configure.html revision 1.13
1 1.10 mrg <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2 1.10 mrg <html> 3 1.13 mrg <!-- Copyright (C) 1988-2020 Free Software Foundation, Inc. 4 1.1 mrg 5 1.10 mrg Permission is granted to copy, distribute and/or modify this document 6 1.3 skrll under the terms of the GNU Free Documentation License, Version 1.3 or 7 1.1 mrg any later version published by the Free Software Foundation; with no 8 1.1 mrg Invariant Sections, the Front-Cover texts being (a) (see below), and 9 1.1 mrg with the Back-Cover Texts being (b) (see below). A copy of the 10 1.10 mrg license is included in the section entitled "GNU 11 1.10 mrg Free Documentation License". 12 1.1 mrg 13 1.1 mrg (a) The FSF's Front-Cover Text is: 14 1.1 mrg 15 1.10 mrg A GNU Manual 16 1.1 mrg 17 1.1 mrg (b) The FSF's Back-Cover Text is: 18 1.1 mrg 19 1.10 mrg You have freedom to copy and modify this GNU Manual, like GNU 20 1.1 mrg software. Copies published by the Free Software Foundation raise 21 1.10 mrg funds for GNU development. --> 22 1.10 mrg <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ --> 23 1.10 mrg <head> 24 1.10 mrg <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 25 1.13 mrg <title>Installing GCC: Configuration</title> 26 1.10 mrg 27 1.13 mrg <meta name="description" content="Installing GCC: Configuration"> 28 1.13 mrg <meta name="keywords" content="Installing GCC: Configuration"> 29 1.10 mrg <meta name="resource-type" content="document"> 30 1.10 mrg <meta name="distribution" content="global"> 31 1.10 mrg <meta name="Generator" content="makeinfo"> 32 1.10 mrg <style type="text/css"> 33 1.10 mrg <!-- 34 1.10 mrg a.summary-letter {text-decoration: none} 35 1.10 mrg blockquote.indentedblock {margin-right: 0em} 36 1.10 mrg blockquote.smallindentedblock {margin-right: 0em; font-size: smaller} 37 1.10 mrg blockquote.smallquotation {font-size: smaller} 38 1.10 mrg div.display {margin-left: 3.2em} 39 1.10 mrg div.example {margin-left: 3.2em} 40 1.10 mrg div.lisp {margin-left: 3.2em} 41 1.10 mrg div.smalldisplay {margin-left: 3.2em} 42 1.10 mrg div.smallexample {margin-left: 3.2em} 43 1.10 mrg div.smalllisp {margin-left: 3.2em} 44 1.10 mrg kbd {font-style: oblique} 45 1.10 mrg pre.display {font-family: inherit} 46 1.10 mrg pre.format {font-family: inherit} 47 1.10 mrg pre.menu-comment {font-family: serif} 48 1.10 mrg pre.menu-preformatted {font-family: serif} 49 1.10 mrg pre.smalldisplay {font-family: inherit; font-size: smaller} 50 1.10 mrg pre.smallexample {font-size: smaller} 51 1.10 mrg pre.smallformat {font-family: inherit; font-size: smaller} 52 1.10 mrg pre.smalllisp {font-size: smaller} 53 1.10 mrg span.nolinebreak {white-space: nowrap} 54 1.10 mrg span.roman {font-family: initial; font-weight: normal} 55 1.10 mrg span.sansserif {font-family: sans-serif; font-weight: normal} 56 1.10 mrg ul.no-bullet {list-style: none} 57 1.10 mrg --> 58 1.10 mrg </style> 59 1.10 mrg 60 1.10 mrg 61 1.1 mrg </head> 62 1.10 mrg 63 1.10 mrg <body lang="en"> 64 1.13 mrg <h1 class="settitle" align="center">Installing GCC: Configuration</h1> 65 1.10 mrg 66 1.10 mrg 67 1.10 mrg 68 1.10 mrg 69 1.10 mrg 70 1.10 mrg 71 1.10 mrg 72 1.10 mrg 73 1.10 mrg 74 1.10 mrg 75 1.10 mrg 76 1.10 mrg 77 1.10 mrg 78 1.10 mrg 79 1.10 mrg 80 1.10 mrg 81 1.10 mrg 82 1.10 mrg 83 1.10 mrg 84 1.10 mrg <a name="index-Configuration"></a> 85 1.10 mrg <a name="index-Installing-GCC_003a-Configuration"></a> 86 1.10 mrg 87 1.10 mrg <p>Like most GNU software, GCC must be configured before it can be built. 88 1.9 mrg This document describes the recommended configuration procedure 89 1.9 mrg for both native and cross targets. 90 1.10 mrg </p> 91 1.10 mrg <p>We use <var>srcdir</var> to refer to the toplevel source directory for 92 1.9 mrg GCC; we use <var>objdir</var> to refer to the toplevel build/object directory. 