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1<html lang="en"> 2<head> 3<title>Installing GCC: Configuration</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="Installing GCC: Configuration"> 6<meta name="generator" content="makeinfo 4.12"> 7<link title="Top" rel="top" href="#Top"> 8<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 9<!-- 10Copyright (C) 1988-2015 Free Software Foundation, Inc. 11 12 Permission is granted to copy, distribute and/or modify this document 13under the terms of the GNU Free Documentation License, Version 1.3 or 14any later version published by the Free Software Foundation; with no 15Invariant Sections, the Front-Cover texts being (a) (see below), and 16with the Back-Cover Texts being (b) (see below). 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Copies published by the Free Software Foundation raise 27 funds for GNU development.--> 28<meta http-equiv="Content-Style-Type" content="text/css"> 29<style type="text/css"><!-- 30 pre.display { font-family:inherit } 31 pre.format { font-family:inherit } 32 pre.smalldisplay { font-family:inherit; font-size:smaller } 33 pre.smallformat { font-family:inherit; font-size:smaller } 34 pre.smallexample { font-size:smaller } 35 pre.smalllisp { font-size:smaller } 36 span.sc { font-variant:small-caps } 37 span.roman { font-family:serif; font-weight:normal; } 38 span.sansserif { font-family:sans-serif; font-weight:normal; } 39--></style> 40</head> 41<body> 42<h1 class="settitle">Installing GCC: Configuration</h1> 43<a name="index-Configuration-1"></a><a name="index-Installing-GCC_003a-Configuration-2"></a> 44Like most GNU software, GCC must be configured before it can be built. 45This document describes the recommended configuration procedure 46for both native and cross targets. 47 48 <p>We use <var>srcdir</var> to refer to the toplevel source directory for 49GCC; we use <var>objdir</var> to refer to the toplevel build/object directory. 50 51 <p>If you obtained the sources via SVN, <var>srcdir</var> must refer to the top 52<samp><span class="file">gcc</span></samp> directory, the one where the <samp><span class="file">MAINTAINERS</span></samp> file can be 53found, and not its <samp><span class="file">gcc</span></samp> subdirectory, otherwise the build will fail. 54 55 <p>If either <var>srcdir</var> or <var>objdir</var> is located on an automounted NFS 56file system, the shell's built-in <samp><span class="command">pwd</span></samp> command will return 57temporary pathnames. Using these can lead to various sorts of build 58problems. To avoid this issue, set the <samp><span class="env">PWDCMD</span></samp> environment 59variable to an automounter-aware <samp><span class="command">pwd</span></samp> command, e.g., 60<samp><span class="command">pawd</span></samp> or ‘<samp><span class="samp">amq -w</span></samp>’, during the configuration and build 61phases. 62 63 <p>First, we <strong>highly</strong> recommend that GCC be built into a 64separate directory from the sources which does <strong>not</strong> reside 65within the source tree. This is how we generally build GCC; building 66where <var>srcdir</var> == <var>objdir</var> should still work, but doesn't 67get extensive testing; building where <var>objdir</var> is a subdirectory 68of <var>srcdir</var> is unsupported. 69 70 <p>If you have previously built GCC in the same directory for a 71different target machine, do ‘<samp><span class="samp">make distclean</span></samp>’ to delete all files 72that might be invalid. One of the files this deletes is <samp><span class="file">Makefile</span></samp>; 73if ‘<samp><span class="samp">make distclean</span></samp>’ complains that <samp><span class="file">Makefile</span></samp> does not exist 74or issues a message like “don't know how to make distclean” it probably 75means that the directory is already suitably clean. However, with the 76recommended method of building in a separate <var>objdir</var>, you should 77simply use a different <var>objdir</var> for each target. 78 79 <p>Second, when configuring a native system, either <samp><span class="command">cc</span></samp> or 80<samp><span class="command">gcc</span></samp> must be in your path or you must set <samp><span class="env">CC</span></samp> in 81your environment before running configure. Otherwise the configuration 82scripts may fail. 83 84 <p>To configure GCC: 85 86<pre class="smallexample"> % mkdir <var>objdir</var> 87 % cd <var>objdir</var> 88 % <var>srcdir</var>/configure [<var>options</var>] [<var>target</var>] 89</pre> 90 <h3 class="heading"><a name="TOC0"></a>Distributor options</h3> 91 92<p>If you will be distributing binary versions of GCC, with modifications 93to the source code, you should use the options described in this 94section to make clear that your version contains modifications. 95 96 <dl> 97<dt><code>--with-pkgversion=</code><var>version</var><dd>Specify a string that identifies your package. You may wish 98to include a build number or build date. This version string will be 99included in the output of <samp><span class="command">gcc --version</span></samp>. This suffix does 100not replace the default version string, only the ‘<samp><span class="samp">GCC</span></samp>’ part. 101 102 <p>The default value is ‘<samp><span class="samp">GCC</span></samp>’. 103 104 <br><dt><code>--with-bugurl=</code><var>url</var><dd>Specify the URL that users should visit if they wish to report a bug. 105You are of course welcome to forward bugs reported to you to the FSF, 106if you determine that they are not bugs in your modifications. 107 108 <p>The default value refers to the FSF's GCC bug tracker. 109 110 </dl> 111 112<h3 class="heading"><a name="TOC1"></a>Target specification</h3> 113 114 <ul> 115<li>GCC has code to correctly determine the correct value for <var>target</var> 116for nearly all native systems. Therefore, we highly recommend you do 117not provide a configure target when configuring a native compiler. 118 119 <li><var>target</var> must be specified as <samp><span class="option">--target=</span><var>target</var></samp> 120when configuring a cross compiler; examples of valid targets would be 121m68k-elf, sh-elf, etc. 122 123 <li>Specifying just <var>target</var> instead of <samp><span class="option">--target=</span><var>target</var></samp> 124implies that the host defaults to <var>target</var>. 125</ul> 126 127<h3 class="heading"><a name="TOC2"></a>Options specification</h3> 128 129<p>Use <var>options</var> to override several configure time options for 130GCC. A list of supported <var>options</var> follows; ‘<samp><span class="samp">configure 131--help</span></samp>’ may list other options, but those not listed below may not 132work and should not normally be used. 133 134 <p>Note that each <samp><span class="option">--enable</span></samp> option has a corresponding 135<samp><span class="option">--disable</span></samp> option and that each <samp><span class="option">--with</span></samp> option has a 136corresponding <samp><span class="option">--without</span></samp> option. 137 138 <dl> 139<dt><code>--prefix=</code><var>dirname</var><dd>Specify the toplevel installation 140directory. This is the recommended way to install the tools into a directory 141other than the default. The toplevel installation directory defaults to 142<samp><span class="file">/usr/local</span></samp>. 143 144 <p>We <strong>highly</strong> recommend against <var>dirname</var> being the same or a 145subdirectory of <var>objdir</var> or vice versa. If specifying a directory 146beneath a user's home directory tree, some shells will not expand 147<var>dirname</var> correctly if it contains the ‘<samp><span class="samp">~</span></samp>’ metacharacter; use 148<samp><span class="env">$HOME</span></samp> instead. 149 150 <p>The following standard <samp><span class="command">autoconf</span></samp> options are supported. Normally you 151should not need to use these options. 152 <dl> 153<dt><code>--exec-prefix=</code><var>dirname</var><dd>Specify the toplevel installation directory for architecture-dependent 154files. The default is <samp><var>prefix</var></samp>. 155 156 <br><dt><code>--bindir=</code><var>dirname</var><dd>Specify the installation directory for the executables called by users 157(such as <samp><span class="command">gcc</span></samp> and <samp><span class="command">g++</span></samp>). The default is 158<samp><var>exec-prefix</var><span class="file">/bin</span></samp>. 159 160 <br><dt><code>--libdir=</code><var>dirname</var><dd>Specify the installation directory for object code libraries and 161internal data files of GCC. The default is <samp><var>exec-prefix</var><span class="file">/lib</span></samp>. 162 163 <br><dt><code>--libexecdir=</code><var>dirname</var><dd>Specify the installation directory for internal executables of GCC. 164The default is <samp><var>exec-prefix</var><span class="file">/libexec</span></samp>. 165 166 <br><dt><code>--with-slibdir=</code><var>dirname</var><dd>Specify the installation directory for the shared libgcc library. The 167default is <samp><var>libdir</var></samp>. 168 169 <br><dt><code>--datarootdir=</code><var>dirname</var><dd>Specify the root of the directory tree for read-only architecture-independent 170data files referenced by GCC. The default is <samp><var>prefix</var><span class="file">/share</span></samp>. 171 172 <br><dt><code>--infodir=</code><var>dirname</var><dd>Specify the installation directory for documentation in info format. 173The default is <samp><var>datarootdir</var><span class="file">/info</span></samp>. 174 175 <br><dt><code>--datadir=</code><var>dirname</var><dd>Specify the installation directory for some architecture-independent 176data files referenced by GCC. The default is <samp><var>datarootdir</var></samp>. 177 178 <br><dt><code>--docdir=</code><var>dirname</var><dd>Specify the installation directory for documentation files (other 179than Info) for GCC. The default is <samp><var>datarootdir</var><span class="file">/doc</span></samp>. 180 181 <br><dt><code>--htmldir=</code><var>dirname</var><dd>Specify the installation directory for HTML documentation files. 182The default is <samp><var>docdir</var></samp>. 183 184 <br><dt><code>--pdfdir=</code><var>dirname</var><dd>Specify the installation directory for PDF documentation files. 185The default is <samp><var>docdir</var></samp>. 186 187 <br><dt><code>--mandir=</code><var>dirname</var><dd>Specify the installation directory for manual pages. The default is 188<samp><var>datarootdir</var><span class="file">/man</span></samp>. (Note that the manual pages are only extracts 189from the full GCC manuals, which are provided in Texinfo format. The manpages 190are derived by an automatic conversion process from parts of the full 191manual.) 192 193 <br><dt><code>--with-gxx-include-dir=</code><var>dirname</var><dd>Specify 194the installation directory for G++ header files. The default depends 195on other configuration options, and differs between cross and native 196configurations. 197 198 <br><dt><code>--with-specs=</code><var>specs</var><dd>Specify additional command line driver SPECS. 199This can be useful if you need to turn on a non-standard feature by 200default without modifying the compiler's source code, for instance 201<samp><span class="option">--with-specs=%{!fcommon:%{!fno-common:-fno-common}}</span></samp>. 