[chise/xemacs-chise.git-] / info / standards.info-3

This is ../info/standards.info, produced by makeinfo version 4.0 from
standards.texi.

START-INFO-DIR-ENTRY
* Standards: (standards).        GNU coding standards.
END-INFO-DIR-ENTRY

   GNU Coding Standards Copyright (C) 1992, 1993, 1994, 1995, 1996,
1997, 1998, 1999, 2000 Free Software Foundation, Inc.

   Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided that
the entire resulting derived work is distributed under the terms of a
permission notice identical to this one.

   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be stated in a
translation approved by the Free Software Foundation.

\1f
File: standards.info,  Node: Managing Releases,  Next: References,  Prev: Documentation,  Up: Top

The Release Process
*******************

   Making a release is more than just bundling up your source files in a
tar file and putting it up for FTP.  You should set up your software so
that it can be configured to run on a variety of systems.  Your Makefile
should conform to the GNU standards described below, and your directory
layout should also conform to the standards discussed below.  Doing so
makes it easy to include your package into the larger framework of all
GNU software.

* Menu:

* Configuration::               How Configuration Should Work
* Makefile Conventions::        Makefile Conventions
* Releases::                    Making Releases

\1f
File: standards.info,  Node: Configuration,  Next: Makefile Conventions,  Up: Managing Releases

How Configuration Should Work
=============================

   Each GNU distribution should come with a shell script named
`configure'.  This script is given arguments which describe the kind of
machine and system you want to compile the program for.

   The `configure' script must record the configuration options so that
they affect compilation.

   One way to do this is to make a link from a standard name such as
`config.h' to the proper configuration file for the chosen system.  If
you use this technique, the distribution should _not_ contain a file
named `config.h'.  This is so that people won't be able to build the
program without configuring it first.

   Another thing that `configure' can do is to edit the Makefile.  If
you do this, the distribution should _not_ contain a file named
`Makefile'.  Instead, it should include a file `Makefile.in' which
contains the input used for editing.  Once again, this is so that people
won't be able to build the program without configuring it first.

   If `configure' does write the `Makefile', then `Makefile' should
have a target named `Makefile' which causes `configure' to be rerun,
setting up the same configuration that was set up last time.  The files
that `configure' reads should be listed as dependencies of `Makefile'.

   All the files which are output from the `configure' script should
have comments at the beginning explaining that they were generated
automatically using `configure'.  This is so that users won't think of
trying to edit them by hand.

   The `configure' script should write a file named `config.status'
which describes which configuration options were specified when the
program was last configured.  This file should be a shell script which,
if run, will recreate the same configuration.

   The `configure' script should accept an option of the form
`--srcdir=DIRNAME' to specify the directory where sources are found (if
it is not the current directory).  This makes it possible to build the
program in a separate directory, so that the actual source directory is
not modified.

   If the user does not specify `--srcdir', then `configure' should
check both `.' and `..' to see if it can find the sources.  If it finds
the sources in one of these places, it should use them from there.
Otherwise, it should report that it cannot find the sources, and should
exit with nonzero status.

   Usually the easy way to support `--srcdir' is by editing a
definition of `VPATH' into the Makefile.  Some rules may need to refer
explicitly to the specified source directory.  To make this possible,
`configure' can add to the Makefile a variable named `srcdir' whose
value is precisely the specified directory.

   The `configure' script should also take an argument which specifies
the type of system to build the program for.  This argument should look
like this:

     CPU-COMPANY-SYSTEM

   For example, a Sun 3 might be `m68k-sun-sunos4.1'.

   The `configure' script needs to be able to decode all plausible
alternatives for how to describe a machine.  Thus, `sun3-sunos4.1'
would be a valid alias.  For many programs, `vax-dec-ultrix' would be
an alias for `vax-dec-bsd', simply because the differences between
Ultrix and BSD are rarely noticeable, but a few programs might need to
distinguish them.

   There is a shell script called `config.sub' that you can use as a
subroutine to validate system types and canonicalize aliases.

   Other options are permitted to specify in more detail the software
or hardware present on the machine, and include or exclude optional
parts of the package:

`--enable-FEATURE[=PARAMETER]'
     Configure the package to build and install an optional user-level
     facility called FEATURE.  This allows users to choose which
     optional features to include.  Giving an optional PARAMETER of
     `no' should omit FEATURE, if it is built by default.

     No `--enable' option should *ever* cause one feature to replace
     another.  No `--enable' option should ever substitute one useful
     behavior for another useful behavior.  The only proper use for
     `--enable' is for questions of whether to build part of the program
     or exclude it.

`--with-PACKAGE'
     The package PACKAGE will be installed, so configure this package
     to work with PACKAGE.

     Possible values of PACKAGE include `gnu-as' (or `gas'), `gnu-ld',
     `gnu-libc', `gdb', `x', and `x-toolkit'.

     Do not use a `--with' option to specify the file name to use to
     find certain files.  That is outside the scope of what `--with'
     options are for.

   All `configure' scripts should accept all of these "detail" options,
whether or not they make any difference to the particular package at
hand.  In particular, they should accept any option that starts with
`--with-' or `--enable-'.  This is so users will be able to configure
an entire GNU source tree at once with a single set of options.

