configure.html revision 1.1.1.13
1 1.1.1.13 mrg <html lang="en"> 2 1.1.1.13 mrg <head> 3 1.1.1.13 mrg <title>Installing GCC: Configuration</title> 4 1.1.1.13 mrg <meta http-equiv="Content-Type" content="text/html"> 5 1.1.1.13 mrg <meta name="description" content="Installing GCC: Configuration"> 6 1.1.1.13 mrg <meta name="generator" content="makeinfo 4.13"> 7 1.1.1.13 mrg <link title="Top" rel="top" href="#Top"> 8 1.1.1.13 mrg <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 9 1.1.1.13 mrg <!-- 10 1.1.1.13 mrg Copyright (C) 1988-2017 Free Software Foundation, Inc. 11 1.1 mrg 12 1.1.1.13 mrg Permission is granted to copy, distribute and/or modify this document 13 1.1.1.3 skrll under the terms of the GNU Free Documentation License, Version 1.3 or 14 1.1 mrg any later version published by the Free Software Foundation; with no 15 1.1 mrg Invariant Sections, the Front-Cover texts being (a) (see below), and 16 1.1 mrg with the Back-Cover Texts being (b) (see below). A copy of the 17 1.1.1.13 mrg license is included in the section entitled "GNU Free Documentation License". 18 1.1 mrg 19 1.1 mrg (a) The FSF's Front-Cover Text is: 20 1.1 mrg 21 1.1.1.13 mrg A GNU Manual 22 1.1 mrg 23 1.1 mrg (b) The FSF's Back-Cover Text is: 24 1.1 mrg 25 1.1.1.13 mrg You have freedom to copy and modify this GNU Manual, like GNU 26 1.1 mrg software. Copies published by the Free Software Foundation raise 27 1.1.1.13 mrg funds for GNU development.--> 28 1.1.1.13 mrg <meta http-equiv="Content-Style-Type" content="text/css"> 29 1.1.1.13 mrg <style type="text/css"><!-- 30 1.1.1.13 mrg pre.display { font-family:inherit } 31 1.1.1.13 mrg pre.format { font-family:inherit } 32 1.1.1.13 mrg pre.smalldisplay { font-family:inherit; font-size:smaller } 33 1.1.1.13 mrg pre.smallformat { font-family:inherit; font-size:smaller } 34 1.1.1.13 mrg pre.smallexample { font-size:smaller } 35 1.1.1.13 mrg pre.smalllisp { font-size:smaller } 36 1.1.1.13 mrg span.sc { font-variant:small-caps } 37 1.1.1.13 mrg span.roman { font-family:serif; font-weight:normal; } 38 1.1.1.13 mrg span.sansserif { font-family:sans-serif; font-weight:normal; } 39 1.1.1.13 mrg --></style> 40 1.1 mrg </head> 41 1.1.1.13 mrg <body> 42 1.1.1.13 mrg <h1 class="settitle">Installing GCC: Configuration</h1> 43 1.1.1.13 mrg <a name="index-Configuration-1"></a><a name="index-Installing-GCC_003a-Configuration-2"></a> 44 1.1.1.13 mrg Like most GNU software, GCC must be configured before it can be built. 45 1.1.1.11 mrg This document describes the recommended configuration procedure 46 1.1.1.11 mrg for both native and cross targets. 47 1.1.1.13 mrg 48 1.1.1.13 mrg <p>We use <var>srcdir</var> to refer to the toplevel source directory for 49 1.1.1.11 mrg GCC; we use <var>objdir</var> to refer to the toplevel build/object directory. 50 1.1.1.13 mrg 51 1.1.1.13 mrg <p>If you obtained the sources via SVN, <var>srcdir</var> must refer to the top 52 1.1.1.13 mrg <samp><span class="file">gcc</span></samp> directory, the one where the <samp><span class="file">MAINTAINERS</span></samp> file can be 53 1.1.1.13 mrg found, and not its <samp><span class="file">gcc</span></samp> subdirectory, otherwise the build will fail. 54 1.1.1.13 mrg 55 1.1.1.13 mrg <p>If either <var>srcdir</var> or <var>objdir</var> is located on an automounted NFS 56 1.1.1.13 mrg file system, the shell's built-in <samp><span class="command">pwd</span></samp> command will return 57 1.1 mrg temporary pathnames. Using these can lead to various sorts of build 58 1.1.1.13 mrg problems. To avoid this issue, set the <samp><span class="env">PWDCMD</span></samp> environment 59 1.1.1.13 mrg variable to an automounter-aware <samp><span class="command">pwd</span></samp> command, e.g., 60 1.1.1.13 mrg <samp><span class="command">pawd</span></samp> or ‘<samp><span class="samp">amq -w</span></samp>’, during the configuration and build 61 1.1 mrg phases. 62 1.1.1.13 mrg 63 1.1.1.13 mrg <p>First, we <strong>highly</strong> recommend that GCC be built into a 64 1.1 mrg separate directory from the sources which does <strong>not</strong> reside 65 1.1 mrg within the source tree. This is how we generally build GCC; building 66 1.1.1.13 mrg where <var>srcdir</var> == <var>objdir</var> should still work, but doesn't 67 1.1 mrg get extensive testing; building where <var>objdir</var> is a subdirectory 68 1.1 mrg of <var>srcdir</var> is unsupported. 69 1.1.1.13 mrg 70 1.1.1.13 mrg <p>If you have previously built GCC in the same directory for a 71 1.1.1.13 mrg different target machine, do ‘<samp><span class="samp">make distclean</span></samp>’ to delete all files 72 1.1.1.13 mrg that might be invalid. One of the files this deletes is <samp><span class="file">Makefile</span></samp>; 73 1.1.1.13 mrg if ‘<samp><span class="samp">make distclean</span></samp>’ complains that <samp><span class="file">Makefile</span></samp> does not exist 74 1.1.1.13 mrg or issues a message like “don't know how to make distclean” it probably 75 1.1 mrg means that the directory is already suitably clean. However, with the 76 1.1 mrg recommended method of building in a separate <var>objdir</var>, you should 77 1.1 mrg simply use a different <var>objdir</var> for each target. 78 1.1.1.13 mrg 79 1.1.1.13 mrg <p>Second, when configuring a native system, either <samp><span class="command">cc</span></samp> or 80 1.1.1.13 mrg <samp><span class="command">gcc</span></samp> must be in your path or you must set <samp><span class="env">CC</span></samp> in 81 1.1 mrg your environment before running configure. Otherwise the configuration 82 1.1 mrg scripts may fail. 83 1.1 mrg 84 1.1.1.13 mrg <p>To configure GCC: 85 1.1 mrg 86 1.1.1.13 mrg <pre class="smallexample"> % mkdir <var>objdir</var> 87 1.1.1.13 mrg % cd <var>objdir</var> 88 1.1.1.13 mrg % <var>srcdir</var>/configure [<var>options</var>] [<var>target</var>] 89 1.1.1.13 mrg </pre> 90 1.1.1.13 mrg <h3 class="heading"><a name="TOC0"></a>Distributor options</h3> 91 1.1 mrg 92 1.1 mrg <p>If you will be distributing binary versions of GCC, with modifications 93 1.1 mrg to the source code, you should use the options described in this 94 1.1 mrg section to make clear that your version contains modifications. 95 1.1.1.13 mrg 96 1.1.1.13 mrg <dl> 97 1.1.1.13 mrg <dt><code>--with-pkgversion=</code><var>version</var><dd>Specify a string that identifies your package. You may wish 98 1.1 mrg to include a build number or build date. This version string will be 99 1.1.1.13 mrg included in the output of <samp><span class="command">gcc --version</span></samp>. This suffix does 100 1.1.1.13 mrg not replace the default version string, only the ‘<samp><span class="samp">GCC</span></samp>’ part. 101 1.1.1.13 mrg 102 1.1.1.13 mrg <p>The default value is ‘<samp><span class="samp">GCC</span></samp>’. 103 1.1.1.13 mrg 104 1.1.1.13 mrg <br><dt><code>--with-bugurl=</code><var>url</var><dd>Specify the URL that users should visit if they wish to report a bug. 105 1.1 mrg You are of course welcome to forward bugs reported to you to the FSF, 106 1.1 mrg if you determine that they are not bugs in your modifications. 107 1.1 mrg 108 1.1.1.13 mrg <p>The default value refers to the FSF's GCC bug tracker. 109 1.1.1.13 mrg 110 1.1.1.13 mrg </dl> 111 1.1.1.13 mrg 112 1.1.1.13 mrg <h3 class="heading"><a name="TOC1"></a>Target specification</h3> 113 1.1.1.13 mrg 114 1.1.1.13 mrg <ul> 115 1.1.1.13 mrg <li>GCC has code to correctly determine the correct value for <var>target</var> 116 1.1 mrg for nearly all native systems. Therefore, we highly recommend you do 117 1.1 mrg not provide a configure target when configuring a native compiler. 118 1.1 mrg 119 1.1.1.13 mrg <li><var>target</var> must be specified as <samp><span class="option">--target=</span><var>target</var></samp> 120 1.1 mrg when configuring a cross compiler; examples of valid targets would be 121 1.1 mrg m68k-elf, sh-elf, etc. 122 1.1 mrg 123 1.1.1.13 mrg <li>Specifying just <var>target</var> instead of <samp><span class="option">--target=</span><var>target</var></samp> 124 1.1.1.13 mrg implies that the host defaults to <var>target</var>. 125 1.1.1.13 mrg </ul> 126 1.1.1.11 mrg 127 1.1.1.13 mrg <h3 class="heading"><a name="TOC2"></a>Options specification</h3> 128 1.1 mrg 129 1.1 mrg <p>Use <var>options</var> to override several configure time options for 130 1.1.1.13 mrg GCC. A list of supported <var>options</var> follows; ‘<samp><span class="samp">configure 131 1.1.1.13 mrg --help</span></samp>’ may list other options, but those not listed below may not 132 1.1 mrg work and should not normally be used. 133 1.1.1.13 mrg 134 1.1.1.13 mrg <p>Note that each <samp><span class="option">--enable</span></samp> option has a corresponding 135 1.1.1.13 mrg <samp><span class="option">--disable</span></samp> option and that each <samp><span class="option">--with</span></samp> option has a 136 1.1.1.13 mrg corresponding <samp><span class="option">--without</span></samp> option. 137 1.1.1.13 mrg 138 1.1.1.13 mrg <dl> 139 1.1.1.13 mrg <dt><code>--prefix=</code><var>dirname</var><dd>Specify the toplevel installation 140 1.1 mrg directory. This is the recommended way to install the tools into a directory 141 1.1 mrg other than the default. The toplevel installation directory defaults to 142 1.1.1.13 mrg <samp><span class="file">/usr/local</span></samp>. 143 1.1.1.13 mrg 144 1.1.1.13 mrg <p>We <strong>highly</strong> recommend against <var>dirname</var> being the same or a 145 1.1 mrg subdirectory of <var>objdir</var> or vice versa. If specifying a directory 146 1.1.1.13 mrg beneath a user's home directory tree, some shells will not expand 147 1.1.1.13 mrg <var>dirname</var> correctly if it contains the ‘<samp><span class="samp">~</span></samp>’ metacharacter; use 148 1.1.1.13 mrg <samp><span class="env">$HOME</span></samp> instead. 149 1.1.1.13 mrg 150 1.1.1.13 mrg <p>The following standard <samp><span class="command">autoconf</span></samp> options are supported. Normally you 151 1.1 mrg should not need to use these options. 152 1.1.1.13 mrg <dl> 153 1.1.1.13 mrg <dt><code>--exec-prefix=</code><var>dirname</var><dd>Specify the toplevel installation directory for architecture-dependent 154 1.1 mrg files. The default is <samp><var>prefix</var></samp>. 155 1.1.1.13 mrg 156 1.1.1.13 mrg <br><dt><code>--bindir=</code><var>dirname</var><dd>Specify the installation directory for the executables called by users 157 1.1.1.13 mrg (such as <samp><span class="command">gcc</span></samp> and <samp><span class="command">g++</span></samp>). The default is 158 1.1.1.13 mrg <samp><var>exec-prefix</var><span class="file">/bin</span></samp>. 159 1.1.1.13 mrg 160 1.1.1.13 mrg <br><dt><code>--libdir=</code><var>dirname</var><dd>Specify the installation directory for object code libraries and 161 1.1.1.13 mrg internal data files of GCC. The default is <samp><var>exec-prefix</var><span class="file">/lib</span></samp>. 162 1.1.1.13 mrg 163 1.1.1.13 mrg <br><dt><code>--libexecdir=</code><var>dirname</var><dd>Specify the installation directory for internal executables of GCC. 164 1.1.1.13 mrg The default is <samp><var>exec-prefix</var><span class="file">/libexec</span></samp>. 165 1.1.1.13 mrg 166 1.1.1.13 mrg <br><dt><code>--with-slibdir=</code><var>dirname</var><dd>Specify the installation directory for the shared libgcc library. The 167 1.1 mrg default is <samp><var>libdir</var></samp>. 168 1.1.1.13 mrg 169 1.1.1.13 mrg <br><dt><code>--datarootdir=</code><var>dirname</var><dd>Specify the root of the directory tree for read-only architecture-independent 170 1.1.1.13 mrg data files referenced by GCC. The default is <samp><var>prefix</var><span class="file">/share</span></samp>. 171 1.1.1.13 mrg 172 1.1.1.13 mrg <br><dt><code>--infodir=</code><var>dirname</var><dd>Specify the installation directory for documentation in info format. 173 1.1.1.13 mrg The default is <samp><var>datarootdir</var><span class="file">/info</span></samp>. 174 1.1.1.13 mrg 175 1.1.1.13 mrg <br><dt><code>--datadir=</code><var>dirname</var><dd>Specify the installation directory for some architecture-independent 176 1.1 mrg data files referenced by GCC. The default is <samp><var>datarootdir</var></samp>. 177 1.1.1.13 mrg 178 1.1.1.13 mrg <br><dt><code>--docdir=</code><var>dirname</var><dd>Specify the installation directory for documentation files (other 179 1.1.1.13 mrg than Info) for GCC. The default is <samp><var>datarootdir</var><span class="file">/doc</span></samp>. 180 1.1.1.13 mrg 181 1.1.1.13 mrg <br><dt><code>--htmldir=</code><var>dirname</var><dd>Specify the installation directory for HTML documentation files. 182 1.1 mrg The default is <samp><var>docdir</var></samp>. 183 1.1.1.13 mrg 184 1.1.1.13 mrg <br><dt><code>--pdfdir=</code><var>dirname</var><dd>Specify the installation directory for PDF documentation files. 185 1.1 mrg The default is <samp><var>docdir</var></samp>. 186 1.1.1.13 mrg 187 1.1.1.13 mrg <br><dt><code>--mandir=</code><var>dirname</var><dd>Specify the installation directory for manual pages. The default is 188 1.1.1.13 mrg <samp><var>datarootdir</var><span class="file">/man</span></samp>. (Note that the manual pages are only extracts 189 1.1 mrg from the full GCC manuals, which are provided in Texinfo format. The manpages 190 1.1 mrg are derived by an automatic conversion process from parts of the full 191 1.1 mrg manual.) 192 1.1.1.13 mrg 193 1.1.1.13 mrg <br><dt><code>--with-gxx-include-dir=</code><var>dirname</var><dd>Specify 194 1.1 mrg the installation directory for G++ header files. The default depends 195 1.1 mrg on other configuration options, and differs between cross and native 196 1.1 mrg configurations. 197 1.1.1.13 mrg 198 1.1.1.13 mrg <br><dt><code>--with-specs=</code><var>specs</var><dd>Specify additional command line driver SPECS. 199 1.1.1.3 skrll This can be useful if you need to turn on a non-standard feature by 200 1.1.1.13 mrg default without modifying the compiler's source code, for instance 201 1.1.1.13 mrg <samp><span class="option">--with-specs=%{!fcommon:%{!fno-common:-fno-common}}</span></samp>. 202 1.1.1.3 skrll See “Spec Files” in the main manual 203 1.1.1.3 skrll 204 1.1.1.13 mrg </dl> 205 1.1.1.13 mrg 206 1.1.1.13 mrg <br><dt><code>--program-prefix=</code><var>prefix</var><dd>GCC supports some transformations of the names of its programs when 207 1.1 mrg installing them. This option prepends <var>prefix</var> to the names of 208 1.1 mrg programs to install in <var>bindir</var> (see above). For example, specifying 209 1.1.1.13 mrg <samp><span class="option">--program-prefix=foo-</span></samp> would result in ‘<samp><span class="samp">gcc</span></samp>’ 210 1.1.1.13 mrg being installed as <samp><span class="file">/usr/local/bin/foo-gcc</span></samp>. 