DPKG-ARCHITECTURE(1) User Contributed Perl Documentation DPKG-ARCHITECTURE(1)NAMEdpkg-architecture - set and determine the architecture for package
building
SYNOPSISdpkg-architecture [options] [action]
Valid options: -aDebian-Architecture -tGnu-System-Type -f
Valid actions: -l, -qVariable-Name, -s, -u, -c Command
DESCRIPTIONdpkg-architecture does provide a facility to determine and set the
build and host architecture for package building.
OVERVIEW
The build architecture is always determined by an external call to
dpkg, and can not be set at the command line.
You can specify the host architecture by providing one or both of the
options -a and -t. The default is determined by an external call to
gcc, or the same as the build architecture if CC or gcc are both not
available. One out of -a and -t is sufficient, the value of the other
will be set to a usable default. Indeed, it is often better to only
specify one, because dpkg-architecture will warn you if your choice
doesn't match the default.
The default action is -l, which prints the environment variales, one
each line, in the format VARIABLE=value. If you are only interested in
the value of a single variable, you can use -q. If you specify -s, it
will output an export command. This can be used to set the environment
variables using eval. -u does return a similar command to unset all
variables. -c does execute a command in an environment which has all
variables set to the determined value.
Existing environment variables with the same name as used by the
scripts are not overwritten, except if the -f force flag is present.
This allows the user to override a value even when the call to dpkg-
architecture is buried in some other script (for example dpkg-
buildpackage).
TERMS
build machine
The machine the package is built on.
host machine
The machine the package is built for.
Debian Architecture
The Debian archietcture string, which specifies the binary tree in
the FTP archive. Examples: i386, sparc, hurd-i386.
GNU System Type
An architecture specification string consisting of two or three
parts, cpu-system or cpu-vendor-system. Examples: i386-linux,
sparc-linux, i386-gnu.
EXAMPLES
dpkg-buildpackage accepts the -a option and passes it to dpkg-
architecture. Other examples:
CC=i386-gnu-gcc dpkg-architecture "-c" debian/rules build
eval `dpkg-architecture "-u"`
VARIABLES
The following variables are set by dpkg-architecture:
DEB_BUILD_ARCH
The Debian architecture of the build machine.
DEB_BUILD_GNU_TYPE
The GNU system type of the build machine.
DEB_BUILD_GNU_CPU
The CPU part of DEB_BUILD_GNU_TYPE
DEB_BUILD_GNU_SYSTEM
The System part of DEB_BUILD_GNU_TYPE
DEB_HOST_ARCH
The Debian architecture of the host machine.
DEB_HOST_GNU_TYPE
The GNU system type of the host machine.
DEB_HOST_GNU_CPU
The CPU part of DEB_HOST_GNU_TYPE
DEB_HOST_GNU_SYSTEM
The System part of DEB_HOST_GNU_TYPE
DEBIAN/RULES
The environment variables set by dpkg-architecture are passed to
debian/rules as make variables (see make documentation). However, you
should not rely on them, as this breaks manual invocation of the
script. Instead, you should always initialize them using dpkg-
architecture with the -q option. Here are some examples, which also
show how you can improve the cross compilation support in your package:
Instead of:
ARCH=`dpkg --print-architecture` configure $(ARCH)-linux
please use the following:
DEB_BUILD_GNU_TYPE := $(shell dpkg-architecture -qDEB_BUILD_GNU_TYPE)
DEB_HOST_GNU_TYPE := $(shell dpkg-architecture -qDEB_HOST_GNU_TYPE)
configure --build=$(DEB_BUILD_GNU_TYPE) --host=$(DEB_HOST_GNU_TYPE)
Instead of:
ARCH=`dpkg --print-architecture` ifeq ($(ARCH),alpha)
... endif
please use:
DEB_HOST_ARCH := $(shell dpkg-architecture -qDEB_HOST_ARCH)
ifeq ($(DEB_HOST_ARCH),alpha)
... endif
In general, calling dpkg in the rules file to get architecture
information is deprecated (until you want to provide backward
compatibility, see below). Especially the --print-architecture option
is unreliable since we have Debian architectures which don't equal a
processor name.
BACKWARD COMPATIBILITY
When providing a new facility, it is always a good idea to stay
compatible with old versions of the programs. Note that dpkg-
architecture does not affect old debian/rules files, so the only thing
to consider is using old versions of dpkg-dev with new debian/rules
files. The following does the job:
DEB_BUILD_ARCH := $(shell dpkg --print-installation-architecture)
DEB_BUILD_GNU_CPU := $(patsubst hurd-%,%,$(DEB_BUILD_ARCH)) ifeq
($(filter-out hurd-%,$(DEB_BUILD_ARCH)),)
DEB_BUILD_GNU_SYSTEM := gnu else
DEB_BUILD_GNU_SYSTEM := linux endif
DEB_BUILD_GNU_TYPE=$(DEB_BUILD_GNU_CPU)-$(DEB_BUILD_GNU_SYSTEM)
DEB_HOST_ARCH := $(DEB_BUILD_ARCH) DEB_HOST_GNU_CPU :=
$(DEB_BUILD_GNU_CPU) DEB_HOST_GNU_SYSTEM := $(DEB_BUILD_GNU_SYSTEM)
DEB_HOST_GNU_TYPE := $(DEB_BUILD_GNU_TYPE)
Put a subset of these lines at the top of your debian/rules file; these
default values will be overwritten if dpkg-architecture is used.
You don't need the full set. Choose a consistent set which contains the
values you use in the rules file. For example, if you only need the
host Debian architecture, `DEB_HOST_ARCH=`dpkg
--print-installation-architecture` is sufficient (this is indeed the
Debian architecture of the build machine, but remember that we are only
trying to be backward compatible with native compilation).
SEE ALSO
dpkg-buildpackage dpkg-cross
CONTACT
If you have questions about the usage of the make variables in your
rules files, or about cross compilation support in your packages,
please email me. The address is Marcus Brinkmann <brinkmd@debian.org>.
perl v5.16.2 2004-03-08 DPKG-ARCHITECTURE(1)