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     42  1.7  mrg <h1 class="settitle">Installing GCC: Configuration</h1>
     43  1.7  mrg <a name="index-Configuration-1"></a><a name="index-Installing-GCC_003a-Configuration-2"></a>
     44  1.7  mrg Like most GNU software, GCC must be configured before it can be built. 
     45  1.7  mrg This document describes the recommended configuration procedure
     46  1.7  mrg for both native and cross targets.
     47  1.6  mrg 
     48  1.7  mrg    <p>We use <var>srcdir</var> to refer to the toplevel source directory for
     49  1.7  mrg GCC; we use <var>objdir</var> to refer to the toplevel build/object directory.
     50  1.6  mrg 
     51  1.7  mrg    <p>If you obtained the sources via SVN, <var>srcdir</var> must refer to the top
     52  1.7  mrg <samp><span class="file">gcc</span></samp> directory, the one where the <samp><span class="file">MAINTAINERS</span></samp> file can be
     53  1.7  mrg found, and not its <samp><span class="file">gcc</span></samp> subdirectory, otherwise the build will fail.
     54  1.6  mrg 
     55  1.7  mrg    <p>If either <var>srcdir</var> or <var>objdir</var> is located on an automounted NFS
     56  1.7  mrg file system, the shell's built-in <samp><span class="command">pwd</span></samp> command will return
     57  1.1  mrg temporary pathnames.  Using these can lead to various sorts of build
     58  1.7  mrg problems.  To avoid this issue, set the <samp><span class="env">PWDCMD</span></samp> environment
     59  1.7  mrg variable to an automounter-aware <samp><span class="command">pwd</span></samp> command, e.g.,
     60  1.7  mrg <samp><span class="command">pawd</span></samp> or &lsquo;<samp><span class="samp">amq -w</span></samp>&rsquo;, during the configuration and build
     61  1.1  mrg phases.
     62  1.7  mrg 
     63  1.7  mrg    <p>First, we <strong>highly</strong> recommend that GCC be built into a
     64  1.1  mrg separate directory from the sources which does <strong>not</strong> reside
     65  1.1  mrg within the source tree.  This is how we generally build GCC; building
     66  1.7  mrg where <var>srcdir</var> == <var>objdir</var> should still work, but doesn't
     67  1.1  mrg get extensive testing; building where <var>objdir</var> is a subdirectory
     68  1.1  mrg of <var>srcdir</var> is unsupported.
     69  1.7  mrg 
     70  1.7  mrg    <p>If you have previously built GCC in the same directory for a
     71  1.7  mrg different target machine, do &lsquo;<samp><span class="samp">make distclean</span></samp>&rsquo; to delete all files
     72  1.7  mrg that might be invalid.  One of the files this deletes is <samp><span class="file">Makefile</span></samp>;
     73  1.7  mrg if &lsquo;<samp><span class="samp">make distclean</span></samp>&rsquo; complains that <samp><span class="file">Makefile</span></samp> does not exist
     74  1.7  mrg or issues a message like &ldquo;don't know how to make distclean&rdquo; it probably
     75  1.1  mrg means that the directory is already suitably clean.  However, with the
     76  1.1  mrg recommended method of building in a separate <var>objdir</var>, you should
     77  1.1  mrg simply use a different <var>objdir</var> for each target.
     78  1.7  mrg 
     79  1.7  mrg    <p>Second, when configuring a native system, either <samp><span class="command">cc</span></samp> or
     80  1.7  mrg <samp><span class="command">gcc</span></samp> must be in your path or you must set <samp><span class="env">CC</span></samp> in
     81  1.1  mrg your environment before running configure.  Otherwise the configuration
     82  1.1  mrg scripts may fail.
     83  1.1  mrg 
     84  1.7  mrg    <p>To configure GCC:
     85  1.1  mrg 
     86  1.7  mrg <pre class="smallexample">     % mkdir <var>objdir</var>
     87  1.7  mrg      % cd <var>objdir</var>
     88  1.7  mrg      % <var>srcdir</var>/configure [<var>options</var>] [<var>target</var>]
     89  1.7  mrg </pre>
     90  1.7  mrg    <h3 class="heading"><a name="TOC0"></a>Distributor options</h3>
     91  1.1  mrg 
     92  1.1  mrg <p>If you will be distributing binary versions of GCC, with modifications
     93  1.1  mrg to the source code, you should use the options described in this
     94  1.1  mrg section to make clear that your version contains modifications.
     95  1.7  mrg 
     96  1.7  mrg      <dl>
     97  1.7  mrg <dt><code>--with-pkgversion=</code><var>version</var><dd>Specify a string that identifies your package.  You may wish
     98  1.1  mrg to include a build number or build date.  This version string will be
     99  1.7  mrg included in the output of <samp><span class="command">gcc --version</span></samp>.  This suffix does
    100  1.7  mrg not replace the default version string, only the &lsquo;<samp><span class="samp">GCC</span></samp>&rsquo; part.
    101  1.7  mrg 
    102  1.7  mrg      <p>The default value is &lsquo;<samp><span class="samp">GCC</span></samp>&rsquo;.
    103  1.7  mrg 
    104  1.7  mrg      <br><dt><code>--with-bugurl=</code><var>url</var><dd>Specify the URL that users should visit if they wish to report a bug. 
    105  1.1  mrg You are of course welcome to forward bugs reported to you to the FSF,
    106  1.1  mrg if you determine that they are not bugs in your modifications.
    107  1.1  mrg 
    108  1.7  mrg      <p>The default value refers to the FSF's GCC bug tracker.
    109  1.7  mrg 
    110  1.7  mrg    </dl>
    111  1.7  mrg 
    112  1.7  mrg <h3 class="heading"><a name="TOC1"></a>Target specification</h3>
    113  1.7  mrg 
    114  1.7  mrg      <ul>
    115  1.7  mrg <li>GCC has code to correctly determine the correct value for <var>target</var>
    116  1.1  mrg for nearly all native systems.  Therefore, we highly recommend you do
    117  1.1  mrg not provide a configure target when configuring a native compiler.
    118  1.1  mrg 
    119  1.7  mrg      <li><var>target</var> must be specified as <samp><span class="option">--target=</span><var>target</var></samp>
    120  1.1  mrg when configuring a cross compiler; examples of valid targets would be
    121  1.1  mrg m68k-elf, sh-elf, etc.
    122  1.1  mrg 
    123  1.7  mrg      <li>Specifying just <var>target</var> instead of <samp><span class="option">--target=</span><var>target</var></samp>
    124  1.7  mrg implies that the host defaults to <var>target</var>. 
    125  1.7  mrg </ul>
    126  1.1  mrg 
    127  1.7  mrg <h3 class="heading"><a name="TOC2"></a>Options specification</h3>
    128  1.1  mrg 
    129  1.1  mrg <p>Use <var>options</var> to override several configure time options for
    130  1.7  mrg GCC.  A list of supported <var>options</var> follows; &lsquo;<samp><span class="samp">configure
    131  1.7  mrg --help</span></samp>&rsquo; may list other options, but those not listed below may not
    132  1.1  mrg work and should not normally be used.
    133  1.7  mrg 
    134  1.7  mrg    <p>Note that each <samp><span class="option">--enable</span></samp> option has a corresponding
    135  1.7  mrg <samp><span class="option">--disable</span></samp> option and that each <samp><span class="option">--with</span></samp> option has a
    136  1.7  mrg corresponding <samp><span class="option">--without</span></samp> option.
    137  1.7  mrg 
    138  1.7  mrg      <dl>
    139  1.7  mrg <dt><code>--prefix=</code><var>dirname</var><dd>Specify the toplevel installation
    140  1.1  mrg directory.  This is the recommended way to install the tools into a directory
    141  1.1  mrg other than the default.  The toplevel installation directory defaults to
    142  1.7  mrg <samp><span class="file">/usr/local</span></samp>.
    143  1.7  mrg 
    144  1.7  mrg      <p>We <strong>highly</strong> recommend against <var>dirname</var> being the same or a
    145  1.1  mrg subdirectory of <var>objdir</var> or vice versa.  If specifying a directory
    146  1.7  mrg beneath a user's home directory tree, some shells will not expand
    147  1.7  mrg <var>dirname</var> correctly if it contains the &lsquo;<samp><span class="samp">~</span></samp>&rsquo; metacharacter; use
    148  1.7  mrg <samp><span class="env">$HOME</span></samp> instead.
    149  1.7  mrg 
    150  1.7  mrg      <p>The following standard <samp><span class="command">autoconf</span></samp> options are supported.  Normally you
    151  1.1  mrg should not need to use these options.
    152  1.7  mrg           <dl>
    153  1.7  mrg <dt><code>--exec-prefix=</code><var>dirname</var><dd>Specify the toplevel installation directory for architecture-dependent
    154  1.1  mrg files.  The default is <samp><var>prefix</var></samp>.
    155  1.7  mrg 
    156  1.7  mrg           <br><dt><code>--bindir=</code><var>dirname</var><dd>Specify the installation directory for the executables called by users
    157  1.7  mrg (such as <samp><span class="command">gcc</span></samp> and <samp><span class="command">g++</span></samp>).  The default is
    158  1.7  mrg <samp><var>exec-prefix</var><span class="file">/bin</span></samp>.
    159  1.7  mrg 
    160  1.7  mrg           <br><dt><code>--libdir=</code><var>dirname</var><dd>Specify the installation directory for object code libraries and
    161  1.7  mrg internal data files of GCC.  The default is <samp><var>exec-prefix</var><span class="file">/lib</span></samp>.
    162  1.7  mrg 
    163  1.7  mrg           <br><dt><code>--libexecdir=</code><var>dirname</var><dd>Specify the installation directory for internal executables of GCC. 
    164  1.7  mrg The default is <samp><var>exec-prefix</var><span class="file">/libexec</span></samp>.
    165  1.7  mrg 
    166  1.7  mrg           <br><dt><code>--with-slibdir=</code><var>dirname</var><dd>Specify the installation directory for the shared libgcc library.  The
    167  1.1  mrg default is <samp><var>libdir</var></samp>.
    168  1.7  mrg 
    169  1.7  mrg           <br><dt><code>--datarootdir=</code><var>dirname</var><dd>Specify the root of the directory tree for read-only architecture-independent
    170  1.7  mrg data files referenced by GCC.  The default is <samp><var>prefix</var><span class="file">/share</span></samp>.
    171  1.7  mrg 
    172  1.7  mrg           <br><dt><code>--infodir=</code><var>dirname</var><dd>Specify the installation directory for documentation in info format. 
    173  1.7  mrg The default is <samp><var>datarootdir</var><span class="file">/info</span></samp>.
    174  1.7  mrg 
    175  1.7  mrg           <br><dt><code>--datadir=</code><var>dirname</var><dd>Specify the installation directory for some architecture-independent
    176  1.1  mrg data files referenced by GCC.  The default is <samp><var>datarootdir</var></samp>.
    177  1.7  mrg 
    178  1.7  mrg           <br><dt><code>--docdir=</code><var>dirname</var><dd>Specify the installation directory for documentation files (other
    179  1.7  mrg than Info) for GCC.  The default is <samp><var>datarootdir</var><span class="file">/doc</span></samp>.
    180  1.7  mrg 
    181  1.7  mrg           <br><dt><code>--htmldir=</code><var>dirname</var><dd>Specify the installation directory for HTML documentation files. 
    182  1.1  mrg The default is <samp><var>docdir</var></samp>.
    183  1.7  mrg 
    184  1.7  mrg           <br><dt><code>--pdfdir=</code><var>dirname</var><dd>Specify the installation directory for PDF documentation files. 
    185  1.1  mrg The default is <samp><var>docdir</var></samp>.
    186  1.7  mrg 
    187  1.7  mrg           <br><dt><code>--mandir=</code><var>dirname</var><dd>Specify the installation directory for manual pages.  The default is
    188  1.7  mrg <samp><var>datarootdir</var><span class="file">/man</span></samp>.  (Note that the manual pages are only extracts
    189  1.1  mrg from the full GCC manuals, which are provided in Texinfo format.  The manpages
    190  1.1  mrg are derived by an automatic conversion process from parts of the full
    191  1.1  mrg manual.)
    192  1.7  mrg 
    193  1.7  mrg           <br><dt><code>--with-gxx-include-dir=</code><var>dirname</var><dd>Specify
    194  1.1  mrg the installation directory for G++ header files.  The default depends
    195  1.1  mrg on other configuration options, and differs between cross and native
    196  1.1  mrg configurations.
    197  1.7  mrg 
    198  1.7  mrg           <br><dt><code>--with-specs=</code><var>specs</var><dd>Specify additional command line driver SPECS. 
    199  1.3  mrg This can be useful if you need to turn on a non-standard feature by
    200  1.7  mrg default without modifying the compiler's source code, for instance
    201  1.7  mrg <samp><span class="option">--with-specs=%{!fcommon:%{!fno-common:-fno-common}}</span></samp>. 
    202  1.3  mrg See &ldquo;Spec Files&rdquo; in the main manual
    203  1.3  mrg 
    204  1.7  mrg      </dl>
    205  1.7  mrg 
    206  1.7  mrg      <br><dt><code>--program-prefix=</code><var>prefix</var><dd>GCC supports some transformations of the names of its programs when
    207  1.1  mrg installing them.  This option prepends <var>prefix</var> to the names of
    208  1.1  mrg programs to install in <var>bindir</var> (see above).  For example, specifying
    209  1.7  mrg <samp><span class="option">--program-prefix=foo-</span></samp> would result in &lsquo;<samp><span class="samp">gcc</span></samp>&rsquo;
    210  1.7  mrg being installed as <samp><span class="file">/usr/local/bin/foo-gcc</span></samp>.
    211  1.7  mrg 
    212  1.7  mrg      <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>
    213  1.7  mrg (see above).  For example, specifying <samp><span class="option">--program-suffix=-3.1</span></samp>
    214  1.7  mrg would result in &lsquo;<samp><span class="samp">gcc</span></samp>&rsquo; being installed as
    215  1.7  mrg <samp><span class="file">/usr/local/bin/gcc-3.1</span></samp>.
    216  1.7  mrg 
    217  1.7  mrg      <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
    218  1.1  mrg of programs to install in <var>bindir</var> (see above).  <var>pattern</var> has to
    219  1.7  mrg consist of one or more basic &lsquo;<samp><span class="samp">sed</span></samp>&rsquo; editing commands, separated by
    220  1.7  mrg semicolons.  For example, if you want the &lsquo;<samp><span class="samp">gcc</span></samp>&rsquo; program name to be
    221  1.7  mrg transformed to the installed program <samp><span class="file">/usr/local/bin/myowngcc</span></samp> and
    222  1.7  mrg the &lsquo;<samp><span class="samp">g++</span></samp>&rsquo; program name to be transformed to
    223  1.7  mrg <samp><span class="file">/usr/local/bin/gspecial++</span></samp> without changing other program names,
    224  1.1  mrg you could use the pattern
    225  1.7  mrg <samp><span class="option">--program-transform-name='s/^gcc$/myowngcc/; s/^g++$/gspecial++/'</span></samp>
    226  1.1  mrg to achieve this effect.
    227  1.7  mrg 
    228  1.7  mrg      <p>All three options can be combined and used together, resulting in more
    229  1.1  mrg complex conversion patterns.  As a basic rule, <var>prefix</var> (and
    230  1.1  mrg <var>suffix</var>) are prepended (appended) before further transformations
    231  1.1  mrg can happen with a special transformation script <var>pattern</var>.
    232  1.7  mrg 
    233  1.7  mrg      <p>As currently implemented, this option only takes effect for native
    234  1.7  mrg builds; cross compiler binaries' names are not transformed even when a
    235  1.1  mrg transformation is explicitly asked for by one of these options.
