1Installation Instructions
2*************************
3
4   Copyright (C) 1994-1996, 1999-2002, 2004-2017, 2020-2021 Free
5Software Foundation, Inc.
6
7   Copying and distribution of this file, with or without modification,
8are permitted in any medium without royalty provided the copyright
9notice and this notice are preserved.  This file is offered as-is,
10without warranty of any kind.
11
12Basic Installation
13==================
14
15   Briefly, the shell command './configure && make && make install'
16should configure, build, and install this package.  The following
17more-detailed instructions are generic; see the 'README' file for
18instructions specific to this package.  Some packages provide this
19'INSTALL' file but do not implement all of the features documented
20below.  The lack of an optional feature in a given package is not
21necessarily a bug.  More recommendations for GNU packages can be found
22in *note Makefile Conventions: (standards)Makefile Conventions.
23
24   The 'configure' shell script attempts to guess correct values for
25various system-dependent variables used during compilation.  It uses
26those values to create a 'Makefile' in each directory of the package.
27It may also create one or more '.h' files containing system-dependent
28definitions.  Finally, it creates a shell script 'config.status' that
29you can run in the future to recreate the current configuration, and a
30file 'config.log' containing compiler output (useful mainly for
31debugging 'configure').
32
33   It can also use an optional file (typically called 'config.cache' and
34enabled with '--cache-file=config.cache' or simply '-C') that saves the
35results of its tests to speed up reconfiguring.  Caching is disabled by
36default to prevent problems with accidental use of stale cache files.
37
38   If you need to do unusual things to compile the package, please try
39to figure out how 'configure' could check whether to do them, and mail
40diffs or instructions to the address given in the 'README' so they can
41be considered for the next release.  If you are using the cache, and at
42some point 'config.cache' contains results you don't want to keep, you
43may remove or edit it.
44
45   The file 'configure.ac' (or 'configure.in') is used to create
46'configure' by a program called 'autoconf'.  You need 'configure.ac' if
47you want to change it or regenerate 'configure' using a newer version of
48'autoconf'.
49
50   The simplest way to compile this package is:
51
52  1. 'cd' to the directory containing the package's source code and type
53     './configure' to configure the package for your system.
54
55     Running 'configure' might take a while.  While running, it prints
56     some messages telling which features it is checking for.
57
58  2. Type 'make' to compile the package.
59
60  3. Optionally, type 'make check' to run any self-tests that come with
61     the package, generally using the just-built uninstalled binaries.
62
63  4. Type 'make install' to install the programs and any data files and
64     documentation.  When installing into a prefix owned by root, it is
65     recommended that the package be configured and built as a regular
66     user, and only the 'make install' phase executed with root
67     privileges.
68
69  5. Optionally, type 'make installcheck' to repeat any self-tests, but
70     this time using the binaries in their final installed location.
71     This target does not install anything.  Running this target as a
72     regular user, particularly if the prior 'make install' required
73     root privileges, verifies that the installation completed
74     correctly.
75
76  6. You can remove the program binaries and object files from the
77     source code directory by typing 'make clean'.  To also remove the
78     files that 'configure' created (so you can compile the package for
79     a different kind of computer), type 'make distclean'.  There is
80     also a 'make maintainer-clean' target, but that is intended mainly
81     for the package's developers.  If you use it, you may have to get
82     all sorts of other programs in order to regenerate files that came
83     with the distribution.
84
85  7. Often, you can also type 'make uninstall' to remove the installed
86     files again.  In practice, not all packages have tested that
87     uninstallation works correctly, even though it is required by the
88     GNU Coding Standards.
89
90  8. Some packages, particularly those that use Automake, provide 'make
91     distcheck', which can by used by developers to test that all other
92     targets like 'make install' and 'make uninstall' work correctly.
93     This target is generally not run by end users.
94
95Compilers and Options
96=====================
97
98   Some systems require unusual options for compilation or linking that
99the 'configure' script does not know about.  Run './configure --help'
100for details on some of the pertinent environment variables.
101
102   You can give 'configure' initial values for configuration parameters
103by setting variables in the command line or in the environment.  Here is
104an example:
105
106     ./configure CC=c99 CFLAGS=-g LIBS=-lposix
107
108   *Note Defining Variables::, for more details.
109
110Compiling For Multiple Architectures
111====================================
112
113   You can compile the package for more than one kind of computer at the
114same time, by placing the object files for each architecture in their
115own directory.  To do this, you can use GNU 'make'.  'cd' to the
116directory where you want the object files and executables to go and run
117the 'configure' script.  'configure' automatically checks for the source
118code in the directory that 'configure' is in and in '..'.  This is known
119as a "VPATH" build.