211 1.1.1.13 mrg 212 1.1.1.13 mrg <br><dt><code>--program-suffix=</code><var>suffix</var><dd>Appends <var>suffix</var> to the names of programs to install in <var>bindir</var> 213 1.1.1.13 mrg (see above). For example, specifying <samp><span class="option">--program-suffix=-3.1</span></samp> 214 1.1.1.13 mrg would result in ‘<samp><span class="samp">gcc</span></samp>’ being installed as 215 1.1.1.13 mrg <samp><span class="file">/usr/local/bin/gcc-3.1</span></samp>. 216 1.1.1.13 mrg 217 1.1.1.13 mrg <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 218 1.1 mrg of programs to install in <var>bindir</var> (see above). <var>pattern</var> has to 219 1.1.1.13 mrg consist of one or more basic ‘<samp><span class="samp">sed</span></samp>’ editing commands, separated by 220 1.1.1.13 mrg semicolons. For example, if you want the ‘<samp><span class="samp">gcc</span></samp>’ program name to be 221 1.1.1.13 mrg transformed to the installed program <samp><span class="file">/usr/local/bin/myowngcc</span></samp> and 222 1.1.1.13 mrg the ‘<samp><span class="samp">g++</span></samp>’ program name to be transformed to 223 1.1.1.13 mrg <samp><span class="file">/usr/local/bin/gspecial++</span></samp> without changing other program names, 224 1.1 mrg you could use the pattern 225 1.1.1.13 mrg <samp><span class="option">--program-transform-name='s/^gcc$/myowngcc/; s/^g++$/gspecial++/'</span></samp> 226 1.1 mrg to achieve this effect. 227 1.1.1.13 mrg 228 1.1.1.13 mrg <p>All three options can be combined and used together, resulting in more 229 1.1 mrg complex conversion patterns. As a basic rule, <var>prefix</var> (and 230 1.1 mrg <var>suffix</var>) are prepended (appended) before further transformations 231 1.1 mrg can happen with a special transformation script <var>pattern</var>. 232 1.1.1.13 mrg 233 1.1.1.13 mrg <p>As currently implemented, this option only takes effect for native 234 1.1.1.13 mrg builds; cross compiler binaries' names are not transformed even when a 235 1.1 mrg transformation is explicitly asked for by one of these options. 236 1.1.1.13 mrg 237 1.1.1.13 mrg <p>For native builds, some of the installed programs are also installed 238 1.1 mrg with the target alias in front of their name, as in 239 1.1.1.13 mrg ‘<samp><span class="samp">i686-pc-linux-gnu-gcc</span></samp>’. All of the above transformations happen 240 1.1 mrg before the target alias is prepended to the name—so, specifying 241 1.1.1.13 mrg <samp><span class="option">--program-prefix=foo-</span></samp> and <samp><span class="option">program-suffix=-3.1</span></samp>, the 242 1.1 mrg resulting binary would be installed as 243 1.1.1.13 mrg <samp><span class="file">/usr/local/bin/i686-pc-linux-gnu-foo-gcc-3.1</span></samp>. 244 1.1.1.13 mrg 245 1.1.1.13 mrg <p>As a last shortcoming, none of the installed Ada programs are 246 1.1 mrg transformed yet, which will be fixed in some time. 247 1.1.1.13 mrg 248 1.1.1.13 mrg <br><dt><code>--with-local-prefix=</code><var>dirname</var><dd>Specify the 249 1.1 mrg installation directory for local include files. The default is 250 1.1.1.13 mrg <samp><span class="file">/usr/local</span></samp>. Specify this option if you want the compiler to 251 1.1.1.13 mrg search directory <samp><var>dirname</var><span class="file">/include</span></samp> for locally installed 252 1.1.1.13 mrg header files <em>instead</em> of <samp><span class="file">/usr/local/include</span></samp>. 253 1.1.1.13 mrg 254 1.1.1.13 mrg <p>You should specify <samp><span class="option">--with-local-prefix</span></samp> <strong>only</strong> if your 255 1.1.1.13 mrg site has a different convention (not <samp><span class="file">/usr/local</span></samp>) for where to put 256 1.1 mrg site-specific files. 257 1.1.1.13 mrg 258 1.1.1.13 mrg <p>The default value for <samp><span class="option">--with-local-prefix</span></samp> is <samp><span class="file">/usr/local</span></samp> 259 1.1.1.13 mrg regardless of the value of <samp><span class="option">--prefix</span></samp>. Specifying 260 1.1.1.13 mrg <samp><span class="option">--prefix</span></samp> has no effect on which directory GCC searches for 261 1.1 mrg local header files. This may seem counterintuitive, but actually it is 262 1.1 mrg logical. 263 1.1.1.13 mrg 264 1.1.1.13 mrg <p>The purpose of <samp><span class="option">--prefix</span></samp> is to specify where to <em>install 265 1.1.1.13 mrg GCC</em>. The local header files in <samp><span class="file">/usr/local/include</span></samp>—if you put 266 1.1 mrg any in that directory—are not part of GCC. They are part of other 267 1.1 mrg programs—perhaps many others. (GCC installs its own header files in 268 1.1.1.13 mrg another directory which is based on the <samp><span class="option">--prefix</span></samp> value.) 269 1.1.1.13 mrg 270 1.1.1.13 mrg <p>Both the local-prefix include directory and the GCC-prefix include 271 1.1.1.13 mrg directory are part of GCC's “system include” directories. Although these 272 1.1 mrg two directories are not fixed, they need to be searched in the proper 273 1.1 mrg order for the correct processing of the include_next directive. The 274 1.1 mrg local-prefix include directory is searched before the GCC-prefix 275 1.1 mrg include directory. Another characteristic of system include directories 276 1.1 mrg is that pedantic warnings are turned off for headers in these directories. 277 1.1.1.13 mrg 278 1.1.1.13 mrg <p>Some autoconf macros add <samp><span class="option">-I </span><var>directory</var></samp> options to the 279 1.1 mrg compiler command line, to ensure that directories containing installed 280 1.1.1.13 mrg packages' headers are searched. When <var>directory</var> is one of GCC's 281 1.1 mrg system include directories, GCC will ignore the option so that system 282 1.1 mrg directories continue to be processed in the correct order. This 283 1.1 mrg may result in a search order different from what was specified but the 284 1.1 mrg directory will still be searched. 285 1.1.1.13 mrg 286 1.1.1.13 mrg <p>GCC automatically searches for ordinary libraries using 287 1.1.1.13 mrg <samp><span class="env">GCC_EXEC_PREFIX</span></samp>. Thus, when the same installation prefix is 288 1.1 mrg used for both GCC and packages, GCC will automatically search for 289 1.1 mrg both headers and libraries. This provides a configuration that is 290 1.1 mrg easy to use. GCC behaves in a manner similar to that when it is 291 1.1.1.13 mrg installed as a system compiler in <samp><span class="file">/usr</span></samp>. 292 1.1.1.13 mrg 293 1.1.1.13 mrg <p>Sites that need to install multiple versions of GCC may not want to 294 1.1 mrg use the above simple configuration. It is possible to use the 295 1.1.1.13 mrg <samp><span class="option">--program-prefix</span></samp>, <samp><span class="option">--program-suffix</span></samp> and 296 1.1.1.13 mrg <samp><span class="option">--program-transform-name</span></samp> options to install multiple versions 297 1.1 mrg into a single directory, but it may be simpler to use different prefixes 298 1.1.1.13 mrg and the <samp><span class="option">--with-local-prefix</span></samp> option to specify the location of the 299 1.1 mrg site-specific files for each version. It will then be necessary for 300 1.1 mrg users to specify explicitly the location of local site libraries 301 1.1.1.13 mrg (e.g., with <samp><span class="env">LIBRARY_PATH</span></samp>). 302 1.1.1.13 mrg 303 1.1.1.13 mrg <p>The same value can be used for both <samp><span class="option">--with-local-prefix</span></samp> and 304 1.1.1.13 mrg <samp><span class="option">--prefix</span></samp> provided it is not <samp><span class="file">/usr</span></samp>. This can be used 305 1.1.1.13 mrg to avoid the default search of <samp><span class="file">/usr/local/include</span></samp>. 306 1.1.1.13 mrg 307 1.1.1.13 mrg <p><strong>Do not</strong> specify <samp><span class="file">/usr</span></samp> as the <samp><span class="option">--with-local-prefix</span></samp>! 308 1.1.1.13 mrg The directory you use for <samp><span class="option">--with-local-prefix</span></samp> <strong>must not</strong> 309 1.1.1.13 mrg contain any of the system's standard header files. If it did contain 310 1.1 mrg them, certain programs would be miscompiled (including GNU Emacs, on 311 1.1 mrg certain targets), because this would override and nullify the header 312 1.1.1.13 mrg file corrections made by the <samp><span class="command">fixincludes</span></samp> script. 313 1.1.1.13 mrg 314 1.1.1.13 mrg <p>Indications are that people who use this option use it based on mistaken 315 1.1 mrg ideas of what it is for. People use it as if it specified where to 316 1.1 mrg install part of GCC. Perhaps they make this assumption because 317 1.1 mrg installing GCC creates the directory. 318 1.1.1.13 mrg 319 1.1.1.13 mrg <br><dt><code>--with-gcc-major-version-only</code><dd>Specifies that GCC should use only the major number rather than 320 1.1.1.10 mrg <var>major</var>.<var>minor</var>.<var>patchlevel</var> in filesystem paths. 321 1.1.1.13 mrg 322 1.1.1.13 mrg <br><dt><code>--with-native-system-header-dir=</code><var>dirname</var><dd>Specifies that <var>dirname</var> is the directory that contains native system 323 1.1.1.13 mrg header files, rather than <samp><span class="file">/usr/include</span></samp>. This option is most useful 324 1.1.1.3 skrll if you are creating a compiler that should be isolated from the system 325 1.1.1.3 skrll as much as possible. It is most commonly used with the 326 1.1.1.13 mrg <samp><span class="option">--with-sysroot</span></samp> option and will cause GCC to search 327 1.1.1.3 skrll <var>dirname</var> inside the system root specified by that option. 328 1.1.1.13 mrg 329 1.1.1.13 mrg <br><dt><code>--enable-shared[=</code><var>package</var><code>[,...]]</code><dd>Build shared versions of libraries, if shared libraries are supported on 330 1.1 mrg the target platform. Unlike GCC 2.95.x and earlier, shared libraries 331 1.1 mrg are enabled by default on all platforms that support shared libraries. 332 1.1.1.13 mrg 333 1.1.1.13 mrg <p>If a list of packages is given as an argument, build shared libraries 334 1.1 mrg only for the listed packages. For other packages, only static libraries 335 1.1 mrg will be built. Package names currently recognized in the GCC tree are 336 1.1.1.13 mrg ‘<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 337 1.1.1.13 mrg ‘<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>’, 338 1.1.1.13 mrg ‘<samp><span class="samp">ada</span></samp>’, ‘<samp><span class="samp">libada</span></samp>’, ‘<samp><span class="samp">libgo</span></samp>’, and ‘<samp><span class="samp">libobjc</span></samp>’. 339 1.1.1.13 mrg Note ‘<samp><span class="samp">libiberty</span></samp>’ does not support shared libraries at all. 340 1.1.1.13 mrg 341 1.1.1.13 mrg <p>Use <samp><span class="option">--disable-shared</span></samp> to build only static libraries. Note that 342 1.1.1.13 mrg <samp><span class="option">--disable-shared</span></samp> does not accept a list of package names as 343 1.1.1.13 mrg argument, only <samp><span class="option">--enable-shared</span></samp> does. 344 1.1.1.13 mrg 345 1.1.1.13 mrg <p>Contrast with <samp><span class="option">--enable-host-shared</span></samp>, which affects <em>host</em> 346 1.1.1.6 mrg code. 347 1.1.1.13 mrg 348 1.1.1.13 mrg <br><dt><code>--enable-host-shared</code><dd>Specify that the <em>host</em> code should be built into position-independent 349 1.1.1.6 mrg machine code (with -fPIC), allowing it to be used within shared libraries, 350 1.1.1.6 mrg but yielding a slightly slower compiler. 351 1.1.1.13 mrg 352 1.1.1.13 mrg <p>This option is required when building the libgccjit.so library. 353 1.1.1.13 mrg 354 1.1.1.13 mrg <p>Contrast with <samp><span class="option">--enable-shared</span></samp>, which affects <em>target</em> 355 1.1.1.6 mrg libraries. 356 1.1.1.13 mrg 357 1.1.1.13 mrg <br><dt><code><a name="with-gnu-as"></a>--with-gnu-as</code><dd>Specify that the compiler should assume that the 358 1.1 mrg assembler it finds is the GNU assembler. However, this does not modify 359 1.1 mrg the rules to find an assembler and will result in confusion if the 360 1.1 mrg assembler found is not actually the GNU assembler. (Confusion may also 361 1.1 mrg result if the compiler finds the GNU assembler but has not been 362 1.1.1.13 mrg configured with <samp><span class="option">--with-gnu-as</span></samp>.) If you have more than one 363 1.1 mrg assembler installed on your system, you may want to use this option in 364 1.1.1.13 mrg connection with <samp><span class="option">--with-as=</span><var>pathname</var></samp> or 365 1.1.1.13 mrg <samp><span class="option">--with-build-time-tools=</span><var>pathname</var></samp>. 366 1.1.1.13 mrg 367 1.1.1.13 mrg <p>The following systems are the only ones where it makes a difference 368 1.1 mrg whether you use the GNU assembler. On any other system, 369 1.1.1.13 mrg <samp><span class="option">--with-gnu-as</span></samp> has no effect. 370 1.1.1.13 mrg 371 1.1.1.13 mrg <ul> 372 1.1.1.13 mrg <li>‘<samp><span class="samp">hppa1.0-</span><var>any</var><span class="samp">-</span><var>any</var></samp>’ 373 1.1.1.13 mrg <li>‘<samp><span class="samp">hppa1.1-</span><var>any</var><span class="samp">-</span><var>any</var></samp>’ 374 1.1.1.13 mrg <li>‘<samp><span class="samp">sparc-sun-solaris2.</span><var>any</var></samp>’ 375 1.1.1.13 mrg <li>‘<samp><span class="samp">sparc64-</span><var>any</var><span class="samp">-solaris2.</span><var>any</var></samp>’ 376 1.1.1.13 mrg </ul> 377 1.1.1.13 mrg 378 1.1.1.13 mrg <br><dt><code><a name="with-as"></a>--with-as=</code><var>pathname</var><dd>Specify that the compiler should use the assembler pointed to by 379 1.1 mrg <var>pathname</var>, rather than the one found by the standard rules to find 380 1.1 mrg an assembler, which are: 381 1.1.1.13 mrg <ul> 382 1.1.1.13 mrg <li>Unless GCC is being built with a cross compiler, check the 383 1.1.1.13 mrg <samp><var>libexec</var><span class="file">/gcc/</span><var>target</var><span class="file">/</span><var>version</var></samp> directory. 384 1.1.1.13 mrg <var>libexec</var> defaults to <samp><var>exec-prefix</var><span class="file">/libexec</span></samp>; 385 1.1 mrg <var>exec-prefix</var> defaults to <var>prefix</var>, which 386 1.1.1.13 mrg defaults to <samp><span class="file">/usr/local</span></samp> unless overridden by the 387 1.1.1.13 mrg <samp><span class="option">--prefix=</span><var>pathname</var></samp> switch described above. <var>target</var> 388 1.1.1.13 mrg is the target system triple, such as ‘<samp><span class="samp">sparc-sun-solaris2.7</span></samp>’, and 389 1.1 mrg <var>version</var> denotes the GCC version, such as 3.0. 390 1.1 mrg 391 1.1.1.13 mrg <li>If the target system is the same that you are building on, check 392 1.1.1.13 mrg operating system specific directories (e.g. <samp><span class="file">/usr/ccs/bin</span></samp> on 393 1.1 mrg Sun Solaris 2). 