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1 | @comment This file is included by both standards.texi and make.texinfo. |
2 | @comment It was broken out of standards.texi on 1/6/93 by roland. | |
3 | ||
4 | @node Makefile Conventions | |
5 | @chapter Makefile Conventions | |
6 | @comment standards.texi does not print an index, but make.texinfo does. | |
7 | @cindex makefile, conventions for | |
8 | @cindex conventions for makefiles | |
9 | @cindex standards for makefiles | |
10 | ||
11 | This | |
12 | @ifinfo | |
13 | node | |
14 | @end ifinfo | |
15 | @iftex | |
16 | @ifset CODESTD | |
17 | section | |
18 | @end ifset | |
19 | @ifclear CODESTD | |
20 | chapter | |
21 | @end ifclear | |
22 | @end iftex | |
23 | describes conventions for writing the Makefiles for GNU programs. | |
24 | ||
25 | @menu | |
26 | * Makefile Basics:: General Conventions for Makefiles | |
27 | * Utilities in Makefiles:: Utilities in Makefiles | |
28 | * Command Variables:: Variables for Specifying Commands | |
29 | * Directory Variables:: Variables for Installation Directories | |
30 | * Standard Targets:: Standard Targets for Users | |
31 | * Install Command Categories:: Three categories of commands in the `install' | |
32 | rule: normal, pre-install and post-install. | |
33 | @end menu | |
34 | ||
35 | @node Makefile Basics | |
36 | @section General Conventions for Makefiles | |
37 | ||
38 | Every Makefile should contain this line: | |
39 | ||
40 | @example | |
41 | SHELL = /bin/sh | |
42 | @end example | |
43 | ||
44 | @noindent | |
45 | to avoid trouble on systems where the @code{SHELL} variable might be | |
46 | inherited from the environment. (This is never a problem with GNU | |
47 | @code{make}.) | |
48 | ||
49 | Different @code{make} programs have incompatible suffix lists and | |
50 | implicit rules, and this sometimes creates confusion or misbehavior. So | |
51 | it is a good idea to set the suffix list explicitly using only the | |
52 | suffixes you need in the particular Makefile, like this: | |
53 | ||
54 | @example | |
55 | .SUFFIXES: | |
56 | .SUFFIXES: .c .o | |
57 | @end example | |
58 | ||
59 | @noindent | |
60 | The first line clears out the suffix list, the second introduces all | |
61 | suffixes which may be subject to implicit rules in this Makefile. | |
62 | ||
63 | Don't assume that @file{.} is in the path for command execution. When | |
64 | you need to run programs that are a part of your package during the | |
65 | make, please make sure that it uses @file{./} if the program is built as | |
66 | part of the make or @file{$(srcdir)/} if the file is an unchanging part | |
67 | of the source code. Without one of these prefixes, the current search | |
68 | path is used. | |
69 | ||
70 | The distinction between @file{./} (the @dfn{build directory}) and | |
71 | @file{$(srcdir)/} (the @dfn{source directory}) is important because | |
72 | users can build in a separate directory using the @samp{--srcdir} option | |
73 | to @file{configure}. A rule of the form: | |
74 | ||
75 | @smallexample | |
76 | foo.1 : foo.man sedscript | |
77 | sed -e sedscript foo.man > foo.1 | |
78 | @end smallexample | |
79 | ||
80 | @noindent | |
81 | will fail when the build directory is not the source directory, because | |
82 | @file{foo.man} and @file{sedscript} are in the the source directory. | |
83 | ||
84 | When using GNU @code{make}, relying on @samp{VPATH} to find the source | |
85 | file will work in the case where there is a single dependency file, | |
86 | since the @code{make} automatic variable @samp{$<} will represent the | |
87 | source file wherever it is. (Many versions of @code{make} set @samp{$<} | |
88 | only in implicit rules.) A Makefile target like | |
89 | ||
90 | @smallexample | |
91 | foo.o : bar.c | |
92 | $(CC) -I. -I$(srcdir) $(CFLAGS) -c bar.c -o foo.o | |
93 | @end smallexample | |
94 | ||
95 | @noindent | |
96 | should instead be written as | |
97 | ||
98 | @smallexample | |
99 | foo.o : bar.c | |
100 | $(CC) -I. -I$(srcdir) $(CFLAGS) -c $< -o $@@ | |
101 | @end smallexample | |
102 | ||
103 | @noindent | |
104 | in order to allow @samp{VPATH} to work correctly. When the target has | |
105 | multiple dependencies, using an explicit @samp{$(srcdir)} is the easiest | |
106 | way to make the rule work well. For example, the target above for | |
107 | @file{foo.1} is best written as: | |
108 | ||
109 | @smallexample | |
110 | foo.1 : foo.man sedscript | |
111 | sed -e $(srcdir)/sedscript $(srcdir)/foo.man > $@@ | |
112 | @end smallexample | |
113 | ||
114 | GNU distributions usually contain some files which are not source | |
115 | files---for example, Info files, and the output from Autoconf, Automake, | |
116 | Bison or Flex. Since these files normally appear in the source | |
117 | directory, they should always appear in the source directory, not in the | |
118 | build directory. So Makefile rules to update them should put the | |
119 | updated files in the source directory. | |
120 | ||
121 | However, if a file does not appear in the distribution, then the | |
122 | Makefile should not put it in the source directory, because building a | |
123 | program in ordinary circumstances should not modify the source directory | |
124 | in any way. | |
125 | ||
126 | Try to make the build and installation targets, at least (and all their | |
127 | subtargets) work correctly with a parallel @code{make}. | |
128 | ||
129 | @node Utilities in Makefiles | |
130 | @section Utilities in Makefiles | |
131 | ||
132 | Write the Makefile commands (and any shell scripts, such as | |
