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     12  1.1    mrg 
     13  1.1    mrg (a) The FSF's Front-Cover Text is:
     14  1.1    mrg 
     15  1.6    mrg A GNU Manual
     16  1.1    mrg 
     17  1.1    mrg (b) The FSF's Back-Cover Text is:
     18  1.1    mrg 
     19  1.6    mrg You have freedom to copy and modify this GNU Manual, like GNU
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     23  1.6    mrg <head>
     24  1.6    mrg <title>Installing GCC</title>
     25  1.6    mrg 
     26  1.6    mrg <meta name="description" content="Installing GCC">
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     61  1.1    mrg </head>
     62  1.6    mrg 
     63  1.6    mrg <body lang="en">
     64  1.6    mrg <h1 class="settitle" align="center">Installing GCC</h1>
     65  1.6    mrg 
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     82  1.6    mrg 
     83  1.6    mrg 
     84  1.6    mrg <a name="index-Configuration"></a>
     85  1.6    mrg <a name="index-Installing-GCC_003a-Configuration"></a>
     86  1.6    mrg 
     87  1.6    mrg <p>Like most GNU software, GCC must be configured before it can be built.
     88  1.1    mrg This document describes the recommended configuration procedure
     89  1.1    mrg for both native and cross targets.
     90  1.6    mrg </p>
     91  1.6    mrg <p>We use <var>srcdir</var> to refer to the toplevel source directory for
     92  1.1    mrg GCC; we use <var>objdir</var> to refer to the toplevel build/object directory.
     93  1.6    mrg </p>
     94  1.6    mrg <p>If you obtained the sources via SVN, <var>srcdir</var> must refer to the top
     95  1.6    mrg <samp>gcc</samp> directory, the one where the <samp>MAINTAINERS</samp> file can be
     96  1.6    mrg found, and not its <samp>gcc</samp> subdirectory, otherwise the build will fail.
     97  1.6    mrg </p>
     98  1.6    mrg <p>If either <var>srcdir</var> or <var>objdir</var> is located on an automounted NFS
     99  1.6    mrg file system, the shell&rsquo;s built-in <code>pwd</code> command will return
    100  1.1    mrg temporary pathnames.  Using these can lead to various sorts of build
    101  1.6    mrg problems.  To avoid this issue, set the <code>PWDCMD</code> environment
    102  1.6    mrg variable to an automounter-aware <code>pwd</code> command, e.g.,
    103  1.6    mrg <code>pawd</code> or &lsquo;<samp>amq -w</samp>&rsquo;, during the configuration and build
    104  1.1    mrg phases.
    105  1.6    mrg </p>
    106  1.6    mrg <p>First, we <strong>highly</strong> recommend that GCC be built into a
    107  1.1    mrg separate directory from the sources which does <strong>not</strong> reside
    108  1.1    mrg within the source tree.  This is how we generally build GCC; building
    109  1.6    mrg where <var>srcdir</var> == <var>objdir</var> should still work, but doesn&rsquo;t
    110  1.1    mrg get extensive testing; building where <var>objdir</var> is a subdirectory
    111  1.1    mrg of <var>srcdir</var> is unsupported.
    112  1.6    mrg </p>
    113  1.6    mrg <p>If you have previously built GCC in the same directory for a
    114  1.6    mrg different target machine, do &lsquo;<samp>make distclean</samp>&rsquo; to delete all files
    115  1.6    mrg that might be invalid.  One of the files this deletes is <samp>Makefile</samp>;
    116  1.6    mrg if &lsquo;<samp>make distclean</samp>&rsquo; complains that <samp>Makefile</samp> does not exist
    117  1.6    mrg or issues a message like &ldquo;don&rsquo;t know how to make distclean&rdquo; it probably
    118  1.1    mrg means that the directory is already suitably clean.  However, with the
    119  1.1    mrg recommended method of building in a separate <var>objdir</var>, you should
    120  1.1    mrg simply use a different <var>objdir</var> for each target.
    121  1.6    mrg </p>
    122  1.6    mrg <p>Second, when configuring a native system, either <code>cc</code> or
    123  1.6    mrg <code>gcc</code> must be in your path or you must set <code>CC</code> in
    124  1.1    mrg your environment before running configure.  Otherwise the configuration
    125  1.1    mrg scripts may fail.
    126  1.6    mrg </p>
    127  1.1    mrg 
    128  1.6    mrg <p>To configure GCC:
    129  1.6    mrg </p>
    130  1.6    mrg <div class="smallexample">
    131  1.6    mrg <pre class="smallexample">% mkdir <var>objdir</var>
    132  1.6    mrg % cd <var>objdir</var>
    133  1.6    mrg % <var>srcdir</var>/configure [<var>options</var>] [<var>target</var>]
    134  1.6    mrg </pre></div>
    135  1.1    mrg 
    136  1.6    mrg <a name="Distributor-options"></a>
    137  1.6    mrg <h3 class="heading">Distributor options</h3>
    138  1.1    mrg 
    139  1.1    mrg <p>If you will be distributing binary versions of GCC, with modifications
    140  1.1    mrg to the source code, you should use the options described in this
    141  1.1    mrg section to make clear that your version contains modifications.
    142  1.6    mrg </p>
    143  1.6    mrg <dl compact="compact">
    144  1.6    mrg <dt><code>--with-pkgversion=<var>version</var></code></dt>
    145  1.6    mrg <dd><p>Specify a string that identifies your package.  You may wish
    146  1.1    mrg to include a build number or build date.  This version string will be
    147  1.6    mrg included in the output of <code>gcc --version</code>.  This suffix does
    148  1.6    mrg not replace the default version string, only the &lsquo;<samp>GCC</samp>&rsquo; part.
    149  1.6    mrg </p>
    150  1.6    mrg <p>The default value is &lsquo;<samp>GCC</samp>&rsquo;.
    151  1.6    mrg </p>
    152  1.6    mrg </dd>
    153  1.6    mrg <dt><code>--with-bugurl=<var>url</var></code></dt>
    154  1.6    mrg <dd><p>Specify the URL that users should visit if they wish to report a bug.
    155  1.1    mrg You are of course welcome to forward bugs reported to you to the FSF,
    156  1.1    mrg if you determine that they are not bugs in your modifications.
    157  1.6    mrg </p>
    158  1.6    mrg <p>The default value refers to the FSF&rsquo;s GCC bug tracker.
    159  1.6    mrg </p>
    160  1.6    mrg </dd>
    161  1.6    mrg </dl>
    162  1.1    mrg 
    163  1.6    mrg <a name="Target-specification"></a>
    164  1.6    mrg <h3 class="heading">Target specification</h3>
    165  1.6    mrg <ul>
    166  1.6    mrg <li> GCC has code to correctly determine the correct value for <var>target</var>
    167  1.1    mrg for nearly all native systems.  Therefore, we highly recommend you do
    168  1.1    mrg not provide a configure target when configuring a native compiler.
    169  1.1    mrg 
    170  1.6    mrg </li><li> <var>target</var> must be specified as <samp>--target=<var>target</var></samp>
    171  1.1    mrg when configuring a cross compiler; examples of valid targets would be
    172  1.1    mrg m68k-elf, sh-elf, etc.
    173  1.1    mrg 
    174  1.6    mrg </li><li> Specifying just <var>target</var> instead of <samp>--target=<var>target</var></samp>
    175  1.6    mrg implies that the host defaults to <var>target</var>.
    176  1.6    mrg </li></ul>
    177  1.6    mrg 
    178  1.1    mrg 
    179  1.6    mrg <a name="Options-specification"></a>
    180  1.6    mrg <h3 class="heading">Options specification</h3>
    181  1.1    mrg 
    182  1.1    mrg <p>Use <var>options</var> to override several configure time options for
    183  1.6    mrg GCC.  A list of supported <var>options</var> follows; &lsquo;<samp>configure
    184  1.6    mrg --help</samp>&rsquo; may list other options, but those not listed below may not
    185  1.1    mrg work and should not normally be used.
    186  1.6    mrg </p>
    187  1.6    mrg <p>Note that each <samp>--enable</samp> option has a corresponding
    188  1.6    mrg <samp>--disable</samp> option and that each <samp>--with</samp> option has a
    189  1.6    mrg corresponding <samp>--without</samp> option.
    190  1.6    mrg </p>
    191  1.6    mrg <dl compact="compact">
    192  1.6    mrg <dt><code>--prefix=<var>dirname</var></code></dt>
    193  1.6    mrg <dd><p>Specify the toplevel installation
    194  1.1    mrg directory.  This is the recommended way to install the tools into a directory
    195  1.1    mrg other than the default.  The toplevel installation directory defaults to
    196  1.6    mrg <samp>/usr/local</samp>.
    197  1.6    mrg </p>
    198  1.6    mrg <p>We <strong>highly</strong> recommend against <var>dirname</var> being the same or a
    199  1.1    mrg subdirectory of <var>objdir</var> or vice versa.  If specifying a directory
    200  1.6    mrg beneath a user&rsquo;s home directory tree, some shells will not expand
    201  1.6    mrg <var>dirname</var> correctly if it contains the &lsquo;<samp>~</samp>&rsquo; metacharacter; use
    202  1.6    mrg <code>$HOME</code> instead.
    203  1.6    mrg </p>
    204  1.6    mrg <p>The following standard <code>autoconf</code> options are supported.  Normally you
    205  1.1    mrg should not need to use these options.
    206  1.6    mrg </p><dl compact="compact">
    207  1.6    mrg <dt><code>--exec-prefix=<var>dirname</var></code></dt>
    208  1.6    mrg <dd><p>Specify the toplevel installation directory for architecture-dependent
    209  1.1    mrg files.  The default is <samp><var>prefix</var></samp>.
    210  1.6    mrg </p>
    211  1.6    mrg </dd>
    212  1.6    mrg <dt><code>--bindir=<var>dirname</var></code></dt>
    213  1.6    mrg <dd><p>Specify the installation directory for the executables called by users
    214  1.6    mrg (such as <code>gcc</code> and <code>g++</code>).  The default is
    215  1.6    mrg <samp><var>exec-prefix</var>/bin</samp>.
    216  1.6    mrg </p>
    217  1.6    mrg </dd>
    218  1.6    mrg <dt><code>--libdir=<var>dirname</var></code></dt>
    219  1.6    mrg <dd><p>Specify the installation directory for object code libraries and
    220  1.6    mrg internal data files of GCC.  The default is <samp><var>exec-prefix</var>/lib</samp>.
    221  1.6    mrg </p>
    222  1.6    mrg </dd>
    223  1.6    mrg <dt><code>--libexecdir=<var>dirname</var></code></dt>
    224  1.6    mrg <dd><p>Specify the installation directory for internal executables of GCC.
    225  1.6    mrg The default is <samp><var>exec-prefix</var>/libexec</samp>.
    226  1.6    mrg </p>
    227  1.6    mrg </dd>
    228  1.6    mrg <dt><code>--with-slibdir=<var>dirname</var></code></dt>
    229  1.6    mrg <dd><p>Specify the installation directory for the shared libgcc library.  The
    230  1.1    mrg default is <samp><var>libdir</var></samp>.
    231  1.6    mrg </p>
    232  1.6    mrg </dd>
    233  1.6    mrg <dt><code>--datarootdir=<var>dirname</var></code></dt>
    234  1.6    mrg <dd><p>Specify the root of the directory tree for read-only architecture-independent
    235  1.6    mrg data files referenced by GCC.  The default is <samp><var>prefix</var>/share</samp>.
    236  1.6    mrg </p>
    237  1.6    mrg </dd>
    238  1.6    mrg <dt><code>--infodir=<var>dirname</var></code></dt>
    239  1.6    mrg <dd><p>Specify the installation directory for documentation in info format.
    240  1.6    mrg The default is <samp><var>datarootdir</var>/info</samp>.
    241  1.6    mrg </p>
    242  1.6    mrg </dd>
    243  1.6    mrg <dt><code>--datadir=<var>dirname</var></code></dt>
    244  1.6    mrg <dd><p>Specify the installation directory for some architecture-independent
    245  1.1    mrg data files referenced by GCC.  The default is <samp><var>datarootdir</var></samp>.
    246  1.6    mrg </p>
    247  1.6    mrg </dd>
    248  1.6    mrg <dt><code>--docdir=<var>dirname</var></code></dt>
    249  1.6    mrg <dd><p>Specify the installation directory for documentation files (other
    250  1.6    mrg than Info) for GCC.  The default is <samp><var>datarootdir</var>/doc</samp>.
    251  1.6    mrg </p>
    252  1.6    mrg </dd>
    253  1.6    mrg <dt><code>--htmldir=<var>dirname</var></code></dt>
    254  1.6    mrg <dd><p>Specify the installation directory for HTML documentation files.
    255  1.1    mrg The default is <samp><var>docdir</var></samp>.
    256  1.6    mrg </p>
    257  1.6    mrg </dd>
    258  1.6    mrg <dt><code>--pdfdir=<var>dirname</var></code></dt>
    259  1.6    mrg <dd><p>Specify the installation directory for PDF documentation files.
    260  1.1    mrg The default is <samp><var>docdir</var></samp>.
    261  1.6    mrg </p>
    262  1.6    mrg </dd>
    263  1.6    mrg <dt><code>--mandir=<var>dirname</var></code></dt>
    264  1.6    mrg <dd><p>Specify the installation directory for manual pages.  The default is
    265  1.6    mrg <samp><var>datarootdir</var>/man</samp>.  (Note that the manual pages are only extracts
    266  1.1    mrg from the full GCC manuals, which are provided in Texinfo format.  The manpages
    267  1.1    mrg are derived by an automatic conversion process from parts of the full
    268  1.1    mrg manual.)
    269  1.6    mrg </p>
    270  1.6    mrg </dd>
    271  1.6    mrg <dt><code>--with-gxx-include-dir=<var>dirname</var></code></dt>
    272  1.6    mrg <dd><p>Specify
    273  1.1    mrg the installation directory for G++ header files.  The default depends
    274  1.1    mrg on other configuration options, and differs between cross and native
    275  1.1    mrg configurations.
    276  1.6    mrg </p>
    277  1.6    mrg </dd>
    278  1.6    mrg <dt><code>--with-specs=<var>specs</var></code></dt>
    279  1.6    mrg <dd><p>Specify additional command line driver SPECS.
    280  1.3  skrll This can be useful if you need to turn on a non-standard feature by
    281  1.6    mrg default without modifying the compiler&rsquo;s source code, for instance
    282  1.6    mrg <samp>--with-specs=%{!fcommon:%{!fno-common:-fno-common}}</samp>.
    283  1.3  skrll See &ldquo;Spec Files&rdquo; in the main manual
    284  1.6    mrg </p>
    285  1.6    mrg </dd>
    286  1.6    mrg </dl>
    287  1.3  skrll 
    288  1.6    mrg </dd>
    289  1.6    mrg <dt><code>--program-prefix=<var>prefix</var></code></dt>
    290  1.6    mrg <dd><p>GCC supports some transformations of the names of its programs when
    291  1.1    mrg installing them.  This option prepends <var>prefix</var> to the names of
    292  1.1    mrg programs to install in <var>bindir</var> (see above).  For example, specifying
    293  1.6    mrg <samp>--program-prefix=foo-</samp> would result in &lsquo;<samp>gcc</samp>&rsquo;
    294  1.6    mrg being installed as <samp>/usr/local/bin/foo-gcc</samp>.
    295  1.6    mrg </p>
    296  1.6    mrg </dd>
    297  1.6    mrg <dt><code>--program-suffix=<var>suffix</var></code></dt>
    298  1.6    mrg <dd><p>Appends <var>suffix</var> to the names of programs to install in <var>bindir</var>
    299  1.6    mrg (see above).  For example, specifying <samp>--program-suffix=-3.1</samp>
    300  1.6    mrg would result in &lsquo;<samp>gcc</samp>&rsquo; being installed as
    301  1.6    mrg <samp>/usr/local/bin/gcc-3.1</samp>.
    302  1.6    mrg </p>
    303  1.6    mrg </dd>
    304  1.6    mrg <dt><code>--program-transform-name=<var>pattern</var></code></dt>
    305  1.6    mrg <dd><p>Applies the &lsquo;<samp>sed</samp>&rsquo; script <var>pattern</var> to be applied to the names
    306  1.1    mrg of programs to install in <var>bindir</var> (see above).  <var>pattern</var> has to
    307  1.6    mrg consist of one or more basic &lsquo;<samp>sed</samp>&rsquo; editing commands, separated by
    308  1.6    mrg semicolons.  For example, if you want the &lsquo;<samp>gcc</samp>&rsquo; program name to be
    309  1.6    mrg transformed to the installed program <samp>/usr/local/bin/myowngcc</samp> and
    310  1.6    mrg the &lsquo;<samp>g++</samp>&rsquo; program name to be transformed to
    311  1.6    mrg <samp>/usr/local/bin/gspecial++</samp> without changing other program names,
    312  1.1    mrg you could use the pattern
    313  1.6    mrg <samp>--program-transform-name='s/^gcc$/myowngcc/; s/^g++$/gspecial++/'</samp>
    314  1.1    mrg to achieve this effect.
    315  1.6    mrg </p>
    316  1.6    mrg <p>All three options can be combined and used together, resulting in more
    317  1.1    mrg complex conversion patterns.  As a basic rule, <var>prefix</var> (and
    318  1.1    mrg <var>suffix</var>) are prepended (appended) before further transformations
    319  1.1    mrg can happen with a special transformation script <var>pattern</var>.
    320  1.6    mrg </p>
    321  1.6    mrg <p>As currently implemented, this option only takes effect for native
    322  1.6    mrg builds; cross compiler binaries&rsquo; names are not transformed even when a
    323  1.1    mrg transformation is explicitly asked for by one of these options.
    324  1.6    mrg </p>
    325  1.6    mrg <p>For native builds, some of the installed programs are also installed
    326  1.1    mrg with the target alias in front of their name, as in
    327  1.6    mrg &lsquo;<samp>i686-pc-linux-gnu-gcc</samp>&rsquo;.  All of the above transformations happen
    328  1.1    mrg before the target alias is prepended to the name&mdash;so, specifying
    329  1.6    mrg <samp>--program-prefix=foo-</samp> and <samp>program-suffix=-3.1</samp>, the
    330  1.1    mrg resulting binary would be installed as
    331  1.6    mrg <samp>/usr/local/bin/i686-pc-linux-gnu-foo-gcc-3.1</samp>.