394 1.1 mrg 395 1.1.1.13 mrg <li>Check in the <samp><span class="env">PATH</span></samp> for a tool whose name is prefixed by the 396 1.1 mrg target system triple. 397 1.1 mrg 398 1.1.1.13 mrg <li>Check in the <samp><span class="env">PATH</span></samp> for a tool whose name is not prefixed by the 399 1.1 mrg target system triple, if the host and target system triple are 400 1.1 mrg the same (in other words, we use a host tool if it can be used for 401 1.1.1.13 mrg the target as well). 402 1.1.1.13 mrg </ul> 403 1.1 mrg 404 1.1.1.13 mrg <p>You may want to use <samp><span class="option">--with-as</span></samp> if no assembler 405 1.1 mrg is installed in the directories listed above, or if you have multiple 406 1.1 mrg assemblers installed and want to choose one that is not found by the 407 1.1 mrg above rules. 408 1.1.1.13 mrg 409 1.1.1.13 mrg <br><dt><code><a name="with-gnu-ld"></a>--with-gnu-ld</code><dd>Same as <a href="#with-gnu-as"><samp><span class="option">--with-gnu-as</span></samp></a> 410 1.1 mrg but for the linker. 411 1.1.1.13 mrg 412 1.1.1.13 mrg <br><dt><code>--with-ld=</code><var>pathname</var><dd>Same as <a href="#with-as"><samp><span class="option">--with-as</span></samp></a> 413 1.1 mrg but for the linker. 414 1.1.1.13 mrg 415 1.1.1.13 mrg <br><dt><code>--with-stabs</code><dd>Specify that stabs debugging 416 1.1 mrg information should be used instead of whatever format the host normally 417 1.1 mrg uses. Normally GCC uses the same debug format as the host system. 418 1.1.1.13 mrg 419 1.1.1.13 mrg <p>On MIPS based systems and on Alphas, you must specify whether you want 420 1.1.1.13 mrg GCC to create the normal ECOFF debugging format, or to use BSD-style 421 1.1.1.13 mrg stabs passed through the ECOFF symbol table. The normal ECOFF debug 422 1.1.1.13 mrg format cannot fully handle languages other than C. BSD stabs format can 423 1.1.1.13 mrg handle other languages, but it only works with the GNU debugger GDB. 424 1.1.1.13 mrg 425 1.1.1.13 mrg <p>Normally, GCC uses the ECOFF debugging format by default; if you 426 1.1.1.13 mrg prefer BSD stabs, specify <samp><span class="option">--with-stabs</span></samp> when you configure GCC. 427 1.1.1.13 mrg 428 1.1.1.13 mrg <p>No matter which default you choose when you configure GCC, the user 429 1.1.1.13 mrg can use the <samp><span class="option">-gcoff</span></samp> and <samp><span class="option">-gstabs+</span></samp> options to specify explicitly 430 1.1.1.13 mrg the debug format for a particular compilation. 431 1.1.1.13 mrg 432 1.1.1.13 mrg <p><samp><span class="option">--with-stabs</span></samp> is meaningful on the ISC system on the 386, also, if 433 1.1.1.13 mrg <samp><span class="option">--with-gas</span></samp> is used. It selects use of stabs debugging 434 1.1.1.13 mrg information embedded in COFF output. This kind of debugging information 435 1.1.1.13 mrg supports C++ well; ordinary COFF debugging information does not. 436 1.1.1.13 mrg 437 1.1.1.13 mrg <p><samp><span class="option">--with-stabs</span></samp> is also meaningful on 386 systems running SVR4. It 438 1.1.1.13 mrg selects use of stabs debugging information embedded in ELF output. The 439 1.1.1.13 mrg C++ compiler currently (2.6.0) does not support the DWARF debugging 440 1.1.1.13 mrg information normally used on 386 SVR4 platforms; stabs provide a 441 1.1.1.13 mrg workable alternative. This requires gas and gdb, as the normal SVR4 442 1.1.1.13 mrg tools can not generate or interpret stabs. 443 1.1.1.13 mrg 444 1.1.1.13 mrg <br><dt><code>--with-tls=</code><var>dialect</var><dd>Specify the default TLS dialect, for systems were there is a choice. 445 1.1.1.3 skrll For ARM targets, possible values for <var>dialect</var> are <code>gnu</code> or 446 1.1.1.3 skrll <code>gnu2</code>, which select between the original GNU dialect and the GNU TLS 447 1.1.1.3 skrll descriptor-based dialect. 448 1.1.1.13 mrg 449 1.1.1.13 mrg <br><dt><code>--enable-multiarch</code><dd>Specify whether to enable or disable multiarch support. The default is 450 1.1.1.3 skrll to check for glibc start files in a multiarch location, and enable it 451 1.1.1.3 skrll if the files are found. The auto detection is enabled for native builds, 452 1.1.1.13 mrg and for cross builds configured with <samp><span class="option">--with-sysroot</span></samp>, and without 453 1.1.1.13 mrg <samp><span class="option">--with-native-system-header-dir</span></samp>. 454 1.1.1.3 skrll More documentation about multiarch can be found at 455 1.1.1.8 mrg <a href="https://wiki.debian.org/Multiarch">https://wiki.debian.org/Multiarch</a>. 456 1.1.1.13 mrg 457 1.1.1.13 mrg <br><dt><code>--enable-sjlj-exceptions</code><dd>Force use of the <code>setjmp</code>/<code>longjmp</code>-based scheme for exceptions. 458 1.1.1.13 mrg ‘<samp><span class="samp">configure</span></samp>’ ordinarily picks the correct value based on the platform. 459 1.1.1.7 mrg Only use this option if you are sure you need a different setting. 460 1.1.1.13 mrg 461 1.1.1.13 mrg <br><dt><code>--enable-vtable-verify</code><dd>Specify whether to enable or disable the vtable verification feature. 462 1.1.1.6 mrg Enabling this feature causes libstdc++ to be built with its virtual calls 463 1.1.1.6 mrg in verifiable mode. This means that, when linked with libvtv, every 464 1.1.1.6 mrg virtual call in libstdc++ will verify the vtable pointer through which the 465 1.1.1.6 mrg call will be made before actually making the call. If not linked with libvtv, 466 1.1.1.13 mrg the verifier will call stub functions (in libstdc++ itself) and do nothing. 467 1.1.1.6 mrg If vtable verification is disabled, then libstdc++ is not built with its 468 1.1.1.6 mrg virtual calls in verifiable mode at all. However the libvtv library will 469 1.1.1.13 mrg still be built (see <samp><span class="option">--disable-libvtv</span></samp> to turn off building libvtv). 470 1.1.1.13 mrg <samp><span class="option">--disable-vtable-verify</span></samp> is the default. 471 1.1.1.13 mrg 472 1.1.1.13 mrg <br><dt><code>--disable-multilib</code><dd>Specify that multiple target 473 1.1 mrg libraries to support different target variants, calling 474 1.1 mrg conventions, etc. should not be built. The default is to build a 475 1.1 mrg predefined set of them. 476 1.1.1.13 mrg 477 1.1.1.13 mrg <p>Some targets provide finer-grained control over which multilibs are built 478 1.1.1.13 mrg (e.g., <samp><span class="option">--disable-softfloat</span></samp>): 479 1.1.1.13 mrg <dl> 480 1.1.1.13 mrg <dt><code>arm-*-*</code><dd>fpu, 26bit, underscore, interwork, biendian, nofmult. 481 1.1.1.13 mrg 482 1.1.1.13 mrg <br><dt><code>m68*-*-*</code><dd>softfloat, m68881, m68000, m68020. 483 1.1.1.13 mrg 484 1.1.1.13 mrg <br><dt><code>mips*-*-*</code><dd>single-float, biendian, softfloat. 485 1.1.1.13 mrg 486 1.1.1.13 mrg <br><dt><code>powerpc*-*-*, rs6000*-*-*</code><dd>aix64, pthread, softfloat, powercpu, powerpccpu, powerpcos, biendian, 487 1.1 mrg sysv, aix. 488 1.1 mrg 489 1.1.1.13 mrg </dl> 490 1.1.1.13 mrg 491 1.1.1.13 mrg <br><dt><code>--with-multilib-list=</code><var>list</var><dt><code>--without-multilib-list</code><dd>Specify what multilibs to build. <var>list</var> is a comma separated list of 492 1.1.1.10 mrg values, possibly consisting of a single value. Currently only implemented 493 1.1.1.13 mrg for arm*-*-*, sh*-*-* and x86-64-*-linux*. The accepted values and meaning 494 1.1.1.13 mrg for each target is given below. 495 1.1.1.13 mrg 496 1.1.1.13 mrg <dl> 497 1.1.1.13 mrg <dt><code>arm*-*-*</code><dd><var>list</var> is one of<code>default</code>, <code>aprofile</code> or <code>rmprofile</code>. 498 1.1.1.13 mrg Specifying <code>default</code> is equivalent to omitting this option, ie. only the 499 1.1.1.13 mrg default runtime library will be enabled. Specifying <code>aprofile</code> or 500 1.1.1.13 mrg <code>rmprofile</code> builds multilibs for a combination of ISA, architecture, 501 1.1.1.13 mrg FPU available and floating-point ABI. 502 1.1.1.13 mrg 503 1.1.1.13 mrg <p>The table below gives the combination of ISAs, architectures, FPUs and 504 1.1.1.10 mrg floating-point ABIs for which multilibs are built for each accepted value. 505 1.1.1.13 mrg 506 1.1.1.13 mrg <p><table summary=""><tr align="left"><td valign="top" width="15%">Option </td><td valign="top" width="28%">aprofile </td><td valign="top" width="30%">rmprofile 507 1.1.1.13 mrg <br></td></tr><tr align="left"><td valign="top" width="15%">ISAs 508 1.1.1.13 mrg </td><td valign="top" width="28%"><code>-marm</code> and <code>-mthumb</code> 509 1.1.1.13 mrg </td><td valign="top" width="30%"><code>-mthumb</code> 510 1.1.1.13 mrg <br></td></tr><tr align="left"><td valign="top" width="15%">Architectures<br><br><br><br><br><br> 511 1.1.1.13 mrg </td><td valign="top" width="28%">default architecture<br> 512 1.1.1.10 mrg <code>-march=armv7-a</code><br> 513 1.1.1.10 mrg <code>-march=armv7ve</code><br> 514 1.1.1.13 mrg <code>-march=armv8-a</code><br><br><br> 515 1.1.1.13 mrg </td><td valign="top" width="30%">default architecture<br> 516 1.1.1.10 mrg <code>-march=armv6s-m</code><br> 517 1.1.1.10 mrg <code>-march=armv7-m</code><br> 518 1.1.1.10 mrg <code>-march=armv7e-m</code><br> 519 1.1.1.10 mrg <code>-march=armv8-m.base</code><br> 520 1.1.1.10 mrg <code>-march=armv8-m.main</code><br> 521 1.1.1.13 mrg <code>-march=armv7</code> 522 1.1.1.13 mrg <br></td></tr><tr align="left"><td valign="top" width="15%">FPUs<br><br><br><br><br> 523 1.1.1.13 mrg </td><td valign="top" width="28%">none<br> 524 1.1.1.10 mrg <code>-mfpu=vfpv3-d16</code><br> 525 1.1.1.10 mrg <code>-mfpu=neon</code><br> 526 1.1.1.10 mrg <code>-mfpu=vfpv4-d16</code><br> 527 1.1.1.10 mrg <code>-mfpu=neon-vfpv4</code><br> 528 1.1.1.13 mrg <code>-mfpu=neon-fp-armv8</code> 529 1.1.1.13 mrg </td><td valign="top" width="30%">none<br> 530 1.1.1.10 mrg <code>-mfpu=vfpv3-d16</code><br> 531 1.1.1.10 mrg <code>-mfpu=fpv4-sp-d16</code><br> 532 1.1.1.10 mrg <code>-mfpu=fpv5-sp-d16</code><br> 533 1.1.1.13 mrg <code>-mfpu=fpv5-d16</code><br> 534 1.1.1.13 mrg <br></td></tr><tr align="left"><td valign="top" width="15%">floating-point ABIs<br><br> 535 1.1.1.13 mrg </td><td valign="top" width="28%"><code>-mfloat-abi=soft</code><br> 536 1.1.1.10 mrg <code>-mfloat-abi=softfp</code><br> 537 1.1.1.13 mrg <code>-mfloat-abi=hard</code> 538 1.1.1.13 mrg </td><td valign="top" width="30%"><code>-mfloat-abi=soft</code><br> 539 1.1.1.10 mrg <code>-mfloat-abi=softfp</code><br> 540 1.1.1.13 mrg <code>-mfloat-abi=hard</code> 541 1.1.1.13 mrg <br></td></tr></table> 542 1.1.1.10 mrg 543 1.1.1.13 mrg <br><dt><code>sh*-*-*</code><dd><var>list</var> is a comma separated list of CPU names. These must be of the 544 1.1 mrg form <code>sh*</code> or <code>m*</code> (in which case they match the compiler option 545 1.1 mrg for that processor). The list should not contain any endian options - 546 1.1.1.13 mrg these are handled by <samp><span class="option">--with-endian</span></samp>. 547 1.1.1.13 mrg 548 1.1.1.13 mrg <p>If <var>list</var> is empty, then there will be no multilibs for extra 549 1.1 mrg processors. The multilib for the secondary endian remains enabled. 550 1.1.1.13 mrg 551 1.1.1.13 mrg <p>As a special case, if an entry in the list starts with a <code>!</code> 552 1.1.1.13 mrg (exclamation point), then it is added to the list of excluded multilibs. 553 1.1.1.13 mrg Entries of this sort should be compatible with ‘<samp><span class="samp">MULTILIB_EXCLUDES</span></samp>’ 554 1.1 mrg (once the leading <code>!</code> has been stripped). 555 1.1.1.13 mrg 556 1.1.1.13 mrg <p>If <samp><span class="option">--with-multilib-list</span></samp> is not given, then a default set of 557 1.1.1.13 mrg multilibs is selected based on the value of <samp><span class="option">--target</span></samp>. This is 558 1.1 mrg usually the complete set of libraries, but some targets imply a more 559 1.1 mrg specialized subset. 560 1.1.1.11 mrg 561 1.1.1.13 mrg <p>Example 1: to configure a compiler for SH4A only, but supporting both 562 1.1.1.13 mrg endians, with little endian being the default: 563 1.1.1.13 mrg <pre class="smallexample"> --with-cpu=sh4a --with-endian=little,big --with-multilib-list= 564 1.1.1.13 mrg </pre> 565 1.1.1.13 mrg <p>Example 2: to configure a compiler for both SH4A and SH4AL-DSP, but with 566 1.1 mrg only little endian SH4AL: 567 1.1.1.13 mrg <pre class="smallexample"> --with-cpu=sh4a --with-endian=little,big \ 568 1.1.1.13 mrg --with-multilib-list=sh4al,!mb/m4al 569 1.1.1.13 mrg </pre> 570 1.1.1.13 mrg <br><dt><code>x86-64-*-linux*</code><dd><var>list</var> is a comma separated list of <code>m32</code>, <code>m64</code> and 571 1.1.1.3 skrll <code>mx32</code> to enable 32-bit, 64-bit and x32 run-time libraries, 572 1.1.1.3 skrll respectively. If <var>list</var> is empty, then there will be no multilibs 573 1.1.1.3 skrll and only the default run-time library will be enabled. 574 1.1.1.13 mrg 575 1.1.1.13 mrg <p>If <samp><span class="option">--with-multilib-list</span></samp> is not given, then only 32-bit and 576 1.1.1.13 mrg 64-bit run-time libraries will be enabled. 577 1.1.1.3 skrll </dl> 578 1.1.1.3 skrll 579 1.1.1.13 mrg <br><dt><code>--with-endian=</code><var>endians</var><dd>Specify what endians to use. 580 1.1 mrg Currently only implemented for sh*-*-*. 581 1.1.1.13 mrg 582 1.1.1.13 mrg <p><var>endians</var> may be one of the following: 583 1.1.1.13 mrg <dl> 584 1.1.1.13 mrg <dt><code>big</code><dd>Use big endian exclusively. 585 1.1.1.13 mrg <br><dt><code>little</code><dd>Use little endian exclusively. 586 1.1.1.13 mrg <br><dt><code>big,little</code><dd>Use big endian by default. Provide a multilib for little endian. 587 1.1.1.13 mrg <br><dt><code>little,big</code><dd>Use little endian by default. Provide a multilib for big endian. 588 1.1 mrg </dl> 589 1.1 mrg 590 1.1.1.13 mrg <br><dt><code>--enable-threads</code><dd>Specify that the target 591 1.1 mrg supports threads. This affects the Objective-C compiler and runtime 592 1.1.1.13 mrg library, and exception handling for other languages like C++. 593 1.1 mrg On some systems, this is the default. 594 1.1.1.13 mrg 595 1.1.1.13 mrg <p>In general, the best (and, in many cases, the only known) threading 596 1.1 mrg model available will be configured for use. Beware that on some 597 1.1 mrg systems, GCC has not been taught what threading models are generally 598 1.1.1.13 mrg available for the system. In this case, <samp><span class="option">--enable-threads</span></samp> is an 599 1.1.1.13 mrg alias for <samp><span class="option">--enable-threads=single</span></samp>. 600 1.1.1.13 mrg 601 1.1.1.13 mrg <br><dt><code>--disable-threads</code><dd>Specify that threading support should be disabled for the system. 