133 | @code{configure}) to run in @code{sh}, not in @code{csh}. Don't use any | |
134 | special features of @code{ksh} or @code{bash}. | |
135 | ||
136 | The @code{configure} script and the Makefile rules for building and | |
137 | installation should not use any utilities directly except these: | |
138 | ||
139 | @c dd find | |
140 | @c gunzip gzip md5sum | |
141 | @c mkfifo mknod tee uname | |
142 | ||
143 | @example | |
144 | cat cmp cp diff echo egrep expr false grep install-info | |
145 | ln ls mkdir mv pwd rm rmdir sed sleep sort tar test touch true | |
146 | @end example | |
147 | ||
148 | The compression program @code{gzip} can be used in the @code{dist} rule. | |
149 | ||
150 | Stick to the generally supported options for these programs. For | |
151 | example, don't use @samp{mkdir -p}, convenient as it may be, because | |
152 | most systems don't support it. | |
153 | ||
154 | It is a good idea to avoid creating symbolic links in makefiles, since a | |
155 | few systems don't support them. | |
156 | ||
157 | The Makefile rules for building and installation can also use compilers | |
158 | and related programs, but should do so via @code{make} variables so that the | |
159 | user can substitute alternatives. Here are some of the programs we | |
160 | mean: | |
161 | ||
162 | @example | |
163 | ar bison cc flex install ld ldconfig lex | |
164 | make makeinfo ranlib texi2dvi yacc | |
165 | @end example | |
166 | ||
167 | Use the following @code{make} variables to run those programs: | |
168 | ||
169 | @example | |
170 | $(AR) $(BISON) $(CC) $(FLEX) $(INSTALL) $(LD) $(LDCONFIG) $(LEX) | |
171 | $(MAKE) $(MAKEINFO) $(RANLIB) $(TEXI2DVI) $(YACC) | |
172 | @end example | |
173 | ||
174 | When you use @code{ranlib} or @code{ldconfig}, you should make sure | |
175 | nothing bad happens if the system does not have the program in question. | |
176 | Arrange to ignore an error from that command, and print a message before | |
177 | the command to tell the user that failure of this command does not mean | |
178 | a problem. (The Autoconf @samp{AC_PROG_RANLIB} macro can help with | |
179 | this.) | |
180 | ||
181 | If you use symbolic links, you should implement a fallback for systems | |
182 | that don't have symbolic links. | |
183 | ||
184 | Additional utilities that can be used via Make variables are: | |
185 | ||
186 | @example | |
187 | chgrp chmod chown mknod | |
188 | @end example | |
189 | ||
190 | It is ok to use other utilities in Makefile portions (or scripts) | |
191 | intended only for particular systems where you know those utilities | |
192 | exist. | |
193 | ||
194 | @node Command Variables | |
195 | @section Variables for Specifying Commands | |
196 | ||
197 | Makefiles should provide variables for overriding certain commands, options, | |
198 | and so on. | |
199 | ||
200 | In particular, you should run most utility programs via variables. | |
201 | Thus, if you use Bison, have a variable named @code{BISON} whose default | |
202 | value is set with @samp{BISON = bison}, and refer to it with | |
203 | @code{$(BISON)} whenever you need to use Bison. | |
204 | ||
205 | File management utilities such as @code{ln}, @code{rm}, @code{mv}, and | |
206 | so on, need not be referred to through variables in this way, since users | |
207 | don't need to replace them with other programs. | |
208 | ||
209 | Each program-name variable should come with an options variable that is | |
210 | used to supply options to the program. Append @samp{FLAGS} to the | |
211 | program-name variable name to get the options variable name---for | |
212 | example, @code{BISONFLAGS}. (The names @code{CFLAGS} for the C | |
213 | compiler, @code{YFLAGS} for yacc, and @code{LFLAGS} for lex, are | |
214 | exceptions to this rule, but we keep them because they are standard.) | |
215 | Use @code{CPPFLAGS} in any compilation command that runs the | |
216 | preprocessor, and use @code{LDFLAGS} in any compilation command that | |
217 | does linking as well as in any direct use of @code{ld}. | |
218 | ||
219 | If there are C compiler options that @emph{must} be used for proper | |
220 | compilation of certain files, do not include them in @code{CFLAGS}. | |
221 | Users expect to be able to specify @code{CFLAGS} freely themselves. | |
222 | Instead, arrange to pass the necessary options to the C compiler | |
223 | independently of @code{CFLAGS}, by writing them explicitly in the | |
224 | compilation commands or by defining an implicit rule, like this: | |
225 | ||
226 | @smallexample | |
227 | CFLAGS = -g | |
228 | ALL_CFLAGS = -I. $(CFLAGS) | |
229 | .c.o: | |
230 | $(CC) -c $(CPPFLAGS) $(ALL_CFLAGS) $< | |
231 | @end smallexample | |
232 | ||
233 | Do include the @samp{-g} option in @code{CFLAGS}, because that is not | |
234 | @emph{required} for proper compilation. You can consider it a default | |
235 | that is only recommended. If the package is set up so that it is | |
236 | compiled with GCC by default, then you might as well include @samp{-O} | |
237 | in the default value of @code{CFLAGS} as well. | |
238 | ||
239 | Put @code{CFLAGS} last in the compilation command, after other variables | |
240 | containing compiler options, so the user can use @code{CFLAGS} to | |
241 | override the others. | |
242 | ||
243 | @code{CFLAGS} should be used in every invocation of the C compiler, | |
244 | both those which do compilation and those which do linking. | |
245 | ||
246 | Every Makefile should define the variable @code{INSTALL}, which is the | |