    332  1.6    mrg </p>
    333  1.6    mrg <p>As a last shortcoming, none of the installed Ada programs are
    334  1.1    mrg transformed yet, which will be fixed in some time.
    335  1.6    mrg </p>
    336  1.6    mrg </dd>
    337  1.6    mrg <dt><code>--with-local-prefix=<var>dirname</var></code></dt>
    338  1.6    mrg <dd><p>Specify the
    339  1.1    mrg installation directory for local include files.  The default is
    340  1.6    mrg <samp>/usr/local</samp>.  Specify this option if you want the compiler to
    341  1.6    mrg search directory <samp><var>dirname</var>/include</samp> for locally installed
    342  1.6    mrg header files <em>instead</em> of <samp>/usr/local/include</samp>.
    343  1.6    mrg </p>
    344  1.6    mrg <p>You should specify <samp>--with-local-prefix</samp> <strong>only</strong> if your
    345  1.6    mrg site has a different convention (not <samp>/usr/local</samp>) for where to put
    346  1.1    mrg site-specific files.
    347  1.6    mrg </p>
    348  1.6    mrg <p>The default value for <samp>--with-local-prefix</samp> is <samp>/usr/local</samp>
    349  1.6    mrg regardless of the value of <samp>--prefix</samp>.  Specifying
    350  1.6    mrg <samp>--prefix</samp> has no effect on which directory GCC searches for
    351  1.1    mrg local header files.  This may seem counterintuitive, but actually it is
    352  1.1    mrg logical.
    353  1.6    mrg </p>
    354  1.6    mrg <p>The purpose of <samp>--prefix</samp> is to specify where to <em>install
    355  1.6    mrg GCC</em>.  The local header files in <samp>/usr/local/include</samp>&mdash;if you put
    356  1.1    mrg any in that directory&mdash;are not part of GCC.  They are part of other
    357  1.1    mrg programs&mdash;perhaps many others.  (GCC installs its own header files in
    358  1.6    mrg another directory which is based on the <samp>--prefix</samp> value.)
    359  1.6    mrg </p>
    360  1.6    mrg <p>Both the local-prefix include directory and the GCC-prefix include
    361  1.6    mrg directory are part of GCC&rsquo;s &ldquo;system include&rdquo; directories.  Although these
    362  1.1    mrg two directories are not fixed, they need to be searched in the proper
    363  1.1    mrg order for the correct processing of the include_next directive.  The
    364  1.1    mrg local-prefix include directory is searched before the GCC-prefix
    365  1.1    mrg include directory.  Another characteristic of system include directories
    366  1.1    mrg is that pedantic warnings are turned off for headers in these directories.
    367  1.6    mrg </p>
    368  1.6    mrg <p>Some autoconf macros add <samp>-I <var>directory</var></samp> options to the
    369  1.1    mrg compiler command line, to ensure that directories containing installed
    370  1.6    mrg packages&rsquo; headers are searched.  When <var>directory</var> is one of GCC&rsquo;s
    371  1.1    mrg system include directories, GCC will ignore the option so that system
    372  1.1    mrg directories continue to be processed in the correct order.  This
    373  1.1    mrg may result in a search order different from what was specified but the
    374  1.1    mrg directory will still be searched.
    375  1.6    mrg </p>
    376  1.6    mrg <p>GCC automatically searches for ordinary libraries using
    377  1.6    mrg <code>GCC_EXEC_PREFIX</code>.  Thus, when the same installation prefix is
    378  1.1    mrg used for both GCC and packages, GCC will automatically search for
    379  1.1    mrg both headers and libraries.  This provides a configuration that is
    380  1.1    mrg easy to use.  GCC behaves in a manner similar to that when it is
    381  1.6    mrg installed as a system compiler in <samp>/usr</samp>.
    382  1.6    mrg </p>
    383  1.6    mrg <p>Sites that need to install multiple versions of GCC may not want to
    384  1.1    mrg use the above simple configuration.  It is possible to use the
    385  1.6    mrg <samp>--program-prefix</samp>, <samp>--program-suffix</samp> and
    386  1.6    mrg <samp>--program-transform-name</samp> options to install multiple versions
    387  1.1    mrg into a single directory, but it may be simpler to use different prefixes
    388  1.6    mrg and the <samp>--with-local-prefix</samp> option to specify the location of the
    389  1.1    mrg site-specific files for each version.  It will then be necessary for
    390  1.1    mrg users to specify explicitly the location of local site libraries
    391  1.6    mrg (e.g., with <code>LIBRARY_PATH</code>).
    392  1.6    mrg </p>
    393  1.6    mrg <p>The same value can be used for both <samp>--with-local-prefix</samp> and
    394  1.6    mrg <samp>--prefix</samp> provided it is not <samp>/usr</samp>.  This can be used
    395  1.6    mrg to avoid the default search of <samp>/usr/local/include</samp>.
    396  1.6    mrg </p>
    397  1.6    mrg <p><strong>Do not</strong> specify <samp>/usr</samp> as the <samp>--with-local-prefix</samp>!
    398  1.6    mrg The directory you use for <samp>--with-local-prefix</samp> <strong>must not</strong>
    399  1.6    mrg contain any of the system&rsquo;s standard header files.  If it did contain
    400  1.1    mrg them, certain programs would be miscompiled (including GNU Emacs, on
    401  1.1    mrg certain targets), because this would override and nullify the header
    402  1.6    mrg file corrections made by the <code>fixincludes</code> script.
    403  1.6    mrg </p>
    404  1.6    mrg <p>Indications are that people who use this option use it based on mistaken
    405  1.1    mrg ideas of what it is for.  People use it as if it specified where to
    406  1.1    mrg install part of GCC.  Perhaps they make this assumption because
    407  1.1    mrg installing GCC creates the directory.
    408  1.6    mrg </p>
    409  1.6    mrg </dd>
    410  1.6    mrg <dt><code>--with-native-system-header-dir=<var>dirname</var></code></dt>
    411  1.6    mrg <dd><p>Specifies that <var>dirname</var> is the directory that contains native system
    412  1.6    mrg header files, rather than <samp>/usr/include</samp>.  This option is most useful
    413  1.3  skrll if you are creating a compiler that should be isolated from the system
    414  1.3  skrll as much as possible.  It is most commonly used with the
    415  1.6    mrg <samp>--with-sysroot</samp> option and will cause GCC to search
    416  1.3  skrll <var>dirname</var> inside the system root specified by that option.
    417  1.6    mrg </p>
    418  1.6    mrg </dd>
    419  1.6    mrg <dt><code>--enable-shared[=<var>package</var>[,&hellip;]]</code></dt>
    420  1.6    mrg <dd><p>Build shared versions of libraries, if shared libraries are supported on
    421  1.1    mrg the target platform.  Unlike GCC 2.95.x and earlier, shared libraries
    422  1.1    mrg are enabled by default on all platforms that support shared libraries.
    423  1.6    mrg </p>
    424  1.6    mrg <p>If a list of packages is given as an argument, build shared libraries
    425  1.1    mrg only for the listed packages.  For other packages, only static libraries
    426  1.1    mrg will be built.  Package names currently recognized in the GCC tree are
    427  1.6    mrg &lsquo;<samp>libgcc</samp>&rsquo; (also known as &lsquo;<samp>gcc</samp>&rsquo;), &lsquo;<samp>libstdc++</samp>&rsquo; (not
    428  1.6    mrg &lsquo;<samp>libstdc++-v3</samp>&rsquo;), &lsquo;<samp>libffi</samp>&rsquo;, &lsquo;<samp>zlib</samp>&rsquo;, &lsquo;<samp>boehm-gc</samp>&rsquo;,
    429  1.6    mrg &lsquo;<samp>ada</samp>&rsquo;, &lsquo;<samp>libada</samp>&rsquo;, &lsquo;<samp>libjava</samp>&rsquo;, &lsquo;<samp>libgo</samp>&rsquo;, and &lsquo;<samp>libobjc</samp>&rsquo;.
    430  1.6    mrg Note &lsquo;<samp>libiberty</samp>&rsquo; does not support shared libraries at all.
    431  1.6    mrg </p>
    432  1.6    mrg <p>Use <samp>--disable-shared</samp> to build only static libraries.  Note that
    433  1.6    mrg <samp>--disable-shared</samp> does not accept a list of package names as
    434  1.6    mrg argument, only <samp>--enable-shared</samp> does.
    435  1.6    mrg </p>
    436  1.6    mrg <p>Contrast with <samp>--enable-host-shared</samp>, which affects <em>host</em>
    437  1.5    mrg code.
    438  1.6    mrg </p>
    439  1.6    mrg </dd>
    440  1.6    mrg <dt><code>--enable-host-shared</code></dt>
    441  1.6    mrg <dd><p>Specify that the <em>host</em> code should be built into position-independent
    442  1.5    mrg machine code (with -fPIC), allowing it to be used within shared libraries,
    443  1.5    mrg but yielding a slightly slower compiler.
    444  1.6    mrg </p>
    445  1.6    mrg <p>This option is required when building the libgccjit.so library.
    446  1.6    mrg </p>
    447  1.6    mrg <p>Contrast with <samp>--enable-shared</samp>, which affects <em>target</em>
    448  1.5    mrg libraries.
    449  1.6    mrg </p>
    450  1.6    mrg </dd>
    451  1.6    mrg <dt><code><a name="with_002dgnu_002das"></a>--with-gnu-as</code></dt>
    452  1.6    mrg <dd><p>Specify that the compiler should assume that the
    453  1.1    mrg assembler it finds is the GNU assembler.  However, this does not modify
    454  1.1    mrg the rules to find an assembler and will result in confusion if the
    455  1.1    mrg assembler found is not actually the GNU assembler.  (Confusion may also
    456  1.1    mrg result if the compiler finds the GNU assembler but has not been
    457  1.6    mrg configured with <samp>--with-gnu-as</samp>.)  If you have more than one
    458  1.1    mrg assembler installed on your system, you may want to use this option in
    459  1.6    mrg connection with <samp>--with-as=<var>pathname</var></samp> or
    460  1.6    mrg <samp>--with-build-time-tools=<var>pathname</var></samp>.
    461  1.6    mrg </p>
    462  1.6    mrg <p>The following systems are the only ones where it makes a difference
    463  1.1    mrg whether you use the GNU assembler.  On any other system,
    464  1.6    mrg <samp>--with-gnu-as</samp> has no effect.
    465  1.6    mrg </p>
    466  1.6    mrg <ul>
    467  1.6    mrg <li> &lsquo;<samp>hppa1.0-<var>any</var>-<var>any</var></samp>&rsquo;
    468  1.6    mrg </li><li> &lsquo;<samp>hppa1.1-<var>any</var>-<var>any</var></samp>&rsquo;
    469  1.6    mrg </li><li> &lsquo;<samp>sparc-sun-solaris2.<var>any</var></samp>&rsquo;
    470  1.6    mrg </li><li> &lsquo;<samp>sparc64-<var>any</var>-solaris2.<var>any</var></samp>&rsquo;
    471  1.6    mrg </li></ul>
    472  1.6    mrg 
    473  1.6    mrg </dd>
    474  1.6    mrg <dt><code><a name="with_002das"></a>--with-as=<var>pathname</var></code></dt>
    475  1.6    mrg <dd><p>Specify that the compiler should use the assembler pointed to by
    476  1.1    mrg <var>pathname</var>, rather than the one found by the standard rules to find
    477  1.1    mrg an assembler, which are:
    478  1.6    mrg </p><ul>
    479  1.6    mrg <li> Unless GCC is being built with a cross compiler, check the
    480  1.6    mrg <samp><var>libexec</var>/gcc/<var>target</var>/<var>version</var></samp> directory.
    481  1.6    mrg <var>libexec</var> defaults to <samp><var>exec-prefix</var>/libexec</samp>;
    482  1.1    mrg <var>exec-prefix</var> defaults to <var>prefix</var>, which
    483  1.6    mrg defaults to <samp>/usr/local</samp> unless overridden by the
    484  1.6    mrg <samp>--prefix=<var>pathname</var></samp> switch described above.  <var>target</var>
    485  1.6    mrg is the target system triple, such as &lsquo;<samp>sparc-sun-solaris2.7</samp>&rsquo;, and
    486  1.1    mrg <var>version</var> denotes the GCC version, such as 3.0.
    487  1.1    mrg 
    488  1.6    mrg </li><li> If the target system is the same that you are building on, check
    489  1.6    mrg operating system specific directories (e.g. <samp>/usr/ccs/bin</samp> on
    490  1.1    mrg Sun Solaris 2).
    491  1.1    mrg 
    492  1.6    mrg </li><li> Check in the <code>PATH</code> for a tool whose name is prefixed by the
    493  1.1    mrg target system triple.
    494  1.1    mrg 
    495  1.6    mrg </li><li> Check in the <code>PATH</code> for a tool whose name is not prefixed by the
    496  1.1    mrg target system triple, if the host and target system triple are
    497  1.1    mrg the same (in other words, we use a host tool if it can be used for
    498  1.6    mrg the target as well).
    499  1.6    mrg </li></ul>
    500  1.1    mrg 
    501  1.6    mrg <p>You may want to use <samp>--with-as</samp> if no assembler
    502  1.1    mrg is installed in the directories listed above, or if you have multiple
    503  1.1    mrg assemblers installed and want to choose one that is not found by the
    504  1.1    mrg above rules.
    505  1.6    mrg </p>
    506  1.6    mrg </dd>
    507  1.6    mrg <dt><code><a name="with_002dgnu_002dld"></a>--with-gnu-ld</code></dt>
    508  1.6    mrg <dd><p>Same as <a href="#with-gnu-as"><samp>--with-gnu-as</samp></a>
    509  1.1    mrg but for the linker.
    510  1.6    mrg </p>
    511  1.6    mrg </dd>
    512  1.6    mrg <dt><code>--with-ld=<var>pathname</var></code></dt>
    513  1.6    mrg <dd><p>Same as <a href="#with-as"><samp>--with-as</samp></a>
    514  1.1    mrg but for the linker.
    515  1.6    mrg </p>
    516  1.6    mrg </dd>
    517  1.6    mrg <dt><code>--with-stabs</code></dt>
    518  1.6    mrg <dd><p>Specify that stabs debugging
    519  1.1    mrg information should be used instead of whatever format the host normally
    520  1.1    mrg uses.  Normally GCC uses the same debug format as the host system.
    521  1.6    mrg </p>
    522  1.6    mrg <p>On MIPS based systems and on Alphas, you must specify whether you want
    523  1.1    mrg GCC to create the normal ECOFF debugging format, or to use BSD-style
    524  1.1    mrg stabs passed through the ECOFF symbol table.  The normal ECOFF debug
    525  1.1    mrg format cannot fully handle languages other than C.  BSD stabs format can
    526  1.1    mrg handle other languages, but it only works with the GNU debugger GDB.
    527  1.6    mrg </p>
    528  1.6    mrg <p>Normally, GCC uses the ECOFF debugging format by default; if you
    529  1.6    mrg prefer BSD stabs, specify <samp>--with-stabs</samp> when you configure GCC.
    530  1.6    mrg </p>
    531  1.6    mrg <p>No matter which default you choose when you configure GCC, the user
    532  1.6    mrg can use the <samp>-gcoff</samp> and <samp>-gstabs+</samp> options to specify explicitly
    533  1.1    mrg the debug format for a particular compilation.
    534  1.6    mrg </p>
    535  1.6    mrg <p><samp>--with-stabs</samp> is meaningful on the ISC system on the 386, also, if
    536  1.6    mrg <samp>--with-gas</samp> is used.  It selects use of stabs debugging
    537  1.1    mrg information embedded in COFF output.  This kind of debugging information
    538  1.1    mrg supports C++ well; ordinary COFF debugging information does not.
    539  1.6    mrg </p>
    540  1.6    mrg <p><samp>--with-stabs</samp> is also meaningful on 386 systems running SVR4.  It
    541  1.1    mrg selects use of stabs debugging information embedded in ELF output.  The
    542  1.1    mrg C++ compiler currently (2.6.0) does not support the DWARF debugging
    543  1.1    mrg information normally used on 386 SVR4 platforms; stabs provide a
    544  1.1    mrg workable alternative.  This requires gas and gdb, as the normal SVR4
    545  1.1    mrg tools can not generate or interpret stabs.
    546  1.6    mrg </p>
    547  1.6    mrg </dd>
    548  1.6    mrg <dt><code>--with-tls=<var>dialect</var></code></dt>
    549  1.6    mrg <dd><p>Specify the default TLS dialect, for systems were there is a choice.
    550  1.3  skrll For ARM targets, possible values for <var>dialect</var> are <code>gnu</code> or
    551  1.3  skrll <code>gnu2</code>, which select between the original GNU dialect and the GNU TLS
    552  1.3  skrll descriptor-based dialect.
    553  1.6    mrg </p>
    554  1.6    mrg </dd>
    555  1.6    mrg <dt><code>--enable-multiarch</code></dt>
    556  1.6    mrg <dd><p>Specify whether to enable or disable multiarch support.  The default is
    557  1.3  skrll to check for glibc start files in a multiarch location, and enable it
    558  1.3  skrll if the files are found.  The auto detection is enabled for native builds,
    559  1.6    mrg and for cross builds configured with <samp>--with-sysroot</samp>, and without
    560  1.6    mrg <samp>--with-native-system-header-dir</samp>.
    561  1.3  skrll More documentation about multiarch can be found at
    562  1.3  skrll <a href="http://wiki.debian.org/Multiarch">http://wiki.debian.org/Multiarch</a>.
    563  1.6    mrg </p>
    564  1.6    mrg </dd>
    565  1.6    mrg <dt><code>--enable-sjlj-exceptions</code></dt>
    566  1.6    mrg <dd><p>Force use of the <code>setjmp</code>/<code>longjmp</code>-based scheme for exceptions.
    567  1.6    mrg &lsquo;<samp>configure</samp>&rsquo; ordinarily picks the correct value based on the platform.
    568  1.6    mrg Only use this option if you are sure you need a different setting.
    569  1.6    mrg </p>
    570  1.6    mrg </dd>
    571  1.6    mrg <dt><code>--enable-vtable-verify</code></dt>
    572  1.6    mrg <dd><p>Specify whether to enable or disable the vtable verification feature.
