configure.html revision 1.1.1.1.8.1
1<html lang="en">
2<head>
3<title>Installing GCC: Configuration</title>
4<meta http-equiv="Content-Type" content="text/html">
5<meta name="description" content="Installing GCC: Configuration">
6<meta name="generator" content="makeinfo 4.12">
7<link title="Top" rel="top" href="#Top">
8<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
9<!--
10Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997,
111998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
122009, 2010, 2011 Free Software Foundation, Inc.
13
14   Permission is granted to copy, distribute and/or modify this document
15under the terms of the GNU Free Documentation License, Version 1.2 or
16any later version published by the Free Software Foundation; with no
17Invariant Sections, the Front-Cover texts being (a) (see below), and
18with the Back-Cover Texts being (b) (see below).  A copy of the
19license is included in the section entitled "GNU Free Documentation License".
20
21(a) The FSF's Front-Cover Text is:
22
23     A GNU Manual
24
25(b) The FSF's Back-Cover Text is:
26
27     You have freedom to copy and modify this GNU Manual, like GNU
28     software.  Copies published by the Free Software Foundation raise
29     funds for GNU development.-->
30<meta http-equiv="Content-Style-Type" content="text/css">
31<style type="text/css"><!--
32  pre.display { font-family:inherit }
33  pre.format  { font-family:inherit }
34  pre.smalldisplay { font-family:inherit; font-size:smaller }
35  pre.smallformat  { font-family:inherit; font-size:smaller }
36  pre.smallexample { font-size:smaller }
37  pre.smalllisp    { font-size:smaller }
38  span.sc    { font-variant:small-caps }
39  span.roman { font-family:serif; font-weight:normal; } 
40  span.sansserif { font-family:sans-serif; font-weight:normal; } 
41--></style>
42</head>
43<body>
44<h1 class="settitle">Installing GCC: Configuration</h1>
45<a name="index-Configuration-1"></a><a name="index-Installing-GCC_003a-Configuration-2"></a>
46Like most GNU software, GCC must be configured before it can be built. 
47This document describes the recommended configuration procedure
48for both native and cross targets.
49
50   <p>We use <var>srcdir</var> to refer to the toplevel source directory for
51GCC; we use <var>objdir</var> to refer to the toplevel build/object directory.
52
53   <p>If you obtained the sources via SVN, <var>srcdir</var> must refer to the top
54<samp><span class="file">gcc</span></samp> directory, the one where the <samp><span class="file">MAINTAINERS</span></samp> file can be
55found, and not its <samp><span class="file">gcc</span></samp> subdirectory, otherwise the build will fail.
56
57   <p>If either <var>srcdir</var> or <var>objdir</var> is located on an automounted NFS
58file system, the shell's built-in <samp><span class="command">pwd</span></samp> command will return
59temporary pathnames.  Using these can lead to various sorts of build
60problems.  To avoid this issue, set the <samp><span class="env">PWDCMD</span></samp> environment
61variable to an automounter-aware <samp><span class="command">pwd</span></samp> command, e.g.,
62<samp><span class="command">pawd</span></samp> or &lsquo;<samp><span class="samp">amq -w</span></samp>&rsquo;, during the configuration and build
63phases.
64
65   <p>First, we <strong>highly</strong> recommend that GCC be built into a
66separate directory from the sources which does <strong>not</strong> reside
67within the source tree.  This is how we generally build GCC; building
68where <var>srcdir</var> == <var>objdir</var> should still work, but doesn't
69get extensive testing; building where <var>objdir</var> is a subdirectory
70of <var>srcdir</var> is unsupported.
71
72   <p>If you have previously built GCC in the same directory for a
73different target machine, do &lsquo;<samp><span class="samp">make distclean</span></samp>&rsquo; to delete all files
74that might be invalid.  One of the files this deletes is <samp><span class="file">Makefile</span></samp>;
75if &lsquo;<samp><span class="samp">make distclean</span></samp>&rsquo; complains that <samp><span class="file">Makefile</span></samp> does not exist
76or issues a message like &ldquo;don't know how to make distclean&rdquo; it probably
77means that the directory is already suitably clean.  However, with the
78recommended method of building in a separate <var>objdir</var>, you should
79simply use a different <var>objdir</var> for each target.
80
81   <p>Second, when configuring a native system, either <samp><span class="command">cc</span></samp> or
82<samp><span class="command">gcc</span></samp> must be in your path or you must set <samp><span class="env">CC</span></samp> in
83your environment before running configure.  Otherwise the configuration
84scripts may fail.
85
86   <p>To configure GCC:
87
88<pre class="smallexample">        % mkdir <var>objdir</var>
89        % cd <var>objdir</var>
90        % <var>srcdir</var>/configure [<var>options</var>] [<var>target</var>]
91</pre>
92   <h3 class="heading"><a name="TOC0"></a>Distributor options</h3>
93
94<p>If you will be distributing binary versions of GCC, with modifications
95to the source code, you should use the options described in this
96section to make clear that your version contains modifications.
97
98     <dl>
99<dt><code>--with-pkgversion=</code><var>version</var><dd>Specify a string that identifies your package.  You may wish
100to include a build number or build date.  This version string will be
101included in the output of <samp><span class="command">gcc --version</span></samp>.  This suffix does
102not replace the default version string, only the &lsquo;<samp><span class="samp">GCC</span></samp>&rsquo; part.
103
104     <p>The default value is &lsquo;<samp><span class="samp">GCC</span></samp>&rsquo;.
105
106     <br><dt><code>--with-bugurl=</code><var>url</var><dd>Specify the URL that users should visit if they wish to report a bug. 
107You are of course welcome to forward bugs reported to you to the FSF,
108if you determine that they are not bugs in your modifications.
109
110     <p>The default value refers to the FSF's GCC bug tracker.
111
112   </dl>
113
114<h3 class="heading"><a name="TOC1"></a>Target specification</h3>
115
116     <ul>
117<li>GCC has code to correctly determine the correct value for <var>target</var>
118for nearly all native systems.  Therefore, we highly recommend you do
119not provide a configure target when configuring a native compiler.
120
121     <li><var>target</var> must be specified as <samp><span class="option">--target=</span><var>target</var></samp>
122when configuring a cross compiler; examples of valid targets would be
123m68k-elf, sh-elf, etc.
124
125     <li>Specifying just <var>target</var> instead of <samp><span class="option">--target=</span><var>target</var></samp>
126implies that the host defaults to <var>target</var>. 
127</ul>
128
129<h3 class="heading"><a name="TOC2"></a>Options specification</h3>
130
131<p>Use <var>options</var> to override several configure time options for
132GCC.  A list of supported <var>options</var> follows; &lsquo;<samp><span class="samp">configure
133--help</span></samp>&rsquo; may list other options, but those not listed below may not
134work and should not normally be used.
135
136   <p>Note that each <samp><span class="option">--enable</span></samp> option has a corresponding
137<samp><span class="option">--disable</span></samp> option and that each <samp><span class="option">--with</span></samp> option has a
138corresponding <samp><span class="option">--without</span></samp> option.
139
140     <dl>
141<dt><code>--prefix=</code><var>dirname</var><dd>Specify the toplevel installation
142directory.  This is the recommended way to install the tools into a directory
143other than the default.  The toplevel installation directory defaults to
144<samp><span class="file">/usr/local</span></samp>.
145
146     <p>We <strong>highly</strong> recommend against <var>dirname</var> being the same or a
147subdirectory of <var>objdir</var> or vice versa.  If specifying a directory
148beneath a user's home directory tree, some shells will not expand
149<var>dirname</var> correctly if it contains the &lsquo;<samp><span class="samp">~</span></samp>&rsquo; metacharacter; use
150<samp><span class="env">$HOME</span></samp> instead.
151
152     <p>The following standard <samp><span class="command">autoconf</span></samp> options are supported.  Normally you
153should not need to use these options.
154          <dl>
155<dt><code>--exec-prefix=</code><var>dirname</var><dd>Specify the toplevel installation directory for architecture-dependent
156files.  The default is <samp><var>prefix</var></samp>.
157
158          <br><dt><code>--bindir=</code><var>dirname</var><dd>Specify the installation directory for the executables called by users
159(such as <samp><span class="command">gcc</span></samp> and <samp><span class="command">g++</span></samp>).  The default is
160<samp><var>exec-prefix</var><span class="file">/bin</span></samp>.
161
162          <br><dt><code>--libdir=</code><var>dirname</var><dd>Specify the installation directory for object code libraries and
163internal data files of GCC.  The default is <samp><var>exec-prefix</var><span class="file">/lib</span></samp>.
164
165          <br><dt><code>--libexecdir=</code><var>dirname</var><dd>Specify the installation directory for internal executables of GCC. 
166The default is <samp><var>exec-prefix</var><span class="file">/libexec</span></samp>.
167
168          <br><dt><code>--with-slibdir=</code><var>dirname</var><dd>Specify the installation directory for the shared libgcc library.  The
169default is <samp><var>libdir</var></samp>.
170
171          <br><dt><code>--datarootdir=</code><var>dirname</var><dd>Specify the root of the directory tree for read-only architecture-independent
172data files referenced by GCC.  The default is <samp><var>prefix</var><span class="file">/share</span></samp>.
173
174          <br><dt><code>--infodir=</code><var>dirname</var><dd>Specify the installation directory for documentation in info format. 
175The default is <samp><var>datarootdir</var><span class="file">/info</span></samp>.
176
177          <br><dt><code>--datadir=</code><var>dirname</var><dd>Specify the installation directory for some architecture-independent
178data files referenced by GCC.  The default is <samp><var>datarootdir</var></samp>.
179
180          <br><dt><code>--docdir=</code><var>dirname</var><dd>Specify the installation directory for documentation files (other
181than Info) for GCC.  The default is <samp><var>datarootdir</var><span class="file">/doc</span></samp>.
182
183          <br><dt><code>--htmldir=</code><var>dirname</var><dd>Specify the installation directory for HTML documentation files. 
184The default is <samp><var>docdir</var></samp>.
185
186          <br><dt><code>--pdfdir=</code><var>dirname</var><dd>Specify the installation directory for PDF documentation files. 
187The default is <samp><var>docdir</var></samp>.
188
189          <br><dt><code>--mandir=</code><var>dirname</var><dd>Specify the installation directory for manual pages.  The default is
190<samp><var>datarootdir</var><span class="file">/man</span></samp>.  (Note that the manual pages are only extracts
191from the full GCC manuals, which are provided in Texinfo format.  The manpages
192are derived by an automatic conversion process from parts of the full
193manual.)