247 | basic command for installing a file into the system. | |
248 | ||
249 | Every Makefile should also define the variables @code{INSTALL_PROGRAM} | |
250 | and @code{INSTALL_DATA}. (The default for each of these should be | |
251 | @code{$(INSTALL)}.) Then it should use those variables as the commands | |
252 | for actual installation, for executables and nonexecutables | |
253 | respectively. Use these variables as follows: | |
254 | ||
255 | @example | |
256 | $(INSTALL_PROGRAM) foo $(bindir)/foo | |
257 | $(INSTALL_DATA) libfoo.a $(libdir)/libfoo.a | |
258 | @end example | |
259 | ||
260 | Optionally, you may prepend the value of @code{DESTDIR} to the target | |
261 | filename. Doing this allows the installer to create a snapshot of the | |
262 | installation to be copied onto the real target filesystem later. Do not | |
263 | set the value of @code{DESTDIR} in your Makefile, and do not include it | |
264 | in any installed files. With support for @code{DESTDIR}, the above | |
265 | examples become: | |
266 | ||
267 | @example | |
268 | $(INSTALL_PROGRAM) foo $(DESTDIR)$(bindir)/foo | |
269 | $(INSTALL_DATA) libfoo.a $(DESTDIR)$(libdir)/libfoo.a | |
270 | @end example | |
271 | ||
272 | @noindent | |
273 | Always use a file name, not a directory name, as the second argument of | |
274 | the installation commands. Use a separate command for each file to be | |
275 | installed. | |
276 | ||
277 | @node Directory Variables | |
278 | @section Variables for Installation Directories | |
279 | ||
280 | Installation directories should always be named by variables, so it is | |
281 | easy to install in a nonstandard place. The standard names for these | |
282 | variables are described below. They are based on a standard filesystem | |
283 | layout; variants of it are used in SVR4, 4.4BSD, Linux, Ultrix v4, and | |
284 | other modern operating systems. | |
285 | ||
286 | These two variables set the root for the installation. All the other | |
287 | installation directories should be subdirectories of one of these two, | |
288 | and nothing should be directly installed into these two directories. | |
289 | ||
290 | @table @samp | |
291 | @item prefix | |
292 | A prefix used in constructing the default values of the variables listed | |
293 | below. The default value of @code{prefix} should be @file{/usr/local}. | |
294 | When building the complete GNU system, the prefix will be empty and | |
295 | @file{/usr} will be a symbolic link to @file{/}. | |
296 | (If you are using Autoconf, write it as @samp{@@prefix@@}.) | |
297 | ||
298 | Running @samp{make install} with a different value of @code{prefix} | |
299 | from the one used to build the program should @var{not} recompile | |
300 | the program. | |
301 | ||
302 | @item exec_prefix | |
303 | A prefix used in constructing the default values of some of the | |
304 | variables listed below. The default value of @code{exec_prefix} should | |
305 | be @code{$(prefix)}. | |
306 | (If you are using Autoconf, write it as @samp{@@exec_prefix@@}.) | |
307 | ||
308 | Generally, @code{$(exec_prefix)} is used for directories that contain | |
309 | machine-specific files (such as executables and subroutine libraries), | |
310 | while @code{$(prefix)} is used directly for other directories. | |
311 | ||
312 | Running @samp{make install} with a different value of @code{exec_prefix} | |
313 | from the one used to build the program should @var{not} recompile the | |
314 | program. | |
315 | @end table | |
316 | ||
317 | Executable programs are installed in one of the following directories. | |
318 | ||
319 | @table @samp | |
320 | @item bindir | |
321 | The directory for installing executable programs that users can run. | |
322 | This should normally be @file{/usr/local/bin}, but write it as | |
323 | @file{$(exec_prefix)/bin}. | |
324 | (If you are using Autoconf, write it as @samp{@@bindir@@}.) | |
325 | ||
326 | @item sbindir | |
327 | The directory for installing executable programs that can be run from | |
328 | the shell, but are only generally useful to system administrators. This | |
329 | should normally be @file{/usr/local/sbin}, but write it as | |
330 | @file{$(exec_prefix)/sbin}. | |
331 | (If you are using Autoconf, write it as @samp{@@sbindir@@}.) | |
332 | ||
333 | @item libexecdir | |
334 | @comment This paragraph adjusted to avoid overfull hbox --roland 5jul94 | |
335 | The directory for installing executable programs to be run by other | |
336 | programs rather than by users. This directory should normally be | |
337 | @file{/usr/local/libexec}, but write it as @file{$(exec_prefix)/libexec}. | |
338 | (If you are using Autoconf, write it as @samp{@@libexecdir@@}.) | |
339 | @end table | |
340 | ||
341 | Data files used by the program during its execution are divided into | |
342 | categories in two ways. | |
343 | ||
344 | @itemize @bullet | |
345 | @item | |
346 | Some files are normally modified by programs; others are never normally | |
347 | modified (though users may edit some of these). | |
348 | ||
349 | @item | |
350 | Some files are architecture-independent and can be shared by all | |
351 | machines at a site; some are architecture-dependent and can be shared | |
352 | only by machines of the same kind and operating system; others may never | |
353 | be shared between two machines. | |
354 | @end itemize | |
355 | ||
356 | This makes for six different possibilities. However, we want to | |
357 | discourage the use of architecture-dependent files, aside from object | |
358 | files and libraries. It is much cleaner to make other data files | |