202See “Spec Files” in the main manual 203 204 </dl> 205 206 <br><dt><code>--program-prefix=</code><var>prefix</var><dd>GCC supports some transformations of the names of its programs when 207installing them. This option prepends <var>prefix</var> to the names of 208programs to install in <var>bindir</var> (see above). For example, specifying 209<samp><span class="option">--program-prefix=foo-</span></samp> would result in ‘<samp><span class="samp">gcc</span></samp>’ 210being installed as <samp><span class="file">/usr/local/bin/foo-gcc</span></samp>. 211 212 <br><dt><code>--program-suffix=</code><var>suffix</var><dd>Appends <var>suffix</var> to the names of programs to install in <var>bindir</var> 213(see above). For example, specifying <samp><span class="option">--program-suffix=-3.1</span></samp> 214would result in ‘<samp><span class="samp">gcc</span></samp>’ being installed as 215<samp><span class="file">/usr/local/bin/gcc-3.1</span></samp>. 216 217 <br><dt><code>--program-transform-name=</code><var>pattern</var><dd>Applies the ‘<samp><span class="samp">sed</span></samp>’ script <var>pattern</var> to be applied to the names 218of programs to install in <var>bindir</var> (see above). <var>pattern</var> has to 219consist of one or more basic ‘<samp><span class="samp">sed</span></samp>’ editing commands, separated by 220semicolons. For example, if you want the ‘<samp><span class="samp">gcc</span></samp>’ program name to be 221transformed to the installed program <samp><span class="file">/usr/local/bin/myowngcc</span></samp> and 222the ‘<samp><span class="samp">g++</span></samp>’ program name to be transformed to 223<samp><span class="file">/usr/local/bin/gspecial++</span></samp> without changing other program names, 224you could use the pattern 225<samp><span class="option">--program-transform-name='s/^gcc$/myowngcc/; s/^g++$/gspecial++/'</span></samp> 226to achieve this effect. 227 228 <p>All three options can be combined and used together, resulting in more 229complex conversion patterns. As a basic rule, <var>prefix</var> (and 230<var>suffix</var>) are prepended (appended) before further transformations 231can happen with a special transformation script <var>pattern</var>. 232 233 <p>As currently implemented, this option only takes effect for native 234builds; cross compiler binaries' names are not transformed even when a 235transformation is explicitly asked for by one of these options. 236 237 <p>For native builds, some of the installed programs are also installed 238with the target alias in front of their name, as in 239‘<samp><span class="samp">i686-pc-linux-gnu-gcc</span></samp>’. All of the above transformations happen 240before the target alias is prepended to the name—so, specifying 241<samp><span class="option">--program-prefix=foo-</span></samp> and <samp><span class="option">program-suffix=-3.1</span></samp>, the 242resulting binary would be installed as 243<samp><span class="file">/usr/local/bin/i686-pc-linux-gnu-foo-gcc-3.1</span></samp>. 244 245 <p>As a last shortcoming, none of the installed Ada programs are 246transformed yet, which will be fixed in some time. 247 248 <br><dt><code>--with-local-prefix=</code><var>dirname</var><dd>Specify the 249installation directory for local include files. The default is 250<samp><span class="file">/usr/local</span></samp>. Specify this option if you want the compiler to 251search directory <samp><var>dirname</var><span class="file">/include</span></samp> for locally installed 252header files <em>instead</em> of <samp><span class="file">/usr/local/include</span></samp>. 253 254 <p>You should specify <samp><span class="option">--with-local-prefix</span></samp> <strong>only</strong> if your 255site has a different convention (not <samp><span class="file">/usr/local</span></samp>) for where to put 256site-specific files. 257 258 <p>The default value for <samp><span class="option">--with-local-prefix</span></samp> is <samp><span class="file">/usr/local</span></samp> 259regardless of the value of <samp><span class="option">--prefix</span></samp>. Specifying 260<samp><span class="option">--prefix</span></samp> has no effect on which directory GCC searches for 261local header files. This may seem counterintuitive, but actually it is 262logical. 263 264 <p>The purpose of <samp><span class="option">--prefix</span></samp> is to specify where to <em>install 265GCC</em>. The local header files in <samp><span class="file">/usr/local/include</span></samp>—if you put 266any in that directory—are not part of GCC. They are part of other 267programs—perhaps many others. (GCC installs its own header files in 268another directory which is based on the <samp><span class="option">--prefix</span></samp> value.) 269 270 <p>Both the local-prefix include directory and the GCC-prefix include 271directory are part of GCC's “system include” directories. Although these 272two directories are not fixed, they need to be searched in the proper 273order for the correct processing of the include_next directive. The 274local-prefix include directory is searched before the GCC-prefix 275include directory. Another characteristic of system include directories 276is that pedantic warnings are turned off for headers in these directories. 277 278 <p>Some autoconf macros add <samp><span class="option">-I </span><var>directory</var></samp> options to the 279compiler command line, to ensure that directories containing installed 280packages' headers are searched. When <var>directory</var> is one of GCC's 281system include directories, GCC will ignore the option so that system 282directories continue to be processed in the correct order. This 283may result in a search order different from what was specified but the 284directory will still be searched. 285 286 <p>GCC automatically searches for ordinary libraries using 287<samp><span class="env">GCC_EXEC_PREFIX</span></samp>. Thus, when the same installation prefix is 288used for both GCC and packages, GCC will automatically search for 289both headers and libraries. This provides a configuration that is 290easy to use. GCC behaves in a manner similar to that when it is 291installed as a system compiler in <samp><span class="file">/usr</span></samp>. 292 293 <p>Sites that need to install multiple versions of GCC may not want to 294use the above simple configuration. It is possible to use the 295<samp><span class="option">--program-prefix</span></samp>, <samp><span class="option">--program-suffix</span></samp> and 296<samp><span class="option">--program-transform-name</span></samp> options to install multiple versions 297into a single directory, but it may be simpler to use different prefixes 298and the <samp><span class="option">--with-local-prefix</span></samp> option to specify the location of the 299site-specific files for each version. It will then be necessary for 300users to specify explicitly the location of local site libraries 301(e.g., with <samp><span class="env">LIBRARY_PATH</span></samp>). 302 303 <p>The same value can be used for both <samp><span class="option">--with-local-prefix</span></samp> and 304<samp><span class="option">--prefix</span></samp> provided it is not <samp><span class="file">/usr</span></samp>. This can be used 305to avoid the default search of <samp><span class="file">/usr/local/include</span></samp>. 306 307 <p><strong>Do not</strong> specify <samp><span class="file">/usr</span></samp> as the <samp><span class="option">--with-local-prefix</span></samp>! 308The directory you use for <samp><span class="option">--with-local-prefix</span></samp> <strong>must not</strong> 309contain any of the system's standard header files. If it did contain 310them, certain programs would be miscompiled (including GNU Emacs, on 311certain targets), because this would override and nullify the header 312file corrections made by the <samp><span class="command">fixincludes</span></samp> script. 313 314 <p>Indications are that people who use this option use it based on mistaken 315ideas of what it is for. People use it as if it specified where to 316install part of GCC. Perhaps they make this assumption because 317installing GCC creates the directory. 318 319 <br><dt><code>--with-native-system-header-dir=</code><var>dirname</var><dd>Specifies that <var>dirname</var> is the directory that contains native system 320header files, rather than <samp><span class="file">/usr/include</span></samp>. This option is most useful 321if you are creating a compiler that should be isolated from the system 322as much as possible. It is most commonly used with the 323<samp><span class="option">--with-sysroot</span></samp> option and will cause GCC to search 324<var>dirname</var> inside the system root specified by that option. 325 326 <br><dt><code>--enable-shared[=</code><var>package</var><code>[,...]]</code><dd>Build shared versions of libraries, if shared libraries are supported on 327the target platform. Unlike GCC 2.95.x and earlier, shared libraries 328are enabled by default on all platforms that support shared libraries. 329 330 <p>If a list of packages is given as an argument, build shared libraries 331only for the listed packages. For other packages, only static libraries 332will be built. Package names currently recognized in the GCC tree are 333‘<samp><span class="samp">libgcc</span></samp>’ (also known as ‘<samp><span class="samp">gcc</span></samp>’), ‘<samp><span class="samp">libstdc++</span></samp>’ (not 334‘<samp><span class="samp">libstdc++-v3</span></samp>’), ‘<samp><span class="samp">libffi</span></samp>’, ‘<samp><span class="samp">zlib</span></samp>’, ‘<samp><span class="samp">boehm-gc</span></samp>’, 335‘<samp><span class="samp">ada</span></samp>’, ‘<samp><span class="samp">libada</span></samp>’, ‘<samp><span class="samp">libjava</span></samp>’, ‘<samp><span class="samp">libgo</span></samp>’, and ‘<samp><span class="samp">libobjc</span></samp>’. 336Note ‘<samp><span class="samp">libiberty</span></samp>’ does not support shared libraries at all. 337 338 <p>Use <samp><span class="option">--disable-shared</span></samp> to build only static libraries. Note that 339<samp><span class="option">--disable-shared</span></samp> does not accept a list of package names as 340argument, only <samp><span class="option">--enable-shared</span></samp> does. 341 342 <br><dt><code><a name="with_002dgnu_002das"></a>--with-gnu-as</code><dd>Specify that the compiler should assume that the 343assembler it finds is the GNU assembler. However, this does not modify 344the rules to find an assembler and will result in confusion if the 345assembler found is not actually the GNU assembler. (Confusion may also 346result if the compiler finds the GNU assembler but has not been 347configured with <samp><span class="option">--with-gnu-as</span></samp>.) If you have more than one 348assembler installed on your system, you may want to use this option in 349connection with <samp><span class="option">--with-as=</span><var>pathname</var></samp> or 350<samp><span class="option">--with-build-time-tools=</span><var>pathname</var></samp>. 351 352 <p>The following systems are the only ones where it makes a difference 353whether you use the GNU assembler. On any other system, 354<samp><span class="option">--with-gnu-as</span></samp> has no effect. 