194
195          <br><dt><code>--with-gxx-include-dir=</code><var>dirname</var><dd>Specify
196the installation directory for G++ header files.  The default depends
197on other configuration options, and differs between cross and native
198configurations.
199
200     </dl>
201
202     <br><dt><code>--program-prefix=</code><var>prefix</var><dd>GCC supports some transformations of the names of its programs when
203installing them.  This option prepends <var>prefix</var> to the names of
204programs to install in <var>bindir</var> (see above).  For example, specifying
205<samp><span class="option">--program-prefix=foo-</span></samp> would result in &lsquo;<samp><span class="samp">gcc</span></samp>&rsquo;
206being installed as <samp><span class="file">/usr/local/bin/foo-gcc</span></samp>.
207
208     <br><dt><code>--program-suffix=</code><var>suffix</var><dd>Appends <var>suffix</var> to the names of programs to install in <var>bindir</var>
209(see above).  For example, specifying <samp><span class="option">--program-suffix=-3.1</span></samp>
210would result in &lsquo;<samp><span class="samp">gcc</span></samp>&rsquo; being installed as
211<samp><span class="file">/usr/local/bin/gcc-3.1</span></samp>.
212
213     <br><dt><code>--program-transform-name=</code><var>pattern</var><dd>Applies the &lsquo;<samp><span class="samp">sed</span></samp>&rsquo; script <var>pattern</var> to be applied to the names
214of programs to install in <var>bindir</var> (see above).  <var>pattern</var> has to
215consist of one or more basic &lsquo;<samp><span class="samp">sed</span></samp>&rsquo; editing commands, separated by
216semicolons.  For example, if you want the &lsquo;<samp><span class="samp">gcc</span></samp>&rsquo; program name to be
217transformed to the installed program <samp><span class="file">/usr/local/bin/myowngcc</span></samp> and
218the &lsquo;<samp><span class="samp">g++</span></samp>&rsquo; program name to be transformed to
219<samp><span class="file">/usr/local/bin/gspecial++</span></samp> without changing other program names,
220you could use the pattern
221<samp><span class="option">--program-transform-name='s/^gcc$/myowngcc/; s/^g++$/gspecial++/'</span></samp>
222to achieve this effect.
223
224     <p>All three options can be combined and used together, resulting in more
225complex conversion patterns.  As a basic rule, <var>prefix</var> (and
226<var>suffix</var>) are prepended (appended) before further transformations
227can happen with a special transformation script <var>pattern</var>.
228
229     <p>As currently implemented, this option only takes effect for native
230builds; cross compiler binaries' names are not transformed even when a
231transformation is explicitly asked for by one of these options.
232
233     <p>For native builds, some of the installed programs are also installed
234with the target alias in front of their name, as in
235&lsquo;<samp><span class="samp">i686-pc-linux-gnu-gcc</span></samp>&rsquo;.  All of the above transformations happen
236before the target alias is prepended to the name&mdash;so, specifying
237<samp><span class="option">--program-prefix=foo-</span></samp> and <samp><span class="option">program-suffix=-3.1</span></samp>, the
238resulting binary would be installed as
239<samp><span class="file">/usr/local/bin/i686-pc-linux-gnu-foo-gcc-3.1</span></samp>.
240
241     <p>As a last shortcoming, none of the installed Ada programs are
242transformed yet, which will be fixed in some time.
243
244     <br><dt><code>--with-local-prefix=</code><var>dirname</var><dd>Specify the
245installation directory for local include files.  The default is
246<samp><span class="file">/usr/local</span></samp>.  Specify this option if you want the compiler to
247search directory <samp><var>dirname</var><span class="file">/include</span></samp> for locally installed
248header files <em>instead</em> of <samp><span class="file">/usr/local/include</span></samp>.
249
250     <p>You should specify <samp><span class="option">--with-local-prefix</span></samp> <strong>only</strong> if your
251site has a different convention (not <samp><span class="file">/usr/local</span></samp>) for where to put
252site-specific files.
253
254     <p>The default value for <samp><span class="option">--with-local-prefix</span></samp> is <samp><span class="file">/usr/local</span></samp>
255regardless of the value of <samp><span class="option">--prefix</span></samp>.  Specifying
256<samp><span class="option">--prefix</span></samp> has no effect on which directory GCC searches for
257local header files.  This may seem counterintuitive, but actually it is
258logical.
259
260     <p>The purpose of <samp><span class="option">--prefix</span></samp> is to specify where to <em>install
261GCC</em>.  The local header files in <samp><span class="file">/usr/local/include</span></samp>&mdash;if you put
262any in that directory&mdash;are not part of GCC.  They are part of other
263programs&mdash;perhaps many others.  (GCC installs its own header files in
264another directory which is based on the <samp><span class="option">--prefix</span></samp> value.)
265
266     <p>Both the local-prefix include directory and the GCC-prefix include
267directory are part of GCC's &ldquo;system include&rdquo; directories.  Although these
268two directories are not fixed, they need to be searched in the proper
269order for the correct processing of the include_next directive.  The
270local-prefix include directory is searched before the GCC-prefix
271include directory.  Another characteristic of system include directories
272is that pedantic warnings are turned off for headers in these directories.
273
274     <p>Some autoconf macros add <samp><span class="option">-I </span><var>directory</var></samp> options to the
275compiler command line, to ensure that directories containing installed
276packages' headers are searched.  When <var>directory</var> is one of GCC's
277system include directories, GCC will ignore the option so that system
278directories continue to be processed in the correct order.  This
279may result in a search order different from what was specified but the
280directory will still be searched.
281
282     <p>GCC automatically searches for ordinary libraries using
283<samp><span class="env">GCC_EXEC_PREFIX</span></samp>.  Thus, when the same installation prefix is
284used for both GCC and packages, GCC will automatically search for
285both headers and libraries.  This provides a configuration that is
286easy to use.  GCC behaves in a manner similar to that when it is
287installed as a system compiler in <samp><span class="file">/usr</span></samp>.
288
289     <p>Sites that need to install multiple versions of GCC may not want to
290use the above simple configuration.  It is possible to use the
291<samp><span class="option">--program-prefix</span></samp>, <samp><span class="option">--program-suffix</span></samp> and
292<samp><span class="option">--program-transform-name</span></samp> options to install multiple versions
293into a single directory, but it may be simpler to use different prefixes
294and the <samp><span class="option">--with-local-prefix</span></samp> option to specify the location of the
295site-specific files for each version.  It will then be necessary for
296users to specify explicitly the location of local site libraries
297(e.g., with <samp><span class="env">LIBRARY_PATH</span></samp>).
298
299     <p>The same value can be used for both <samp><span class="option">--with-local-prefix</span></samp> and
300<samp><span class="option">--prefix</span></samp> provided it is not <samp><span class="file">/usr</span></samp>.  This can be used
301to avoid the default search of <samp><span class="file">/usr/local/include</span></samp>.
302
303     <p><strong>Do not</strong> specify <samp><span class="file">/usr</span></samp> as the <samp><span class="option">--with-local-prefix</span></samp>! 
304The directory you use for <samp><span class="option">--with-local-prefix</span></samp> <strong>must not</strong>
305contain any of the system's standard header files.  If it did contain
306them, certain programs would be miscompiled (including GNU Emacs, on
307certain targets), because this would override and nullify the header
308file corrections made by the <samp><span class="command">fixincludes</span></samp> script.
309
310     <p>Indications are that people who use this option use it based on mistaken
311ideas of what it is for.  People use it as if it specified where to
312install part of GCC.  Perhaps they make this assumption because
313installing GCC creates the directory.
314
315     <br><dt><code>--enable-shared[=</code><var>package</var><code>[,...]]</code><dd>Build shared versions of libraries, if shared libraries are supported on
316the target platform.  Unlike GCC 2.95.x and earlier, shared libraries
317are enabled by default on all platforms that support shared libraries.
318
319     <p>If a list of packages is given as an argument, build shared libraries
320only for the listed packages.  For other packages, only static libraries
321will be built.  Package names currently recognized in the GCC tree are
322&lsquo;<samp><span class="samp">libgcc</span></samp>&rsquo; (also known as &lsquo;<samp><span class="samp">gcc</span></samp>&rsquo;), &lsquo;<samp><span class="samp">libstdc++</span></samp>&rsquo; (not
323&lsquo;<samp><span class="samp">libstdc++-v3</span></samp>&rsquo;), &lsquo;<samp><span class="samp">libffi</span></samp>&rsquo;, &lsquo;<samp><span class="samp">zlib</span></samp>&rsquo;, &lsquo;<samp><span class="samp">boehm-gc</span></samp>&rsquo;,
324&lsquo;<samp><span class="samp">ada</span></samp>&rsquo;, &lsquo;<samp><span class="samp">libada</span></samp>&rsquo;, &lsquo;<samp><span class="samp">libjava</span></samp>&rsquo; and &lsquo;<samp><span class="samp">libobjc</span></samp>&rsquo;. 
325Note &lsquo;<samp><span class="samp">libiberty</span></samp>&rsquo; does not support shared libraries at all.
326
327     <p>Use <samp><span class="option">--disable-shared</span></samp> to build only static libraries.  Note that
328<samp><span class="option">--disable-shared</span></samp> does not accept a list of package names as
329argument, only <samp><span class="option">--enable-shared</span></samp> does.
330
331     <br><dt><code><a name="with_002dgnu_002das"></a>--with-gnu-as</code><dd>Specify that the compiler should assume that the
332assembler it finds is the GNU assembler.  However, this does not modify
333the rules to find an assembler and will result in confusion if the
334assembler found is not actually the GNU assembler.  (Confusion may also
335result if the compiler finds the GNU assembler but has not been
336configured with <samp><span class="option">--with-gnu-as</span></samp>.)  If you have more than one
337assembler installed on your system, you may want to use this option in
338connection with <samp><span class="option">--with-as=</span><var>pathname</var></samp> or
339<samp><span class="option">--with-build-time-tools=</span><var>pathname</var></samp>.
340
341     <p>The following systems are the only ones where it makes a difference
342whether you use the GNU assembler.  On any other system,
343<samp><span class="option">--with-gnu-as</span></samp> has no effect.