    573  1.5    mrg Enabling this feature causes libstdc++ to be built with its virtual calls
    574  1.5    mrg in verifiable mode.  This means that, when linked with libvtv, every
    575  1.5    mrg virtual call in libstdc++ will verify the vtable pointer through which the
    576  1.5    mrg call will be made before actually making the call.  If not linked with libvtv,
    577  1.6    mrg the verifier will call stub functions (in libstdc++ itself) and do nothing.
    578  1.5    mrg If vtable verification is disabled, then libstdc++ is not built with its
    579  1.5    mrg virtual calls in verifiable mode at all.  However the libvtv library will
    580  1.6    mrg still be built (see <samp>--disable-libvtv</samp> to turn off building libvtv).
    581  1.6    mrg <samp>--disable-vtable-verify</samp> is the default.
    582  1.6    mrg </p>
    583  1.6    mrg </dd>
    584  1.6    mrg <dt><code>--disable-multilib</code></dt>
    585  1.6    mrg <dd><p>Specify that multiple target
    586  1.1    mrg libraries to support different target variants, calling
    587  1.1    mrg conventions, etc. should not be built.  The default is to build a
    588  1.1    mrg predefined set of them.
    589  1.6    mrg </p>
    590  1.6    mrg <p>Some targets provide finer-grained control over which multilibs are built
    591  1.6    mrg (e.g., <samp>--disable-softfloat</samp>):
    592  1.6    mrg </p><dl compact="compact">
    593  1.6    mrg <dt><code>arm-*-*</code></dt>
    594  1.6    mrg <dd><p>fpu, 26bit, underscore, interwork, biendian, nofmult.
    595  1.6    mrg </p>
    596  1.6    mrg </dd>
    597  1.6    mrg <dt><code>m68*-*-*</code></dt>
    598  1.6    mrg <dd><p>softfloat, m68881, m68000, m68020.
    599  1.6    mrg </p>
    600  1.6    mrg </dd>
    601  1.6    mrg <dt><code>mips*-*-*</code></dt>
    602  1.6    mrg <dd><p>single-float, biendian, softfloat.
    603  1.6    mrg </p>
    604  1.6    mrg </dd>
    605  1.6    mrg <dt><code>powerpc*-*-*, rs6000*-*-*</code></dt>
    606  1.6    mrg <dd><p>aix64, pthread, softfloat, powercpu, powerpccpu, powerpcos, biendian,
    607  1.1    mrg sysv, aix.
    608  1.6    mrg </p>
    609  1.6    mrg </dd>
    610  1.6    mrg </dl>
    611  1.1    mrg 
    612  1.6    mrg </dd>
    613  1.6    mrg <dt><code>--with-multilib-list=<var>list</var></code></dt>
    614  1.6    mrg <dt><code>--without-multilib-list</code></dt>
    615  1.6    mrg <dd><p>Specify what multilibs to build.
    616  1.3  skrll Currently only implemented for sh*-*-* and x86-64-*-linux*.
    617  1.6    mrg </p>
    618  1.6    mrg <dl compact="compact">
    619  1.6    mrg <dt><code>sh*-*-*</code></dt>
    620  1.6    mrg <dd><p><var>list</var> is a comma separated list of CPU names.  These must be of the
    621  1.1    mrg form <code>sh*</code> or <code>m*</code> (in which case they match the compiler option
    622  1.1    mrg for that processor).  The list should not contain any endian options -
    623  1.6    mrg these are handled by <samp>--with-endian</samp>.
    624  1.6    mrg </p>
    625  1.6    mrg <p>If <var>list</var> is empty, then there will be no multilibs for extra
    626  1.1    mrg processors.  The multilib for the secondary endian remains enabled.
    627  1.6    mrg </p>
    628  1.6    mrg <p>As a special case, if an entry in the list starts with a <code>!</code>
    629  1.6    mrg (exclamation point), then it is added to the list of excluded multilibs.
    630  1.6    mrg Entries of this sort should be compatible with &lsquo;<samp>MULTILIB_EXCLUDES</samp>&rsquo;
    631  1.1    mrg (once the leading <code>!</code> has been stripped).
    632  1.6    mrg </p>
    633  1.6    mrg <p>If <samp>--with-multilib-list</samp> is not given, then a default set of
    634  1.6    mrg multilibs is selected based on the value of <samp>--target</samp>.  This is
    635  1.1    mrg usually the complete set of libraries, but some targets imply a more
    636  1.1    mrg specialized subset.
    637  1.6    mrg </p>
    638  1.6    mrg <p>Example 1: to configure a compiler for SH4A only, but supporting both
    639  1.6    mrg endians, with little endian being the default:
    640  1.6    mrg </p><div class="smallexample">
    641  1.6    mrg <pre class="smallexample">--with-cpu=sh4a --with-endian=little,big --with-multilib-list=
    642  1.6    mrg </pre></div>
    643  1.1    mrg 
    644  1.6    mrg <p>Example 2: to configure a compiler for both SH4A and SH4AL-DSP, but with
    645  1.1    mrg only little endian SH4AL:
    646  1.6    mrg </p><div class="smallexample">
    647  1.6    mrg <pre class="smallexample">--with-cpu=sh4a --with-endian=little,big \
    648  1.6    mrg --with-multilib-list=sh4al,!mb/m4al
    649  1.6    mrg </pre></div>
    650  1.6    mrg 
    651  1.6    mrg </dd>
    652  1.6    mrg <dt><code>x86-64-*-linux*</code></dt>
    653  1.6    mrg <dd><p><var>list</var> is a comma separated list of <code>m32</code>, <code>m64</code> and
    654  1.3  skrll <code>mx32</code> to enable 32-bit, 64-bit and x32 run-time libraries,
    655  1.3  skrll respectively.  If <var>list</var> is empty, then there will be no multilibs
    656  1.3  skrll and only the default run-time library will be enabled.
    657  1.6    mrg </p>
    658  1.6    mrg <p>If <samp>--with-multilib-list</samp> is not given, then only 32-bit and
    659  1.6    mrg 64-bit run-time libraries will be enabled.
    660  1.6    mrg </p></dd>
    661  1.3  skrll </dl>
    662  1.3  skrll 
    663  1.6    mrg </dd>
    664  1.6    mrg <dt><code>--with-endian=<var>endians</var></code></dt>
    665  1.6    mrg <dd><p>Specify what endians to use.
    666  1.1    mrg Currently only implemented for sh*-*-*.
    667  1.6    mrg </p>
    668  1.6    mrg <p><var>endians</var> may be one of the following:
    669  1.6    mrg </p><dl compact="compact">
    670  1.6    mrg <dt><code>big</code></dt>
    671  1.6    mrg <dd><p>Use big endian exclusively.
    672  1.6    mrg </p></dd>
    673  1.6    mrg <dt><code>little</code></dt>
    674  1.6    mrg <dd><p>Use little endian exclusively.
    675  1.6    mrg </p></dd>
    676  1.6    mrg <dt><code>big,little</code></dt>
    677  1.6    mrg <dd><p>Use big endian by default.  Provide a multilib for little endian.
    678  1.6    mrg </p></dd>
    679  1.6    mrg <dt><code>little,big</code></dt>
    680  1.6    mrg <dd><p>Use little endian by default.  Provide a multilib for big endian.
    681  1.6    mrg </p></dd>
    682  1.1    mrg </dl>
    683  1.1    mrg 
    684  1.6    mrg </dd>
    685  1.6    mrg <dt><code>--enable-threads</code></dt>
    686  1.6    mrg <dd><p>Specify that the target
    687  1.1    mrg supports threads.  This affects the Objective-C compiler and runtime
    688  1.6    mrg library, and exception handling for other languages like C++ and Java.
    689  1.1    mrg On some systems, this is the default.
    690  1.6    mrg </p>
    691  1.6    mrg <p>In general, the best (and, in many cases, the only known) threading
    692  1.1    mrg model available will be configured for use.  Beware that on some
    693  1.1    mrg systems, GCC has not been taught what threading models are generally
    694  1.6    mrg available for the system.  In this case, <samp>--enable-threads</samp> is an
    695  1.6    mrg alias for <samp>--enable-threads=single</samp>.
    696  1.6    mrg </p>
    697  1.6    mrg </dd>
    698  1.6    mrg <dt><code>--disable-threads</code></dt>
    699  1.6    mrg <dd><p>Specify that threading support should be disabled for the system.
    700  1.6    mrg This is an alias for <samp>--enable-threads=single</samp>.
    701  1.6    mrg </p>
    702  1.6    mrg </dd>
    703  1.6    mrg <dt><code>--enable-threads=<var>lib</var></code></dt>
    704  1.6    mrg <dd><p>Specify that
    705  1.1    mrg <var>lib</var> is the thread support library.  This affects the Objective-C
    706  1.1    mrg compiler and runtime library, and exception handling for other languages
    707  1.1    mrg like C++ and Java.  The possibilities for <var>lib</var> are:
    708  1.6    mrg </p>
    709  1.6    mrg <dl compact="compact">
    710  1.6    mrg <dt><code>aix</code></dt>
    711  1.6    mrg <dd><p>AIX thread support.
    712  1.6    mrg </p></dd>
    713  1.6    mrg <dt><code>dce</code></dt>
    714  1.6    mrg <dd><p>DCE thread support.
    715  1.6    mrg </p></dd>
    716  1.6    mrg <dt><code>lynx</code></dt>
    717  1.6    mrg <dd><p>LynxOS thread support.
    718  1.6    mrg </p></dd>
    719  1.6    mrg <dt><code>mipssde</code></dt>
    720  1.6    mrg <dd><p>MIPS SDE thread support.
    721  1.6    mrg </p></dd>
    722  1.6    mrg <dt><code>no</code></dt>
    723  1.6    mrg <dd><p>This is an alias for &lsquo;<samp>single</samp>&rsquo;.
    724  1.6    mrg </p></dd>
    725  1.6    mrg <dt><code>posix</code></dt>
    726  1.6    mrg <dd><p>Generic POSIX/Unix98 thread support.
    727  1.6    mrg </p></dd>
    728  1.6    mrg <dt><code>rtems</code></dt>
    729  1.6    mrg <dd><p>RTEMS thread support.
    730  1.6    mrg </p></dd>
    731  1.6    mrg <dt><code>single</code></dt>
    732  1.6    mrg <dd><p>Disable thread support, should work for all platforms.
    733  1.6    mrg </p></dd>
    734  1.6    mrg <dt><code>tpf</code></dt>
    735  1.6    mrg <dd><p>TPF thread support.
    736  1.6    mrg </p></dd>
    737  1.6    mrg <dt><code>vxworks</code></dt>
    738  1.6    mrg <dd><p>VxWorks thread support.
    739  1.6    mrg </p></dd>
    740  1.6    mrg <dt><code>win32</code></dt>
    741  1.6    mrg <dd><p>Microsoft Win32 API thread support.
    742  1.6    mrg </p></dd>
    743  1.1    mrg </dl>
    744  1.1    mrg 
    745  1.6    mrg </dd>
    746  1.6    mrg <dt><code>--enable-tls</code></dt>
    747  1.6    mrg <dd><p>Specify that the target supports TLS (Thread Local Storage).  Usually
    748  1.1    mrg configure can correctly determine if TLS is supported.  In cases where
    749  1.1    mrg it guesses incorrectly, TLS can be explicitly enabled or disabled with
    750  1.6    mrg <samp>--enable-tls</samp> or <samp>--disable-tls</samp>.  This can happen if
    751  1.1    mrg the assembler supports TLS but the C library does not, or if the
    752  1.1    mrg assumptions made by the configure test are incorrect.
    753  1.6    mrg </p>
    754  1.6    mrg </dd>
    755  1.6    mrg <dt><code>--disable-tls</code></dt>
    756  1.6    mrg <dd><p>Specify that the target does not support TLS.
    757  1.6    mrg This is an alias for <samp>--enable-tls=no</samp>.
    758  1.6    mrg </p>
    759  1.6    mrg </dd>
    760  1.6    mrg <dt><code>--with-cpu=<var>cpu</var></code></dt>
    761  1.6    mrg <dt><code>--with-cpu-32=<var>cpu</var></code></dt>
    762  1.6    mrg <dt><code>--with-cpu-64=<var>cpu</var></code></dt>
    763  1.6    mrg <dd><p>Specify which cpu variant the compiler should generate code for by default.
    764  1.6    mrg <var>cpu</var> will be used as the default value of the <samp>-mcpu=</samp> switch.
    765  1.5    mrg This option is only supported on some targets, including ARC, ARM, i386, M68k,
    766  1.6    mrg PowerPC, and SPARC.  It is mandatory for ARC.  The <samp>--with-cpu-32</samp> and
    767  1.6    mrg <samp>--with-cpu-64</samp> options specify separate default CPUs for
    768  1.1    mrg 32-bit and 64-bit modes; these options are only supported for i386,
    769  1.1    mrg x86-64 and PowerPC.
    770  1.6    mrg </p>
    771  1.6    mrg </dd>
    772  1.6    mrg <dt><code>--with-schedule=<var>cpu</var></code></dt>
    773  1.6    mrg <dt><code>--with-arch=<var>cpu</var></code></dt>
    774  1.6    mrg <dt><code>--with-arch-32=<var>cpu</var></code></dt>
    775  1.6    mrg <dt><code>--with-arch-64=<var>cpu</var></code></dt>
    776  1.6    mrg <dt><code>--with-tune=<var>cpu</var></code></dt>
    777  1.6    mrg <dt><code>--with-tune-32=<var>cpu</var></code></dt>
    778  1.6    mrg <dt><code>--with-tune-64=<var>cpu</var></code></dt>
    779  1.6    mrg <dt><code>--with-abi=<var>abi</var></code></dt>
    780  1.6    mrg <dt><code>--with-fpu=<var>type</var></code></dt>
    781  1.6    mrg <dt><code>--with-float=<var>type</var></code></dt>
    782  1.6    mrg <dd><p>These configure options provide default values for the <samp>-mschedule=</samp>,
    783  1.6    mrg <samp>-march=</samp>, <samp>-mtune=</samp>, <samp>-mabi=</samp>, and <samp>-mfpu=</samp>
    784  1.6    mrg options and for <samp>-mhard-float</samp> or <samp>-msoft-float</samp>.  As with
    785  1.6    mrg <samp>--with-cpu</samp>, which switches will be accepted and acceptable values
    786  1.1    mrg of the arguments depend on the target.
    787  1.6    mrg </p>
    788  1.6    mrg </dd>
    789  1.6    mrg <dt><code>--with-mode=<var>mode</var></code></dt>
    790  1.6    mrg <dd><p>Specify if the compiler should default to <samp>-marm</samp> or <samp>-mthumb</samp>.
    791  1.1    mrg This option is only supported on ARM targets.
    792  1.6    mrg </p>
    793  1.6    mrg </dd>
    794  1.6    mrg <dt><code>--with-stack-offset=<var>num</var></code></dt>
    795  1.6    mrg <dd><p>This option sets the default for the -mstack-offset=<var>num</var> option,
    796  1.3  skrll and will thus generally also control the setting of this option for
    797  1.3  skrll libraries.  This option is only supported on Epiphany targets.
    798  1.6    mrg </p>
    799  1.6    mrg </dd>
    800  1.6    mrg <dt><code>--with-fpmath=<var>isa</var></code></dt>
    801  1.6    mrg <dd><p>This options sets <samp>-mfpmath=sse</samp> by default and specifies the default
    802  1.6    mrg ISA for floating-point arithmetics.  You can select either &lsquo;<samp>sse</samp>&rsquo; which
    803  1.6    mrg enables <samp>-msse2</samp> or &lsquo;<samp>avx</samp>&rsquo; which enables <samp>-mavx</samp> by default.
    804  1.3  skrll This option is only supported on i386 and x86-64 targets.
    805  1.6    mrg </p>
    806  1.6    mrg </dd>
    807  1.6    mrg <dt><code>--with-fp-32=<var>mode</var></code></dt>
    808  1.6    mrg <dd><p>On MIPS targets, set the default value for the <samp>-mfp</samp> option when using
    809  1.5    mrg the o32 ABI.  The possibilities for <var>mode</var> are:
    810  1.6    mrg </p><dl compact="compact">
    811  1.6    mrg <dt><code>32</code></dt>
    812  1.6    mrg <dd><p>Use the o32 FP32 ABI extension, as with the <samp>-mfp32</samp> command-line
    813  1.6    mrg option.
    814  1.6    mrg </p></dd>
    815  1.6    mrg <dt><code>xx</code></dt>
    816  1.6    mrg <dd><p>Use the o32 FPXX ABI extension, as with the <samp>-mfpxx</samp> command-line
    817  1.6    mrg option.
    818  1.6    mrg </p></dd>
    819  1.6    mrg <dt><code>64</code></dt>
    820  1.6    mrg <dd><p>Use the o32 FP64 ABI extension, as with the <samp>-mfp64</samp> command-line
    821  1.6    mrg option.
    822  1.6    mrg </p></dd>
    823  1.5    mrg </dl>
    824  1.6    mrg <p>In the absence of this configuration option the default is to use the o32
    825  1.5    mrg FP32 ABI extension.
    826  1.6    mrg </p>
    827  1.6    mrg </dd>
    828  1.6    mrg <dt><code>--with-odd-spreg-32</code></dt>
    829  1.6    mrg <dd><p>On MIPS targets, set the <samp>-modd-spreg</samp> option by default when using
    830  1.5    mrg the o32 ABI.
    831  1.6    mrg </p>
    832  1.6    mrg </dd>
    833  1.6    mrg <dt><code>--without-odd-spreg-32</code></dt>
    834  1.6    mrg <dd><p>On MIPS targets, set the <samp>-mno-odd-spreg</samp> option by default when using
    835  1.5    mrg the o32 ABI.  This is normally used in conjunction with
    836  1.6    mrg <samp>--with-fp-32=64</samp> in order to target the o32 FP64A ABI extension.