93 1.10 mrg </p> 94 1.11 mrg <p>If you obtained the sources by cloning the repository, <var>srcdir</var> 95 1.11 mrg must refer to the top <samp>gcc</samp> directory, the one where the 96 1.11 mrg <samp>MAINTAINERS</samp> file can be found, and not its <samp>gcc</samp> 97 1.11 mrg subdirectory, otherwise the build will fail. 98 1.10 mrg </p> 99 1.10 mrg <p>If either <var>srcdir</var> or <var>objdir</var> is located on an automounted NFS 100 1.10 mrg file system, the shell’s built-in <code>pwd</code> command will return 101 1.1 mrg temporary pathnames. Using these can lead to various sorts of build 102 1.10 mrg problems. To avoid this issue, set the <code>PWDCMD</code> environment 103 1.10 mrg variable to an automounter-aware <code>pwd</code> command, e.g., 104 1.10 mrg <code>pawd</code> or ‘<samp>amq -w</samp>’, during the configuration and build 105 1.1 mrg phases. 106 1.10 mrg </p> 107 1.10 mrg <p>First, we <strong>highly</strong> recommend that GCC be built into a 108 1.1 mrg separate directory from the sources which does <strong>not</strong> reside 109 1.1 mrg within the source tree. This is how we generally build GCC; building 110 1.10 mrg where <var>srcdir</var> == <var>objdir</var> should still work, but doesn’t 111 1.1 mrg get extensive testing; building where <var>objdir</var> is a subdirectory 112 1.1 mrg of <var>srcdir</var> is unsupported. 113 1.10 mrg </p> 114 1.10 mrg <p>If you have previously built GCC in the same directory for a 115 1.10 mrg different target machine, do ‘<samp>make distclean</samp>’ to delete all files 116 1.10 mrg that might be invalid. One of the files this deletes is <samp>Makefile</samp>; 117 1.10 mrg if ‘<samp>make distclean</samp>’ complains that <samp>Makefile</samp> does not exist 118 1.10 mrg or issues a message like “don’t know how to make distclean” it probably 119 1.1 mrg means that the directory is already suitably clean. However, with the 120 1.1 mrg recommended method of building in a separate <var>objdir</var>, you should 121 1.1 mrg simply use a different <var>objdir</var> for each target. 122 1.10 mrg </p> 123 1.10 mrg <p>Second, when configuring a native system, either <code>cc</code> or 124 1.10 mrg <code>gcc</code> must be in your path or you must set <code>CC</code> in 125 1.1 mrg your environment before running configure. Otherwise the configuration 126 1.1 mrg scripts may fail. 127 1.10 mrg </p> 128 1.1 mrg 129 1.10 mrg <p>To configure GCC: 130 1.10 mrg </p> 131 1.10 mrg <div class="smallexample"> 132 1.10 mrg <pre class="smallexample">% mkdir <var>objdir</var> 133 1.10 mrg % cd <var>objdir</var> 134 1.10 mrg % <var>srcdir</var>/configure [<var>options</var>] [<var>target</var>] 135 1.10 mrg </pre></div> 136 1.1 mrg 137 1.10 mrg <a name="Distributor-options"></a> 138 1.10 mrg <h3 class="heading">Distributor options</h3> 139 1.1 mrg 140 1.1 mrg <p>If you will be distributing binary versions of GCC, with modifications 141 1.1 mrg to the source code, you should use the options described in this 142 1.1 mrg section to make clear that your version contains modifications. 143 1.10 mrg </p> 144 1.10 mrg <dl compact="compact"> 145 1.10 mrg <dt><code>--with-pkgversion=<var>version</var></code></dt> 146 1.10 mrg <dd><p>Specify a string that identifies your package. You may wish 147 1.1 mrg to include a build number or build date. This version string will be 148 1.10 mrg included in the output of <code>gcc --version</code>. This suffix does 149 1.10 mrg not replace the default version string, only the ‘<samp>GCC</samp>’ part. 150 1.10 mrg </p> 151 1.10 mrg <p>The default value is ‘<samp>GCC</samp>’. 152 1.10 mrg </p> 153 1.10 mrg </dd> 154 1.10 mrg <dt><code>--with-bugurl=<var>url</var></code></dt> 155 1.10 mrg <dd><p>Specify the URL that users should visit if they wish to report a bug. 156 1.1 mrg You are of course welcome to forward bugs reported to you to the FSF, 157 1.1 mrg if you determine that they are not bugs in your modifications. 158 1.10 mrg </p> 159 1.10 mrg <p>The default value refers to the FSF’s GCC bug tracker. 160 1.10 mrg </p> 161 1.10 mrg </dd> 162 1.13 mrg <dt><code>--with-documentation-root-url=<var>url</var></code></dt> 163 1.13 mrg <dd><p>Specify the URL root that contains GCC option documentation. The <var>url</var> 164 1.13 mrg should end with a <code>/</code> character. 