602 1.1.1.13 mrg This is an alias for <samp><span class="option">--enable-threads=single</span></samp>. 603 1.1.1.13 mrg 604 1.1.1.13 mrg <br><dt><code>--enable-threads=</code><var>lib</var><dd>Specify that 605 1.1 mrg <var>lib</var> is the thread support library. This affects the Objective-C 606 1.1 mrg compiler and runtime library, and exception handling for other languages 607 1.1.1.10 mrg like C++. The possibilities for <var>lib</var> are: 608 1.1.1.13 mrg 609 1.1.1.13 mrg <dl> 610 1.1.1.13 mrg <dt><code>aix</code><dd>AIX thread support. 611 1.1.1.13 mrg <br><dt><code>dce</code><dd>DCE thread support. 612 1.1.1.13 mrg <br><dt><code>lynx</code><dd>LynxOS thread support. 613 1.1.1.13 mrg <br><dt><code>mipssde</code><dd>MIPS SDE thread support. 614 1.1.1.13 mrg <br><dt><code>no</code><dd>This is an alias for ‘<samp><span class="samp">single</span></samp>’. 615 1.1.1.13 mrg <br><dt><code>posix</code><dd>Generic POSIX/Unix98 thread support. 616 1.1.1.13 mrg <br><dt><code>rtems</code><dd>RTEMS thread support. 617 1.1.1.13 mrg <br><dt><code>single</code><dd>Disable thread support, should work for all platforms. 618 1.1.1.13 mrg <br><dt><code>tpf</code><dd>TPF thread support. 619 1.1.1.13 mrg <br><dt><code>vxworks</code><dd>VxWorks thread support. 620 1.1.1.13 mrg <br><dt><code>win32</code><dd>Microsoft Win32 API thread support. 621 1.1 mrg </dl> 622 1.1 mrg 623 1.1.1.13 mrg <br><dt><code>--enable-tls</code><dd>Specify that the target supports TLS (Thread Local Storage). Usually 624 1.1 mrg configure can correctly determine if TLS is supported. In cases where 625 1.1 mrg it guesses incorrectly, TLS can be explicitly enabled or disabled with 626 1.1.1.13 mrg <samp><span class="option">--enable-tls</span></samp> or <samp><span class="option">--disable-tls</span></samp>. This can happen if 627 1.1 mrg the assembler supports TLS but the C library does not, or if the 628 1.1 mrg assumptions made by the configure test are incorrect. 629 1.1.1.13 mrg 630 1.1.1.13 mrg <br><dt><code>--disable-tls</code><dd>Specify that the target does not support TLS. 631 1.1.1.13 mrg This is an alias for <samp><span class="option">--enable-tls=no</span></samp>. 632 1.1.1.13 mrg 633 1.1.1.13 mrg <br><dt><code>--with-cpu=</code><var>cpu</var><dt><code>--with-cpu-32=</code><var>cpu</var><dt><code>--with-cpu-64=</code><var>cpu</var><dd>Specify which cpu variant the compiler should generate code for by default. 634 1.1.1.13 mrg <var>cpu</var> will be used as the default value of the <samp><span class="option">-mcpu=</span></samp> switch. 635 1.1.1.6 mrg This option is only supported on some targets, including ARC, ARM, i386, M68k, 636 1.1.1.13 mrg PowerPC, and SPARC. It is mandatory for ARC. The <samp><span class="option">--with-cpu-32</span></samp> and 637 1.1.1.13 mrg <samp><span class="option">--with-cpu-64</span></samp> options specify separate default CPUs for 638 1.1 mrg 32-bit and 64-bit modes; these options are only supported for i386, 639 1.1.1.8 mrg x86-64, PowerPC, and SPARC. 640 1.1.1.13 mrg 641 1.1.1.13 mrg <br><dt><code>--with-schedule=</code><var>cpu</var><dt><code>--with-arch=</code><var>cpu</var><dt><code>--with-arch-32=</code><var>cpu</var><dt><code>--with-arch-64=</code><var>cpu</var><dt><code>--with-tune=</code><var>cpu</var><dt><code>--with-tune-32=</code><var>cpu</var><dt><code>--with-tune-64=</code><var>cpu</var><dt><code>--with-abi=</code><var>abi</var><dt><code>--with-fpu=</code><var>type</var><dt><code>--with-float=</code><var>type</var><dd>These configure options provide default values for the <samp><span class="option">-mschedule=</span></samp>, 642 1.1.1.13 mrg <samp><span class="option">-march=</span></samp>, <samp><span class="option">-mtune=</span></samp>, <samp><span class="option">-mabi=</span></samp>, and <samp><span class="option">-mfpu=</span></samp> 643 1.1.1.13 mrg options and for <samp><span class="option">-mhard-float</span></samp> or <samp><span class="option">-msoft-float</span></samp>. As with 644 1.1.1.13 mrg <samp><span class="option">--with-cpu</span></samp>, which switches will be accepted and acceptable values 645 1.1 mrg of the arguments depend on the target. 646 1.1.1.13 mrg 647 1.1.1.13 mrg <br><dt><code>--with-mode=</code><var>mode</var><dd>Specify if the compiler should default to <samp><span class="option">-marm</span></samp> or <samp><span class="option">-mthumb</span></samp>. 648 1.1 mrg This option is only supported on ARM targets. 649 1.1.1.13 mrg 650 1.1.1.13 mrg <br><dt><code>--with-stack-offset=</code><var>num</var><dd>This option sets the default for the -mstack-offset=<var>num</var> option, 651 1.1.1.3 skrll and will thus generally also control the setting of this option for 652 1.1.1.3 skrll libraries. This option is only supported on Epiphany targets. 653 1.1.1.13 mrg 654 1.1.1.13 mrg <br><dt><code>--with-fpmath=</code><var>isa</var><dd>This options sets <samp><span class="option">-mfpmath=sse</span></samp> by default and specifies the default 655 1.1.1.13 mrg ISA for floating-point arithmetics. You can select either ‘<samp><span class="samp">sse</span></samp>’ which 656 1.1.1.13 mrg enables <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. 657 1.1.1.3 skrll This option is only supported on i386 and x86-64 targets. 658 1.1.1.13 mrg 659 1.1.1.13 mrg <br><dt><code>--with-fp-32=</code><var>mode</var><dd>On MIPS targets, set the default value for the <samp><span class="option">-mfp</span></samp> option when using 660 1.1.1.6 mrg the o32 ABI. The possibilities for <var>mode</var> are: 661 1.1.1.13 mrg <dl> 662 1.1.1.13 mrg <dt><code>32</code><dd>Use the o32 FP32 ABI extension, as with the <samp><span class="option">-mfp32</span></samp> command-line 663 1.1.1.13 mrg option. 664 1.1.1.13 mrg <br><dt><code>xx</code><dd>Use the o32 FPXX ABI extension, as with the <samp><span class="option">-mfpxx</span></samp> command-line 665 1.1.1.13 mrg option. 666 1.1.1.13 mrg <br><dt><code>64</code><dd>Use the o32 FP64 ABI extension, as with the <samp><span class="option">-mfp64</span></samp> command-line 667 1.1.1.13 mrg option. 668 1.1.1.6 mrg </dl> 669 1.1.1.13 mrg In the absence of this configuration option the default is to use the o32 670 1.1.1.6 mrg FP32 ABI extension. 671 1.1.1.13 mrg 672 1.1.1.13 mrg <br><dt><code>--with-odd-spreg-32</code><dd>On MIPS targets, set the <samp><span class="option">-modd-spreg</span></samp> option by default when using 673 1.1.1.6 mrg the o32 ABI. 674 1.1.1.13 mrg 675 1.1.1.13 mrg <br><dt><code>--without-odd-spreg-32</code><dd>On MIPS targets, set the <samp><span class="option">-mno-odd-spreg</span></samp> option by default when using 676 1.1.1.6 mrg the o32 ABI. This is normally used in conjunction with 677 1.1.1.13 mrg <samp><span class="option">--with-fp-32=64</span></samp> in order to target the o32 FP64A ABI extension. 678 1.1.1.13 mrg 679 1.1.1.13 mrg <br><dt><code>--with-nan=</code><var>encoding</var><dd>On MIPS targets, set the default encoding convention to use for the 680 1.1.1.6 mrg special not-a-number (NaN) IEEE 754 floating-point data. The 681 1.1.1.6 mrg possibilities for <var>encoding</var> are: 682 1.1.1.13 mrg <dl> 683 1.1.1.13 mrg <dt><code>legacy</code><dd>Use the legacy encoding, as with the <samp><span class="option">-mnan=legacy</span></samp> command-line 684 1.1.1.13 mrg option. 685 1.1.1.13 mrg <br><dt><code>2008</code><dd>Use the 754-2008 encoding, as with the <samp><span class="option">-mnan=2008</span></samp> command-line 686 1.1.1.13 mrg option. 687 1.1.1.6 mrg </dl> 688 1.1.1.13 mrg To use this configuration option you must have an assembler version 689 1.1.1.13 mrg installed that supports the <samp><span class="option">-mnan=</span></samp> command-line option too. 690 1.1.1.6 mrg In the absence of this configuration option the default convention is 691 1.1.1.13 mrg the legacy encoding, as when neither of the <samp><span class="option">-mnan=2008</span></samp> and 692 1.1.1.13 mrg <samp><span class="option">-mnan=legacy</span></samp> command-line options has been used. 693 1.1.1.13 mrg 694 1.1.1.13 mrg <br><dt><code>--with-divide=</code><var>type</var><dd>Specify how the compiler should generate code for checking for 695 1.1.1.13 mrg division by zero. This option is only supported on the MIPS target. 696 1.1 mrg The possibilities for <var>type</var> are: 697 1.1.1.13 mrg <dl> 698 1.1.1.13 mrg <dt><code>traps</code><dd>Division by zero checks use conditional traps (this is the default on 699 1.1.1.13 mrg systems that support conditional traps). 700 1.1.1.13 mrg <br><dt><code>breaks</code><dd>Division by zero checks use the break instruction. 701 1.1 mrg </dl> 702 1.1 mrg 703 1.1.1.13 mrg <!-- If you make -with-llsc the default for additional targets, --> 704 1.1.1.13 mrg <!-- update the -with-llsc description in the MIPS section below. --> 705 1.1.1.13 mrg <br><dt><code>--with-llsc</code><dd>On MIPS targets, make <samp><span class="option">-mllsc</span></samp> the default when no 706 1.1.1.13 mrg <samp><span class="option">-mno-llsc</span></samp> option is passed. This is the default for 707 1.1 mrg Linux-based targets, as the kernel will emulate them if the ISA does 708 1.1 mrg not provide them. 709 1.1.1.13 mrg 710 1.1.1.13 mrg <br><dt><code>--without-llsc</code><dd>On MIPS targets, make <samp><span class="option">-mno-llsc</span></samp> the default when no 711 1.1.1.13 mrg <samp><span class="option">-mllsc</span></samp> option is passed. 712 1.1.1.13 mrg 713 1.1.1.13 mrg <br><dt><code>--with-synci</code><dd>On MIPS targets, make <samp><span class="option">-msynci</span></samp> the default when no 714 1.1.1.13 mrg <samp><span class="option">-mno-synci</span></samp> option is passed. 715 1.1.1.13 mrg 716 1.1.1.13 mrg <br><dt><code>--without-synci</code><dd>On MIPS targets, make <samp><span class="option">-mno-synci</span></samp> the default when no 717 1.1.1.13 mrg <samp><span class="option">-msynci</span></samp> option is passed. This is the default. 718 1.1.1.13 mrg 719 1.1.1.13 mrg <br><dt><code>--with-lxc1-sxc1</code><dd>On MIPS targets, make <samp><span class="option">-mlxc1-sxc1</span></samp> the default when no 720 1.1.1.13 mrg <samp><span class="option">-mno-lxc1-sxc1</span></samp> option is passed. This is the default. 721 1.1.1.13 mrg 722 1.1.1.13 mrg <br><dt><code>--without-lxc1-sxc1</code><dd>On MIPS targets, make <samp><span class="option">-mno-lxc1-sxc1</span></samp> the default when no 723 1.1.1.13 mrg <samp><span class="option">-mlxc1-sxc1</span></samp> option is passed. The indexed load/store 724 1.1.1.10 mrg instructions are not directly a problem but can lead to unexpected 725 1.1.1.10 mrg behaviour when deployed in an application intended for a 32-bit address 726 1.1.1.10 mrg space but run on a 64-bit processor. The issue is seen because all 727 1.1.1.10 mrg known MIPS 64-bit Linux kernels execute o32 and n32 applications 728 1.1.1.10 mrg with 64-bit addressing enabled which affects the overflow behaviour 729 1.1.1.10 mrg of the indexed addressing mode. GCC will assume that ordinary 730 1.1.1.10 mrg 32-bit arithmetic overflow behaviour is the same whether performed 731 1.1.1.10 mrg as an <code>addu</code> instruction or as part of the address calculation 732 1.1.1.10 mrg in <code>lwxc1</code> type instructions. This assumption holds true in a 733 1.1.1.10 mrg pure 32-bit environment and can hold true in a 64-bit environment if 734 1.1.1.10 mrg the address space is accurately set to be 32-bit for o32 and n32. 735 1.1.1.13 mrg 736 1.1.1.13 mrg <br><dt><code>--with-madd4</code><dd>On MIPS targets, make <samp><span class="option">-mmadd4</span></samp> the default when no 737 1.1.1.13 mrg <samp><span class="option">-mno-madd4</span></samp> option is passed. This is the default. 738 1.1.1.13 mrg 739 1.1.1.13 mrg <br><dt><code>--without-madd4</code><dd>On MIPS targets, make <samp><span class="option">-mno-madd4</span></samp> the default when no 740 1.1.1.13 mrg <samp><span class="option">-mmadd4</span></samp> option is passed. The <code>madd4</code> instruction 741 1.1.1.10 mrg family can be problematic when targeting a combination of cores that 742 1.1.1.10 mrg implement these instructions differently. There are two known cores 743 1.1.1.10 mrg that implement these as fused operations instead of unfused (where 744 1.1.1.10 mrg unfused is normally expected). Disabling these instructions is the 745 1.1.1.10 mrg only way to ensure compatible code is generated; this will incur 746 1.1.1.10 mrg a performance penalty. 747 1.1.1.13 mrg 748 1.1.1.13 mrg <br><dt><code>--with-mips-plt</code><dd>On MIPS targets, make use of copy relocations and PLTs. 749 1.1 mrg These features are extensions to the traditional 750 1.1 mrg SVR4-based MIPS ABIs and require support from GNU binutils 751 1.1 mrg and the runtime C library. 752 1.1.1.13 mrg 753 1.1.1.13 mrg <br><dt><code>--enable-__cxa_atexit</code><dd>Define if you want to use __cxa_atexit, rather than atexit, to 754 1.1.1.13 mrg register C++ destructors for local statics and global objects. 755 1.1 mrg This is essential for fully standards-compliant handling of 756 1.1 mrg destructors, but requires __cxa_atexit in libc. This option is currently 757 1.1 mrg only available on systems with GNU libc. When enabled, this will cause 758 1.1.1.13 mrg <samp><span class="option">-fuse-cxa-atexit</span></samp> to be passed by default. 759 1.1.1.13 mrg 760 1.1.1.13 mrg <br><dt><code>--enable-gnu-indirect-function</code><dd>Define if you want to enable the <code>ifunc</code> attribute. This option is 761 1.1.1.3 skrll currently only available on systems with GNU libc on certain targets. 762 1.1.1.13 mrg 763 1.1.1.13 mrg <br><dt><code>--enable-target-optspace</code><dd>Specify that target 764 1.1.1.13 mrg libraries should be optimized for code space instead of code speed. 765 1.1 mrg This is the default for the m32r platform. 766 1.1.1.13 mrg 767 1.1.1.13 mrg <br><dt><code>--with-cpp-install-dir=</code><var>dirname</var><dd>Specify that the user visible <samp><span class="command">cpp</span></samp> program should be installed 768 1.1.1.13 mrg in <samp><var>prefix</var><span class="file">/</span><var>dirname</var><span class="file">/cpp</span></samp>, in addition to <var>bindir</var>. 769 1.1.1.13 mrg 770 1.1.1.13 mrg <br><dt><code>--enable-comdat</code><dd>Enable COMDAT group support. This is primarily used to override the 771 1.1 mrg automatically detected value. 772 1.1.1.13 mrg 773 1.1.1.13 mrg <br><dt><code>--enable-initfini-array</code><dd>Force the use of sections <code>.init_array</code> and <code>.fini_array</code> 774 1.1 mrg (instead of <code>.init</code> and <code>.fini</code>) for constructors and 775 1.1.1.13 mrg destructors. Option <samp><span class="option">--disable-initfini-array</span></samp> has the 776 1.1 mrg opposite effect. If neither option is specified, the configure script 777 1.1 mrg will try to guess whether the <code>.init_array</code> and 778 1.1 mrg <code>.fini_array</code> sections are supported and, if they are, use them. 779 1.1.1.13 mrg 780 1.1.1.13 mrg <br><dt><code>--enable-link-mutex</code><dd>When building GCC, use a mutex to avoid linking the compilers for 781 1.1.1.6 mrg multiple languages at the same time, to avoid thrashing on build 782 1.1.1.6 mrg systems with limited free memory. The default is not to use such a mutex. 