   You will note that the categories `--with-' and `--enable-' are
narrow: they *do not* provide a place for any sort of option you might
think of.  That is deliberate.  We want to limit the possible
configuration options in GNU software.  We do not want GNU programs to
have idiosyncratic configuration options.

   Packages that perform part of the compilation process may support
cross-compilation.  In such a case, the host and target machines for the
program may be different.

   The `configure' script should normally treat the specified type of
system as both the host and the target, thus producing a program which
works for the same type of machine that it runs on.

   To configure a cross-compiler, cross-assembler, or what have you, you
should specify a target different from the host, using the configure
option `--target=TARGETTYPE'.  The syntax for TARGETTYPE is the same as
for the host type.  So the command would look like this:

     ./configure HOSTTYPE --target=TARGETTYPE

   Programs for which cross-operation is not meaningful need not accept
the `--target' option, because configuring an entire operating system
for cross-operation is not a meaningful operation.

   Bootstrapping a cross-compiler requires compiling it on a machine
other than the host it will run on.  Compilation packages accept a
configuration option `--build=BUILDTYPE' for specifying the
configuration on which you will compile them, but the configure script
should normally guess the build machine type (using `config.guess'), so
this option is probably not necessary.  The host and target types
normally default from the build type, so in bootstrapping a
cross-compiler you must specify them both explicitly.

   Some programs have ways of configuring themselves automatically.  If
your program is set up to do this, your `configure' script can simply
ignore most of its arguments.

\1f
File: standards.info,  Node: Makefile Conventions,  Next: Releases,  Prev: Configuration,  Up: Managing Releases

Makefile Conventions
====================

   This node describes conventions for writing the Makefiles for GNU
programs.  Using Automake will help you write a Makefile that follows
these conventions.

* Menu:

* Makefile Basics::             General Conventions for Makefiles
* Utilities in Makefiles::      Utilities in Makefiles
* Command Variables::           Variables for Specifying Commands
* Directory Variables::         Variables for Installation Directories
* Standard Targets::            Standard Targets for Users
* Install Command Categories::  Three categories of commands in the `install'
                                  rule: normal, pre-install and post-install.

\1f
File: standards.info,  Node: Makefile Basics,  Next: Utilities in Makefiles,  Up: Makefile Conventions

General Conventions for Makefiles
---------------------------------

   Every Makefile should contain this line:

     SHELL = /bin/sh

to avoid trouble on systems where the `SHELL' variable might be
inherited from the environment.  (This is never a problem with GNU
`make'.)

   Different `make' programs have incompatible suffix lists and
implicit rules, and this sometimes creates confusion or misbehavior.  So
it is a good idea to set the suffix list explicitly using only the
suffixes you need in the particular Makefile, like this:

     .SUFFIXES:
     .SUFFIXES: .c .o

The first line clears out the suffix list, the second introduces all
suffixes which may be subject to implicit rules in this Makefile.

   Don't assume that `.' is in the path for command execution.  When
you need to run programs that are a part of your package during the
make, please make sure that it uses `./' if the program is built as
part of the make or `$(srcdir)/' if the file is an unchanging part of
the source code.  Without one of these prefixes, the current search
path is used.

   The distinction between `./' (the "build directory") and
`$(srcdir)/' (the "source directory") is important because users can
build in a separate directory using the `--srcdir' option to
`configure'.  A rule of the form:

     foo.1 : foo.man sedscript
             sed -e sedscript foo.man > foo.1

will fail when the build directory is not the source directory, because
`foo.man' and `sedscript' are in the source directory.

   When using GNU `make', relying on `VPATH' to find the source file
will work in the case where there is a single dependency file, since
the `make' automatic variable `$<' will represent the source file
wherever it is.  (Many versions of `make' set `$<' only in implicit
rules.)  A Makefile target like

     foo.o : bar.c
             $(CC) -I. -I$(srcdir) $(CFLAGS) -c bar.c -o foo.o

should instead be written as

     foo.o : bar.c
             $(CC) -I. -I$(srcdir) $(CFLAGS) -c $< -o $@

in order to allow `VPATH' to work correctly.  When the target has
multiple dependencies, using an explicit `$(srcdir)' is the easiest way
to make the rule work well.  For example, the target above for `foo.1'
is best written as:

     foo.1 : foo.man sedscript
             sed -e $(srcdir)/sedscript $(srcdir)/foo.man > $@

   GNU distributions usually contain some files which are not source
files--for example, Info files, and the output from Autoconf, Automake,
Bison or Flex.  Since these files normally appear in the source
directory, they should always appear in the source directory, not in the
build directory.  So Makefile rules to update them should put the
updated files in the source directory.

   However, if a file does not appear in the distribution, then the
Makefile should not put it in the source directory, because building a
program in ordinary circumstances should not modify the source directory
in any way.

   Try to make the build and installation targets, at least (and all
their subtargets) work correctly with a parallel `make'.

\1f
File: standards.info,  Node: Utilities in Makefiles,  Next: Command Variables,  Prev: Makefile Basics,  Up: Makefile Conventions

Utilities in Makefiles
----------------------

   Write the Makefile commands (and any shell scripts, such as
`configure') to run in `sh', not in `csh'.  Don't use any special
features of `ksh' or `bash'.