344
345          <ul>
346<li>&lsquo;<samp><span class="samp">hppa1.0-</span><var>any</var><span class="samp">-</span><var>any</var></samp>&rsquo;
347<li>&lsquo;<samp><span class="samp">hppa1.1-</span><var>any</var><span class="samp">-</span><var>any</var></samp>&rsquo;
348<li>&lsquo;<samp><span class="samp">sparc-sun-solaris2.</span><var>any</var></samp>&rsquo;
349<li>&lsquo;<samp><span class="samp">sparc64-</span><var>any</var><span class="samp">-solaris2.</span><var>any</var></samp>&rsquo;
350</ul>
351
352     <br><dt><code><a name="with_002das"></a>--with-as=</code><var>pathname</var><dd>Specify that the compiler should use the assembler pointed to by
353<var>pathname</var>, rather than the one found by the standard rules to find
354an assembler, which are:
355          <ul>
356<li>Unless GCC is being built with a cross compiler, check the
357<samp><var>libexec</var><span class="file">/gcc/</span><var>target</var><span class="file">/</span><var>version</var></samp> directory. 
358<var>libexec</var> defaults to <samp><var>exec-prefix</var><span class="file">/libexec</span></samp>;
359<var>exec-prefix</var> defaults to <var>prefix</var>, which
360defaults to <samp><span class="file">/usr/local</span></samp> unless overridden by the
361<samp><span class="option">--prefix=</span><var>pathname</var></samp> switch described above.  <var>target</var>
362is the target system triple, such as &lsquo;<samp><span class="samp">sparc-sun-solaris2.7</span></samp>&rsquo;, and
363<var>version</var> denotes the GCC version, such as 3.0.
364
365          <li>If the target system is the same that you are building on, check
366operating system specific directories (e.g. <samp><span class="file">/usr/ccs/bin</span></samp> on
367Sun Solaris 2).
368
369          <li>Check in the <samp><span class="env">PATH</span></samp> for a tool whose name is prefixed by the
370target system triple.
371
372          <li>Check in the <samp><span class="env">PATH</span></samp> for a tool whose name is not prefixed by the
373target system triple, if the host and target system triple are
374the same (in other words, we use a host tool if it can be used for
375the target as well). 
376</ul>
377
378     <p>You may want to use <samp><span class="option">--with-as</span></samp> if no assembler
379is installed in the directories listed above, or if you have multiple
380assemblers installed and want to choose one that is not found by the
381above rules.
382
383     <br><dt><code><a name="with_002dgnu_002dld"></a>--with-gnu-ld</code><dd>Same as <a href="#with-gnu-as"><samp><span class="option">--with-gnu-as</span></samp></a>
384but for the linker.
385
386     <br><dt><code>--with-ld=</code><var>pathname</var><dd>Same as <a href="#with-as"><samp><span class="option">--with-as</span></samp></a>
387but for the linker.
388
389     <br><dt><code>--with-stabs</code><dd>Specify that stabs debugging
390information should be used instead of whatever format the host normally
391uses.  Normally GCC uses the same debug format as the host system.
392
393     <p>On MIPS based systems and on Alphas, you must specify whether you want
394GCC to create the normal ECOFF debugging format, or to use BSD-style
395stabs passed through the ECOFF symbol table.  The normal ECOFF debug
396format cannot fully handle languages other than C.  BSD stabs format can
397handle other languages, but it only works with the GNU debugger GDB.
398
399     <p>Normally, GCC uses the ECOFF debugging format by default; if you
400prefer BSD stabs, specify <samp><span class="option">--with-stabs</span></samp> when you configure GCC.
401
402     <p>No matter which default you choose when you configure GCC, the user
403can use the <samp><span class="option">-gcoff</span></samp> and <samp><span class="option">-gstabs+</span></samp> options to specify explicitly
404the debug format for a particular compilation.
405
406     <p><samp><span class="option">--with-stabs</span></samp> is meaningful on the ISC system on the 386, also, if
407<samp><span class="option">--with-gas</span></samp> is used.  It selects use of stabs debugging
408information embedded in COFF output.  This kind of debugging information
409supports C++ well; ordinary COFF debugging information does not.
410
411     <p><samp><span class="option">--with-stabs</span></samp> is also meaningful on 386 systems running SVR4.  It
412selects use of stabs debugging information embedded in ELF output.  The
413C++ compiler currently (2.6.0) does not support the DWARF debugging
414information normally used on 386 SVR4 platforms; stabs provide a
415workable alternative.  This requires gas and gdb, as the normal SVR4
416tools can not generate or interpret stabs.
417
418     <br><dt><code>--disable-multilib</code><dd>Specify that multiple target
419libraries to support different target variants, calling
420conventions, etc. should not be built.  The default is to build a
421predefined set of them.
422
423     <p>Some targets provide finer-grained control over which multilibs are built
424(e.g., <samp><span class="option">--disable-softfloat</span></samp>):
425          <dl>
426<dt><code>arc-*-elf*</code><dd>biendian.
427
428          <br><dt><code>arm-*-*</code><dd>fpu, 26bit, underscore, interwork, biendian, nofmult.
429
430          <br><dt><code>m68*-*-*</code><dd>softfloat, m68881, m68000, m68020.
431
432          <br><dt><code>mips*-*-*</code><dd>single-float, biendian, softfloat.
433
434          <br><dt><code>powerpc*-*-*, rs6000*-*-*</code><dd>aix64, pthread, softfloat, powercpu, powerpccpu, powerpcos, biendian,
435sysv, aix.
436
437     </dl>
438
439     <br><dt><code>--with-multilib-list=</code><var>list</var><dt><code>--without-multilib-list</code><dd>Specify what multilibs to build. 
440Currently only implemented for sh*-*-*.
441
442     <p><var>list</var> is a comma separated list of CPU names.  These must be of the
443form <code>sh*</code> or <code>m*</code> (in which case they match the compiler option
444for that processor).  The list should not contain any endian options -
445these are handled by <samp><span class="option">--with-endian</span></samp>.
446
447     <p>If <var>list</var> is empty, then there will be no multilibs for extra
448processors.  The multilib for the secondary endian remains enabled.
449
450     <p>As a special case, if an entry in the list starts with a <code>!</code>
451(exclamation point), then it is added to the list of excluded multilibs. 
452Entries of this sort should be compatible with &lsquo;<samp><span class="samp">MULTILIB_EXCLUDES</span></samp>&rsquo;
453(once the leading <code>!</code> has been stripped).
454
455     <p>If <samp><span class="option">--with-multilib-list</span></samp> is not given, then a default set of
456multilibs is selected based on the value of <samp><span class="option">--target</span></samp>.  This is
457usually the complete set of libraries, but some targets imply a more
458specialized subset.
459
460     <p>Example 1: to configure a compiler for SH4A only, but supporting both
461endians, with little endian being the default:
462     <pre class="smallexample">          --with-cpu=sh4a --with-endian=little,big --with-multilib-list=
463</pre>
464     <p>Example 2: to configure a compiler for both SH4A and SH4AL-DSP, but with
465only little endian SH4AL:
466     <pre class="smallexample">          --with-cpu=sh4a --with-endian=little,big --with-multilib-list=sh4al,!mb/m4al
467</pre>
468     <br><dt><code>--with-endian=</code><var>endians</var><dd>Specify what endians to use. 
469Currently only implemented for sh*-*-*.
470
471     <p><var>endians</var> may be one of the following:
472          <dl>
473<dt><code>big</code><dd>Use big endian exclusively. 
474<br><dt><code>little</code><dd>Use little endian exclusively. 
475<br><dt><code>big,little</code><dd>Use big endian by default.  Provide a multilib for little endian. 
476<br><dt><code>little,big</code><dd>Use little endian by default.  Provide a multilib for big endian. 
477</dl>
478
479     <br><dt><code>--enable-threads</code><dd>Specify that the target
480supports threads.  This affects the Objective-C compiler and runtime
481library, and exception handling for other languages like C++ and Java. 
482On some systems, this is the default.
483
484     <p>In general, the best (and, in many cases, the only known) threading
485model available will be configured for use.  Beware that on some
486systems, GCC has not been taught what threading models are generally
487available for the system.  In this case, <samp><span class="option">--enable-threads</span></samp> is an
488alias for <samp><span class="option">--enable-threads=single</span></samp>.
489
490     <br><dt><code>--disable-threads</code><dd>Specify that threading support should be disabled for the system. 
491This is an alias for <samp><span class="option">--enable-threads=single</span></samp>.
492
493     <br><dt><code>--enable-threads=</code><var>lib</var><dd>Specify that
494<var>lib</var> is the thread support library.  This affects the Objective-C
495compiler and runtime library, and exception handling for other languages
496like C++ and Java.  The possibilities for <var>lib</var> are:
497
498          <dl>
499<dt><code>aix</code><dd>AIX thread support. 
500<br><dt><code>dce</code><dd>DCE thread support. 
501<br><dt><code>gnat</code><dd>Ada tasking support.  For non-Ada programs, this setting is equivalent
502to &lsquo;<samp><span class="samp">single</span></samp>&rsquo;.  When used in conjunction with the Ada run time, it
503causes GCC to use the same thread primitives as Ada uses.  This option
504is necessary when using both Ada and the back end exception handling,
505which is the default for most Ada targets. 
506<br><dt><code>mach</code><dd>Generic MACH thread support, known to work on NeXTSTEP.  (Please note
507that the file needed to support this configuration, <samp><span class="file">gthr-mach.h</span></samp>, is
508missing and thus this setting will cause a known bootstrap failure.) 
509<br><dt><code>no</code><dd>This is an alias for &lsquo;<samp><span class="samp">single</span></samp>&rsquo;. 
510<br><dt><code>posix</code><dd>Generic POSIX/Unix98 thread support. 
511<br><dt><code>posix95</code><dd>Generic POSIX/Unix95 thread support. 
512<br><dt><code>rtems</code><dd>RTEMS thread support. 
513<br><dt><code>single</code><dd>Disable thread support, should work for all platforms. 
514<br><dt><code>solaris</code><dd>Sun Solaris 2/Unix International thread support.  Only use this if you
515really need to use this legacy API instead of the default, &lsquo;<samp><span class="samp">posix</span></samp>&rsquo;. 
516<br><dt><code>vxworks</code><dd>VxWorks thread support. 
517<br><dt><code>win32</code><dd>Microsoft Win32 API thread support. 
518<br><dt><code>nks</code><dd>Novell Kernel Services thread support. 