120
121   With a non-GNU 'make', it is safer to compile the package for one
122architecture at a time in the source code directory.  After you have
123installed the package for one architecture, use 'make distclean' before
124reconfiguring for another architecture.
125
126   On MacOS X 10.5 and later systems, you can create libraries and
127executables that work on multiple system types--known as "fat" or
128"universal" binaries--by specifying multiple '-arch' options to the
129compiler but only a single '-arch' option to the preprocessor.  Like
130this:
131
132     ./configure CC="gcc -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
133                 CXX="g++ -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
134                 CPP="gcc -E" CXXCPP="g++ -E"
135
136   This is not guaranteed to produce working output in all cases, you
137may have to build one architecture at a time and combine the results
138using the 'lipo' tool if you have problems.
139
140Installation Names
141==================
142
143   By default, 'make install' installs the package's commands under
144'/usr/local/bin', include files under '/usr/local/include', etc.  You
145can specify an installation prefix other than '/usr/local' by giving
146'configure' the option '--prefix=PREFIX', where PREFIX must be an
147absolute file name.
148
149   You can specify separate installation prefixes for
150architecture-specific files and architecture-independent files.  If you
151pass the option '--exec-prefix=PREFIX' to 'configure', the package uses
152PREFIX as the prefix for installing programs and libraries.
153Documentation and other data files still use the regular prefix.
154
155   In addition, if you use an unusual directory layout you can give
156options like '--bindir=DIR' to specify different values for particular
157kinds of files.  Run 'configure --help' for a list of the directories
158you can set and what kinds of files go in them.  In general, the default
159for these options is expressed in terms of '${prefix}', so that
160specifying just '--prefix' will affect all of the other directory
161specifications that were not explicitly provided.
162
163   The most portable way to affect installation locations is to pass the
164correct locations to 'configure'; however, many packages provide one or
165both of the following shortcuts of passing variable assignments to the
166'make install' command line to change installation locations without
167having to reconfigure or recompile.
168
169   The first method involves providing an override variable for each
170affected directory.  For example, 'make install
171prefix=/alternate/directory' will choose an alternate location for all
172directory configuration variables that were expressed in terms of
173'${prefix}'.  Any directories that were specified during 'configure',
174but not in terms of '${prefix}', must each be overridden at install time
175for the entire installation to be relocated.  The approach of makefile
176variable overrides for each directory variable is required by the GNU
177Coding Standards, and ideally causes no recompilation.  However, some
178platforms have known limitations with the semantics of shared libraries
179that end up requiring recompilation when using this method, particularly
180noticeable in packages that use GNU Libtool.
181
182   The second method involves providing the 'DESTDIR' variable.  For
183example, 'make install DESTDIR=/alternate/directory' will prepend
184'/alternate/directory' before all installation names.  The approach of
185'DESTDIR' overrides is not required by the GNU Coding Standards, and
186does not work on platforms that have drive letters.  On the other hand,
187it does better at avoiding recompilation issues, and works well even
188when some directory options were not specified in terms of '${prefix}'
189at 'configure' time.
190
191Optional Features
192=================
193
194   If the package supports it, you can cause programs to be installed
195with an extra prefix or suffix on their names by giving 'configure' the
196option '--program-prefix=PREFIX' or '--program-suffix=SUFFIX'.
197
198   Some packages pay attention to '--enable-FEATURE' options to
199'configure', where FEATURE indicates an optional part of the package.
200They may also pay attention to '--with-PACKAGE' options, where PACKAGE
201is something like 'gnu-as' or 'x' (for the X Window System).  The
202'README' should mention any '--enable-' and '--with-' options that the
203package recognizes.
204
205   For packages that use the X Window System, 'configure' can usually
206find the X include and library files automatically, but if it doesn't,
207you can use the 'configure' options '--x-includes=DIR' and
208'--x-libraries=DIR' to specify their locations.
209
210   Some packages offer the ability to configure how verbose the
211execution of 'make' will be.  For these packages, running './configure
212--enable-silent-rules' sets the default to minimal output, which can be
213overridden with 'make V=1'; while running './configure
214--disable-silent-rules' sets the default to verbose, which can be
215overridden with 'make V=0'.
216
217Particular systems
218==================
219
220   On HP-UX, the default C compiler is not ANSI C compatible.  If GNU CC
221is not installed, it is recommended to use the following options in
222order to use an ANSI C compiler:
223
224     ./configure CC="cc -Ae -D_XOPEN_SOURCE=500"
225
226and if that doesn't work, install pre-built binaries of GCC for HP-UX.
227
228   HP-UX 'make' updates targets which have the same timestamps as their
229prerequisites, which makes it generally unusable when shipped generated
230files such as 'configure' are involved.  Use GNU 'make' instead.
