be
	      one of the following values:

	      vendor the original flag set by the vendor is returned;

	      system the flag is set/modified by a system-wide configuration;

	      user   the flag is set/modified by a user-specific configuration;

	      env    the flag is set/modified by an environment-specific configuration.

       --help Show the usage message and exit.

       --version
	      Show the version and exit.

SUPPORTED FLAGS

       CFLAGS Options  for the C compiler. The default value set by the vendor includes -g and the default optimization level (-O2 usually, or -O0
	      if the DEB_BUILD_OPTIONS environment variable defines noopt).

       CPPFLAGS
	      Options for the C preprocessor. Default value: empty.

       CXXFLAGS
	      Options for the C++ compiler. Same as CFLAGS.

       FFLAGS Options for the Fortran compiler. Same as CFLAGS.

       LDFLAGS
	      Options passed to the compiler when linking executables or shared objects (if the linker is called directly, then -Wl and , have	to
	      be stripped from these options). Default value: empty.

FILES

       /etc/dpkg/buildflags.conf
	      System wide configuration file.

       $XDG_CONFIG_HOME/dpkg/buildflags.conf or $HOME/.config/dpkg/buildflags.conf
	      User configuration file.

ENVIRONMENT

       DEB_flag_SET
	      This variable can be used to force the value returned for the given flag.

       DEB_flag_APPEND
	      This variable can be used to append supplementary options to the value returned for the given flag.

       DEB_BUILD_OPTIONS
	      When  used  with	the  hardening-wrapper	package,  the  values  hardening  and  nohardening will be converted into their respective
	      DEB_BUILD_HARDENING values.  The hardening option can also include (optionally prefixed with no ) the following sub-options:  stack-
	      protector  format  fortify pie relro For example, DEB_BUILD_OPTIONS=hardening=nopie would cause DEB_BUILD_HARDENING_PIE=0 to be set,
	      or DEB_BUILD_OPTIONS=nohardening would cause DEB_BUILD_HARDENING=0 to be	set.   See  http://wiki.debian.org/Hardening  for  further
	      details.

AUTHOR

       Copyright (C) 2010 Raphael Hertzog

       This is free software; see the GNU General Public Licence version 2 or later for copying conditions. There is NO WARRANTY.

Debian Project							    2010-07-29							dpkg-buildflags(1)