519</dl>
520
521     <br><dt><code>--enable-tls</code><dd>Specify that the target supports TLS (Thread Local Storage).  Usually
522configure can correctly determine if TLS is supported.  In cases where
523it guesses incorrectly, TLS can be explicitly enabled or disabled with
524<samp><span class="option">--enable-tls</span></samp> or <samp><span class="option">--disable-tls</span></samp>.  This can happen if
525the assembler supports TLS but the C library does not, or if the
526assumptions made by the configure test are incorrect.
527
528     <br><dt><code>--disable-tls</code><dd>Specify that the target does not support TLS. 
529This is an alias for <samp><span class="option">--enable-tls=no</span></samp>.
530
531     <br><dt><code>--with-cpu=</code><var>cpu</var><dt><code>--with-cpu-32=</code><var>cpu</var><dt><code>--with-cpu-64=</code><var>cpu</var><dd>Specify which cpu variant the compiler should generate code for by default. 
532<var>cpu</var> will be used as the default value of the <samp><span class="option">-mcpu=</span></samp> switch. 
533This option is only supported on some targets, including ARM, i386, M68k,
534PowerPC, and SPARC.  The <samp><span class="option">--with-cpu-32</span></samp> and
535<samp><span class="option">--with-cpu-64</span></samp> options specify separate default CPUs for
53632-bit and 64-bit modes; these options are only supported for i386,
537x86-64 and PowerPC.
538
539     <br><dt><code>--with-schedule=</code><var>cpu</var><dt><code>--with-arch=</code><var>cpu</var><dt><code>--with-arch-32=</code><var>cpu</var><dt><code>--with-arch-64=</code><var>cpu</var><dt><code>--with-tune=</code><var>cpu</var><dt><code>--with-tune-32=</code><var>cpu</var><dt><code>--with-tune-64=</code><var>cpu</var><dt><code>--with-abi=</code><var>abi</var><dt><code>--with-fpu=</code><var>type</var><dt><code>--with-float=</code><var>type</var><dd>These configure options provide default values for the <samp><span class="option">-mschedule=</span></samp>,
540<samp><span class="option">-march=</span></samp>, <samp><span class="option">-mtune=</span></samp>, <samp><span class="option">-mabi=</span></samp>, and <samp><span class="option">-mfpu=</span></samp>
541options and for <samp><span class="option">-mhard-float</span></samp> or <samp><span class="option">-msoft-float</span></samp>.  As with
542<samp><span class="option">--with-cpu</span></samp>, which switches will be accepted and acceptable values
543of the arguments depend on the target.
544
545     <br><dt><code>--with-mode=</code><var>mode</var><dd>Specify if the compiler should default to <samp><span class="option">-marm</span></samp> or <samp><span class="option">-mthumb</span></samp>. 
546This option is only supported on ARM targets.
547
548     <br><dt><code>--with-fpmath=sse</code><dd>Specify if the compiler should default to <samp><span class="option">-msse2</span></samp> and
549<samp><span class="option">-mfpmath=sse</span></samp>.  This option is only supported on i386 and
550x86-64 targets.
551
552     <br><dt><code>--with-divide=</code><var>type</var><dd>Specify how the compiler should generate code for checking for
553division by zero.  This option is only supported on the MIPS target. 
554The possibilities for <var>type</var> are:
555          <dl>
556<dt><code>traps</code><dd>Division by zero checks use conditional traps (this is the default on
557systems that support conditional traps). 
558<br><dt><code>breaks</code><dd>Division by zero checks use the break instruction. 
559</dl>
560
561     <!-- If you make -with-llsc the default for additional targets, -->
562     <!-- update the -with-llsc description in the MIPS section below. -->
563     <br><dt><code>--with-llsc</code><dd>On MIPS targets, make <samp><span class="option">-mllsc</span></samp> the default when no
564<samp><span class="option">-mno-llsc</span></samp> option is passed.  This is the default for
565Linux-based targets, as the kernel will emulate them if the ISA does
566not provide them.
567
568     <br><dt><code>--without-llsc</code><dd>On MIPS targets, make <samp><span class="option">-mno-llsc</span></samp> the default when no
569<samp><span class="option">-mllsc</span></samp> option is passed.
570
571     <br><dt><code>--with-synci</code><dd>On MIPS targets, make <samp><span class="option">-msynci</span></samp> the default when no
572<samp><span class="option">-mno-synci</span></samp> option is passed.
573
574     <br><dt><code>--without-synci</code><dd>On MIPS targets, make <samp><span class="option">-mno-synci</span></samp> the default when no
575<samp><span class="option">-msynci</span></samp> option is passed.  This is the default.
576
577     <br><dt><code>--with-mips-plt</code><dd>On MIPS targets, make use of copy relocations and PLTs. 
578These features are extensions to the traditional
579SVR4-based MIPS ABIs and require support from GNU binutils
580and the runtime C library.
581
582     <br><dt><code>--enable-__cxa_atexit</code><dd>Define if you want to use __cxa_atexit, rather than atexit, to
583register C++ destructors for local statics and global objects. 
584This is essential for fully standards-compliant handling of
585destructors, but requires __cxa_atexit in libc.  This option is currently
586only available on systems with GNU libc.  When enabled, this will cause
587<samp><span class="option">-fuse-cxa-atexit</span></samp> to be passed by default.
588
589     <br><dt><code>--enable-target-optspace</code><dd>Specify that target
590libraries should be optimized for code space instead of code speed. 
591This is the default for the m32r platform.
592
593     <br><dt><code>--with-cpp-install-dir=</code><var>dirname</var><dd>Specify that the user visible <samp><span class="command">cpp</span></samp> program should be installed
594in <samp><var>prefix</var><span class="file">/</span><var>dirname</var><span class="file">/cpp</span></samp>, in addition to <var>bindir</var>.
595
596     <br><dt><code>--enable-comdat</code><dd>Enable COMDAT group support.  This is primarily used to override the
597automatically detected value.
598
599     <br><dt><code>--enable-initfini-array</code><dd>Force the use of sections <code>.init_array</code> and <code>.fini_array</code>
600(instead of <code>.init</code> and <code>.fini</code>) for constructors and
601destructors.  Option <samp><span class="option">--disable-initfini-array</span></samp> has the
602opposite effect.  If neither option is specified, the configure script
603will try to guess whether the <code>.init_array</code> and
604<code>.fini_array</code> sections are supported and, if they are, use them.
605
606     <br><dt><code>--enable-build-with-cxx</code><dd>Build GCC using a C++ compiler rather than a C compiler.  This is an
607experimental option which may become the default in a later release.
608
609     <br><dt><code>--enable-maintainer-mode</code><dd>The build rules that regenerate the Autoconf and Automake output files as
610well as the GCC master message catalog <samp><span class="file">gcc.pot</span></samp> are normally
611disabled.  This is because it can only be rebuilt if the complete source
612tree is present.  If you have changed the sources and want to rebuild the
613catalog, configuring with <samp><span class="option">--enable-maintainer-mode</span></samp> will enable
614this.  Note that you need a recent version of the <code>gettext</code> tools
615to do so.
616
617     <br><dt><code>--disable-bootstrap</code><dd>For a native build, the default configuration is to perform
618a 3-stage bootstrap of the compiler when &lsquo;<samp><span class="samp">make</span></samp>&rsquo; is invoked,
619testing that GCC can compile itself correctly.  If you want to disable
620this process, you can configure with <samp><span class="option">--disable-bootstrap</span></samp>.
621
622     <br><dt><code>--enable-bootstrap</code><dd>In special cases, you may want to perform a 3-stage build
623even if the target and host triplets are different. 
624This is possible when the host can run code compiled for
625the target (e.g. host is i686-linux, target is i486-linux). 
626Starting from GCC 4.2, to do this you have to configure explicitly
627with <samp><span class="option">--enable-bootstrap</span></samp>.
628
629     <br><dt><code>--enable-generated-files-in-srcdir</code><dd>Neither the .c and .h files that are generated from Bison and flex nor the
630info manuals and man pages that are built from the .texi files are present
631in the SVN development tree.  When building GCC from that development tree,
632or from one of our snapshots, those generated files are placed in your
633build directory, which allows for the source to be in a readonly
634directory.
635
636     <p>If you configure with <samp><span class="option">--enable-generated-files-in-srcdir</span></samp> then those
637generated files will go into the source directory.  This is mainly intended
638for generating release or prerelease tarballs of the GCC sources, since it
639is not a requirement that the users of source releases to have flex, Bison,
640or makeinfo.
641
642     <br><dt><code>--enable-version-specific-runtime-libs</code><dd>Specify
643that runtime libraries should be installed in the compiler specific
644subdirectory (<samp><var>libdir</var><span class="file">/gcc</span></samp>) rather than the usual places.  In
645addition, &lsquo;<samp><span class="samp">libstdc++</span></samp>&rsquo;'s include files will be installed into
646<samp><var>libdir</var></samp> unless you overruled it by using
647<samp><span class="option">--with-gxx-include-dir=</span><var>dirname</var></samp>.  Using this option is
648particularly useful if you intend to use several versions of GCC in
649parallel.  This is currently supported by &lsquo;<samp><span class="samp">libgfortran</span></samp>&rsquo;,
650&lsquo;<samp><span class="samp">libjava</span></samp>&rsquo;, &lsquo;<samp><span class="samp">libmudflap</span></samp>&rsquo;, &lsquo;<samp><span class="samp">libstdc++</span></samp>&rsquo;, and &lsquo;<samp><span class="samp">libobjc</span></samp>&rsquo;.
651
652     <br><dt><code>--enable-languages=</code><var>lang1</var><code>,</code><var>lang2</var><code>,...</code><dd>Specify that only a particular subset of compilers and
653their runtime libraries should be built.  For a list of valid values for
654<var>langN</var> you can issue the following command in the
655<samp><span class="file">gcc</span></samp> directory of your GCC source tree:<br>
656     <pre class="smallexample">          grep language= */config-lang.in
657</pre>
658     <p>Currently, you can use any of the following:
659<code>all</code>, <code>ada</code>, <code>c</code>, <code>c++</code>, <code>fortran</code>, <code>java</code>,
660<code>objc</code>, <code>obj-c++</code>. 
661Building the Ada compiler has special requirements, see below. 
662If you do not pass this flag, or specify the option <code>all</code>, then all
663default languages available in the <samp><span class="file">gcc</span></samp> sub-tree will be configured. 
664Ada and Objective-C++ are not default languages; the rest are. 
