- GNU Project - Free Software Foundation
GNU Make is a tool which controls the generation of executables and othernon-source files of a program from the program's source files.
Make gets its knowledge of how to build your program from a filecalled the makefile, which lists each of the non-source filesand how to compute it from other files.When you write a program, youshould write a makefile for it, so that it is possible to use Make tobuild and install the program.Capabilities of MakeMake enables the end user to build and install your packagewithout knowing the details of how that is done -- because thesedetails are recorded in the makefile that you supply. Make figures out automatically which files it needs to update,based on which source files have changed.It also automaticallydetermines the proper order for updating files, in case one non-sourcefile depends on another non-source file.
As a result, if you change a few source files and then run Make, itdoes not need to recompile all of your program.It updates only thosenon-source files that depend directly or indirectly on the sourcefiles that you changed.Make is not limited to any particular language.For eachnon-source file in the program, the makefile specifies the shellcommands to compute it.These shell commands can run a compiler toproduce an object file, the linker to produce an executable,ar to update a library, or TeX or Makeinfo to formatdocumentation. Make is not limited to building a package.You can also use Maketo control installing or deinstalling a package, generate tags tables forit, or anything else you want to do often enough to make it worthwhile writing down how to do it. Make Rules and Targets
A rule in the makefile tells Make how to execute a series ofcommands in order to build a target file from source files.It also specifies a list of dependencies of the target file.This list should include all files (whether source files or other targets)which are used as inputs to the commands in the rule.
Here is what a simple rule looks like: target:dependencies ...commands...
When you run Make, you can specify particular targets to update;otherwise, Make updates the first target listed in the makefile.Ofcourse, any other target files needed as input for generating thesetargets must be updated first.
Make uses the makefile to figure out which target files ought to bebrought up to date, and then determines which of them actually need tobe updated.If a target file is newer than all of its dependencies,then it is already up to date, and it does not need to be regenerated.The other target files do need to be updated, but in the right order:each target file must be regenerated before it is used in regeneratingother targets. Advantages of GNU Make
GNU Make has many powerful features for use in makefiles, beyond whatother Make versions have.It can also regenerate, use, and then deleteintermediate files which need not be saved.
GNU Make also has a few simple features that are very convenient.Forexample, the -o file option which says ``pretend thatsource file file has not changed, even though it has changed.''This is extremely useful when you add a new macro to a header file.Most versions of Make will assume they must therefore recompile all thesource files that use the header file; but GNU Make gives you a way toavoid the recompilation, in the case where you know your change to theheader file does not require it.
However, the most important difference between GNU Make and mostversions of Make is that GNU Make is free software. Makefiles And Conventions
We have developed conventions for how to write Makefiles, which allGNU packages ought to follow.It is a good idea to follow theseconventions in your program even if you don't intend it to be GNUsoftware, so that users will be able to build your package justlike many other packages, and will not need to learn anything specialbefore doing so.
These conventions are found in the chapter``Makefile conventions'' (147 kcharacters) of the GNU CodingStandards (147 k characters). DownloadingMake
Makecan be found on the main GNU ftp server:http://ftp.gnu.org/gnu/make/(via HTTP) andftp://ftp.gnu.org/gnu/make/(via FTP).It can also be foundon the GNU mirrors;pleaseusea mirror if possible.Documentation
Documentation forMakeis available online, asis documentation for most GNU software.You mayalso find more information aboutMakeby runninginfo makeorman make,or by looking at/usr/share/doc/make/,/usr/local/doc/make/,or similar directories on your system.A brief summary is available byrunning make --help.Mailing lists
Makehas the following mailing lists:bug-makeis used to discuss most aspects ofMake,including development and enhancement requests, as well as bug reports.help-make isfor general user help and discussion.
Announcements aboutMakeand most other GNU software are made oninfo-gnu(archive).
Security reports that should not be made immediately public can besent directly to the maintainer.If there is no response to an urgentissue, you can escalate to the generalsecuritymailing list for advice.Getting involved
Development ofMake,and GNU in general, is a volunteer effort, and you can contribute.Forinformation, please read How to help GNU.If you'dlike to get involved, it's a good idea to join the discussion mailinglist (see above).Test releasesTrying the latest test release (when available) is alwaysappreciated.Test releases ofMakecan be found athttp://alpha.gnu.org/gnu/make/(via HTTP) andftp://alpha.gnu.org/gnu/make/(via FTP).DevelopmentFor development sources, issue trackers, and otherinformation, please see theMakeproject pageat savannah.gnu.org.TranslatingMakeTo translateMake'smessages into other languages, please see the Translation Projectpage forMake.If you have a new translation of the message strings,or updates to the existing strings, please have the changes made in thisrepository.Only translations from this site will be incorporated intoMake.For more information, see the TranslationProject.MaintainerMakeis currently being maintained byPaul Smith.Please use the mailing lists for contact.Licensing
Makeis free software; you can redistribute it and/or modify it under theterms of the GNU General Public License as published by the FreeSoftware Foundation; either version 3 of the License, or (at youroption) any later version.