   The `configure' script and the Makefile rules for building and
installation should not use any utilities directly except these:

     cat cmp cp diff echo egrep expr false grep install-info
     ln ls mkdir mv pwd rm rmdir sed sleep sort tar test touch true

   The compression program `gzip' can be used in the `dist' rule.

   Stick to the generally supported options for these programs.  For
example, don't use `mkdir -p', convenient as it may be, because most
systems don't support it.

   It is a good idea to avoid creating symbolic links in makefiles,
since a few systems don't support them.

   The Makefile rules for building and installation can also use
compilers and related programs, but should do so via `make' variables
so that the user can substitute alternatives.  Here are some of the
programs we mean:

     ar bison cc flex install ld ldconfig lex
     make makeinfo ranlib texi2dvi yacc

   Use the following `make' variables to run those programs:

     $(AR) $(BISON) $(CC) $(FLEX) $(INSTALL) $(LD) $(LDCONFIG) $(LEX)
     $(MAKE) $(MAKEINFO) $(RANLIB) $(TEXI2DVI) $(YACC)

   When you use `ranlib' or `ldconfig', you should make sure nothing
bad happens if the system does not have the program in question.
Arrange to ignore an error from that command, and print a message before
the command to tell the user that failure of this command does not mean
a problem.  (The Autoconf `AC_PROG_RANLIB' macro can help with this.)

   If you use symbolic links, you should implement a fallback for
systems that don't have symbolic links.

   Additional utilities that can be used via Make variables are:

     chgrp chmod chown mknod

   It is ok to use other utilities in Makefile portions (or scripts)
intended only for particular systems where you know those utilities
exist.

\1f
File: standards.info,  Node: Command Variables,  Next: Directory Variables,  Prev: Utilities in Makefiles,  Up: Makefile Conventions

Variables for Specifying Commands
---------------------------------

   Makefiles should provide variables for overriding certain commands,
options, and so on.

   In particular, you should run most utility programs via variables.
Thus, if you use Bison, have a variable named `BISON' whose default
value is set with `BISON = bison', and refer to it with `$(BISON)'
whenever you need to use Bison.

   File management utilities such as `ln', `rm', `mv', and so on, need
not be referred to through variables in this way, since users don't
need to replace them with other programs.

   Each program-name variable should come with an options variable that
is used to supply options to the program.  Append `FLAGS' to the
program-name variable name to get the options variable name--for
example, `BISONFLAGS'.  (The names `CFLAGS' for the C compiler,
`YFLAGS' for yacc, and `LFLAGS' for lex, are exceptions to this rule,
but we keep them because they are standard.)  Use `CPPFLAGS' in any
compilation command that runs the preprocessor, and use `LDFLAGS' in
any compilation command that does linking as well as in any direct use
of `ld'.

   If there are C compiler options that _must_ be used for proper
compilation of certain files, do not include them in `CFLAGS'.  Users
expect to be able to specify `CFLAGS' freely themselves.  Instead,
arrange to pass the necessary options to the C compiler independently
of `CFLAGS', by writing them explicitly in the compilation commands or
by defining an implicit rule, like this:

     CFLAGS = -g
     ALL_CFLAGS = -I. $(CFLAGS)
     .c.o:
             $(CC) -c $(CPPFLAGS) $(ALL_CFLAGS) $<

   Do include the `-g' option in `CFLAGS', because that is not
_required_ for proper compilation.  You can consider it a default that
is only recommended.  If the package is set up so that it is compiled
with GCC by default, then you might as well include `-O' in the default
value of `CFLAGS' as well.

   Put `CFLAGS' last in the compilation command, after other variables
containing compiler options, so the user can use `CFLAGS' to override
the others.

   `CFLAGS' should be used in every invocation of the C compiler, both
those which do compilation and those which do linking.

   Every Makefile should define the variable `INSTALL', which is the
basic command for installing a file into the system.

   Every Makefile should also define the variables `INSTALL_PROGRAM'
and `INSTALL_DATA'.  (The default for `INSTALL_PROGRAM' should be
`$(INSTALL)'; the default for `INSTALL_DATA' should be `${INSTALL} -m
644'.)  Then it should use those variables as the commands for actual
installation, for executables and nonexecutables respectively.  Use
these variables as follows:

     $(INSTALL_PROGRAM) foo $(bindir)/foo
     $(INSTALL_DATA) libfoo.a $(libdir)/libfoo.a

   Optionally, you may prepend the value of `DESTDIR' to the target
filename.  Doing this allows the installer to create a snapshot of the
installation to be copied onto the real target filesystem later.  Do not
set the value of `DESTDIR' in your Makefile, and do not include it in
any installed files.  With support for `DESTDIR', the above examples
become:

     $(INSTALL_PROGRAM) foo $(DESTDIR)$(bindir)/foo
     $(INSTALL_DATA) libfoo.a $(DESTDIR)$(libdir)/libfoo.a

Always use a file name, not a directory name, as the second argument of
the installation commands.  Use a separate command for each file to be
installed.