665Re-defining <code>LANGUAGES</code> when calling &lsquo;<samp><span class="samp">make</span></samp>&rsquo; <strong>does not</strong>
666work anymore, as those language sub-directories might not have been
667configured!
668
669     <br><dt><code>--enable-stage1-languages=</code><var>lang1</var><code>,</code><var>lang2</var><code>,...</code><dd>Specify that a particular subset of compilers and their runtime
670libraries should be built with the system C compiler during stage 1 of
671the bootstrap process, rather than only in later stages with the
672bootstrapped C compiler.  The list of valid values is the same as for
673<samp><span class="option">--enable-languages</span></samp>, and the option <code>all</code> will select all
674of the languages enabled by <samp><span class="option">--enable-languages</span></samp>.  This option is
675primarily useful for GCC development; for instance, when a development
676version of the compiler cannot bootstrap due to compiler bugs, or when
677one is debugging front ends other than the C front end.  When this
678option is used, one can then build the target libraries for the
679specified languages with the stage-1 compiler by using <samp><span class="command">make
680stage1-bubble all-target</span></samp>, or run the testsuite on the stage-1 compiler
681for the specified languages using <samp><span class="command">make stage1-start check-gcc</span></samp>.
682
683     <br><dt><code>--disable-libada</code><dd>Specify that the run-time libraries and tools used by GNAT should not
684be built.  This can be useful for debugging, or for compatibility with
685previous Ada build procedures, when it was required to explicitly
686do a &lsquo;<samp><span class="samp">make -C gcc gnatlib_and_tools</span></samp>&rsquo;.
687
688     <br><dt><code>--disable-libssp</code><dd>Specify that the run-time libraries for stack smashing protection
689should not be built.
690
691     <br><dt><code>--disable-libgomp</code><dd>Specify that the run-time libraries used by GOMP should not be built.
692
693     <br><dt><code>--with-dwarf2</code><dd>Specify that the compiler should
694use DWARF 2 debugging information as the default.
695
696     <br><dt><code>--enable-targets=all</code><dt><code>--enable-targets=</code><var>target_list</var><dd>Some GCC targets, e.g. powerpc64-linux, build bi-arch compilers. 
697These are compilers that are able to generate either 64-bit or 32-bit
698code.  Typically, the corresponding 32-bit target, e.g. 
699powerpc-linux for powerpc64-linux, only generates 32-bit code.  This
700option enables the 32-bit target to be a bi-arch compiler, which is
701useful when you want a bi-arch compiler that defaults to 32-bit, and
702you are building a bi-arch or multi-arch binutils in a combined tree. 
703On mips-linux, this will build a tri-arch compiler (ABI o32/n32/64),
704defaulted to o32. 
705Currently, this option only affects sparc-linux, powerpc-linux, x86-linux
706and mips-linux.
707
708     <br><dt><code>--enable-secureplt</code><dd>This option enables <samp><span class="option">-msecure-plt</span></samp> by default for powerpc-linux. 
709See &ldquo;RS/6000 and PowerPC Options&rdquo; in the main manual
710
711     <br><dt><code>--enable-cld</code><dd>This option enables <samp><span class="option">-mcld</span></samp> by default for 32-bit x86 targets. 
712See &ldquo;i386 and x86-64 Options&rdquo; in the main manual
713
714     <br><dt><code>--enable-win32-registry</code><dt><code>--enable-win32-registry=</code><var>key</var><dt><code>--disable-win32-registry</code><dd>The <samp><span class="option">--enable-win32-registry</span></samp> option enables Microsoft Windows-hosted GCC
715to look up installations paths in the registry using the following key:
716
717     <pre class="smallexample">          <code>HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\</code><var>key</var>
718</pre>
719     <p><var>key</var> defaults to GCC version number, and can be overridden by the
720<samp><span class="option">--enable-win32-registry=</span><var>key</var></samp> option.  Vendors and distributors
721who use custom installers are encouraged to provide a different key,
722perhaps one comprised of vendor name and GCC version number, to
723avoid conflict with existing installations.  This feature is enabled
724by default, and can be disabled by <samp><span class="option">--disable-win32-registry</span></samp>
725option.  This option has no effect on the other hosts.
726
727     <br><dt><code>--nfp</code><dd>Specify that the machine does not have a floating point unit.  This
728option only applies to &lsquo;<samp><span class="samp">m68k-sun-sunos</span><var>n</var></samp>&rsquo;.  On any other
729system, <samp><span class="option">--nfp</span></samp> has no effect.
730
731     <br><dt><code>--enable-werror</code><dt><code>--disable-werror</code><dt><code>--enable-werror=yes</code><dt><code>--enable-werror=no</code><dd>When you specify this option, it controls whether certain files in the
732compiler are built with <samp><span class="option">-Werror</span></samp> in bootstrap stage2 and later. 
733If you don't specify it, <samp><span class="option">-Werror</span></samp> is turned on for the main
734development trunk.  However it defaults to off for release branches and
735final releases.  The specific files which get <samp><span class="option">-Werror</span></samp> are
736controlled by the Makefiles.
737
738     <br><dt><code>--enable-checking</code><dt><code>--enable-checking=</code><var>list</var><dd>When you specify this option, the compiler is built to perform internal
739consistency checks of the requested complexity.  This does not change the
740generated code, but adds error checking within the compiler.  This will
741slow down the compiler and may only work properly if you are building
742the compiler with GCC.  This is &lsquo;<samp><span class="samp">yes</span></samp>&rsquo; by default when building
743from SVN or snapshots, but &lsquo;<samp><span class="samp">release</span></samp>&rsquo; for releases.  The default
744for building the stage1 compiler is &lsquo;<samp><span class="samp">yes</span></samp>&rsquo;.  More control
745over the checks may be had by specifying <var>list</var>.  The categories of
746checks available are &lsquo;<samp><span class="samp">yes</span></samp>&rsquo; (most common checks
747&lsquo;<samp><span class="samp">assert,misc,tree,gc,rtlflag,runtime</span></samp>&rsquo;), &lsquo;<samp><span class="samp">no</span></samp>&rsquo; (no checks at
748all), &lsquo;<samp><span class="samp">all</span></samp>&rsquo; (all but &lsquo;<samp><span class="samp">valgrind</span></samp>&rsquo;), &lsquo;<samp><span class="samp">release</span></samp>&rsquo; (cheapest
749checks &lsquo;<samp><span class="samp">assert,runtime</span></samp>&rsquo;) or &lsquo;<samp><span class="samp">none</span></samp>&rsquo; (same as &lsquo;<samp><span class="samp">no</span></samp>&rsquo;). 
750Individual checks can be enabled with these flags &lsquo;<samp><span class="samp">assert</span></samp>&rsquo;,
751&lsquo;<samp><span class="samp">df</span></samp>&rsquo;, &lsquo;<samp><span class="samp">fold</span></samp>&rsquo;, &lsquo;<samp><span class="samp">gc</span></samp>&rsquo;, &lsquo;<samp><span class="samp">gcac</span></samp>&rsquo; &lsquo;<samp><span class="samp">misc</span></samp>&rsquo;, &lsquo;<samp><span class="samp">rtl</span></samp>&rsquo;,
752&lsquo;<samp><span class="samp">rtlflag</span></samp>&rsquo;, &lsquo;<samp><span class="samp">runtime</span></samp>&rsquo;, &lsquo;<samp><span class="samp">tree</span></samp>&rsquo;, and &lsquo;<samp><span class="samp">valgrind</span></samp>&rsquo;.
753
754     <p>The &lsquo;<samp><span class="samp">valgrind</span></samp>&rsquo; check requires the external <samp><span class="command">valgrind</span></samp>
755simulator, available from <a href="http://valgrind.org/">http://valgrind.org/</a>.  The
756&lsquo;<samp><span class="samp">df</span></samp>&rsquo;, &lsquo;<samp><span class="samp">rtl</span></samp>&rsquo;, &lsquo;<samp><span class="samp">gcac</span></samp>&rsquo; and &lsquo;<samp><span class="samp">valgrind</span></samp>&rsquo; checks are very expensive. 
757To disable all checking, &lsquo;<samp><span class="samp">--disable-checking</span></samp>&rsquo; or
758&lsquo;<samp><span class="samp">--enable-checking=none</span></samp>&rsquo; must be explicitly requested.  Disabling
759assertions will make the compiler and runtime slightly faster but
760increase the risk of undetected internal errors causing wrong code to be
761generated.
762
763     <br><dt><code>--disable-stage1-checking</code><dt><code>--enable-stage1-checking</code><dt><code>--enable-stage1-checking=</code><var>list</var><dd>If no <samp><span class="option">--enable-checking</span></samp> option is specified the stage1
764compiler will be built with &lsquo;<samp><span class="samp">yes</span></samp>&rsquo; checking enabled, otherwise
765the stage1 checking flags are the same as specified by
766<samp><span class="option">--enable-checking</span></samp>.  To build the stage1 compiler with
767different checking options use <samp><span class="option">--enable-stage1-checking</span></samp>. 
768The list of checking options is the same as for <samp><span class="option">--enable-checking</span></samp>. 
769If your system is too slow or too small to bootstrap a released compiler
770with checking for stage1 enabled, you can use &lsquo;<samp><span class="samp">--disable-stage1-checking</span></samp>&rsquo;
771to disable checking for the stage1 compiler.
772
773     <br><dt><code>--enable-coverage</code><dt><code>--enable-coverage=</code><var>level</var><dd>With this option, the compiler is built to collect self coverage
774information, every time it is run.  This is for internal development
775purposes, and only works when the compiler is being built with gcc.  The
776<var>level</var> argument controls whether the compiler is built optimized or
777not, values are &lsquo;<samp><span class="samp">opt</span></samp>&rsquo; and &lsquo;<samp><span class="samp">noopt</span></samp>&rsquo;.  For coverage analysis you
778want to disable optimization, for performance analysis you want to
779enable optimization.  When coverage is enabled, the default level is
780without optimization.
781
782     <br><dt><code>--enable-gather-detailed-mem-stats</code><dd>When this option is specified more detailed information on memory
783allocation is gathered.  This information is printed when using
784<samp><span class="option">-fmem-report</span></samp>.
785
786     <br><dt><code>--with-gc</code><dt><code>--with-gc=</code><var>choice</var><dd>With this option you can specify the garbage collector implementation
787used during the compilation process.  <var>choice</var> can be one of
788&lsquo;<samp><span class="samp">page</span></samp>&rsquo; and &lsquo;<samp><span class="samp">zone</span></samp>&rsquo;, where &lsquo;<samp><span class="samp">page</span></samp>&rsquo; is the default.