165 1.13 mrg </p> 166 1.13 mrg <p>The default value is <a href="https://gcc.gnu.org/onlinedocs/">https://gcc.gnu.org/onlinedocs/</a>. 167 1.13 mrg </p> 168 1.13 mrg </dd> 169 1.13 mrg <dt><code>--with-changes-root-url=<var>url</var></code></dt> 170 1.13 mrg <dd><p>Specify the URL root that contains information about changes in GCC 171 1.13 mrg releases like <code>gcc-<var>version</var>/changes.html</code>. 172 1.13 mrg The <var>url</var> should end with a <code>/</code> character. 173 1.13 mrg </p> 174 1.13 mrg <p>The default value is <a href="https://gcc.gnu.org/">https://gcc.gnu.org/</a>. 175 1.13 mrg </p> 176 1.13 mrg </dd> 177 1.10 mrg </dl> 178 1.1 mrg 179 1.10 mrg <a name="Target-specification"></a> 180 1.10 mrg <h3 class="heading">Target specification</h3> 181 1.10 mrg <ul> 182 1.10 mrg <li> GCC has code to correctly determine the correct value for <var>target</var> 183 1.1 mrg for nearly all native systems. Therefore, we highly recommend you do 184 1.1 mrg not provide a configure target when configuring a native compiler. 185 1.1 mrg 186 1.10 mrg </li><li> <var>target</var> must be specified as <samp>--target=<var>target</var></samp> 187 1.1 mrg when configuring a cross compiler; examples of valid targets would be 188 1.1 mrg m68k-elf, sh-elf, etc. 189 1.1 mrg 190 1.10 mrg </li><li> Specifying just <var>target</var> instead of <samp>--target=<var>target</var></samp> 191 1.10 mrg implies that the host defaults to <var>target</var>. 192 1.10 mrg </li></ul> 193 1.10 mrg 194 1.1 mrg 195 1.10 mrg <a name="Options-specification"></a> 196 1.10 mrg <h3 class="heading">Options specification</h3> 197 1.1 mrg 198 1.1 mrg <p>Use <var>options</var> to override several configure time options for 199 1.10 mrg GCC. A list of supported <var>options</var> follows; ‘<samp>configure 200 1.10 mrg --help</samp>’ may list other options, but those not listed below may not 201 1.1 mrg work and should not normally be used. 202 1.10 mrg </p> 203 1.10 mrg <p>Note that each <samp>--enable</samp> option has a corresponding 204 1.10 mrg <samp>--disable</samp> option and that each <samp>--with</samp> option has a 205 1.10 mrg corresponding <samp>--without</samp> option. 206 1.10 mrg </p> 207 1.10 mrg <dl compact="compact"> 208 1.10 mrg <dt><code>--prefix=<var>dirname</var></code></dt> 209 1.10 mrg <dd><p>Specify the toplevel installation 210 1.1 mrg directory. This is the recommended way to install the tools into a directory 211 1.1 mrg other than the default. The toplevel installation directory defaults to 212 1.10 mrg <samp>/usr/local</samp>. 213 1.10 mrg </p> 214 1.10 mrg <p>We <strong>highly</strong> recommend against <var>dirname</var> being the same or a 215 1.1 mrg subdirectory of <var>objdir</var> or vice versa. If specifying a directory 216 1.10 mrg beneath a user’s home directory tree, some shells will not expand 217 1.10 mrg <var>dirname</var> correctly if it contains the ‘<samp>~</samp>’ metacharacter; use 218 1.10 mrg <code>$HOME</code> instead. 219 1.10 mrg </p> 220 1.10 mrg <p>The following standard <code>autoconf</code> options are supported. Normally you 221 1.1 mrg should not need to use these options. 222 1.10 mrg </p><dl compact="compact"> 223 1.10 mrg <dt><code>--exec-prefix=<var>dirname</var></code></dt> 224 1.10 mrg <dd><p>Specify the toplevel installation directory for architecture-dependent 225 1.1 mrg files. The default is <samp><var>prefix</var></samp>. 226 1.10 mrg </p> 227 1.10 mrg </dd> 228 1.10 mrg <dt><code>--bindir=<var>dirname</var></code></dt> 229 1.10 mrg <dd><p>Specify the installation directory for the executables called by users 230 1.10 mrg (such as <code>gcc</code> and <code>g++</code>). The default is 231 1.10 mrg <samp><var>exec-prefix</var>/bin</samp>. 232 1.10 mrg </p> 233 1.10 mrg </dd> 234 1.10 mrg <dt><code>--libdir=<var>dirname</var></code></dt> 235 1.10 mrg <dd><p>Specify the installation directory for object code libraries and 236 1.10 mrg internal data files of GCC. The default is <samp><var>exec-prefix</var>/lib</samp>. 