231
232   On OSF/1 a.k.a. Tru64, some versions of the default C compiler cannot
233parse its '<wchar.h>' header file.  The option '-nodtk' can be used as a
234workaround.  If GNU CC is not installed, it is therefore recommended to
235try
236
237     ./configure CC="cc"
238
239and if that doesn't work, try
240
241     ./configure CC="cc -nodtk"
242
243   On Solaris, don't put '/usr/ucb' early in your 'PATH'.  This
244directory contains several dysfunctional programs; working variants of
245these programs are available in '/usr/bin'.  So, if you need '/usr/ucb'
246in your 'PATH', put it _after_ '/usr/bin'.
247
248   On Haiku, software installed for all users goes in '/boot/common',
249not '/usr/local'.  It is recommended to use the following options:
250
251     ./configure --prefix=/boot/common
252
253Specifying the System Type
254==========================
255
256   There may be some features 'configure' cannot figure out
257automatically, but needs to determine by the type of machine the package
258will run on.  Usually, assuming the package is built to be run on the
259_same_ architectures, 'configure' can figure that out, but if it prints
260a message saying it cannot guess the machine type, give it the
261'--build=TYPE' option.  TYPE can either be a short name for the system
262type, such as 'sun4', or a canonical name which has the form:
263
264     CPU-COMPANY-SYSTEM
265
266where SYSTEM can have one of these forms:
267
268     OS
269     KERNEL-OS
270
271   See the file 'config.sub' for the possible values of each field.  If
272'config.sub' isn't included in this package, then this package doesn't
273need to know the machine type.
274
275   If you are _building_ compiler tools for cross-compiling, you should
276use the option '--target=TYPE' to select the type of system they will
277produce code for.
278
279   If you want to _use_ a cross compiler, that generates code for a
280platform different from the build platform, you should specify the
281"host" platform (i.e., that on which the generated programs will
282eventually be run) with '--host=TYPE'.
283
284Sharing Defaults
285================
286
287   If you want to set default values for 'configure' scripts to share,
288you can create a site shell script called 'config.site' that gives
289default values for variables like 'CC', 'cache_file', and 'prefix'.
290'configure' looks for 'PREFIX/share/config.site' if it exists, then
291'PREFIX/etc/config.site' if it exists.  Or, you can set the
292'CONFIG_SITE' environment variable to the location of the site script.
293A warning: not all 'configure' scripts look for a site script.
294
295Defining Variables
296==================
297
298   Variables not defined in a site shell script can be set in the
299environment passed to 'configure'.  However, some packages may run
300configure again during the build, and the customized values of these
301variables may be lost.  In order to avoid this problem, you should set
302them in the 'configure' command line, using 'VAR=value'.  For example:
303
304     ./configure CC=/usr/local2/bin/gcc
305
306causes the specified 'gcc' to be used as the C compiler (unless it is
307overridden in the site shell script).
308
309Unfortunately, this technique does not work for 'CONFIG_SHELL' due to an
310Autoconf limitation.  Until the limitation is lifted, you can use this
311workaround:
312
313     CONFIG_SHELL=/bin/bash ./configure CONFIG_SHELL=/bin/bash
314
315'configure' Invocation
316======================
317
318   'configure' recognizes the following options to control how it
319operates.
320
321'--help'
322'-h'
323     Print a summary of all of the options to 'configure', and exit.
324
325'--help=short'
326'--help=recursive'
327     Print a summary of the options unique to this package's
328     'configure', and exit.  The 'short' variant lists options used only
329     in the top level, while the 'recursive' variant lists options also
330     present in any nested packages.
331
332'--version'
333'-V'
334     Print the version of Autoconf used to generate the 'configure'
335     script, and exit.
336
337'--cache-file=FILE'
338     Enable the cache: use and save the results of the tests in FILE,
339     traditionally 'config.cache'.  FILE defaults to '/dev/null' to
340     disable caching.
341
342'--config-cache'
343'-C'
344     Alias for '--cache-file=config.cache'.
345
346'--quiet'
347'--silent'
348'-q'
349     Do not print messages saying which checks are being made.  To
350     suppress all normal output, redirect it to '/dev/null' (any error
351     messages will still be shown).
352
353'--srcdir=DIR'
354     Look for the package's source code in directory DIR.  Usually
355     'configure' can determine that directory automatically.
356
357'--prefix=DIR'
358     Use DIR as the installation prefix.  *note Installation Names:: for
359     more details, including other options available for fine-tuning the
360     installation locations.
361
362'--no-create'
363'-n'
364     Run the configure checks, but stop before creating any output
365     files.
366
367'configure' also accepts some other, not widely useful, options.  Run
368'configure --help' for more details.
369