789
790     <br><dt><code>--enable-nls</code><dt><code>--disable-nls</code><dd>The <samp><span class="option">--enable-nls</span></samp> option enables Native Language Support (NLS),
791which lets GCC output diagnostics in languages other than American
792English.  Native Language Support is enabled by default if not doing a
793canadian cross build.  The <samp><span class="option">--disable-nls</span></samp> option disables NLS.
794
795     <br><dt><code>--with-included-gettext</code><dd>If NLS is enabled, the <samp><span class="option">--with-included-gettext</span></samp> option causes the build
796procedure to prefer its copy of GNU <samp><span class="command">gettext</span></samp>.
797
798     <br><dt><code>--with-catgets</code><dd>If NLS is enabled, and if the host lacks <code>gettext</code> but has the
799inferior <code>catgets</code> interface, the GCC build procedure normally
800ignores <code>catgets</code> and instead uses GCC's copy of the GNU
801<code>gettext</code> library.  The <samp><span class="option">--with-catgets</span></samp> option causes the
802build procedure to use the host's <code>catgets</code> in this situation.
803
804     <br><dt><code>--with-libiconv-prefix=</code><var>dir</var><dd>Search for libiconv header files in <samp><var>dir</var><span class="file">/include</span></samp> and
805libiconv library files in <samp><var>dir</var><span class="file">/lib</span></samp>.
806
807     <br><dt><code>--enable-obsolete</code><dd>Enable configuration for an obsoleted system.  If you attempt to
808configure GCC for a system (build, host, or target) which has been
809obsoleted, and you do not specify this flag, configure will halt with an
810error message.
811
812     <p>All support for systems which have been obsoleted in one release of GCC
813is removed entirely in the next major release, unless someone steps
814forward to maintain the port.
815
816     <br><dt><code>--enable-decimal-float</code><dt><code>--enable-decimal-float=yes</code><dt><code>--enable-decimal-float=no</code><dt><code>--enable-decimal-float=bid</code><dt><code>--enable-decimal-float=dpd</code><dt><code>--disable-decimal-float</code><dd>Enable (or disable) support for the C decimal floating point extension
817that is in the IEEE 754-2008 standard.  This is enabled by default only
818on PowerPC, i386, and x86_64 GNU/Linux systems.  Other systems may also
819support it, but require the user to specifically enable it.  You can
820optionally control which decimal floating point format is used (either
821&lsquo;<samp><span class="samp">bid</span></samp>&rsquo; or &lsquo;<samp><span class="samp">dpd</span></samp>&rsquo;).  The &lsquo;<samp><span class="samp">bid</span></samp>&rsquo; (binary integer decimal)
822format is default on i386 and x86_64 systems, and the &lsquo;<samp><span class="samp">dpd</span></samp>&rsquo;
823(densely packed decimal) format is default on PowerPC systems.
824
825     <br><dt><code>--enable-fixed-point</code><dt><code>--disable-fixed-point</code><dd>Enable (or disable) support for C fixed-point arithmetic. 
826This option is enabled by default for some targets (such as MIPS) which
827have hardware-support for fixed-point operations.  On other targets, you
828may enable this option manually.
829
830     <br><dt><code>--with-long-double-128</code><dd>Specify if <code>long double</code> type should be 128-bit by default on selected
831GNU/Linux architectures.  If using <code>--without-long-double-128</code>,
832<code>long double</code> will be by default 64-bit, the same as <code>double</code> type. 
833When neither of these configure options are used, the default will be
834128-bit <code>long double</code> when built against GNU C Library 2.4 and later,
83564-bit <code>long double</code> otherwise.
836
837     <br><dt><code>--with-gmp=</code><var>pathname</var><dt><code>--with-gmp-include=</code><var>pathname</var><dt><code>--with-gmp-lib=</code><var>pathname</var><dt><code>--with-mpfr=</code><var>pathname</var><dt><code>--with-mpfr-include=</code><var>pathname</var><dt><code>--with-mpfr-lib=</code><var>pathname</var><dt><code>--with-mpc=</code><var>pathname</var><dt><code>--with-mpc-include=</code><var>pathname</var><dt><code>--with-mpc-lib=</code><var>pathname</var><dd>If you do not have GMP (the GNU Multiple Precision library), the MPFR
838library and/or the MPC library installed in a standard location and
839you want to build GCC, you can explicitly specify the directory where
840they are installed (&lsquo;<samp><span class="samp">--with-gmp=</span><var>gmpinstalldir</var></samp>&rsquo;,
841&lsquo;<samp><span class="samp">--with-mpfr=</span><var>mpfrinstalldir</var></samp>&rsquo;,
842&lsquo;<samp><span class="samp">--with-mpc=</span><var>mpcinstalldir</var></samp>&rsquo;).  The
843<samp><span class="option">--with-gmp=</span><var>gmpinstalldir</var></samp> option is shorthand for
844<samp><span class="option">--with-gmp-lib=</span><var>gmpinstalldir</var><span class="option">/lib</span></samp> and
845<samp><span class="option">--with-gmp-include=</span><var>gmpinstalldir</var><span class="option">/include</span></samp>.  Likewise the
846<samp><span class="option">--with-mpfr=</span><var>mpfrinstalldir</var></samp> option is shorthand for
847<samp><span class="option">--with-mpfr-lib=</span><var>mpfrinstalldir</var><span class="option">/lib</span></samp> and
848<samp><span class="option">--with-mpfr-include=</span><var>mpfrinstalldir</var><span class="option">/include</span></samp>, also the
849<samp><span class="option">--with-mpc=</span><var>mpcinstalldir</var></samp> option is shorthand for
850<samp><span class="option">--with-mpc-lib=</span><var>mpcinstalldir</var><span class="option">/lib</span></samp> and
851<samp><span class="option">--with-mpc-include=</span><var>mpcinstalldir</var><span class="option">/include</span></samp>.  If these
852shorthand assumptions are not correct, you can use the explicit
853include and lib options directly.
854
855     <br><dt><code>--with-ppl=</code><var>pathname</var><dt><code>--with-ppl-include=</code><var>pathname</var><dt><code>--with-ppl-lib=</code><var>pathname</var><dt><code>--with-cloog=</code><var>pathname</var><dt><code>--with-cloog-include=</code><var>pathname</var><dt><code>--with-cloog-lib=</code><var>pathname</var><dd>If you do not have PPL (the Parma Polyhedra Library) and the CLooG
856libraries installed in a standard location and you want to build GCC,
857you can explicitly specify the directory where they are installed
858(&lsquo;<samp><span class="samp">--with-ppl=</span><var>pplinstalldir</var></samp>&rsquo;,
859&lsquo;<samp><span class="samp">--with-cloog=</span><var>clooginstalldir</var></samp>&rsquo;). The
860<samp><span class="option">--with-ppl=</span><var>pplinstalldir</var></samp> option is shorthand for
861<samp><span class="option">--with-ppl-lib=</span><var>pplinstalldir</var><span class="option">/lib</span></samp> and
862<samp><span class="option">--with-ppl-include=</span><var>pplinstalldir</var><span class="option">/include</span></samp>.  Likewise the
863<samp><span class="option">--with-cloog=</span><var>clooginstalldir</var></samp> option is shorthand for
864<samp><span class="option">--with-cloog-lib=</span><var>clooginstalldir</var><span class="option">/lib</span></samp> and
865<samp><span class="option">--with-cloog-include=</span><var>clooginstalldir</var><span class="option">/include</span></samp>.  If these
866shorthand assumptions are not correct, you can use the explicit
867include and lib options directly.
868
869     <br><dt><code>--with-host-libstdcxx=</code><var>linker-args</var><dd>If you are linking with a static copy of PPL, you can use this option
870to specify how the linker should find the standard C++ library used
871internally by PPL.  Typical values of <var>linker-args</var> might be
872&lsquo;<samp><span class="samp">-lstdc++</span></samp>&rsquo; or &lsquo;<samp><span class="samp">-Wl,-Bstatic,-lstdc++,-Bdynamic -lm</span></samp>&rsquo;.  If you are
873linking with a shared copy of PPL, you probably do not need this
874option; shared library dependencies will cause the linker to search
875for the standard C++ library automatically.
876
877     <br><dt><code>--with-stage1-ldflags=</code><var>flags</var><dd>This option may be used to set linker flags to be used when linking
878stage 1 of GCC.  These are also used when linking GCC if configured with
879<samp><span class="option">--disable-bootstrap</span></samp>.  By default no special flags are used.
880
881     <br><dt><code>--with-stage1-libs=</code><var>libs</var><dd>This option may be used to set libraries to be used when linking stage 1
882of GCC.  These are also used when linking GCC if configured with
883<samp><span class="option">--disable-bootstrap</span></samp>.  The default is the argument to
884<samp><span class="option">--with-host-libstdcxx</span></samp>, if specified.
885
886     <br><dt><code>--with-boot-ldflags=</code><var>flags</var><dd>This option may be used to set linker flags to be used when linking
887stage 2 and later when bootstrapping GCC.  By default no special flags
888are used.
889
890     <br><dt><code>--with-boot-libs=</code><var>libs</var><dd>This option may be used to set libraries to be used when linking stage 2
891and later when bootstrapping GCC.  The default is the argument to
892<samp><span class="option">--with-host-libstdcxx</span></samp>, if specified.
893
894     <br><dt><code>--with-debug-prefix-map=</code><var>map</var><dd>Convert source directory names using <samp><span class="option">-fdebug-prefix-map</span></samp> when
895building runtime libraries.  &lsquo;<samp><var>map</var></samp>&rsquo; is a space-separated
896list of maps of the form &lsquo;<samp><var>old</var><span class="samp">=</span><var>new</var></samp>&rsquo;.
897
898     <br><dt><code>--enable-linker-build-id</code><dd>Tells GCC to pass <samp><span class="option">--build-id</span></samp> option to the linker for all final
899links (links performed without the <samp><span class="option">-r</span></samp> or <samp><span class="option">--relocatable</span></samp>
900option), if the linker supports it.  If you specify
901<samp><span class="option">--enable-linker-build-id</span></samp>, but your linker does not
902support <samp><span class="option">--build-id</span></samp> option, a warning is issued and the
903<samp><span class="option">--enable-linker-build-id</span></samp> option is ignored.  The default is off.