355 356 <ul> 357<li>‘<samp><span class="samp">hppa1.0-</span><var>any</var><span class="samp">-</span><var>any</var></samp>’ 358<li>‘<samp><span class="samp">hppa1.1-</span><var>any</var><span class="samp">-</span><var>any</var></samp>’ 359<li>‘<samp><span class="samp">sparc-sun-solaris2.</span><var>any</var></samp>’ 360<li>‘<samp><span class="samp">sparc64-</span><var>any</var><span class="samp">-solaris2.</span><var>any</var></samp>’ 361</ul> 362 363 <br><dt><code><a name="with_002das"></a>--with-as=</code><var>pathname</var><dd>Specify that the compiler should use the assembler pointed to by 364<var>pathname</var>, rather than the one found by the standard rules to find 365an assembler, which are: 366 <ul> 367<li>Unless GCC is being built with a cross compiler, check the 368<samp><var>libexec</var><span class="file">/gcc/</span><var>target</var><span class="file">/</span><var>version</var></samp> directory. 369<var>libexec</var> defaults to <samp><var>exec-prefix</var><span class="file">/libexec</span></samp>; 370<var>exec-prefix</var> defaults to <var>prefix</var>, which 371defaults to <samp><span class="file">/usr/local</span></samp> unless overridden by the 372<samp><span class="option">--prefix=</span><var>pathname</var></samp> switch described above. <var>target</var> 373is the target system triple, such as ‘<samp><span class="samp">sparc-sun-solaris2.7</span></samp>’, and 374<var>version</var> denotes the GCC version, such as 3.0. 375 376 <li>If the target system is the same that you are building on, check 377operating system specific directories (e.g. <samp><span class="file">/usr/ccs/bin</span></samp> on 378Sun Solaris 2). 379 380 <li>Check in the <samp><span class="env">PATH</span></samp> for a tool whose name is prefixed by the 381target system triple. 382 383 <li>Check in the <samp><span class="env">PATH</span></samp> for a tool whose name is not prefixed by the 384target system triple, if the host and target system triple are 385the same (in other words, we use a host tool if it can be used for 386the target as well). 387</ul> 388 389 <p>You may want to use <samp><span class="option">--with-as</span></samp> if no assembler 390is installed in the directories listed above, or if you have multiple 391assemblers installed and want to choose one that is not found by the 392above rules. 393 394 <br><dt><code><a name="with_002dgnu_002dld"></a>--with-gnu-ld</code><dd>Same as <a href="#with-gnu-as"><samp><span class="option">--with-gnu-as</span></samp></a> 395but for the linker. 396 397 <br><dt><code>--with-ld=</code><var>pathname</var><dd>Same as <a href="#with-as"><samp><span class="option">--with-as</span></samp></a> 398but for the linker. 399 400 <br><dt><code>--with-stabs</code><dd>Specify that stabs debugging 401information should be used instead of whatever format the host normally 402uses. Normally GCC uses the same debug format as the host system. 403 404 <p>On MIPS based systems and on Alphas, you must specify whether you want 405GCC to create the normal ECOFF debugging format, or to use BSD-style 406stabs passed through the ECOFF symbol table. The normal ECOFF debug 407format cannot fully handle languages other than C. BSD stabs format can 408handle other languages, but it only works with the GNU debugger GDB. 409 410 <p>Normally, GCC uses the ECOFF debugging format by default; if you 411prefer BSD stabs, specify <samp><span class="option">--with-stabs</span></samp> when you configure GCC. 412 413 <p>No matter which default you choose when you configure GCC, the user 414can use the <samp><span class="option">-gcoff</span></samp> and <samp><span class="option">-gstabs+</span></samp> options to specify explicitly 415the debug format for a particular compilation. 416 417 <p><samp><span class="option">--with-stabs</span></samp> is meaningful on the ISC system on the 386, also, if 418<samp><span class="option">--with-gas</span></samp> is used. It selects use of stabs debugging 419information embedded in COFF output. This kind of debugging information 420supports C++ well; ordinary COFF debugging information does not. 421 422 <p><samp><span class="option">--with-stabs</span></samp> is also meaningful on 386 systems running SVR4. It 423selects use of stabs debugging information embedded in ELF output. The 424C++ compiler currently (2.6.0) does not support the DWARF debugging 425information normally used on 386 SVR4 platforms; stabs provide a 426workable alternative. This requires gas and gdb, as the normal SVR4 427tools can not generate or interpret stabs. 428 429 <br><dt><code>--with-tls=</code><var>dialect</var><dd>Specify the default TLS dialect, for systems were there is a choice. 430For ARM targets, possible values for <var>dialect</var> are <code>gnu</code> or 431<code>gnu2</code>, which select between the original GNU dialect and the GNU TLS 432descriptor-based dialect. 433 434 <br><dt><code>--enable-multiarch</code><dd>Specify whether to enable or disable multiarch support. The default is 435to check for glibc start files in a multiarch location, and enable it 436if the files are found. The auto detection is enabled for native builds, 437and for cross builds configured with <samp><span class="option">--with-sysroot</span></samp>, and without 438<samp><span class="option">--with-native-system-header-dir</span></samp>. 439More documentation about multiarch can be found at 440<a href="http://wiki.debian.org/Multiarch">http://wiki.debian.org/Multiarch</a>. 441 442 <br><dt><code>--disable-multilib</code><dd>Specify that multiple target 443libraries to support different target variants, calling 444conventions, etc. should not be built. The default is to build a 445predefined set of them. 446 447 <p>Some targets provide finer-grained control over which multilibs are built 448(e.g., <samp><span class="option">--disable-softfloat</span></samp>): 449 <dl> 450<dt><code>arm-*-*</code><dd>fpu, 26bit, underscore, interwork, biendian, nofmult. 451 452 <br><dt><code>m68*-*-*</code><dd>softfloat, m68881, m68000, m68020. 453 454 <br><dt><code>mips*-*-*</code><dd>single-float, biendian, softfloat. 455 456 <br><dt><code>powerpc*-*-*, rs6000*-*-*</code><dd>aix64, pthread, softfloat, powercpu, powerpccpu, powerpcos, biendian, 457sysv, aix. 458 459 </dl> 460 461 <br><dt><code>--with-multilib-list=</code><var>list</var><dt><code>--without-multilib-list</code><dd>Specify what multilibs to build. 462Currently only implemented for sh*-*-* and x86-64-*-linux*. 463 464 <dl> 465<dt><code>sh*-*-*</code><dd><var>list</var> is a comma separated list of CPU names. These must be of the 466form <code>sh*</code> or <code>m*</code> (in which case they match the compiler option 467for that processor). The list should not contain any endian options - 468these are handled by <samp><span class="option">--with-endian</span></samp>. 469 470 <p>If <var>list</var> is empty, then there will be no multilibs for extra 471processors. The multilib for the secondary endian remains enabled. 472 473 <p>As a special case, if an entry in the list starts with a <code>!</code> 474(exclamation point), then it is added to the list of excluded multilibs. 475Entries of this sort should be compatible with ‘<samp><span class="samp">MULTILIB_EXCLUDES</span></samp>’ 476(once the leading <code>!</code> has been stripped). 477 478 <p>If <samp><span class="option">--with-multilib-list</span></samp> is not given, then a default set of 479multilibs is selected based on the value of <samp><span class="option">--target</span></samp>. This is 480usually the complete set of libraries, but some targets imply a more 481specialized subset. 482 483 <p>Example 1: to configure a compiler for SH4A only, but supporting both 484endians, with little endian being the default: 485 <pre class="smallexample"> --with-cpu=sh4a --with-endian=little,big --with-multilib-list= 486</pre> 487 <p>Example 2: to configure a compiler for both SH4A and SH4AL-DSP, but with 488only little endian SH4AL: 489 <pre class="smallexample"> --with-cpu=sh4a --with-endian=little,big \ 490 --with-multilib-list=sh4al,!mb/m4al 491</pre> 492 <br><dt><code>x86-64-*-linux*</code><dd><var>list</var> is a comma separated list of <code>m32</code>, <code>m64</code> and 493<code>mx32</code> to enable 32-bit, 64-bit and x32 run-time libraries, 494respectively. If <var>list</var> is empty, then there will be no multilibs 495and only the default run-time library will be enabled. 496 497 <p>If <samp><span class="option">--with-multilib-list</span></samp> is not given, then only 32-bit and 49864-bit run-time libraries will be enabled. 499</dl> 500 501 <br><dt><code>--with-endian=</code><var>endians</var><dd>Specify what endians to use. 502Currently only implemented for sh*-*-*. 503 504 <p><var>endians</var> may be one of the following: 505 <dl> 506<dt><code>big</code><dd>Use big endian exclusively. 507<br><dt><code>little</code><dd>Use little endian exclusively. 508<br><dt><code>big,little</code><dd>Use big endian by default. Provide a multilib for little endian. 509<br><dt><code>little,big</code><dd>Use little endian by default. Provide a multilib for big endian. 510</dl> 511 512 <br><dt><code>--enable-threads</code><dd>Specify that the target 513supports threads. This affects the Objective-C compiler and runtime 514library, and exception handling for other languages like C++ and Java. 515On some systems, this is the default. 516 517 <p>In general, the best (and, in many cases, the only known) threading 518model available will be configured for use. Beware that on some 519systems, GCC has not been taught what threading models are generally 520available for the system. In this case, <samp><span class="option">--enable-threads</span></samp> is an 521alias for <samp><span class="option">--enable-threads=single</span></samp>. 522 523 <br><dt><code>--disable-threads</code><dd>Specify that threading support should be disabled for the system. 524This is an alias for <samp><span class="option">--enable-threads=single</span></samp>. 525 526 <br><dt><code>--enable-threads=</code><var>lib</var><dd>Specify that 527<var>lib</var> is the thread support library. This affects the Objective-C 528compiler and runtime library, and exception handling for other languages 529like C++ and Java. The possibilities for <var>lib</var> are: 530 531 <dl> 532<dt><code>aix</code><dd>AIX thread support. 533<br><dt><code>dce</code><dd>DCE thread support. 534<br><dt><code>lynx</code><dd>LynxOS thread support. 535<br><dt><code>mipssde</code><dd>MIPS SDE thread support. 536<br><dt><code>no</code><dd>This is an alias for ‘<samp><span class="samp">single</span></samp>’. 537<br><dt><code>posix</code><dd>Generic POSIX/Unix98 thread support. 538<br><dt><code>rtems</code><dd>RTEMS thread support. 539<br><dt><code>single</code><dd>Disable thread support, should work for all platforms. 540<br><dt><code>tpf</code><dd>TPF thread support. 541<br><dt><code>vxworks</code><dd>VxWorks thread support. 542<br><dt><code>win32</code><dd>Microsoft Win32 API thread support. 543</dl> 544 545 <br><dt><code>--enable-tls</code><dd>Specify that the target supports TLS (Thread Local Storage). Usually 546configure can correctly determine if TLS is supported. In cases where 547it guesses incorrectly, TLS can be explicitly enabled or disabled with 548<samp><span class="option">--enable-tls</span></samp> or <samp><span class="option">--disable-tls</span></samp>. This can happen if 549the assembler supports TLS but the C library does not, or if the 550assumptions made by the configure test are incorrect. 