diff options
Diffstat (limited to 'doc/make-stds.texi')
| -rw-r--r-- | doc/make-stds.texi | 944 |
1 files changed, 944 insertions, 0 deletions
diff --git a/doc/make-stds.texi b/doc/make-stds.texi new file mode 100644 index 0000000..68faa8d --- /dev/null +++ b/doc/make-stds.texi @@ -0,0 +1,944 @@ +@comment This file is included by both standards.texi and make.texinfo. +@comment It was broken out of standards.texi on 1/6/93 by roland. + +@node Makefile Conventions +@chapter Makefile Conventions +@comment standards.texi does not print an index, but make.texinfo does. +@cindex makefile, conventions for +@cindex conventions for makefiles +@cindex standards for makefiles + +This +@ifinfo +node +@end ifinfo +@iftex +@ifset CODESTD +section +@end ifset +@ifclear CODESTD +chapter +@end ifclear +@end iftex +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. +@end menu + +@node Makefile Basics +@section General Conventions for Makefiles + +Every Makefile should contain this line: + +@example +SHELL = /bin/sh +@end example + +@noindent +to avoid trouble on systems where the @code{SHELL} variable might be +inherited from the environment. (This is never a problem with GNU +@code{make}.) + +Different @code{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: + +@example +.SUFFIXES: +.SUFFIXES: .c .o +@end example + +@noindent +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 @file{.} 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 @file{./} if the program is built as +part of the make or @file{$(srcdir)/} if the file is an unchanging part +of the source code. Without one of these prefixes, the current search +path is used. + +The distinction between @file{./} (the @dfn{build directory}) and +@file{$(srcdir)/} (the @dfn{source directory}) is important because +users can build in a separate directory using the @samp{--srcdir} option +to @file{configure}. A rule of the form: + +@smallexample +foo.1 : foo.man sedscript + sed -e sedscript foo.man > foo.1 +@end smallexample + +@noindent +will fail when the build directory is not the source directory, because +@file{foo.man} and @file{sedscript} are in the source directory. + +When using GNU @code{make}, relying on @samp{VPATH} to find the source +file will work in the case where there is a single dependency file, +since the @code{make} automatic variable @samp{$<} will represent the +source file wherever it is. (Many versions of @code{make} set @samp{$<} +only in implicit rules.) A Makefile target like + +@smallexample +foo.o : bar.c + $(CC) -I. -I$(srcdir) $(CFLAGS) -c bar.c -o foo.o +@end smallexample + +@noindent +should instead be written as + +@smallexample +foo.o : bar.c + $(CC) -I. -I$(srcdir) $(CFLAGS) -c $< -o $@@ +@end smallexample + +@noindent +in order to allow @samp{VPATH} to work correctly. When the target has +multiple dependencies, using an explicit @samp{$(srcdir)} is the easiest +way to make the rule work well. For example, the target above for +@file{foo.1} is best written as: + +@smallexample +foo.1 : foo.man sedscript + sed -e $(srcdir)/sedscript $(srcdir)/foo.man > $@@ +@end smallexample + +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 @code{make}. + +@node Utilities in Makefiles +@section Utilities in Makefiles + +Write the Makefile commands (and any shell scripts, such as +@code{configure}) to run in @code{sh}, not in @code{csh}. Don't use any +special features of @code{ksh} or @code{bash}. + +The @code{configure} script and the Makefile rules for building and +installation should not use any utilities directly except these: + +@c dd find +@c gunzip gzip md5sum +@c mkfifo mknod tee uname + +@example +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 +@end example + +The compression program @code{gzip} can be used in the @code{dist} rule. + +Stick to the generally supported options for these programs. For +example, don't use @samp{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 @code{make} variables so that the +user can substitute alternatives. Here are some of the programs we +mean: + +@example +ar bison cc flex install ld ldconfig lex +make makeinfo ranlib texi2dvi yacc +@end example + +Use the following @code{make} variables to run those programs: + +@example +$(AR) $(BISON) $(CC) $(FLEX) $(INSTALL) $(LD) $(LDCONFIG) $(LEX) +$(MAKE) $(MAKEINFO) $(RANLIB) $(TEXI2DVI) $(YACC) +@end example + +When you use @code{ranlib} or @code{ldconfig}, you should make sure +nothing bad happens if the system does not