    837  1.6    mrg </p>
    838  1.6    mrg </dd>
    839  1.6    mrg <dt><code>--with-nan=<var>encoding</var></code></dt>
    840  1.6    mrg <dd><p>On MIPS targets, set the default encoding convention to use for the
    841  1.5    mrg special not-a-number (NaN) IEEE 754 floating-point data.  The
    842  1.5    mrg possibilities for <var>encoding</var> are:
    843  1.6    mrg </p><dl compact="compact">
    844  1.6    mrg <dt><code>legacy</code></dt>
    845  1.6    mrg <dd><p>Use the legacy encoding, as with the <samp>-mnan=legacy</samp> command-line
    846  1.6    mrg option.
    847  1.6    mrg </p></dd>
    848  1.6    mrg <dt><code>2008</code></dt>
    849  1.6    mrg <dd><p>Use the 754-2008 encoding, as with the <samp>-mnan=2008</samp> command-line
    850  1.6    mrg option.
    851  1.6    mrg </p></dd>
    852  1.5    mrg </dl>
    853  1.6    mrg <p>To use this configuration option you must have an assembler version
    854  1.6    mrg installed that supports the <samp>-mnan=</samp> command-line option too.
    855  1.5    mrg In the absence of this configuration option the default convention is
    856  1.6    mrg the legacy encoding, as when neither of the <samp>-mnan=2008</samp> and
    857  1.6    mrg <samp>-mnan=legacy</samp> command-line options has been used.
    858  1.6    mrg </p>
    859  1.6    mrg </dd>
    860  1.6    mrg <dt><code>--with-divide=<var>type</var></code></dt>
    861  1.6    mrg <dd><p>Specify how the compiler should generate code for checking for
    862  1.6    mrg division by zero.  This option is only supported on the MIPS target.
    863  1.1    mrg The possibilities for <var>type</var> are:
    864  1.6    mrg </p><dl compact="compact">
    865  1.6    mrg <dt><code>traps</code></dt>
    866  1.6    mrg <dd><p>Division by zero checks use conditional traps (this is the default on
    867  1.6    mrg systems that support conditional traps).
    868  1.6    mrg </p></dd>
    869  1.6    mrg <dt><code>breaks</code></dt>
    870  1.6    mrg <dd><p>Division by zero checks use the break instruction.
    871  1.6    mrg </p></dd>
    872  1.1    mrg </dl>
    873  1.1    mrg 
    874  1.6    mrg 
    875  1.6    mrg </dd>
    876  1.6    mrg <dt><code>--with-llsc</code></dt>
    877  1.6    mrg <dd><p>On MIPS targets, make <samp>-mllsc</samp> the default when no
    878  1.6    mrg <samp>-mno-llsc</samp> option is passed.  This is the default for
    879  1.1    mrg Linux-based targets, as the kernel will emulate them if the ISA does
    880  1.1    mrg not provide them.
    881  1.6    mrg </p>
    882  1.6    mrg </dd>
    883  1.6    mrg <dt><code>--without-llsc</code></dt>
    884  1.6    mrg <dd><p>On MIPS targets, make <samp>-mno-llsc</samp> the default when no
    885  1.6    mrg <samp>-mllsc</samp> option is passed.
    886  1.6    mrg </p>
    887  1.6    mrg </dd>
    888  1.6    mrg <dt><code>--with-synci</code></dt>
    889  1.6    mrg <dd><p>On MIPS targets, make <samp>-msynci</samp> the default when no
    890  1.6    mrg <samp>-mno-synci</samp> option is passed.
    891  1.6    mrg </p>
    892  1.6    mrg </dd>
    893  1.6    mrg <dt><code>--without-synci</code></dt>
    894  1.6    mrg <dd><p>On MIPS targets, make <samp>-mno-synci</samp> the default when no
    895  1.6    mrg <samp>-msynci</samp> option is passed.  This is the default.
    896  1.6    mrg </p>
    897  1.6    mrg </dd>
    898  1.6    mrg <dt><code>--with-mips-plt</code></dt>
    899  1.6    mrg <dd><p>On MIPS targets, make use of copy relocations and PLTs.
    900  1.1    mrg These features are extensions to the traditional
    901  1.1    mrg SVR4-based MIPS ABIs and require support from GNU binutils
    902  1.1    mrg and the runtime C library.
    903  1.6    mrg </p>
    904  1.6    mrg </dd>
    905  1.6    mrg <dt><code>--enable-__cxa_atexit</code></dt>
    906  1.6    mrg <dd><p>Define if you want to use __cxa_atexit, rather than atexit, to
    907  1.6    mrg register C++ destructors for local statics and global objects.
    908  1.1    mrg This is essential for fully standards-compliant handling of
    909  1.1    mrg destructors, but requires __cxa_atexit in libc.  This option is currently
    910  1.1    mrg only available on systems with GNU libc.  When enabled, this will cause
    911  1.6    mrg <samp>-fuse-cxa-atexit</samp> to be passed by default.
    912  1.6    mrg </p>
    913  1.6    mrg </dd>
    914  1.6    mrg <dt><code>--enable-gnu-indirect-function</code></dt>
    915  1.6    mrg <dd><p>Define if you want to enable the <code>ifunc</code> attribute.  This option is
    916  1.3  skrll currently only available on systems with GNU libc on certain targets.
    917  1.6    mrg </p>
    918  1.6    mrg </dd>
    919  1.6    mrg <dt><code>--enable-target-optspace</code></dt>
    920  1.6    mrg <dd><p>Specify that target
    921  1.6    mrg libraries should be optimized for code space instead of code speed.
    922  1.1    mrg This is the default for the m32r platform.
    923  1.6    mrg </p>
    924  1.6    mrg </dd>
    925  1.6    mrg <dt><code>--with-cpp-install-dir=<var>dirname</var></code></dt>
    926  1.6    mrg <dd><p>Specify that the user visible <code>cpp</code> program should be installed
    927  1.6    mrg in <samp><var>prefix</var>/<var>dirname</var>/cpp</samp>, in addition to <var>bindir</var>.
    928  1.6    mrg </p>
    929  1.6    mrg </dd>
    930  1.6    mrg <dt><code>--enable-comdat</code></dt>
    931  1.6    mrg <dd><p>Enable COMDAT group support.  This is primarily used to override the
    932  1.1    mrg automatically detected value.
    933  1.6    mrg </p>
    934  1.6    mrg </dd>
    935  1.6    mrg <dt><code>--enable-initfini-array</code></dt>
    936  1.6    mrg <dd><p>Force the use of sections <code>.init_array</code> and <code>.fini_array</code>
    937  1.1    mrg (instead of <code>.init</code> and <code>.fini</code>) for constructors and
    938  1.6    mrg destructors.  Option <samp>--disable-initfini-array</samp> has the
    939  1.1    mrg opposite effect.  If neither option is specified, the configure script
    940  1.1    mrg will try to guess whether the <code>.init_array</code> and
    941  1.1    mrg <code>.fini_array</code> sections are supported and, if they are, use them.
    942  1.6    mrg </p>
    943  1.6    mrg </dd>
    944  1.6    mrg <dt><code>--enable-link-mutex</code></dt>
    945  1.6    mrg <dd><p>When building GCC, use a mutex to avoid linking the compilers for
    946  1.5    mrg multiple languages at the same time, to avoid thrashing on build
    947  1.5    mrg systems with limited free memory.  The default is not to use such a mutex.
    948  1.6    mrg </p>
    949  1.6    mrg </dd>
    950  1.6    mrg <dt><code>--enable-maintainer-mode</code></dt>
    951  1.6    mrg <dd><p>The build rules that regenerate the Autoconf and Automake output files as
    952  1.6    mrg well as the GCC master message catalog <samp>gcc.pot</samp> are normally
    953  1.1    mrg disabled.  This is because it can only be rebuilt if the complete source
    954  1.1    mrg tree is present.  If you have changed the sources and want to rebuild the
    955  1.6    mrg catalog, configuring with <samp>--enable-maintainer-mode</samp> will enable
    956  1.1    mrg this.  Note that you need a recent version of the <code>gettext</code> tools
    957  1.1    mrg to do so.
    958  1.6    mrg </p>
    959  1.6    mrg </dd>
    960  1.6    mrg <dt><code>--disable-bootstrap</code></dt>
    961  1.6    mrg <dd><p>For a native build, the default configuration is to perform
    962  1.6    mrg a 3-stage bootstrap of the compiler when &lsquo;<samp>make</samp>&rsquo; is invoked,
    963  1.1    mrg testing that GCC can compile itself correctly.  If you want to disable
    964  1.6    mrg this process, you can configure with <samp>--disable-bootstrap</samp>.
    965  1.6    mrg </p>
    966  1.6    mrg </dd>
    967  1.6    mrg <dt><code>--enable-bootstrap</code></dt>
    968  1.6    mrg <dd><p>In special cases, you may want to perform a 3-stage build
    969  1.6    mrg even if the target and host triplets are different.
    970  1.1    mrg This is possible when the host can run code compiled for
    971  1.6    mrg the target (e.g. host is i686-linux, target is i486-linux).
    972  1.1    mrg Starting from GCC 4.2, to do this you have to configure explicitly
    973  1.6    mrg with <samp>--enable-bootstrap</samp>.
    974  1.6    mrg </p>
    975  1.6    mrg </dd>
    976  1.6    mrg <dt><code>--enable-generated-files-in-srcdir</code></dt>
    977  1.6    mrg <dd><p>Neither the .c and .h files that are generated from Bison and flex nor the
    978  1.1    mrg info manuals and man pages that are built from the .texi files are present
    979  1.1    mrg in the SVN development tree.  When building GCC from that development tree,
    980  1.1    mrg or from one of our snapshots, those generated files are placed in your
    981  1.1    mrg build directory, which allows for the source to be in a readonly
    982  1.1    mrg directory.
    983  1.6    mrg </p>
    984  1.6    mrg <p>If you configure with <samp>--enable-generated-files-in-srcdir</samp> then those
    985  1.1    mrg generated files will go into the source directory.  This is mainly intended
    986  1.1    mrg for generating release or prerelease tarballs of the GCC sources, since it
    987  1.1    mrg is not a requirement that the users of source releases to have flex, Bison,
    988  1.1    mrg or makeinfo.
    989  1.6    mrg </p>
    990  1.6    mrg </dd>
    991  1.6    mrg <dt><code>--enable-version-specific-runtime-libs</code></dt>
    992  1.6    mrg <dd><p>Specify
    993  1.1    mrg that runtime libraries should be installed in the compiler specific
    994  1.6    mrg subdirectory (<samp><var>libdir</var>/gcc</samp>) rather than the usual places.  In
    995  1.6    mrg addition, &lsquo;<samp>libstdc++</samp>&rsquo;&rsquo;s include files will be installed into
    996  1.1    mrg <samp><var>libdir</var></samp> unless you overruled it by using
    997  1.6    mrg <samp>--with-gxx-include-dir=<var>dirname</var></samp>.  Using this option is
    998  1.1    mrg particularly useful if you intend to use several versions of GCC in
    999  1.6    mrg parallel.  This is currently supported by &lsquo;<samp>libgfortran</samp>&rsquo;,
   1000  1.6    mrg &lsquo;<samp>libjava</samp>&rsquo;, &lsquo;<samp>libstdc++</samp>&rsquo;, and &lsquo;<samp>libobjc</samp>&rsquo;.
   1001  1.6    mrg </p>
   1002  1.6    mrg </dd>
   1003  1.6    mrg <dt><code><a name="WithAixSoname"></a>--with-aix-soname=&lsquo;<samp>aix</samp>&rsquo;, &lsquo;<samp>svr4</samp>&rsquo; or &lsquo;<samp>both</samp>&rsquo;</code></dt>
   1004  1.6    mrg <dd><p>Traditional AIX shared library versioning (versioned <code>Shared Object</code>
   1005  1.5    mrg files as members of unversioned <code>Archive Library</code> files named
   1006  1.6    mrg &lsquo;<samp>lib.a</samp>&rsquo;) causes numerous headaches for package managers. However,
   1007  1.5    mrg <code>Import Files</code> as members of <code>Archive Library</code> files allow for
   1008  1.5    mrg <strong>filename-based versioning</strong> of shared libraries as seen on Linux/SVR4,
   1009  1.6    mrg where this is called the &quot;SONAME&quot;. But as they prevent static linking,
   1010  1.5    mrg <code>Import Files</code> may be used with <code>Runtime Linking</code> only, where the
   1011  1.6    mrg linker does search for &lsquo;<samp>libNAME.so</samp>&rsquo; before &lsquo;<samp>libNAME.a</samp>&rsquo; library
   1012  1.6    mrg filenames with the &lsquo;<samp>-lNAME</samp>&rsquo; linker flag.
   1013  1.6    mrg </p>
   1014  1.6    mrg <a name="AixLdCommand"></a><p>For detailed information please refer to the AIX
   1015  1.6    mrg <a href="http://www-01.ibm.com/support/knowledgecenter/search/%22the%20ld%20command%2C%20also%20called%20the%20linkage%20editor%20or%20binder%22">ld
   1016  1.6    mrg Command</a> reference.
   1017  1.6    mrg </p>
   1018  1.6    mrg <p>As long as shared library creation is enabled, upon:
   1019  1.6    mrg </p><dl compact="compact">
   1020  1.6    mrg <dt><code>--with-aix-soname=aix</code></dt>
   1021  1.6    mrg <dt><code>--with-aix-soname=both</code></dt>
   1022  1.6    mrg <dd><p>A (traditional AIX) <code>Shared Archive Library</code> file is created:
   1023  1.6    mrg  </p><ul>
   1024  1.6    mrg <li> using the &lsquo;<samp>libNAME.a</samp>&rsquo; filename scheme
   1025  1.6    mrg   </li><li> with the <code>Shared Object</code> file as archive member named
   1026  1.6    mrg   &lsquo;<samp>libNAME.so.V</samp>&rsquo; (except for &lsquo;<samp>libgcc_s</samp>&rsquo;, where the <code>Shared
   1027  1.6    mrg   Object</code> file is named &lsquo;<samp>shr.o</samp>&rsquo; for backwards compatibility), which
   1028  1.6    mrg   <ul class="no-bullet">
   1029  1.6    mrg <li>- is used for runtime loading from inside the &lsquo;<samp>libNAME.a</samp>&rsquo; file
   1030  1.6    mrg    </li><li>- is used for dynamic loading via
   1031  1.6    mrg    <code>dlopen(&quot;libNAME.a(libNAME.so.V)&quot;, RTLD_MEMBER)</code>
   1032  1.6    mrg    </li><li>- is used for shared linking
   1033  1.6    mrg    </li><li>- is used for static linking, so no separate <code>Static Archive
   1034  1.5    mrg    Library</code> file is needed
   1035  1.6    mrg   </li></ul>
   1036  1.6    mrg </li></ul>
   1037  1.6    mrg </dd>
   1038  1.6    mrg <dt><code>--with-aix-soname=both</code></dt>
   1039  1.6    mrg <dt><code>--with-aix-soname=svr4</code></dt>
   1040  1.6    mrg <dd><p>A (second) <code>Shared Archive Library</code> file is created:
   1041  1.6    mrg  </p><ul>
   1042  1.6    mrg <li> using the &lsquo;<samp>libNAME.so.V</samp>&rsquo; filename scheme
   1043  1.6    mrg  </li><li> with the <code>Shared Object</code> file as archive member named
   1044  1.6    mrg  &lsquo;<samp>shr.o</samp>&rsquo;, which
   1045  1.6    mrg   <ul class="no-bullet">
   1046  1.6    mrg <li>- is created with the <code>-G linker flag</code>
   1047  1.6    mrg    </li><li>- has the <code>F_LOADONLY</code> flag set
   1048  1.6    mrg    </li><li>- is used for runtime loading from inside the &lsquo;<samp>libNAME.so.V</samp>&rsquo; file
   1049  1.6    mrg    </li><li>- is used for dynamic loading via <code>dlopen(&quot;libNAME.so.V(shr.o)&quot;,
   1050  1.5    mrg    RTLD_MEMBER)</code>
   1051  1.6    mrg   </li></ul>
   1052  1.6    mrg </li><li> with the <code>Import File</code> as archive member named &lsquo;<samp>shr.imp</samp>&rsquo;,
   1053  1.5    mrg  which
   1054  1.6    mrg   <ul class="no-bullet">
   1055  1.6    mrg <li>- refers to &lsquo;<samp>libNAME.so.V(shr.o)</samp>&rsquo; as the &quot;SONAME&quot;, to be recorded
   1056  1.5    mrg    in the <code>Loader Section</code> of subsequent binaries
   1057  1.6    mrg    </li><li>- indicates whether &lsquo;<samp>libNAME.so.V(shr.o)</samp>&rsquo; is 32 or 64 bit
   1058  1.6    mrg    </li><li>- lists all the public symbols exported by &lsquo;<samp>lib.so.V(shr.o)</samp>&rsquo;,
   1059  1.6    mrg    eventually decorated with the <code>&lsquo;<samp>weak</samp>&rsquo; Keyword</code>
   1060  1.6    mrg    </li><li>- is necessary for shared linking against &lsquo;<samp>lib.so.V(shr.o)</samp>&rsquo;
   1061  1.6    mrg    </li></ul>
   1062  1.6    mrg </li></ul>
   1063  1.6    mrg <p>A symbolic link using the &lsquo;<samp>libNAME.so</samp>&rsquo; filename scheme is created:
   1064  1.6    mrg   </p><ul>
   1065  1.6    mrg <li> pointing to the &lsquo;<samp>libNAME.so.V</samp>&rsquo; <code>Shared Archive Library</code> file
   1066  1.6    mrg   </li><li> to permit the <code>ld Command</code> to find &lsquo;<samp>lib.so.V(shr.imp)</samp>&rsquo; via
   1067  1.6    mrg   the &lsquo;<samp>-lNAME</samp>&rsquo; argument (requires <code>Runtime Linking</code> to be enabled)
   1068  1.6    mrg   </li><li> to permit dynamic loading of &lsquo;<samp>lib.so.V(shr.o)</samp>&rsquo; without the need
   1069  1.6    mrg   to specify the version number via <code>dlopen(&quot;libNAME.so(shr.o)&quot;,
   1070  1.5    mrg   RTLD_MEMBER)</code>
   1071  1.6    mrg   </li></ul>
   1072  1.6    mrg </dd>
   1073  1.6    mrg </dl>
   1074  1.5    mrg 
   1075  1.6    mrg <p>As long as static library creation is enabled, upon:
   1076  1.6    mrg </p><dl compact="compact">
   1077  1.6    mrg <dt><code>--with-aix-soname=svr4</code></dt>
   1078  1.6    mrg <dd><p>A <code>Static Archive Library</code> is created:
   1079  1.6    mrg  </p><ul>
   1080  1.6    mrg <li> using the &lsquo;<samp>libNAME.a</samp>&rsquo; filename scheme
   1081  1.6    mrg  </li><li> with all the <code>Static Object</code> files as archive members, which
   1082  1.6    mrg   <ul class="no-bullet">
   1083  1.6    mrg <li>- are used for static linking
   1084  1.6    mrg   </li></ul>
   1085  1.6    mrg </li></ul>
   1086  1.6    mrg </dd>
   1087  1.6    mrg </dl>
   1088  1.5    mrg 
   1089  1.6    mrg <p>While the aix-soname=&lsquo;<samp>svr4</samp>&rsquo; option does not create <code>Shared Object</code>
   1090  1.5    mrg files as members of unversioned <code>Archive Library</code> files any more, package
   1091  1.5    mrg managers still are responsible to
   1092  1.5    mrg <a href="./specific.html#TransferAixShobj">transfer</a> <code>Shared Object</code> files
   1093  1.5    mrg found as member of a previously installed unversioned <code>Archive Library</code>
   1094  1.5    mrg file into the newly installed <code>Archive Library</code> file with the same
   1095  1.5    mrg filename.