783 1.1.1.13 mrg 784 1.1.1.13 mrg <br><dt><code>--enable-maintainer-mode</code><dd>The build rules that regenerate the Autoconf and Automake output files as 785 1.1.1.13 mrg well as the GCC master message catalog <samp><span class="file">gcc.pot</span></samp> are normally 786 1.1 mrg disabled. This is because it can only be rebuilt if the complete source 787 1.1 mrg tree is present. If you have changed the sources and want to rebuild the 788 1.1.1.13 mrg catalog, configuring with <samp><span class="option">--enable-maintainer-mode</span></samp> will enable 789 1.1 mrg this. Note that you need a recent version of the <code>gettext</code> tools 790 1.1 mrg to do so. 791 1.1.1.13 mrg 792 1.1.1.13 mrg <br><dt><code>--disable-bootstrap</code><dd>For a native build, the default configuration is to perform 793 1.1.1.13 mrg a 3-stage bootstrap of the compiler when ‘<samp><span class="samp">make</span></samp>’ is invoked, 794 1.1 mrg testing that GCC can compile itself correctly. If you want to disable 795 1.1.1.13 mrg this process, you can configure with <samp><span class="option">--disable-bootstrap</span></samp>. 796 1.1.1.13 mrg 797 1.1.1.13 mrg <br><dt><code>--enable-bootstrap</code><dd>In special cases, you may want to perform a 3-stage build 798 1.1.1.13 mrg even if the target and host triplets are different. 799 1.1 mrg This is possible when the host can run code compiled for 800 1.1.1.13 mrg the target (e.g. host is i686-linux, target is i486-linux). 801 1.1 mrg Starting from GCC 4.2, to do this you have to configure explicitly 802 1.1.1.13 mrg with <samp><span class="option">--enable-bootstrap</span></samp>. 803 1.1.1.13 mrg 804 1.1.1.13 mrg <br><dt><code>--enable-generated-files-in-srcdir</code><dd>Neither the .c and .h files that are generated from Bison and flex nor the 805 1.1 mrg info manuals and man pages that are built from the .texi files are present 806 1.1.1.13 mrg in the SVN development tree. When building GCC from that development tree, 807 1.1 mrg or from one of our snapshots, those generated files are placed in your 808 1.1 mrg build directory, which allows for the source to be in a readonly 809 1.1 mrg directory. 810 1.1.1.13 mrg 811 1.1.1.13 mrg <p>If you configure with <samp><span class="option">--enable-generated-files-in-srcdir</span></samp> then those 812 1.1 mrg generated files will go into the source directory. This is mainly intended 813 1.1 mrg for generating release or prerelease tarballs of the GCC sources, since it 814 1.1 mrg is not a requirement that the users of source releases to have flex, Bison, 815 1.1 mrg or makeinfo. 816 1.1.1.13 mrg 817 1.1.1.13 mrg <br><dt><code>--enable-version-specific-runtime-libs</code><dd>Specify 818 1.1 mrg that runtime libraries should be installed in the compiler specific 819 1.1.1.13 mrg subdirectory (<samp><var>libdir</var><span class="file">/gcc</span></samp>) rather than the usual places. In 820 1.1.1.13 mrg addition, ‘<samp><span class="samp">libstdc++</span></samp>’'s include files will be installed into 821 1.1 mrg <samp><var>libdir</var></samp> unless you overruled it by using 822 1.1.1.13 mrg <samp><span class="option">--with-gxx-include-dir=</span><var>dirname</var></samp>. Using this option is 823 1.1 mrg particularly useful if you intend to use several versions of GCC in 824 1.1.1.13 mrg parallel. This is currently supported by ‘<samp><span class="samp">libgfortran</span></samp>’, 825 1.1.1.13 mrg ‘<samp><span class="samp">libstdc++</span></samp>’, and ‘<samp><span class="samp">libobjc</span></samp>’. 826 1.1.1.13 mrg 827 1.1.1.13 mrg <br><dt><code><a name="WithAixSoname"></a>--with-aix-soname=‘</code><samp><span class="samp">aix</span></samp><code>’, ‘</code><samp><span class="samp">svr4</span></samp><code>’ or ‘</code><samp><span class="samp">both</span></samp><code>’</code><dd>Traditional AIX shared library versioning (versioned <code>Shared Object</code> 828 1.1.1.6 mrg files as members of unversioned <code>Archive Library</code> files named 829 1.1.1.13 mrg ‘<samp><span class="samp">lib.a</span></samp>’) causes numerous headaches for package managers. However, 830 1.1.1.6 mrg <code>Import Files</code> as members of <code>Archive Library</code> files allow for 831 1.1.1.6 mrg <strong>filename-based versioning</strong> of shared libraries as seen on Linux/SVR4, 832 1.1.1.13 mrg where this is called the "SONAME". But as they prevent static linking, 833 1.1.1.6 mrg <code>Import Files</code> may be used with <code>Runtime Linking</code> only, where the 834 1.1.1.13 mrg linker does search for ‘<samp><span class="samp">libNAME.so</span></samp>’ before ‘<samp><span class="samp">libNAME.a</span></samp>’ library 835 1.1.1.13 mrg filenames with the ‘<samp><span class="samp">-lNAME</span></samp>’ linker flag. 836 1.1.1.13 mrg 837 1.1.1.13 mrg <p><a name="AixLdCommand"></a>For detailed information please refer to the AIX 838 1.1.1.13 mrg <a href="https://www.ibm.com/support/knowledgecenter/search/%22the%20ld%20command%2C%20also%20called%20the%20linkage%20editor%20or%20binder%22">ld Command</a> reference. 839 1.1.1.13 mrg 840 1.1.1.13 mrg <p>As long as shared library creation is enabled, upon: 841 1.1.1.13 mrg <dl> 842 1.1.1.13 mrg <dt><code>--with-aix-soname=aix</code><br><dt><code>--with-aix-soname=both</code><dd> A (traditional AIX) <code>Shared Archive Library</code> file is created: 843 1.1.1.13 mrg <ul> 844 1.1.1.13 mrg <li>using the ‘<samp><span class="samp">libNAME.a</span></samp>’ filename scheme 845 1.1.1.13 mrg <li>with the <code>Shared Object</code> file as archive member named 846 1.1.1.13 mrg ‘<samp><span class="samp">libNAME.so.V</span></samp>’ (except for ‘<samp><span class="samp">libgcc_s</span></samp>’, where the <code>Shared 847 1.1.1.13 mrg Object</code> file is named ‘<samp><span class="samp">shr.o</span></samp>’ for backwards compatibility), which 848 1.1.1.13 mrg <ul> 849 1.1.1.13 mrg <li>is used for runtime loading from inside the ‘<samp><span class="samp">libNAME.a</span></samp>’ file 850 1.1.1.13 mrg <li>is used for dynamic loading via 851 1.1.1.13 mrg <code>dlopen("libNAME.a(libNAME.so.V)", RTLD_MEMBER)</code> 852 1.1.1.13 mrg <li>is used for shared linking 853 1.1.1.13 mrg <li>is used for static linking, so no separate <code>Static Archive 854 1.1.1.6 mrg Library</code> file is needed 855 1.1.1.13 mrg </ul> 856 1.1.1.13 mrg </ul> 857 1.1.1.13 mrg <br><dt><code>--with-aix-soname=both</code><br><dt><code>--with-aix-soname=svr4</code><dd> A (second) <code>Shared Archive Library</code> file is created: 858 1.1.1.13 mrg <ul> 859 1.1.1.13 mrg <li>using the ‘<samp><span class="samp">libNAME.so.V</span></samp>’ filename scheme 860 1.1.1.13 mrg <li>with the <code>Shared Object</code> file as archive member named 861 1.1.1.13 mrg ‘<samp><span class="samp">shr.o</span></samp>’, which 862 1.1.1.13 mrg <ul> 863 1.1.1.13 mrg <li>is created with the <code>-G linker flag</code> 864 1.1.1.13 mrg <li>has the <code>F_LOADONLY</code> flag set 865 1.1.1.13 mrg <li>is used for runtime loading from inside the ‘<samp><span class="samp">libNAME.so.V</span></samp>’ file 866 1.1.1.13 mrg <li>is used for dynamic loading via <code>dlopen("libNAME.so.V(shr.o)", 867 1.1.1.6 mrg RTLD_MEMBER)</code> 868 1.1.1.13 mrg </ul> 869 1.1.1.13 mrg <li>with the <code>Import File</code> as archive member named ‘<samp><span class="samp">shr.imp</span></samp>’, 870 1.1.1.6 mrg which 871 1.1.1.13 mrg <ul> 872 1.1.1.13 mrg <li>refers to ‘<samp><span class="samp">libNAME.so.V(shr.o)</span></samp>’ as the "SONAME", to be recorded 873 1.1.1.6 mrg in the <code>Loader Section</code> of subsequent binaries 874 1.1.1.13 mrg <li>indicates whether ‘<samp><span class="samp">libNAME.so.V(shr.o)</span></samp>’ is 32 or 64 bit 875 1.1.1.13 mrg <li>lists all the public symbols exported by ‘<samp><span class="samp">lib.so.V(shr.o)</span></samp>’, 876 1.1.1.13 mrg eventually decorated with the <code>‘</code><samp><span class="samp">weak</span></samp><code>’ Keyword</code> 877 1.1.1.13 mrg <li>is necessary for shared linking against ‘<samp><span class="samp">lib.so.V(shr.o)</span></samp>’ 878 1.1.1.13 mrg </ul> 879 1.1.1.13 mrg </ul> 880 1.1.1.13 mrg A symbolic link using the ‘<samp><span class="samp">libNAME.so</span></samp>’ filename scheme is created: 881 1.1.1.13 mrg <ul> 882 1.1.1.13 mrg <li>pointing to the ‘<samp><span class="samp">libNAME.so.V</span></samp>’ <code>Shared Archive Library</code> file 883 1.1.1.13 mrg <li>to permit the <code>ld Command</code> to find ‘<samp><span class="samp">lib.so.V(shr.imp)</span></samp>’ via 884 1.1.1.13 mrg the ‘<samp><span class="samp">-lNAME</span></samp>’ argument (requires <code>Runtime Linking</code> to be enabled) 885 1.1.1.13 mrg <li>to permit dynamic loading of ‘<samp><span class="samp">lib.so.V(shr.o)</span></samp>’ without the need 886 1.1.1.13 mrg to specify the version number via <code>dlopen("libNAME.so(shr.o)", 887 1.1.1.6 mrg RTLD_MEMBER)</code> 888 1.1.1.13 mrg </ul> 889 1.1.1.13 mrg </dl> 890 1.1.1.6 mrg 891 1.1.1.13 mrg <p>As long as static library creation is enabled, upon: 892 1.1.1.13 mrg <dl> 893 1.1.1.13 mrg <dt><code>--with-aix-soname=svr4</code><dd> A <code>Static Archive Library</code> is created: 894 1.1.1.13 mrg <ul> 895 1.1.1.13 mrg <li>using the ‘<samp><span class="samp">libNAME.a</span></samp>’ filename scheme 896 1.1.1.13 mrg <li>with all the <code>Static Object</code> files as archive members, which 897 1.1.1.13 mrg <ul> 898 1.1.1.13 mrg <li>are used for static linking 899 1.1.1.13 mrg </ul> 900 1.1.1.13 mrg </ul> 901 1.1.1.13 mrg </dl> 902 1.1.1.6 mrg 903 1.1.1.13 mrg <p>While the aix-soname=‘<samp><span class="samp">svr4</span></samp>’ option does not create <code>Shared Object</code> 904 1.1.1.6 mrg files as members of unversioned <code>Archive Library</code> files any more, package 905 1.1.1.6 mrg managers still are responsible to 906 1.1.1.6 mrg <a href="./specific.html#TransferAixShobj">transfer</a> <code>Shared Object</code> files 907 1.1.1.6 mrg found as member of a previously installed unversioned <code>Archive Library</code> 908 1.1.1.6 mrg file into the newly installed <code>Archive Library</code> file with the same 909 1.1.1.6 mrg filename. 910 1.1.1.13 mrg 911 1.1.1.13 mrg <p><em>WARNING:</em> Creating <code>Shared Object</code> files with <code>Runtime Linking</code> 912 1.1.1.6 mrg enabled may bloat the TOC, eventually leading to <code>TOC overflow</code> errors, 913 1.1.1.13 mrg requiring the use of either the <samp><span class="option">-Wl,-bbigtoc</span></samp> linker flag (seen to 914 1.1.1.6 mrg break with the <code>GDB</code> debugger) or some of the TOC-related compiler flags, 915 1.1.1.6 mrg see “RS/6000 and PowerPC Options” in the main manual. 916 1.1.1.13 mrg 917 1.1.1.13 mrg <p><samp><span class="option">--with-aix-soname</span></samp> is currently supported by ‘<samp><span class="samp">libgcc_s</span></samp>’ only, so 918 1.1.1.6 mrg this option is still experimental and not for normal use yet. 919 1.1.1.13 mrg 920 1.1.1.13 mrg <p>Default is the traditional behavior <samp><span class="option">--with-aix-soname=‘</span><samp><span class="samp">aix</span></samp><span class="option">’</span></samp>. 921 1.1.1.13 mrg 922 1.1.1.13 mrg <br><dt><code>--enable-languages=</code><var>lang1</var><code>,</code><var>lang2</var><code>,...</code><dd>Specify that only a particular subset of compilers and 923 1.1 mrg their runtime libraries should be built. For a list of valid values for 924 1.1 mrg <var>langN</var> you can issue the following command in the 925 1.1.1.13 mrg <samp><span class="file">gcc</span></samp> directory of your GCC source tree:<br> 926 1.1.1.13 mrg <pre class="smallexample"> grep ^language= */config-lang.in 927 1.1.1.13 mrg </pre> 928 1.1.1.13 mrg <p>Currently, you can use any of the following: 929 1.1.1.13 mrg <code>all</code>, <code>ada</code>, <code>c</code>, <code>c++</code>, <code>fortran</code>, 930 1.1.1.13 mrg <code>go</code>, <code>jit</code>, <code>lto</code>, <code>objc</code>, <code>obj-c++</code>. 931 1.1.1.13 mrg Building the Ada compiler has special requirements, see below. 932 1.1.1.13 mrg If you do not pass this flag, or specify the option <code>all</code>, then all 933 1.1.1.13 mrg default languages available in the <samp><span class="file">gcc</span></samp> sub-tree will be configured. 934 1.1.1.8 mrg Ada, Go, Jit, and Objective-C++ are not default languages. LTO is not a 935 1.1.1.13 mrg default language, but is built by default because <samp><span class="option">--enable-lto</span></samp> is 936 1.1.1.13 mrg enabled by default. The other languages are default languages. 937 1.1.1.13 mrg 938 1.1.1.13 mrg <br><dt><code>--enable-stage1-languages=</code><var>lang1</var><code>,</code><var>lang2</var><code>,...</code><dd>Specify that a particular subset of compilers and their runtime 939 1.1 mrg libraries should be built with the system C compiler during stage 1 of 940 1.1 mrg the bootstrap process, rather than only in later stages with the 941 1.1 mrg bootstrapped C compiler. The list of valid values is the same as for 942 1.1.1.13 mrg <samp><span class="option">--enable-languages</span></samp>, and the option <code>all</code> will select all 943 1.1.1.13 mrg of the languages enabled by <samp><span class="option">--enable-languages</span></samp>. This option is 944 1.1 mrg primarily useful for GCC development; for instance, when a development 945 1.1 mrg version of the compiler cannot bootstrap due to compiler bugs, or when 946 1.1 mrg one is debugging front ends other than the C front end. When this 947 1.1 mrg option is used, one can then build the target libraries for the 948 1.1.1.13 mrg specified languages with the stage-1 compiler by using <samp><span class="command">make 949 1.1.1.13 mrg stage1-bubble all-target</span></samp>, or run the testsuite on the stage-1 compiler 950 1.1.1.13 mrg for the specified languages using <samp><span class="command">make stage1-start check-gcc</span></samp>. 951 1.1.1.13 mrg 952 1.1.1.13 mrg <br><dt><code>--disable-libada</code><dd>Specify that the run-time libraries and tools used by GNAT should not 953 1.1 mrg be built. This can be useful for debugging, or for compatibility with 954 1.1 mrg previous Ada build procedures, when it was required to explicitly 955 1.1.1.13 mrg do a ‘<samp><span class="samp">make -C gcc gnatlib_and_tools</span></samp>’. 