have the program in question. +Arrange to ignore an error from that command, and print a message before +the command to tell the user that failure of this command does not mean +a problem. (The Autoconf @samp{AC_PROG_RANLIB} macro can help with +this.) + +If you use symbolic links, you should implement a fallback for systems +that don't have symbolic links. + +Additional utilities that can be used via Make variables are: + +@example +chgrp chmod chown mknod +@end example + +It is ok to use other utilities in Makefile portions (or scripts) +intended only for particular systems where you know those utilities +exist. + +@node Command Variables +@section Variables for Specifying Commands + +Makefiles should provide variables for overriding certain commands, options, +and so on. + +In particular, you should run most utility programs via variables. +Thus, if you use Bison, have a variable named @code{BISON} whose default +value is set with @samp{BISON = bison}, and refer to it with +@code{$(BISON)} whenever you need to use Bison. + +File management utilities such as @code{ln}, @code{rm}, @code{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 @samp{FLAGS} to the +program-name variable name to get the options variable name---for +example, @code{BISONFLAGS}. (The names @code{CFLAGS} for the C +compiler, @code{YFLAGS} for yacc, and @code{LFLAGS} for lex, are +exceptions to this rule, but we keep them because they are standard.) +Use @code{CPPFLAGS} in any compilation command that runs the +preprocessor, and use @code{LDFLAGS} in any compilation command that +does linking as well as in any direct use of @code{ld}. + +If there are C compiler options that @emph{must} be used for proper +compilation of certain files, do not include them in @code{CFLAGS}. +Users expect to be able to specify @code{CFLAGS} freely themselves. +Instead, arrange to pass the necessary options to the C compiler +independently of @code{CFLAGS}, by writing them explicitly in the +compilation commands or by defining an implicit rule, like this: + +@smallexample +CFLAGS = -g +ALL_CFLAGS = -I. $(CFLAGS) +.c.o: + $(CC) -c $(CPPFLAGS) $(ALL_CFLAGS) $< +@end smallexample + +Do include the @samp{-g} option in @code{CFLAGS}, because that is not +@emph{required} for proper compilation. You can consider it a default +that is only recommended. If the package is set up so that it is +compiled with GCC by default, then you might as well include @samp{-O} +in the default value of @code{CFLAGS} as well. + +Put @code{CFLAGS} last in the compilation command, after other variables +containing compiler options, so the user can use @code{CFLAGS} to +override the others. + +@code{CFLAGS} should be used in every invocation of the C compiler, +both those which do compilation and those which do linking. + +Every Makefile should define the variable @code{INSTALL}, which is the +basic command for installing a file into the system. + +Every Makefile should also define the variables @code{INSTALL_PROGRAM} +and @code{INSTALL_DATA}. (The default for @code{INSTALL_PROGRAM} should +be @code{$(INSTALL)}; the default for @code{INSTALL_DATA} should be +@code{$@{INSTALL@} -m 644}.) Then it should use those variables as the +commands for actual installation, for executables and nonexecutables +respectively. Use these variables as follows: + +@example +$(INSTALL_PROGRAM) foo $(bindir)/foo +$(INSTALL_DATA) libfoo.a $(libdir)/libfoo.a +@end example + +Optionally, you may prepend the value of @code{DESTDIR} to the target +filename. Doing this allows the installer to create a snapshot of the +installation to be copied onto the real target filesystem later. Do not +set the value of @code{DESTDIR} in your Makefile, and do not include it +in any installed files. With support for @code{DESTDIR}, the above +examples become: + +@example +$(INSTALL_PROGRAM) foo $(DESTDIR)$(bindir)/foo +$(INSTALL_DATA) libfoo.a $(DESTDIR)$(libdir)/libfoo.a +@end example + +@noindent +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. + +@node Directory Variables +@section 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. + +@table @code +@item prefix +@vindex prefix +A prefix used in constructing the default values of the variables listed +below. The default value of @code{prefix} should be @file{/usr/local}. +When building the complete GNU system, the prefix will be empty and +@file{/usr} will be a symbolic link to @file{/}. +(If you are using Autoconf, write it as @samp{@@prefix@@}.) + +Running @samp{make install} with a different value of @code{prefix} from +the one used to build the program should @emph{not} recompile the +program. + +@item exec_prefix +@vindex exec_prefix +A prefix used in constructing the default values of some of the +variables listed below. The default value of @code{exec_prefix} should +be @code{$(prefix)}. +(If you are using Autoconf, write it as @samp{@@exec_prefix@@}.) + +Generally, @code{$(exec_prefix)} is used for directories that contain +machine-specific files (such as executables and subroutine libraries), +while @code{$(prefix)} is used directly for other directories. + +Running @samp{make install} with a different value of @code{exec_prefix} +from the one used to build the program should @emph{not} recompile the +program. +@end table + +Executable programs are installed in one of the following directories. + +@table @code +@item bindir +@vindex bindir +The directory for installing executable programs that users can run. +This should normally be @file{/usr/local/bin}, but write it as +@file{$(exec_prefix)/bin}. +(If you are using Autoconf, write it as @samp{@@bindir@@}.) + +@item sbindir +@vindex 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 @file{/usr/local/sbin}, but write it as +@file{$(exec_prefix)/sbin}. +(If you are using Autoconf, write it as @samp{@@sbindir@@}.) + +@item libexecdir +@vindex libexecdir +@comment This paragraph adjusted to avoid overfull hbox --roland 5jul94 +The directory for installing executable programs to be run by other +programs rather than by users. This directory should normally be +@file{/usr/local/libexec}, but write it as @file{$(exec_prefix)/libexec}. +(If you are using Autoconf, write it as @samp{@@libexecdir@@}.) +@end table + +Data files used by the program during its execution are divided into +categories in two ways. + +@itemize @bullet +@item +Some files are normally modified by programs; others are never normally +modified (though users may edit some of these). + +@item +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. +@end itemize + +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: + +@table @samp +@item datadir +The directory for installing read-only architecture independent data +files. This should normally be @file{/usr/local/share}, but write it as +@file{$(prefix)/share}. +(If you are using Autoconf, write it as @samp{@@datadir@@}.) +As a special exception, see @file{$(infodir)} +and @file{$(includedir)} below. + +@item sysconfdir +The directory for installing read-only data files that pertain to a +single machine--that is to say, files for configuring a host. Mailer +and network configuration files, @file{/etc/passwd}, and so forth belong +here. All the files in this directory should be ordinary ASCII text +files. This directory should normally be @file{/usr/local/etc}, but +write it as @file{$(prefix)/etc}. +(If you are using Autoconf, write it as @samp{@@sysconfdir@@}.) + +Do not install executables here in this directory (they probably belong +in @file{$(libexecdir)} or @file{$(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 @file{$(localstatedir)}. + +@item sharedstatedir +The directory for installing architecture-independent data files which +the programs modify while they run. This should normally be +@file{/usr/local/com}, but write it as @file{$(prefix)/com}. +(If you are using Autoconf, write it as @samp{@@sharedstatedir@@}.) + +@item 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 @file{$(datadir)} or @file{$(sysconfdir)}. @file{$(localstatedir)} +should normally be @file{/usr/local/var}, but write it as +@file{$(prefix)/var}. +(If you are using Autoconf, write it as @samp{@@localstatedir@@}.) + +@item libdir +The directory for object files and libraries of object code. Do not +install executables here, they probably ought to go in @file{$(libexecdir)} +instead. The value of @code{libdir} should normally be +@file{/usr/local/lib}, but write it as @file{$(exec_prefix)/lib}. +(If you are using Autoconf, write it as @samp{@@libdir@@}.) + +@item infodir +The directory for installing the Info files for this package. By +default, it should be @file{/usr/local/info}, but it should be written +as @file{$(prefix)/info}. +(If you are using Autoconf, write it as @samp{@@infodir@@}.) + +@item lispdir +The directory for installing any Emacs Lisp files in this package. By +default, it should be @file{/usr/local/share/emacs/site-lisp}, but it +should be