   1096  1.6    mrg </p>
   1097  1.6    mrg <p><em>WARNING:</em> Creating <code>Shared Object</code> files with <code>Runtime Linking</code>
   1098  1.5    mrg enabled may bloat the TOC, eventually leading to <code>TOC overflow</code> errors,
   1099  1.6    mrg requiring the use of either the <samp>-Wl,-bbigtoc</samp> linker flag (seen to
   1100  1.5    mrg break with the <code>GDB</code> debugger) or some of the TOC-related compiler flags,
   1101  1.5    mrg see &ldquo;RS/6000 and PowerPC Options&rdquo; in the main manual.
   1102  1.6    mrg </p>
   1103  1.6    mrg <p><samp>--with-aix-soname</samp> is currently supported by &lsquo;<samp>libgcc_s</samp>&rsquo; only, so
   1104  1.5    mrg this option is still experimental and not for normal use yet.
   1105  1.6    mrg </p>
   1106  1.6    mrg <p>Default is the traditional behaviour <samp>--with-aix-soname=&lsquo;<samp>aix</samp>&rsquo;</samp>.
   1107  1.6    mrg </p>
   1108  1.6    mrg </dd>
   1109  1.6    mrg <dt><code>--enable-languages=<var>lang1</var>,<var>lang2</var>,&hellip;</code></dt>
   1110  1.6    mrg <dd><p>Specify that only a particular subset of compilers and
   1111  1.1    mrg their runtime libraries should be built.  For a list of valid values for
   1112  1.1    mrg <var>langN</var> you can issue the following command in the
   1113  1.6    mrg <samp>gcc</samp> directory of your GCC source tree:<br>
   1114  1.6    mrg </p><div class="smallexample">
   1115  1.6    mrg <pre class="smallexample">grep language= */config-lang.in
   1116  1.6    mrg </pre></div>
   1117  1.6    mrg <p>Currently, you can use any of the following:
   1118  1.3  skrll <code>all</code>, <code>ada</code>, <code>c</code>, <code>c++</code>, <code>fortran</code>,
   1119  1.6    mrg <code>go</code>, <code>java</code>, <code>objc</code>, <code>obj-c++</code>.
   1120  1.6    mrg Building the Ada compiler has special requirements, see below.
   1121  1.1    mrg If you do not pass this flag, or specify the option <code>all</code>, then all
   1122  1.6    mrg default languages available in the <samp>gcc</samp> sub-tree will be configured.
   1123  1.3  skrll Ada, Go and Objective-C++ are not default languages; the rest are.
   1124  1.6    mrg </p>
   1125  1.6    mrg </dd>
   1126  1.6    mrg <dt><code>--enable-stage1-languages=<var>lang1</var>,<var>lang2</var>,&hellip;</code></dt>
   1127  1.6    mrg <dd><p>Specify that a particular subset of compilers and their runtime
   1128  1.1    mrg libraries should be built with the system C compiler during stage 1 of
   1129  1.1    mrg the bootstrap process, rather than only in later stages with the
   1130  1.1    mrg bootstrapped C compiler.  The list of valid values is the same as for
   1131  1.6    mrg <samp>--enable-languages</samp>, and the option <code>all</code> will select all
   1132  1.6    mrg of the languages enabled by <samp>--enable-languages</samp>.  This option is
   1133  1.1    mrg primarily useful for GCC development; for instance, when a development
   1134  1.1    mrg version of the compiler cannot bootstrap due to compiler bugs, or when
   1135  1.1    mrg one is debugging front ends other than the C front end.  When this
   1136  1.1    mrg option is used, one can then build the target libraries for the
   1137  1.6    mrg specified languages with the stage-1 compiler by using <code>make
   1138  1.6    mrg stage1-bubble all-target</code>, or run the testsuite on the stage-1 compiler
   1139  1.6    mrg for the specified languages using <code>make stage1-start check-gcc</code>.
   1140  1.6    mrg </p>
   1141  1.6    mrg </dd>
   1142  1.6    mrg <dt><code>--disable-libada</code></dt>
   1143  1.6    mrg <dd><p>Specify that the run-time libraries and tools used by GNAT should not
   1144  1.1    mrg be built.  This can be useful for debugging, or for compatibility with
   1145  1.1    mrg previous Ada build procedures, when it was required to explicitly
   1146  1.6    mrg do a &lsquo;<samp>make -C gcc gnatlib_and_tools</samp>&rsquo;.
   1147  1.6    mrg </p>
   1148  1.6    mrg </dd>
   1149  1.6    mrg <dt><code>--disable-libsanitizer</code></dt>
   1150  1.6    mrg <dd><p>Specify that the run-time libraries for the various sanitizers should
   1151  1.5    mrg not be built.
   1152  1.6    mrg </p>
   1153  1.6    mrg </dd>
   1154  1.6    mrg <dt><code>--disable-libssp</code></dt>
   1155  1.6    mrg <dd><p>Specify that the run-time libraries for stack smashing protection
   1156  1.1    mrg should not be built.
   1157  1.6    mrg </p>
   1158  1.6    mrg </dd>
   1159  1.6    mrg <dt><code>--disable-libquadmath</code></dt>
   1160  1.6    mrg <dd><p>Specify that the GCC quad-precision math library should not be built.
   1161  1.3  skrll On some systems, the library is required to be linkable when building
   1162  1.6    mrg the Fortran front end, unless <samp>--disable-libquadmath-support</samp>
   1163  1.3  skrll is used.
   1164  1.6    mrg </p>
   1165  1.6    mrg </dd>
   1166  1.6    mrg <dt><code>--disable-libquadmath-support</code></dt>
   1167  1.6    mrg <dd><p>Specify that the Fortran front end and <code>libgfortran</code> do not add
   1168  1.3  skrll support for <code>libquadmath</code> on systems supporting it.
   1169  1.6    mrg </p>
   1170  1.6    mrg </dd>
   1171  1.6    mrg <dt><code>--disable-libgomp</code></dt>
   1172  1.6    mrg <dd><p>Specify that the GNU Offloading and Multi Processing Runtime Library
   1173  1.5    mrg should not be built.
   1174  1.6    mrg </p>
   1175  1.6    mrg </dd>
   1176  1.6    mrg <dt><code>--disable-libvtv</code></dt>
   1177  1.6    mrg <dd><p>Specify that the run-time libraries used by vtable verification
   1178  1.5    mrg should not be built.
   1179  1.6    mrg </p>
   1180  1.6    mrg </dd>
   1181  1.6    mrg <dt><code>--with-dwarf2</code></dt>
   1182  1.6    mrg <dd><p>Specify that the compiler should
   1183  1.1    mrg use DWARF 2 debugging information as the default.
   1184  1.6    mrg </p>
   1185  1.6    mrg </dd>
   1186  1.6    mrg <dt><code>--enable-targets=all</code></dt>
   1187  1.6    mrg <dt><code>--enable-targets=<var>target_list</var></code></dt>
   1188  1.6    mrg <dd><p>Some GCC targets, e.g. powerpc64-linux, build bi-arch compilers.
   1189  1.1    mrg These are compilers that are able to generate either 64-bit or 32-bit
   1190  1.6    mrg code.  Typically, the corresponding 32-bit target, e.g.
   1191  1.1    mrg powerpc-linux for powerpc64-linux, only generates 32-bit code.  This
   1192  1.1    mrg option enables the 32-bit target to be a bi-arch compiler, which is
   1193  1.1    mrg useful when you want a bi-arch compiler that defaults to 32-bit, and
   1194  1.6    mrg you are building a bi-arch or multi-arch binutils in a combined tree.
   1195  1.1    mrg On mips-linux, this will build a tri-arch compiler (ABI o32/n32/64),
   1196  1.6    mrg defaulted to o32.
   1197  1.3  skrll Currently, this option only affects sparc-linux, powerpc-linux, x86-linux,
   1198  1.3  skrll mips-linux and s390-linux.
   1199  1.6    mrg </p>
   1200  1.6    mrg </dd>
   1201  1.6    mrg <dt><code>--enable-secureplt</code></dt>
   1202  1.6    mrg <dd><p>This option enables <samp>-msecure-plt</samp> by default for powerpc-linux.
   1203  1.1    mrg See &ldquo;RS/6000 and PowerPC Options&rdquo; in the main manual
   1204  1.6    mrg </p>
   1205  1.6    mrg </dd>
   1206  1.6    mrg <dt><code>--enable-cld</code></dt>
   1207  1.6    mrg <dd><p>This option enables <samp>-mcld</samp> by default for 32-bit x86 targets.
   1208  1.1    mrg See &ldquo;i386 and x86-64 Options&rdquo; in the main manual
   1209  1.6    mrg </p>
   1210  1.6    mrg </dd>
   1211  1.6    mrg <dt><code>--enable-win32-registry</code></dt>
   1212  1.6    mrg <dt><code>--enable-win32-registry=<var>key</var></code></dt>
   1213  1.6    mrg <dt><code>--disable-win32-registry</code></dt>
   1214  1.6    mrg <dd><p>The <samp>--enable-win32-registry</samp> option enables Microsoft Windows-hosted GCC
   1215  1.1    mrg to look up installations paths in the registry using the following key:
   1216  1.6    mrg </p>
   1217  1.6    mrg <div class="smallexample">
   1218  1.6    mrg <pre class="smallexample"><code>HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\<var>key</var></code>
   1219  1.6    mrg </pre></div>
   1220  1.1    mrg 
   1221  1.6    mrg <p><var>key</var> defaults to GCC version number, and can be overridden by the
   1222  1.6    mrg <samp>--enable-win32-registry=<var>key</var></samp> option.  Vendors and distributors
   1223  1.1    mrg who use custom installers are encouraged to provide a different key,
   1224  1.1    mrg perhaps one comprised of vendor name and GCC version number, to
   1225  1.1    mrg avoid conflict with existing installations.  This feature is enabled
   1226  1.6    mrg by default, and can be disabled by <samp>--disable-win32-registry</samp>
   1227  1.1    mrg option.  This option has no effect on the other hosts.
   1228  1.6    mrg </p>
   1229  1.6    mrg </dd>
   1230  1.6    mrg <dt><code>--nfp</code></dt>
   1231  1.6    mrg <dd><p>Specify that the machine does not have a floating point unit.  This
   1232  1.6    mrg option only applies to &lsquo;<samp>m68k-sun-sunos<var>n</var></samp>&rsquo;.  On any other
   1233  1.6    mrg system, <samp>--nfp</samp> has no effect.
   1234  1.6    mrg </p>
   1235  1.6    mrg </dd>
   1236  1.6    mrg <dt><code>--enable-werror</code></dt>
   1237  1.6    mrg <dt><code>--disable-werror</code></dt>
   1238  1.6    mrg <dt><code>--enable-werror=yes</code></dt>
   1239  1.6    mrg <dt><code>--enable-werror=no</code></dt>
   1240  1.6    mrg <dd><p>When you specify this option, it controls whether certain files in the
   1241  1.6    mrg compiler are built with <samp>-Werror</samp> in bootstrap stage2 and later.
   1242  1.6    mrg If you don&rsquo;t specify it, <samp>-Werror</samp> is turned on for the main
   1243  1.1    mrg development trunk.  However it defaults to off for release branches and
   1244  1.6    mrg final releases.  The specific files which get <samp>-Werror</samp> are
   1245  1.1    mrg controlled by the Makefiles.
   1246  1.6    mrg </p>
   1247  1.6    mrg </dd>
   1248  1.6    mrg <dt><code>--enable-checking</code></dt>
   1249  1.6    mrg <dt><code>--enable-checking=<var>list</var></code></dt>
   1250  1.6    mrg <dd><p>When you specify this option, the compiler is built to perform internal
   1251  1.1    mrg consistency checks of the requested complexity.  This does not change the
   1252  1.1    mrg generated code, but adds error checking within the compiler.  This will
   1253  1.1    mrg slow down the compiler and may only work properly if you are building
   1254  1.6    mrg the compiler with GCC.  This is &lsquo;<samp>yes</samp>&rsquo; by default when building
   1255  1.6    mrg from SVN or snapshots, but &lsquo;<samp>release</samp>&rsquo; for releases.  The default
   1256  1.6    mrg for building the stage1 compiler is &lsquo;<samp>yes</samp>&rsquo;.  More control
   1257  1.1    mrg over the checks may be had by specifying <var>list</var>.  The categories of
   1258  1.6    mrg checks available are &lsquo;<samp>yes</samp>&rsquo; (most common checks
   1259  1.6    mrg &lsquo;<samp>assert,misc,tree,gc,rtlflag,runtime</samp>&rsquo;), &lsquo;<samp>no</samp>&rsquo; (no checks at
   1260  1.6    mrg all), &lsquo;<samp>all</samp>&rsquo; (all but &lsquo;<samp>valgrind</samp>&rsquo;), &lsquo;<samp>release</samp>&rsquo; (cheapest
   1261  1.6    mrg checks &lsquo;<samp>assert,runtime</samp>&rsquo;) or &lsquo;<samp>none</samp>&rsquo; (same as &lsquo;<samp>no</samp>&rsquo;).
   1262  1.6    mrg Individual checks can be enabled with these flags &lsquo;<samp>assert</samp>&rsquo;,
   1263  1.6    mrg &lsquo;<samp>df</samp>&rsquo;, &lsquo;<samp>fold</samp>&rsquo;, &lsquo;<samp>gc</samp>&rsquo;, &lsquo;<samp>gcac</samp>&rsquo; &lsquo;<samp>misc</samp>&rsquo;, &lsquo;<samp>rtl</samp>&rsquo;,
   1264  1.6    mrg &lsquo;<samp>rtlflag</samp>&rsquo;, &lsquo;<samp>runtime</samp>&rsquo;, &lsquo;<samp>tree</samp>&rsquo;, and &lsquo;<samp>valgrind</samp>&rsquo;.
   1265  1.6    mrg </p>
   1266  1.6    mrg <p>The &lsquo;<samp>valgrind</samp>&rsquo; check requires the external <code>valgrind</code>
   1267  1.1    mrg simulator, available from <a href="http://valgrind.org/">http://valgrind.org/</a>.  The
   1268  1.6    mrg &lsquo;<samp>df</samp>&rsquo;, &lsquo;<samp>rtl</samp>&rsquo;, &lsquo;<samp>gcac</samp>&rsquo; and &lsquo;<samp>valgrind</samp>&rsquo; checks are very expensive.
   1269  1.6    mrg To disable all checking, &lsquo;<samp>--disable-checking</samp>&rsquo; or
   1270  1.6    mrg &lsquo;<samp>--enable-checking=none</samp>&rsquo; must be explicitly requested.  Disabling
   1271  1.1    mrg assertions will make the compiler and runtime slightly faster but
   1272  1.1    mrg increase the risk of undetected internal errors causing wrong code to be
   1273  1.1    mrg generated.
   1274  1.6    mrg </p>
   1275  1.6    mrg </dd>
   1276  1.6    mrg <dt><code>--disable-stage1-checking</code></dt>
   1277  1.6    mrg <dt><code>--enable-stage1-checking</code></dt>
   1278  1.6    mrg <dt><code>--enable-stage1-checking=<var>list</var></code></dt>
   1279  1.6    mrg <dd><p>If no <samp>--enable-checking</samp> option is specified the stage1
   1280  1.6    mrg compiler will be built with &lsquo;<samp>yes</samp>&rsquo; checking enabled, otherwise
   1281  1.1    mrg the stage1 checking flags are the same as specified by
   1282  1.6    mrg <samp>--enable-checking</samp>.  To build the stage1 compiler with
   1283  1.6    mrg different checking options use <samp>--enable-stage1-checking</samp>.
   1284  1.6    mrg The list of checking options is the same as for <samp>--enable-checking</samp>.
   1285  1.1    mrg If your system is too slow or too small to bootstrap a released compiler
   1286  1.6    mrg with checking for stage1 enabled, you can use &lsquo;<samp>--disable-stage1-checking</samp>&rsquo;
   1287  1.1    mrg to disable checking for the stage1 compiler.
   1288  1.6    mrg </p>
   1289  1.6    mrg </dd>
   1290  1.6    mrg <dt><code>--enable-coverage</code></dt>
   1291  1.6    mrg <dt><code>--enable-coverage=<var>level</var></code></dt>
   1292  1.6    mrg <dd><p>With this option, the compiler is built to collect self coverage
   1293  1.1    mrg information, every time it is run.  This is for internal development
   1294  1.1    mrg purposes, and only works when the compiler is being built with gcc.  The
   1295  1.1    mrg <var>level</var> argument controls whether the compiler is built optimized or
   1296  1.6    mrg not, values are &lsquo;<samp>opt</samp>&rsquo; and &lsquo;<samp>noopt</samp>&rsquo;.  For coverage analysis you
   1297  1.1    mrg want to disable optimization, for performance analysis you want to
   1298  1.1    mrg enable optimization.  When coverage is enabled, the default level is
   1299  1.1    mrg without optimization.
