make(1) includes are best explained by inspection of the code. Here are the system include files:
doc.project.mk is the main project
include file, which includes all the following include
files, as necessary.
doc.subdir.mk handles traversing of
the document tree during the build and install
processes.
doc.install.mk provides variables
that affect ownership and installation of documents.
doc.docbook.mk is included if
DOCFORMAT is docbook
and DOC is set.
By inspection:
DOCFORMAT?= docbook
MAINTAINER?= doc@FreeBSD.org
PREFIX?= /usr/local
PRI_LANG?= en_US.ISO8859-1
.if defined(DOC)
.if ${DOCFORMAT} == "docbook"
.include "doc.docbook.mk"
.endif
.endif
.include "doc.subdir.mk"
.include "doc.install.mk"DOCFORMAT and
MAINTAINER are assigned default values,
if these are not set by the document make file.
PREFIX is the prefix under which the
documentation building tools
are installed. For normal package and port installation,
this is /usr/local.
PRI_LANG should be set to whatever
language and encoding is natural amongst users these
documents are being built for. US English is the
default.
PRI_LANG does not affect which
documents can, or even will, be built. Its main use is
creating links to commonly referenced documents into the
FreeBSD documentation install root.
The .if defined(DOC) line is an
example of a make(1) conditional which, like in other
programs, defines behavior if some condition is true or if
it is false. defined is a function which
returns whether the variable given is defined or not.
.if ${DOCFORMAT} == "docbook", next,
tests whether the DOCFORMAT variable is
"docbook", and in this case, includes
doc.docbook.mk.
The two .endifs close the two above
conditionals, marking the end of their application.
This file is too long to explain in detail. These notes describe the most important features.
SUBDIR is a list of
subdirectories that the build process should go further
down into.
ROOT_SYMLINKS is the name of
directories that should be linked to the document
install root from their actual locations, if the current
language is the primary language (specified by
PRI_LANG).
COMPAT_SYMLINK is described in
the
Subdirectory Makefile
section.
Dependencies are described by
tuples, where to build
target:
dependency1 dependency2
...target, the given
dependencies must be built first.
After that descriptive tuple, instructions on how to build the target may be given, if the conversion process between the target and its dependencies are not previously defined, or if this particular conversion is not the same as the default conversion method.
A special dependency .USE defines
the equivalent of a macro.
_SUBDIRUSE: .USE
.for entry in ${SUBDIR}
@${ECHO} "===> ${DIRPRFX}${entry}"
@(cd ${.CURDIR}/${entry} && \
${MAKE} ${.TARGET:S/realpackage/package/:S/realinstall/install/} DIRPRFX=${DIRPRFX}${entry}/ )
.endforIn the above, _SUBDIRUSE is
now a macro which will execute the given commands when it is
listed as a dependency.
What sets this macro apart from other targets?
Basically, it is executed after the
instructions given in the build procedure it is listed as a
dependency to, and it does not adjust
.TARGET, which is the variable which
contains the name of the target currently being
built.
clean: _SUBDIRUSE
rm -f ${CLEANFILES}In the above, clean will use
the _SUBDIRUSE macro after it has
executed the instruction
rm -f ${CLEANFILES}. In effect, this
causes clean to go further and
further down the directory tree, deleting built files as it
goes down, not on the way back
up.
install and
package both go down the
directory tree calling the real versions of themselves
in the subdirectories
(realinstall and
realpackage
respectively).
clean removes files
created by the build process (and goes down the
directory tree too).
cleandir does the same, and
also removes the object directory, if any.
exists is another condition
function which returns true if the given file
exists.
empty returns true if the given
variable is empty.
target returns true if the given
target does not already exist.
.for provides a way to repeat a set
of instructions for each space-separated element in a
variable. It does this by assigning a variable to contain
the current element in the list being examined.
_SUBDIRUSE: .USE
.for entry in ${SUBDIR}
@${ECHO} "===> ${DIRPRFX}${entry}"
@(cd ${.CURDIR}/${entry} && \
${MAKE} ${.TARGET:S/realpackage/package/:S/realinstall/install/} DIRPRFX=${DIRPRFX}${entry}/ )
.endforIn the above, if SUBDIR is empty, no
action is taken; if it has one or more elements, the
instructions between .for and
.endfor would repeat for every element,
with entry being replaced with the value
of the current element.
All FreeBSD documents are available for download at https://download.freebsd.org/ftp/doc/
Questions that are not answered by the
documentation may be
sent to <freebsd-questions@FreeBSD.org>.
Send questions about this document to <freebsd-doc@FreeBSD.org>.