359 | architecture-independent, and it is generally not hard. | |
360 | ||
361 | Therefore, here are the variables Makefiles should use to specify | |
362 | directories: | |
363 | ||
364 | @table @samp | |
365 | @item datadir | |
366 | The directory for installing read-only architecture independent data | |
367 | files. This should normally be @file{/usr/local/share}, but write it as | |
368 | @file{$(prefix)/share}. | |
369 | (If you are using Autoconf, write it as @samp{@@datadir@@}.) | |
370 | As a special exception, see @file{$(infodir)} | |
371 | and @file{$(includedir)} below. | |
372 | ||
373 | @item sysconfdir | |
374 | The directory for installing read-only data files that pertain to a | |
375 | single machine--that is to say, files for configuring a host. Mailer | |
376 | and network configuration files, @file{/etc/passwd}, and so forth belong | |
377 | here. All the files in this directory should be ordinary ASCII text | |
378 | files. This directory should normally be @file{/usr/local/etc}, but | |
379 | write it as @file{$(prefix)/etc}. | |
380 | (If you are using Autoconf, write it as @samp{@@sysconfdir@@}.) | |
381 | ||
382 | Do not install executables here in this directory (they probably belong | |
383 | in @file{$(libexecdir)} or @file{$(sbindir)}). Also do not install | |
384 | files that are modified in the normal course of their use (programs | |
385 | whose purpose is to change the configuration of the system excluded). | |
386 | Those probably belong in @file{$(localstatedir)}. | |
387 | ||
388 | @item sharedstatedir | |
389 | The directory for installing architecture-independent data files which | |
390 | the programs modify while they run. This should normally be | |
391 | @file{/usr/local/com}, but write it as @file{$(prefix)/com}. | |
392 | (If you are using Autoconf, write it as @samp{@@sharedstatedir@@}.) | |
393 | ||
394 | @item localstatedir | |
395 | The directory for installing data files which the programs modify while | |
396 | they run, and that pertain to one specific machine. Users should never | |
397 | need to modify files in this directory to configure the package's | |
398 | operation; put such configuration information in separate files that go | |
399 | in @file{$(datadir)} or @file{$(sysconfdir)}. @file{$(localstatedir)} | |
400 | should normally be @file{/usr/local/var}, but write it as | |
401 | @file{$(prefix)/var}. | |
402 | (If you are using Autoconf, write it as @samp{@@localstatedir@@}.) | |
403 | ||
404 | @item libdir | |
405 | The directory for object files and libraries of object code. Do not | |
406 | install executables here, they probably ought to go in @file{$(libexecdir)} | |
407 | instead. The value of @code{libdir} should normally be | |
408 | @file{/usr/local/lib}, but write it as @file{$(exec_prefix)/lib}. | |
409 | (If you are using Autoconf, write it as @samp{@@libdir@@}.) | |
410 | ||
411 | @item infodir | |
412 | The directory for installing the Info files for this package. By | |
413 | default, it should be @file{/usr/local/info}, but it should be written | |
414 | as @file{$(prefix)/info}. | |
415 | (If you are using Autoconf, write it as @samp{@@infodir@@}.) | |
416 | ||
417 | @item lispdir | |
418 | The directory for installing any Emacs Lisp files in this package. By | |
419 | default, it should be @file{/usr/local/share/emacs/site-lisp}, but it | |
420 | should be written as @file{$(prefix)/share/emacs/site-lisp}. | |
421 | ||
422 | If you are using Autoconf, write the default as @samp{@@lispdir@@}. | |
423 | In order to make @samp{@@lispdir@@} work, you need the following lines | |
424 | in your @file{configure.in} file: | |
425 | ||
426 | @example | |
427 | lispdir='$@{datadir@}/emacs/site-lisp' | |
428 | AC_SUBST(lispdir) | |
429 | @end example | |
430 | ||
431 | @item includedir | |
432 | @c rewritten to avoid overfull hbox --roland | |
433 | The directory for installing header files to be included by user | |
434 | programs with the C @samp{#include} preprocessor directive. This | |
435 | should normally be @file{/usr/local/include}, but write it as | |
436 | @file{$(prefix)/include}. | |
437 | (If you are using Autoconf, write it as @samp{@@includedir@@}.) | |
438 | ||
439 | Most compilers other than GCC do not look for header files in directory | |
440 | @file{/usr/local/include}. So installing the header files this way is | |
441 | only useful with GCC. Sometimes this is not a problem because some | |
442 | libraries are only really intended to work with GCC. But some libraries | |
443 | are intended to work with other compilers. They should install their | |
444 | header files in two places, one specified by @code{includedir} and one | |
445 | specified by @code{oldincludedir}. | |
446 | ||
447 | @item oldincludedir | |
448 | The directory for installing @samp{#include} header files for use with | |
449 | compilers other than GCC. This should normally be @file{/usr/include}. | |
450 | (If you are using Autoconf, you can write it as @samp{@@oldincludedir@@}.) | |
451 | ||
452 | The Makefile commands should check whether the value of | |
453 | @code{oldincludedir} is empty. If it is, they should not try to use | |
454 | it; they should cancel the second installation of the header files. | |
455 | ||
456 | A package should not replace an existing header in this directory unless | |
457 | the header came from the same package. Thus, if your Foo package | |
458 | provides a header file @file{foo.h}, then it should install the header | |
459 | file in the @code{oldincludedir} directory if either (1) there is no | |