551 552 <br><dt><code>--disable-tls</code><dd>Specify that the target does not support TLS. 553This is an alias for <samp><span class="option">--enable-tls=no</span></samp>. 554 555 <br><dt><code>--with-cpu=</code><var>cpu</var><dt><code>--with-cpu-32=</code><var>cpu</var><dt><code>--with-cpu-64=</code><var>cpu</var><dd>Specify which cpu variant the compiler should generate code for by default. 556<var>cpu</var> will be used as the default value of the <samp><span class="option">-mcpu=</span></samp> switch. 557This option is only supported on some targets, including ARM, i386, M68k, 558PowerPC, and SPARC. The <samp><span class="option">--with-cpu-32</span></samp> and 559<samp><span class="option">--with-cpu-64</span></samp> options specify separate default CPUs for 56032-bit and 64-bit modes; these options are only supported for i386, 561x86-64 and PowerPC. 562 563 <br><dt><code>--with-schedule=</code><var>cpu</var><dt><code>--with-arch=</code><var>cpu</var><dt><code>--with-arch-32=</code><var>cpu</var><dt><code>--with-arch-64=</code><var>cpu</var><dt><code>--with-tune=</code><var>cpu</var><dt><code>--with-tune-32=</code><var>cpu</var><dt><code>--with-tune-64=</code><var>cpu</var><dt><code>--with-abi=</code><var>abi</var><dt><code>--with-fpu=</code><var>type</var><dt><code>--with-float=</code><var>type</var><dd>These configure options provide default values for the <samp><span class="option">-mschedule=</span></samp>, 564<samp><span class="option">-march=</span></samp>, <samp><span class="option">-mtune=</span></samp>, <samp><span class="option">-mabi=</span></samp>, and <samp><span class="option">-mfpu=</span></samp> 565options and for <samp><span class="option">-mhard-float</span></samp> or <samp><span class="option">-msoft-float</span></samp>. As with 566<samp><span class="option">--with-cpu</span></samp>, which switches will be accepted and acceptable values 567of the arguments depend on the target. 568 569 <br><dt><code>--with-mode=</code><var>mode</var><dd>Specify if the compiler should default to <samp><span class="option">-marm</span></samp> or <samp><span class="option">-mthumb</span></samp>. 570This option is only supported on ARM targets. 571 572 <br><dt><code>--with-stack-offset=</code><var>num</var><dd>This option sets the default for the -mstack-offset=<var>num</var> option, 573and will thus generally also control the setting of this option for 574libraries. This option is only supported on Epiphany targets. 575 576 <br><dt><code>--with-fpmath=</code><var>isa</var><dd>This options sets <samp><span class="option">-mfpmath=sse</span></samp> by default and specifies the default 577ISA for floating-point arithmetics. You can select either ‘<samp><span class="samp">sse</span></samp>’ which 578enables <samp><span class="option">-msse2</span></samp> or ‘<samp><span class="samp">avx</span></samp>’ which enables <samp><span class="option">-mavx</span></samp> by default. 579This option is only supported on i386 and x86-64 targets. 580 581 <br><dt><code>--with-divide=</code><var>type</var><dd>Specify how the compiler should generate code for checking for 582division by zero. This option is only supported on the MIPS target. 583The possibilities for <var>type</var> are: 584 <dl> 585<dt><code>traps</code><dd>Division by zero checks use conditional traps (this is the default on 586systems that support conditional traps). 587<br><dt><code>breaks</code><dd>Division by zero checks use the break instruction. 588</dl> 589 590 <!-- If you make -with-llsc the default for additional targets, --> 591 <!-- update the -with-llsc description in the MIPS section below. --> 592 <br><dt><code>--with-llsc</code><dd>On MIPS targets, make <samp><span class="option">-mllsc</span></samp> the default when no 593<samp><span class="option">-mno-llsc</span></samp> option is passed. This is the default for 594Linux-based targets, as the kernel will emulate them if the ISA does 595not provide them. 596 597 <br><dt><code>--without-llsc</code><dd>On MIPS targets, make <samp><span class="option">-mno-llsc</span></samp> the default when no 598<samp><span class="option">-mllsc</span></samp> option is passed. 599 600 <br><dt><code>--with-synci</code><dd>On MIPS targets, make <samp><span class="option">-msynci</span></samp> the default when no 601<samp><span class="option">-mno-synci</span></samp> option is passed. 602 603 <br><dt><code>--without-synci</code><dd>On MIPS targets, make <samp><span class="option">-mno-synci</span></samp> the default when no 604<samp><span class="option">-msynci</span></samp> option is passed. This is the default. 605 606 <br><dt><code>--with-mips-plt</code><dd>On MIPS targets, make use of copy relocations and PLTs. 607These features are extensions to the traditional 608SVR4-based MIPS ABIs and require support from GNU binutils 609and the runtime C library. 610 611 <br><dt><code>--enable-__cxa_atexit</code><dd>Define if you want to use __cxa_atexit, rather than atexit, to 612register C++ destructors for local statics and global objects. 613This is essential for fully standards-compliant handling of 614destructors, but requires __cxa_atexit in libc. This option is currently 615only available on systems with GNU libc. When enabled, this will cause 616<samp><span class="option">-fuse-cxa-atexit</span></samp> to be passed by default. 617 618 <br><dt><code>--enable-gnu-indirect-function</code><dd>Define if you want to enable the <code>ifunc</code> attribute. This option is 619currently only available on systems with GNU libc on certain targets. 620 621 <br><dt><code>--enable-target-optspace</code><dd>Specify that target 622libraries should be optimized for code space instead of code speed. 623This is the default for the m32r platform. 624 625 <br><dt><code>--with-cpp-install-dir=</code><var>dirname</var><dd>Specify that the user visible <samp><span class="command">cpp</span></samp> program should be installed 626in <samp><var>prefix</var><span class="file">/</span><var>dirname</var><span class="file">/cpp</span></samp>, in addition to <var>bindir</var>. 627 628 <br><dt><code>--enable-comdat</code><dd>Enable COMDAT group support. This is primarily used to override the 629automatically detected value. 630 631 <br><dt><code>--enable-initfini-array</code><dd>Force the use of sections <code>.init_array</code> and <code>.fini_array</code> 632(instead of <code>.init</code> and <code>.fini</code>) for constructors and 633destructors. Option <samp><span class="option">--disable-initfini-array</span></samp> has the 634opposite effect. If neither option is specified, the configure script 635will try to guess whether the <code>.init_array</code> and 636<code>.fini_array</code> sections are supported and, if they are, use them. 637 638 <br><dt><code>--enable-maintainer-mode</code><dd>The build rules that regenerate the Autoconf and Automake output files as 639well as the GCC master message catalog <samp><span class="file">gcc.pot</span></samp> are normally 640disabled. This is because it can only be rebuilt if the complete source 641tree is present. If you have changed the sources and want to rebuild the 642catalog, configuring with <samp><span class="option">--enable-maintainer-mode</span></samp> will enable 643this. Note that you need a recent version of the <code>gettext</code> tools 644to do so. 645 646 <br><dt><code>--disable-bootstrap</code><dd>For a native build, the default configuration is to perform 647a 3-stage bootstrap of the compiler when ‘<samp><span class="samp">make</span></samp>’ is invoked, 648testing that GCC can compile itself correctly. If you want to disable 649this process, you can configure with <samp><span class="option">--disable-bootstrap</span></samp>. 650 651 <br><dt><code>--enable-bootstrap</code><dd>In special cases, you may want to perform a 3-stage build 652even if the target and host triplets are different. 653This is possible when the host can run code compiled for 654the target (e.g. host is i686-linux, target is i486-linux). 655Starting from GCC 4.2, to do this you have to configure explicitly 656with <samp><span class="option">--enable-bootstrap</span></samp>. 657 658 <br><dt><code>--enable-generated-files-in-srcdir</code><dd>Neither the .c and .h files that are generated from Bison and flex nor the 659info manuals and man pages that are built from the .texi files are present 660in the SVN development tree. When building GCC from that development tree, 661or from one of our snapshots, those generated files are placed in your 662build directory, which allows for the source to be in a readonly 663directory. 664 665 <p>If you configure with <samp><span class="option">--enable-generated-files-in-srcdir</span></samp> then those 666generated files will go into the source directory. This is mainly intended 667for generating release or prerelease tarballs of the GCC sources, since it 668is not a requirement that the users of source releases to have flex, Bison, 669or makeinfo. 670 671 <br><dt><code>--enable-version-specific-runtime-libs</code><dd>Specify 672that runtime libraries should be installed in the compiler specific 673subdirectory (<samp><var>libdir</var><span class="file">/gcc</span></samp>) rather than the usual places. In 674addition, ‘<samp><span class="samp">libstdc++</span></samp>’'s include files will be installed into 675<samp><var>libdir</var></samp> unless you overruled it by using 676<samp><span class="option">--with-gxx-include-dir=</span><var>dirname</var></samp>. Using this option is 677particularly useful if you intend to use several versions of GCC in 678parallel. This is currently supported by ‘<samp><span class="samp">libgfortran</span></samp>’, 679‘<samp><span class="samp">libjava</span></samp>’, ‘<samp><span class="samp">libmudflap</span></samp>’, ‘<samp><span class="samp">libstdc++</span></samp>’, and ‘<samp><span class="samp">libobjc</span></samp>’. 680 681 <br><dt><code>--enable-languages=</code><var>lang1</var><code>,</code><var>lang2</var><code>,...</code><dd>Specify that only a particular subset of compilers and 682their runtime libraries should be built. For a list of valid values for 683<var>langN</var> you can issue the following command in the 684<samp><span class="file">gcc</span></samp> directory of your GCC source tree:<br> 685 <pre class="smallexample"> grep language= */config-lang.in 686</pre> 687 <p>Currently, you can use any of the following: 688<code>all</code>, <code>ada</code>, <code>c</code>, <code>c++</code>, <code>fortran</code>, 689<code>go</code>, <code>java</code>, <code>objc</code>, <code>obj-c++</code>. 690Building the Ada compiler has special requirements, see below. 691If you do not pass this flag, or specify the option <code>all</code>, then all 692default languages available in the <samp><span class="file">gcc</span></samp> sub-tree will be configured. 693Ada, Go and Objective-C++ are not default languages; the rest are. 694 695 <br><dt><code>--enable-stage1-languages=</code><var>lang1</var><code>,</code><var>lang2</var><code>,...