\1f
File: standards.info,  Node: Directory Variables,  Next: Standard Targets,  Prev: Command Variables,  Up: Makefile Conventions

Variables for Installation Directories
--------------------------------------

   Installation directories should always be named by variables, so it
is easy to install in a nonstandard place.  The standard names for these
variables are described below.  They are based on a standard filesystem
layout; variants of it are used in SVR4, 4.4BSD, GNU/Linux, Ultrix v4,
and other modern operating systems.

   These two variables set the root for the installation.  All the other
installation directories should be subdirectories of one of these two,
and nothing should be directly installed into these two directories.

`prefix'
     A prefix used in constructing the default values of the variables
     listed below.  The default value of `prefix' should be
     `/usr/local'.  When building the complete GNU system, the prefix
     will be empty and `/usr' will be a symbolic link to `/'.  (If you
     are using Autoconf, write it as `@prefix@'.)

     Running `make install' with a different value of `prefix' from the
     one used to build the program should _not_ recompile the program.

`exec_prefix'
     A prefix used in constructing the default values of some of the
     variables listed below.  The default value of `exec_prefix' should
     be `$(prefix)'.  (If you are using Autoconf, write it as
     `@exec_prefix@'.)

     Generally, `$(exec_prefix)' is used for directories that contain
     machine-specific files (such as executables and subroutine
     libraries), while `$(prefix)' is used directly for other
     directories.

     Running `make install' with a different value of `exec_prefix'
     from the one used to build the program should _not_ recompile the
     program.

   Executable programs are installed in one of the following
directories.

`bindir'
     The directory for installing executable programs that users can
     run.  This should normally be `/usr/local/bin', but write it as
     `$(exec_prefix)/bin'.  (If you are using Autoconf, write it as
     `@bindir@'.)

`sbindir'
     The directory for installing executable programs that can be run
     from the shell, but are only generally useful to system
     administrators.  This should normally be `/usr/local/sbin', but
     write it as `$(exec_prefix)/sbin'.  (If you are using Autoconf,
     write it as `@sbindir@'.)

`libexecdir'
     The directory for installing executable programs to be run by other
     programs rather than by users.  This directory should normally be
     `/usr/local/libexec', but write it as `$(exec_prefix)/libexec'.
     (If you are using Autoconf, write it as `@libexecdir@'.)

   Data files used by the program during its execution are divided into
categories in two ways.

   * Some files are normally modified by programs; others are never
     normally modified (though users may edit some of these).

   * Some files are architecture-independent and can be shared by all
     machines at a site; some are architecture-dependent and can be
     shared only by machines of the same kind and operating system;
     others may never be shared between two machines.

   This makes for six different possibilities.  However, we want to
discourage the use of architecture-dependent files, aside from object
files and libraries.  It is much cleaner to make other data files
architecture-independent, and it is generally not hard.

   Therefore, here are the variables Makefiles should use to specify
directories:

`datadir'
     The directory for installing read-only architecture independent
     data files.  This should normally be `/usr/local/share', but write
     it as `$(prefix)/share'.  (If you are using Autoconf, write it as
     `@datadir@'.)  As a special exception, see `$(infodir)' and
     `$(includedir)' below.

`sysconfdir'
     The directory for installing read-only data files that pertain to a
     single machine-that is to say, files for configuring a host.
     Mailer and network configuration files, `/etc/passwd', and so
     forth belong here.  All the files in this directory should be
     ordinary ASCII text files.  This directory should normally be
     `/usr/local/etc', but write it as `$(prefix)/etc'.  (If you are
     using Autoconf, write it as `@sysconfdir@'.)

     Do not install executables here in this directory (they probably
     belong in `$(libexecdir)' or `$(sbindir)').  Also do not install
     files that are modified in the normal course of their use (programs
     whose purpose is to change the configuration of the system
     excluded).  Those probably belong in `$(localstatedir)'.

`sharedstatedir'
     The directory for installing architecture-independent data files
     which the programs modify while they run.  This should normally be
     `/usr/local/com', but write it as `$(prefix)/com'.  (If you are
     using Autoconf, write it as `@sharedstatedir@'.)

`localstatedir'
     The directory for installing data files which the programs modify
     while they run, and that pertain to one specific machine.  Users
     should never need to modify files in this directory to configure
     the package's operation; put such configuration information in
     separate files that go in `$(datadir)' or `$(sysconfdir)'.
     `$(localstatedir)' should normally be `/usr/local/var', but write
     it as `$(prefix)/var'.  (If you are using Autoconf, write it as
     `@localstatedir@'.)

`libdir'
     The directory for object files and libraries of object code.  Do
     not install executables here, they probably ought to go in
     `$(libexecdir)' instead.  The value of `libdir' should normally be
     `/usr/local/lib', but write it as `$(exec_prefix)/lib'.  (If you
     are using Autoconf, write it as `@libdir@'.)

`infodir'
     The directory for installing the Info files for this package.  By
     default, it should be `/usr/local/info', but it should be written
     as `$(prefix)/info'.  (If you are using Autoconf, write it as
     `@infodir@'.)

`lispdir'
     The directory for installing any Emacs Lisp files in this package.
     By default, it should be `/usr/local/share/emacs/site-lisp', but
     it should be written as `$(prefix)/share/emacs/site-lisp'.