237 1.10 mrg </p> 238 1.10 mrg </dd> 239 1.10 mrg <dt><code>--libexecdir=<var>dirname</var></code></dt> 240 1.10 mrg <dd><p>Specify the installation directory for internal executables of GCC. 241 1.10 mrg The default is <samp><var>exec-prefix</var>/libexec</samp>. 242 1.10 mrg </p> 243 1.10 mrg </dd> 244 1.10 mrg <dt><code>--with-slibdir=<var>dirname</var></code></dt> 245 1.10 mrg <dd><p>Specify the installation directory for the shared libgcc library. The 246 1.1 mrg default is <samp><var>libdir</var></samp>. 247 1.10 mrg </p> 248 1.10 mrg </dd> 249 1.10 mrg <dt><code>--datarootdir=<var>dirname</var></code></dt> 250 1.10 mrg <dd><p>Specify the root of the directory tree for read-only architecture-independent 251 1.10 mrg data files referenced by GCC. The default is <samp><var>prefix</var>/share</samp>. 252 1.10 mrg </p> 253 1.10 mrg </dd> 254 1.10 mrg <dt><code>--infodir=<var>dirname</var></code></dt> 255 1.10 mrg <dd><p>Specify the installation directory for documentation in info format. 256 1.10 mrg The default is <samp><var>datarootdir</var>/info</samp>. 257 1.10 mrg </p> 258 1.10 mrg </dd> 259 1.10 mrg <dt><code>--datadir=<var>dirname</var></code></dt> 260 1.10 mrg <dd><p>Specify the installation directory for some architecture-independent 261 1.1 mrg data files referenced by GCC. The default is <samp><var>datarootdir</var></samp>. 262 1.10 mrg </p> 263 1.10 mrg </dd> 264 1.10 mrg <dt><code>--docdir=<var>dirname</var></code></dt> 265 1.10 mrg <dd><p>Specify the installation directory for documentation files (other 266 1.10 mrg than Info) for GCC. The default is <samp><var>datarootdir</var>/doc</samp>. 267 1.10 mrg </p> 268 1.10 mrg </dd> 269 1.10 mrg <dt><code>--htmldir=<var>dirname</var></code></dt> 270 1.10 mrg <dd><p>Specify the installation directory for HTML documentation files. 271 1.1 mrg The default is <samp><var>docdir</var></samp>. 272 1.10 mrg </p> 273 1.10 mrg </dd> 274 1.10 mrg <dt><code>--pdfdir=<var>dirname</var></code></dt> 275 1.10 mrg <dd><p>Specify the installation directory for PDF documentation files. 276 1.1 mrg The default is <samp><var>docdir</var></samp>. 277 1.10 mrg </p> 278 1.10 mrg </dd> 279 1.10 mrg <dt><code>--mandir=<var>dirname</var></code></dt> 280 1.10 mrg <dd><p>Specify the installation directory for manual pages. The default is 281 1.10 mrg <samp><var>datarootdir</var>/man</samp>. (Note that the manual pages are only extracts 282 1.1 mrg from the full GCC manuals, which are provided in Texinfo format. The manpages 283 1.1 mrg are derived by an automatic conversion process from parts of the full 284 1.1 mrg manual.) 285 1.10 mrg </p> 286 1.10 mrg </dd> 287 1.10 mrg <dt><code>--with-gxx-include-dir=<var>dirname</var></code></dt> 288 1.10 mrg <dd><p>Specify 289 1.1 mrg the installation directory for G++ header files. The default depends 290 1.1 mrg on other configuration options, and differs between cross and native 291 1.1 mrg configurations. 292 1.10 mrg </p> 293 1.10 mrg </dd> 294 1.10 mrg <dt><code>--with-specs=<var>specs</var></code></dt> 295 1.10 mrg <dd><p>Specify additional command line driver SPECS. 296 1.3 skrll This can be useful if you need to turn on a non-standard feature by 297 1.10 mrg default without modifying the compiler’s source code, for instance 298 1.10 mrg <samp>--with-specs=%{!fcommon:%{!fno-common:-fno-common}}</samp>. 299 1.3 skrll See “Spec Files” in the main manual 300 1.10 mrg </p> 301 1.10 mrg </dd> 302 1.10 mrg </dl> 303 1.3 skrll 304 1.10 mrg </dd> 305 1.10 mrg <dt><code>--program-prefix=<var>prefix</var></code></dt> 306 1.10 mrg <dd><p>GCC supports some transformations of the names of its programs when 307 1.1 mrg installing them. This option prepends <var>prefix</var> to the names of 308 1.1 mrg programs to install in <var>bindir</var> (see above). For example, specifying 309 1.10 mrg <samp>--program-prefix=foo-</samp> would result in ‘<samp>gcc</samp>’ 310 1.10 mrg being installed as <samp>/usr/local/bin/foo-gcc</samp>. 