    236  1.7  mrg 
    237  1.7  mrg      <p>For native builds, some of the installed programs are also installed
    238  1.1  mrg with the target alias in front of their name, as in
    239  1.7  mrg &lsquo;<samp><span class="samp">i686-pc-linux-gnu-gcc</span></samp>&rsquo;.  All of the above transformations happen
    240  1.1  mrg before the target alias is prepended to the name&mdash;so, specifying
    241  1.7  mrg <samp><span class="option">--program-prefix=foo-</span></samp> and <samp><span class="option">program-suffix=-3.1</span></samp>, the
    242  1.1  mrg resulting binary would be installed as
    243  1.7  mrg <samp><span class="file">/usr/local/bin/i686-pc-linux-gnu-foo-gcc-3.1</span></samp>.
    244  1.7  mrg 
    245  1.7  mrg      <p>As a last shortcoming, none of the installed Ada programs are
    246  1.1  mrg transformed yet, which will be fixed in some time.
    247  1.7  mrg 
    248  1.7  mrg      <br><dt><code>--with-local-prefix=</code><var>dirname</var><dd>Specify the
    249  1.1  mrg installation directory for local include files.  The default is
    250  1.7  mrg <samp><span class="file">/usr/local</span></samp>.  Specify this option if you want the compiler to
    251  1.7  mrg search directory <samp><var>dirname</var><span class="file">/include</span></samp> for locally installed
    252  1.7  mrg header files <em>instead</em> of <samp><span class="file">/usr/local/include</span></samp>.
    253  1.7  mrg 
    254  1.7  mrg      <p>You should specify <samp><span class="option">--with-local-prefix</span></samp> <strong>only</strong> if your
    255  1.7  mrg site has a different convention (not <samp><span class="file">/usr/local</span></samp>) for where to put
    256  1.1  mrg site-specific files.
    257  1.7  mrg 
    258  1.7  mrg      <p>The default value for <samp><span class="option">--with-local-prefix</span></samp> is <samp><span class="file">/usr/local</span></samp>
    259  1.7  mrg regardless of the value of <samp><span class="option">--prefix</span></samp>.  Specifying
    260  1.7  mrg <samp><span class="option">--prefix</span></samp> has no effect on which directory GCC searches for
    261  1.1  mrg local header files.  This may seem counterintuitive, but actually it is
    262  1.1  mrg logical.
    263  1.7  mrg 
    264  1.7  mrg      <p>The purpose of <samp><span class="option">--prefix</span></samp> is to specify where to <em>install
    265  1.7  mrg GCC</em>.  The local header files in <samp><span class="file">/usr/local/include</span></samp>&mdash;if you put
    266  1.1  mrg any in that directory&mdash;are not part of GCC.  They are part of other
    267  1.1  mrg programs&mdash;perhaps many others.  (GCC installs its own header files in
    268  1.7  mrg another directory which is based on the <samp><span class="option">--prefix</span></samp> value.)
    269  1.7  mrg 
    270  1.7  mrg      <p>Both the local-prefix include directory and the GCC-prefix include
    271  1.7  mrg directory are part of GCC's &ldquo;system include&rdquo; directories.  Although these
    272  1.1  mrg two directories are not fixed, they need to be searched in the proper
    273  1.1  mrg order for the correct processing of the include_next directive.  The
    274  1.1  mrg local-prefix include directory is searched before the GCC-prefix
    275  1.1  mrg include directory.  Another characteristic of system include directories
    276  1.1  mrg is that pedantic warnings are turned off for headers in these directories.
    277  1.7  mrg 
    278  1.7  mrg      <p>Some autoconf macros add <samp><span class="option">-I </span><var>directory</var></samp> options to the
    279  1.1  mrg compiler command line, to ensure that directories containing installed
    280  1.7  mrg packages' headers are searched.  When <var>directory</var> is one of GCC's
    281  1.1  mrg system include directories, GCC will ignore the option so that system
    282  1.1  mrg directories continue to be processed in the correct order.  This
    283  1.1  mrg may result in a search order different from what was specified but the
    284  1.1  mrg directory will still be searched.
    285  1.7  mrg 
    286  1.7  mrg      <p>GCC automatically searches for ordinary libraries using
    287  1.7  mrg <samp><span class="env">GCC_EXEC_PREFIX</span></samp>.  Thus, when the same installation prefix is
    288  1.1  mrg used for both GCC and packages, GCC will automatically search for
    289  1.1  mrg both headers and libraries.  This provides a configuration that is
    290  1.1  mrg easy to use.  GCC behaves in a manner similar to that when it is
    291  1.7  mrg installed as a system compiler in <samp><span class="file">/usr</span></samp>.
    292  1.7  mrg 
    293  1.7  mrg      <p>Sites that need to install multiple versions of GCC may not want to
    294  1.1  mrg use the above simple configuration.  It is possible to use the
    295  1.7  mrg <samp><span class="option">--program-prefix</span></samp>, <samp><span class="option">--program-suffix</span></samp> and
    296  1.7  mrg <samp><span class="option">--program-transform-name</span></samp> options to install multiple versions
    297  1.1  mrg into a single directory, but it may be simpler to use different prefixes
    298  1.7  mrg and the <samp><span class="option">--with-local-prefix</span></samp> option to specify the location of the
    299  1.1  mrg site-specific files for each version.  It will then be necessary for
    300  1.1  mrg users to specify explicitly the location of local site libraries
    301  1.7  mrg (e.g., with <samp><span class="env">LIBRARY_PATH</span></samp>).
    302  1.7  mrg 
    303  1.7  mrg      <p>The same value can be used for both <samp><span class="option">--with-local-prefix</span></samp> and
    304  1.7  mrg <samp><span class="option">--prefix</span></samp> provided it is not <samp><span class="file">/usr</span></samp>.  This can be used
    305  1.7  mrg to avoid the default search of <samp><span class="file">/usr/local/include</span></samp>.
    306  1.7  mrg 
    307  1.7  mrg      <p><strong>Do not</strong> specify <samp><span class="file">/usr</span></samp> as the <samp><span class="option">--with-local-prefix</span></samp>! 
    308  1.7  mrg The directory you use for <samp><span class="option">--with-local-prefix</span></samp> <strong>must not</strong>
    309  1.7  mrg contain any of the system's standard header files.  If it did contain
    310  1.1  mrg them, certain programs would be miscompiled (including GNU Emacs, on
    311  1.1  mrg certain targets), because this would override and nullify the header
    312  1.7  mrg file corrections made by the <samp><span class="command">fixincludes</span></samp> script.
    313  1.7  mrg 
    314  1.7  mrg      <p>Indications are that people who use this option use it based on mistaken
    315  1.1  mrg ideas of what it is for.  People use it as if it specified where to
    316  1.1  mrg install part of GCC.  Perhaps they make this assumption because
    317  1.1  mrg installing GCC creates the directory.
    318  1.7  mrg 
    319  1.7  mrg      <br><dt><code>--with-native-system-header-dir=</code><var>dirname</var><dd>Specifies that <var>dirname</var> is the directory that contains native system
    320  1.7  mrg header files, rather than <samp><span class="file">/usr/include</span></samp>.  This option is most useful
    321  1.3  mrg if you are creating a compiler that should be isolated from the system
    322  1.3  mrg as much as possible.  It is most commonly used with the
    323  1.7  mrg <samp><span class="option">--with-sysroot</span></samp> option and will cause GCC to search
    324  1.3  mrg <var>dirname</var> inside the system root specified by that option.
    325  1.7  mrg 
    326  1.7  mrg      <br><dt><code>--enable-shared[=</code><var>package</var><code>[,...]]</code><dd>Build shared versions of libraries, if shared libraries are supported on
    327  1.1  mrg the target platform.  Unlike GCC 2.95.x and earlier, shared libraries
    328  1.1  mrg are enabled by default on all platforms that support shared libraries.
    329  1.7  mrg 
    330  1.7  mrg      <p>If a list of packages is given as an argument, build shared libraries
    331  1.1  mrg only for the listed packages.  For other packages, only static libraries
    332  1.1  mrg will be built.  Package names currently recognized in the GCC tree are
    333  1.7  mrg &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
    334  1.7  mrg &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;,
    335  1.7  mrg &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;, &lsquo;<samp><span class="samp">libgo</span></samp>&rsquo;, and &lsquo;<samp><span class="samp">libobjc</span></samp>&rsquo;. 
    336  1.7  mrg Note &lsquo;<samp><span class="samp">libiberty</span></samp>&rsquo; does not support shared libraries at all.
    337  1.7  mrg 
    338  1.7  mrg      <p>Use <samp><span class="option">--disable-shared</span></samp> to build only static libraries.  Note that
    339  1.7  mrg <samp><span class="option">--disable-shared</span></samp> does not accept a list of package names as
    340  1.7  mrg argument, only <samp><span class="option">--enable-shared</span></samp> does.
    341  1.7  mrg 
    342  1.7  mrg      <p>Contrast with <samp><span class="option">--enable-host-shared</span></samp>, which affects <em>host</em>
    343  1.5  mrg code.
    344  1.7  mrg 
    345  1.7  mrg      <br><dt><code>--enable-host-shared</code><dd>Specify that the <em>host</em> code should be built into position-independent
    346  1.5  mrg machine code (with -fPIC), allowing it to be used within shared libraries,
    347  1.5  mrg but yielding a slightly slower compiler.
    348  1.7  mrg 
    349  1.7  mrg      <p>This option is required when building the libgccjit.so library.
    350  1.7  mrg 
    351  1.7  mrg      <p>Contrast with <samp><span class="option">--enable-shared</span></samp>, which affects <em>target</em>
    352  1.5  mrg libraries.
    353  1.7  mrg 
    354  1.7  mrg      <br><dt><code><a name="with_002dgnu_002das"></a>--with-gnu-as</code><dd>Specify that the compiler should assume that the
    355  1.1  mrg assembler it finds is the GNU assembler.  However, this does not modify
    356  1.1  mrg the rules to find an assembler and will result in confusion if the
    357  1.1  mrg assembler found is not actually the GNU assembler.  (Confusion may also
    358  1.1  mrg result if the compiler finds the GNU assembler but has not been
    359  1.7  mrg configured with <samp><span class="option">--with-gnu-as</span></samp>.)  If you have more than one
    360  1.1  mrg assembler installed on your system, you may want to use this option in
    361  1.7  mrg connection with <samp><span class="option">--with-as=</span><var>pathname</var></samp> or
    362  1.7  mrg <samp><span class="option">--with-build-time-tools=</span><var>pathname</var></samp>.
    363  1.7  mrg 
    364  1.7  mrg      <p>The following systems are the only ones where it makes a difference
    365  1.1  mrg whether you use the GNU assembler.  On any other system,
    366  1.7  mrg <samp><span class="option">--with-gnu-as</span></samp> has no effect.
    367  1.7  mrg 
    368  1.7  mrg           <ul>
    369  1.7  mrg <li>&lsquo;<samp><span class="samp">hppa1.0-</span><var>any</var><span class="samp">-</span><var>any</var></samp>&rsquo;
    370  1.7  mrg <li>&lsquo;<samp><span class="samp">hppa1.1-</span><var>any</var><span class="samp">-</span><var>any</var></samp>&rsquo;
    371  1.7  mrg <li>&lsquo;<samp><span class="samp">sparc-sun-solaris2.</span><var>any</var></samp>&rsquo;
    372  1.7  mrg <li>&lsquo;<samp><span class="samp">sparc64-</span><var>any</var><span class="samp">-solaris2.</span><var>any</var></samp>&rsquo;
    373  1.7  mrg </ul>
    374  1.7  mrg 
    375  1.7  mrg      <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
    376  1.1  mrg <var>pathname</var>, rather than the one found by the standard rules to find
    377  1.1  mrg an assembler, which are:
    378  1.7  mrg           <ul>
    379  1.7  mrg <li>Unless GCC is being built with a cross compiler, check the
    380  1.7  mrg <samp><var>libexec</var><span class="file">/gcc/</span><var>target</var><span class="file">/</span><var>version</var></samp> directory. 
    381  1.7  mrg <var>libexec</var> defaults to <samp><var>exec-prefix</var><span class="file">/libexec</span></samp>;
    382  1.1  mrg <var>exec-prefix</var> defaults to <var>prefix</var>, which
    383  1.7  mrg defaults to <samp><span class="file">/usr/local</span></samp> unless overridden by the
    384  1.7  mrg <samp><span class="option">--prefix=</span><var>pathname</var></samp> switch described above.  <var>target</var>
    385  1.7  mrg is the target system triple, such as &lsquo;<samp><span class="samp">sparc-sun-solaris2.7</span></samp>&rsquo;, and
    386  1.1  mrg <var>version</var> denotes the GCC version, such as 3.0.
    387  1.1  mrg 
    388  1.7  mrg           <li>If the target system is the same that you are building on, check
    389  1.7  mrg operating system specific directories (e.g. <samp><span class="file">/usr/ccs/bin</span></samp> on
    390  1.1  mrg Sun Solaris 2).
    391  1.1  mrg 
    392  1.7  mrg           <li>Check in the <samp><span class="env">PATH</span></samp> for a tool whose name is prefixed by the
    393  1.1  mrg target system triple.
    394  1.1  mrg 
    395  1.7  mrg           <li>Check in the <samp><span class="env">PATH</span></samp> for a tool whose name is not prefixed by the
    396  1.1  mrg target system triple, if the host and target system triple are
    397  1.1  mrg the same (in other words, we use a host tool if it can be used for
    398  1.7  mrg the target as well). 
    399  1.7  mrg </ul>
    400  1.1  mrg 
    401  1.7  mrg      <p>You may want to use <samp><span class="option">--with-as</span></samp> if no assembler
    402  1.1  mrg is installed in the directories listed above, or if you have multiple
    403  1.1  mrg assemblers installed and want to choose one that is not found by the
    404  1.1  mrg above rules.
    405  1.7  mrg 
    406  1.7  mrg      <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>
    407  1.1  mrg but for the linker.
    408  1.7  mrg 
    409  1.7  mrg      <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>
    410  1.1  mrg but for the linker.
    411  1.7  mrg 
    412  1.7  mrg      <br><dt><code>--with-stabs</code><dd>Specify that stabs debugging
    413  1.1  mrg information should be used instead of whatever format the host normally
    414  1.1  mrg uses.  Normally GCC uses the same debug format as the host system.
    415  1.7  mrg 
    416  1.7  mrg      <p>On MIPS based systems and on Alphas, you must specify whether you want
    417  1.1  mrg GCC to create the normal ECOFF debugging format, or to use BSD-style
    418  1.1  mrg stabs passed through the ECOFF symbol table.  The normal ECOFF debug
    419  1.1  mrg format cannot fully handle languages other than C.  BSD stabs format can
    420  1.1  mrg handle other languages, but it only works with the GNU debugger GDB.
    421  1.7  mrg 
    422  1.7  mrg      <p>Normally, GCC uses the ECOFF debugging format by default; if you
    423  1.7  mrg prefer BSD stabs, specify <samp><span class="option">--with-stabs</span></samp> when you configure GCC.
    424  1.7  mrg 
    425  1.7  mrg      <p>No matter which default you choose when you configure GCC, the user
    426  1.7  mrg can use the <samp><span class="option">-gcoff</span></samp> and <samp><span class="option">-gstabs+</span></samp> options to specify explicitly
    427  1.1  mrg the debug format for a particular compilation.
    428  1.7  mrg 
    429  1.7  mrg      <p><samp><span class="option">--with-stabs</span></samp> is meaningful on the ISC system on the 386, also, if
    430  1.7  mrg <samp><span class="option">--with-gas</span></samp> is used.  It selects use of stabs debugging
    431  1.1  mrg information embedded in COFF output.  This kind of debugging information
    432  1.1  mrg supports C++ well; ordinary COFF debugging information does not.