     If you are using Autoconf, write the default as `@lispdir@'.  In
     order to make `@lispdir@' work, you need the following lines in
     your `configure.in' file:

          lispdir='${datadir}/emacs/site-lisp'
          AC_SUBST(lispdir)

`includedir'
     The directory for installing header files to be included by user
     programs with the C `#include' preprocessor directive.  This
     should normally be `/usr/local/include', but write it as
     `$(prefix)/include'.  (If you are using Autoconf, write it as
     `@includedir@'.)

     Most compilers other than GCC do not look for header files in
     directory `/usr/local/include'.  So installing the header files
     this way is only useful with GCC.  Sometimes this is not a problem
     because some libraries are only really intended to work with GCC.
     But some libraries are intended to work with other compilers.
     They should install their header files in two places, one
     specified by `includedir' and one specified by `oldincludedir'.

`oldincludedir'
     The directory for installing `#include' header files for use with
     compilers other than GCC.  This should normally be `/usr/include'.
     (If you are using Autoconf, you can write it as `@oldincludedir@'.)

     The Makefile commands should check whether the value of
     `oldincludedir' is empty.  If it is, they should not try to use
     it; they should cancel the second installation of the header files.

     A package should not replace an existing header in this directory
     unless the header came from the same package.  Thus, if your Foo
     package provides a header file `foo.h', then it should install the
     header file in the `oldincludedir' directory if either (1) there
     is no `foo.h' there or (2) the `foo.h' that exists came from the
     Foo package.

     To tell whether `foo.h' came from the Foo package, put a magic
     string in the file--part of a comment--and `grep' for that string.

   Unix-style man pages are installed in one of the following:

`mandir'
     The top-level directory for installing the man pages (if any) for
     this package.  It will normally be `/usr/local/man', but you should
     write it as `$(prefix)/man'.  (If you are using Autoconf, write it
     as `@mandir@'.)

`man1dir'
     The directory for installing section 1 man pages.  Write it as
     `$(mandir)/man1'.

`man2dir'
     The directory for installing section 2 man pages.  Write it as
     `$(mandir)/man2'

`...'
     *Don't make the primary documentation for any GNU software be a
     man page.  Write a manual in Texinfo instead.  Man pages are just
     for the sake of people running GNU software on Unix, which is a
     secondary application only.*

`manext'
     The file name extension for the installed man page.  This should
     contain a period followed by the appropriate digit; it should
     normally be `.1'.

`man1ext'
     The file name extension for installed section 1 man pages.

`man2ext'
     The file name extension for installed section 2 man pages.

`...'
     Use these names instead of `manext' if the package needs to
     install man pages in more than one section of the manual.

   And finally, you should set the following variable:

`srcdir'
     The directory for the sources being compiled.  The value of this
     variable is normally inserted by the `configure' shell script.
     (If you are using Autconf, use `srcdir = @srcdir@'.)

   For example:

     # Common prefix for installation directories.
     # NOTE: This directory must exist when you start the install.
     prefix = /usr/local
     exec_prefix = $(prefix)
     # Where to put the executable for the command `gcc'.
     bindir = $(exec_prefix)/bin
     # Where to put the directories used by the compiler.
     libexecdir = $(exec_prefix)/libexec
     # Where to put the Info files.
     infodir = $(prefix)/info

   If your program installs a large number of files into one of the
standard user-specified directories, it might be useful to group them
into a subdirectory particular to that program.  If you do this, you
should write the `install' rule to create these subdirectories.

   Do not expect the user to include the subdirectory name in the value
of any of the variables listed above.  The idea of having a uniform set
of variable names for installation directories is to enable the user to
specify the exact same values for several different GNU packages.  In
order for this to be useful, all the packages must be designed so that
they will work sensibly when the user does so.

\1f
File: standards.info,  Node: Standard Targets,  Next: Install Command Categories,  Prev: Directory Variables,  Up: Makefile Conventions

Standard Targets for Users
--------------------------

   All GNU programs should have the following targets in their
Makefiles:

`all'
     Compile the entire program.  This should be the default target.
     This target need not rebuild any documentation files; Info files
     should normally be included in the distribution, and DVI files
     should be made only when explicitly asked for.

     By default, the Make rules should compile and link with `-g', so
     that executable programs have debugging symbols.  Users who don't
     mind being helpless can strip the executables later if they wish.

`install'
     Compile the program and copy the executables, libraries, and so on
     to the file names where they should reside for actual use.  If
     there is a simple test to verify that a program is properly
     installed, this target should run that test.

     Do not strip executables when installing them.  Devil-may-care
     users can use the `install-strip' target to do that.

     If possible, write the `install' target rule so that it does not
     modify anything in the directory where the program was built,
     provided `make all' has just been done.  This is convenient for
     building the program under one user name and installing it under
     another.

     The commands should create all the directories in which files are
     to be installed, if they don't already exist.  This includes the
     directories specified as the values of the variables `prefix' and
     `exec_prefix', as well as all subdirectories that are needed.  One
     way to do this is by means of an `installdirs' target as described
     below.

     Use `-' before any command for installing a man page, so that
     `make' will ignore any errors.  This is in case there are systems
     that don't have the Unix man page documentation system installed.