311 1.10 mrg </p> 312 1.10 mrg </dd> 313 1.10 mrg <dt><code>--program-suffix=<var>suffix</var></code></dt> 314 1.10 mrg <dd><p>Appends <var>suffix</var> to the names of programs to install in <var>bindir</var> 315 1.10 mrg (see above). For example, specifying <samp>--program-suffix=-3.1</samp> 316 1.10 mrg would result in ‘<samp>gcc</samp>’ being installed as 317 1.10 mrg <samp>/usr/local/bin/gcc-3.1</samp>. 318 1.10 mrg </p> 319 1.10 mrg </dd> 320 1.10 mrg <dt><code>--program-transform-name=<var>pattern</var></code></dt> 321 1.10 mrg <dd><p>Applies the ‘<samp>sed</samp>’ script <var>pattern</var> to be applied to the names 322 1.1 mrg of programs to install in <var>bindir</var> (see above). <var>pattern</var> has to 323 1.10 mrg consist of one or more basic ‘<samp>sed</samp>’ editing commands, separated by 324 1.10 mrg semicolons. For example, if you want the ‘<samp>gcc</samp>’ program name to be 325 1.10 mrg transformed to the installed program <samp>/usr/local/bin/myowngcc</samp> and 326 1.10 mrg the ‘<samp>g++</samp>’ program name to be transformed to 327 1.10 mrg <samp>/usr/local/bin/gspecial++</samp> without changing other program names, 328 1.1 mrg you could use the pattern 329 1.10 mrg <samp>--program-transform-name='s/^gcc$/myowngcc/; s/^g++$/gspecial++/'</samp> 330 1.1 mrg to achieve this effect. 331 1.10 mrg </p> 332 1.10 mrg <p>All three options can be combined and used together, resulting in more 333 1.1 mrg complex conversion patterns. As a basic rule, <var>prefix</var> (and 334 1.1 mrg <var>suffix</var>) are prepended (appended) before further transformations 335 1.1 mrg can happen with a special transformation script <var>pattern</var>. 336 1.10 mrg </p> 337 1.10 mrg <p>As currently implemented, this option only takes effect for native 338 1.10 mrg builds; cross compiler binaries’ names are not transformed even when a 339 1.1 mrg transformation is explicitly asked for by one of these options. 340 1.10 mrg </p> 341 1.10 mrg <p>For native builds, some of the installed programs are also installed 342 1.1 mrg with the target alias in front of their name, as in 343 1.10 mrg ‘<samp>i686-pc-linux-gnu-gcc</samp>’. All of the above transformations happen 344 1.1 mrg before the target alias is prepended to the name—so, specifying 345 1.10 mrg <samp>--program-prefix=foo-</samp> and <samp>program-suffix=-3.1</samp>, the 346 1.1 mrg resulting binary would be installed as 347 1.10 mrg <samp>/usr/local/bin/i686-pc-linux-gnu-foo-gcc-3.1</samp>. 348 1.10 mrg </p> 349 1.10 mrg <p>As a last shortcoming, none of the installed Ada programs are 350 1.1 mrg transformed yet, which will be fixed in some time. 351 1.10 mrg </p> 352 1.10 mrg </dd> 353 1.10 mrg <dt><code>--with-local-prefix=<var>dirname</var></code></dt> 354 1.10 mrg <dd><p>Specify the 355 1.1 mrg installation directory for local include files. The default is 356 1.10 mrg <samp>/usr/local</samp>. Specify this option if you want the compiler to 357 1.10 mrg search directory <samp><var>dirname</var>/include</samp> for locally installed 358 1.10 mrg header files <em>instead</em> of <samp>/usr/local/include</samp>. 359 1.10 mrg </p> 360 1.10 mrg <p>You should specify <samp>--with-local-prefix</samp> <strong>only</strong> if your 361 1.10 mrg site has a different convention (not <samp>/usr/local</samp>) for where to put 362 1.1 mrg site-specific files. 363 1.10 mrg </p> 364 1.10 mrg <p>The default value for <samp>--with-local-prefix</samp> is <samp>/usr/local</samp> 365 1.10 mrg regardless of the value of <samp>--prefix</samp>. Specifying 366 1.10 mrg <samp>--prefix</samp> has no effect on which directory GCC searches for 367 1.1 mrg local header files. This may seem counterintuitive, but actually it is 368 1.1 mrg logical. 369 1.10 mrg </p> 370 1.10 mrg <p>The purpose of <samp>--prefix</samp> is to specify where to <em>install 371 1.10 mrg GCC</em>. The local header files in <samp>/usr/local/include</samp>—if you put 372 1.1 mrg any in that directory—are not part of GCC. They are part of other 373 1.1 mrg programs—perhaps many others. (GCC installs its own header files in 374 1.10 mrg another directory which is based on the <samp>--prefix</samp> value.) 