    433  1.7  mrg 
    434  1.7  mrg      <p><samp><span class="option">--with-stabs</span></samp> is also meaningful on 386 systems running SVR4.  It
    435  1.1  mrg selects use of stabs debugging information embedded in ELF output.  The
    436  1.1  mrg C++ compiler currently (2.6.0) does not support the DWARF debugging
    437  1.1  mrg information normally used on 386 SVR4 platforms; stabs provide a
    438  1.1  mrg workable alternative.  This requires gas and gdb, as the normal SVR4
    439  1.1  mrg tools can not generate or interpret stabs.
    440  1.7  mrg 
    441  1.7  mrg      <br><dt><code>--with-tls=</code><var>dialect</var><dd>Specify the default TLS dialect, for systems were there is a choice. 
    442  1.3  mrg For ARM targets, possible values for <var>dialect</var> are <code>gnu</code> or
    443  1.3  mrg <code>gnu2</code>, which select between the original GNU dialect and the GNU TLS
    444  1.3  mrg descriptor-based dialect.
    445  1.7  mrg 
    446  1.7  mrg      <br><dt><code>--enable-multiarch</code><dd>Specify whether to enable or disable multiarch support.  The default is
    447  1.3  mrg to check for glibc start files in a multiarch location, and enable it
    448  1.3  mrg if the files are found.  The auto detection is enabled for native builds,
    449  1.7  mrg and for cross builds configured with <samp><span class="option">--with-sysroot</span></samp>, and without
    450  1.7  mrg <samp><span class="option">--with-native-system-header-dir</span></samp>. 
    451  1.3  mrg More documentation about multiarch can be found at
    452  1.7  mrg <a href="https://wiki.debian.org/Multiarch">https://wiki.debian.org/Multiarch</a>.
    453  1.7  mrg 
    454  1.7  mrg      <br><dt><code>--enable-sjlj-exceptions</code><dd>Force use of the <code>setjmp</code>/<code>longjmp</code>-based scheme for exceptions. 
    455  1.7  mrg &lsquo;<samp><span class="samp">configure</span></samp>&rsquo; ordinarily picks the correct value based on the platform. 
    456  1.6  mrg Only use this option if you are sure you need a different setting.
    457  1.7  mrg 
    458  1.7  mrg      <br><dt><code>--enable-vtable-verify</code><dd>Specify whether to enable or disable the vtable verification feature. 
    459  1.5  mrg Enabling this feature causes libstdc++ to be built with its virtual calls
    460  1.5  mrg in verifiable mode.  This means that, when linked with libvtv, every
    461  1.5  mrg virtual call in libstdc++ will verify the vtable pointer through which the
    462  1.5  mrg call will be made before actually making the call.  If not linked with libvtv,
    463  1.7  mrg the verifier will call stub functions (in libstdc++ itself) and do nothing. 
    464  1.5  mrg If vtable verification is disabled, then libstdc++ is not built with its
    465  1.5  mrg virtual calls in verifiable mode at all.  However the libvtv library will
    466  1.7  mrg still be built (see <samp><span class="option">--disable-libvtv</span></samp> to turn off building libvtv). 
    467  1.7  mrg <samp><span class="option">--disable-vtable-verify</span></samp> is the default.
    468  1.7  mrg 
    469  1.7  mrg      <br><dt><code>--disable-multilib</code><dd>Specify that multiple target
    470  1.1  mrg libraries to support different target variants, calling
    471  1.1  mrg conventions, etc. should not be built.  The default is to build a
    472  1.1  mrg predefined set of them.
    473  1.7  mrg 
    474  1.7  mrg      <p>Some targets provide finer-grained control over which multilibs are built
    475  1.7  mrg (e.g., <samp><span class="option">--disable-softfloat</span></samp>):
    476  1.7  mrg           <dl>
    477  1.7  mrg <dt><code>arm-*-*</code><dd>fpu, 26bit, underscore, interwork, biendian, nofmult.
    478  1.7  mrg 
    479  1.7  mrg           <br><dt><code>m68*-*-*</code><dd>softfloat, m68881, m68000, m68020.
    480  1.7  mrg 
    481  1.7  mrg           <br><dt><code>mips*-*-*</code><dd>single-float, biendian, softfloat.
    482  1.7  mrg 
    483  1.7  mrg           <br><dt><code>powerpc*-*-*, rs6000*-*-*</code><dd>aix64, pthread, softfloat, powercpu, powerpccpu, powerpcos, biendian,
    484  1.1  mrg sysv, aix.
    485  1.1  mrg 
    486  1.7  mrg      </dl>
    487  1.7  mrg 
    488  1.7  mrg      <br><dt><code>--with-multilib-list=</code><var>list</var><dt><code>--without-multilib-list</code><dd>Specify what multilibs to build. 
    489  1.7  mrg Currently only implemented for arm*-*-*, sh*-*-* and x86-64-*-linux*.
    490  1.7  mrg 
    491  1.7  mrg           <dl>
    492  1.7  mrg <dt><code>arm*-*-*</code><dd><var>list</var> is either <code>default</code> or <code>aprofile</code>.  Specifying
    493  1.7  mrg <code>default</code> is equivalent to omitting this option while specifying
    494  1.7  mrg <code>aprofile</code> builds multilibs for each combination of ISA (<code>-marm</code> or
    495  1.7  mrg <code>-mthumb</code>), architecture (<code>-march=armv7-a</code>, <code>-march=armv7ve</code>,
    496  1.7  mrg or <code>-march=armv8-a</code>), FPU available (none, <code>-mfpu=vfpv3-d16</code>,
    497  1.7  mrg <code>-mfpu=neon</code>, <code>-mfpu=vfpv4-d16</code>, <code>-mfpu=neon-vfpv4</code> or
    498  1.7  mrg <code>-mfpu=neon-fp-armv8</code> depending on architecture) and floating-point ABI
    499  1.7  mrg (<code>-mfloat-abi=softfp</code> or <code>-mfloat-abi=hard</code>).
    500  1.7  mrg 
    501  1.7  mrg           <br><dt><code>sh*-*-*</code><dd><var>list</var> is a comma separated list of CPU names.  These must be of the
    502  1.1  mrg form <code>sh*</code> or <code>m*</code> (in which case they match the compiler option
    503  1.1  mrg for that processor).  The list should not contain any endian options -
    504  1.7  mrg these are handled by <samp><span class="option">--with-endian</span></samp>.
    505  1.7  mrg 
    506  1.7  mrg           <p>If <var>list</var> is empty, then there will be no multilibs for extra
    507  1.1  mrg processors.  The multilib for the secondary endian remains enabled.
    508  1.7  mrg 
    509  1.7  mrg           <p>As a special case, if an entry in the list starts with a <code>!</code>
    510  1.7  mrg (exclamation point), then it is added to the list of excluded multilibs. 
    511  1.7  mrg Entries of this sort should be compatible with &lsquo;<samp><span class="samp">MULTILIB_EXCLUDES</span></samp>&rsquo;
    512  1.1  mrg (once the leading <code>!</code> has been stripped).
    513  1.7  mrg 
    514  1.7  mrg           <p>If <samp><span class="option">--with-multilib-list</span></samp> is not given, then a default set of
    515  1.7  mrg multilibs is selected based on the value of <samp><span class="option">--target</span></samp>.  This is
    516  1.1  mrg usually the complete set of libraries, but some targets imply a more
    517  1.1  mrg specialized subset.
    518  1.7  mrg 
    519  1.7  mrg           <p>Example 1: to configure a compiler for SH4A only, but supporting both
    520  1.6  mrg endians, with little endian being the default:
    521  1.7  mrg           <pre class="smallexample">               --with-cpu=sh4a --with-endian=little,big --with-multilib-list=
    522  1.7  mrg </pre>
    523  1.7  mrg           <p>Example 2: to configure a compiler for both SH4A and SH4AL-DSP, but with
    524  1.1  mrg only little endian SH4AL:
    525  1.7  mrg           <pre class="smallexample">               --with-cpu=sh4a --with-endian=little,big \
    526  1.7  mrg                --with-multilib-list=sh4al,!mb/m4al
    527  1.7  mrg </pre>
    528  1.7  mrg           <br><dt><code>x86-64-*-linux*</code><dd><var>list</var> is a comma separated list of <code>m32</code>, <code>m64</code> and
    529  1.3  mrg <code>mx32</code> to enable 32-bit, 64-bit and x32 run-time libraries,
    530  1.3  mrg respectively.  If <var>list</var> is empty, then there will be no multilibs
    531  1.3  mrg and only the default run-time library will be enabled.
    532  1.7  mrg 
    533  1.7  mrg           <p>If <samp><span class="option">--with-multilib-list</span></samp> is not given, then only 32-bit and
    534  1.7  mrg 64-bit run-time libraries will be enabled. 
    535  1.3  mrg </dl>
    536  1.3  mrg 
    537  1.7  mrg      <br><dt><code>--with-endian=</code><var>endians</var><dd>Specify what endians to use. 
    538  1.1  mrg Currently only implemented for sh*-*-*.
    539  1.7  mrg 
    540  1.7  mrg      <p><var>endians</var> may be one of the following:
    541  1.7  mrg           <dl>
    542  1.7  mrg <dt><code>big</code><dd>Use big endian exclusively. 
    543  1.7  mrg <br><dt><code>little</code><dd>Use little endian exclusively. 
    544  1.7  mrg <br><dt><code>big,little</code><dd>Use big endian by default.  Provide a multilib for little endian. 
    545  1.7  mrg <br><dt><code>little,big</code><dd>Use little endian by default.  Provide a multilib for big endian. 
    546  1.1  mrg </dl>
    547  1.1  mrg 
    548  1.7  mrg      <br><dt><code>--enable-threads</code><dd>Specify that the target
    549  1.1  mrg supports threads.  This affects the Objective-C compiler and runtime
    550  1.7  mrg library, and exception handling for other languages like C++ and Java. 
    551  1.1  mrg On some systems, this is the default.
    552  1.7  mrg 
    553  1.7  mrg      <p>In general, the best (and, in many cases, the only known) threading
    554  1.1  mrg model available will be configured for use.  Beware that on some
    555  1.1  mrg systems, GCC has not been taught what threading models are generally
    556  1.7  mrg available for the system.  In this case, <samp><span class="option">--enable-threads</span></samp> is an
    557  1.7  mrg alias for <samp><span class="option">--enable-threads=single</span></samp>.
    558  1.7  mrg 
    559  1.7  mrg      <br><dt><code>--disable-threads</code><dd>Specify that threading support should be disabled for the system. 
    560  1.7  mrg This is an alias for <samp><span class="option">--enable-threads=single</span></samp>.
    561  1.7  mrg 
    562  1.7  mrg      <br><dt><code>--enable-threads=</code><var>lib</var><dd>Specify that
    563  1.1  mrg <var>lib</var> is the thread support library.  This affects the Objective-C
    564  1.1  mrg compiler and runtime library, and exception handling for other languages
    565  1.1  mrg like C++ and Java.  The possibilities for <var>lib</var> are:
    566  1.7  mrg 
    567  1.7  mrg           <dl>
    568  1.7  mrg <dt><code>aix</code><dd>AIX thread support. 
    569  1.7  mrg <br><dt><code>dce</code><dd>DCE thread support. 
    570  1.7  mrg <br><dt><code>lynx</code><dd>LynxOS thread support. 
    571  1.7  mrg <br><dt><code>mipssde</code><dd>MIPS SDE thread support. 
    572  1.7  mrg <br><dt><code>no</code><dd>This is an alias for &lsquo;<samp><span class="samp">single</span></samp>&rsquo;. 
    573  1.7  mrg <br><dt><code>posix</code><dd>Generic POSIX/Unix98 thread support. 
    574  1.7  mrg <br><dt><code>rtems</code><dd>RTEMS thread support. 
    575  1.7  mrg <br><dt><code>single</code><dd>Disable thread support, should work for all platforms. 
    576  1.7  mrg <br><dt><code>tpf</code><dd>TPF thread support. 
    577  1.7  mrg <br><dt><code>vxworks</code><dd>VxWorks thread support. 
    578  1.7  mrg <br><dt><code>win32</code><dd>Microsoft Win32 API thread support. 
    579  1.1  mrg </dl>
    580  1.1  mrg 
    581  1.7  mrg      <br><dt><code>--enable-tls</code><dd>Specify that the target supports TLS (Thread Local Storage).  Usually
    582  1.1  mrg configure can correctly determine if TLS is supported.  In cases where
    583  1.1  mrg it guesses incorrectly, TLS can be explicitly enabled or disabled with
    584  1.7  mrg <samp><span class="option">--enable-tls</span></samp> or <samp><span class="option">--disable-tls</span></samp>.  This can happen if
    585  1.1  mrg the assembler supports TLS but the C library does not, or if the
    586  1.1  mrg assumptions made by the configure test are incorrect.
    587  1.7  mrg 
    588  1.7  mrg      <br><dt><code>--disable-tls</code><dd>Specify that the target does not support TLS. 
    589  1.7  mrg This is an alias for <samp><span class="option">--enable-tls=no</span></samp>.
    590  1.7  mrg 
    591  1.7  mrg      <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. 
    592  1.7  mrg <var>cpu</var> will be used as the default value of the <samp><span class="option">-mcpu=</span></samp> switch. 
    593  1.5  mrg This option is only supported on some targets, including ARC, ARM, i386, M68k,
    594  1.7  mrg PowerPC, and SPARC.  It is mandatory for ARC.  The <samp><span class="option">--with-cpu-32</span></samp> and
    595  1.7  mrg <samp><span class="option">--with-cpu-64</span></samp> options specify separate default CPUs for
    596  1.1  mrg 32-bit and 64-bit modes; these options are only supported for i386,
    597  1.7  mrg x86-64, PowerPC, and SPARC.
    598  1.7  mrg 
    599  1.7  mrg      <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>,
    600  1.7  mrg <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>
    601  1.7  mrg options and for <samp><span class="option">-mhard-float</span></samp> or <samp><span class="option">-msoft-float</span></samp>.  As with
    602  1.7  mrg <samp><span class="option">--with-cpu</span></samp>, which switches will be accepted and acceptable values
    603  1.1  mrg of the arguments depend on the target.
    604  1.7  mrg 
    605  1.7  mrg      <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>. 
    606  1.1  mrg This option is only supported on ARM targets.
    607  1.7  mrg 
    608  1.7  mrg      <br><dt><code>--with-stack-offset=</code><var>num</var><dd>This option sets the default for the -mstack-offset=<var>num</var> option,
    609  1.3  mrg and will thus generally also control the setting of this option for
    610  1.3  mrg libraries.  This option is only supported on Epiphany targets.
    611  1.7  mrg 
    612  1.7  mrg      <br><dt><code>--with-fpmath=</code><var>isa</var><dd>This options sets <samp><span class="option">-mfpmath=sse</span></samp> by default and specifies the default
    613  1.7  mrg ISA for floating-point arithmetics.  You can select either &lsquo;<samp><span class="samp">sse</span></samp>&rsquo; which
    614  1.7  mrg enables <samp><span class="option">-msse2</span></samp> or &lsquo;<samp><span class="samp">avx</span></samp>&rsquo; which enables <samp><span class="option">-mavx</span></samp> by default. 
    615  1.3  mrg This option is only supported on i386 and x86-64 targets.
    616  1.7  mrg 
    617  1.7  mrg      <br><dt><code>--with-fp-32=</code><var>mode</var><dd>On MIPS targets, set the default value for the <samp><span class="option">-mfp</span></samp> option when using
    618  1.5  mrg the o32 ABI.  The possibilities for <var>mode</var> are:
    619  1.7  mrg           <dl>
    620  1.7  mrg <dt><code>32</code><dd>Use the o32 FP32 ABI extension, as with the <samp><span class="option">-mfp32</span></samp> command-line
    621  1.7  mrg option. 
    622  1.7  mrg <br><dt><code>xx</code><dd>Use the o32 FPXX ABI extension, as with the <samp><span class="option">-mfpxx</span></samp> command-line
    623  1.7  mrg option. 