   1300  1.6    mrg </p>
   1301  1.6    mrg </dd>
   1302  1.6    mrg <dt><code>--enable-gather-detailed-mem-stats</code></dt>
   1303  1.6    mrg <dd><p>When this option is specified more detailed information on memory
   1304  1.1    mrg allocation is gathered.  This information is printed when using
   1305  1.6    mrg <samp>-fmem-report</samp>.
   1306  1.6    mrg </p>
   1307  1.6    mrg </dd>
   1308  1.6    mrg <dt><code>--enable-nls</code></dt>
   1309  1.6    mrg <dt><code>--disable-nls</code></dt>
   1310  1.6    mrg <dd><p>The <samp>--enable-nls</samp> option enables Native Language Support (NLS),
   1311  1.1    mrg which lets GCC output diagnostics in languages other than American
   1312  1.1    mrg English.  Native Language Support is enabled by default if not doing a
   1313  1.6    mrg canadian cross build.  The <samp>--disable-nls</samp> option disables NLS.
   1314  1.6    mrg </p>
   1315  1.6    mrg </dd>
   1316  1.6    mrg <dt><code>--with-included-gettext</code></dt>
   1317  1.6    mrg <dd><p>If NLS is enabled, the <samp>--with-included-gettext</samp> option causes the build
   1318  1.6    mrg procedure to prefer its copy of GNU <code>gettext</code>.
   1319  1.6    mrg </p>
   1320  1.6    mrg </dd>
   1321  1.6    mrg <dt><code>--with-catgets</code></dt>
   1322  1.6    mrg <dd><p>If NLS is enabled, and if the host lacks <code>gettext</code> but has the
   1323  1.1    mrg inferior <code>catgets</code> interface, the GCC build procedure normally
   1324  1.6    mrg ignores <code>catgets</code> and instead uses GCC&rsquo;s copy of the GNU
   1325  1.6    mrg <code>gettext</code> library.  The <samp>--with-catgets</samp> option causes the
   1326  1.6    mrg build procedure to use the host&rsquo;s <code>catgets</code> in this situation.
   1327  1.6    mrg </p>
   1328  1.6    mrg </dd>
   1329  1.6    mrg <dt><code>--with-libiconv-prefix=<var>dir</var></code></dt>
   1330  1.6    mrg <dd><p>Search for libiconv header files in <samp><var>dir</var>/include</samp> and
   1331  1.6    mrg libiconv library files in <samp><var>dir</var>/lib</samp>.
   1332  1.6    mrg </p>
   1333  1.6    mrg </dd>
   1334  1.6    mrg <dt><code>--enable-obsolete</code></dt>
   1335  1.6    mrg <dd><p>Enable configuration for an obsoleted system.  If you attempt to
   1336  1.1    mrg configure GCC for a system (build, host, or target) which has been
   1337  1.1    mrg obsoleted, and you do not specify this flag, configure will halt with an
   1338  1.1    mrg error message.
   1339  1.6    mrg </p>
   1340  1.6    mrg <p>All support for systems which have been obsoleted in one release of GCC
   1341  1.1    mrg is removed entirely in the next major release, unless someone steps
   1342  1.1    mrg forward to maintain the port.
   1343  1.6    mrg </p>
   1344  1.6    mrg </dd>
   1345  1.6    mrg <dt><code>--enable-decimal-float</code></dt>
   1346  1.6    mrg <dt><code>--enable-decimal-float=yes</code></dt>
   1347  1.6    mrg <dt><code>--enable-decimal-float=no</code></dt>
   1348  1.6    mrg <dt><code>--enable-decimal-float=bid</code></dt>
   1349  1.6    mrg <dt><code>--enable-decimal-float=dpd</code></dt>
   1350  1.6    mrg <dt><code>--disable-decimal-float</code></dt>
   1351  1.6    mrg <dd><p>Enable (or disable) support for the C decimal floating point extension
   1352  1.1    mrg that is in the IEEE 754-2008 standard.  This is enabled by default only
   1353  1.1    mrg on PowerPC, i386, and x86_64 GNU/Linux systems.  Other systems may also
   1354  1.1    mrg support it, but require the user to specifically enable it.  You can
   1355  1.1    mrg optionally control which decimal floating point format is used (either
   1356  1.6    mrg &lsquo;<samp>bid</samp>&rsquo; or &lsquo;<samp>dpd</samp>&rsquo;).  The &lsquo;<samp>bid</samp>&rsquo; (binary integer decimal)
   1357  1.6    mrg format is default on i386 and x86_64 systems, and the &lsquo;<samp>dpd</samp>&rsquo;
   1358  1.1    mrg (densely packed decimal) format is default on PowerPC systems.
   1359  1.6    mrg </p>
   1360  1.6    mrg </dd>
   1361  1.6    mrg <dt><code>--enable-fixed-point</code></dt>
   1362  1.6    mrg <dt><code>--disable-fixed-point</code></dt>
   1363  1.6    mrg <dd><p>Enable (or disable) support for C fixed-point arithmetic.
   1364  1.1    mrg This option is enabled by default for some targets (such as MIPS) which
   1365  1.1    mrg have hardware-support for fixed-point operations.  On other targets, you
   1366  1.1    mrg may enable this option manually.
   1367  1.6    mrg </p>
   1368  1.6    mrg </dd>
   1369  1.6    mrg <dt><code>--with-long-double-128</code></dt>
   1370  1.6    mrg <dd><p>Specify if <code>long double</code> type should be 128-bit by default on selected
   1371  1.1    mrg GNU/Linux architectures.  If using <code>--without-long-double-128</code>,
   1372  1.6    mrg <code>long double</code> will be by default 64-bit, the same as <code>double</code> type.
   1373  1.1    mrg When neither of these configure options are used, the default will be
   1374  1.1    mrg 128-bit <code>long double</code> when built against GNU C Library 2.4 and later,
   1375  1.1    mrg 64-bit <code>long double</code> otherwise.
   1376  1.6    mrg </p>
   1377  1.6    mrg </dd>
   1378  1.6    mrg <dt><code>--with-gmp=<var>pathname</var></code></dt>
   1379  1.6    mrg <dt><code>--with-gmp-include=<var>pathname</var></code></dt>
   1380  1.6    mrg <dt><code>--with-gmp-lib=<var>pathname</var></code></dt>
   1381  1.6    mrg <dt><code>--with-mpfr=<var>pathname</var></code></dt>
   1382  1.6    mrg <dt><code>--with-mpfr-include=<var>pathname</var></code></dt>
   1383  1.6    mrg <dt><code>--with-mpfr-lib=<var>pathname</var></code></dt>
   1384  1.6    mrg <dt><code>--with-mpc=<var>pathname</var></code></dt>
   1385  1.6    mrg <dt><code>--with-mpc-include=<var>pathname</var></code></dt>
   1386  1.6    mrg <dt><code>--with-mpc-lib=<var>pathname</var></code></dt>
   1387  1.6    mrg <dd><p>If you want to build GCC but do not have the GMP library, the MPFR
   1388  1.1    mrg library and/or the MPC library installed in a standard location and
   1389  1.3  skrll do not have their sources present in the GCC source tree then you
   1390  1.3  skrll can explicitly specify the directory where they are installed
   1391  1.6    mrg (&lsquo;<samp>--with-gmp=<var>gmpinstalldir</var></samp>&rsquo;,
   1392  1.6    mrg &lsquo;<samp>--with-mpfr=<var>mpfrinstalldir</var></samp>&rsquo;,
   1393  1.6    mrg &lsquo;<samp>--with-mpc=<var>mpcinstalldir</var></samp>&rsquo;).  The
   1394  1.6    mrg <samp>--with-gmp=<var>gmpinstalldir</var></samp> option is shorthand for
   1395  1.6    mrg <samp>--with-gmp-lib=<var>gmpinstalldir</var>/lib</samp> and
   1396  1.6    mrg <samp>--with-gmp-include=<var>gmpinstalldir</var>/include</samp>.  Likewise the
   1397  1.6    mrg <samp>--with-mpfr=<var>mpfrinstalldir</var></samp> option is shorthand for
   1398  1.6    mrg <samp>--with-mpfr-lib=<var>mpfrinstalldir</var>/lib</samp> and
   1399  1.6    mrg <samp>--with-mpfr-include=<var>mpfrinstalldir</var>/include</samp>, also the
   1400  1.6    mrg <samp>--with-mpc=<var>mpcinstalldir</var></samp> option is shorthand for
   1401  1.6    mrg <samp>--with-mpc-lib=<var>mpcinstalldir</var>/lib</samp> and
   1402  1.6    mrg <samp>--with-mpc-include=<var>mpcinstalldir</var>/include</samp>.  If these
   1403  1.1    mrg shorthand assumptions are not correct, you can use the explicit
   1404  1.3  skrll include and lib options directly.  You might also need to ensure the
   1405  1.3  skrll shared libraries can be found by the dynamic linker when building and
   1406  1.3  skrll using GCC, for example by setting the runtime shared library path
   1407  1.6    mrg variable (<code>LD_LIBRARY_PATH</code> on GNU/Linux and Solaris systems).
   1408  1.6    mrg </p>
   1409  1.6    mrg <p>These flags are applicable to the host platform only.  When building
   1410  1.3  skrll a cross compiler, they will not be used to configure target libraries.
   1411  1.6    mrg </p>
   1412  1.6    mrg </dd>
   1413  1.6    mrg <dt><code>--with-isl=<var>pathname</var></code></dt>
   1414  1.6    mrg <dt><code>--with-isl-include=<var>pathname</var></code></dt>
   1415  1.6    mrg <dt><code>--with-isl-lib=<var>pathname</var></code></dt>
   1416  1.6    mrg <dd><p>If you do not have the ISL library installed in a standard location and you
   1417  1.5    mrg want to build GCC, you can explicitly specify the directory where it is
   1418  1.6    mrg installed (&lsquo;<samp>--with-isl=<var>islinstalldir</var></samp>&rsquo;). The
   1419  1.6    mrg <samp>--with-isl=<var>islinstalldir</var></samp> option is shorthand for
   1420  1.6    mrg <samp>--with-isl-lib=<var>islinstalldir</var>/lib</samp> and
   1421  1.6    mrg <samp>--with-isl-include=<var>islinstalldir</var>/include</samp>. If this
   1422  1.5    mrg shorthand assumption is not correct, you can use the explicit
   1423  1.1    mrg include and lib options directly.
   1424  1.6    mrg </p>
   1425  1.6    mrg <p>These flags are applicable to the host platform only.  When building
   1426  1.3  skrll a cross compiler, they will not be used to configure target libraries.
   1427  1.6    mrg </p>
   1428  1.6    mrg </dd>
   1429  1.6    mrg <dt><code>--with-host-libstdcxx=<var>linker-args</var></code></dt>
   1430  1.6    mrg <dd><p>If you are linking with a static copy of PPL, you can use this option
   1431  1.1    mrg to specify how the linker should find the standard C++ library used
   1432  1.1    mrg internally by PPL.  Typical values of <var>linker-args</var> might be
   1433  1.6    mrg &lsquo;<samp>-lstdc++</samp>&rsquo; or &lsquo;<samp>-Wl,-Bstatic,-lstdc++,-Bdynamic -lm</samp>&rsquo;.  If you are
   1434  1.1    mrg linking with a shared copy of PPL, you probably do not need this
   1435  1.1    mrg option; shared library dependencies will cause the linker to search
   1436  1.1    mrg for the standard C++ library automatically.
   1437  1.6    mrg </p>
   1438  1.6    mrg </dd>
   1439  1.6    mrg <dt><code>--with-stage1-ldflags=<var>flags</var></code></dt>
   1440  1.6    mrg <dd><p>This option may be used to set linker flags to be used when linking
   1441  1.1    mrg stage 1 of GCC.  These are also used when linking GCC if configured with
   1442  1.6    mrg <samp>--disable-bootstrap</samp>.  By default no special flags are used.
   1443  1.6    mrg </p>
   1444  1.6    mrg </dd>
   1445  1.6    mrg <dt><code>--with-stage1-libs=<var>libs</var></code></dt>
   1446  1.6    mrg <dd><p>This option may be used to set libraries to be used when linking stage 1
   1447  1.1    mrg of GCC.  These are also used when linking GCC if configured with
   1448  1.6    mrg <samp>--disable-bootstrap</samp>.  The default is the argument to
   1449  1.6    mrg <samp>--with-host-libstdcxx</samp>, if specified.
   1450  1.6    mrg </p>
   1451  1.6    mrg </dd>
   1452  1.6    mrg <dt><code>--with-boot-ldflags=<var>flags</var></code></dt>
   1453  1.6    mrg <dd><p>This option may be used to set linker flags to be used when linking
   1454  1.3  skrll stage 2 and later when bootstrapping GCC.  If neither &ndash;with-boot-libs
   1455  1.3  skrll nor &ndash;with-host-libstdcxx is set to a value, then the default is
   1456  1.6    mrg &lsquo;<samp>-static-libstdc++ -static-libgcc</samp>&rsquo;.
   1457  1.6    mrg </p>
   1458  1.6    mrg </dd>
   1459  1.6    mrg <dt><code>--with-boot-libs=<var>libs</var></code></dt>
   1460  1.6    mrg <dd><p>This option may be used to set libraries to be used when linking stage 2
   1461  1.1    mrg and later when bootstrapping GCC.  The default is the argument to
   1462  1.6    mrg <samp>--with-host-libstdcxx</samp>, if specified.
   1463  1.6    mrg </p>
   1464  1.6    mrg </dd>
   1465  1.6    mrg <dt><code>--with-debug-prefix-map=<var>map</var></code></dt>
   1466  1.6    mrg <dd><p>Convert source directory names using <samp>-fdebug-prefix-map</samp> when
   1467  1.1    mrg building runtime libraries.  &lsquo;<samp><var>map</var></samp>&rsquo; is a space-separated
   1468  1.6    mrg list of maps of the form &lsquo;<samp><var>old</var>=<var>new</var></samp>&rsquo;.
   1469  1.6    mrg </p>
   1470  1.6    mrg </dd>
   1471  1.6    mrg <dt><code>--enable-linker-build-id</code></dt>
   1472  1.6    mrg <dd><p>Tells GCC to pass <samp>--build-id</samp> option to the linker for all final
   1473  1.6    mrg links (links performed without the <samp>-r</samp> or <samp>--relocatable</samp>
   1474  1.1    mrg option), if the linker supports it.  If you specify
   1475  1.6    mrg <samp>--enable-linker-build-id</samp>, but your linker does not
   1476  1.6    mrg support <samp>--build-id</samp> option, a warning is issued and the
   1477  1.6    mrg <samp>--enable-linker-build-id</samp> option is ignored.  The default is off.
   1478  1.6    mrg </p>
   1479  1.6    mrg </dd>
   1480  1.6    mrg <dt><code>--with-linker-hash-style=<var>choice</var></code></dt>
   1481  1.6    mrg <dd><p>Tells GCC to pass <samp>--hash-style=<var>choice</var></samp> option to the
   1482  1.3  skrll linker for all final links. <var>choice</var> can be one of
   1483  1.6    mrg &lsquo;<samp>sysv</samp>&rsquo;, &lsquo;<samp>gnu</samp>&rsquo;, and &lsquo;<samp>both</samp>&rsquo; where &lsquo;<samp>sysv</samp>&rsquo; is the default.
   1484  1.6    mrg </p>
   1485  1.6    mrg </dd>
   1486  1.6    mrg <dt><code>--enable-gnu-unique-object</code></dt>
   1487  1.6    mrg <dt><code>--disable-gnu-unique-object</code></dt>
   1488  1.6    mrg <dd><p>Tells GCC to use the gnu_unique_object relocation for C++ template
   1489  1.1    mrg static data members and inline function local statics.  Enabled by
   1490  1.5    mrg default for a toolchain with an assembler that accepts it and
   1491  1.1    mrg GLIBC 2.11 or above, otherwise disabled.
   1492  1.6    mrg </p>
   1493  1.6    mrg </dd>
   1494  1.6    mrg <dt><code>--with-diagnostics-color=<var>choice</var></code></dt>
   1495  1.6    mrg <dd><p>Tells GCC to use <var>choice</var> as the default for <samp>-fdiagnostics-color=</samp>
   1496  1.5    mrg option (if not used explicitly on the command line).  <var>choice</var>
   1497  1.6    mrg can be one of &lsquo;<samp>never</samp>&rsquo;, &lsquo;<samp>auto</samp>&rsquo;, &lsquo;<samp>always</samp>&rsquo;, and &lsquo;<samp>auto-if-env</samp>&rsquo;
   1498  1.6    mrg where &lsquo;<samp>auto</samp>&rsquo; is the default.  &lsquo;<samp>auto-if-env</samp>&rsquo; means that
   1499  1.6    mrg <samp>-fdiagnostics-color=auto</samp> will be the default if <code>GCC_COLORS</code>
   1500  1.5    mrg is present and non-empty in the environment, and
   1501  1.6    mrg <samp>-fdiagnostics-color=never</samp> otherwise.
   1502  1.6    mrg </p>
   1503  1.6    mrg </dd>
   1504  1.6    mrg <dt><code>--enable-lto</code></dt>
   1505  1.6    mrg <dt><code>--disable-lto</code></dt>
   1506  1.6    mrg <dd><p>Enable support for link-time optimization (LTO).  This is enabled by
   1507  1.6    mrg default, and may be disabled using <samp>--disable-lto</samp>.