     The way to install Info files is to copy them into `$(infodir)'
     with `$(INSTALL_DATA)' (*note Command Variables::), and then run
     the `install-info' program if it is present.  `install-info' is a
     program that edits the Info `dir' file to add or update the menu
     entry for the given Info file; it is part of the Texinfo package.
     Here is a sample rule to install an Info file:

          $(DESTDIR)$(infodir)/foo.info: foo.info
                  $(POST_INSTALL)
          # There may be a newer info file in . than in srcdir.
                  -if test -f foo.info; then d=.; \
                   else d=$(srcdir); fi; \
                  $(INSTALL_DATA) $$d/foo.info $(DESTDIR)$@; \
          # Run install-info only if it exists.
          # Use `if' instead of just prepending `-' to the
          # line so we notice real errors from install-info.
          # We use `$(SHELL) -c' because some shells do not
          # fail gracefully when there is an unknown command.
                  if $(SHELL) -c 'install-info --version' \
                     >/dev/null 2>&1; then \
                    install-info --dir-file=$(DESTDIR)$(infodir)/dir \
                                 $(DESTDIR)$(infodir)/foo.info; \
                  else true; fi

     When writing the `install' target, you must classify all the
     commands into three categories: normal ones, "pre-installation"
     commands and "post-installation" commands.  *Note Install Command
     Categories::.

`uninstall'
     Delete all the installed files--the copies that the `install'
     target creates.

     This rule should not modify the directories where compilation is
     done, only the directories where files are installed.

     The uninstallation commands are divided into three categories,
     just like the installation commands.  *Note Install Command
     Categories::.

`install-strip'
     Like `install', but strip the executable files while installing
     them.  In simple cases, this target can use the `install' target in
     a simple way:

          install-strip:
                  $(MAKE) INSTALL_PROGRAM='$(INSTALL_PROGRAM) -s' \
                          install

     But if the package installs scripts as well as real executables,
     the `install-strip' target can't just refer to the `install'
     target; it has to strip the executables but not the scripts.

     `install-strip' should not strip the executables in the build
     directory which are being copied for installation.  It should only
     strip the copies that are installed.

     Normally we do not recommend stripping an executable unless you
     are sure the program has no bugs.  However, it can be reasonable
     to install a stripped executable for actual execution while saving
     the unstripped executable elsewhere in case there is a bug.

`clean'
     Delete all files from the current directory that are normally
     created by building the program.  Don't delete the files that
     record the configuration.  Also preserve files that could be made
     by building, but normally aren't because the distribution comes
     with them.

     Delete `.dvi' files here if they are not part of the distribution.

`distclean'
     Delete all files from the current directory that are created by
     configuring or building the program.  If you have unpacked the
     source and built the program without creating any other files,
     `make distclean' should leave only the files that were in the
     distribution.

`mostlyclean'
     Like `clean', but may refrain from deleting a few files that people
     normally don't want to recompile.  For example, the `mostlyclean'
     target for GCC does not delete `libgcc.a', because recompiling it
     is rarely necessary and takes a lot of time.

`maintainer-clean'
     Delete almost everything from the current directory that can be
     reconstructed with this Makefile.  This typically includes
     everything deleted by `distclean', plus more: C source files
     produced by Bison, tags tables, Info files, and so on.

     The reason we say "almost everything" is that running the command
     `make maintainer-clean' should not delete `configure' even if
     `configure' can be remade using a rule in the Makefile.  More
     generally, `make maintainer-clean' should not delete anything that
     needs to exist in order to run `configure' and then begin to build
     the program.  This is the only exception; `maintainer-clean' should
     delete everything else that can be rebuilt.

     The `maintainer-clean' target is intended to be used by a
     maintainer of the package, not by ordinary users.  You may need
     special tools to reconstruct some of the files that `make
     maintainer-clean' deletes.  Since these files are normally
     included in the distribution, we don't take care to make them easy
     to reconstruct.  If you find you need to unpack the full
     distribution again, don't blame us.

     To help make users aware of this, the commands for the special
     `maintainer-clean' target should start with these two:

          @echo 'This command is intended for maintainers to use; it'
          @echo 'deletes files that may need special tools to rebuild.'

`TAGS'
     Update a tags table for this program.

`info'
     Generate any Info files needed.  The best way to write the rules
     is as follows:

          info: foo.info
          
          foo.info: foo.texi chap1.texi chap2.texi
                  $(MAKEINFO) $(srcdir)/foo.texi

     You must define the variable `MAKEINFO' in the Makefile.  It should
     run the `makeinfo' program, which is part of the Texinfo
     distribution.

     Normally a GNU distribution comes with Info files, and that means
     the Info files are present in the source directory.  Therefore,
     the Make rule for an info file should update it in the source
     directory.  When users build the package, ordinarily Make will not
     update the Info files because they will already be up to date.

`dvi'
     Generate DVI files for all Texinfo documentation.  For example:

          dvi: foo.dvi
          
          foo.dvi: foo.texi chap1.texi chap2.texi
                  $(TEXI2DVI) $(srcdir)/foo.texi

     You must define the variable `TEXI2DVI' in the Makefile.  It should
     run the program `texi2dvi', which is part of the Texinfo
     distribution.(1)  Alternatively, write just the dependencies, and
     allow GNU `make' to provide the command.