    624  1.7  mrg <br><dt><code>64</code><dd>Use the o32 FP64 ABI extension, as with the <samp><span class="option">-mfp64</span></samp> command-line
    625  1.7  mrg option. 
    626  1.5  mrg </dl>
    627  1.7  mrg      In the absence of this configuration option the default is to use the o32
    628  1.5  mrg FP32 ABI extension.
    629  1.7  mrg 
    630  1.7  mrg      <br><dt><code>--with-odd-spreg-32</code><dd>On MIPS targets, set the <samp><span class="option">-modd-spreg</span></samp> option by default when using
    631  1.5  mrg the o32 ABI.
    632  1.7  mrg 
    633  1.7  mrg      <br><dt><code>--without-odd-spreg-32</code><dd>On MIPS targets, set the <samp><span class="option">-mno-odd-spreg</span></samp> option by default when using
    634  1.5  mrg the o32 ABI.  This is normally used in conjunction with
    635  1.7  mrg <samp><span class="option">--with-fp-32=64</span></samp> in order to target the o32 FP64A ABI extension.
    636  1.7  mrg 
    637  1.7  mrg      <br><dt><code>--with-nan=</code><var>encoding</var><dd>On MIPS targets, set the default encoding convention to use for the
    638  1.5  mrg special not-a-number (NaN) IEEE 754 floating-point data.  The
    639  1.5  mrg possibilities for <var>encoding</var> are:
    640  1.7  mrg           <dl>
    641  1.7  mrg <dt><code>legacy</code><dd>Use the legacy encoding, as with the <samp><span class="option">-mnan=legacy</span></samp> command-line
    642  1.7  mrg option. 
    643  1.7  mrg <br><dt><code>2008</code><dd>Use the 754-2008 encoding, as with the <samp><span class="option">-mnan=2008</span></samp> command-line
    644  1.7  mrg option. 
    645  1.5  mrg </dl>
    646  1.7  mrg      To use this configuration option you must have an assembler version
    647  1.7  mrg installed that supports the <samp><span class="option">-mnan=</span></samp> command-line option too. 
    648  1.5  mrg In the absence of this configuration option the default convention is
    649  1.7  mrg the legacy encoding, as when neither of the <samp><span class="option">-mnan=2008</span></samp> and
    650  1.7  mrg <samp><span class="option">-mnan=legacy</span></samp> command-line options has been used.
    651  1.7  mrg 
    652  1.7  mrg      <br><dt><code>--with-divide=</code><var>type</var><dd>Specify how the compiler should generate code for checking for
    653  1.7  mrg division by zero.  This option is only supported on the MIPS target. 
    654  1.1  mrg The possibilities for <var>type</var> are:
    655  1.7  mrg           <dl>
    656  1.7  mrg <dt><code>traps</code><dd>Division by zero checks use conditional traps (this is the default on
    657  1.7  mrg systems that support conditional traps). 
    658  1.7  mrg <br><dt><code>breaks</code><dd>Division by zero checks use the break instruction. 
    659  1.1  mrg </dl>
    660  1.1  mrg 
    661  1.7  mrg      <!-- If you make -with-llsc the default for additional targets, -->
    662  1.7  mrg      <!-- update the -with-llsc description in the MIPS section below. -->
    663  1.7  mrg      <br><dt><code>--with-llsc</code><dd>On MIPS targets, make <samp><span class="option">-mllsc</span></samp> the default when no
    664  1.7  mrg <samp><span class="option">-mno-llsc</span></samp> option is passed.  This is the default for
    665  1.1  mrg Linux-based targets, as the kernel will emulate them if the ISA does
    666  1.1  mrg not provide them.
    667  1.7  mrg 
    668  1.7  mrg      <br><dt><code>--without-llsc</code><dd>On MIPS targets, make <samp><span class="option">-mno-llsc</span></samp> the default when no
    669  1.7  mrg <samp><span class="option">-mllsc</span></samp> option is passed.
    670  1.7  mrg 
    671  1.7  mrg      <br><dt><code>--with-synci</code><dd>On MIPS targets, make <samp><span class="option">-msynci</span></samp> the default when no
    672  1.7  mrg <samp><span class="option">-mno-synci</span></samp> option is passed.
    673  1.7  mrg 
    674  1.7  mrg      <br><dt><code>--without-synci</code><dd>On MIPS targets, make <samp><span class="option">-mno-synci</span></samp> the default when no
    675  1.7  mrg <samp><span class="option">-msynci</span></samp> option is passed.  This is the default.
    676  1.7  mrg 
    677  1.7  mrg      <br><dt><code>--with-mips-plt</code><dd>On MIPS targets, make use of copy relocations and PLTs. 
    678  1.1  mrg These features are extensions to the traditional
    679  1.1  mrg SVR4-based MIPS ABIs and require support from GNU binutils
    680  1.1  mrg and the runtime C library.
    681  1.7  mrg 
    682  1.7  mrg      <br><dt><code>--enable-__cxa_atexit</code><dd>Define if you want to use __cxa_atexit, rather than atexit, to
    683  1.7  mrg register C++ destructors for local statics and global objects. 
    684  1.1  mrg This is essential for fully standards-compliant handling of
    685  1.1  mrg destructors, but requires __cxa_atexit in libc.  This option is currently
    686  1.1  mrg only available on systems with GNU libc.  When enabled, this will cause
    687  1.7  mrg <samp><span class="option">-fuse-cxa-atexit</span></samp> to be passed by default.
    688  1.7  mrg 
    689  1.7  mrg      <br><dt><code>--enable-gnu-indirect-function</code><dd>Define if you want to enable the <code>ifunc</code> attribute.  This option is
    690  1.3  mrg currently only available on systems with GNU libc on certain targets.
    691  1.7  mrg 
    692  1.7  mrg      <br><dt><code>--enable-target-optspace</code><dd>Specify that target
    693  1.7  mrg libraries should be optimized for code space instead of code speed. 
    694  1.1  mrg This is the default for the m32r platform.
    695  1.7  mrg 
    696  1.7  mrg      <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
    697  1.7  mrg in <samp><var>prefix</var><span class="file">/</span><var>dirname</var><span class="file">/cpp</span></samp>, in addition to <var>bindir</var>.
    698  1.7  mrg 
    699  1.7  mrg      <br><dt><code>--enable-comdat</code><dd>Enable COMDAT group support.  This is primarily used to override the
    700  1.1  mrg automatically detected value.
    701  1.7  mrg 
    702  1.7  mrg      <br><dt><code>--enable-initfini-array</code><dd>Force the use of sections <code>.init_array</code> and <code>.fini_array</code>
    703  1.1  mrg (instead of <code>.init</code> and <code>.fini</code>) for constructors and
    704  1.7  mrg destructors.  Option <samp><span class="option">--disable-initfini-array</span></samp> has the
    705  1.1  mrg opposite effect.  If neither option is specified, the configure script
    706  1.1  mrg will try to guess whether the <code>.init_array</code> and
    707  1.1  mrg <code>.fini_array</code> sections are supported and, if they are, use them.
    708  1.7  mrg 
    709  1.7  mrg      <br><dt><code>--enable-link-mutex</code><dd>When building GCC, use a mutex to avoid linking the compilers for
    710  1.5  mrg multiple languages at the same time, to avoid thrashing on build
    711  1.5  mrg systems with limited free memory.  The default is not to use such a mutex.
    712  1.7  mrg 
    713  1.7  mrg      <br><dt><code>--enable-maintainer-mode</code><dd>The build rules that regenerate the Autoconf and Automake output files as
    714  1.7  mrg well as the GCC master message catalog <samp><span class="file">gcc.pot</span></samp> are normally
    715  1.1  mrg disabled.  This is because it can only be rebuilt if the complete source
    716  1.1  mrg tree is present.  If you have changed the sources and want to rebuild the
    717  1.7  mrg catalog, configuring with <samp><span class="option">--enable-maintainer-mode</span></samp> will enable
    718  1.1  mrg this.  Note that you need a recent version of the <code>gettext</code> tools
    719  1.1  mrg to do so.
    720  1.7  mrg 
    721  1.7  mrg      <br><dt><code>--disable-bootstrap</code><dd>For a native build, the default configuration is to perform
    722  1.7  mrg a 3-stage bootstrap of the compiler when &lsquo;<samp><span class="samp">make</span></samp>&rsquo; is invoked,
    723  1.1  mrg testing that GCC can compile itself correctly.  If you want to disable
    724  1.7  mrg this process, you can configure with <samp><span class="option">--disable-bootstrap</span></samp>.
    725  1.7  mrg 
    726  1.7  mrg      <br><dt><code>--enable-bootstrap</code><dd>In special cases, you may want to perform a 3-stage build
    727  1.7  mrg even if the target and host triplets are different. 
    728  1.1  mrg This is possible when the host can run code compiled for
    729  1.7  mrg the target (e.g. host is i686-linux, target is i486-linux). 
    730  1.1  mrg Starting from GCC 4.2, to do this you have to configure explicitly
    731  1.7  mrg with <samp><span class="option">--enable-bootstrap</span></samp>.
    732  1.7  mrg 
    733  1.7  mrg      <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
    734  1.1  mrg info manuals and man pages that are built from the .texi files are present
    735  1.1  mrg in the SVN development tree.  When building GCC from that development tree,
    736  1.1  mrg or from one of our snapshots, those generated files are placed in your
    737  1.1  mrg build directory, which allows for the source to be in a readonly
    738  1.1  mrg directory.
    739  1.7  mrg 
    740  1.7  mrg      <p>If you configure with <samp><span class="option">--enable-generated-files-in-srcdir</span></samp> then those
    741  1.1  mrg generated files will go into the source directory.  This is mainly intended
    742  1.1  mrg for generating release or prerelease tarballs of the GCC sources, since it
    743  1.1  mrg is not a requirement that the users of source releases to have flex, Bison,
    744  1.1  mrg or makeinfo.
    745  1.7  mrg 
    746  1.7  mrg      <br><dt><code>--enable-version-specific-runtime-libs</code><dd>Specify
    747  1.1  mrg that runtime libraries should be installed in the compiler specific
    748  1.7  mrg subdirectory (<samp><var>libdir</var><span class="file">/gcc</span></samp>) rather than the usual places.  In
    749  1.7  mrg addition, &lsquo;<samp><span class="samp">libstdc++</span></samp>&rsquo;'s include files will be installed into
    750  1.1  mrg <samp><var>libdir</var></samp> unless you overruled it by using
    751  1.7  mrg <samp><span class="option">--with-gxx-include-dir=</span><var>dirname</var></samp>.  Using this option is
    752  1.1  mrg particularly useful if you intend to use several versions of GCC in
    753  1.7  mrg parallel.  This is currently supported by &lsquo;<samp><span class="samp">libgfortran</span></samp>&rsquo;,
    754  1.7  mrg &lsquo;<samp><span class="samp">libjava</span></samp>&rsquo;, &lsquo;<samp><span class="samp">libstdc++</span></samp>&rsquo;, and &lsquo;<samp><span class="samp">libobjc</span></samp>&rsquo;.
    755  1.7  mrg 
    756  1.7  mrg      <br><dt><code><a name="WithAixSoname"></a>--with-aix-soname=&lsquo;</code><samp><span class="samp">aix</span></samp><code>&rsquo;, &lsquo;</code><samp><span class="samp">svr4</span></samp><code>&rsquo; or &lsquo;</code><samp><span class="samp">both</span></samp><code>&rsquo;</code><dd>Traditional AIX shared library versioning (versioned <code>Shared Object</code>
    757  1.5  mrg files as members of unversioned <code>Archive Library</code> files named
    758  1.7  mrg &lsquo;<samp><span class="samp">lib.a</span></samp>&rsquo;) causes numerous headaches for package managers. However,
    759  1.5  mrg <code>Import Files</code> as members of <code>Archive Library</code> files allow for
    760  1.5  mrg <strong>filename-based versioning</strong> of shared libraries as seen on Linux/SVR4,
    761  1.7  mrg where this is called the "SONAME". But as they prevent static linking,
    762  1.5  mrg <code>Import Files</code> may be used with <code>Runtime Linking</code> only, where the
    763  1.7  mrg linker does search for &lsquo;<samp><span class="samp">libNAME.so</span></samp>&rsquo; before &lsquo;<samp><span class="samp">libNAME.a</span></samp>&rsquo; library
    764  1.7  mrg filenames with the &lsquo;<samp><span class="samp">-lNAME</span></samp>&rsquo; linker flag.
    765  1.7  mrg 
    766  1.7  mrg      <p><a name="AixLdCommand"></a>For detailed information please refer to the AIX
    767  1.7  mrg <a href="http://www-01.ibm.com/support/knowledgecenter/search/%22the%20ld%20command%2C%20also%20called%20the%20linkage%20editor%20or%20binder%22">ld Command</a> reference.