956 1.1.1.13 mrg 957 1.1.1.13 mrg <br><dt><code>--disable-libsanitizer</code><dd>Specify that the run-time libraries for the various sanitizers should 958 1.1.1.6 mrg not be built. 959 1.1.1.13 mrg 960 1.1.1.13 mrg <br><dt><code>--disable-libssp</code><dd>Specify that the run-time libraries for stack smashing protection 961 1.1.1.13 mrg should not be built. 962 1.1.1.13 mrg 963 1.1.1.13 mrg <br><dt><code>--disable-libquadmath</code><dd>Specify that the GCC quad-precision math library should not be built. 964 1.1.1.3 skrll On some systems, the library is required to be linkable when building 965 1.1.1.13 mrg the Fortran front end, unless <samp><span class="option">--disable-libquadmath-support</span></samp> 966 1.1.1.3 skrll is used. 967 1.1.1.13 mrg 968 1.1.1.13 mrg <br><dt><code>--disable-libquadmath-support</code><dd>Specify that the Fortran front end and <code>libgfortran</code> do not add 969 1.1.1.3 skrll support for <code>libquadmath</code> on systems supporting it. 970 1.1.1.13 mrg 971 1.1.1.13 mrg <br><dt><code>--disable-libgomp</code><dd>Specify that the GNU Offloading and Multi Processing Runtime Library 972 1.1.1.6 mrg should not be built. 973 1.1.1.13 mrg 974 1.1.1.13 mrg <br><dt><code>--disable-libvtv</code><dd>Specify that the run-time libraries used by vtable verification 975 1.1.1.6 mrg should not be built. 976 1.1.1.13 mrg 977 1.1.1.13 mrg <br><dt><code>--with-dwarf2</code><dd>Specify that the compiler should 978 1.1 mrg use DWARF 2 debugging information as the default. 979 1.1.1.13 mrg 980 1.1.1.13 mrg <br><dt><code>--with-advance-toolchain=</code><var>at</var><dd>On 64-bit PowerPC Linux systems, configure the compiler to use the 981 1.1.1.8 mrg header files, library files, and the dynamic linker from the Advance 982 1.1.1.8 mrg Toolchain release <var>at</var> instead of the default versions that are 983 1.1.1.8 mrg provided by the Linux distribution. In general, this option is 984 1.1.1.8 mrg intended for the developers of GCC, and it is not intended for general 985 1.1.1.8 mrg use. 986 1.1.1.13 mrg 987 1.1.1.13 mrg <br><dt><code>--enable-targets=all</code><dt><code>--enable-targets=</code><var>target_list</var><dd>Some GCC targets, e.g. powerpc64-linux, build bi-arch compilers. 988 1.1 mrg These are compilers that are able to generate either 64-bit or 32-bit 989 1.1.1.13 mrg code. Typically, the corresponding 32-bit target, e.g. 990 1.1 mrg powerpc-linux for powerpc64-linux, only generates 32-bit code. This 991 1.1 mrg option enables the 32-bit target to be a bi-arch compiler, which is 992 1.1 mrg useful when you want a bi-arch compiler that defaults to 32-bit, and 993 1.1.1.13 mrg you are building a bi-arch or multi-arch binutils in a combined tree. 994 1.1 mrg On mips-linux, this will build a tri-arch compiler (ABI o32/n32/64), 995 1.1.1.13 mrg defaulted to o32. 996 1.1.1.3 skrll Currently, this option only affects sparc-linux, powerpc-linux, x86-linux, 997 1.1.1.3 skrll mips-linux and s390-linux. 998 1.1.1.13 mrg 999 1.1.1.13 mrg <br><dt><code>--enable-default-pie</code><dd>Turn on <samp><span class="option">-fPIE</span></samp> and <samp><span class="option">-pie</span></samp> by default. 1000 1.1.1.13 mrg 1001 1.1.1.13 mrg <br><dt><code>--enable-secureplt</code><dd>This option enables <samp><span class="option">-msecure-plt</span></samp> by default for powerpc-linux. 1002 1.1 mrg See “RS/6000 and PowerPC Options” in the main manual 1003 1.1.1.13 mrg 1004 1.1.1.13 mrg <br><dt><code>--enable-default-ssp</code><dd>Turn on <samp><span class="option">-fstack-protector-strong</span></samp> by default. 1005 1.1.1.13 mrg 1006 1.1.1.13 mrg <br><dt><code>--enable-cld</code><dd>This option enables <samp><span class="option">-mcld</span></samp> by default for 32-bit x86 targets. 1007 1.1 mrg See “i386 and x86-64 Options” in the main manual 1008 1.1.1.13 mrg 1009 1.1.1.13 mrg <br><dt><code>--enable-win32-registry</code><dt><code>--enable-win32-registry=</code><var>key</var><dt><code>--disable-win32-registry</code><dd>The <samp><span class="option">--enable-win32-registry</span></samp> option enables Microsoft Windows-hosted GCC 1010 1.1 mrg to look up installations paths in the registry using the following key: 1011 1.1 mrg 1012 1.1.1.13 mrg <pre class="smallexample"> <code>HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\</code><var>key</var> 1013 1.1.1.13 mrg </pre> 1014 1.1.1.13 mrg <p><var>key</var> defaults to GCC version number, and can be overridden by the 1015 1.1.1.13 mrg <samp><span class="option">--enable-win32-registry=</span><var>key</var></samp> option. Vendors and distributors 1016 1.1 mrg who use custom installers are encouraged to provide a different key, 1017 1.1 mrg perhaps one comprised of vendor name and GCC version number, to 1018 1.1 mrg avoid conflict with existing installations. This feature is enabled 1019 1.1.1.13 mrg by default, and can be disabled by <samp><span class="option">--disable-win32-registry</span></samp> 1020 1.1 mrg option. This option has no effect on the other hosts. 1021 1.1.1.13 mrg 1022 1.1.1.13 mrg <br><dt><code>--nfp</code><dd>Specify that the machine does not have a floating point unit. This 1023 1.1.1.13 mrg option only applies to ‘<samp><span class="samp">m68k-sun-sunos</span><var>n</var></samp>’. On any other 1024 1.1.1.13 mrg system, <samp><span class="option">--nfp</span></samp> has no effect. 1025 1.1.1.13 mrg 1026 1.1.1.13 mrg <br><dt><code>--enable-werror</code><dt><code>--disable-werror</code><dt><code>--enable-werror=yes</code><dt><code>--enable-werror=no</code><dd>When you specify this option, it controls whether certain files in the 1027 1.1.1.13 mrg compiler are built with <samp><span class="option">-Werror</span></samp> in bootstrap stage2 and later. 1028 1.1.1.13 mrg If you don't specify it, <samp><span class="option">-Werror</span></samp> is turned on for the main 1029 1.1 mrg development trunk. However it defaults to off for release branches and 1030 1.1.1.13 mrg final releases. The specific files which get <samp><span class="option">-Werror</span></samp> are 1031 1.1 mrg controlled by the Makefiles. 1032 1.1.1.13 mrg 1033 1.1.1.13 mrg <br><dt><code>--enable-checking</code><dt><code>--enable-checking=</code><var>list</var><dd>When you specify this option, the compiler is built to perform internal 1034 1.1.1.13 mrg consistency checks of the requested complexity. This does not change the 1035 1.1.1.13 mrg generated code, but adds error checking within the compiler. This will 1036 1.1.1.13 mrg slow down the compiler and may only work properly if you are building 1037 1.1.1.13 mrg the compiler with GCC. This is ‘<samp><span class="samp">yes,extra</span></samp>’ by default when building 1038 1.1.1.13 mrg from SVN or snapshots, but ‘<samp><span class="samp">release</span></samp>’ for releases. The default 1039 1.1.1.13 mrg for building the stage1 compiler is ‘<samp><span class="samp">yes</span></samp>’. More control 1040 1.1.1.13 mrg over the checks may be had by specifying <var>list</var>. The categories of 1041 1.1.1.13 mrg checks available are ‘<samp><span class="samp">yes</span></samp>’ (most common checks 1042 1.1.1.13 mrg ‘<samp><span class="samp">assert,misc,tree,gc,rtlflag,runtime</span></samp>’), ‘<samp><span class="samp">no</span></samp>’ (no checks at 1043 1.1.1.13 mrg all), ‘<samp><span class="samp">all</span></samp>’ (all but ‘<samp><span class="samp">valgrind</span></samp>’), ‘<samp><span class="samp">release</span></samp>’ (cheapest 1044 1.1.1.13 mrg checks ‘<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>’). 1045 1.1.1.13 mrg Individual checks can be enabled with these flags ‘<samp><span class="samp">assert</span></samp>’, 1046 1.1.1.13 mrg ‘<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>’, 1047 1.1.1.13 mrg ‘<samp><span class="samp">rtlflag</span></samp>’, ‘<samp><span class="samp">runtime</span></samp>’, ‘<samp><span class="samp">tree</span></samp>’, ‘<samp><span class="samp">extra</span></samp>’ and ‘<samp><span class="samp">valgrind</span></samp>’. 1048 1.1.1.13 mrg ‘<samp><span class="samp">extra</span></samp>’ adds for ‘<samp><span class="samp">misc</span></samp>’ checking extra checks that might affect 1049 1.1.1.13 mrg code generation and should therefore not differ between stage1 and later 1050 1.1.1.13 mrg stages. 1051 1.1.1.13 mrg 1052 1.1.1.13 mrg <p>The ‘<samp><span class="samp">valgrind</span></samp>’ check requires the external <samp><span class="command">valgrind</span></samp> 1053 1.1.1.13 mrg simulator, available from <a href="http://valgrind.org/">http://valgrind.org/</a>. The 1054 1.1.1.13 mrg ‘<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. 1055 1.1.1.13 mrg To disable all checking, ‘<samp><span class="samp">--disable-checking</span></samp>’ or 1056 1.1.1.13 mrg ‘<samp><span class="samp">--enable-checking=none</span></samp>’ must be explicitly requested. Disabling 1057 1.1.1.13 mrg assertions will make the compiler and runtime slightly faster but 1058 1.1.1.13 mrg increase the risk of undetected internal errors causing wrong code to be 1059 1.1.1.13 mrg generated. 1060 1.1.1.13 mrg 1061 1.1.1.13 mrg <br><dt><code>--disable-stage1-checking</code><dt><code>--enable-stage1-checking</code><dt><code>--enable-stage1-checking=</code><var>list</var><dd>If no <samp><span class="option">--enable-checking</span></samp> option is specified the stage1 1062 1.1.1.13 mrg compiler will be built with ‘<samp><span class="samp">yes</span></samp>’ checking enabled, otherwise 1063 1.1.1.13 mrg the stage1 checking flags are the same as specified by 1064 1.1.1.13 mrg <samp><span class="option">--enable-checking</span></samp>. To build the stage1 compiler with 1065 1.1.1.13 mrg different checking options use <samp><span class="option">--enable-stage1-checking</span></samp>. 1066 1.1.1.13 mrg The list of checking options is the same as for <samp><span class="option">--enable-checking</span></samp>. 1067 1.1 mrg If your system is too slow or too small to bootstrap a released compiler 1068 1.1.1.13 mrg with checking for stage1 enabled, you can use ‘<samp><span class="samp">--disable-stage1-checking</span></samp>’ 1069 1.1 mrg to disable checking for the stage1 compiler. 1070 1.1.1.13 mrg 1071 1.1.1.13 mrg <br><dt><code>--enable-coverage</code><dt><code>--enable-coverage=</code><var>level</var><dd>With this option, the compiler is built to collect self coverage 1072 1.1 mrg information, every time it is run. This is for internal development 1073 1.1 mrg purposes, and only works when the compiler is being built with gcc. The 1074 1.1 mrg <var>level</var> argument controls whether the compiler is built optimized or 1075 1.1.1.13 mrg not, values are ‘<samp><span class="samp">opt</span></samp>’ and ‘<samp><span class="samp">noopt</span></samp>’. For coverage analysis you 1076 1.1 mrg want to disable optimization, for performance analysis you want to 1077 1.1 mrg enable optimization. When coverage is enabled, the default level is 1078 1.1 mrg without optimization. 1079 1.1.1.13 mrg 1080 1.1.1.13 mrg <br><dt><code>--enable-gather-detailed-mem-stats</code><dd>When this option is specified more detailed information on memory 1081 1.1 mrg allocation is gathered. This information is printed when using 1082 1.1.1.13 mrg <samp><span class="option">-fmem-report</span></samp>. 1083 1.1.1.13 mrg 1084 1.1.1.13 mrg <br><dt><code>--enable-valgrind-annotations</code><dd>Mark selected memory related operations in the compiler when run under 1085 1.1.1.8 mrg valgrind to suppress false positives. 1086 1.1.1.13 mrg 1087 1.1.1.13 mrg <br><dt><code>--enable-nls</code><dt><code>--disable-nls</code><dd>The <samp><span class="option">--enable-nls</span></samp> option enables Native Language Support (NLS), 1088 1.1 mrg which lets GCC output diagnostics in languages other than American 1089 1.1 mrg English. Native Language Support is enabled by default if not doing a 1090 1.1.1.13 mrg canadian cross build. The <samp><span class="option">--disable-nls</span></samp> option disables NLS. 1091 1.1.1.13 mrg 1092 1.1.1.13 mrg <br><dt><code>--with-included-gettext</code><dd>If NLS is enabled, the <samp><span class="option">--with-included-gettext</span></samp> option causes the build 1093 1.1.1.13 mrg procedure to prefer its copy of GNU <samp><span class="command">gettext</span></samp>. 1094 1.1.1.13 mrg 1095 1.1.1.13 mrg <br><dt><code>--with-catgets</code><dd>If NLS is enabled, and if the host lacks <code>gettext</code> but has the 1096 1.1 mrg inferior <code>catgets</code> interface, the GCC build procedure normally 1097 1.1.1.13 mrg ignores <code>catgets</code> and instead uses GCC's copy of the GNU 1098 1.1.1.13 mrg <code>gettext</code> library. The <samp><span class="option">--with-catgets</span></samp> option causes the 1099 1.1.1.13 mrg build procedure to use the host's <code>catgets</code> in this situation. 1100 1.1.1.13 mrg 1101 1.1.1.13 mrg <br><dt><code>--with-libiconv-prefix=</code><var>dir</var><dd>Search for libiconv header files in <samp><var>dir</var><span class="file">/include</span></samp> and 1102 1.1.1.13 mrg libiconv library files in <samp><var>dir</var><span class="file">/lib</span></samp>. 1103 1.1.1.13 mrg 1104 1.1.1.13 mrg <br><dt><code>--enable-obsolete</code><dd>Enable configuration for an obsoleted system. If you attempt to 1105 1.1 mrg configure GCC for a system (build, host, or target) which has been 1106 1.1 mrg obsoleted, and you do not specify this flag, configure will halt with an 1107 1.1 mrg error message. 1108 1.1.1.13 mrg 1109 1.1.1.13 mrg <p>All support for systems which have been obsoleted in one release of GCC 1110 1.1 mrg is removed entirely in the next major release, unless someone steps 1111 1.1 mrg forward to maintain the port. 1112 1.1.1.13 mrg 1113 1.1.1.13 mrg <br><dt><code>--enable-decimal-float</code><dt><code>--enable-decimal-float=yes</code><dt><code>--enable-decimal-float=no</code><dt><code>--enable-decimal-float=bid</code><dt><code>--enable-decimal-float=dpd</code><dt><code>--disable-decimal-float</code><dd>Enable (or disable) support for the C decimal floating point extension 1114 1.1 mrg that is in the IEEE 754-2008 standard. This is enabled by default only 1115 1.1 mrg on PowerPC, i386, and x86_64 GNU/Linux systems. Other systems may also 1116 1.1 mrg support it, but require the user to specifically enable it. You can 1117 1.1 mrg optionally control which decimal floating point format is used (either 1118 1.1.1.13 mrg ‘<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) 1119 1.1.1.13 mrg format is default on i386 and x86_64 systems, and the ‘<samp><span class="samp">dpd</span></samp>’ 1120 1.1 mrg (densely packed decimal) format is default on PowerPC systems. 1121 1.1.1.13 mrg 1122 1.1.1.13 mrg <br><dt><code>--enable-fixed-point</code><dt><code>--disable-fixed-point</code><dd>Enable (or disable) support for C fixed-point arithmetic. 