460 | @file{foo.h} there or (2) the @file{foo.h} that exists came from the Foo | |
461 | package. | |
462 | ||
463 | To tell whether @file{foo.h} came from the Foo package, put a magic | |
464 | string in the file---part of a comment---and @code{grep} for that string. | |
465 | @end table | |
466 | ||
467 | Unix-style man pages are installed in one of the following: | |
468 | ||
469 | @table @samp | |
470 | @item mandir | |
471 | The top-level directory for installing the man pages (if any) for this | |
472 | package. It will normally be @file{/usr/local/man}, but you should | |
473 | write it as @file{$(prefix)/man}. | |
474 | (If you are using Autoconf, write it as @samp{@@mandir@@}.) | |
475 | ||
476 | @item man1dir | |
477 | The directory for installing section 1 man pages. Write it as | |
478 | @file{$(mandir)/man1}. | |
479 | @item man2dir | |
480 | The directory for installing section 2 man pages. Write it as | |
481 | @file{$(mandir)/man2} | |
482 | @item @dots{} | |
483 | ||
484 | @strong{Don't make the primary documentation for any GNU software be a | |
485 | man page. Write a manual in Texinfo instead. Man pages are just for | |
486 | the sake of people running GNU software on Unix, which is a secondary | |
487 | application only.} | |
488 | ||
489 | @item manext | |
490 | The file name extension for the installed man page. This should contain | |
491 | a period followed by the appropriate digit; it should normally be @samp{.1}. | |
492 | ||
493 | @item man1ext | |
494 | The file name extension for installed section 1 man pages. | |
495 | @item man2ext | |
496 | The file name extension for installed section 2 man pages. | |
497 | @item @dots{} | |
498 | Use these names instead of @samp{manext} if the package needs to install man | |
499 | pages in more than one section of the manual. | |
500 | @end table | |
501 | ||
502 | And finally, you should set the following variable: | |
503 | ||
504 | @table @samp | |
505 | @item srcdir | |
506 | The directory for the sources being compiled. The value of this | |
507 | variable is normally inserted by the @code{configure} shell script. | |
508 | (If you are using Autconf, use @samp{srcdir = @@srcdir@@}.) | |
509 | @end table | |
510 | ||
511 | For example: | |
512 | ||
513 | @smallexample | |
514 | @c I have changed some of the comments here slightly to fix an overfull | |
515 | @c hbox, so the make manual can format correctly. --roland | |
516 | # Common prefix for installation directories. | |
517 | # NOTE: This directory must exist when you start the install. | |
518 | prefix = /usr/local | |
519 | exec_prefix = $(prefix) | |
520 | # Where to put the executable for the command `gcc'. | |
521 | bindir = $(exec_prefix)/bin | |
522 | # Where to put the directories used by the compiler. | |
523 | libexecdir = $(exec_prefix)/libexec | |
524 | # Where to put the Info files. | |
525 | infodir = $(prefix)/info | |
526 | @end smallexample | |
527 | ||
528 | If your program installs a large number of files into one of the | |
529 | standard user-specified directories, it might be useful to group them | |
530 | into a subdirectory particular to that program. If you do this, you | |
531 | should write the @code{install} rule to create these subdirectories. | |
532 | ||
533 | Do not expect the user to include the subdirectory name in the value of | |
534 | any of the variables listed above. The idea of having a uniform set of | |
535 | variable names for installation directories is to enable the user to | |
536 | specify the exact same values for several different GNU packages. In | |
537 | order for this to be useful, all the packages must be designed so that | |
538 | they will work sensibly when the user does so. | |
539 | ||
540 | @node Standard Targets | |
541 | @section Standard Targets for Users | |
542 | ||
543 | All GNU programs should have the following targets in their Makefiles: | |
544 | ||
545 | @table @samp | |
546 | @item all | |
547 | Compile the entire program. This should be the default target. This | |
548 | target need not rebuild any documentation files; Info files should | |
549 | normally be included in the distribution, and DVI files should be made | |
550 | only when explicitly asked for. | |
551 | ||
552 | By default, the Make rules should compile and link with @samp{-g}, so | |
553 | that executable programs have debugging symbols. Users who don't mind | |
554 | being helpless can strip the executables later if they wish. | |
555 | ||
556 | @item install | |
557 | Compile the program and copy the executables, libraries, and so on to | |
558 | the file names where they should reside for actual use. If there is a | |
559 | simple test to verify that a program is properly installed, this target | |
560 | should run that test. | |
561 | ||
562 | Do not strip executables when installing them. Devil-may-care users can | |
563 | use the @code{install-strip} target to do that. | |
564 | ||
565 | If possible, write the @code{install} target rule so that it does not | |
566 | modify anything in the directory where the program was built, provided | |
567 | @samp{make all} has just been done. This is convenient for building the | |
568 | program under one user name and installing it under another. | |
569 | ||
570 | The commands should create all the directories in which files are to be | |
571 | installed, if they don't already exist. This includes the directories | |
572 | specified as the values of the variables @code{prefix} and | |