    768  1.7  mrg 
    769  1.7  mrg      <p>As long as shared library creation is enabled, upon:
    770  1.7  mrg           <dl>
    771  1.7  mrg <dt><code>--with-aix-soname=aix</code><br><dt><code>--with-aix-soname=both</code><dd> A (traditional AIX) <code>Shared Archive Library</code> file is created:
    772  1.7  mrg                <ul>
    773  1.7  mrg   <li>using the &lsquo;<samp><span class="samp">libNAME.a</span></samp>&rsquo; filename scheme
    774  1.7  mrg   <li>with the <code>Shared Object</code> file as archive member named
    775  1.7  mrg   &lsquo;<samp><span class="samp">libNAME.so.V</span></samp>&rsquo; (except for &lsquo;<samp><span class="samp">libgcc_s</span></samp>&rsquo;, where the <code>Shared
    776  1.7  mrg   Object</code> file is named &lsquo;<samp><span class="samp">shr.o</span></samp>&rsquo; for backwards compatibility), which
    777  1.7  mrg                     <ul>
    778  1.7  mrg    <li>is used for runtime loading from inside the &lsquo;<samp><span class="samp">libNAME.a</span></samp>&rsquo; file
    779  1.7  mrg    <li>is used for dynamic loading via
    780  1.7  mrg    <code>dlopen("libNAME.a(libNAME.so.V)", RTLD_MEMBER)</code>
    781  1.7  mrg    <li>is used for shared linking
    782  1.7  mrg    <li>is used for static linking, so no separate <code>Static Archive
    783  1.5  mrg    Library</code> file is needed
    784  1.7  mrg   </ul>
    785  1.7  mrg                 </ul>
    786  1.7  mrg           <br><dt><code>--with-aix-soname=both</code><br><dt><code>--with-aix-soname=svr4</code><dd> A (second) <code>Shared Archive Library</code> file is created:
    787  1.7  mrg                <ul>
    788  1.7  mrg  <li>using the &lsquo;<samp><span class="samp">libNAME.so.V</span></samp>&rsquo; filename scheme
    789  1.7  mrg  <li>with the <code>Shared Object</code> file as archive member named
    790  1.7  mrg  &lsquo;<samp><span class="samp">shr.o</span></samp>&rsquo;, which
    791  1.7  mrg                     <ul>
    792  1.7  mrg    <li>is created with the <code>-G linker flag</code>
    793  1.7  mrg    <li>has the <code>F_LOADONLY</code> flag set
    794  1.7  mrg    <li>is used for runtime loading from inside the &lsquo;<samp><span class="samp">libNAME.so.V</span></samp>&rsquo; file
    795  1.7  mrg    <li>is used for dynamic loading via <code>dlopen("libNAME.so.V(shr.o)",
    796  1.5  mrg    RTLD_MEMBER)</code>
    797  1.7  mrg   </ul>
    798  1.7  mrg                 <li>with the <code>Import File</code> as archive member named &lsquo;<samp><span class="samp">shr.imp</span></samp>&rsquo;,
    799  1.5  mrg  which
    800  1.7  mrg                     <ul>
    801  1.7  mrg    <li>refers to &lsquo;<samp><span class="samp">libNAME.so.V(shr.o)</span></samp>&rsquo; as the "SONAME", to be recorded
    802  1.5  mrg    in the <code>Loader Section</code> of subsequent binaries
    803  1.7  mrg    <li>indicates whether &lsquo;<samp><span class="samp">libNAME.so.V(shr.o)</span></samp>&rsquo; is 32 or 64 bit
    804  1.7  mrg    <li>lists all the public symbols exported by &lsquo;<samp><span class="samp">lib.so.V(shr.o)</span></samp>&rsquo;,
    805  1.7  mrg    eventually decorated with the <code>&lsquo;</code><samp><span class="samp">weak</span></samp><code>&rsquo; Keyword</code>
    806  1.7  mrg    <li>is necessary for shared linking against &lsquo;<samp><span class="samp">lib.so.V(shr.o)</span></samp>&rsquo;
    807  1.7  mrg    </ul>
    808  1.7  mrg                  </ul>
    809  1.7  mrg             A symbolic link using the &lsquo;<samp><span class="samp">libNAME.so</span></samp>&rsquo; filename scheme is created:
    810  1.7  mrg                <ul>
    811  1.7  mrg   <li>pointing to the &lsquo;<samp><span class="samp">libNAME.so.V</span></samp>&rsquo; <code>Shared Archive Library</code> file
    812  1.7  mrg   <li>to permit the <code>ld Command</code> to find &lsquo;<samp><span class="samp">lib.so.V(shr.imp)</span></samp>&rsquo; via
    813  1.7  mrg   the &lsquo;<samp><span class="samp">-lNAME</span></samp>&rsquo; argument (requires <code>Runtime Linking</code> to be enabled)
    814  1.7  mrg   <li>to permit dynamic loading of &lsquo;<samp><span class="samp">lib.so.V(shr.o)</span></samp>&rsquo; without the need
    815  1.7  mrg   to specify the version number via <code>dlopen("libNAME.so(shr.o)",
    816  1.5  mrg   RTLD_MEMBER)</code>
    817  1.7  mrg   </ul>
    818  1.7  mrg           </dl>
    819  1.5  mrg 
    820  1.7  mrg      <p>As long as static library creation is enabled, upon:
    821  1.7  mrg           <dl>
    822  1.7  mrg <dt><code>--with-aix-soname=svr4</code><dd> A <code>Static Archive Library</code> is created:
    823  1.7  mrg                <ul>
    824  1.7  mrg  <li>using the &lsquo;<samp><span class="samp">libNAME.a</span></samp>&rsquo; filename scheme
    825  1.7  mrg  <li>with all the <code>Static Object</code> files as archive members, which
    826  1.7  mrg                     <ul>
    827  1.7  mrg    <li>are used for static linking
    828  1.7  mrg   </ul>
    829  1.7  mrg                 </ul>
    830  1.7  mrg           </dl>
    831  1.5  mrg 
    832  1.7  mrg      <p>While the aix-soname=&lsquo;<samp><span class="samp">svr4</span></samp>&rsquo; option does not create <code>Shared Object</code>
    833  1.5  mrg files as members of unversioned <code>Archive Library</code> files any more, package
    834  1.5  mrg managers still are responsible to
    835  1.5  mrg <a href="./specific.html#TransferAixShobj">transfer</a> <code>Shared Object</code> files
    836  1.5  mrg found as member of a previously installed unversioned <code>Archive Library</code>
    837  1.5  mrg file into the newly installed <code>Archive Library</code> file with the same
    838  1.5  mrg filename.
    839  1.7  mrg 
    840  1.7  mrg      <p><em>WARNING:</em> Creating <code>Shared Object</code> files with <code>Runtime Linking</code>
    841  1.5  mrg enabled may bloat the TOC, eventually leading to <code>TOC overflow</code> errors,
    842  1.7  mrg requiring the use of either the <samp><span class="option">-Wl,-bbigtoc</span></samp> linker flag (seen to
    843  1.5  mrg break with the <code>GDB</code> debugger) or some of the TOC-related compiler flags,
    844  1.5  mrg see &ldquo;RS/6000 and PowerPC Options&rdquo; in the main manual.
    845  1.7  mrg 
    846  1.7  mrg      <p><samp><span class="option">--with-aix-soname</span></samp> is currently supported by &lsquo;<samp><span class="samp">libgcc_s</span></samp>&rsquo; only, so
    847  1.5  mrg this option is still experimental and not for normal use yet.
    848  1.7  mrg 
    849  1.7  mrg      <p>Default is the traditional behavior <samp><span class="option">--with-aix-soname=&lsquo;</span><samp><span class="samp">aix</span></samp><span class="option">&rsquo;</span></samp>.
    850  1.7  mrg 
    851  1.7  mrg      <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
    852  1.1  mrg their runtime libraries should be built.  For a list of valid values for
    853  1.1  mrg <var>langN</var> you can issue the following command in the
    854  1.7  mrg <samp><span class="file">gcc</span></samp> directory of your GCC source tree:<br>
    855  1.7  mrg      <pre class="smallexample">          grep ^language= */config-lang.in
    856  1.7  mrg </pre>
    857  1.7  mrg      <p>Currently, you can use any of the following:
    858  1.3  mrg <code>all</code>, <code>ada</code>, <code>c</code>, <code>c++</code>, <code>fortran</code>,
    859  1.7  mrg <code>go</code>, <code>java</code>, <code>jit</code>, <code>lto</code>, <code>objc</code>, <code>obj-c++</code>. 
    860  1.7  mrg Building the Ada compiler has special requirements, see below. 
    861  1.1  mrg If you do not pass this flag, or specify the option <code>all</code>, then all
    862  1.7  mrg default languages available in the <samp><span class="file">gcc</span></samp> sub-tree will be configured. 
    863  1.7  mrg Ada, Go, Jit, and Objective-C++ are not default languages.  LTO is not a
    864  1.7  mrg default language, but is built by default because <samp><span class="option">--enable-lto</span></samp> is
    865  1.7  mrg enabled by default.  The other languages are default languages.
    866  1.7  mrg 
    867  1.7  mrg      <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
    868  1.1  mrg libraries should be built with the system C compiler during stage 1 of
    869  1.1  mrg the bootstrap process, rather than only in later stages with the
    870  1.1  mrg bootstrapped C compiler.  The list of valid values is the same as for
    871  1.7  mrg <samp><span class="option">--enable-languages</span></samp>, and the option <code>all</code> will select all
    872  1.7  mrg of the languages enabled by <samp><span class="option">--enable-languages</span></samp>.  This option is
    873  1.1  mrg primarily useful for GCC development; for instance, when a development
    874  1.1  mrg version of the compiler cannot bootstrap due to compiler bugs, or when
    875  1.1  mrg one is debugging front ends other than the C front end.  When this
    876  1.1  mrg option is used, one can then build the target libraries for the
    877  1.7  mrg specified languages with the stage-1 compiler by using <samp><span class="command">make
    878  1.7  mrg stage1-bubble all-target</span></samp>, or run the testsuite on the stage-1 compiler
    879  1.7  mrg for the specified languages using <samp><span class="command">make stage1-start check-gcc</span></samp>.
    880  1.7  mrg 
    881  1.7  mrg      <br><dt><code>--disable-libada</code><dd>Specify that the run-time libraries and tools used by GNAT should not
    882  1.1  mrg be built.  This can be useful for debugging, or for compatibility with
    883  1.1  mrg previous Ada build procedures, when it was required to explicitly
    884  1.7  mrg do a &lsquo;<samp><span class="samp">make -C gcc gnatlib_and_tools</span></samp>&rsquo;.
    885  1.7  mrg 
    886  1.7  mrg      <br><dt><code>--disable-libsanitizer</code><dd>Specify that the run-time libraries for the various sanitizers should
    887  1.5  mrg not be built.
    888  1.7  mrg 
    889  1.7  mrg      <br><dt><code>--disable-libssp</code><dd>Specify that the run-time libraries for stack smashing protection
    890  1.1  mrg should not be built.
    891  1.7  mrg 
    892  1.7  mrg      <br><dt><code>--disable-libquadmath</code><dd>Specify that the GCC quad-precision math library should not be built. 
    893  1.3  mrg On some systems, the library is required to be linkable when building
    894  1.7  mrg the Fortran front end, unless <samp><span class="option">--disable-libquadmath-support</span></samp>
    895  1.3  mrg is used.
    896  1.7  mrg 
    897  1.7  mrg      <br><dt><code>--disable-libquadmath-support</code><dd>Specify that the Fortran front end and <code>libgfortran</code> do not add
    898  1.3  mrg support for <code>libquadmath</code> on systems supporting it.
    899  1.7  mrg 
    900  1.7  mrg      <br><dt><code>--disable-libgomp</code><dd>Specify that the GNU Offloading and Multi Processing Runtime Library
    901  1.5  mrg should not be built.
    902  1.7  mrg 
    903  1.7  mrg      <br><dt><code>--disable-libvtv</code><dd>Specify that the run-time libraries used by vtable verification
    904  1.5  mrg should not be built.
    905  1.7  mrg 
    906  1.7  mrg      <br><dt><code>--with-dwarf2</code><dd>Specify that the compiler should
    907  1.1  mrg use DWARF 2 debugging information as the default.
    908  1.7  mrg 
    909  1.7  mrg      <br><dt><code>--with-advance-toolchain=</code><var>at</var><dd>On 64-bit PowerPC Linux systems, configure the compiler to use the
    910  1.7  mrg header files, library files, and the dynamic linker from the Advance
    911  1.7  mrg Toolchain release <var>at</var> instead of the default versions that are
    912  1.7  mrg provided by the Linux distribution.  In general, this option is
    913  1.7  mrg intended for the developers of GCC, and it is not intended for general
    914  1.7  mrg use.
    915  1.7  mrg 
    916  1.7  mrg      <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. 
    917  1.1  mrg These are compilers that are able to generate either 64-bit or 32-bit
    918  1.7  mrg code.  Typically, the corresponding 32-bit target, e.g. 
    919  1.1  mrg powerpc-linux for powerpc64-linux, only generates 32-bit code.  This
    920  1.1  mrg option enables the 32-bit target to be a bi-arch compiler, which is
    921  1.1  mrg useful when you want a bi-arch compiler that defaults to 32-bit, and
    922  1.7  mrg you are building a bi-arch or multi-arch binutils in a combined tree. 
    923  1.1  mrg On mips-linux, this will build a tri-arch compiler (ABI o32/n32/64),
    924  1.7  mrg defaulted to o32. 
    925  1.3  mrg Currently, this option only affects sparc-linux, powerpc-linux, x86-linux,
    926  1.3  mrg mips-linux and s390-linux.
    927  1.7  mrg 
    928  1.7  mrg      <br><dt><code>--enable-default-pie</code><dd>Turn on <samp><span class="option">-fPIE</span></samp> and <samp><span class="option">-pie</span></samp> by default.
    929  1.7  mrg 
    930  1.7  mrg      <br><dt><code>--enable-secureplt</code><dd>This option enables <samp><span class="option">-msecure-plt</span></samp> by default for powerpc-linux. 
    931  1.1  mrg See &ldquo;RS/6000 and PowerPC Options&rdquo; in the main manual
    932  1.7  mrg 
    933  1.7  mrg      <br><dt><code>--enable-default-ssp</code><dd>Turn on <samp><span class="option">-fstack-protector-strong</span></samp> by default.
    934  1.7  mrg 
    935  1.7  mrg      <br><dt><code>--enable-cld</code><dd>This option enables <samp><span class="option">-mcld</span></samp> by default for 32-bit x86 targets. 
    936  1.1  mrg See &ldquo;i386 and x86-64 Options&rdquo; in the main manual
    937  1.7  mrg 
    938  1.7  mrg      <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
    939  1.1  mrg to look up installations paths in the registry using the following key:
    940  1.1  mrg 
    941  1.7  mrg      <pre class="smallexample">          <code>HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\</code><var>key</var>
    942  1.7  mrg </pre>
    943  1.7  mrg      <p><var>key</var> defaults to GCC version number, and can be overridden by the
    944  1.7  mrg <samp><span class="option">--enable-win32-registry=</span><var>key</var></samp> option.  Vendors and distributors
    945  1.1  mrg who use custom installers are encouraged to provide a different key,
    946  1.1  mrg perhaps one comprised of vendor name and GCC version number, to
    947  1.1  mrg avoid conflict with existing installations.  This feature is enabled
    948  1.7  mrg by default, and can be disabled by <samp><span class="option">--disable-win32-registry</span></samp>
    949  1.1  mrg option.  This option has no effect on the other hosts.
    950  1.7  mrg 
    951  1.7  mrg      <br><dt><code>--nfp</code><dd>Specify that the machine does not have a floating point unit.  This
    952  1.7  mrg option only applies to &lsquo;<samp><span class="samp">m68k-sun-sunos</span><var>n</var></samp>&rsquo;.  On any other
    953  1.7  mrg system, <samp><span class="option">--nfp</span></samp> has no effect.
    954  1.7  mrg 
    955  1.7  mrg      <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
    956  1.7  mrg compiler are built with <samp><span class="option">-Werror</span></samp> in bootstrap stage2 and later. 
    957  1.7  mrg If you don't specify it, <samp><span class="option">-Werror</span></samp> is turned on for the main
    958  1.1  mrg development trunk.  However it defaults to off for release branches and
    959  1.7  mrg final releases.  The specific files which get <samp><span class="option">-Werror</span></samp> are
    960  1.1  mrg controlled by the Makefiles.
    961  1.7  mrg 
    962  1.7  mrg      <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
    963  1.1  mrg consistency checks of the requested complexity.  This does not change the
    964  1.1  mrg generated code, but adds error checking within the compiler.  This will
    965  1.1  mrg slow down the compiler and may only work properly if you are building
    966  1.7  mrg the compiler with GCC.  This is &lsquo;<samp><span class="samp">yes</span></samp>&rsquo; by default when building
    967  1.7  mrg from SVN or snapshots, but &lsquo;<samp><span class="samp">release</span></samp>&rsquo; for releases.  The default
    968  1.7  mrg for building the stage1 compiler is &lsquo;<samp><span class="samp">yes</span></samp>&rsquo;.  More control
    969  1.1  mrg over the checks may be had by specifying <var>list</var>.  The categories of
    970  1.7  mrg checks available are &lsquo;<samp><span class="samp">yes</span></samp>&rsquo; (most common checks
    971  1.7  mrg &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
    972  1.7  mrg all), &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
    973  1.7  mrg checks &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;). 
    974  1.7  mrg Individual checks can be enabled with these flags &lsquo;<samp><span class="samp">assert</span></samp>&rsquo;,
    975  1.7  mrg &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;,
    976  1.7  mrg &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;.
    977  1.7  mrg 
    978  1.7  mrg      <p>The &lsquo;<samp><span class="samp">valgrind</span></samp>&rsquo; check requires the external <samp><span class="command">valgrind</span></samp>
    979  1.1  mrg simulator, available from <a href="http://valgrind.org/">http://valgrind.org/</a>.  The
    980  1.7  mrg &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. 
    981  1.7  mrg To disable all checking, &lsquo;<samp><span class="samp">--disable-checking</span></samp>&rsquo; or
    982  1.7  mrg &lsquo;<samp><span class="samp">--enable-checking=none</span></samp>&rsquo; must be explicitly requested.  Disabling
    983  1.1  mrg assertions will make the compiler and runtime slightly faster but
    984  1.1  mrg increase the risk of undetected internal errors causing wrong code to be
    985  1.1  mrg generated.
    986  1.7  mrg 
    987  1.7  mrg      <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
    988  1.7  mrg compiler will be built with &lsquo;<samp><span class="samp">yes</span></samp>&rsquo; checking enabled, otherwise
    989  1.1  mrg the stage1 checking flags are the same as specified by
    990  1.7  mrg <samp><span class="option">--enable-checking</span></samp>.  To build the stage1 compiler with
    991  1.7  mrg different checking options use <samp><span class="option">--enable-stage1-checking</span></samp>. 