375 1.10 mrg </p> 376 1.10 mrg <p>Both the local-prefix include directory and the GCC-prefix include 377 1.10 mrg directory are part of GCC’s “system include” directories. Although these 378 1.1 mrg two directories are not fixed, they need to be searched in the proper 379 1.1 mrg order for the correct processing of the include_next directive. The 380 1.1 mrg local-prefix include directory is searched before the GCC-prefix 381 1.1 mrg include directory. Another characteristic of system include directories 382 1.1 mrg is that pedantic warnings are turned off for headers in these directories. 383 1.10 mrg </p> 384 1.10 mrg <p>Some autoconf macros add <samp>-I <var>directory</var></samp> options to the 385 1.1 mrg compiler command line, to ensure that directories containing installed 386 1.10 mrg packages’ headers are searched. When <var>directory</var> is one of GCC’s 387 1.1 mrg system include directories, GCC will ignore the option so that system 388 1.1 mrg directories continue to be processed in the correct order. This 389 1.1 mrg may result in a search order different from what was specified but the 390 1.1 mrg directory will still be searched. 391 1.10 mrg </p> 392 1.10 mrg <p>GCC automatically searches for ordinary libraries using 393 1.10 mrg <code>GCC_EXEC_PREFIX</code>. Thus, when the same installation prefix is 394 1.1 mrg used for both GCC and packages, GCC will automatically search for 395 1.1 mrg both headers and libraries. This provides a configuration that is 396 1.1 mrg easy to use. GCC behaves in a manner similar to that when it is 397 1.10 mrg installed as a system compiler in <samp>/usr</samp>. 398 1.10 mrg </p> 399 1.10 mrg <p>Sites that need to install multiple versions of GCC may not want to 400 1.1 mrg use the above simple configuration. It is possible to use the 401 1.10 mrg <samp>--program-prefix</samp>, <samp>--program-suffix</samp> and 402 1.10 mrg <samp>--program-transform-name</samp> options to install multiple versions 403 1.1 mrg into a single directory, but it may be simpler to use different prefixes 404 1.10 mrg and the <samp>--with-local-prefix</samp> option to specify the location of the 405 1.1 mrg site-specific files for each version. It will then be necessary for 406 1.1 mrg users to specify explicitly the location of local site libraries 407 1.10 mrg (e.g., with <code>LIBRARY_PATH</code>). 408 1.10 mrg </p> 409 1.10 mrg <p>The same value can be used for both <samp>--with-local-prefix</samp> and 410 1.10 mrg <samp>--prefix</samp> provided it is not <samp>/usr</samp>. This can be used 411 1.10 mrg to avoid the default search of <samp>/usr/local/include</samp>. 412 1.10 mrg </p> 413 1.10 mrg <p><strong>Do not</strong> specify <samp>/usr</samp> as the <samp>--with-local-prefix</samp>! 414 1.10 mrg The directory you use for <samp>--with-local-prefix</samp> <strong>must not</strong> 415 1.10 mrg contain any of the system’s standard header files. If it did contain 416 1.1 mrg them, certain programs would be miscompiled (including GNU Emacs, on 417 1.1 mrg certain targets), because this would override and nullify the header 418 1.10 mrg file corrections made by the <code>fixincludes</code> script. 419 1.10 mrg </p> 420 1.10 mrg <p>Indications are that people who use this option use it based on mistaken 421 1.1 mrg ideas of what it is for. People use it as if it specified where to 422 1.1 mrg install part of GCC. Perhaps they make this assumption because 423 1.1 mrg installing GCC creates the directory. 424 1.10 mrg </p> 425 1.10 mrg </dd> 426 1.10 mrg <dt><code>--with-gcc-major-version-only</code></dt> 427 1.10 mrg <dd><p>Specifies that GCC should use only the major number rather than 428 1.9 mrg <var>major</var>.<var>minor</var>.<var>patchlevel</var> in filesystem paths. 