573 | @code{exec_prefix}, as well as all subdirectories that are needed. | |
574 | One way to do this is by means of an @code{installdirs} target | |
575 | as described below. | |
576 | ||
577 | Use @samp{-} before any command for installing a man page, so that | |
578 | @code{make} will ignore any errors. This is in case there are systems | |
579 | that don't have the Unix man page documentation system installed. | |
580 | ||
581 | The way to install Info files is to copy them into @file{$(infodir)} | |
582 | with @code{$(INSTALL_DATA)} (@pxref{Command Variables}), and then run | |
583 | the @code{install-info} program if it is present. @code{install-info} | |
584 | is a program that edits the Info @file{dir} file to add or update the | |
585 | menu entry for the given Info file; it is part of the Texinfo package. | |
586 | Here is a sample rule to install an Info file: | |
587 | ||
588 | @comment This example has been carefully formatted for the Make manual. | |
589 | @comment Please do not reformat it without talking to roland@gnu.ai.mit.edu. | |
590 | @smallexample | |
591 | $(DESTDIR)$(infodir)/foo.info: foo.info | |
592 | $(POST_INSTALL) | |
593 | # There may be a newer info file in . than in srcdir. | |
594 | -if test -f foo.info; then d=.; \ | |
595 | else d=$(srcdir); fi; \ | |
596 | $(INSTALL_DATA) $$d/foo.info $(DESTDIR)$@@; \ | |
597 | # Run install-info only if it exists. | |
598 | # Use `if' instead of just prepending `-' to the | |
599 | # line so we notice real errors from install-info. | |
600 | # We use `$(SHELL) -c' because some shells do not | |
601 | # fail gracefully when there is an unknown command. | |
602 | if $(SHELL) -c 'install-info --version' \ | |
603 | >/dev/null 2>&1; then \ | |
604 | install-info --dir-file=$(DESTDIR)$(infodir)/dir \ | |
605 | $(DESTDIR)$(infodir)/foo.info; \ | |
606 | else true; fi | |
607 | @end smallexample | |
608 | ||
609 | When writing the @code{install} target, you must classify all the | |
610 | commands into three categories: normal ones, @dfn{pre-installation} | |
611 | commands and @dfn{post-installation} commands. @xref{Install Command | |
612 | Categories}. | |
613 | ||
614 | @item uninstall | |
615 | Delete all the installed files---the copies that the @samp{install} | |
616 | target creates. | |
617 | ||
618 | This rule should not modify the directories where compilation is done, | |
619 | only the directories where files are installed. | |
620 | ||
621 | The uninstallation commands are divided into three categories, just like | |
622 | the installation commands. @xref{Install Command Categories}. | |
623 | ||
624 | @item install-strip | |
625 | Like @code{install}, but strip the executable files while installing | |
626 | them. In many cases, the definition of this target can be very simple: | |
627 | ||
628 | @smallexample | |
629 | install-strip: | |
630 | $(MAKE) INSTALL_PROGRAM='$(INSTALL_PROGRAM) -s' \ | |
631 | install | |
632 | @end smallexample | |
633 | ||
634 | Normally we do not recommend stripping an executable unless you are sure | |
635 | the program has no bugs. However, it can be reasonable to install a | |
636 | stripped executable for actual execution while saving the unstripped | |
637 | executable elsewhere in case there is a bug. | |
638 | ||
639 | @comment The gratuitous blank line here is to make the table look better | |
640 | @comment in the printed Make manual. Please leave it in. | |
641 | @item clean | |
642 | ||
643 | Delete all files from the current directory that are normally created by | |
644 | building the program. Don't delete the files that record the | |
645 | configuration. Also preserve files that could be made by building, but | |
646 | normally aren't because the distribution comes with them. | |
647 | ||
648 | Delete @file{.dvi} files here if they are not part of the distribution. | |
649 | ||
650 | @item distclean | |
651 | Delete all files from the current directory that are created by | |
652 | configuring or building the program. If you have unpacked the source | |
653 | and built the program without creating any other files, @samp{make | |
654 | distclean} should leave only the files that were in the distribution. | |
655 | ||
656 | @item mostlyclean | |
657 | Like @samp{clean}, but may refrain from deleting a few files that people | |
658 | normally don't want to recompile. For example, the @samp{mostlyclean} | |
659 | target for GCC does not delete @file{libgcc.a}, because recompiling it | |
660 | is rarely necessary and takes a lot of time. | |
661 | ||
662 | @item maintainer-clean | |
663 | Delete almost everything from the current directory that can be | |
664 | reconstructed with this Makefile. This typically includes everything | |
665 | deleted by @code{distclean}, plus more: C source files produced by | |
666 | Bison, tags tables, Info files, and so on. | |
667 | ||
668 | The reason we say ``almost everything'' is that running the command | |
669 | @samp{make maintainer-clean} should not delete @file{configure} even if | |
670 | @file{configure} can be remade using a rule in the Makefile. More generally, | |
671 | @samp{make maintainer-clean} should not delete anything that needs to | |
672 | exist in order to run @file{configure} and then begin to build the | |
673 | program. This is the only exception; @code{maintainer-clean} should | |
674 | delete everything else that can be rebuilt. | |
675 | ||
676 | The @samp{maintainer-clean} target is intended to be used by a maintainer of | |
677 | the package, not by ordinary users. You may need special tools to | |