   1508  1.6    mrg </p>
   1509  1.6    mrg </dd>
   1510  1.6    mrg <dt><code>--enable-linker-plugin-configure-flags=FLAGS</code></dt>
   1511  1.6    mrg <dt><code>--enable-linker-plugin-flags=FLAGS</code></dt>
   1512  1.6    mrg <dd><p>By default, linker plugins (such as the LTO plugin) are built for the
   1513  1.5    mrg host system architecture.  For the case that the linker has a
   1514  1.5    mrg different (but run-time compatible) architecture, these flags can be
   1515  1.5    mrg specified to build plugins that are compatible to the linker.  For
   1516  1.5    mrg example, if you are building GCC for a 64-bit x86_64
   1517  1.6    mrg (&lsquo;<samp>x86_64-unknown-linux-gnu</samp>&rsquo;) host system, but have a 32-bit x86
   1518  1.6    mrg GNU/Linux (&lsquo;<samp>i686-pc-linux-gnu</samp>&rsquo;) linker executable (which is
   1519  1.5    mrg executable on the former system), you can configure GCC as follows for
   1520  1.5    mrg getting compatible linker plugins:
   1521  1.6    mrg </p>
   1522  1.6    mrg <div class="smallexample">
   1523  1.6    mrg <pre class="smallexample">% <var>srcdir</var>/configure \
   1524  1.6    mrg     --host=x86_64-unknown-linux-gnu \
   1525  1.6    mrg     --enable-linker-plugin-configure-flags=--host=i686-pc-linux-gnu \
   1526  1.6    mrg     --enable-linker-plugin-flags='CC=gcc\ -m32\ -Wl,-rpath,[...]/i686-pc-linux-gnu/lib'
   1527  1.6    mrg </pre></div>
   1528  1.6    mrg 
   1529  1.6    mrg </dd>
   1530  1.6    mrg <dt><code>--with-plugin-ld=<var>pathname</var></code></dt>
   1531  1.6    mrg <dd><p>Enable an alternate linker to be used at link-time optimization (LTO)
   1532  1.6    mrg link time when <samp>-fuse-linker-plugin</samp> is enabled.
   1533  1.3  skrll This linker should have plugin support such as gold starting with
   1534  1.6    mrg version 2.20 or GNU ld starting with version 2.21.
   1535  1.6    mrg See <samp>-fuse-linker-plugin</samp> for details.
   1536  1.6    mrg </p>
   1537  1.6    mrg </dd>
   1538  1.6    mrg <dt><code>--enable-canonical-system-headers</code></dt>
   1539  1.6    mrg <dt><code>--disable-canonical-system-headers</code></dt>
   1540  1.6    mrg <dd><p>Enable system header path canonicalization for <samp>libcpp</samp>.  This can
   1541  1.3  skrll produce shorter header file paths in diagnostics and dependency output
   1542  1.3  skrll files, but these changed header paths may conflict with some compilation
   1543  1.3  skrll environments.  Enabled by default, and may be disabled using
   1544  1.6    mrg <samp>--disable-canonical-system-headers</samp>.
   1545  1.6    mrg </p>
   1546  1.6    mrg </dd>
   1547  1.6    mrg <dt><code>--with-glibc-version=<var>major</var>.<var>minor</var></code></dt>
   1548  1.6    mrg <dd><p>Tell GCC that when the GNU C Library (glibc) is used on the target it
   1549  1.5    mrg will be version <var>major</var>.<var>minor</var> or later.  Normally this can
   1550  1.6    mrg be detected from the C library&rsquo;s header files, but this option may be
   1551  1.5    mrg needed when bootstrapping a cross toolchain without the header files
   1552  1.5    mrg available for building the initial bootstrap compiler.
   1553  1.6    mrg </p>
   1554  1.6    mrg <p>If GCC is configured with some multilibs that use glibc and some that
   1555  1.6    mrg do not, this option applies only to the multilibs that use glibc.
   1556  1.5    mrg However, such configurations may not work well as not all the relevant
   1557  1.5    mrg configuration in GCC is on a per-multilib basis.
   1558  1.6    mrg </p>
   1559  1.6    mrg </dd>
   1560  1.6    mrg <dt><code>--enable-as-accelerator-for=<var>target</var></code></dt>
   1561  1.6    mrg <dd><p>Build as offload target compiler. Specify offload host triple by <var>target</var>.
   1562  1.6    mrg </p>
   1563  1.6    mrg </dd>
   1564  1.6    mrg <dt><code>--enable-offload-targets=<var>target1</var>[=<var>path1</var>],&hellip;,<var>targetN</var>[=<var>pathN</var>]</code></dt>
   1565  1.6    mrg <dd><p>Enable offloading to targets <var>target1</var>, &hellip;, <var>targetN</var>.
   1566  1.5    mrg Offload compilers are expected to be already installed.  Default search
   1567  1.5    mrg path for them is <samp><var>exec-prefix</var></samp>, but it can be changed by
   1568  1.6    mrg specifying paths <var>path1</var>, &hellip;, <var>pathN</var>.
   1569  1.6    mrg </p>
   1570  1.6    mrg <div class="smallexample">
   1571  1.6    mrg <pre class="smallexample">% <var>srcdir</var>/configure \
   1572  1.6    mrg     --enable-offload-target=i686-unknown-linux-gnu=/path/to/i686/compiler,x86_64-pc-linux-gnu
   1573  1.6    mrg </pre></div>
   1574  1.6    mrg </dd>
   1575  1.6    mrg </dl>
   1576  1.1    mrg 
   1577  1.6    mrg <a name="Cross_002dCompiler_002dSpecific-Options"></a>
   1578  1.6    mrg <h4 class="subheading">Cross-Compiler-Specific Options</h4>
   1579  1.1    mrg <p>The following options only apply to building cross compilers.
   1580  1.6    mrg </p>
   1581  1.6    mrg <dl compact="compact">
   1582  1.6    mrg <dt><code>--with-sysroot</code></dt>
   1583  1.6    mrg <dt><code>--with-sysroot=<var>dir</var></code></dt>
   1584  1.6    mrg <dd><p>Tells GCC to consider <var>dir</var> as the root of a tree that contains
   1585  1.6    mrg (a subset of) the root filesystem of the target operating system.
   1586  1.1    mrg Target system headers, libraries and run-time object files will be
   1587  1.3  skrll searched for in there.  More specifically, this acts as if
   1588  1.6    mrg <samp>--sysroot=<var>dir</var></samp> was added to the default options of the built
   1589  1.1    mrg compiler.  The specified directory is not copied into the
   1590  1.6    mrg install tree, unlike the options <samp>--with-headers</samp> and
   1591  1.6    mrg <samp>--with-libs</samp> that this option obsoletes.  The default value,
   1592  1.6    mrg in case <samp>--with-sysroot</samp> is not given an argument, is
   1593  1.6    mrg <samp>${gcc_tooldir}/sys-root</samp>.  If the specified directory is a
   1594  1.6    mrg subdirectory of <samp>${exec_prefix}</samp>, then it will be found relative to
   1595  1.1    mrg the GCC binaries if the installation tree is moved.
   1596  1.6    mrg </p>
   1597  1.6    mrg <p>This option affects the system root for the compiler used to build
   1598  1.1    mrg target libraries (which runs on the build system) and the compiler newly
   1599  1.1    mrg installed with <code>make install</code>; it does not affect the compiler which is
   1600  1.1    mrg used to build GCC itself.
   1601  1.6    mrg </p>
   1602  1.6    mrg <p>If you specify the <samp>--with-native-system-header-dir=<var>dirname</var></samp>
   1603  1.3  skrll option then the compiler will search that directory within <var>dirname</var> for
   1604  1.6    mrg native system headers rather than the default <samp>/usr/include</samp>.
   1605  1.6    mrg </p>
   1606  1.6    mrg </dd>
   1607  1.6    mrg <dt><code>--with-build-sysroot</code></dt>
   1608  1.6    mrg <dt><code>--with-build-sysroot=<var>dir</var></code></dt>
   1609  1.6    mrg <dd><p>Tells GCC to consider <var>dir</var> as the system root (see
   1610  1.6    mrg <samp>--with-sysroot</samp>) while building target libraries, instead of
   1611  1.6    mrg the directory specified with <samp>--with-sysroot</samp>.  This option is
   1612  1.6    mrg only useful when you are already using <samp>--with-sysroot</samp>.  You
   1613  1.6    mrg can use <samp>--with-build-sysroot</samp> when you are configuring with
   1614  1.6    mrg <samp>--prefix</samp> set to a directory that is different from the one in
   1615  1.1    mrg which you are installing GCC and your target libraries.
   1616  1.6    mrg </p>
   1617  1.6    mrg <p>This option affects the system root for the compiler used to build
   1618  1.1    mrg target libraries (which runs on the build system); it does not affect
   1619  1.1    mrg the compiler which is used to build GCC itself.
   1620  1.6    mrg </p>
   1621  1.6    mrg <p>If you specify the <samp>--with-native-system-header-dir=<var>dirname</var></samp>
   1622  1.3  skrll option then the compiler will search that directory within <var>dirname</var> for
   1623  1.6    mrg native system headers rather than the default <samp>/usr/include</samp>.
   1624  1.6    mrg </p>
   1625  1.6    mrg </dd>
   1626  1.6    mrg <dt><code>--with-headers</code></dt>
   1627  1.6    mrg <dt><code>--with-headers=<var>dir</var></code></dt>
   1628  1.6    mrg <dd><p>Deprecated in favor of <samp>--with-sysroot</samp>.
   1629  1.6    mrg Specifies that target headers are available when building a cross compiler.
   1630  1.1    mrg The <var>dir</var> argument specifies a directory which has the target include
   1631  1.6    mrg files.  These include files will be copied into the <samp>gcc</samp> install
   1632  1.6    mrg directory.  <em>This option with the <var>dir</var> argument is required</em> when
   1633  1.6    mrg building a cross compiler, if <samp><var>prefix</var>/<var>target</var>/sys-include</samp>
   1634  1.6    mrg doesn&rsquo;t pre-exist.  If <samp><var>prefix</var>/<var>target</var>/sys-include</samp> does
   1635  1.6    mrg pre-exist, the <var>dir</var> argument may be omitted.  <code>fixincludes</code>
   1636  1.1    mrg will be run on these files to make them compatible with GCC.
   1637  1.6    mrg </p>
   1638  1.6    mrg </dd>
   1639  1.6    mrg <dt><code>--without-headers</code></dt>
   1640  1.6    mrg <dd><p>Tells GCC not use any target headers from a libc when building a cross
   1641  1.1    mrg compiler.  When crossing to GNU/Linux, you need the headers so GCC
   1642  1.1    mrg can build the exception handling for libgcc.
   1643  1.6    mrg </p>
   1644  1.6    mrg </dd>
   1645  1.6    mrg <dt><code>--with-libs</code></dt>
   1646  1.6    mrg <dt><code>--with-libs=&quot;<var>dir1</var> <var>dir2</var> &hellip; <var>dirN</var>&quot;</code></dt>
   1647  1.6    mrg <dd><p>Deprecated in favor of <samp>--with-sysroot</samp>.
   1648  1.1    mrg Specifies a list of directories which contain the target runtime
   1649  1.6    mrg libraries.  These libraries will be copied into the <samp>gcc</samp> install
   1650  1.1    mrg directory.  If the directory list is omitted, this option has no
   1651  1.1    mrg effect.
   1652  1.6    mrg </p>
   1653  1.6    mrg </dd>
   1654  1.6    mrg <dt><code>--with-newlib</code></dt>
   1655  1.6    mrg <dd><p>Specifies that &lsquo;<samp>newlib</samp>&rsquo; is
   1656  1.1    mrg being used as the target C library.  This causes <code>__eprintf</code> to be
   1657  1.6    mrg omitted from <samp>libgcc.a</samp> on the assumption that it will be provided by
   1658  1.6    mrg &lsquo;<samp>newlib</samp>&rsquo;.
   1659  1.6    mrg </p>
   1660  1.6    mrg </dd>
   1661  1.6    mrg <dt><code>--with-avrlibc</code></dt>
   1662  1.6    mrg <dd><p>Specifies that &lsquo;<samp>AVR-Libc</samp>&rsquo; is
   1663  1.3  skrll being used as the target C library.  This causes float support
   1664  1.6    mrg functions like <code>__addsf3</code> to be omitted from <samp>libgcc.a</samp> on
   1665  1.6    mrg the assumption that it will be provided by <samp>libm.a</samp>.  For more
   1666  1.6    mrg technical details, cf. <a href="http://gcc.gnu.org/PR54461">PR54461</a>.
   1667  1.3  skrll This option is only supported for the AVR target.  It is not supported for
   1668  1.3  skrll RTEMS configurations, which currently use newlib.  The option is
   1669  1.3  skrll supported since version 4.7.2 and is the default in 4.8.0 and newer.
   1670  1.6    mrg </p>
   1671  1.6    mrg </dd>
   1672  1.6    mrg <dt><code>--with-nds32-lib=<var>library</var></code></dt>
   1673  1.6    mrg <dd><p>Specifies that <var>library</var> setting is used for building <samp>libgcc.a</samp>.
   1674  1.6    mrg Currently, the valid <var>library</var> is &lsquo;<samp>newlib</samp>&rsquo; or &lsquo;<samp>mculib</samp>&rsquo;.
   1675  1.5    mrg This option is only supported for the NDS32 target.
   1676  1.6    mrg </p>
   1677  1.6    mrg </dd>
   1678  1.6    mrg <dt><code>--with-build-time-tools=<var>dir</var></code></dt>
   1679  1.6    mrg <dd><p>Specifies where to find the set of target tools (assembler, linker, etc.)
   1680  1.1    mrg that will be used while building GCC itself.  This option can be useful
   1681  1.1    mrg if the directory layouts are different between the system you are building
   1682  1.1    mrg GCC on, and the system where you will deploy it.
   1683  1.6    mrg </p>
   1684  1.6    mrg <p>For example, on an &lsquo;<samp>ia64-hp-hpux</samp>&rsquo; system, you may have the GNU
   1685  1.6    mrg assembler and linker in <samp>/usr/bin</samp>, and the native tools in a
   1686  1.6    mrg different path, and build a toolchain that expects to find the
   1687  1.6    mrg native tools in <samp>/usr/bin</samp>.
   1688  1.6    mrg </p>
   1689  1.6    mrg <p>When you use this option, you should ensure that <var>dir</var> includes
   1690  1.6    mrg <code>ar</code>, <code>as</code>, <code>ld</code>, <code>nm</code>,
   1691  1.6    mrg <code>ranlib</code> and <code>strip</code> if necessary, and possibly
   1692  1.6    mrg <code>objdump</code>.  Otherwise, GCC may use an inconsistent set of
   1693  1.6    mrg tools.
   1694  1.6    mrg </p></dd>
   1695  1.6    mrg </dl>
   1696  1.1    mrg 
   1697  1.6    mrg <a name="Overriding-configure-test-results"></a>
   1698  1.6    mrg <h4 class="subsubheading">Overriding <code>configure</code> test results</h4>
   1699  1.1    mrg 
   1700  1.6    mrg <p>Sometimes, it might be necessary to override the result of some
   1701  1.6    mrg <code>configure</code> test, for example in order to ease porting to a new
   1702  1.6    mrg system or work around a bug in a test.  The toplevel <code>configure</code>
   1703  1.6    mrg script provides three variables for this:
   1704  1.6    mrg </p>
   1705  1.6    mrg <dl compact="compact">
   1706  1.6    mrg <dt><code>build_configargs</code></dt>
   1707  1.6    mrg <dd><a name="index-build_005fconfigargs"></a>
   1708  1.6    mrg <p>The contents of this variable is passed to all build <code>configure</code>
   1709  1.6    mrg scripts.
   1710  1.6    mrg </p>
   1711  1.6    mrg </dd>
   1712  1.6    mrg <dt><code>host_configargs</code></dt>
   1713  1.6    mrg <dd><a name="index-host_005fconfigargs"></a>
   1714  1.6    mrg <p>The contents of this variable is passed to all host <code>configure</code>
   1715  1.6    mrg scripts.
   1716  1.6    mrg </p>
   1717  1.6    mrg </dd>
   1718  1.6    mrg <dt><code>target_configargs</code></dt>
   1719  1.6    mrg <dd><a name="index-target_005fconfigargs"></a>
   1720  1.6    mrg <p>The contents of this variable is passed to all target <code>configure</code>
   1721  1.6    mrg scripts.
   1722  1.6    mrg </p>
   1723  1.6    mrg </dd>
   1724  1.1    mrg </dl>
   1725  1.1    mrg 
   1726  1.6    mrg <p>In order to avoid shell and <code>make</code> quoting issues for complex
   1727  1.6    mrg overrides, you can pass a setting for <code>CONFIG_SITE</code> and set
   1728  1.6    mrg variables in the site file.
   1729  1.6    mrg </p>
   1730  1.6    mrg <a name="Java_002dSpecific-Options"></a>
   1731  1.6    mrg <h4 class="subheading">Java-Specific Options</h4>
   1732  1.1    mrg 
   1733  1.1    mrg <p>The following option applies to the build of the Java front end.
   1734  1.6    mrg </p>
   1735  1.6    mrg <dl compact="compact">
   1736  1.6    mrg <dt><code>--disable-libgcj</code></dt>
   1737  1.6    mrg <dd><p>Specify that the run-time libraries
   1738  1.1    mrg used by GCJ should not be built.  This is useful in case you intend
   1739  1.6    mrg to use GCJ with some other run-time, or you&rsquo;re going to install it
   1740  1.1    mrg separately, or it just happens not to build on your particular
   1741  1.1    mrg machine.  In general, if the Java front end is enabled, the GCJ
   1742  1.6    mrg libraries will be enabled too, unless they&rsquo;re known to not work on
   1743  1.6    mrg the target platform.  If GCJ is enabled but &lsquo;<samp>libgcj</samp>&rsquo; isn&rsquo;t built, you
   1744  1.1    mrg may need to port it; in this case, before modifying the top-level
   1745  1.6    mrg <samp>configure.in</samp> so that &lsquo;<samp>libgcj</samp>&rsquo; is enabled by default on this platform,
   1746  1.6    mrg you may use <samp>--enable-libgcj</samp> to override the default.
   1747  1.6    mrg </p>
   1748  1.6    mrg </dd>
   1749  1.6    mrg </dl>
   1750  1.1    mrg 
   1751  1.6    mrg <p>The following options apply to building &lsquo;<samp>libgcj</samp>&rsquo;.
   1752  1.6    mrg </p>
   1753  1.6    mrg <a name="General-Options"></a>
   1754  1.6    mrg <h4 class="subsubheading">General Options</h4>
   1755  1.6    mrg 
   1756  1.6    mrg <dl compact="compact">
   1757  1.6    mrg <dt><code>--enable-java-maintainer-mode</code></dt>
   1758  1.6    mrg <dd><p>By default the &lsquo;<samp>libjava</samp>&rsquo; build will not attempt to compile the
   1759  1.6    mrg <samp>.java</samp> source files to <samp>.class</samp>.  Instead, it will use the
   1760  1.6    mrg <samp>.class</samp> files from the source tree.  If you use this option you
   1761  1.6    mrg must have executables named <code>ecj1</code> and <code>gjavah</code> in your path
   1762  1.1    mrg for use by the build.  You must use this option if you intend to
   1763  1.6    mrg modify any <samp>.java</samp> files in <samp>libjava</samp>.