904
905     <br><dt><code>--enable-gnu-unique-object</code><dt><code>--disable-gnu-unique-object</code><dd>Tells GCC to use the gnu_unique_object relocation for C++ template
906static data members and inline function local statics.  Enabled by
907default for a native toolchain with an assembler that accepts it and
908GLIBC 2.11 or above, otherwise disabled.
909
910     <br><dt><code>--enable-lto</code><dd>Enable support for link-time optimization (LTO).  This is enabled by
911default if a working libelf implementation is found (see
912<samp><span class="option">--with-libelf</span></samp>).
913
914     <br><dt><code>--with-libelf=</code><var>pathname</var><dt><code>--with-libelf-include=</code><var>pathname</var><dt><code>--with-libelf-lib=</code><var>pathname</var><dd>If you do not have libelf installed in a standard location and you
915want to enable support for link-time optimization (LTO), you can
916explicitly specify the directory where libelf is installed
917(&lsquo;<samp><span class="samp">--with-libelf=</span><var>libelfinstalldir</var></samp>&rsquo;).  The
918<samp><span class="option">--with-libelf=</span><var>libelfinstalldir</var></samp> option is shorthand for
919<samp><span class="option">--with-libelf-include=</span><var>libelfinstalldir</var><span class="option">/include</span></samp>
920<samp><span class="option">--with-libelf-lib=</span><var>libelfinstalldir</var><span class="option">/lib</span></samp>.
921
922     <br><dt><code>--enable-gold</code><dd>Enable support for using <samp><span class="command">gold</span></samp> as the linker.  If gold support is
923enabled together with <samp><span class="option">--enable-lto</span></samp>, an additional directory
924<samp><span class="file">lto-plugin</span></samp> will be built.  The code in this directory is a
925plugin for gold that allows the link-time optimizer to extract object
926files with LTO information out of library archives.  See
927<samp><span class="option">-flto</span></samp> and <samp><span class="option">-fwhopr</span></samp> for details. 
928</dl>
929
930<h4 class="subheading"><a name="TOC3"></a>Cross-Compiler-Specific Options</h4>
931
932<p>The following options only apply to building cross compilers.
933
934     <dl>
935<dt><code>--with-sysroot</code><dt><code>--with-sysroot=</code><var>dir</var><dd>Tells GCC to consider <var>dir</var> as the root of a tree that contains a
936(subset of) the root filesystem of the target operating system. 
937Target system headers, libraries and run-time object files will be
938searched in there.  More specifically, this acts as if
939<samp><span class="option">--sysroot=</span><var>dir</var></samp> was added to the default options of the built
940compiler.  The specified directory is not copied into the
941install tree, unlike the options <samp><span class="option">--with-headers</span></samp> and
942<samp><span class="option">--with-libs</span></samp> that this option obsoletes.  The default value,
943in case <samp><span class="option">--with-sysroot</span></samp> is not given an argument, is
944<samp><span class="option">${gcc_tooldir}/sys-root</span></samp>.  If the specified directory is a
945subdirectory of <samp><span class="option">${exec_prefix}</span></samp>, then it will be found relative to
946the GCC binaries if the installation tree is moved.
947
948     <p>This option affects the system root for the compiler used to build
949target libraries (which runs on the build system) and the compiler newly
950installed with <code>make install</code>; it does not affect the compiler which is
951used to build GCC itself.
952
953     <br><dt><code>--with-build-sysroot</code><dt><code>--with-build-sysroot=</code><var>dir</var><dd>Tells GCC to consider <var>dir</var> as the system root (see
954<samp><span class="option">--with-sysroot</span></samp>) while building target libraries, instead of
955the directory specified with <samp><span class="option">--with-sysroot</span></samp>.  This option is
956only useful when you are already using <samp><span class="option">--with-sysroot</span></samp>.  You
957can use <samp><span class="option">--with-build-sysroot</span></samp> when you are configuring with
958<samp><span class="option">--prefix</span></samp> set to a directory that is different from the one in
959which you are installing GCC and your target libraries.
960
961     <p>This option affects the system root for the compiler used to build
962target libraries (which runs on the build system); it does not affect
963the compiler which is used to build GCC itself.
964
965     <br><dt><code>--with-headers</code><dt><code>--with-headers=</code><var>dir</var><dd>Deprecated in favor of <samp><span class="option">--with-sysroot</span></samp>. 
966Specifies that target headers are available when building a cross compiler. 
967The <var>dir</var> argument specifies a directory which has the target include
968files.  These include files will be copied into the <samp><span class="file">gcc</span></samp> install
969directory.  <em>This option with the </em><var>dir</var><em> argument is required</em> when
970building a cross compiler, if <samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/sys-include</span></samp>
971doesn't pre-exist.  If <samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/sys-include</span></samp> does
972pre-exist, the <var>dir</var> argument may be omitted.  <samp><span class="command">fixincludes</span></samp>
973will be run on these files to make them compatible with GCC.
974
975     <br><dt><code>--without-headers</code><dd>Tells GCC not use any target headers from a libc when building a cross
976compiler.  When crossing to GNU/Linux, you need the headers so GCC
977can build the exception handling for libgcc.
978
979     <br><dt><code>--with-libs</code><dt><code>--with-libs="</code><var>dir1</var> <var>dir2</var><code> ... </code><var>dirN</var><code>"</code><dd>Deprecated in favor of <samp><span class="option">--with-sysroot</span></samp>. 
980Specifies a list of directories which contain the target runtime
981libraries.  These libraries will be copied into the <samp><span class="file">gcc</span></samp> install
982directory.  If the directory list is omitted, this option has no
983effect.
984
985     <br><dt><code>--with-newlib</code><dd>Specifies that &lsquo;<samp><span class="samp">newlib</span></samp>&rsquo; is
986being used as the target C library.  This causes <code>__eprintf</code> to be
987omitted from <samp><span class="file">libgcc.a</span></samp> on the assumption that it will be provided by
988&lsquo;<samp><span class="samp">newlib</span></samp>&rsquo;.
989
990     <br><dt><code>--with-build-time-tools=</code><var>dir</var><dd>Specifies where to find the set of target tools (assembler, linker, etc.) 
991that will be used while building GCC itself.  This option can be useful
992if the directory layouts are different between the system you are building
993GCC on, and the system where you will deploy it.
994
995     <p>For example, on an &lsquo;<samp><span class="samp">ia64-hp-hpux</span></samp>&rsquo; system, you may have the GNU
996assembler and linker in <samp><span class="file">/usr/bin</span></samp>, and the native tools in a
997different path, and build a toolchain that expects to find the
998native tools in <samp><span class="file">/usr/bin</span></samp>.
999
1000     <p>When you use this option, you should ensure that <var>dir</var> includes
1001<samp><span class="command">ar</span></samp>, <samp><span class="command">as</span></samp>, <samp><span class="command">ld</span></samp>, <samp><span class="command">nm</span></samp>,
1002<samp><span class="command">ranlib</span></samp> and <samp><span class="command">strip</span></samp> if necessary, and possibly
1003<samp><span class="command">objdump</span></samp>.  Otherwise, GCC may use an inconsistent set of
1004tools. 
1005</dl>
1006
1007<h4 class="subheading"><a name="TOC4"></a>Java-Specific Options</h4>
1008
1009<p>The following option applies to the build of the Java front end.
1010
1011     <dl>
1012<dt><code>--disable-libgcj</code><dd>Specify that the run-time libraries
1013used by GCJ should not be built.  This is useful in case you intend
1014to use GCJ with some other run-time, or you're going to install it
1015separately, or it just happens not to build on your particular
1016machine.  In general, if the Java front end is enabled, the GCJ
1017libraries will be enabled too, unless they're known to not work on
1018the target platform.  If GCJ is enabled but &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo; isn't built, you
1019may need to port it; in this case, before modifying the top-level
1020<samp><span class="file">configure.in</span></samp> so that &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo; is enabled by default on this platform,
1021you may use <samp><span class="option">--enable-libgcj</span></samp> to override the default.
1022
1023   </dl>
1024
1025   <p>The following options apply to building &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo;.
1026
1027<h5 class="subsubheading"><a name="TOC5"></a>General Options</h5>
1028
1029     <dl>
1030<dt><code>--enable-java-maintainer-mode</code><dd>By default the &lsquo;<samp><span class="samp">libjava</span></samp>&rsquo; build will not attempt to compile the
1031<samp><span class="file">.java</span></samp> source files to <samp><span class="file">.class</span></samp>.  Instead, it will use the
1032<samp><span class="file">.class</span></samp> files from the source tree.  If you use this option you
1033must have executables named <samp><span class="command">ecj1</span></samp> and <samp><span class="command">gjavah</span></samp> in your path
1034for use by the build.  You must use this option if you intend to
1035modify any <samp><span class="file">.java</span></samp> files in <samp><span class="file">libjava</span></samp>.
1036
1037     <br><dt><code>--with-java-home=</code><var>dirname</var><dd>This &lsquo;<samp><span class="samp">libjava</span></samp>&rsquo; option overrides the default value of the
1038&lsquo;<samp><span class="samp">java.home</span></samp>&rsquo; system property.  It is also used to set
1039&lsquo;<samp><span class="samp">sun.boot.class.path</span></samp>&rsquo; to <samp><var>dirname</var><span class="file">/lib/rt.jar</span></samp>.  By
1040default &lsquo;<samp><span class="samp">java.home</span></samp>&rsquo; is set to <samp><var>prefix</var></samp> and
1041&lsquo;<samp><span class="samp">sun.boot.class.path</span></samp>&rsquo; to
1042<samp><var>datadir</var><span class="file">/java/libgcj-</span><var>version</var><span class="file">.jar</span></samp>.
1043
1044     <br><dt><code>--with-ecj-jar=</code><var>filename</var><dd>This option can be used to specify the location of an external jar
1045file containing the Eclipse Java compiler.  A specially modified
1046version of this compiler is used by <samp><span class="command">gcj</span></samp> to parse
1047<samp><span class="file">.java</span></samp> source files.  If this option is given, the
1048&lsquo;<samp><span class="samp">libjava</span></samp>&rsquo; build will create and install an <samp><span class="file">ecj1</span></samp> executable
1049which uses this jar file at runtime.
1050
1051     <p>If this option is not given, but an <samp><span class="file">ecj.jar</span></samp> file is found in
1052the topmost source tree at configure time, then the &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo;
1053build will create and install <samp><span class="file">ecj1</span></samp>, and will also install the
1054discovered <samp><span class="file">ecj.jar</span></samp> into a suitable place in the install tree.