</code><dd>Specify that a particular subset of compilers and their runtime 696libraries should be built with the system C compiler during stage 1 of 697the bootstrap process, rather than only in later stages with the 698bootstrapped C compiler. The list of valid values is the same as for 699<samp><span class="option">--enable-languages</span></samp>, and the option <code>all</code> will select all 700of the languages enabled by <samp><span class="option">--enable-languages</span></samp>. This option is 701primarily useful for GCC development; for instance, when a development 702version of the compiler cannot bootstrap due to compiler bugs, or when 703one is debugging front ends other than the C front end. When this 704option is used, one can then build the target libraries for the 705specified languages with the stage-1 compiler by using <samp><span class="command">make 706stage1-bubble all-target</span></samp>, or run the testsuite on the stage-1 compiler 707for the specified languages using <samp><span class="command">make stage1-start check-gcc</span></samp>. 708 709 <br><dt><code>--disable-libada</code><dd>Specify that the run-time libraries and tools used by GNAT should not 710be built. This can be useful for debugging, or for compatibility with 711previous Ada build procedures, when it was required to explicitly 712do a ‘<samp><span class="samp">make -C gcc gnatlib_and_tools</span></samp>’. 713 714 <br><dt><code>--disable-libssp</code><dd>Specify that the run-time libraries for stack smashing protection 715should not be built. 716 717 <br><dt><code>--disable-libquadmath</code><dd>Specify that the GCC quad-precision math library should not be built. 718On some systems, the library is required to be linkable when building 719the Fortran front end, unless <samp><span class="option">--disable-libquadmath-support</span></samp> 720is used. 721 722 <br><dt><code>--disable-libquadmath-support</code><dd>Specify that the Fortran front end and <code>libgfortran</code> do not add 723support for <code>libquadmath</code> on systems supporting it. 724 725 <br><dt><code>--disable-libgomp</code><dd>Specify that the run-time libraries used by GOMP should not be built. 726 727 <br><dt><code>--with-dwarf2</code><dd>Specify that the compiler should 728use DWARF 2 debugging information as the default. 729 730 <br><dt><code>--enable-targets=all</code><dt><code>--enable-targets=</code><var>target_list</var><dd>Some GCC targets, e.g. powerpc64-linux, build bi-arch compilers. 731These are compilers that are able to generate either 64-bit or 32-bit 732code. Typically, the corresponding 32-bit target, e.g. 733powerpc-linux for powerpc64-linux, only generates 32-bit code. This 734option enables the 32-bit target to be a bi-arch compiler, which is 735useful when you want a bi-arch compiler that defaults to 32-bit, and 736you are building a bi-arch or multi-arch binutils in a combined tree. 737On mips-linux, this will build a tri-arch compiler (ABI o32/n32/64), 738defaulted to o32. 739Currently, this option only affects sparc-linux, powerpc-linux, x86-linux, 740mips-linux and s390-linux. 741 742 <br><dt><code>--enable-secureplt</code><dd>This option enables <samp><span class="option">-msecure-plt</span></samp> by default for powerpc-linux. 743See “RS/6000 and PowerPC Options” in the main manual 744 745 <br><dt><code>--enable-cld</code><dd>This option enables <samp><span class="option">-mcld</span></samp> by default for 32-bit x86 targets. 746See “i386 and x86-64 Options” in the main manual 747 748 <br><dt><code>--enable-win32-registry</code><dt><code>--enable-win32-registry=</code><var>key</var><dt><code>--disable-win32-registry</code><dd>The <samp><span class="option">--enable-win32-registry</span></samp> option enables Microsoft Windows-hosted GCC 749to look up installations paths in the registry using the following key: 750 751 <pre class="smallexample"> <code>HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\</code><var>key</var> 752</pre> 753 <p><var>key</var> defaults to GCC version number, and can be overridden by the 754<samp><span class="option">--enable-win32-registry=</span><var>key</var></samp> option. Vendors and distributors 755who use custom installers are encouraged to provide a different key, 756perhaps one comprised of vendor name and GCC version number, to 757avoid conflict with existing installations. This feature is enabled 758by default, and can be disabled by <samp><span class="option">--disable-win32-registry</span></samp> 759option. This option has no effect on the other hosts. 760 761 <br><dt><code>--nfp</code><dd>Specify that the machine does not have a floating point unit. This 762option only applies to ‘<samp><span class="samp">m68k-sun-sunos</span><var>n</var></samp>’. On any other 763system, <samp><span class="option">--nfp</span></samp> has no effect. 764 765 <br><dt><code>--enable-werror</code><dt><code>--disable-werror</code><dt><code>--enable-werror=yes</code><dt><code>--enable-werror=no</code><dd>When you specify this option, it controls whether certain files in the 766compiler are built with <samp><span class="option">-Werror</span></samp> in bootstrap stage2 and later. 767If you don't specify it, <samp><span class="option">-Werror</span></samp> is turned on for the main 768development trunk. However it defaults to off for release branches and 769final releases. The specific files which get <samp><span class="option">-Werror</span></samp> are 770controlled by the Makefiles. 771 772 <br><dt><code>--enable-checking</code><dt><code>--enable-checking=</code><var>list</var><dd>When you specify this option, the compiler is built to perform internal 773consistency checks of the requested complexity. This does not change the 774generated code, but adds error checking within the compiler. This will 775slow down the compiler and may only work properly if you are building 776the compiler with GCC. This is ‘<samp><span class="samp">yes</span></samp>’ by default when building 777from SVN or snapshots, but ‘<samp><span class="samp">release</span></samp>’ for releases. The default 778for building the stage1 compiler is ‘<samp><span class="samp">yes</span></samp>’. More control 779over the checks may be had by specifying <var>list</var>. The categories of 780checks available are ‘<samp><span class="samp">yes</span></samp>’ (most common checks 781‘<samp><span class="samp">assert,misc,tree,gc,rtlflag,runtime</span></samp>’), ‘<samp><span class="samp">no</span></samp>’ (no checks at 782all), ‘<samp><span class="samp">all</span></samp>’ (all but ‘<samp><span class="samp">valgrind</span></samp>’), ‘<samp><span class="samp">release</span></samp>’ (cheapest 783checks ‘<samp><span class="samp">assert,runtime</span></samp>’) or ‘<samp><span class="samp">none</span></samp>’ (same as ‘<samp><span class="samp">no</span></samp>’). 784Individual checks can be enabled with these flags ‘<samp><span class="samp">assert</span></samp>’, 785‘<samp><span class="samp">df</span></samp>’, ‘<samp><span class="samp">fold</span></samp>’, ‘<samp><span class="samp">gc</span></samp>’, ‘<samp><span class="samp">gcac</span></samp>’ ‘<samp><span class="samp">misc</span></samp>’, ‘<samp><span class="samp">rtl</span></samp>’, 786‘<samp><span class="samp">rtlflag</span></samp>’, ‘<samp><span class="samp">runtime</span></samp>’, ‘<samp><span class="samp">tree</span></samp>’, and ‘<samp><span class="samp">valgrind</span></samp>’. 787 788 <p>The ‘<samp><span class="samp">valgrind</span></samp>’ check requires the external <samp><span class="command">valgrind</span></samp> 789simulator, available from <a href="http://valgrind.org/">http://valgrind.org/</a>. The 790‘<samp><span class="samp">df</span></samp>’, ‘<samp><span class="samp">rtl</span></samp>’, ‘<samp><span class="samp">gcac</span></samp>’ and ‘<samp><span class="samp">valgrind</span></samp>’ checks are very expensive. 791To disable all checking, ‘<samp><span class="samp">--disable-checking</span></samp>’ or 792‘<samp><span class="samp">--enable-checking=none</span></samp>’ must be explicitly requested. Disabling 793assertions will make the compiler and runtime slightly faster but 794increase the risk of undetected internal errors causing wrong code to be 795generated. 796 797 <br><dt><code>--disable-stage1-checking</code><dt><code>--enable-stage1-checking</code><dt><code>--enable-stage1-checking=</code><var>list</var><dd>If no <samp><span class="option">--enable-checking</span></samp> option is specified the stage1 798compiler will be built with ‘<samp><span class="samp">yes</span></samp>’ checking enabled, otherwise 799the stage1 checking flags are the same as specified by 800<samp><span class="option">--enable-checking</span></samp>. To build the stage1 compiler with 801different checking options use <samp><span class="option">--enable-stage1-checking</span></samp>. 802The list of checking options is the same as for <samp><span class="option">--enable-checking</span></samp>. 803If your system is too slow or too small to bootstrap a released compiler 804with checking for stage1 enabled, you can use ‘<samp><span class="samp">--disable-stage1-checking</span></samp>’ 805to disable checking for the stage1 compiler. 806 807 <br><dt><code>--enable-coverage</code><dt><code>--enable-coverage=</code><var>level</var><dd>With this option, the compiler is built to collect self coverage 808information, every time it is run. This is for internal development 809purposes, and only works when the compiler is being built with gcc. The 810<var>level</var> argument controls whether the compiler is built optimized or 811not, values are ‘<samp><span class="samp">opt</span></samp>’ and ‘<samp><span class="samp">noopt</span></samp>’. For coverage analysis you 812want to disable optimization, for performance analysis you want to 813enable optimization. When coverage is enabled, the default level is 814without optimization. 815 816 <br><dt><code>--enable-gather-detailed-mem-stats</code><dd>When this option is specified more detailed information on memory 817allocation is gathered. This information is printed when using 818<samp><span class="option">-fmem-report</span></samp>. 819 820 <br><dt><code>--enable-nls</code><dt><code>--disable-nls</code><dd>The <samp><span class="option">--enable-nls</span></samp> option enables Native Language Support (NLS), 821which lets GCC output diagnostics in languages other than American 822English. Native Language Support is enabled by default if not doing a 823canadian cross build. The <samp><span class="option">--disable-nls</span></samp> option disables NLS. 824 825 <br><dt><code>--with-included-gettext</code><dd>If NLS is enabled, the <samp><span class="option">--with-included-gettext</span></samp> option causes the build 826procedure to prefer its copy of GNU <samp><span class="command">gettext</span></samp>. 827 828 <br><dt><code>--with-catgets</code><dd>If NLS is enabled, and if the host lacks <code>gettext</code> but has the 829inferior <code>catgets</code> interface, the GCC build procedure normally 830ignores <code>catgets</code> and instead uses GCC's copy of the GNU 831<code>gettext</code> library. The <samp><span class="option">--with-catgets</span></samp> option causes the 832build procedure to use the host's <code>catgets</code> in this situation. 833 834 <br><dt><code>--with-libiconv-prefix=</code><var>dir</var><dd>Search for libiconv header files in <samp><var>dir</var><span class="file">/include</span></samp> and 835libiconv library files in <samp><var>dir</var><span class="file">/lib</span></samp>. 