written as @file{$(prefix)/share/emacs/site-lisp}. + +If you are using Autoconf, write the default as @samp{@@lispdir@@}. +In order to make @samp{@@lispdir@@} work, you need the following lines +in your @file{configure.in} file: + +@example +lispdir='$@{datadir@}/emacs/site-lisp' +AC_SUBST(lispdir) +@end example + +@item includedir +@c rewritten to avoid overfull hbox --roland +The directory for installing header files to be included by user +programs with the C @samp{#include} preprocessor directive. This +should normally be @file{/usr/local/include}, but write it as +@file{$(prefix)/include}. +(If you are using Autoconf, write it as @samp{@@includedir@@}.) + +Most compilers other than GCC do not look for header files in directory +@file{/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 @code{includedir} and one +specified by @code{oldincludedir}. + +@item oldincludedir +The directory for installing @samp{#include} header files for use with +compilers other than GCC. This should normally be @file{/usr/include}. +(If you are using Autoconf, you can write it as @samp{@@oldincludedir@@}.) + +The Makefile commands should check whether the value of +@code{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 @file{foo.h}, then it should install the header +file in the @code{oldincludedir} directory if either (1) there is no +@file{foo.h} there or (2) the @file{foo.h} that exists came from the Foo +package. + +To tell whether @file{foo.h} came from the Foo package, put a magic +string in the file---part of a comment---and @code{grep} for that string. +@end table + +Unix-style man pages are installed in one of the following: + +@table @samp +@item mandir +The top-level directory for installing the man pages (if any) for this +package. It will normally be @file{/usr/local/man}, but you should +write it as @file{$(prefix)/man}. +(If you are using Autoconf, write it as @samp{@@mandir@@}.) + +@item man1dir +The directory for installing section 1 man pages. Write it as +@file{$(mandir)/man1}. +@item man2dir +The directory for installing section 2 man pages. Write it as +@file{$(mandir)/man2} +@item @dots{} + +@strong{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.} + +@item manext +The file name extension for the installed man page. This should contain +a period followed by the appropriate digit; it should normally be @samp{.1}. + +@item man1ext +The file name extension for installed section 1 man pages. +@item man2ext +The file name extension for installed section 2 man pages. +@item @dots{} +Use these names instead of @samp{manext} if the package needs to install man +pages in more than one section of the manual. +@end table + +And finally, you should set the following variable: + +@table @samp +@item srcdir +The directory for the sources being compiled. The value of this +variable is normally inserted by the @code{configure} shell script. +(If you are using Autconf, use @samp{srcdir = @@srcdir@@}.) +@end table + +For example: + +@smallexample +@c I have changed some of the comments here slightly to fix an overfull +@c hbox, so the make manual can format correctly. --roland +# 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 +@end smallexample + +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 @code{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. + +@node Standard Targets +@section Standard Targets for Users + +All GNU programs should have the following targets in their Makefiles: + +@table @samp +@item 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 @samp{-g}, so +that executable programs have debugging symbols. Users who don't mind +being helpless can strip the executables later if they wish. + +@item 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 @code{install-strip} target to do that. + +If possible, write the @code{install} target rule so that it does not +modify anything in the directory where the program was built, provided +@samp{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 @code{prefix} and +@code{exec_prefix}, as well as all subdirectories that are needed. +One way to do this is by means of an @code{installdirs} target +as described below. + +Use @samp{-} before any command for installing a man page, so that +@code{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 @file{$(infodir)} +with @code{$(INSTALL_DATA)} (@pxref{Command Variables}), and then run +the @code{install-info} program if it is present. @code{install-info} +is a program