`dist'
     Create a distribution tar file for this program.  The tar file
     should be set up so that the file names in the tar file start with
     a subdirectory name which is the name of the package it is a
     distribution for.  This name can include the version number.

     For example, the distribution tar file of GCC version 1.40 unpacks
     into a subdirectory named `gcc-1.40'.

     The easiest way to do this is to create a subdirectory
     appropriately named, use `ln' or `cp' to install the proper files
     in it, and then `tar' that subdirectory.

     Compress the tar file with `gzip'.  For example, the actual
     distribution file for GCC version 1.40 is called `gcc-1.40.tar.gz'.

     The `dist' target should explicitly depend on all non-source files
     that are in the distribution, to make sure they are up to date in
     the distribution.  *Note Making Releases: Releases.

`check'
     Perform self-tests (if any).  The user must build the program
     before running the tests, but need not install the program; you
     should write the self-tests so that they work when the program is
     built but not installed.

   The following targets are suggested as conventional names, for
programs in which they are useful.

`installcheck'
     Perform installation tests (if any).  The user must build and
     install the program before running the tests.  You should not
     assume that `$(bindir)' is in the search path.

`installdirs'
     It's useful to add a target named `installdirs' to create the
     directories where files are installed, and their parent
     directories.  There is a script called `mkinstalldirs' which is
     convenient for this; you can find it in the Texinfo package.  You
     can use a rule like this:

          # Make sure all installation directories (e.g. $(bindir))
          # actually exist by making them if necessary.
          installdirs: mkinstalldirs
                  $(srcdir)/mkinstalldirs $(bindir) $(datadir) \
                                          $(libdir) $(infodir) \
                                          $(mandir)

     or, if you wish to support `DESTDIR',

          # Make sure all installation directories (e.g. $(bindir))
          # actually exist by making them if necessary.
          installdirs: mkinstalldirs
                  $(srcdir)/mkinstalldirs \
                      $(DESTDIR)$(bindir) $(DESTDIR)$(datadir) \
                      $(DESTDIR)$(libdir) $(DESTDIR)$(infodir) \
                      $(DESTDIR)$(mandir)

     This rule should not modify the directories where compilation is
     done.  It should do nothing but create installation directories.

   ---------- Footnotes ----------

   (1) `texi2dvi' uses TeX to do the real work of formatting. TeX is
not distributed with Texinfo.

\1f
File: standards.info,  Node: Install Command Categories,  Prev: Standard Targets,  Up: Makefile Conventions

Install Command Categories
--------------------------

   When writing the `install' target, you must classify all the
commands into three categories: normal ones, "pre-installation"
commands and "post-installation" commands.

   Normal commands move files into their proper places, and set their
modes.  They may not alter any files except the ones that come entirely
from the package they belong to.

   Pre-installation and post-installation commands may alter other
files; in particular, they can edit global configuration files or data
bases.

   Pre-installation commands are typically executed before the normal
commands, and post-installation commands are typically run after the
normal commands.

   The most common use for a post-installation command is to run
`install-info'.  This cannot be done with a normal command, since it
alters a file (the Info directory) which does not come entirely and
solely from the package being installed.  It is a post-installation
command because it needs to be done after the normal command which
installs the package's Info files.

   Most programs don't need any pre-installation commands, but we have
the feature just in case it is needed.

   To classify the commands in the `install' rule into these three
categories, insert "category lines" among them.  A category line
specifies the category for the commands that follow.

   A category line consists of a tab and a reference to a special Make
variable, plus an optional comment at the end.  There are three
variables you can use, one for each category; the variable name
specifies the category.  Category lines are no-ops in ordinary execution
because these three Make variables are normally undefined (and you
_should not_ define them in the makefile).

   Here are the three possible category lines, each with a comment that
explains what it means:

             $(PRE_INSTALL)     # Pre-install commands follow.
             $(POST_INSTALL)    # Post-install commands follow.
             $(NORMAL_INSTALL)  # Normal commands follow.

   If you don't use a category line at the beginning of the `install'
rule, all the commands are classified as normal until the first category
line.  If you don't use any category lines, all the commands are
classified as normal.

   These are the category lines for `uninstall':

             $(PRE_UNINSTALL)     # Pre-uninstall commands follow.
             $(POST_UNINSTALL)    # Post-uninstall commands follow.
             $(NORMAL_UNINSTALL)  # Normal commands follow.

   Typically, a pre-uninstall command would be used for deleting entries
from the Info directory.

   If the `install' or `uninstall' target has any dependencies which
act as subroutines of installation, then you should start _each_
dependency's commands with a category line, and start the main target's
commands with a category line also.  This way, you can ensure that each
command is placed in the right category regardless of which of the
dependencies actually run.

   Pre-installation and post-installation commands should not run any
programs except for these:

     [ basename bash cat chgrp chmod chown cmp cp dd diff echo
     egrep expand expr false fgrep find getopt grep gunzip gzip
     hostname install install-info kill ldconfig ln ls md5sum
     mkdir mkfifo mknod mv printenv pwd rm rmdir sed sort tee
     test touch true uname xargs yes

   The reason for distinguishing the commands in this way is for the
sake of making binary packages.  Typically a binary package contains
all the executables and other files that need to be installed, and has
its own method of installing them--so it does not need to run the normal
installation commands.  But installing the binary package does need to
execute the pre-installation and post-installation commands.