    992  1.7  mrg The list of checking options is the same as for <samp><span class="option">--enable-checking</span></samp>. 
    993  1.1  mrg If your system is too slow or too small to bootstrap a released compiler
    994  1.7  mrg with checking for stage1 enabled, you can use &lsquo;<samp><span class="samp">--disable-stage1-checking</span></samp>&rsquo;
    995  1.1  mrg to disable checking for the stage1 compiler.
    996  1.7  mrg 
    997  1.7  mrg      <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
    998  1.1  mrg information, every time it is run.  This is for internal development
    999  1.1  mrg purposes, and only works when the compiler is being built with gcc.  The
   1000  1.1  mrg <var>level</var> argument controls whether the compiler is built optimized or
   1001  1.7  mrg not, 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
   1002  1.1  mrg want to disable optimization, for performance analysis you want to
   1003  1.1  mrg enable optimization.  When coverage is enabled, the default level is
   1004  1.1  mrg without optimization.
   1005  1.7  mrg 
   1006  1.7  mrg      <br><dt><code>--enable-gather-detailed-mem-stats</code><dd>When this option is specified more detailed information on memory
   1007  1.1  mrg allocation is gathered.  This information is printed when using
   1008  1.7  mrg <samp><span class="option">-fmem-report</span></samp>.
   1009  1.7  mrg 
   1010  1.7  mrg      <br><dt><code>--enable-valgrind-annotations</code><dd>Mark selected memory related operations in the compiler when run under
   1011  1.7  mrg valgrind to suppress false positives.
   1012  1.7  mrg 
   1013  1.7  mrg      <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),
   1014  1.1  mrg which lets GCC output diagnostics in languages other than American
   1015  1.1  mrg English.  Native Language Support is enabled by default if not doing a
   1016  1.7  mrg canadian cross build.  The <samp><span class="option">--disable-nls</span></samp> option disables NLS.
   1017  1.7  mrg 
   1018  1.7  mrg      <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
   1019  1.7  mrg procedure to prefer its copy of GNU <samp><span class="command">gettext</span></samp>.
   1020  1.7  mrg 
   1021  1.7  mrg      <br><dt><code>--with-catgets</code><dd>If NLS is enabled, and if the host lacks <code>gettext</code> but has the
   1022  1.1  mrg inferior <code>catgets</code> interface, the GCC build procedure normally
   1023  1.7  mrg ignores <code>catgets</code> and instead uses GCC's copy of the GNU
   1024  1.7  mrg <code>gettext</code> library.  The <samp><span class="option">--with-catgets</span></samp> option causes the
   1025  1.7  mrg build procedure to use the host's <code>catgets</code> in this situation.
   1026  1.7  mrg 
   1027  1.7  mrg      <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
   1028  1.7  mrg libiconv library files in <samp><var>dir</var><span class="file">/lib</span></samp>.
   1029  1.7  mrg 
   1030  1.7  mrg      <br><dt><code>--enable-obsolete</code><dd>Enable configuration for an obsoleted system.  If you attempt to
   1031  1.1  mrg configure GCC for a system (build, host, or target) which has been
   1032  1.1  mrg obsoleted, and you do not specify this flag, configure will halt with an
   1033  1.1  mrg error message.
   1034  1.7  mrg 
   1035  1.7  mrg      <p>All support for systems which have been obsoleted in one release of GCC
   1036  1.1  mrg is removed entirely in the next major release, unless someone steps
   1037  1.1  mrg forward to maintain the port.
   1038  1.7  mrg 
   1039  1.7  mrg      <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
   1040  1.1  mrg that is in the IEEE 754-2008 standard.  This is enabled by default only
   1041  1.1  mrg on PowerPC, i386, and x86_64 GNU/Linux systems.  Other systems may also
   1042  1.1  mrg support it, but require the user to specifically enable it.  You can
   1043  1.1  mrg optionally control which decimal floating point format is used (either
   1044  1.7  mrg &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)
   1045  1.7  mrg format is default on i386 and x86_64 systems, and the &lsquo;<samp><span class="samp">dpd</span></samp>&rsquo;
   1046  1.1  mrg (densely packed decimal) format is default on PowerPC systems.
   1047  1.7  mrg 
   1048  1.7  mrg      <br><dt><code>--enable-fixed-point</code><dt><code>--disable-fixed-point</code><dd>Enable (or disable) support for C fixed-point arithmetic. 
   1049  1.1  mrg This option is enabled by default for some targets (such as MIPS) which
   1050  1.1  mrg have hardware-support for fixed-point operations.  On other targets, you
   1051  1.1  mrg may enable this option manually.
   1052  1.7  mrg 
   1053  1.7  mrg      <br><dt><code>--with-long-double-128</code><dd>Specify if <code>long double</code> type should be 128-bit by default on selected
   1054  1.1  mrg GNU/Linux architectures.  If using <code>--without-long-double-128</code>,
   1055  1.7  mrg <code>long double</code> will be by default 64-bit, the same as <code>double</code> type. 
   1056  1.1  mrg When neither of these configure options are used, the default will be
   1057  1.1  mrg 128-bit <code>long double</code> when built against GNU C Library 2.4 and later,
   1058  1.1  mrg 64-bit <code>long double</code> otherwise.
   1059  1.7  mrg 
   1060  1.7  mrg      <br><dt><code>--enable-fdpic</code><dd>On SH Linux systems, generate ELF FDPIC code.
   1061  1.7  mrg 
   1062  1.7  mrg      <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 want to build GCC but do not have the GMP library, the MPFR
   1063  1.1  mrg library and/or the MPC library installed in a standard location and
   1064  1.3  mrg do not have their sources present in the GCC source tree then you
   1065  1.3  mrg can explicitly specify the directory where they are installed
   1066  1.7  mrg (&lsquo;<samp><span class="samp">--with-gmp=</span><var>gmpinstalldir</var></samp>&rsquo;,
   1067  1.7  mrg &lsquo;<samp><span class="samp">--with-mpfr=</span><var>mpfrinstalldir</var></samp>&rsquo;,
   1068  1.7  mrg &lsquo;<samp><span class="samp">--with-mpc=</span><var>mpcinstalldir</var></samp>&rsquo;).  The
   1069  1.7  mrg <samp><span class="option">--with-gmp=</span><var>gmpinstalldir</var></samp> option is shorthand for
   1070  1.7  mrg <samp><span class="option">--with-gmp-lib=</span><var>gmpinstalldir</var><span class="option">/lib</span></samp> and
   1071  1.7  mrg <samp><span class="option">--with-gmp-include=</span><var>gmpinstalldir</var><span class="option">/include</span></samp>.  Likewise the
   1072  1.7  mrg <samp><span class="option">--with-mpfr=</span><var>mpfrinstalldir</var></samp> option is shorthand for
   1073  1.7  mrg <samp><span class="option">--with-mpfr-lib=</span><var>mpfrinstalldir</var><span class="option">/lib</span></samp> and
   1074  1.7  mrg <samp><span class="option">--with-mpfr-include=</span><var>mpfrinstalldir</var><span class="option">/include</span></samp>, also the
   1075  1.7  mrg <samp><span class="option">--with-mpc=</span><var>mpcinstalldir</var></samp> option is shorthand for
   1076  1.7  mrg <samp><span class="option">--with-mpc-lib=</span><var>mpcinstalldir</var><span class="option">/lib</span></samp> and
   1077  1.7  mrg <samp><span class="option">--with-mpc-include=</span><var>mpcinstalldir</var><span class="option">/include</span></samp>.  If these
   1078  1.1  mrg shorthand assumptions are not correct, you can use the explicit
   1079  1.3  mrg include and lib options directly.  You might also need to ensure the
   1080  1.3  mrg shared libraries can be found by the dynamic linker when building and
   1081  1.3  mrg using GCC, for example by setting the runtime shared library path
   1082  1.7  mrg variable (<samp><span class="env">LD_LIBRARY_PATH</span></samp> on GNU/Linux and Solaris systems).
   1083  1.7  mrg 
   1084  1.7  mrg      <p>These flags are applicable to the host platform only.  When building
   1085  1.3  mrg a cross compiler, they will not be used to configure target libraries.
   1086  1.7  mrg 
   1087  1.7  mrg      <br><dt><code>--with-isl=</code><var>pathname</var><dt><code>--with-isl-include=</code><var>pathname</var><dt><code>--with-isl-lib=</code><var>pathname</var><dd>If you do not have the isl library installed in a standard location and you
   1088  1.5  mrg want to build GCC, you can explicitly specify the directory where it is
   1089  1.7  mrg installed (&lsquo;<samp><span class="samp">--with-isl=</span><var>islinstalldir</var></samp>&rsquo;). The
   1090  1.7  mrg <samp><span class="option">--with-isl=</span><var>islinstalldir</var></samp> option is shorthand for
   1091  1.7  mrg <samp><span class="option">--with-isl-lib=</span><var>islinstalldir</var><span class="option">/lib</span></samp> and
   1092  1.7  mrg <samp><span class="option">--with-isl-include=</span><var>islinstalldir</var><span class="option">/include</span></samp>. If this
   1093  1.5  mrg shorthand assumption is not correct, you can use the explicit
   1094  1.1  mrg include and lib options directly.
   1095  1.7  mrg 
   1096  1.7  mrg      <p>These flags are applicable to the host platform only.  When building
   1097  1.3  mrg a cross compiler, they will not be used to configure target libraries.
   1098  1.7  mrg 
   1099  1.7  mrg      <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
   1100  1.1  mrg stage 1 of GCC.  These are also used when linking GCC if configured with
   1101  1.7  mrg <samp><span class="option">--disable-bootstrap</span></samp>.  If <samp><span class="option">--with-stage1-libs</span></samp> is not set to a
   1102  1.7  mrg value, then the default is &lsquo;<samp><span class="samp">-static-libstdc++ -static-libgcc</span></samp>&rsquo;, if
   1103  1.7  mrg supported.
   1104  1.7  mrg 
   1105  1.7  mrg      <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
   1106  1.1  mrg of GCC.  These are also used when linking GCC if configured with
   1107  1.7  mrg <samp><span class="option">--disable-bootstrap</span></samp>.
   1108  1.7  mrg 
   1109  1.7  mrg      <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
   1110  1.7  mrg stage 2 and later when bootstrapping GCC.  If &ndash;with-boot-libs
   1111  1.7  mrg is not is set to a value, then the default is
   1112  1.7  mrg &lsquo;<samp><span class="samp">-static-libstdc++ -static-libgcc</span></samp>&rsquo;.
   1113  1.7  mrg 
   1114  1.7  mrg      <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
   1115  1.7  mrg and later when bootstrapping GCC.
   1116  1.7  mrg 
   1117  1.7  mrg      <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
   1118  1.1  mrg building runtime libraries.  &lsquo;<samp><var>map</var></samp>&rsquo; is a space-separated
   1119  1.7  mrg list of maps of the form &lsquo;<samp><var>old</var><span class="samp">=</span><var>new</var></samp>&rsquo;.
   1120  1.7  mrg 
   1121  1.7  mrg      <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
   1122  1.7  mrg links (links performed without the <samp><span class="option">-r</span></samp> or <samp><span class="option">--relocatable</span></samp>
   1123  1.1  mrg option), if the linker supports it.  If you specify
   1124  1.7  mrg <samp><span class="option">--enable-linker-build-id</span></samp>, but your linker does not
   1125  1.7  mrg support <samp><span class="option">--build-id</span></samp> option, a warning is issued and the
   1126  1.7  mrg <samp><span class="option">--enable-linker-build-id</span></samp> option is ignored.  The default is off.
   1127  1.7  mrg 
   1128  1.7  mrg      <br><dt><code>--with-linker-hash-style=</code><var>choice</var><dd>Tells GCC to pass <samp><span class="option">--hash-style=</span><var>choice</var></samp> option to the
   1129  1.3  mrg linker for all final links. <var>choice</var> can be one of
   1130  1.7  mrg &lsquo;<samp><span class="samp">sysv</span></samp>&rsquo;, &lsquo;<samp><span class="samp">gnu</span></samp>&rsquo;, and &lsquo;<samp><span class="samp">both</span></samp>&rsquo; where &lsquo;<samp><span class="samp">sysv</span></samp>&rsquo; is the default.
   1131  1.7  mrg 
   1132  1.7  mrg      <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
   1133  1.1  mrg static data members and inline function local statics.  Enabled by
   1134  1.5  mrg default for a toolchain with an assembler that accepts it and
   1135  1.1  mrg GLIBC 2.11 or above, otherwise disabled.
   1136  1.7  mrg 
   1137  1.7  mrg      <br><dt><code>--with-diagnostics-color=</code><var>choice</var><dd>Tells GCC to use <var>choice</var> as the default for <samp><span class="option">-fdiagnostics-color=</span></samp>
   1138  1.5  mrg option (if not used explicitly on the command line).  <var>choice</var>
   1139  1.7  mrg can be one of &lsquo;<samp><span class="samp">never</span></samp>&rsquo;, &lsquo;<samp><span class="samp">auto</span></samp>&rsquo;, &lsquo;<samp><span class="samp">always</span></samp>&rsquo;, and &lsquo;<samp><span class="samp">auto-if-env</span></samp>&rsquo;
   1140  1.7  mrg where &lsquo;<samp><span class="samp">auto</span></samp>&rsquo; is the default.  &lsquo;<samp><span class="samp">auto-if-env</span></samp>&rsquo; means that
   1141  1.7  mrg <samp><span class="option">-fdiagnostics-color=auto</span></samp> will be the default if <code>GCC_COLORS</code>
   1142  1.5  mrg is present and non-empty in the environment, and
   1143  1.7  mrg <samp><span class="option">-fdiagnostics-color=never</span></samp> otherwise.
   1144  1.7  mrg 
   1145  1.7  mrg      <br><dt><code>--enable-lto</code><dt><code>--disable-lto</code><dd>Enable support for link-time optimization (LTO).  This is enabled by
   1146  1.7  mrg default, and may be disabled using <samp><span class="option">--disable-lto</span></samp>.
   1147  1.7  mrg 
   1148  1.7  mrg      <br><dt><code>--enable-linker-plugin-configure-flags=FLAGS</code><dt><code>--enable-linker-plugin-flags=FLAGS</code><dd>By default, linker plugins (such as the LTO plugin) are built for the
   1149  1.5  mrg host system architecture.  For the case that the linker has a
   1150  1.5  mrg different (but run-time compatible) architecture, these flags can be
   1151  1.5  mrg specified to build plugins that are compatible to the linker.  For
   1152  1.5  mrg example, if you are building GCC for a 64-bit x86_64
   1153  1.7  mrg (&lsquo;<samp><span class="samp">x86_64-unknown-linux-gnu</span></samp>&rsquo;) host system, but have a 32-bit x86
   1154  1.7  mrg GNU/Linux (&lsquo;<samp><span class="samp">i686-pc-linux-gnu</span></samp>&rsquo;) linker executable (which is
   1155  1.5  mrg executable on the former system), you can configure GCC as follows for
   1156  1.5  mrg getting compatible linker plugins:
   1157  1.7  mrg 
   1158  1.7  mrg      <pre class="smallexample">          % <var>srcdir</var>/configure \
   1159  1.7  mrg               --host=x86_64-unknown-linux-gnu \
   1160  1.7  mrg               --enable-linker-plugin-configure-flags=--host=i686-pc-linux-gnu \
   1161  1.7  mrg               --enable-linker-plugin-flags='CC=gcc\ -m32\ -Wl,-rpath,[...]/i686-pc-linux-gnu/lib'
   1162  1.7  mrg </pre>
   1163  1.7  mrg      <br><dt><code>--with-plugin-ld=</code><var>pathname</var><dd>Enable an alternate linker to be used at link-time optimization (LTO)
   1164  1.7  mrg link time when <samp><span class="option">-fuse-linker-plugin</span></samp> is enabled. 