that edits the Info @file{dir} file to add or update the +menu entry for the given Info file; it is part of the Texinfo package. +Here is a sample rule to install an Info file: + +@comment This example has been carefully formatted for the Make manual. +@comment Please do not reformat it without talking to roland@gnu.ai.mit.edu. +@smallexample +$(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 +@end smallexample + +When writing the @code{install} target, you must classify all the +commands into three categories: normal ones, @dfn{pre-installation} +commands and @dfn{post-installation} commands. @xref{Install Command +Categories}. + +@item uninstall +Delete all the installed files---the copies that the @samp{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. @xref{Install Command Categories}. + +@item install-strip +Like @code{install}, but strip the executable files while installing +them. In simple cases, this target can use the @code{install} target in +a simple way: + +@smallexample +install-strip: + $(MAKE) INSTALL_PROGRAM='$(INSTALL_PROGRAM) -s' \ + install +@end smallexample + +But if the package installs scripts as well as real executables, the +@code{install-strip} target can't just refer to the @code{install} +target; it has to strip the executables but not the scripts. + +@code{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. + +@comment The gratuitous blank line here is to make the table look better +@comment in the printed Make manual. Please leave it in. +@item 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 @file{.dvi} files here if they are not part of the distribution. + +@item 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, @samp{make +distclean} should leave only the files that were in the distribution. + +@item mostlyclean +Like @samp{clean}, but may refrain from deleting a few files that people +normally don't want to recompile. For example, the @samp{mostlyclean} +target for GCC does not delete @file{libgcc.a}, because recompiling it +is rarely necessary and takes a lot of time. + +@item maintainer-clean +Delete almost everything from the current directory that can be +reconstructed with this Makefile. This typically includes everything +deleted by @code{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 +@samp{make maintainer-clean} should not delete @file{configure} even if +@file{configure} can be remade using a rule in the Makefile. More generally, +@samp{make maintainer-clean} should not delete anything that needs to +exist in order to run @file{configure} and then begin to build the +program. This is the only exception; @code{maintainer-clean} should +delete everything else that can be rebuilt. + +The @samp{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 @samp{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 +@code{maintainer-clean} target should start with these two: + +@smallexample +@@echo 'This command is intended for maintainers to use; it' +@@echo 'deletes files that may need special tools to rebuild.' +@end smallexample + +@item TAGS +Update a tags table for this program. +@c ADR: how? + +@item info +Generate any Info files needed. The best way to write the rules is as +follows: + +@smallexample +info: foo.info + +foo.info: foo.texi chap1.texi chap2.texi + $(MAKEINFO) $(srcdir)/foo.texi +@end smallexample + +@noindent +You must define the variable @code{MAKEINFO} in the Makefile. It should +run the @code{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. + +@item dvi +Generate DVI files for all Texinfo documentation. +For example: + +@smallexample +dvi: foo.dvi + +foo.dvi: foo.texi chap1.texi chap2.texi + $(TEXI2DVI) $(srcdir)/foo.texi +@end smallexample + +@noindent +You must define the variable @code{TEXI2DVI} in the Makefile. It should +run the program @code{texi2dvi}, which is part of the Texinfo +distribution.@footnote{@code{texi2dvi} uses @TeX{} to do the real work +of formatting. @TeX{} is not distributed with Texinfo.