   Programs to build binary packages work by extracting the
pre-installation and post-installation commands.  Here is one way of
extracting the pre-installation commands:

     make -n install -o all \
           PRE_INSTALL=pre-install \
           POST_INSTALL=post-install \
           NORMAL_INSTALL=normal-install \
       | gawk -f pre-install.awk

where the file `pre-install.awk' could contain this:

     $0 ~ /^\t[ \t]*(normal_install|post_install)[ \t]*$/ {on = 0}
     on {print $0}
     $0 ~ /^\t[ \t]*pre_install[ \t]*$/ {on = 1}

   The resulting file of pre-installation commands is executed as a
shell script as part of installing the binary package.

\1f
File: standards.info,  Node: Releases,  Prev: Makefile Conventions,  Up: Managing Releases

Making Releases
===============

   Package the distribution of `Foo version 69.96' up in a gzipped tar
file with the name `foo-69.96.tar.gz'.  It should unpack into a
subdirectory named `foo-69.96'.

   Building and installing the program should never modify any of the
files contained in the distribution.  This means that all the files
that form part of the program in any way must be classified into "source
files" and "non-source files".  Source files are written by humans and
never changed automatically; non-source files are produced from source
files by programs under the control of the Makefile.

   The distribution should contain a file named `README' which gives
the name of the package, and a general description of what it does.  It
is also good to explain the purpose of each of the first-level
subdirectories in the package, if there are any.  The `README' file
should either state the version number of the package, or refer to where
in the package it can be found.

   The `README' file should refer to the file `INSTALL', which should
contain an explanation of the installation procedure.

   The `README' file should also refer to the file which contains the
copying conditions.  The GNU GPL, if used, should be in a file called
`COPYING'.  If the GNU LGPL is used, it should be in a file called
`COPYING.LIB'.

   Naturally, all the source files must be in the distribution.  It is
okay to include non-source files in the distribution, provided they are
up-to-date and machine-independent, so that building the distribution
normally will never modify them.  We commonly include non-source files
produced by Bison, `lex', TeX, and `makeinfo'; this helps avoid
unnecessary dependencies between our distributions, so that users can
install whichever packages they want to install.

   Non-source files that might actually be modified by building and
installing the program should *never* be included in the distribution.
So if you do distribute non-source files, always make sure they are up
to date when you make a new distribution.

   Make sure that the directory into which the distribution unpacks (as
well as any subdirectories) are all world-writable (octal mode 777).
This is so that old versions of `tar' which preserve the ownership and
permissions of the files from the tar archive will be able to extract
all the files even if the user is unprivileged.

   Make sure that all the files in the distribution are world-readable.

   Make sure that no file name in the distribution is more than 14
characters long.  Likewise, no file created by building the program
should have a name longer than 14 characters.  The reason for this is
that some systems adhere to a foolish interpretation of the POSIX
standard, and refuse to open a longer name, rather than truncating as
they did in the past.

   Don't include any symbolic links in the distribution itself.  If the
tar file contains symbolic links, then people cannot even unpack it on
systems that don't support symbolic links.  Also, don't use multiple
names for one file in different directories, because certain file
systems cannot handle this and that prevents unpacking the distribution.

   Try to make sure that all the file names will be unique on MS-DOS.  A
name on MS-DOS consists of up to 8 characters, optionally followed by a
period and up to three characters.  MS-DOS will truncate extra
characters both before and after the period.  Thus, `foobarhacker.c'
and `foobarhacker.o' are not ambiguous; they are truncated to
`foobarha.c' and `foobarha.o', which are distinct.

   Include in your distribution a copy of the `texinfo.tex' you used to
test print any `*.texinfo' or `*.texi' files.

   Likewise, if your program uses small GNU software packages like
regex, getopt, obstack, or termcap, include them in the distribution
file.  Leaving them out would make the distribution file a little
smaller at the expense of possible inconvenience to a user who doesn't
know what other files to get.

\1f
File: standards.info,  Node: References,  Next: Index,  Prev: Managing Releases,  Up: Top

References to Non-Free Software and Documentation
*************************************************

   A GNU program should not recommend use of any non-free program.  We
can't stop some people from writing proprietary programs, or stop other
people from using them.  But we can and should avoid helping to
advertise them to new customers.

   Sometimes it is important to mention how to build your package on
top of some non-free operating system or other non-free base package.
In such cases, please mention the name of the non-free package or
system in the briefest possible way.  Don't include any references for
where to find more information about the proprietary program.  The goal
should be that people already using the proprietary program will get
the advice they need about how to use your free program, while people
who don't already use the proprietary program will not see anything to
encourage them to take an interest in it.

   Likewise, a GNU package should not refer the user to any non-free
documentation for free software.  The need for free documentation to go
with free software is now a major focus of the GNU project; to show that
we are serious about the need for free documentation, we must not
undermine our position by recommending use of documentation that isn't
free.