   1764  1.6    mrg </p>
   1765  1.6    mrg </dd>
   1766  1.6    mrg <dt><code>--with-java-home=<var>dirname</var></code></dt>
   1767  1.6    mrg <dd><p>This &lsquo;<samp>libjava</samp>&rsquo; option overrides the default value of the
   1768  1.6    mrg &lsquo;<samp>java.home</samp>&rsquo; system property.  It is also used to set
   1769  1.6    mrg &lsquo;<samp>sun.boot.class.path</samp>&rsquo; to <samp><var>dirname</var>/lib/rt.jar</samp>.  By
   1770  1.6    mrg default &lsquo;<samp>java.home</samp>&rsquo; is set to <samp><var>prefix</var></samp> and
   1771  1.6    mrg &lsquo;<samp>sun.boot.class.path</samp>&rsquo; to
   1772  1.6    mrg <samp><var>datadir</var>/java/libgcj-<var>version</var>.jar</samp>.
   1773  1.6    mrg </p>
   1774  1.6    mrg </dd>
   1775  1.6    mrg <dt><code>--with-ecj-jar=<var>filename</var></code></dt>
   1776  1.6    mrg <dd><p>This option can be used to specify the location of an external jar
   1777  1.1    mrg file containing the Eclipse Java compiler.  A specially modified
   1778  1.6    mrg version of this compiler is used by <code>gcj</code> to parse
   1779  1.6    mrg <samp>.java</samp> source files.  If this option is given, the
   1780  1.6    mrg &lsquo;<samp>libjava</samp>&rsquo; build will create and install an <samp>ecj1</samp> executable
   1781  1.1    mrg which uses this jar file at runtime.
   1782  1.6    mrg </p>
   1783  1.6    mrg <p>If this option is not given, but an <samp>ecj.jar</samp> file is found in
   1784  1.6    mrg the topmost source tree at configure time, then the &lsquo;<samp>libgcj</samp>&rsquo;
   1785  1.6    mrg build will create and install <samp>ecj1</samp>, and will also install the
   1786  1.6    mrg discovered <samp>ecj.jar</samp> into a suitable place in the install tree.
   1787  1.6    mrg </p>
   1788  1.6    mrg <p>If <samp>ecj1</samp> is not installed, then the user will have to supply one
   1789  1.6    mrg on his path in order for <code>gcj</code> to properly parse <samp>.java</samp>
   1790  1.1    mrg source files.  A suitable jar is available from
   1791  1.1    mrg <a href="ftp://sourceware.org/pub/java/">ftp://sourceware.org/pub/java/</a>.
   1792  1.6    mrg </p>
   1793  1.6    mrg </dd>
   1794  1.6    mrg <dt><code>--disable-getenv-properties</code></dt>
   1795  1.6    mrg <dd><p>Don&rsquo;t set system properties from <code>GCJ_PROPERTIES</code>.
   1796  1.6    mrg </p>
   1797  1.6    mrg </dd>
   1798  1.6    mrg <dt><code>--enable-hash-synchronization</code></dt>
   1799  1.6    mrg <dd><p>Use a global hash table for monitor locks.  Ordinarily,
   1800  1.6    mrg &lsquo;<samp>libgcj</samp>&rsquo;&rsquo;s &lsquo;<samp>configure</samp>&rsquo; script automatically makes
   1801  1.1    mrg the correct choice for this option for your platform.  Only use
   1802  1.1    mrg this if you know you need the library to be configured differently.
   1803  1.6    mrg </p>
   1804  1.6    mrg </dd>
   1805  1.6    mrg <dt><code>--enable-interpreter</code></dt>
   1806  1.6    mrg <dd><p>Enable the Java interpreter.  The interpreter is automatically
   1807  1.1    mrg enabled by default on all platforms that support it.  This option
   1808  1.1    mrg is really only useful if you want to disable the interpreter
   1809  1.6    mrg (using <samp>--disable-interpreter</samp>).
   1810  1.6    mrg </p>
   1811  1.6    mrg </dd>
   1812  1.6    mrg <dt><code>--disable-java-net</code></dt>
   1813  1.6    mrg <dd><p>Disable java.net.  This disables the native part of java.net only,
   1814  1.1    mrg using non-functional stubs for native method implementations.
   1815  1.6    mrg </p>
   1816  1.6    mrg </dd>
   1817  1.6    mrg <dt><code>--disable-jvmpi</code></dt>
   1818  1.6    mrg <dd><p>Disable JVMPI support.
   1819  1.6    mrg </p>
   1820  1.6    mrg </dd>
   1821  1.6    mrg <dt><code>--disable-libgcj-bc</code></dt>
   1822  1.6    mrg <dd><p>Disable BC ABI compilation of certain parts of libgcj.  By default,
   1823  1.6    mrg some portions of libgcj are compiled with <samp>-findirect-dispatch</samp>
   1824  1.6    mrg and <samp>-fno-indirect-classes</samp>, allowing them to be overridden at
   1825  1.1    mrg run-time.
   1826  1.6    mrg </p>
   1827  1.6    mrg <p>If <samp>--disable-libgcj-bc</samp> is specified, libgcj is built without
   1828  1.1    mrg these options.  This allows the compile-time linker to resolve
   1829  1.1    mrg dependencies when statically linking to libgcj.  However it makes it
   1830  1.1    mrg impossible to override the affected portions of libgcj at run-time.
   1831  1.6    mrg </p>
   1832  1.6    mrg </dd>
   1833  1.6    mrg <dt><code>--enable-reduced-reflection</code></dt>
   1834  1.6    mrg <dd><p>Build most of libgcj with <samp>-freduced-reflection</samp>.  This reduces
   1835  1.1    mrg the size of libgcj at the expense of not being able to do accurate
   1836  1.1    mrg reflection on the classes it contains.  This option is safe if you
   1837  1.1    mrg know that code using libgcj will never use reflection on the standard
   1838  1.1    mrg runtime classes in libgcj (including using serialization, RMI or CORBA).
   1839  1.6    mrg </p>
   1840  1.6    mrg </dd>
   1841  1.6    mrg <dt><code>--with-ecos</code></dt>
   1842  1.6    mrg <dd><p>Enable runtime eCos target support.
   1843  1.6    mrg </p>
   1844  1.6    mrg </dd>
   1845  1.6    mrg <dt><code>--without-libffi</code></dt>
   1846  1.6    mrg <dd><p>Don&rsquo;t use &lsquo;<samp>libffi</samp>&rsquo;.  This will disable the interpreter and JNI
   1847  1.6    mrg support as well, as these require &lsquo;<samp>libffi</samp>&rsquo; to work.
   1848  1.6    mrg </p>
   1849  1.6    mrg </dd>
   1850  1.6    mrg <dt><code>--enable-libgcj-debug</code></dt>
   1851  1.6    mrg <dd><p>Enable runtime debugging code.
   1852  1.6    mrg </p>
   1853  1.6    mrg </dd>
   1854  1.6    mrg <dt><code>--enable-libgcj-multifile</code></dt>
   1855  1.6    mrg <dd><p>If specified, causes all <samp>.java</samp> source files to be
   1856  1.6    mrg compiled into <samp>.class</samp> files in one invocation of
   1857  1.6    mrg &lsquo;<samp>gcj</samp>&rsquo;.  This can speed up build time, but is more
   1858  1.1    mrg resource-intensive.  If this option is unspecified or
   1859  1.6    mrg disabled, &lsquo;<samp>gcj</samp>&rsquo; is invoked once for each <samp>.java</samp>
   1860  1.6    mrg file to compile into a <samp>.class</samp> file.
   1861  1.6    mrg </p>
   1862  1.6    mrg </dd>
   1863  1.6    mrg <dt><code>--with-libiconv-prefix=DIR</code></dt>
   1864  1.6    mrg <dd><p>Search for libiconv in <samp>DIR/include</samp> and <samp>DIR/lib</samp>.
   1865  1.6    mrg </p>
   1866  1.6    mrg </dd>
   1867  1.6    mrg <dt><code>--with-system-zlib</code></dt>
   1868  1.6    mrg <dd><p>Use installed &lsquo;<samp>zlib</samp>&rsquo; rather than that included with GCC.
   1869  1.6    mrg </p>
   1870  1.6    mrg </dd>
   1871  1.6    mrg <dt><code>--with-win32-nlsapi=ansi, unicows or unicode</code></dt>
   1872  1.6    mrg <dd><p>Indicates how MinGW &lsquo;<samp>libgcj</samp>&rsquo; translates between UNICODE
   1873  1.1    mrg characters and the Win32 API.
   1874  1.6    mrg </p>
   1875  1.6    mrg </dd>
   1876  1.6    mrg <dt><code>--enable-java-home</code></dt>
   1877  1.6    mrg <dd><p>If enabled, this creates a JPackage compatible SDK environment during install.
   1878  1.1    mrg Note that if &ndash;enable-java-home is used, &ndash;with-arch-directory=ARCH must also
   1879  1.1    mrg be specified.
   1880  1.6    mrg </p>
   1881  1.6    mrg </dd>
   1882  1.6    mrg <dt><code>--with-arch-directory=ARCH</code></dt>
   1883  1.6    mrg <dd><p>Specifies the name to use for the <samp>jre/lib/ARCH</samp> directory in the SDK
   1884  1.1    mrg environment created when &ndash;enable-java-home is passed. Typical names for this
   1885  1.1    mrg directory include i386, amd64, ia64, etc.
   1886  1.6    mrg </p>
   1887  1.6    mrg </dd>
   1888  1.6    mrg <dt><code>--with-os-directory=DIR</code></dt>
   1889  1.6    mrg <dd><p>Specifies the OS directory for the SDK include directory. This is set to auto
   1890  1.6    mrg detect, and is typically &rsquo;linux&rsquo;.
   1891  1.6    mrg </p>
   1892  1.6    mrg </dd>
   1893  1.6    mrg <dt><code>--with-origin-name=NAME</code></dt>
   1894  1.6    mrg <dd><p>Specifies the JPackage origin name. This defaults to the &rsquo;gcj&rsquo; in
   1895  1.1    mrg java-1.5.0-gcj.
   1896  1.6    mrg </p>
   1897  1.6    mrg </dd>
   1898  1.6    mrg <dt><code>--with-arch-suffix=SUFFIX</code></dt>
   1899  1.6    mrg <dd><p>Specifies the suffix for the sdk directory. Defaults to the empty string.
   1900  1.6    mrg Examples include &rsquo;.x86_64&rsquo; in &rsquo;java-1.5.0-gcj-1.5.0.0.x86_64&rsquo;.
   1901  1.6    mrg </p>
   1902  1.6    mrg </dd>
   1903  1.6    mrg <dt><code>--with-jvm-root-dir=DIR</code></dt>
   1904  1.6    mrg <dd><p>Specifies where to install the SDK. Default is $(prefix)/lib/jvm.
   1905  1.6    mrg </p>
   1906  1.6    mrg </dd>
   1907  1.6    mrg <dt><code>--with-jvm-jar-dir=DIR</code></dt>
   1908  1.6    mrg <dd><p>Specifies where to install jars. Default is $(prefix)/lib/jvm-exports.
   1909  1.6    mrg </p>
   1910  1.6    mrg </dd>
   1911  1.6    mrg <dt><code>--with-python-dir=DIR</code></dt>
   1912  1.6    mrg <dd><p>Specifies where to install the Python modules used for aot-compile. DIR should
   1913  1.1    mrg not include the prefix used in installation. For example, if the Python modules
   1914  1.1    mrg are to be installed in /usr/lib/python2.5/site-packages, then
   1915  1.1    mrg &ndash;with-python-dir=/lib/python2.5/site-packages should be passed. If this is
   1916  1.1    mrg not specified, then the Python modules are installed in $(prefix)/share/python.
   1917  1.6    mrg </p>
   1918  1.6    mrg </dd>
   1919  1.6    mrg <dt><code>--enable-aot-compile-rpm</code></dt>
   1920  1.6    mrg <dd><p>Adds aot-compile-rpm to the list of installed scripts.
   1921  1.6    mrg </p>
   1922  1.6    mrg </dd>
   1923  1.6    mrg <dt><code>--enable-browser-plugin</code></dt>
   1924  1.6    mrg <dd><p>Build the gcjwebplugin web browser plugin.
   1925  1.6    mrg </p>
   1926  1.6    mrg </dd>
   1927  1.6    mrg <dt><code>--enable-static-libjava</code></dt>
   1928  1.6    mrg <dd><p>Build static libraries in libjava. The default is to only build shared
   1929  1.3  skrll libraries.
   1930  1.6    mrg </p>
   1931  1.6    mrg <dl compact="compact">
   1932  1.6    mrg <dt><code>ansi</code></dt>
   1933  1.6    mrg <dd><p>Use the single-byte <code>char</code> and the Win32 A functions natively,
   1934  1.1    mrg translating to and from UNICODE when using these functions.  If
   1935  1.1    mrg unspecified, this is the default.
   1936  1.6    mrg </p>
   1937  1.6    mrg </dd>
   1938  1.6    mrg <dt><code>unicows</code></dt>
   1939  1.6    mrg <dd><p>Use the <code>WCHAR</code> and Win32 W functions natively.  Adds
   1940  1.6    mrg <code>-lunicows</code> to <samp>libgcj.spec</samp> to link with &lsquo;<samp>libunicows</samp>&rsquo;.
   1941  1.6    mrg <samp>unicows.dll</samp> needs to be deployed on Microsoft Windows 9X machines
   1942  1.6    mrg running built executables.  <samp>libunicows.a</samp>, an open-source
   1943  1.6    mrg import library around Microsoft&rsquo;s <code>unicows.dll</code>, is obtained from
   1944  1.1    mrg <a href="http://libunicows.sourceforge.net/">http://libunicows.sourceforge.net/</a>, which also gives details
   1945  1.6    mrg on getting <samp>unicows.dll</samp> from Microsoft.
   1946  1.6    mrg </p>
   1947  1.6    mrg </dd>
   1948  1.6    mrg <dt><code>unicode</code></dt>
   1949  1.6    mrg <dd><p>Use the <code>WCHAR</code> and Win32 W functions natively.  Does <em>not</em>
   1950  1.6    mrg add <code>-lunicows</code> to <samp>libgcj.spec</samp>.  The built executables will
   1951  1.6    mrg only run on Microsoft Windows NT and above.
   1952  1.6    mrg </p></dd>
   1953  1.6    mrg </dl>
   1954  1.6    mrg </dd>
   1955  1.1    mrg </dl>
   1956  1.1    mrg 
   1957  1.6    mrg <a name="AWT_002dSpecific-Options"></a>
   1958  1.6    mrg <h4 class="subsubheading">AWT-Specific Options</h4>
   1959  1.1    mrg 
   1960  1.6    mrg <dl compact="compact">
   1961  1.6    mrg <dt><code>--with-x</code></dt>
   1962  1.6    mrg <dd><p>Use the X Window System.
   1963  1.6    mrg </p>
   1964  1.6    mrg </dd>
   1965  1.6    mrg <dt><code>--enable-java-awt=PEER(S)</code></dt>
   1966  1.6    mrg <dd><p>Specifies the AWT peer library or libraries to build alongside
   1967  1.6    mrg &lsquo;<samp>libgcj</samp>&rsquo;.  If this option is unspecified or disabled, AWT
   1968  1.6    mrg will be non-functional.  Current valid values are <samp>gtk</samp> and
   1969  1.6    mrg <samp>xlib</samp>.  Multiple libraries should be separated by a
   1970  1.6    mrg comma (i.e. <samp>--enable-java-awt=gtk,xlib</samp>).
   1971  1.6    mrg </p>
   1972  1.6    mrg </dd>
   1973  1.6    mrg <dt><code>--enable-gtk-cairo</code></dt>
   1974  1.6    mrg <dd><p>Build the cairo Graphics2D implementation on GTK.
   1975  1.6    mrg </p>
   1976  1.6    mrg </dd>
   1977  1.6    mrg <dt><code>--enable-java-gc=TYPE</code></dt>
   1978  1.6    mrg <dd><p>Choose garbage collector.  Defaults to <samp>boehm</samp> if unspecified.
   1979  1.6    mrg </p>
   1980  1.6    mrg </dd>
   1981  1.6    mrg <dt><code>--disable-gtktest</code></dt>
   1982  1.6    mrg <dd><p>Do not try to compile and run a test GTK+ program.
   1983  1.6    mrg </p>
   1984  1.6    mrg </dd>
   1985  1.6    mrg <dt><code>--disable-glibtest</code></dt>
   1986  1.6    mrg <dd><p>Do not try to compile and run a test GLIB program.
   1987  1.6    mrg </p>
   1988  1.6    mrg </dd>
   1989  1.6    mrg <dt><code>--with-libart-prefix=PFX</code></dt>
   1990  1.6    mrg <dd><p>Prefix where libart is installed (optional).
   1991  1.6    mrg </p>
   1992  1.6    mrg </dd>
   1993  1.6    mrg <dt><code>--with-libart-exec-prefix=PFX</code></dt>
   1994  1.6    mrg <dd><p>Exec prefix where libart is installed (optional).
   1995  1.6    mrg </p>
   1996  1.6    mrg </dd>
   1997  1.6    mrg <dt><code>--disable-libarttest</code></dt>
   1998  1.6    mrg <dd><p>Do not try to compile and run a test libart program.
   1999  1.6    mrg </p>
   2000  1.6    mrg </dd>
   2001  1.6    mrg </dl>
   2002  1.1    mrg 
   2003  1.1    mrg 
   2004  1.6    mrg <hr />
   2005  1.6    mrg <p>
   2006  1.6    mrg <p><a href="./index.html">Return to the GCC Installation page</a>
   2007  1.6    mrg </p>
   2008  1.1    mrg 
   2009  1.1    mrg 
   2010  1.1    mrg 
   2011  1.3  skrll 
   2012  1.3  skrll 
   2013  1.3  skrll 
   2014  1.3  skrll 
   2015  1.3  skrll 
   2016  1.3  skrll 
   2017  1.1    mrg 
   2018  1.1    mrg 
   2019  1.6    mrg </body>
   2020  1.6    mrg </html>
   2021