429 1.10 mrg </p> 430 1.10 mrg </dd> 431 1.10 mrg <dt><code>--with-native-system-header-dir=<var>dirname</var></code></dt> 432 1.10 mrg <dd><p>Specifies that <var>dirname</var> is the directory that contains native system 433 1.10 mrg header files, rather than <samp>/usr/include</samp>. This option is most useful 434 1.3 skrll if you are creating a compiler that should be isolated from the system 435 1.3 skrll as much as possible. It is most commonly used with the 436 1.10 mrg <samp>--with-sysroot</samp> option and will cause GCC to search 437 1.3 skrll <var>dirname</var> inside the system root specified by that option. 438 1.10 mrg </p> 439 1.10 mrg </dd> 440 1.10 mrg <dt><code>--enable-shared[=<var>package</var>[,…]]</code></dt> 441 1.10 mrg <dd><p>Build shared versions of libraries, if shared libraries are supported on 442 1.1 mrg the target platform. Unlike GCC 2.95.x and earlier, shared libraries 443 1.1 mrg are enabled by default on all platforms that support shared libraries. 444 1.10 mrg </p> 445 1.10 mrg <p>If a list of packages is given as an argument, build shared libraries 446 1.1 mrg only for the listed packages. For other packages, only static libraries 447 1.1 mrg will be built. Package names currently recognized in the GCC tree are 448 1.10 mrg ‘<samp>libgcc</samp>’ (also known as ‘<samp>gcc</samp>’), ‘<samp>libstdc++</samp>’ (not 449 1.10 mrg ‘<samp>libstdc++-v3</samp>’), ‘<samp>libffi</samp>’, ‘<samp>zlib</samp>’, ‘<samp>boehm-gc</samp>’, 450 1.12 mrg ‘<samp>ada</samp>’, ‘<samp>libada</samp>’, ‘<samp>libgo</samp>’, ‘<samp>libobjc</samp>’, and ‘<samp>libphobos</samp>’. 451 1.10 mrg Note ‘<samp>libiberty</samp>’ does not support shared libraries at all. 452 1.10 mrg </p> 453 1.10 mrg <p>Use <samp>--disable-shared</samp> to build only static libraries. Note that 454 1.10 mrg <samp>--disable-shared</samp> does not accept a list of package names as 455 1.10 mrg argument, only <samp>--enable-shared</samp> does. 456 1.10 mrg </p> 457 1.10 mrg <p>Contrast with <samp>--enable-host-shared</samp>, which affects <em>host</em> 458 1.5 mrg code. 459 1.10 mrg </p> 460 1.10 mrg </dd> 461 1.10 mrg <dt><code>--enable-host-shared</code></dt> 462 1.10 mrg <dd><p>Specify that the <em>host</em> code should be built into position-independent 463 1.5 mrg machine code (with -fPIC), allowing it to be used within shared libraries, 464 1.5 mrg but yielding a slightly slower compiler. 465 1.10 mrg </p> 466 1.10 mrg <p>This option is required when building the libgccjit.so library. 467 1.10 mrg </p> 468 1.10 mrg <p>Contrast with <samp>--enable-shared</samp>, which affects <em>target</em> 469 1.5 mrg libraries. 470 1.10 mrg </p> 471 1.10 mrg </dd> 472 1.10 mrg <dt><code><a name="with-gnu-as"></a>--with-gnu-as</code></dt> 473 1.10 mrg <dd><p>Specify that the compiler should assume that the 474 1.1 mrg assembler it finds is the GNU assembler. However, this does not modify 475 1.1 mrg the rules to find an assembler and will result in confusion if the 476 1.1 mrg assembler found is not actually the GNU assembler. (Confusion may also 477 1.1 mrg result if the compiler finds the GNU assembler but has not been 478 1.10 mrg configured with <samp>--with-gnu-as</samp>.) If you have more than one 479 1.1 mrg assembler installed on your system, you may want to use this option in 480 1.10 mrg connection with <samp>--with-as=<var>pathname</var></samp> or 481 1.10 mrg <samp>--with-build-time-tools=<var>pathname</var></samp>. 482 1.10 mrg </p> 483 1.10 mrg <p>The following systems are the only ones where it makes a difference 484 1.1 mrg whether you use the GNU assembler. On any other system, 485 1.10 mrg <samp>--with-gnu-as</samp> has no effect. 486 1.10 mrg </p> 487 1.10 mrg <ul> 488 1.10 mrg <li> ‘<samp>hppa1.0-<var>any</var>-<var>any</var></samp>’ 489 1.10 mrg </li><li> ‘<samp>hppa1.1-<var>any</var>-<var>any</var></samp>’ 490 1.10 mrg </li><li> ‘<samp>sparc-sun-solaris2.<var>any</var></samp>’ 491 1.10 mrg </li><li> ‘<samp>sparc64-<var>any</var>-solaris2.