1055
1056     <p>If <samp><span class="file">ecj1</span></samp> is not installed, then the user will have to supply one
1057on his path in order for <samp><span class="command">gcj</span></samp> to properly parse <samp><span class="file">.java</span></samp>
1058source files.  A suitable jar is available from
1059<a href="ftp://sourceware.org/pub/java/">ftp://sourceware.org/pub/java/</a>.
1060
1061     <br><dt><code>--disable-getenv-properties</code><dd>Don't set system properties from <samp><span class="env">GCJ_PROPERTIES</span></samp>.
1062
1063     <br><dt><code>--enable-hash-synchronization</code><dd>Use a global hash table for monitor locks.  Ordinarily,
1064&lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo;'s &lsquo;<samp><span class="samp">configure</span></samp>&rsquo; script automatically makes
1065the correct choice for this option for your platform.  Only use
1066this if you know you need the library to be configured differently.
1067
1068     <br><dt><code>--enable-interpreter</code><dd>Enable the Java interpreter.  The interpreter is automatically
1069enabled by default on all platforms that support it.  This option
1070is really only useful if you want to disable the interpreter
1071(using <samp><span class="option">--disable-interpreter</span></samp>).
1072
1073     <br><dt><code>--disable-java-net</code><dd>Disable java.net.  This disables the native part of java.net only,
1074using non-functional stubs for native method implementations.
1075
1076     <br><dt><code>--disable-jvmpi</code><dd>Disable JVMPI support.
1077
1078     <br><dt><code>--disable-libgcj-bc</code><dd>Disable BC ABI compilation of certain parts of libgcj.  By default,
1079some portions of libgcj are compiled with <samp><span class="option">-findirect-dispatch</span></samp>
1080and <samp><span class="option">-fno-indirect-classes</span></samp>, allowing them to be overridden at
1081run-time.
1082
1083     <p>If <samp><span class="option">--disable-libgcj-bc</span></samp> is specified, libgcj is built without
1084these options.  This allows the compile-time linker to resolve
1085dependencies when statically linking to libgcj.  However it makes it
1086impossible to override the affected portions of libgcj at run-time.
1087
1088     <br><dt><code>--enable-reduced-reflection</code><dd>Build most of libgcj with <samp><span class="option">-freduced-reflection</span></samp>.  This reduces
1089the size of libgcj at the expense of not being able to do accurate
1090reflection on the classes it contains.  This option is safe if you
1091know that code using libgcj will never use reflection on the standard
1092runtime classes in libgcj (including using serialization, RMI or CORBA).
1093
1094     <br><dt><code>--with-ecos</code><dd>Enable runtime eCos target support.
1095
1096     <br><dt><code>--without-libffi</code><dd>Don't use &lsquo;<samp><span class="samp">libffi</span></samp>&rsquo;.  This will disable the interpreter and JNI
1097support as well, as these require &lsquo;<samp><span class="samp">libffi</span></samp>&rsquo; to work.
1098
1099     <br><dt><code>--enable-libgcj-debug</code><dd>Enable runtime debugging code.
1100
1101     <br><dt><code>--enable-libgcj-multifile</code><dd>If specified, causes all <samp><span class="file">.java</span></samp> source files to be
1102compiled into <samp><span class="file">.class</span></samp> files in one invocation of
1103&lsquo;<samp><span class="samp">gcj</span></samp>&rsquo;.  This can speed up build time, but is more
1104resource-intensive.  If this option is unspecified or
1105disabled, &lsquo;<samp><span class="samp">gcj</span></samp>&rsquo; is invoked once for each <samp><span class="file">.java</span></samp>
1106file to compile into a <samp><span class="file">.class</span></samp> file.
1107
1108     <br><dt><code>--with-libiconv-prefix=DIR</code><dd>Search for libiconv in <samp><span class="file">DIR/include</span></samp> and <samp><span class="file">DIR/lib</span></samp>.
1109
1110     <br><dt><code>--enable-sjlj-exceptions</code><dd>Force use of the <code>setjmp</code>/<code>longjmp</code>-based scheme for exceptions. 
1111&lsquo;<samp><span class="samp">configure</span></samp>&rsquo; ordinarily picks the correct value based on the platform. 
1112Only use this option if you are sure you need a different setting.
1113
1114     <br><dt><code>--with-system-zlib</code><dd>Use installed &lsquo;<samp><span class="samp">zlib</span></samp>&rsquo; rather than that included with GCC.
1115
1116     <br><dt><code>--with-win32-nlsapi=ansi, unicows or unicode</code><dd>Indicates how MinGW &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo; translates between UNICODE
1117characters and the Win32 API.
1118
1119     <br><dt><code>--enable-java-home</code><dd>If enabled, this creates a JPackage compatible SDK environment during install. 
1120Note that if &ndash;enable-java-home is used, &ndash;with-arch-directory=ARCH must also
1121be specified.
1122
1123     <br><dt><code>--with-arch-directory=ARCH</code><dd>Specifies the name to use for the <samp><span class="file">jre/lib/ARCH</span></samp> directory in the SDK
1124environment created when &ndash;enable-java-home is passed. Typical names for this
1125directory include i386, amd64, ia64, etc.
1126
1127     <br><dt><code>--with-os-directory=DIR</code><dd>Specifies the OS directory for the SDK include directory. This is set to auto
1128detect, and is typically 'linux'.
1129
1130     <br><dt><code>--with-origin-name=NAME</code><dd>Specifies the JPackage origin name. This defaults to the 'gcj' in
1131java-1.5.0-gcj.
1132
1133     <br><dt><code>--with-arch-suffix=SUFFIX</code><dd>Specifies the suffix for the sdk directory. Defaults to the empty string. 
1134Examples include '.x86_64' in 'java-1.5.0-gcj-1.5.0.0.x86_64'.
1135
1136     <br><dt><code>--with-jvm-root-dir=DIR</code><dd>Specifies where to install the SDK. Default is $(prefix)/lib/jvm.
1137
1138     <br><dt><code>--with-jvm-jar-dir=DIR</code><dd>Specifies where to install jars. Default is $(prefix)/lib/jvm-exports.
1139
1140     <br><dt><code>--with-python-dir=DIR</code><dd>Specifies where to install the Python modules used for aot-compile. DIR should
1141not include the prefix used in installation. For example, if the Python modules
1142are to be installed in /usr/lib/python2.5/site-packages, then
1143&ndash;with-python-dir=/lib/python2.5/site-packages should be passed. If this is
1144not specified, then the Python modules are installed in $(prefix)/share/python.
1145
1146     <br><dt><code>--enable-aot-compile-rpm</code><dd>Adds aot-compile-rpm to the list of installed scripts.
1147
1148     <br><dt><code>--enable-browser-plugin</code><dd>Build the gcjwebplugin web browser plugin.
1149
1150          <dl>
1151<dt><code>ansi</code><dd>Use the single-byte <code>char</code> and the Win32 A functions natively,
1152translating to and from UNICODE when using these functions.  If
1153unspecified, this is the default.
1154
1155          <br><dt><code>unicows</code><dd>Use the <code>WCHAR</code> and Win32 W functions natively.  Adds
1156<code>-lunicows</code> to <samp><span class="file">libgcj.spec</span></samp> to link with &lsquo;<samp><span class="samp">libunicows</span></samp>&rsquo;. 
1157<samp><span class="file">unicows.dll</span></samp> needs to be deployed on Microsoft Windows 9X machines
1158running built executables.  <samp><span class="file">libunicows.a</span></samp>, an open-source
1159import library around Microsoft's <code>unicows.dll</code>, is obtained from
1160<a href="http://libunicows.sourceforge.net/">http://libunicows.sourceforge.net/</a>, which also gives details
1161on getting <samp><span class="file">unicows.dll</span></samp> from Microsoft.
1162
1163          <br><dt><code>unicode</code><dd>Use the <code>WCHAR</code> and Win32 W functions natively.  Does <em>not</em>
1164add <code>-lunicows</code> to <samp><span class="file">libgcj.spec</span></samp>.  The built executables will
1165only run on Microsoft Windows NT and above. 
1166</dl>
1167     </dl>
1168
1169<h5 class="subsubheading"><a name="TOC6"></a>AWT-Specific Options</h5>
1170
1171     <dl>
1172<dt><code>--with-x</code><dd>Use the X Window System.
1173
1174     <br><dt><code>--enable-java-awt=PEER(S)</code><dd>Specifies the AWT peer library or libraries to build alongside
1175&lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo;.  If this option is unspecified or disabled, AWT
1176will be non-functional.  Current valid values are <samp><span class="option">gtk</span></samp> and
1177<samp><span class="option">xlib</span></samp>.  Multiple libraries should be separated by a
1178comma (i.e. <samp><span class="option">--enable-java-awt=gtk,xlib</span></samp>).
1179
1180     <br><dt><code>--enable-gtk-cairo</code><dd>Build the cairo Graphics2D implementation on GTK.
1181
1182     <br><dt><code>--enable-java-gc=TYPE</code><dd>Choose garbage collector.  Defaults to <samp><span class="option">boehm</span></samp> if unspecified.
1183
1184     <br><dt><code>--disable-gtktest</code><dd>Do not try to compile and run a test GTK+ program.
1185
1186     <br><dt><code>--disable-glibtest</code><dd>Do not try to compile and run a test GLIB program.
1187
1188     <br><dt><code>--with-libart-prefix=PFX</code><dd>Prefix where libart is installed (optional).
1189
1190     <br><dt><code>--with-libart-exec-prefix=PFX</code><dd>Exec prefix where libart is installed (optional).
1191
1192     <br><dt><code>--disable-libarttest</code><dd>Do not try to compile and run a test libart program.
1193
1194</dl>
1195
1196   <p><hr />
1197<p><a href="./index.html">Return to the GCC Installation page</a>
1198
1199<!-- ***Building**************************************************************** -->
1200<!-- ***Testing***************************************************************** -->
1201<!-- ***Final install*********************************************************** -->
1202<!-- ***Binaries**************************************************************** -->
1203<!-- ***Specific**************************************************************** -->
1204<!-- ***Old documentation****************************************************** -->
1205<!-- ***GFDL******************************************************************** -->
1206<!-- *************************************************************************** -->
1207<!-- Part 6 The End of the Document -->
1208</body></html>
1209
1210