836 837 <br><dt><code>--enable-obsolete</code><dd>Enable configuration for an obsoleted system. If you attempt to 838configure GCC for a system (build, host, or target) which has been 839obsoleted, and you do not specify this flag, configure will halt with an 840error message. 841 842 <p>All support for systems which have been obsoleted in one release of GCC 843is removed entirely in the next major release, unless someone steps 844forward to maintain the port. 845 846 <br><dt><code>--enable-decimal-float</code><dt><code>--enable-decimal-float=yes</code><dt><code>--enable-decimal-float=no</code><dt><code>--enable-decimal-float=bid</code><dt><code>--enable-decimal-float=dpd</code><dt><code>--disable-decimal-float</code><dd>Enable (or disable) support for the C decimal floating point extension 847that is in the IEEE 754-2008 standard. This is enabled by default only 848on PowerPC, i386, and x86_64 GNU/Linux systems. Other systems may also 849support it, but require the user to specifically enable it. You can 850optionally control which decimal floating point format is used (either 851‘<samp><span class="samp">bid</span></samp>’ or ‘<samp><span class="samp">dpd</span></samp>’). The ‘<samp><span class="samp">bid</span></samp>’ (binary integer decimal) 852format is default on i386 and x86_64 systems, and the ‘<samp><span class="samp">dpd</span></samp>’ 853(densely packed decimal) format is default on PowerPC systems. 854 855 <br><dt><code>--enable-fixed-point</code><dt><code>--disable-fixed-point</code><dd>Enable (or disable) support for C fixed-point arithmetic. 856This option is enabled by default for some targets (such as MIPS) which 857have hardware-support for fixed-point operations. On other targets, you 858may enable this option manually. 859 860 <br><dt><code>--with-long-double-128</code><dd>Specify if <code>long double</code> type should be 128-bit by default on selected 861GNU/Linux architectures. If using <code>--without-long-double-128</code>, 862<code>long double</code> will be by default 64-bit, the same as <code>double</code> type. 863When neither of these configure options are used, the default will be 864128-bit <code>long double</code> when built against GNU C Library 2.4 and later, 86564-bit <code>long double</code> otherwise. 866 867 <br><dt><code>--with-gmp=</code><var>pathname</var><dt><code>--with-gmp-include=</code><var>pathname</var><dt><code>--with-gmp-lib=</code><var>pathname</var><dt><code>--with-mpfr=</code><var>pathname</var><dt><code>--with-mpfr-include=</code><var>pathname</var><dt><code>--with-mpfr-lib=</code><var>pathname</var><dt><code>--with-mpc=</code><var>pathname</var><dt><code>--with-mpc-include=</code><var>pathname</var><dt><code>--with-mpc-lib=</code><var>pathname</var><dd>If you want to build GCC but do not have the GMP library, the MPFR 868library and/or the MPC library installed in a standard location and 869do not have their sources present in the GCC source tree then you 870can explicitly specify the directory where they are installed 871(‘<samp><span class="samp">--with-gmp=</span><var>gmpinstalldir</var></samp>’, 872‘<samp><span class="samp">--with-mpfr=</span><var>mpfrinstalldir</var></samp>’, 873‘<samp><span class="samp">--with-mpc=</span><var>mpcinstalldir</var></samp>’). The 874<samp><span class="option">--with-gmp=</span><var>gmpinstalldir</var></samp> option is shorthand for 875<samp><span class="option">--with-gmp-lib=</span><var>gmpinstalldir</var><span class="option">/lib</span></samp> and 876<samp><span class="option">--with-gmp-include=</span><var>gmpinstalldir</var><span class="option">/include</span></samp>. Likewise the 877<samp><span class="option">--with-mpfr=</span><var>mpfrinstalldir</var></samp> option is shorthand for 878<samp><span class="option">--with-mpfr-lib=</span><var>mpfrinstalldir</var><span class="option">/lib</span></samp> and 879<samp><span class="option">--with-mpfr-include=</span><var>mpfrinstalldir</var><span class="option">/include</span></samp>, also the 880<samp><span class="option">--with-mpc=</span><var>mpcinstalldir</var></samp> option is shorthand for 881<samp><span class="option">--with-mpc-lib=</span><var>mpcinstalldir</var><span class="option">/lib</span></samp> and 882<samp><span class="option">--with-mpc-include=</span><var>mpcinstalldir</var><span class="option">/include</span></samp>. If these 883shorthand assumptions are not correct, you can use the explicit 884include and lib options directly. You might also need to ensure the 885shared libraries can be found by the dynamic linker when building and 886using GCC, for example by setting the runtime shared library path 887variable (<samp><span class="env">LD_LIBRARY_PATH</span></samp> on GNU/Linux and Solaris systems). 888 889 <p>These flags are applicable to the host platform only. When building 890a cross compiler, they will not be used to configure target libraries. 891 892 <br><dt><code>--with-isl=</code><var>pathname</var><dt><code>--with-isl-include=</code><var>pathname</var><dt><code>--with-isl-lib=</code><var>pathname</var><dt><code>--with-cloog=</code><var>pathname</var><dt><code>--with-cloog-include=</code><var>pathname</var><dt><code>--with-cloog-lib=</code><var>pathname</var><dd>If you do not have ISL and the CLooG 893libraries installed in a standard location and you want to build GCC, 894you can explicitly specify the directory where they are installed 895(‘<samp><span class="samp">--with-isl=</span><var>islinstalldir</var></samp>’, 896‘<samp><span class="samp">--with-cloog=</span><var>clooginstalldir</var></samp>’). The 897<samp><span class="option">--with-isl=</span><var>islinstalldir</var></samp> option is shorthand for 898<samp><span class="option">--with-isl-lib=</span><var>islinstalldir</var><span class="option">/lib</span></samp> and 899<samp><span class="option">--with-isl-include=</span><var>islinstalldir</var><span class="option">/include</span></samp>. Likewise the 900<samp><span class="option">--with-cloog=</span><var>clooginstalldir</var></samp> option is shorthand for 901<samp><span class="option">--with-cloog-lib=</span><var>clooginstalldir</var><span class="option">/lib</span></samp> and 902<samp><span class="option">--with-cloog-include=</span><var>clooginstalldir</var><span class="option">/include</span></samp>. If these 903shorthand assumptions are not correct, you can use the explicit 904include and lib options directly. 905 906 <p>These flags are applicable to the host platform only. When building 907a cross compiler, they will not be used to configure target libraries. 908 909 <br><dt><code>--with-host-libstdcxx=</code><var>linker-args</var><dd>If you are linking with a static copy of PPL, you can use this option 910to specify how the linker should find the standard C++ library used 911internally by PPL. Typical values of <var>linker-args</var> might be 912‘<samp><span class="samp">-lstdc++</span></samp>’ or ‘<samp><span class="samp">-Wl,-Bstatic,-lstdc++,-Bdynamic -lm</span></samp>’. If you are 913linking with a shared copy of PPL, you probably do not need this 914option; shared library dependencies will cause the linker to search 915for the standard C++ library automatically. 916 917 <br><dt><code>--with-stage1-ldflags=</code><var>flags</var><dd>This option may be used to set linker flags to be used when linking 918stage 1 of GCC. These are also used when linking GCC if configured with 919<samp><span class="option">--disable-bootstrap</span></samp>. By default no special flags are used. 920 921 <br><dt><code>--with-stage1-libs=</code><var>libs</var><dd>This option may be used to set libraries to be used when linking stage 1 922of GCC. These are also used when linking GCC if configured with 923<samp><span class="option">--disable-bootstrap</span></samp>. The default is the argument to 924<samp><span class="option">--with-host-libstdcxx</span></samp>, if specified. 925 926 <br><dt><code>--with-boot-ldflags=</code><var>flags</var><dd>This option may be used to set linker flags to be used when linking 927stage 2 and later when bootstrapping GCC. If neither –with-boot-libs 928nor –with-host-libstdcxx is set to a value, then the default is 929‘<samp><span class="samp">-static-libstdc++ -static-libgcc</span></samp>’. 930 931 <br><dt><code>--with-boot-libs=</code><var>libs</var><dd>This option may be used to set libraries to be used when linking stage 2 932and later when bootstrapping GCC. The default is the argument to 933<samp><span class="option">--with-host-libstdcxx</span></samp>, if specified. 934 935 <br><dt><code>--with-debug-prefix-map=</code><var>map</var><dd>Convert source directory names using <samp><span class="option">-fdebug-prefix-map</span></samp> when 936building runtime libraries. ‘<samp><var>map</var></samp>’ is a space-separated 937list of maps of the form ‘<samp><var>old</var><span class="samp">=</span><var>new</var></samp>’. 938 939 <br><dt><code>--enable-linker-build-id</code><dd>Tells GCC to pass <samp><span class="option">--build-id</span></samp> option to the linker for all final 940links (links performed without the <samp><span class="option">-r</span></samp> or <samp><span class="option">--relocatable</span></samp> 941option), if the linker supports it. If you specify 942<samp><span class="option">--enable-linker-build-id</span></samp>, but your linker does not 943support <samp><span class="option">--build-id</span></samp> option, a warning is issued and the 944<samp><span class="option">--enable-linker-build-id</span></samp> option is ignored. The default is off. 945 946 <br><dt><code>--with-linker-hash-style=</code><var>choice</var><dd>Tells GCC to pass <samp><span class="option">--hash-style=</span><var>choice</var></samp> option to the 947linker for all final links. <var>choice</var> can be one of 948‘<samp><span class="samp">sysv</span></samp>’, ‘<samp><span class="samp">gnu</span></samp>’, and ‘<samp><span class="samp">both</span></samp>’ where ‘<samp><span class="samp">sysv</span></samp>’ is the default. 949 950 <br><dt><code>--enable-gnu-unique-object</code><dt><code>--disable-gnu-unique-object</code><dd>Tells GCC to use the gnu_unique_object relocation for C++ template 951static data members and inline function local statics. Enabled by 952default for a native toolchain with an assembler that accepts it and 953GLIBC 2.11 or above, otherwise disabled. 954 955 <br><dt><code>--enable-lto</code><dt><code>--disable-lto</code><dd>Enable support for link-time optimization (LTO). This is enabled by 956default, and may be disabled using <samp><span class="option">--disable-lto</span></samp>. 957 958 <br><dt><code>--with-plugin-ld=</code><var>pathname</var><dd>Enable an alternate linker to be used at link-time optimization (LTO) 959link time when <samp><span class="option">-fuse-linker-plugin</span></samp> is enabled. 960This linker should have plugin support such as gold starting with 961version 2.20 or GNU ld starting with version 2.21. 962See <samp><span class="option">-fuse-linker-plugin</span></samp> for details. 963 964 <br><dt><code>--enable-canonical-system-headers</code><dt><code>--disable-canonical-system-headers</code><dd>Enable system header path canonicalization for <samp><span class="file">libcpp</span></samp>. This can 965produce shorter header file paths in diagnostics and dependency output 966files, but these changed header paths may conflict with some compilation 967environments. Enabled by default, and may be disabled using 968<samp><span class="option">--disable-canonical-system-headers</span></samp>. 