   1165  1.3  mrg This linker should have plugin support such as gold starting with
   1166  1.7  mrg version 2.20 or GNU ld starting with version 2.21. 
   1167  1.7  mrg See <samp><span class="option">-fuse-linker-plugin</span></samp> for details.
   1168  1.7  mrg 
   1169  1.7  mrg      <br><dt><code>--enable-canonical-system-headers</code><dt><code>--disable-canonical-system-headers</code><dd>Enable system header path canonicalization for <samp><span class="file">libcpp</span></samp>.  This can
   1170  1.3  mrg produce shorter header file paths in diagnostics and dependency output
   1171  1.3  mrg files, but these changed header paths may conflict with some compilation
   1172  1.3  mrg environments.  Enabled by default, and may be disabled using
   1173  1.7  mrg <samp><span class="option">--disable-canonical-system-headers</span></samp>.
   1174  1.7  mrg 
   1175  1.7  mrg      <br><dt><code>--with-glibc-version=</code><var>major</var><code>.</code><var>minor</var><dd>Tell GCC that when the GNU C Library (glibc) is used on the target it
   1176  1.5  mrg will be version <var>major</var>.<var>minor</var> or later.  Normally this can
   1177  1.7  mrg be detected from the C library's header files, but this option may be
   1178  1.5  mrg needed when bootstrapping a cross toolchain without the header files
   1179  1.5  mrg available for building the initial bootstrap compiler.
   1180  1.7  mrg 
   1181  1.7  mrg      <p>If GCC is configured with some multilibs that use glibc and some that
   1182  1.7  mrg do not, this option applies only to the multilibs that use glibc. 
   1183  1.5  mrg However, such configurations may not work well as not all the relevant
   1184  1.5  mrg configuration in GCC is on a per-multilib basis.
   1185  1.7  mrg 
   1186  1.7  mrg      <br><dt><code>--enable-as-accelerator-for=</code><var>target</var><dd>Build as offload target compiler. Specify offload host triple by <var>target</var>.
   1187  1.7  mrg 
   1188  1.7  mrg      <br><dt><code>--enable-offload-targets=</code><var>target1</var><code>[=</code><var>path1</var><code>],...,</code><var>targetN</var><code>[=</code><var>pathN</var><code>]</code><dd>Enable offloading to targets <var>target1</var>, <small class="dots">...</small>, <var>targetN</var>. 
   1189  1.5  mrg Offload compilers are expected to be already installed.  Default search
   1190  1.5  mrg path for them is <samp><var>exec-prefix</var></samp>, but it can be changed by
   1191  1.7  mrg specifying paths <var>path1</var>, <small class="dots">...</small>, <var>pathN</var>.
   1192  1.7  mrg 
   1193  1.7  mrg      <pre class="smallexample">          % <var>srcdir</var>/configure \
   1194  1.7  mrg               --enable-offload-target=i686-unknown-linux-gnu=/path/to/i686/compiler,x86_64-pc-linux-gnu
   1195  1.7  mrg </pre>
   1196  1.7  mrg      <p>If &lsquo;<samp><span class="samp">hsa</span></samp>&rsquo; is specified as one of the targets, the compiler will be
   1197  1.7  mrg built with support for HSA GPU accelerators.  Because the same
   1198  1.7  mrg compiler will emit the accelerator code, no path should be specified.
   1199  1.7  mrg 
   1200  1.7  mrg      <br><dt><code>--with-hsa-runtime=</code><var>pathname</var><dt><code>--with-hsa-runtime-include=</code><var>pathname</var><dt><code>--with-hsa-runtime-lib=</code><var>pathname</var><dd>
   1201  1.7  mrg If you configure GCC with HSA offloading but do not have the HSA
   1202  1.7  mrg run-time library installed in a standard location then you can
   1203  1.7  mrg explicitly specify the directory where they are installed.  The
   1204  1.7  mrg <samp><span class="option">--with-hsa-runtime=</span><var>hsainstalldir</var></samp> option is a
   1205  1.7  mrg shorthand for
   1206  1.7  mrg <samp><span class="option">--with-hsa-runtime-lib=</span><var>hsainstalldir</var><span class="option">/lib</span></samp> and
   1207  1.7  mrg <samp><span class="option">--with-hsa-runtime-include=</span><var>hsainstalldir</var><span class="option">/include</span></samp>.
   1208  1.7  mrg 
   1209  1.7  mrg      <br><dt><code>--with-hsa-kmt-lib=</code><var>pathname</var><dd>
   1210  1.7  mrg If you configure GCC with HSA offloading but do not have the HSA
   1211  1.7  mrg KMT library installed in a standard location then you can
   1212  1.7  mrg explicitly specify the directory where it resides. 
   1213  1.6  mrg </dl>
   1214  1.1  mrg 
   1215  1.7  mrg <h4 class="subheading"><a name="TOC3"></a>Cross-Compiler-Specific Options</h4>
   1216  1.7  mrg 
   1217  1.1  mrg <p>The following options only apply to building cross compilers.
   1218  1.7  mrg 
   1219  1.7  mrg      <dl>
   1220  1.7  mrg <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
   1221  1.7  mrg (a subset of) the root filesystem of the target operating system. 
   1222  1.1  mrg Target system headers, libraries and run-time object files will be
   1223  1.3  mrg searched for in there.  More specifically, this acts as if
   1224  1.7  mrg <samp><span class="option">--sysroot=</span><var>dir</var></samp> was added to the default options of the built
   1225  1.1  mrg compiler.  The specified directory is not copied into the
   1226  1.7  mrg install tree, unlike the options <samp><span class="option">--with-headers</span></samp> and
   1227  1.7  mrg <samp><span class="option">--with-libs</span></samp> that this option obsoletes.  The default value,
   1228  1.7  mrg in case <samp><span class="option">--with-sysroot</span></samp> is not given an argument, is
   1229  1.7  mrg <samp><span class="option">${gcc_tooldir}/sys-root</span></samp>.  If the specified directory is a
   1230  1.7  mrg subdirectory of <samp><span class="option">${exec_prefix}</span></samp>, then it will be found relative to
   1231  1.1  mrg the GCC binaries if the installation tree is moved.
   1232  1.7  mrg 
   1233  1.7  mrg      <p>This option affects the system root for the compiler used to build
   1234  1.1  mrg target libraries (which runs on the build system) and the compiler newly
   1235  1.1  mrg installed with <code>make install</code>; it does not affect the compiler which is
   1236  1.1  mrg used to build GCC itself.
   1237  1.7  mrg 
   1238  1.7  mrg      <p>If you specify the <samp><span class="option">--with-native-system-header-dir=</span><var>dirname</var></samp>
   1239  1.3  mrg option then the compiler will search that directory within <var>dirname</var> for
   1240  1.7  mrg native system headers rather than the default <samp><span class="file">/usr/include</span></samp>.
   1241  1.7  mrg 
   1242  1.7  mrg      <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
   1243  1.7  mrg <samp><span class="option">--with-sysroot</span></samp>) while building target libraries, instead of
   1244  1.7  mrg the directory specified with <samp><span class="option">--with-sysroot</span></samp>.  This option is
   1245  1.7  mrg only useful when you are already using <samp><span class="option">--with-sysroot</span></samp>.  You
   1246  1.7  mrg can use <samp><span class="option">--with-build-sysroot</span></samp> when you are configuring with
   1247  1.7  mrg <samp><span class="option">--prefix</span></samp> set to a directory that is different from the one in
   1248  1.1  mrg which you are installing GCC and your target libraries.
   1249  1.7  mrg 
   1250  1.7  mrg      <p>This option affects the system root for the compiler used to build
   1251  1.1  mrg target libraries (which runs on the build system); it does not affect
   1252  1.1  mrg the compiler which is used to build GCC itself.
   1253  1.7  mrg 
   1254  1.7  mrg      <p>If you specify the <samp><span class="option">--with-native-system-header-dir=</span><var>dirname</var></samp>
   1255  1.3  mrg option then the compiler will search that directory within <var>dirname</var> for
   1256  1.7  mrg native system headers rather than the default <samp><span class="file">/usr/include</span></samp>.
   1257  1.7  mrg 
   1258  1.7  mrg      <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>. 
   1259  1.7  mrg Specifies that target headers are available when building a cross compiler. 
   1260  1.1  mrg The <var>dir</var> argument specifies a directory which has the target include
   1261  1.7  mrg files.  These include files will be copied into the <samp><span class="file">gcc</span></samp> install
   1262  1.7  mrg directory.  <em>This option with the </em><var>dir</var><em> argument is required</em> when
   1263  1.7  mrg building a cross compiler, if <samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/sys-include</span></samp>
   1264  1.7  mrg doesn't pre-exist.  If <samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/sys-include</span></samp> does
   1265  1.7  mrg pre-exist, the <var>dir</var> argument may be omitted.  <samp><span class="command">fixincludes</span></samp>
   1266  1.1  mrg will be run on these files to make them compatible with GCC.
   1267  1.7  mrg 
   1268  1.7  mrg      <br><dt><code>--without-headers</code><dd>Tells GCC not use any target headers from a libc when building a cross
   1269  1.1  mrg compiler.  When crossing to GNU/Linux, you need the headers so GCC
   1270  1.1  mrg can build the exception handling for libgcc.
   1271  1.7  mrg 
   1272  1.7  mrg      <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>. 
   1273  1.1  mrg Specifies a list of directories which contain the target runtime
   1274  1.7  mrg libraries.  These libraries will be copied into the <samp><span class="file">gcc</span></samp> install
   1275  1.1  mrg directory.  If the directory list is omitted, this option has no
   1276  1.1  mrg effect.
   1277  1.7  mrg 
   1278  1.7  mrg      <br><dt><code>--with-newlib</code><dd>Specifies that &lsquo;<samp><span class="samp">newlib</span></samp>&rsquo; is
   1279  1.1  mrg being used as the target C library.  This causes <code>__eprintf</code> to be
   1280  1.7  mrg omitted from <samp><span class="file">libgcc.a</span></samp> on the assumption that it will be provided by
   1281  1.7  mrg &lsquo;<samp><span class="samp">newlib</span></samp>&rsquo;.
   1282  1.7  mrg 
   1283  1.7  mrg      <br><dt><code>--with-avrlibc</code><dd>Specifies that &lsquo;<samp><span class="samp">AVR-Libc</span></samp>&rsquo; is
   1284  1.3  mrg being used as the target C library.  This causes float support
   1285  1.7  mrg functions like <code>__addsf3</code> to be omitted from <samp><span class="file">libgcc.a</span></samp> on
   1286  1.7  mrg the assumption that it will be provided by <samp><span class="file">libm.a</span></samp>.  For more
   1287  1.7  mrg technical details, cf. <a href="http://gcc.gnu.org/PR54461">PR54461</a>. 
   1288  1.3  mrg This option is only supported for the AVR target.  It is not supported for
   1289  1.3  mrg RTEMS configurations, which currently use newlib.  The option is
   1290  1.3  mrg supported since version 4.7.2 and is the default in 4.8.0 and newer.
   1291  1.7  mrg 
   1292  1.7  mrg      <br><dt><code>--with-nds32-lib=</code><var>library</var><dd>Specifies that <var>library</var> setting is used for building <samp><span class="file">libgcc.a</span></samp>. 
   1293  1.7  mrg Currently, the valid <var>library</var> is &lsquo;<samp><span class="samp">newlib</span></samp>&rsquo; or &lsquo;<samp><span class="samp">mculib</span></samp>&rsquo;. 
   1294  1.5  mrg This option is only supported for the NDS32 target.
   1295  1.7  mrg 
   1296  1.7  mrg      <br><dt><code>--with-build-time-tools=</code><var>dir</var><dd>Specifies where to find the set of target tools (assembler, linker, etc.) 
   1297  1.1  mrg that will be used while building GCC itself.  This option can be useful
   1298  1.1  mrg if the directory layouts are different between the system you are building
   1299  1.1  mrg GCC on, and the system where you will deploy it.
   1300  1.7  mrg 
   1301  1.7  mrg      <p>For example, on an &lsquo;<samp><span class="samp">ia64-hp-hpux</span></samp>&rsquo; system, you may have the GNU
   1302  1.7  mrg assembler and linker in <samp><span class="file">/usr/bin</span></samp>, and the native tools in a
   1303  1.6  mrg different path, and build a toolchain that expects to find the
   1304  1.7  mrg native tools in <samp><span class="file">/usr/bin</span></samp>.
   1305  1.7  mrg 
   1306  1.7  mrg      <p>When you use this option, you should ensure that <var>dir</var> includes
   1307  1.7  mrg <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>,
   1308  1.7  mrg <samp><span class="command">ranlib</span></samp> and <samp><span class="command">strip</span></samp> if necessary, and possibly
   1309  1.7  mrg <samp><span class="command">objdump</span></samp>.  Otherwise, GCC may use an inconsistent set of
   1310  1.7  mrg tools. 
   1311  1.6  mrg </dl>
   1312  1.1  mrg 
   1313  1.7  mrg <h5 class="subsubheading"><a name="TOC4"></a>Overriding <samp><span class="command">configure</span></samp> test results</h5>
   1314  1.1  mrg 
   1315  1.6  mrg <p>Sometimes, it might be necessary to override the result of some
   1316  1.7  mrg <samp><span class="command">configure</span></samp> test, for example in order to ease porting to a new
   1317  1.7  mrg system or work around a bug in a test.  The toplevel <samp><span class="command">configure</span></samp>
   1318  1.6  mrg script provides three variables for this:
   1319  1.7  mrg 
   1320  1.7  mrg      <dl>
   1321  1.7  mrg <dt><code>build_configargs</code><dd><a name="index-g_t_0040code_007bbuild_005fconfigargs_007d-3"></a>The contents of this variable is passed to all build <samp><span class="command">configure</span></samp>
   1322  1.6  mrg scripts.
   1323  1.7  mrg 
   1324  1.7  mrg      <br><dt><code>host_configargs</code><dd><a name="index-g_t_0040code_007bhost_005fconfigargs_007d-4"></a>The contents of this variable is passed to all host <samp><span class="command">configure</span></samp>
   1325  1.6  mrg scripts.
   1326  1.7  mrg 
   1327  1.7  mrg      <br><dt><code>target_configargs</code><dd><a name="index-g_t_0040code_007btarget_005fconfigargs_007d-5"></a>The contents of this variable is passed to all target <samp><span class="command">configure</span></samp>
   1328  1.6  mrg scripts.
   1329  1.1  mrg 
   1330  1.7  mrg    </dl>
   1331  1.7  mrg 
   1332  1.7  mrg    <p>In order to avoid shell and <samp><span class="command">make</span></samp> quoting issues for complex
   1333  1.7  mrg overrides, you can pass a setting for <samp><span class="env">CONFIG_SITE</span></samp> and set
   1334  1.6  mrg variables in the site file.
   1335  1.7  mrg 
   1336  1.7  mrg <h4 class="subheading"><a name="TOC5"></a>Java-Specific Options</h4>
   1337  1.1  mrg 
   1338  1.1  mrg <p>The following option applies to the build of the Java front end.
   1339  1.7  mrg 
   1340  1.7  mrg      <dl>
   1341  1.7  mrg <dt><code>--disable-libgcj</code><dd>Specify that the run-time libraries
   1342  1.1  mrg used by GCJ should not be built.  This is useful in case you intend
   1343  1.7  mrg to use GCJ with some other run-time, or you're going to install it
   1344  1.1  mrg separately, or it just happens not to build on your particular
   1345  1.1  mrg machine.  In general, if the Java front end is enabled, the GCJ
   1346  1.7  mrg libraries will be enabled too, unless they're known to not work on
   1347  1.7  mrg the target platform.  If GCJ is enabled but &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo; isn't built, you
   1348  1.1  mrg may need to port it; in this case, before modifying the top-level
   1349  1.7  mrg <samp><span class="file">configure.ac</span></samp> so that &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo; is enabled by default on this platform,
   1350  1.7  mrg you may use <samp><span class="option">--enable-libgcj</span></samp> to override the default.