678 | reconstruct some of the files that @samp{make maintainer-clean} deletes. | |
679 | Since these files are normally included in the distribution, we don't | |
680 | take care to make them easy to reconstruct. If you find you need to | |
681 | unpack the full distribution again, don't blame us. | |
682 | ||
683 | To help make users aware of this, the commands for the special | |
684 | @code{maintainer-clean} target should start with these two: | |
685 | ||
686 | @smallexample | |
687 | @@echo 'This command is intended for maintainers to use; it' | |
688 | @@echo 'deletes files that may need special tools to rebuild.' | |
689 | @end smallexample | |
690 | ||
691 | @item TAGS | |
692 | Update a tags table for this program. | |
693 | @c ADR: how? | |
694 | ||
695 | @item info | |
696 | Generate any Info files needed. The best way to write the rules is as | |
697 | follows: | |
698 | ||
699 | @smallexample | |
700 | info: foo.info | |
701 | ||
702 | foo.info: foo.texi chap1.texi chap2.texi | |
703 | $(MAKEINFO) $(srcdir)/foo.texi | |
704 | @end smallexample | |
705 | ||
706 | @noindent | |
707 | You must define the variable @code{MAKEINFO} in the Makefile. It should | |
708 | run the @code{makeinfo} program, which is part of the Texinfo | |
709 | distribution. | |
710 | ||
711 | Normally a GNU distribution comes with Info files, and that means the | |
712 | Info files are present in the source directory. Therefore, the Make | |
713 | rule for an info file should update it in the source directory. When | |
714 | users build the package, ordinarily Make will not update the Info files | |
715 | because they will already be up to date. | |
716 | ||
717 | @item dvi | |
718 | Generate DVI files for all Texinfo documentation. | |
719 | For example: | |
720 | ||
721 | @smallexample | |
722 | dvi: foo.dvi | |
723 | ||
724 | foo.dvi: foo.texi chap1.texi chap2.texi | |
725 | $(TEXI2DVI) $(srcdir)/foo.texi | |
726 | @end smallexample | |
727 | ||
728 | @noindent | |
729 | You must define the variable @code{TEXI2DVI} in the Makefile. It should | |
730 | run the program @code{texi2dvi}, which is part of the Texinfo | |
731 | distribution.@footnote{@code{texi2dvi} uses @TeX{} to do the real work | |
732 | of formatting. @TeX{} is not distributed with Texinfo.} Alternatively, | |
733 | write just the dependencies, and allow GNU @code{make} to provide the command. | |
734 | ||
735 | @item dist | |
736 | Create a distribution tar file for this program. The tar file should be | |
737 | set up so that the file names in the tar file start with a subdirectory | |
738 | name which is the name of the package it is a distribution for. This | |
739 | name can include the version number. | |
740 | ||
741 | For example, the distribution tar file of GCC version 1.40 unpacks into | |
742 | a subdirectory named @file{gcc-1.40}. | |
743 | ||
744 | The easiest way to do this is to create a subdirectory appropriately | |
745 | named, use @code{ln} or @code{cp} to install the proper files in it, and | |
746 | then @code{tar} that subdirectory. | |
747 | ||
748 | Compress the tar file file with @code{gzip}. For example, the actual | |
749 | distribution file for GCC version 1.40 is called @file{gcc-1.40.tar.gz}. | |
750 | ||
751 | The @code{dist} target should explicitly depend on all non-source files | |
752 | that are in the distribution, to make sure they are up to date in the | |
753 | distribution. | |
754 | @ifset CODESTD | |
755 | @xref{Releases, , Making Releases}. | |
756 | @end ifset | |
757 | @ifclear CODESTD | |
758 | @xref{Releases, , Making Releases, standards, GNU Coding Standards}. | |
759 | @end ifclear | |
760 | ||
761 | @item check | |
762 | Perform self-tests (if any). The user must build the program before | |
763 | running the tests, but need not install the program; you should write | |
764 | the self-tests so that they work when the program is built but not | |
765 | installed. | |
766 | @end table | |
767 | ||
768 | The following targets are suggested as conventional names, for programs | |
769 | in which they are useful. | |
770 | ||
771 | @table @code | |
772 | @item installcheck | |
773 | Perform installation tests (if any). The user must build and install | |
774 | the program before running the tests. You should not assume that | |
775 | @file{$(bindir)} is in the search path. | |
776 | ||
777 | @item installdirs | |
778 | It's useful to add a target named @samp{installdirs} to create the | |
779 | directories where files are installed, and their parent directories. | |
780 | There is a script called @file{mkinstalldirs} which is convenient for | |
781 | this; you can find it in the Texinfo package. | |
782 | @c It's in /gd/gnu/lib/mkinstalldirs. | |
783 | You can use a rule like this: | |
784 | ||
785 | @comment This has been carefully formatted to look decent in the Make manual. | |
786 | @comment Please be sure not to make it extend any further to the right.--roland | |
787 | @smallexample | |
788 | # Make sure all installation directories (e.g. $(bindir)) | |
789 | # actually exist by making them if necessary. | |
790 | installdirs: mkinstalldirs | |
791 | $(srcdir)/mkinstalldirs $(bindir) $(datadir) \ | |
792 | $(libdir) $(infodir) \ | |
793 | $(mandir) | |
794 | @end smallexample | |
795 | ||
796 | This rule should not modify the directories where compilation is done. | |
797 | It should do nothing but create installation directories. | |
798 | @end table | |
799 | ||
800 | @node Install Command Categories | |
801 | @section Install Command Categories | |
802 | ||