969</dl> 970 971<h4 class="subheading"><a name="TOC3"></a>Cross-Compiler-Specific Options</h4> 972 973<p>The following options only apply to building cross compilers. 974 975 <dl> 976<dt><code>--with-sysroot</code><dt><code>--with-sysroot=</code><var>dir</var><dd>Tells GCC to consider <var>dir</var> as the root of a tree that contains 977(a subset of) the root filesystem of the target operating system. 978Target system headers, libraries and run-time object files will be 979searched for in there. More specifically, this acts as if 980<samp><span class="option">--sysroot=</span><var>dir</var></samp> was added to the default options of the built 981compiler. The specified directory is not copied into the 982install tree, unlike the options <samp><span class="option">--with-headers</span></samp> and 983<samp><span class="option">--with-libs</span></samp> that this option obsoletes. The default value, 984in case <samp><span class="option">--with-sysroot</span></samp> is not given an argument, is 985<samp><span class="option">${gcc_tooldir}/sys-root</span></samp>. If the specified directory is a 986subdirectory of <samp><span class="option">${exec_prefix}</span></samp>, then it will be found relative to 987the GCC binaries if the installation tree is moved. 988 989 <p>This option affects the system root for the compiler used to build 990target libraries (which runs on the build system) and the compiler newly 991installed with <code>make install</code>; it does not affect the compiler which is 992used to build GCC itself. 993 994 <p>If you specify the <samp><span class="option">--with-native-system-header-dir=</span><var>dirname</var></samp> 995option then the compiler will search that directory within <var>dirname</var> for 996native system headers rather than the default <samp><span class="file">/usr/include</span></samp>. 997 998 <br><dt><code>--with-build-sysroot</code><dt><code>--with-build-sysroot=</code><var>dir</var><dd>Tells GCC to consider <var>dir</var> as the system root (see 999<samp><span class="option">--with-sysroot</span></samp>) while building target libraries, instead of 1000the directory specified with <samp><span class="option">--with-sysroot</span></samp>. This option is 1001only useful when you are already using <samp><span class="option">--with-sysroot</span></samp>. You 1002can use <samp><span class="option">--with-build-sysroot</span></samp> when you are configuring with 1003<samp><span class="option">--prefix</span></samp> set to a directory that is different from the one in 1004which you are installing GCC and your target libraries. 1005 1006 <p>This option affects the system root for the compiler used to build 1007target libraries (which runs on the build system); it does not affect 1008the compiler which is used to build GCC itself. 1009 1010 <p>If you specify the <samp><span class="option">--with-native-system-header-dir=</span><var>dirname</var></samp> 1011option then the compiler will search that directory within <var>dirname</var> for 1012native system headers rather than the default <samp><span class="file">/usr/include</span></samp>. 1013 1014 <br><dt><code>--with-headers</code><dt><code>--with-headers=</code><var>dir</var><dd>Deprecated in favor of <samp><span class="option">--with-sysroot</span></samp>. 1015Specifies that target headers are available when building a cross compiler. 1016The <var>dir</var> argument specifies a directory which has the target include 1017files. These include files will be copied into the <samp><span class="file">gcc</span></samp> install 1018directory. <em>This option with the </em><var>dir</var><em> argument is required</em> when 1019building a cross compiler, if <samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/sys-include</span></samp> 1020doesn't pre-exist. If <samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/sys-include</span></samp> does 1021pre-exist, the <var>dir</var> argument may be omitted. <samp><span class="command">fixincludes</span></samp> 1022will be run on these files to make them compatible with GCC. 1023 1024 <br><dt><code>--without-headers</code><dd>Tells GCC not use any target headers from a libc when building a cross 1025compiler. When crossing to GNU/Linux, you need the headers so GCC 1026can build the exception handling for libgcc. 1027 1028 <br><dt><code>--with-libs</code><dt><code>--with-libs="</code><var>dir1</var> <var>dir2</var><code> ... </code><var>dirN</var><code>"</code><dd>Deprecated in favor of <samp><span class="option">--with-sysroot</span></samp>. 1029Specifies a list of directories which contain the target runtime 1030libraries. These libraries will be copied into the <samp><span class="file">gcc</span></samp> install 1031directory. If the directory list is omitted, this option has no 1032effect. 1033 1034 <br><dt><code>--with-newlib</code><dd>Specifies that ‘<samp><span class="samp">newlib</span></samp>’ is 1035being used as the target C library. This causes <code>__eprintf</code> to be 1036omitted from <samp><span class="file">libgcc.a</span></samp> on the assumption that it will be provided by 1037‘<samp><span class="samp">newlib</span></samp>’. 1038 1039 <br><dt><code>--with-avrlibc</code><dd>Specifies that ‘<samp><span class="samp">AVR-Libc</span></samp>’ is 1040being used as the target C library. This causes float support 1041functions like <code>__addsf3</code> to be omitted from <samp><span class="file">libgcc.a</span></samp> on 1042the assumption that it will be provided by <samp><span class="file">libm.a</span></samp>. For more 1043technical details, cf. <a href="http://gcc.gnu.org/PR54461">PR54461</a>. 1044This option is only supported for the AVR target. It is not supported for 1045RTEMS configurations, which currently use newlib. The option is 1046supported since version 4.7.2 and is the default in 4.8.0 and newer. 1047 1048 <br><dt><code>--with-build-time-tools=</code><var>dir</var><dd>Specifies where to find the set of target tools (assembler, linker, etc.) 1049that will be used while building GCC itself. This option can be useful 1050if the directory layouts are different between the system you are building 1051GCC on, and the system where you will deploy it. 1052 1053 <p>For example, on an ‘<samp><span class="samp">ia64-hp-hpux</span></samp>’ system, you may have the GNU 1054assembler and linker in <samp><span class="file">/usr/bin</span></samp>, and the native tools in a 1055different path, and build a toolchain that expects to find the 1056native tools in <samp><span class="file">/usr/bin</span></samp>. 1057 1058 <p>When you use this option, you should ensure that <var>dir</var> includes 1059<samp><span class="command">ar</span></samp>, <samp><span class="command">as</span></samp>, <samp><span class="command">ld</span></samp>, <samp><span class="command">nm</span></samp>, 1060<samp><span class="command">ranlib</span></samp> and <samp><span class="command">strip</span></samp> if necessary, and possibly 1061<samp><span class="command">objdump</span></samp>. Otherwise, GCC may use an inconsistent set of 1062tools. 1063</dl> 1064 1065<h4 class="subheading"><a name="TOC4"></a>Java-Specific Options</h4> 1066 1067<p>The following option applies to the build of the Java front end. 1068 1069 <dl> 1070<dt><code>--disable-libgcj</code><dd>Specify that the run-time libraries 1071used by GCJ should not be built. This is useful in case you intend 1072to use GCJ with some other run-time, or you're going to install it 1073separately, or it just happens not to build on your particular 1074machine. In general, if the Java front end is enabled, the GCJ 1075libraries will be enabled too, unless they're known to not work on 1076the target platform. If GCJ is enabled but ‘<samp><span class="samp">libgcj</span></samp>’ isn't built, you 1077may need to port it; in this case, before modifying the top-level 1078<samp><span class="file">configure.in</span></samp> so that ‘<samp><span class="samp">libgcj</span></samp>’ is enabled by default on this platform, 1079you may use <samp><span class="option">--enable-libgcj</span></samp> to override the default. 1080 1081 </dl> 1082 1083 <p>The following options apply to building ‘<samp><span class="samp">libgcj</span></samp>’. 1084 1085<h5 class="subsubheading"><a name="TOC5"></a>General Options</h5> 1086 1087 <dl> 1088<dt><code>--enable-java-maintainer-mode</code><dd>By default the ‘<samp><span class="samp">libjava</span></samp>’ build will not attempt to compile the 1089<samp><span class="file">.java</span></samp> source files to <samp><span class="file">.class</span></samp>. Instead, it will use the 1090<samp><span class="file">.class</span></samp> files from the source tree. If you use this option you 1091must have executables named <samp><span class="command">ecj1</span></samp> and <samp><span class="command">gjavah</span></samp> in your path 1092for use by the build. You must use this option if you intend to 1093modify any <samp><span class="file">.java</span></samp> files in <samp><span class="file">libjava</span></samp>. 1094 1095 <br><dt><code>--with-java-home=</code><var>dirname</var><dd>This ‘<samp><span class="samp">libjava</span></samp>’ option overrides the default value of the 1096‘<samp><span class="samp">java.home</span></samp>’ system property. It is also used to set 1097‘<samp><span class="samp">sun.boot.class.path</span></samp>’ to <samp><var>dirname</var><span class="file">/lib/rt.jar</span></samp>. By 1098default ‘<samp><span class="samp">java.home</span></samp>’ is set to <samp><var>prefix</var></samp> and 1099‘<samp><span class="samp">sun.boot.class.path</span></samp>’ to 1100<samp><var>datadir</var><span class="file">/java/libgcj-</span><var>version</var><span class="file">.jar</span></samp>. 1101 1102 <br><dt><code>--with-ecj-jar=</code><var>filename</var><dd>This option can be used to specify the location of an external jar 1103file containing the Eclipse Java compiler. A specially modified 1104version of this compiler is used by <samp><span class="command">gcj</span></samp> to parse 1105<samp><span class="file">.java</span></samp> source files. If this option is given, the 1106‘<samp><span class="samp">libjava</span></samp>’ build will create and install an <samp><span class="file">ecj1</span></samp> executable 1107which uses this jar file at runtime. 1108 1109 <p>If this option is not given, but an <samp><span class="file">ecj.jar</span></samp> file is found in 1110the topmost source tree at configure time, then the ‘<samp><span class="samp">libgcj</span></samp>’ 1111build will create and install <samp><span class="file">ecj1</span></samp>, and will also install the 1112discovered <samp><span class="file">ecj.jar</span></samp> into a suitable place in the install tree. 1113 1114 <p>If <samp><span class="file">ecj1</span></samp> is not installed, then the user will have to supply one 1115on his path in order for <samp><span class="command">gcj</span></samp> to properly parse <samp><span class="file">.java</span></samp> 1116source files. A suitable jar is available from 1117<a href="ftp://sourceware.org/pub/java/">ftp://sourceware.org/pub/java/</a>. 