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bsd.README

@()bsd.README 8.2 (Berkeley) 4/2/94 # $FreeBSD: src/share/mk/bsd.README,v 1.28.2.1 2006/06/26 13:54:37 yar Exp $

This is the README file for the "include" files for the FreeBSD source tree. The files are installed in /usr/share/mk, and are by convention, named with the suffix ".mk". These files store several build options and should be handled with caution.

Note, this file is not intended to replace reading through the .mk files for anything tricky.

There are two main types of make include files. One type is the generally usable make include files, such as bsd.prog.mk and bsd.lib.mk. The other is the internal make include files, such as bsd.files.mk and bsd.man.mk, which can not/should not be used directly but are used by the other make include files. In most cases it is only interesting to include bsd.prog.mk or bsd.lib.mk.

bsd.cpu.mk              - sets CPU/arch-related variables
bsd.dep.mk              - handle Makefile dependencies
bsd.doc.mk              - building troff system documents
bsd.files.mk            - install of general purpose files
bsd.incs.mk             - install of include files
bsd.info.mk             - building GNU Info hypertext system
bsd.init.mk             - initialization for the make include files
bsd.kmod.mk             - building loadable kernel modules
bsd.lib.mk              - support for building libraries
bsd.libnames.mk         - define library names
bsd.links.mk            - install of links (sym/hard)
bsd.man.mk              - install of manual pages and their links
bsd.nls.mk              - build and install of NLS catalogs
bsd.obj.mk              - creating 'obj' directories and cleaning up
bsd.own.mk              - define common variables
bsd.port.mk             - building ports
bsd.port.post.mk        - building ports
bsd.port.pre.mk         - building ports
bsd.port.subdir.mk      - targets for building subdirectories for ports
bsd.prog.mk             - building programs from source files
bsd.snmpmod.mk          - building modules for the SNMP daemon bsnmpd
bsd.subdir.mk           - targets for building subdirectories
bsd.sys.mk              - common settings used for building FreeBSD sources
sys.mk                  - default rules for all makes

This file does not document bsd.port*.mk. They are documented in ports(7).

See also make(1), mkdep(1), style.Makefile(5) and `PMake - A Tutorial', located in /usr/share/doc/psd/12.make.


Random things worth knowing about this document:

If appropriate when documenting the variables the default value is indicated using square brackets e.g. [gzip]. In some cases the default value depend on other values (e.g. system architecture). In these cases the most common value is indicated.

This document contains some simple examples of the usage of the BSD make include files. For more examples look at the makefiles in the FreeBSD source tree.


RANDOM THINGS WORTH KNOWING:

The files are like C-style #include files, and pretty much behave like you'd expect. The syntax is slightly different in that a single '.' is used instead of the hash mark, i.e. ".include <bsd.prog.mk>".

One difference that will save you lots of debugging time is that inclusion of the file is normally done at the end of the Makefile. The reason for this is because .mk files often modify variables and behavior based on the values of variables set in the Makefile. To make this work, remember that the FIRST target found is the target that is used, i.e. if the Makefile has:

        a:
                echo a
        a:
                echo a number two

the command "make a" will echo "a". To make things confusing, the SECOND variable assignment is the overriding one, i.e. if the Makefile has:

        a=      foo
        a=      bar

        b:
                echo ${a}

the command "make b" will echo "bar". This is for compatibility with the way the V7 make behaved.

It's fairly difficult to make the BSD .mk files work when you're building multiple programs in a single directory. It's a lot easier split up the programs than to deal with the problem. Most of the agony comes from making the "obj" directory stuff work right, not because we switch to a new version of make. So, don't get mad at us, figure out a better way to handle multiple architectures so we can quit using the symbolic link stuff. (Imake doesn't count.)

The file .depend in the source directory is expected to contain dependencies for the source files. This file is read automatically by make after reading the Makefile.

The variable DESTDIR works as before. It's not set anywhere but will change the tree where the file gets installed.

The profiled libraries are no longer built in a different directory than the regular libraries. A new suffix, ".po", is used to denote a profiled object.


The include file <sys.mk> has the default rules for all makes, in the BSD environment or otherwise. You probably don't want to touch this file.


The include file <bsd.man.mk> handles installing manual pages and their links.

It has three targets:

        all-man:
                build manual pages.
        maninstall:
                install the manual pages and their links.
        manlint:
                verify the validity of manual pages.

It sets/uses the following variables:

MANDIR Base path for manual installation.

MANGRP Manual group.

MANOWN Manual owner.

MANMODE Manual mode.

MANSUBDIR       Subdirectory under the manual page section, i.e. "/vax"
                or "/tahoe" for machine specific manual pages.

MAN             The manual pages to be installed (use a .1 - .9 suffix).

MLINKS          List of manual page links (using a .1 - .9 suffix).  The
                linked-to file must come first, the linked file second,
                and there may be multiple pairs.  The files are soft-linked.

The include file <bsd.man.mk> includes a file named "../Makefile.inc" if it exists.


The include file <bsd.own.mk> contains the owners, groups, etc. for both manual pages and binaries.

It has no targets.

It sets/uses the following variables:

BINGRP Binary group.

BINOWN Binary owner.

BINMODE Binary mode.

MANDIR Base path for manual installation.

MANGRP Manual group.

MANOWN Manual owner.

MANMODE Manual mode.

This file is generally useful when building your own Makefiles so that they use the same default owners etc. as the rest of the tree.