   1351  1.7  mrg 
   1352  1.7  mrg    </dl>
   1353  1.7  mrg 
   1354  1.7  mrg    <p>The following options apply to building &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo;.
   1355  1.7  mrg 
   1356  1.7  mrg <h5 class="subsubheading"><a name="TOC6"></a>General Options</h5>
   1357  1.1  mrg 
   1358  1.7  mrg      <dl>
   1359  1.7  mrg <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
   1360  1.7  mrg <samp><span class="file">.java</span></samp> source files to <samp><span class="file">.class</span></samp>.  Instead, it will use the
   1361  1.7  mrg <samp><span class="file">.class</span></samp> files from the source tree.  If you use this option you
   1362  1.7  mrg must have executables named <samp><span class="command">ecj1</span></samp> and <samp><span class="command">gjavah</span></samp> in your path
   1363  1.1  mrg for use by the build.  You must use this option if you intend to
   1364  1.7  mrg modify any <samp><span class="file">.java</span></samp> files in <samp><span class="file">libjava</span></samp>.
   1365  1.7  mrg 
   1366  1.7  mrg      <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
   1367  1.7  mrg &lsquo;<samp><span class="samp">java.home</span></samp>&rsquo; system property.  It is also used to set
   1368  1.7  mrg &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
   1369  1.7  mrg default &lsquo;<samp><span class="samp">java.home</span></samp>&rsquo; is set to <samp><var>prefix</var></samp> and
   1370  1.7  mrg &lsquo;<samp><span class="samp">sun.boot.class.path</span></samp>&rsquo; to
   1371  1.7  mrg <samp><var>datadir</var><span class="file">/java/libgcj-</span><var>version</var><span class="file">.jar</span></samp>.
   1372  1.7  mrg 
   1373  1.7  mrg      <br><dt><code>--with-ecj-jar=</code><var>filename</var><dd>This option can be used to specify the location of an external jar
   1374  1.1  mrg file containing the Eclipse Java compiler.  A specially modified
   1375  1.7  mrg version of this compiler is used by <samp><span class="command">gcj</span></samp> to parse
   1376  1.7  mrg <samp><span class="file">.java</span></samp> source files.  If this option is given, the
   1377  1.7  mrg &lsquo;<samp><span class="samp">libjava</span></samp>&rsquo; build will create and install an <samp><span class="file">ecj1</span></samp> executable
   1378  1.1  mrg which uses this jar file at runtime.
   1379  1.7  mrg 
   1380  1.7  mrg      <p>If this option is not given, but an <samp><span class="file">ecj.jar</span></samp> file is found in
   1381  1.7  mrg the topmost source tree at configure time, then the &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo;
   1382  1.7  mrg build will create and install <samp><span class="file">ecj1</span></samp>, and will also install the
   1383  1.7  mrg discovered <samp><span class="file">ecj.jar</span></samp> into a suitable place in the install tree.
   1384  1.7  mrg 
   1385  1.7  mrg      <p>If <samp><span class="file">ecj1</span></samp> is not installed, then the user will have to supply one
   1386  1.7  mrg on his path in order for <samp><span class="command">gcj</span></samp> to properly parse <samp><span class="file">.java</span></samp>
   1387  1.1  mrg source files.  A suitable jar is available from
   1388  1.1  mrg <a href="ftp://sourceware.org/pub/java/">ftp://sourceware.org/pub/java/</a>.
   1389  1.7  mrg 
   1390  1.7  mrg      <br><dt><code>--disable-getenv-properties</code><dd>Don't set system properties from <samp><span class="env">GCJ_PROPERTIES</span></samp>.
   1391  1.7  mrg 
   1392  1.7  mrg      <br><dt><code>--enable-hash-synchronization</code><dd>Use a global hash table for monitor locks.  Ordinarily,
   1393  1.7  mrg &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo;'s &lsquo;<samp><span class="samp">configure</span></samp>&rsquo; script automatically makes
   1394  1.1  mrg the correct choice for this option for your platform.  Only use
   1395  1.1  mrg this if you know you need the library to be configured differently.
   1396  1.7  mrg 
   1397  1.7  mrg      <br><dt><code>--enable-interpreter</code><dd>Enable the Java interpreter.  The interpreter is automatically
   1398  1.1  mrg enabled by default on all platforms that support it.  This option
   1399  1.1  mrg is really only useful if you want to disable the interpreter
   1400  1.7  mrg (using <samp><span class="option">--disable-interpreter</span></samp>).
   1401  1.7  mrg 
   1402  1.7  mrg      <br><dt><code>--disable-java-net</code><dd>Disable java.net.  This disables the native part of java.net only,
   1403  1.1  mrg using non-functional stubs for native method implementations.
   1404  1.7  mrg 
   1405  1.7  mrg      <br><dt><code>--disable-jvmpi</code><dd>Disable JVMPI support.
   1406  1.7  mrg 
   1407  1.7  mrg      <br><dt><code>--disable-libgcj-bc</code><dd>Disable BC ABI compilation of certain parts of libgcj.  By default,
   1408  1.7  mrg some portions of libgcj are compiled with <samp><span class="option">-findirect-dispatch</span></samp>
   1409  1.7  mrg and <samp><span class="option">-fno-indirect-classes</span></samp>, allowing them to be overridden at
   1410  1.1  mrg run-time.
   1411  1.7  mrg 
   1412  1.7  mrg      <p>If <samp><span class="option">--disable-libgcj-bc</span></samp> is specified, libgcj is built without
   1413  1.1  mrg these options.  This allows the compile-time linker to resolve
   1414  1.1  mrg dependencies when statically linking to libgcj.  However it makes it
   1415  1.1  mrg impossible to override the affected portions of libgcj at run-time.
   1416  1.7  mrg 
   1417  1.7  mrg      <br><dt><code>--enable-reduced-reflection</code><dd>Build most of libgcj with <samp><span class="option">-freduced-reflection</span></samp>.  This reduces
   1418  1.1  mrg the size of libgcj at the expense of not being able to do accurate
   1419  1.1  mrg reflection on the classes it contains.  This option is safe if you
   1420  1.1  mrg know that code using libgcj will never use reflection on the standard
   1421  1.1  mrg runtime classes in libgcj (including using serialization, RMI or CORBA).
   1422  1.7  mrg 
   1423  1.7  mrg      <br><dt><code>--with-ecos</code><dd>Enable runtime eCos target support.
   1424  1.7  mrg 
   1425  1.7  mrg      <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
   1426  1.7  mrg support as well, as these require &lsquo;<samp><span class="samp">libffi</span></samp>&rsquo; to work.
   1427  1.7  mrg 
   1428  1.7  mrg      <br><dt><code>--enable-libgcj-debug</code><dd>Enable runtime debugging code.
   1429  1.7  mrg 
   1430  1.7  mrg      <br><dt><code>--enable-libgcj-multifile</code><dd>If specified, causes all <samp><span class="file">.java</span></samp> source files to be
   1431  1.7  mrg compiled into <samp><span class="file">.class</span></samp> files in one invocation of
   1432  1.7  mrg &lsquo;<samp><span class="samp">gcj</span></samp>&rsquo;.  This can speed up build time, but is more
   1433  1.1  mrg resource-intensive.  If this option is unspecified or
   1434  1.7  mrg disabled, &lsquo;<samp><span class="samp">gcj</span></samp>&rsquo; is invoked once for each <samp><span class="file">.java</span></samp>
   1435  1.7  mrg file to compile into a <samp><span class="file">.class</span></samp> file.
   1436  1.7  mrg 
   1437  1.7  mrg      <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>.
   1438  1.7  mrg 
   1439  1.7  mrg      <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.
   1440  1.7  mrg 
   1441  1.7  mrg      <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
   1442  1.1  mrg characters and the Win32 API.
   1443  1.7  mrg 
   1444  1.7  mrg      <br><dt><code>--enable-java-home</code><dd>If enabled, this creates a JPackage compatible SDK environment during install. 
   1445  1.1  mrg Note that if &ndash;enable-java-home is used, &ndash;with-arch-directory=ARCH must also
   1446  1.1  mrg be specified.
   1447  1.7  mrg 
   1448  1.7  mrg      <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
   1449  1.1  mrg environment created when &ndash;enable-java-home is passed. Typical names for this
   1450  1.1  mrg directory include i386, amd64, ia64, etc.
   1451  1.7  mrg 
   1452  1.7  mrg      <br><dt><code>--with-os-directory=DIR</code><dd>Specifies the OS directory for the SDK include directory. This is set to auto
   1453  1.7  mrg detect, and is typically 'linux'.
   1454  1.7  mrg 
   1455  1.7  mrg      <br><dt><code>--with-origin-name=NAME</code><dd>Specifies the JPackage origin name. This defaults to the 'gcj' in
   1456  1.1  mrg java-1.5.0-gcj.
   1457  1.7  mrg 
   1458  1.7  mrg      <br><dt><code>--with-arch-suffix=SUFFIX</code><dd>Specifies the suffix for the sdk directory. Defaults to the empty string. 
   1459  1.7  mrg Examples include '.x86_64' in 'java-1.5.0-gcj-1.5.0.0.x86_64'.
   1460  1.7  mrg 
   1461  1.7  mrg      <br><dt><code>--with-jvm-root-dir=DIR</code><dd>Specifies where to install the SDK. Default is $(prefix)/lib/jvm.
   1462  1.7  mrg 
   1463  1.7  mrg      <br><dt><code>--with-jvm-jar-dir=DIR</code><dd>Specifies where to install jars. Default is $(prefix)/lib/jvm-exports.
   1464  1.7  mrg 
   1465  1.7  mrg      <br><dt><code>--with-python-dir=DIR</code><dd>Specifies where to install the Python modules used for aot-compile. DIR should
   1466  1.1  mrg not include the prefix used in installation. For example, if the Python modules
   1467  1.1  mrg are to be installed in /usr/lib/python2.5/site-packages, then
   1468  1.1  mrg &ndash;with-python-dir=/lib/python2.5/site-packages should be passed. If this is
   1469  1.1  mrg not specified, then the Python modules are installed in $(prefix)/share/python.
   1470  1.7  mrg 
   1471  1.7  mrg      <br><dt><code>--enable-aot-compile-rpm</code><dd>Adds aot-compile-rpm to the list of installed scripts.
   1472  1.7  mrg 
   1473  1.7  mrg      <br><dt><code>--enable-browser-plugin</code><dd>Build the gcjwebplugin web browser plugin.
   1474  1.7  mrg 
   1475  1.7  mrg      <br><dt><code>--enable-static-libjava</code><dd>Build static libraries in libjava. The default is to only build shared
   1476  1.3  mrg libraries.
   1477  1.7  mrg 
   1478  1.7  mrg           <dl>
   1479  1.7  mrg <dt><code>ansi</code><dd>Use the single-byte <code>char</code> and the Win32 A functions natively,
   1480  1.1  mrg translating to and from UNICODE when using these functions.  If
   1481  1.1  mrg unspecified, this is the default.
   1482  1.7  mrg 
   1483  1.7  mrg           <br><dt><code>unicows</code><dd>Use the <code>WCHAR</code> and Win32 W functions natively.  Adds
   1484  1.7  mrg <code>-lunicows</code> to <samp><span class="file">libgcj.spec</span></samp> to link with &lsquo;<samp><span class="samp">libunicows</span></samp>&rsquo;. 
   1485  1.7  mrg <samp><span class="file">unicows.dll</span></samp> needs to be deployed on Microsoft Windows 9X machines
   1486  1.7  mrg running built executables.  <samp><span class="file">libunicows.a</span></samp>, an open-source
   1487  1.7  mrg import library around Microsoft's <code>unicows.dll</code>, is obtained from
   1488  1.1  mrg <a href="http://libunicows.sourceforge.net/">http://libunicows.sourceforge.net/</a>, which also gives details
   1489  1.7  mrg on getting <samp><span class="file">unicows.dll</span></samp> from Microsoft.
   1490  1.7  mrg 
   1491  1.7  mrg           <br><dt><code>unicode</code><dd>Use the <code>WCHAR</code> and Win32 W functions natively.  Does <em>not</em>
   1492  1.7  mrg add <code>-lunicows</code> to <samp><span class="file">libgcj.spec</span></samp>.  The built executables will
   1493  1.7  mrg only run on Microsoft Windows NT and above. 
   1494  1.6  mrg </dl>
   1495  1.7  mrg      </dl>
   1496  1.1  mrg 
   1497  1.7  mrg <h5 class="subsubheading"><a name="TOC7"></a>AWT-Specific Options</h5>
   1498  1.1  mrg 
   1499  1.7  mrg      <dl>
   1500  1.7  mrg <dt><code>--with-x</code><dd>Use the X Window System.
   1501  1.1  mrg 
   1502  1.7  mrg      <br><dt><code>--enable-java-awt=PEER(S)</code><dd>Specifies the AWT peer library or libraries to build alongside
   1503  1.7  mrg &lsquo;<samp><span class="samp">libgcj</span></samp>&rsquo;.  If this option is unspecified or disabled, AWT
   1504  1.7  mrg will be non-functional.  Current valid values are <samp><span class="option">gtk</span></samp> and
   1505  1.7  mrg <samp><span class="option">xlib</span></samp>.  Multiple libraries should be separated by a
   1506  1.7  mrg comma (i.e. <samp><span class="option">--enable-java-awt=gtk,xlib</span></samp>).
   1507  1.1  mrg 
   1508  1.7  mrg      <br><dt><code>--enable-gtk-cairo</code><dd>Build the cairo Graphics2D implementation on GTK.
   1509  1.1  mrg 
   1510  1.7  mrg      <br><dt><code>--enable-java-gc=TYPE</code><dd>Choose garbage collector.  Defaults to <samp><span class="option">boehm</span></samp> if unspecified.
   1511  1.1  mrg 
   1512  1.7  mrg      <br><dt><code>--disable-gtktest</code><dd>Do not try to compile and run a test GTK+ program.
   1513  1.3  mrg 
   1514  1.7  mrg      <br><dt><code>--disable-glibtest</code><dd>Do not try to compile and run a test GLIB program.
   1515  1.3  mrg 
   1516  1.7  mrg      <br><dt><code>--with-libart-prefix=PFX</code><dd>Prefix where libart is installed (optional).
   1517  1.3  mrg 
   1518  1.7  mrg      <br><dt><code>--with-libart-exec-prefix=PFX</code><dd>Exec prefix where libart is installed (optional).
   1519  1.3  mrg 
   1520  1.7  mrg      <br><dt><code>--disable-libarttest</code><dd>Do not try to compile and run a test libart program.
   1521  1.3  mrg 
   1522  1.7  mrg </dl>
   1523  1.3  mrg 
   1524  1.7  mrg    <p><hr />
   1525  1.7  mrg <p><a href="./index.html">Return to the GCC Installation page</a>
   1526  1.1  mrg 
   1527  1.7  mrg <!-- ***Building**************************************************************** -->
   1528  1.7  mrg <!-- ***Testing***************************************************************** -->
   1529  1.7  mrg <!-- ***Final install*********************************************************** -->
   1530  1.7  mrg <!-- ***Binaries**************************************************************** -->
   1531  1.7  mrg <!-- ***Specific**************************************************************** -->
   1532  1.7  mrg <!-- ***Old documentation****************************************************** -->
   1533  1.7  mrg <!-- ***GFDL******************************************************************** -->
   1534  1.7  mrg <!-- *************************************************************************** -->
   1535  1.7  mrg <!-- Part 6 The End of the Document -->
   1536  1.7  mrg </body></html>
   1537  1.1  mrg 
   1538