1118 1119 <br><dt><code>--disable-getenv-properties</code><dd>Don't set system properties from <samp><span class="env">GCJ_PROPERTIES</span></samp>. 1120 1121 <br><dt><code>--enable-hash-synchronization</code><dd>Use a global hash table for monitor locks. Ordinarily, 1122‘<samp><span class="samp">libgcj</span></samp>’'s ‘<samp><span class="samp">configure</span></samp>’ script automatically makes 1123the correct choice for this option for your platform. Only use 1124this if you know you need the library to be configured differently. 1125 1126 <br><dt><code>--enable-interpreter</code><dd>Enable the Java interpreter. The interpreter is automatically 1127enabled by default on all platforms that support it. This option 1128is really only useful if you want to disable the interpreter 1129(using <samp><span class="option">--disable-interpreter</span></samp>). 1130 1131 <br><dt><code>--disable-java-net</code><dd>Disable java.net. This disables the native part of java.net only, 1132using non-functional stubs for native method implementations. 1133 1134 <br><dt><code>--disable-jvmpi</code><dd>Disable JVMPI support. 1135 1136 <br><dt><code>--disable-libgcj-bc</code><dd>Disable BC ABI compilation of certain parts of libgcj. By default, 1137some portions of libgcj are compiled with <samp><span class="option">-findirect-dispatch</span></samp> 1138and <samp><span class="option">-fno-indirect-classes</span></samp>, allowing them to be overridden at 1139run-time. 1140 1141 <p>If <samp><span class="option">--disable-libgcj-bc</span></samp> is specified, libgcj is built without 1142these options. This allows the compile-time linker to resolve 1143dependencies when statically linking to libgcj. However it makes it 1144impossible to override the affected portions of libgcj at run-time. 1145 1146 <br><dt><code>--enable-reduced-reflection</code><dd>Build most of libgcj with <samp><span class="option">-freduced-reflection</span></samp>. This reduces 1147the size of libgcj at the expense of not being able to do accurate 1148reflection on the classes it contains. This option is safe if you 1149know that code using libgcj will never use reflection on the standard 1150runtime classes in libgcj (including using serialization, RMI or CORBA). 1151 1152 <br><dt><code>--with-ecos</code><dd>Enable runtime eCos target support. 1153 1154 <br><dt><code>--without-libffi</code><dd>Don't use ‘<samp><span class="samp">libffi</span></samp>’. This will disable the interpreter and JNI 1155support as well, as these require ‘<samp><span class="samp">libffi</span></samp>’ to work. 1156 1157 <br><dt><code>--enable-libgcj-debug</code><dd>Enable runtime debugging code. 1158 1159 <br><dt><code>--enable-libgcj-multifile</code><dd>If specified, causes all <samp><span class="file">.java</span></samp> source files to be 1160compiled into <samp><span class="file">.class</span></samp> files in one invocation of 1161‘<samp><span class="samp">gcj</span></samp>’. This can speed up build time, but is more 1162resource-intensive. If this option is unspecified or 1163disabled, ‘<samp><span class="samp">gcj</span></samp>’ is invoked once for each <samp><span class="file">.java</span></samp> 1164file to compile into a <samp><span class="file">.class</span></samp> file. 1165 1166 <br><dt><code>--with-libiconv-prefix=DIR</code><dd>Search for libiconv in <samp><span class="file">DIR/include</span></samp> and <samp><span class="file">DIR/lib</span></samp>. 1167 1168 <br><dt><code>--enable-sjlj-exceptions</code><dd>Force use of the <code>setjmp</code>/<code>longjmp</code>-based scheme for exceptions. 1169‘<samp><span class="samp">configure</span></samp>’ ordinarily picks the correct value based on the platform. 1170Only use this option if you are sure you need a different setting. 1171 1172 <br><dt><code>--with-system-zlib</code><dd>Use installed ‘<samp><span class="samp">zlib</span></samp>’ rather than that included with GCC. 1173 1174 <br><dt><code>--with-win32-nlsapi=ansi, unicows or unicode</code><dd>Indicates how MinGW ‘<samp><span class="samp">libgcj</span></samp>’ translates between UNICODE 1175characters and the Win32 API. 1176 1177 <br><dt><code>--enable-java-home</code><dd>If enabled, this creates a JPackage compatible SDK environment during install. 1178Note that if –enable-java-home is used, –with-arch-directory=ARCH must also 1179be specified. 1180 1181 <br><dt><code>--with-arch-directory=ARCH</code><dd>Specifies the name to use for the <samp><span class="file">jre/lib/ARCH</span></samp> directory in the SDK 1182environment created when –enable-java-home is passed. Typical names for this 1183directory include i386, amd64, ia64, etc. 1184 1185 <br><dt><code>--with-os-directory=DIR</code><dd>Specifies the OS directory for the SDK include directory. This is set to auto 1186detect, and is typically 'linux'. 1187 1188 <br><dt><code>--with-origin-name=NAME</code><dd>Specifies the JPackage origin name. This defaults to the 'gcj' in 1189java-1.5.0-gcj. 1190 1191 <br><dt><code>--with-arch-suffix=SUFFIX</code><dd>Specifies the suffix for the sdk directory. Defaults to the empty string. 1192Examples include '.x86_64' in 'java-1.5.0-gcj-1.5.0.0.x86_64'. 1193 1194 <br><dt><code>--with-jvm-root-dir=DIR</code><dd>Specifies where to install the SDK. Default is $(prefix)/lib/jvm. 1195 1196 <br><dt><code>--with-jvm-jar-dir=DIR</code><dd>Specifies where to install jars. Default is $(prefix)/lib/jvm-exports. 1197 1198 <br><dt><code>--with-python-dir=DIR</code><dd>Specifies where to install the Python modules used for aot-compile. DIR should 1199not include the prefix used in installation. For example, if the Python modules 1200are to be installed in /usr/lib/python2.5/site-packages, then 1201–with-python-dir=/lib/python2.5/site-packages should be passed. If this is 1202not specified, then the Python modules are installed in $(prefix)/share/python. 1203 1204 <br><dt><code>--enable-aot-compile-rpm</code><dd>Adds aot-compile-rpm to the list of installed scripts. 1205 1206 <br><dt><code>--enable-browser-plugin</code><dd>Build the gcjwebplugin web browser plugin. 1207 1208 <br><dt><code>--enable-static-libjava</code><dd>Build static libraries in libjava. The default is to only build shared 1209libraries. 1210 1211 <dl> 1212<dt><code>ansi</code><dd>Use the single-byte <code>char</code> and the Win32 A functions natively, 1213translating to and from UNICODE when using these functions. If 1214unspecified, this is the default. 1215 1216 <br><dt><code>unicows</code><dd>Use the <code>WCHAR</code> and Win32 W functions natively. Adds 1217<code>-lunicows</code> to <samp><span class="file">libgcj.spec</span></samp> to link with ‘<samp><span class="samp">libunicows</span></samp>’. 1218<samp><span class="file">unicows.dll</span></samp> needs to be deployed on Microsoft Windows 9X machines 1219running built executables. <samp><span class="file">libunicows.a</span></samp>, an open-source 1220import library around Microsoft's <code>unicows.dll</code>, is obtained from 1221<a href="http://libunicows.sourceforge.net/">http://libunicows.sourceforge.net/</a>, which also gives details 1222on getting <samp><span class="file">unicows.dll</span></samp> from Microsoft. 1223 1224 <br><dt><code>unicode</code><dd>Use the <code>WCHAR</code> and Win32 W functions natively. Does <em>not</em> 1225add <code>-lunicows</code> to <samp><span class="file">libgcj.spec</span></samp>. The built executables will 1226only run on Microsoft Windows NT and above. 1227</dl> 1228 </dl> 1229 1230<h5 class="subsubheading"><a name="TOC6"></a>AWT-Specific Options</h5> 1231 1232 <dl> 1233<dt><code>--with-x</code><dd>Use the X Window System. 1234 1235 <br><dt><code>--enable-java-awt=PEER(S)</code><dd>Specifies the AWT peer library or libraries to build alongside 1236‘<samp><span class="samp">libgcj</span></samp>’. If this option is unspecified or disabled, AWT 1237will be non-functional. Current valid values are <samp><span class="option">gtk</span></samp> and 1238<samp><span class="option">xlib</span></samp>. Multiple libraries should be separated by a 1239comma (i.e. <samp><span class="option">--enable-java-awt=gtk,xlib</span></samp>). 1240 1241 <br><dt><code>--enable-gtk-cairo</code><dd>Build the cairo Graphics2D implementation on GTK. 1242 1243 <br><dt><code>--enable-java-gc=TYPE</code><dd>Choose garbage collector. Defaults to <samp><span class="option">boehm</span></samp> if unspecified. 1244 1245 <br><dt><code>--disable-gtktest</code><dd>Do not try to compile and run a test GTK+ program. 1246 1247 <br><dt><code>--disable-glibtest</code><dd>Do not try to compile and run a test GLIB program. 1248 1249 <br><dt><code>--with-libart-prefix=PFX</code><dd>Prefix where libart is installed (optional). 1250 1251 <br><dt><code>--with-libart-exec-prefix=PFX</code><dd>Exec prefix where libart is installed (optional). 1252 1253 <br><dt><code>--disable-libarttest</code><dd>Do not try to compile and run a test libart program. 1254 1255</dl> 1256 1257<h5 class="subsubheading"><a name="TOC7"></a>Overriding <samp><span class="command">configure</span></samp> test results</h5> 1258 1259<p>Sometimes, it might be necessary to override the result of some 1260<samp><span class="command">configure</span></samp> test, for example in order to ease porting to a new 1261system or work around a bug in a test. The toplevel <samp><span class="command">configure</span></samp> 1262script provides three variables for this: 1263 1264 <dl> 1265<dt><code>build_configargs</code><dd><a name="index-g_t_0040code_007bbuild_005fconfigargs_007d-3"></a>The contents of this variable is passed to all build <samp><span class="command">configure</span></samp> 1266scripts. 1267 1268 <br><dt><code>host_configargs</code><dd><a name="index-g_t_0040code_007bhost_005fconfigargs_007d-4"></a>The contents of this variable is passed to all host <samp><span class="command">configure</span></samp> 1269scripts. 1270 1271 <br><dt><code>target_configargs</code><dd><a name="index-g_t_0040code_007btarget_005fconfigargs_007d-5"></a>The contents of this variable is passed to all target <samp><span class="command">configure</span></samp> 1272scripts. 1273 1274 </dl> 1275 1276 <p>In order to avoid shell and <samp><span class="command">make</span></samp> quoting issues for complex 1277overrides, you can pass a setting for <samp><span class="env">CONFIG_SITE</span></samp> and set 1278variables in the site file. 1279 1280 <p><hr /> 1281<p><a href="./index.html">Return to the GCC Installation page</a> 1282 1283<!-- ***Building**************************************************************** --> 1284<!-- ***Testing***************************************************************** --> 1285<!-- ***Final install*********************************************************** --> 1286<!-- ***Binaries**************************************************************** --> 1287<!-- ***Specific**************************************************************** --> 1288<!-- ***Old documentation****************************************************** --> 1289<!-- ***GFDL******************************************************************** --> 1290<!-- *************************************************************************** --> 1291<!-- Part 6 The End of the Document --> 1292</body></html> 1293 1294