The include file <bsd.prog.mk> handles building programs from one or more source files, along with their manual pages. It has a limited number of suffixes, consistent with the current needs of the BSD tree.

It has seven targets:

all

build the program and its manual page

clean

remove the program and any object files.

cleandir

remove all of the files removed by the target clean, as well as .depend, tags, and any manual pages.

depend

make the dependencies for the source files, and store them in the file .depend.

install

install the program and its manual pages; if the Makefile does not itself define the target install, the targets beforeinstall and afterinstall may also be used to cause actions immediately before and after the install target is executed.

lint

run lint on the source files

tags

create a tags file for the source files.

It sets/uses the following variables:

BINGRP Binary group.

BINOWN Binary owner.

BINMODE Binary mode.

CLEANFILES      Additional files to remove and
CLEANDIRS       additional directories to remove during clean and cleandir
                targets.  "rm -f" and "rm -rf" used respectively.

CFLAGS          Flags to the compiler when creating C objects.

FILES           A list of non-executable files.
                The installation is controlled by the FILESNAME, FILESOWN,
                FILESGRP, FILESMODE, FILESDIR variables that can be
                further specialized by FILES<VAR>_<file>.

LDADD           Additional loader objects.  Usually used for libraries.
                For example, to load with the compatibility and utility
                libraries, use:

                        LDFILES=-lutil -lcompat

LDFLAGS         Additional loader flags.

LINKS           The list of binary links; should be full pathnames, the
                linked-to file coming first, followed by the linked
                file.  The files are hard-linked.  For example, to link
                /bin/test and /bin/[, use:

                        LINKS=  ${DESTDIR}/bin/test ${DESTDIR}/bin/[

MAN             Manual pages (should end in .1 - .9).  If no MAN variable
                is defined, "MAN=${PROG}.1" is assumed.

PROG            The name of the program to build.  If not supplied, nothing
                is built.

PROG_CXX        If defined, the name of the program to build.  Also
                causes <bsd.prog.mk> to link the program with the
                standard C++ library.  PROG_CXX overrides the value
                of PROG if PROG is also set.

PROGNAME        The name that the above program will be installed as, if
                different from ${PROG}.

SRCS            List of source files to build the program.  If SRCS is not
                defined, it's assumed to be ${PROG}.c or, if PROG_CXX is
                defined, ${PROG_CXX}.cc.

DPADD           Additional dependencies for the program.  Usually used for
                libraries.  For example, to depend on the compatibility and
                utility libraries use:

                        SRCLIB=${LIBCOMPAT} ${LIBUTIL}

                There is a predefined identifier for each (non-profiled,
                non-shared) library and object.  Library file names are
                transformed to identifiers by removing the extension and
                converting to upper case.

                There are no special identifiers for profiled or shared
                libraries or objects.  The identifiers for the standard
                libraries are used in DPADD.  This works correctly iff all
                the libraries are built at the same time.  Unfortunately,
                it causes unnecessary relinks to shared libraries when
                only the static libraries have changed.  Dependencies on
                shared libraries should be only on the library version
                numbers.

STRIP           The flag passed to the install program to cause the binary
                to be stripped.  This is to be used when building your
                own install script so that the entire system can be made
                stripped/not-stripped using a single nob.

SUBDIR          A list of subdirectories that should be built as well.
                Each of the targets will execute the same target in the
                subdirectories.

SCRIPTS         A list of interpreter scripts [file.{sh,csh,pl,awk,...}].
                The installation is controlled by the SCRIPTSNAME, SCRIPTSOWN,
                SCRIPTSGRP, SCRIPTSMODE, SCRIPTSDIR variables that can be
                further specialized by SCRIPTS<VAR>_<script>.

The include file <bsd.prog.mk> includes the file named "../Makefile.inc" if it exists, as well as the include file <bsd.man.mk>.

Some simple examples:

To build foo from foo.c with a manual page foo.1, use:

PROG= foo

.include <bsd.prog.mk>

To build foo from foo.c with a manual page foo.2, add the line:

MAN= foo.2

If foo does not have a manual page at all, add the line:

NO_MAN=

If foo has multiple source files, add the line:

SRCS= a.c b.c c.c d.c


The include file <bsd.subdir.mk> contains the default targets for building subdirectories. It has the same seven targets as <bsd.prog.mk>: all, clean, cleandir, depend, install, lint, and tags. For all of the directories listed in the variable SUBDIRS, the specified directory will be visited and the target made. There is also a default target which allows the command "make subdir" where subdir is any directory listed in the variable SUBDIRS.


The include file <bsd.lib.mk> has support for building libraries. It has the same seven targets as <bsd.prog.mk>: all, clean, cleandir, depend, install, lint, and tags. It has a limited number of suffixes, consistent with the current needs of the BSD tree.

It sets/uses the following variables:

LIBDIR Target directory for libraries.

LINTLIBDIR Target directory for lint libraries.

LIBGRP Library group.

LIBOWN Library owner.

LIBMODE Library mode.

LDADD Additional loader objects.

MAN The manual pages to be installed (use a .1 - .9 suffix).

SRCS            List of source files to build the library.  Suffix types
                .s, .c, and .f are supported.  Note, .s files are preferred
                to .c files of the same name.  (This is not the default for
                versions of make.)

The include file <bsd.lib.mk> includes the file named "../Makefile.inc" if it exists, as well as the include file <bsd.man.mk>.

It has rules for building profiled objects; profiled libraries are built by default.

Libraries are ranlib'd before installation.