1123 1.1 mrg This option is enabled by default for some targets (such as MIPS) which 1124 1.1 mrg have hardware-support for fixed-point operations. On other targets, you 1125 1.1 mrg may enable this option manually. 1126 1.1.1.13 mrg 1127 1.1.1.13 mrg <br><dt><code>--with-long-double-128</code><dd>Specify if <code>long double</code> type should be 128-bit by default on selected 1128 1.1 mrg GNU/Linux architectures. If using <code>--without-long-double-128</code>, 1129 1.1.1.13 mrg <code>long double</code> will be by default 64-bit, the same as <code>double</code> type. 1130 1.1 mrg When neither of these configure options are used, the default will be 1131 1.1 mrg 128-bit <code>long double</code> when built against GNU C Library 2.4 and later, 1132 1.1 mrg 64-bit <code>long double</code> otherwise. 1133 1.1.1.13 mrg 1134 1.1.1.13 mrg <br><dt><code>--enable-fdpic</code><dd>On SH Linux systems, generate ELF FDPIC code. 1135 1.1.1.13 mrg 1136 1.1.1.13 mrg <br><dt><code>--with-gmp=</code><var>pathname</var><dt><code>--with-gmp-include=</code><var>pathname</var><dt><code>--with-gmp-lib=</code><var>pathname</var><dt><code>--with-mpfr=</code><var>pathname</var><dt><code>--with-mpfr-include=</code><var>pathname</var><dt><code>--with-mpfr-lib=</code><var>pathname</var><dt><code>--with-mpc=</code><var>pathname</var><dt><code>--with-mpc-include=</code><var>pathname</var><dt><code>--with-mpc-lib=</code><var>pathname</var><dd>If you want to build GCC but do not have the GMP library, the MPFR 1137 1.1 mrg library and/or the MPC library installed in a standard location and 1138 1.1.1.3 skrll do not have their sources present in the GCC source tree then you 1139 1.1.1.3 skrll can explicitly specify the directory where they are installed 1140 1.1.1.13 mrg (‘<samp><span class="samp">--with-gmp=</span><var>gmpinstalldir</var></samp>’, 1141 1.1.1.13 mrg ‘<samp><span class="samp">--with-mpfr=</span><var>mpfrinstalldir</var></samp>’, 1142 1.1.1.13 mrg ‘<samp><span class="samp">--with-mpc=</span><var>mpcinstalldir</var></samp>’). The 1143 1.1.1.13 mrg <samp><span class="option">--with-gmp=</span><var>gmpinstalldir</var></samp> option is shorthand for 1144 1.1.1.13 mrg <samp><span class="option">--with-gmp-lib=</span><var>gmpinstalldir</var><span class="option">/lib</span></samp> and 1145 1.1.1.13 mrg <samp><span class="option">--with-gmp-include=</span><var>gmpinstalldir</var><span class="option">/include</span></samp>. Likewise the 1146 1.1.1.13 mrg <samp><span class="option">--with-mpfr=</span><var>mpfrinstalldir</var></samp> option is shorthand for 1147 1.1.1.13 mrg <samp><span class="option">--with-mpfr-lib=</span><var>mpfrinstalldir</var><span class="option">/lib</span></samp> and 1148 1.1.1.13 mrg <samp><span class="option">--with-mpfr-include=</span><var>mpfrinstalldir</var><span class="option">/include</span></samp>, also the 1149 1.1.1.13 mrg <samp><span class="option">--with-mpc=</span><var>mpcinstalldir</var></samp> option is shorthand for 1150 1.1.1.13 mrg <samp><span class="option">--with-mpc-lib=</span><var>mpcinstalldir</var><span class="option">/lib</span></samp> and 1151 1.1.1.13 mrg <samp><span class="option">--with-mpc-include=</span><var>mpcinstalldir</var><span class="option">/include</span></samp>. If these 1152 1.1 mrg shorthand assumptions are not correct, you can use the explicit 1153 1.1.1.3 skrll include and lib options directly. You might also need to ensure the 1154 1.1.1.3 skrll shared libraries can be found by the dynamic linker when building and 1155 1.1.1.3 skrll using GCC, for example by setting the runtime shared library path 1156 1.1.1.13 mrg variable (<samp><span class="env">LD_LIBRARY_PATH</span></samp> on GNU/Linux and Solaris systems). 1157 1.1.1.13 mrg 1158 1.1.1.13 mrg <p>These flags are applicable to the host platform only. When building 1159 1.1.1.3 skrll a cross compiler, they will not be used to configure target libraries. 1160 1.1.1.13 mrg 1161 1.1.1.13 mrg <br><dt><code>--with-isl=</code><var>pathname</var><dt><code>--with-isl-include=</code><var>pathname</var><dt><code>--with-isl-lib=</code><var>pathname</var><dd>If you do not have the isl library installed in a standard location and you 1162 1.1.1.6 mrg want to build GCC, you can explicitly specify the directory where it is 1163 1.1.1.13 mrg installed (‘<samp><span class="samp">--with-isl=</span><var>islinstalldir</var></samp>’). The 1164 1.1.1.13 mrg <samp><span class="option">--with-isl=</span><var>islinstalldir</var></samp> option is shorthand for 1165 1.1.1.13 mrg <samp><span class="option">--with-isl-lib=</span><var>islinstalldir</var><span class="option">/lib</span></samp> and 1166 1.1.1.13 mrg <samp><span class="option">--with-isl-include=</span><var>islinstalldir</var><span class="option">/include</span></samp>. If this 1167 1.1.1.6 mrg shorthand assumption is not correct, you can use the explicit 1168 1.1 mrg include and lib options directly. 1169 1.1.1.13 mrg 1170 1.1.1.13 mrg <p>These flags are applicable to the host platform only. When building 1171 1.1.1.3 skrll a cross compiler, they will not be used to configure target libraries. 1172 1.1.1.13 mrg 1173 1.1.1.13 mrg <br><dt><code>--with-stage1-ldflags=</code><var>flags</var><dd>This option may be used to set linker flags to be used when linking 1174 1.1 mrg stage 1 of GCC. These are also used when linking GCC if configured with 1175 1.1.1.13 mrg <samp><span class="option">--disable-bootstrap</span></samp>. If <samp><span class="option">--with-stage1-libs</span></samp> is not set to a 1176 1.1.1.13 mrg value, then the default is ‘<samp><span class="samp">-static-libstdc++ -static-libgcc</span></samp>’, if 1177 1.1.1.8 mrg supported. 1178 1.1.1.13 mrg 1179 1.1.1.13 mrg <br><dt><code>--with-stage1-libs=</code><var>libs</var><dd>This option may be used to set libraries to be used when linking stage 1 1180 1.1 mrg of GCC. These are also used when linking GCC if configured with 1181 1.1.1.13 mrg <samp><span class="option">--disable-bootstrap</span></samp>. 1182 1.1.1.13 mrg 1183 1.1.1.13 mrg <br><dt><code>--with-boot-ldflags=</code><var>flags</var><dd>This option may be used to set linker flags to be used when linking 1184 1.1.1.8 mrg stage 2 and later when bootstrapping GCC. If –with-boot-libs 1185 1.1.1.8 mrg is not is set to a value, then the default is 1186 1.1.1.13 mrg ‘<samp><span class="samp">-static-libstdc++ -static-libgcc</span></samp>’. 1187 1.1.1.13 mrg 1188 1.1.1.13 mrg <br><dt><code>--with-boot-libs=</code><var>libs</var><dd>This option may be used to set libraries to be used when linking stage 2 1189 1.1.1.8 mrg and later when bootstrapping GCC. 1190 1.1.1.13 mrg 1191 1.1.1.13 mrg <br><dt><code>--with-debug-prefix-map=</code><var>map</var><dd>Convert source directory names using <samp><span class="option">-fdebug-prefix-map</span></samp> when 1192 1.1 mrg building runtime libraries. ‘<samp><var>map</var></samp>’ is a space-separated 1193 1.1.1.13 mrg list of maps of the form ‘<samp><var>old</var><span class="samp">=</span><var>new</var></samp>’. 1194 1.1.1.13 mrg 1195 1.1.1.13 mrg <br><dt><code>--enable-linker-build-id</code><dd>Tells GCC to pass <samp><span class="option">--build-id</span></samp> option to the linker for all final 1196 1.1.1.13 mrg links (links performed without the <samp><span class="option">-r</span></samp> or <samp><span class="option">--relocatable</span></samp> 1197 1.1 mrg option), if the linker supports it. If you specify 1198 1.1.1.13 mrg <samp><span class="option">--enable-linker-build-id</span></samp>, but your linker does not 1199 1.1.1.13 mrg support <samp><span class="option">--build-id</span></samp> option, a warning is issued and the 1200 1.1.1.13 mrg <samp><span class="option">--enable-linker-build-id</span></samp> option is ignored. The default is off. 1201 1.1.1.13 mrg 1202 1.1.1.13 mrg <br><dt><code>--with-linker-hash-style=</code><var>choice</var><dd>Tells GCC to pass <samp><span class="option">--hash-style=</span><var>choice</var></samp> option to the 1203 1.1.1.3 skrll linker for all final links. <var>choice</var> can be one of 1204 1.1.1.13 mrg ‘<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. 1205 1.1.1.13 mrg 1206 1.1.1.13 mrg <br><dt><code>--enable-gnu-unique-object</code><dt><code>--disable-gnu-unique-object</code><dd>Tells GCC to use the gnu_unique_object relocation for C++ template 1207 1.1 mrg static data members and inline function local statics. Enabled by 1208 1.1.1.6 mrg default for a toolchain with an assembler that accepts it and 1209 1.1 mrg GLIBC 2.11 or above, otherwise disabled. 1210 1.1.1.13 mrg 1211 1.1.1.13 mrg <br><dt><code>--with-diagnostics-color=</code><var>choice</var><dd>Tells GCC to use <var>choice</var> as the default for <samp><span class="option">-fdiagnostics-color=</span></samp> 1212 1.1.1.6 mrg option (if not used explicitly on the command line). <var>choice</var> 1213 1.1.1.13 mrg can be one of ‘<samp><span class="samp">never</span></samp>’, ‘<samp><span class="samp">auto</span></samp>’, ‘<samp><span class="samp">always</span></samp>’, and ‘<samp><span class="samp">auto-if-env</span></samp>’ 1214 1.1.1.13 mrg where ‘<samp><span class="samp">auto</span></samp>’ is the default. ‘<samp><span class="samp">auto-if-env</span></samp>’ means that 1215 1.1.1.13 mrg <samp><span class="option">-fdiagnostics-color=auto</span></samp> will be the default if <code>GCC_COLORS</code> 1216 1.1.1.6 mrg is present and non-empty in the environment, and 1217 1.1.1.13 mrg <samp><span class="option">-fdiagnostics-color=never</span></samp> otherwise. 1218 1.1.1.13 mrg 1219 1.1.1.13 mrg <br><dt><code>--enable-lto</code><dt><code>--disable-lto</code><dd>Enable support for link-time optimization (LTO). This is enabled by 1220 1.1.1.13 mrg default, and may be disabled using <samp><span class="option">--disable-lto</span></samp>. 1221 1.1.1.13 mrg 1222 1.1.1.13 mrg <br><dt><code>--enable-linker-plugin-configure-flags=FLAGS</code><dt><code>--enable-linker-plugin-flags=FLAGS</code><dd>By default, linker plugins (such as the LTO plugin) are built for the 1223 1.1.1.6 mrg host system architecture. For the case that the linker has a 1224 1.1.1.6 mrg different (but run-time compatible) architecture, these flags can be 1225 1.1.1.6 mrg specified to build plugins that are compatible to the linker. For 1226 1.1.1.6 mrg example, if you are building GCC for a 64-bit x86_64 1227 1.1.1.13 mrg (‘<samp><span class="samp">x86_64-unknown-linux-gnu</span></samp>’) host system, but have a 32-bit x86 1228 1.1.1.13 mrg GNU/Linux (‘<samp><span class="samp">i686-pc-linux-gnu</span></samp>’) linker executable (which is 1229 1.1.1.6 mrg executable on the former system), you can configure GCC as follows for 1230 1.1.1.6 mrg getting compatible linker plugins: 1231 1.1.1.13 mrg 1232 1.1.1.13 mrg <pre class="smallexample"> % <var>srcdir</var>/configure \ 1233 1.1.1.13 mrg --host=x86_64-unknown-linux-gnu \ 1234 1.1.1.13 mrg --enable-linker-plugin-configure-flags=--host=i686-pc-linux-gnu \ 1235 1.1.1.13 mrg --enable-linker-plugin-flags='CC=gcc\ -m32\ -Wl,-rpath,[...]/i686-pc-linux-gnu/lib' 1236 1.1.1.13 mrg </pre> 1237 1.1.1.13 mrg <br><dt><code>--with-plugin-ld=</code><var>pathname</var><dd>Enable an alternate linker to be used at link-time optimization (LTO) 1238 1.1.1.13 mrg link time when <samp><span class="option">-fuse-linker-plugin</span></samp> is enabled. 1239 1.1.1.3 skrll This linker should have plugin support such as gold starting with 1240 1.1.1.13 mrg version 2.20 or GNU ld starting with version 2.21. 1241 1.1.1.13 mrg See <samp><span class="option">-fuse-linker-plugin</span></samp> for details. 1242 1.1.1.13 mrg 1243 1.1.1.13 mrg <br><dt><code>--enable-canonical-system-headers</code><dt><code>--disable-canonical-system-headers</code><dd>Enable system header path canonicalization for <samp><span class="file">libcpp</span></samp>. This can 1244 1.1.1.3 skrll produce shorter header file paths in diagnostics and dependency output 1245 1.1.1.3 skrll files, but these changed header paths may conflict with some compilation 1246 1.1.1.3 skrll environments. Enabled by default, and may be disabled using 1247 1.1.1.13 mrg <samp><span class="option">--disable-canonical-system-headers</span></samp>. 1248 1.1.1.13 mrg 1249 1.1.1.13 mrg <br><dt><code>--with-glibc-version=</code><var>major</var><code>.</code><var>minor</var><dd>Tell GCC that when the GNU C Library (glibc) is used on the target it 1250 1.1.1.6 mrg will be version <var>major</var>.<var>minor</var> or later. Normally this can 1251 1.1.1.13 mrg be detected from the C library's header files, but this option may be 1252 1.1.1.6 mrg needed when bootstrapping a cross toolchain without the header files 1253 1.1.1.6 mrg available for building the initial bootstrap compiler. 1254 1.1.1.13 mrg 1255 1.1.1.13 mrg <p>If GCC is configured with some multilibs that use glibc and some that 1256 1.1.1.13 mrg do not, this option applies only to the multilibs that use glibc. 1257 1.1.1.6 mrg However, such configurations may not work well as not all the relevant 1258 1.1.1.6 mrg configuration in GCC is on a per-multilib basis. 1259 1.1.1.13 mrg 1260 1.1.1.13 mrg <br><dt><code>--enable-as-accelerator-for=</code><var>target</var><dd>Build as offload target compiler. Specify offload host triple by <var>target</var>. 1261 1.1.1.13 mrg 1262 1.1.1.13 mrg <br><dt><code>--enable-offload-targets=</code><var>target1</var><code>[=</code><var>path1</var><code>],...,</code><var>targetN</var><code>[=</code><var>pathN</var><code>]</code><dd>Enable offloading to targets <var>target1</var>, <small class="dots">...</small>, <var>targetN</var>. 1263 1.1.1.6 mrg Offload compilers are expected to be already installed. Default search 1264 1.1.1.6 mrg path for them is <samp><var>exec-prefix</var></samp>, but it can be changed by 1265 1.1.1.13 mrg specifying paths <var>path1</var>, <small class="dots">...</small>, <var>pathN</var>. 1266 1.1.1.8 mrg 1267 1.1.1.13 mrg <pre class="smallexample"> % <var>srcdir</var>/configure \ 1268 1.1.1.13 mrg --enable-offload-target=i686-unknown-linux-gnu=/path/to/i686/compiler,x86_64-pc-linux-gnu 1269 1.1.1.13 mrg </pre> 1270 1.1.1.13 mrg <p>If ‘<samp><span class="samp">hsa</span></samp>’ is specified as one of the targets, the compiler will be 1271 1.1.1.8 mrg built with support for HSA GPU accelerators. Because the same 1272 1.1.1.8 mrg compiler will emit the accelerator code, no path should be specified. 