} Alternatively, +write just the dependencies, and allow GNU @code{make} to provide the command. + +@item dist +Create a distribution tar file for this program. The tar file should be +set up so that the file names in the tar file start with a subdirectory +name which is the name of the package it is a distribution for. This +name can include the version number. + +For example, the distribution tar file of GCC version 1.40 unpacks into +a subdirectory named @file{gcc-1.40}. + +The easiest way to do this is to create a subdirectory appropriately +named, use @code{ln} or @code{cp} to install the proper files in it, and +then @code{tar} that subdirectory. + +Compress the tar file with @code{gzip}. For example, the actual +distribution file for GCC version 1.40 is called @file{gcc-1.40.tar.gz}. + +The @code{dist} target should explicitly depend on all non-source files +that are in the distribution, to make sure they are up to date in the +distribution. +@ifset CODESTD +@xref{Releases, , Making Releases}. +@end ifset +@ifclear CODESTD +@xref{Releases, , Making Releases, standards, GNU Coding Standards}. +@end ifclear + +@item check +Perform self-tests (if any). The user must build the program before +running the tests, but need not install the program; you should write +the self-tests so that they work when the program is built but not +installed. +@end table + +The following targets are suggested as conventional names, for programs +in which they are useful. + +@table @code +@item installcheck +Perform installation tests (if any). The user must build and install +the program before running the tests. You should not assume that +@file{$(bindir)} is in the search path. + +@item installdirs +It's useful to add a target named @samp{installdirs} to create the +directories where files are installed, and their parent directories. +There is a script called @file{mkinstalldirs} which is convenient for +this; you can find it in the Texinfo package. +@c It's in /gd/gnu/lib/mkinstalldirs. +You can use a rule like this: + +@comment This has been carefully formatted to look decent in the Make manual. +@comment Please be sure not to make it extend any further to the right.--roland +@smallexample +# Make sure all installation directories (e.g. $(bindir)) +# actually exist by making them if necessary. +installdirs: mkinstalldirs + $(srcdir)/mkinstalldirs $(bindir) $(datadir) \ + $(libdir) $(infodir) \ + $(mandir) +@end smallexample + +@noindent +or, if you wish to support @env{DESTDIR}, + +@smallexample +# 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) +@end smallexample + +This rule should not modify the directories where compilation is done. +It should do nothing but create installation directories. +@end table + +@node Install Command Categories +@section Install Command Categories + +@cindex pre-installation commands +@cindex post-installation commands +When writing the @code{install} target, you must classify all the +commands into three categories: normal ones, @dfn{pre-installation} +commands and @dfn{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 +@code{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 @code{install} rule into these three +categories, insert @dfn{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 +@emph{should not} define them in the makefile). + +Here are the three possible category lines, each with a comment that +explains what it means: + +@smallexample + $(PRE_INSTALL) # @r{Pre-install commands follow.} + $(POST_INSTALL) # @r{Post-install commands follow.} + $(NORMAL_INSTALL) # @r{Normal commands follow.} +@end smallexample + +If you don't use a category line at the beginning of the @code{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 @code{uninstall}: + +@smallexample + $(PRE_UNINSTALL) # @r{Pre-uninstall commands follow.} + $(POST_UNINSTALL) # @r{Post-uninstall commands follow.} + $(NORMAL_UNINSTALL) # @r{Normal commands follow.} +@end smallexample + +Typically, a pre-uninstall command would be used for deleting entries +from the Info directory. + +If the @code{install} or @code{uninstall} target has any dependencies +which act as subroutines of installation, then you should start +@emph{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: + +@example +[ 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 +@end example + +@cindex binary packages +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: + +@smallexample +make -n install -o all \ + PRE_INSTALL=pre-install \ + POST_INSTALL=post-install \ + NORMAL_INSTALL=normal-install \ + | gawk -f pre-install.awk +@end smallexample + +@noindent +where the file @file{pre-install.awk} could contain this: + +@smallexample +$0 ~ /^\t[ \t]*(normal_install|post_install)[ \t]*$/ @{on = 0@} +on @{print $0@} +$0 ~ /^\t[ \t]*pre_install[ \t]*$/ @{on = 1@} +@end smallexample + +The resulting file of pre-installation commands is executed as a shell +script as part of installing the binary package. |