803 | @cindex pre-installation commands | |
804 | @cindex post-installation commands | |
805 | When writing the @code{install} target, you must classify all the | |
806 | commands into three categories: normal ones, @dfn{pre-installation} | |
807 | commands and @dfn{post-installation} commands. | |
808 | ||
809 | Normal commands move files into their proper places, and set their | |
810 | modes. They may not alter any files except the ones that come entirely | |
811 | from the package they belong to. | |
812 | ||
813 | Pre-installation and post-installation commands may alter other files; | |
814 | in particular, they can edit global configuration files or data bases. | |
815 | ||
816 | Pre-installation commands are typically executed before the normal | |
817 | commands, and post-installation commands are typically run after the | |
818 | normal commands. | |
819 | ||
820 | The most common use for a post-installation command is to run | |
821 | @code{install-info}. This cannot be done with a normal command, since | |
822 | it alters a file (the Info directory) which does not come entirely and | |
823 | solely from the package being installed. It is a post-installation | |
824 | command because it needs to be done after the normal command which | |
825 | installs the package's Info files. | |
826 | ||
827 | Most programs don't need any pre-installation commands, but we have the | |
828 | feature just in case it is needed. | |
829 | ||
830 | To classify the commands in the @code{install} rule into these three | |
831 | categories, insert @dfn{category lines} among them. A category line | |
832 | specifies the category for the commands that follow. | |
833 | ||
834 | A category line consists of a tab and a reference to a special Make | |
835 | variable, plus an optional comment at the end. There are three | |
836 | variables you can use, one for each category; the variable name | |
837 | specifies the category. Category lines are no-ops in ordinary execution | |
838 | because these three Make variables are normally undefined (and you | |
839 | @emph{should not} define them in the makefile). | |
840 | ||
841 | Here are the three possible category lines, each with a comment that | |
842 | explains what it means: | |
843 | ||
844 | @smallexample | |
845 | $(PRE_INSTALL) # @r{Pre-install commands follow.} | |
846 | $(POST_INSTALL) # @r{Post-install commands follow.} | |
847 | $(NORMAL_INSTALL) # @r{Normal commands follow.} | |
848 | @end smallexample | |
849 | ||
850 | If you don't use a category line at the beginning of the @code{install} | |
851 | rule, all the commands are classified as normal until the first category | |
852 | line. If you don't use any category lines, all the commands are | |
853 | classified as normal. | |
854 | ||
855 | These are the category lines for @code{uninstall}: | |
856 | ||
857 | @smallexample | |
858 | $(PRE_UNINSTALL) # @r{Pre-uninstall commands follow.} | |
859 | $(POST_UNINSTALL) # @r{Post-uninstall commands follow.} | |
860 | $(NORMAL_UNINSTALL) # @r{Normal commands follow.} | |
861 | @end smallexample | |
862 | ||
863 | Typically, a pre-uninstall command would be used for deleting entries | |
864 | from the Info directory. | |
865 | ||
866 | If the @code{install} or @code{uninstall} target has any dependencies | |
867 | which act as subroutines of installation, then you should start | |
868 | @emph{each} dependency's commands with a category line, and start the | |
869 | main target's commands with a category line also. This way, you can | |
870 | ensure that each command is placed in the right category regardless of | |
871 | which of the dependencies actually run. | |
872 | ||
873 | Pre-installation and post-installation commands should not run any | |
874 | programs except for these: | |
875 | ||
876 | @example | |
877 | [ basename bash cat chgrp chmod chown cmp cp dd diff echo | |
878 | egrep expand expr false fgrep find getopt grep gunzip gzip | |
879 | hostname install install-info kill ldconfig ln ls md5sum | |
880 | mkdir mkfifo mknod mv printenv pwd rm rmdir sed sort tee | |
881 | test touch true uname xargs yes | |
882 | @end example | |
883 | ||
884 | @cindex binary packages | |
885 | The reason for distinguishing the commands in this way is for the sake | |
886 | of making binary packages. Typically a binary package contains all the | |
887 | executables and other files that need to be installed, and has its own | |
888 | method of installing them---so it does not need to run the normal | |
889 | installation commands. But installing the binary package does need to | |
890 | execute the pre-installation and post-installation commands. | |
891 | ||
892 | Programs to build binary packages work by extracting the | |
893 | pre-installation and post-installation commands. Here is one way of | |
894 | extracting the pre-installation commands: | |
895 | ||
896 | @smallexample | |
897 | make -n install -o all \ | |
898 | PRE_INSTALL=pre-install \ | |
899 | POST_INSTALL=post-install \ | |
900 | NORMAL_INSTALL=normal-install \ | |
901 | | gawk -f pre-install.awk | |
902 | @end smallexample | |
903 | ||
904 | @noindent | |
905 | where the file @file{pre-install.awk} could contain this: | |
906 | ||
907 | @smallexample | |
908 | $0 ~ /^\t[ \t]*(normal_install|post_install)[ \t]*$/ @{on = 0@} | |
909 | on @{print $0@} | |
910 | $0 ~ /^\t[ \t]*pre_install[ \t]*$/ @{on = 1@} | |
911 | @end smallexample | |
912 | ||
913 | The resulting file of pre-installation commands is executed as a shell | |
914 | script as part of installing the binary package. |