1273 1.1.1.13 mrg 1274 1.1.1.13 mrg <br><dt><code>--with-hsa-runtime=</code><var>pathname</var><dt><code>--with-hsa-runtime-include=</code><var>pathname</var><dt><code>--with-hsa-runtime-lib=</code><var>pathname</var><dd> 1275 1.1.1.13 mrg If you configure GCC with HSA offloading but do not have the HSA 1276 1.1.1.8 mrg run-time library installed in a standard location then you can 1277 1.1.1.8 mrg explicitly specify the directory where they are installed. The 1278 1.1.1.13 mrg <samp><span class="option">--with-hsa-runtime=</span><var>hsainstalldir</var></samp> option is a 1279 1.1.1.8 mrg shorthand for 1280 1.1.1.13 mrg <samp><span class="option">--with-hsa-runtime-lib=</span><var>hsainstalldir</var><span class="option">/lib</span></samp> and 1281 1.1.1.13 mrg <samp><span class="option">--with-hsa-runtime-include=</span><var>hsainstalldir</var><span class="option">/include</span></samp>. 1282 1.1.1.7 mrg </dl> 1283 1.1.1.5 mrg 1284 1.1.1.13 mrg <h4 class="subheading"><a name="TOC3"></a>Cross-Compiler-Specific Options</h4> 1285 1.1.1.13 mrg 1286 1.1 mrg <p>The following options only apply to building cross compilers. 1287 1.1.1.13 mrg 1288 1.1.1.13 mrg <dl> 1289 1.1.1.13 mrg <dt><code>--with-sysroot</code><dt><code>--with-sysroot=</code><var>dir</var><dd>Tells GCC to consider <var>dir</var> as the root of a tree that contains 1290 1.1.1.13 mrg (a subset of) the root filesystem of the target operating system. 1291 1.1 mrg Target system headers, libraries and run-time object files will be 1292 1.1.1.3 skrll searched for in there. More specifically, this acts as if 1293 1.1.1.13 mrg <samp><span class="option">--sysroot=</span><var>dir</var></samp> was added to the default options of the built 1294 1.1 mrg compiler. The specified directory is not copied into the 1295 1.1.1.13 mrg install tree, unlike the options <samp><span class="option">--with-headers</span></samp> and 1296 1.1.1.13 mrg <samp><span class="option">--with-libs</span></samp> that this option obsoletes. The default value, 1297 1.1.1.13 mrg in case <samp><span class="option">--with-sysroot</span></samp> is not given an argument, is 1298 1.1.1.13 mrg <samp><span class="option">${gcc_tooldir}/sys-root</span></samp>. If the specified directory is a 1299 1.1.1.13 mrg subdirectory of <samp><span class="option">${exec_prefix}</span></samp>, then it will be found relative to 1300 1.1 mrg the GCC binaries if the installation tree is moved. 1301 1.1.1.13 mrg 1302 1.1.1.13 mrg <p>This option affects the system root for the compiler used to build 1303 1.1 mrg target libraries (which runs on the build system) and the compiler newly 1304 1.1 mrg installed with <code>make install</code>; it does not affect the compiler which is 1305 1.1 mrg used to build GCC itself. 1306 1.1.1.13 mrg 1307 1.1.1.13 mrg <p>If you specify the <samp><span class="option">--with-native-system-header-dir=</span><var>dirname</var></samp> 1308 1.1.1.3 skrll option then the compiler will search that directory within <var>dirname</var> for 1309 1.1.1.13 mrg native system headers rather than the default <samp><span class="file">/usr/include</span></samp>. 1310 1.1.1.13 mrg 1311 1.1.1.13 mrg <br><dt><code>--with-build-sysroot</code><dt><code>--with-build-sysroot=</code><var>dir</var><dd>Tells GCC to consider <var>dir</var> as the system root (see 1312 1.1.1.13 mrg <samp><span class="option">--with-sysroot</span></samp>) while building target libraries, instead of 1313 1.1.1.13 mrg the directory specified with <samp><span class="option">--with-sysroot</span></samp>. This option is 1314 1.1.1.13 mrg only useful when you are already using <samp><span class="option">--with-sysroot</span></samp>. You 1315 1.1.1.13 mrg can use <samp><span class="option">--with-build-sysroot</span></samp> when you are configuring with 1316 1.1.1.13 mrg <samp><span class="option">--prefix</span></samp> set to a directory that is different from the one in 1317 1.1 mrg which you are installing GCC and your target libraries. 1318 1.1.1.13 mrg 1319 1.1.1.13 mrg <p>This option affects the system root for the compiler used to build 1320 1.1 mrg target libraries (which runs on the build system); it does not affect 1321 1.1 mrg the compiler which is used to build GCC itself. 1322 1.1.1.13 mrg 1323 1.1.1.13 mrg <p>If you specify the <samp><span class="option">--with-native-system-header-dir=</span><var>dirname</var></samp> 1324 1.1.1.3 skrll option then the compiler will search that directory within <var>dirname</var> for 1325 1.1.1.13 mrg native system headers rather than the default <samp><span class="file">/usr/include</span></samp>. 1326 1.1.1.13 mrg 1327 1.1.1.13 mrg <br><dt><code>--with-headers</code><dt><code>--with-headers=</code><var>dir</var><dd>Deprecated in favor of <samp><span class="option">--with-sysroot</span></samp>. 1328 1.1.1.13 mrg Specifies that target headers are available when building a cross compiler. 1329 1.1 mrg The <var>dir</var> argument specifies a directory which has the target include 1330 1.1.1.13 mrg files. These include files will be copied into the <samp><span class="file">gcc</span></samp> install 1331 1.1.1.13 mrg directory. <em>This option with the </em><var>dir</var><em> argument is required</em> when 1332 1.1.1.13 mrg building a cross compiler, if <samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/sys-include</span></samp> 1333 1.1.1.13 mrg doesn't pre-exist. If <samp><var>prefix</var><span class="file">/</span><var>target</var><span class="file">/sys-include</span></samp> does 1334 1.1.1.13 mrg pre-exist, the <var>dir</var> argument may be omitted. <samp><span class="command">fixincludes</span></samp> 1335 1.1 mrg will be run on these files to make them compatible with GCC. 1336 1.1.1.13 mrg 1337 1.1.1.13 mrg <br><dt><code>--without-headers</code><dd>Tells GCC not use any target headers from a libc when building a cross 1338 1.1 mrg compiler. When crossing to GNU/Linux, you need the headers so GCC 1339 1.1 mrg can build the exception handling for libgcc. 1340 1.1.1.13 mrg 1341 1.1.1.13 mrg <br><dt><code>--with-libs</code><dt><code>--with-libs="</code><var>dir1</var> <var>dir2</var><code> ... </code><var>dirN</var><code>"</code><dd>Deprecated in favor of <samp><span class="option">--with-sysroot</span></samp>. 1342 1.1 mrg Specifies a list of directories which contain the target runtime 1343 1.1.1.13 mrg libraries. These libraries will be copied into the <samp><span class="file">gcc</span></samp> install 1344 1.1 mrg directory. If the directory list is omitted, this option has no 1345 1.1 mrg effect. 1346 1.1.1.13 mrg 1347 1.1.1.13 mrg <br><dt><code>--with-newlib</code><dd>Specifies that ‘<samp><span class="samp">newlib</span></samp>’ is 1348 1.1 mrg being used as the target C library. This causes <code>__eprintf</code> to be 1349 1.1.1.13 mrg omitted from <samp><span class="file">libgcc.a</span></samp> on the assumption that it will be provided by 1350 1.1.1.13 mrg ‘<samp><span class="samp">newlib</span></samp>’. 1351 1.1.1.13 mrg 1352 1.1.1.13 mrg <br><dt><code>--with-avrlibc</code><dd>Specifies that ‘<samp><span class="samp">AVR-Libc</span></samp>’ is 1353 1.1.1.3 skrll being used as the target C library. This causes float support 1354 1.1.1.13 mrg functions like <code>__addsf3</code> to be omitted from <samp><span class="file">libgcc.a</span></samp> on 1355 1.1.1.13 mrg the assumption that it will be provided by <samp><span class="file">libm.a</span></samp>. For more 1356 1.1.1.13 mrg technical details, cf. <a href="http://gcc.gnu.org/PR54461">PR54461</a>. 1357 1.1.1.3 skrll This option is only supported for the AVR target. It is not supported for 1358 1.1.1.3 skrll RTEMS configurations, which currently use newlib. The option is 1359 1.1.1.3 skrll supported since version 4.7.2 and is the default in 4.8.0 and newer. 1360 1.1.1.13 mrg 1361 1.1.1.13 mrg <br><dt><code>--with-nds32-lib=</code><var>library</var><dd>Specifies that <var>library</var> setting is used for building <samp><span class="file">libgcc.a</span></samp>. 1362 1.1.1.13 mrg Currently, the valid <var>library</var> is ‘<samp><span class="samp">newlib</span></samp>’ or ‘<samp><span class="samp">mculib</span></samp>’. 1363 1.1.1.6 mrg This option is only supported for the NDS32 target. 1364 1.1.1.13 mrg 1365 1.1.1.13 mrg <br><dt><code>--with-build-time-tools=</code><var>dir</var><dd>Specifies where to find the set of target tools (assembler, linker, etc.) 1366 1.1 mrg that will be used while building GCC itself. This option can be useful 1367 1.1 mrg if the directory layouts are different between the system you are building 1368 1.1 mrg GCC on, and the system where you will deploy it. 1369 1.1.1.13 mrg 1370 1.1.1.13 mrg <p>For example, on an ‘<samp><span class="samp">ia64-hp-hpux</span></samp>’ system, you may have the GNU 1371 1.1.1.13 mrg assembler and linker in <samp><span class="file">/usr/bin</span></samp>, and the native tools in a 1372 1.1 mrg different path, and build a toolchain that expects to find the 1373 1.1.1.13 mrg native tools in <samp><span class="file">/usr/bin</span></samp>. 1374 1.1.1.13 mrg 1375 1.1.1.13 mrg <p>When you use this option, you should ensure that <var>dir</var> includes 1376 1.1.1.13 mrg <samp><span class="command">ar</span></samp>, <samp><span class="command">as</span></samp>, <samp><span class="command">ld</span></samp>, <samp><span class="command">nm</span></samp>, 1377 1.1.1.13 mrg <samp><span class="command">ranlib</span></samp> and <samp><span class="command">strip</span></samp> if necessary, and possibly 1378 1.1.1.13 mrg <samp><span class="command">objdump</span></samp>. Otherwise, GCC may use an inconsistent set of 1379 1.1.1.13 mrg tools. 1380 1.1.1.7 mrg </dl> 1381 1.1.1.7 mrg 1382 1.1.1.13 mrg <h5 class="subsubheading"><a name="TOC4"></a>Overriding <samp><span class="command">configure</span></samp> test results</h5> 1383 1.1.1.5 mrg 1384 1.1.1.7 mrg <p>Sometimes, it might be necessary to override the result of some 1385 1.1.1.13 mrg <samp><span class="command">configure</span></samp> test, for example in order to ease porting to a new 1386 1.1.1.13 mrg system or work around a bug in a test. The toplevel <samp><span class="command">configure</span></samp> 1387 1.1.1.7 mrg script provides three variables for this: 1388 1.1.1.13 mrg 1389 1.1.1.13 mrg <dl> 1390 1.1.1.13 mrg <dt><code>build_configargs</code><dd><a name="index-g_t_0040code_007bbuild_005fconfigargs_007d-3"></a>The contents of this variable is passed to all build <samp><span class="command">configure</span></samp> 1391 1.1.1.7 mrg scripts. 1392 1.1.1.13 mrg 1393 1.1.1.13 mrg <br><dt><code>host_configargs</code><dd><a name="index-g_t_0040code_007bhost_005fconfigargs_007d-4"></a>The contents of this variable is passed to all host <samp><span class="command">configure</span></samp> 1394 1.1.1.7 mrg scripts. 1395 1.1.1.13 mrg 1396 1.1.1.13 mrg <br><dt><code>target_configargs</code><dd><a name="index-g_t_0040code_007btarget_005fconfigargs_007d-5"></a>The contents of this variable is passed to all target <samp><span class="command">configure</span></samp> 1397 1.1.1.7 mrg scripts. 1398 1.1 mrg 1399 1.1.1.13 mrg </dl> 1400 1.1.1.13 mrg 1401 1.1.1.13 mrg <p>In order to avoid shell and <samp><span class="command">make</span></samp> quoting issues for complex 1402 1.1.1.13 mrg overrides, you can pass a setting for <samp><span class="env">CONFIG_SITE</span></samp> and set 1403 1.1.1.7 mrg variables in the site file. 1404 1.1.1.13 mrg 1405 1.1.1.13 mrg <h4 class="subheading"><a name="TOC5"></a>Objective-C-Specific Options</h4> 1406 1.1.1.9 mrg 1407 1.1.1.10 mrg <p>The following options apply to the build of the Objective-C runtime library. 1408 1.1.1.13 mrg 1409 1.1.1.13 mrg <dl> 1410 1.1.1.13 mrg <dt><code>--enable-objc-gc</code><dd>Specify that an additional variant of the GNU Objective-C runtime library 1411 1.1.1.10 mrg is built, using an external build of the Boehm-Demers-Weiser garbage 1412 1.1.1.10 mrg collector (<a href="http://www.hboehm.info/gc/">http://www.hboehm.info/gc/</a>). This library needs to be 1413 1.1.1.10 mrg available for each multilib variant, unless configured with 1414 1.1.1.13 mrg <samp><span class="option">--enable-objc-gc=‘</span><samp><span class="samp">auto</span></samp><span class="option">’</span></samp> in which case the build of the 1415 1.1.1.10 mrg additional runtime library is skipped when not available and the build 1416 1.1.1.10 mrg continues. 1417 1.1.1.13 mrg 1418 1.1.1.13 mrg <br><dt><code>--with-target-bdw-gc=</code><var>list</var><dt><code>--with-target-bdw-gc-include=</code><var>list</var><dt><code>--with-target-bdw-gc-lib=</code><var>list</var><dd>Specify search directories for the garbage collector header files and 1419 1.1.1.10 mrg libraries. <var>list</var> is a comma separated list of key value pairs of the 1420 1.1.1.13 mrg form ‘<samp><var>multilibdir</var><span class="samp">=</span><var>path</var></samp>’, where the default multilib key 1421 1.1.1.13 mrg is named as ‘<samp><span class="samp">.</span></samp>’ (dot), or is omitted (e.g. 1422 1.1.1.13 mrg ‘<samp><span class="samp">--with-target-bdw-gc=/opt/bdw-gc,32=/opt-bdw-gc32</span></samp>’). 1423 1.1.1.13 mrg 1424 1.1.1.13 mrg <p>The options <samp><span class="option">--with-target-bdw-gc-include</span></samp> and 1425 1.1.1.13 mrg <samp><span class="option">--with-target-bdw-gc-lib</span></samp> must always be specified together 1426 1.1.1.10 mrg for each multilib variant and they take precedence over 1427 1.1.1.13 mrg <samp><span class="option">--with-target-bdw-gc</span></samp>. If <samp><span class="option">--with-target-bdw-gc-include</span></samp> 1428 1.1.1.10 mrg is missing values for a multilib, then the value for the default 1429 1.1.1.13 mrg multilib is used (e.g. ‘<samp><span class="samp">--with-target-bdw-gc-include=/opt/bdw-gc/include</span></samp>’ 1430 1.1.1.13 mrg ‘<samp><span class="samp">--with-target-bdw-gc-lib=/opt/bdw-gc/lib64,32=/opt-bdw-gc/lib32</span></samp>’). 1431 1.1.1.10 mrg If none of these options are specified, the library is assumed in 1432 1.1.1.13 mrg default locations. 1433 1.1.1.9 mrg </dl> 1434 1.1.1.3 skrll 1435 1.1.1.13 mrg <p><hr /> 1436 1.1.1.9 mrg <p><a href="./index.html">Return to the GCC Installation page</a> 1437 1.1 mrg 1438 1.1.1.13 mrg <!-- ***Building**************************************************************** --> 1439 1.1.1.13 mrg <!-- ***Testing***************************************************************** --> 1440 1.1.1.13 mrg <!-- ***Final install*********************************************************** --> 1441 1.1.1.13 mrg <!-- ***Binaries**************************************************************** --> 1442 1.1.1.13 mrg <!-- ***Specific**************************************************************** --> 1443 1.1.1.13 mrg <!-- ***Old documentation****************************************************** --> 1444 1.1.1.13 mrg <!-- ***GFDL******************************************************************** --> 1445 1.1.1.13 mrg <!-- *************************************************************************** --> 1446 1.1.1.13 mrg <!-- Part 6 The End of the Document --> 1447 1.1.1.13 mrg </body></html> 1448 1.1 mrg 1449
Indexes created Thu Jul 16 00:26:27 UTC 2026