<var>any</var></samp>’ 492 1.10 mrg </li></ul> 493 1.10 mrg 494 1.10 mrg </dd> 495 1.10 mrg <dt><code><a name="with-as"></a>--with-as=<var>pathname</var></code></dt> 496 1.10 mrg <dd><p>Specify that the compiler should use the assembler pointed to by 497 1.1 mrg <var>pathname</var>, rather than the one found by the standard rules to find 498 1.1 mrg an assembler, which are: 499 1.10 mrg </p><ul> 500 1.10 mrg <li> Unless GCC is being built with a cross compiler, check the 501 1.10 mrg <samp><var>libexec</var>/gcc/<var>target</var>/<var>version</var></samp> directory. 502 1.10 mrg <var>libexec</var> defaults to <samp><var>exec-prefix</var>/libexec</samp>; 503 1.1 mrg <var>exec-prefix</var> defaults to <var>prefix</var>, which 504 1.10 mrg defaults to <samp>/usr/local</samp> unless overridden by the 505 1.10 mrg <samp>--prefix=<var>pathname</var></samp> switch described above. <var>target</var> 506 1.10 mrg is the target system triple, such as ‘<samp>sparc-sun-solaris2.7</samp>’, and 507 1.1 mrg <var>version</var> denotes the GCC version, such as 3.0. 508 1.1 mrg 509 1.10 mrg </li><li> If the target system is the same that you are building on, check 510 1.10 mrg operating system specific directories (e.g. <samp>/usr/ccs/bin</samp> on 511 1.13 mrg Solaris 2). 512 1.1 mrg 513 1.10 mrg </li><li> Check in the <code>PATH</code> for a tool whose name is prefixed by the 514 1.1 mrg target system triple. 515 1.1 mrg 516 1.10 mrg </li><li> Check in the <code>PATH</code> for a tool whose name is not prefixed by the 517 1.1 mrg target system triple, if the host and target system triple are 518 1.1 mrg the same (in other words, we use a host tool if it can be used for 519 1.10 mrg the target as well). 520 1.10 mrg </li></ul> 521 1.1 mrg 522 1.10 mrg <p>You may want to use <samp>--with-as</samp> if no assembler 523 1.1 mrg is installed in the directories listed above, or if you have multiple 524 1.1 mrg assemblers installed and want to choose one that is not found by the 525 1.1 mrg above rules. 526 1.10 mrg </p> 527 1.10 mrg </dd> 528 1.10 mrg <dt><code><a name="with-gnu-ld"></a>--with-gnu-ld</code></dt> 529 1.10 mrg <dd><p>Same as <a href="#with-gnu-as"><samp>--with-gnu-as</samp></a> 530 1.1 mrg but for the linker. 531 1.10 mrg </p> 532 1.10 mrg </dd> 533 1.10 mrg <dt><code>--with-ld=<var>pathname</var></code></dt> 534 1.10 mrg <dd><p>Same as <a href="#with-as"><samp>--with-as</samp></a> 535 1.1 mrg but for the linker. 536 1.10 mrg </p> 537 1.10 mrg </dd> 538 1.10 mrg <dt><code>--with-stabs</code></dt> 539 1.10 mrg <dd><p>Specify that stabs debugging 540 1.1 mrg information should be used instead of whatever format the host normally 541 1.1 mrg uses. Normally GCC uses the same debug format as the host system. 542 1.10 mrg </p> 543 1.10 mrg </dd> 544 1.10 mrg <dt><code>--with-tls=<var>dialect</var></code></dt> 545 1.10 mrg <dd><p>Specify the default TLS dialect, for systems were there is a choice. 546 1.3 skrll For ARM targets, possible values for <var>dialect</var> are <code>gnu</code> or 547 1.3 skrll <code>gnu2</code>, which select between the original GNU dialect and the GNU TLS 548 1.3 skrll descriptor-based dialect. 549 1.10 mrg </p> 550 1.10 mrg </dd> 551 1.10 mrg <dt><code>--enable-multiarch</code></dt> 552 1.10 mrg <dd><p>Specify whether to enable or disable multiarch support. The default is 553 1.3 skrll to check for glibc start files in a multiarch location, and enable it 554 1.3 skrll if the files are found. The auto detection is enabled for native builds, 555 1.10 mrg and for cross builds configured with <samp>--with-sysroot</samp>, and without 556 1.10 mrg <samp>--with-native-system-header-dir</samp>. 557 1.3 skrll More documentation about multiarch can be found at 558 1.7 mrg <a href="https://wiki.debian.org/Multiarch">https://wiki.debian.org/Multiarch</a>. 559 1.10 mrg </p> 560 1.10 mrg </dd> 561 1.10 mrg <dt><code>--enable-sjlj-exceptions</code></dt> 562 1.10 mrg <dd><p>Force use of the <code>setjmp</code>/<code>longjmp</code>-based scheme for exceptions. 563 1.10 mrg ‘<samp>configure</samp>’ ordinarily picks the correct value based on the platform. 564 1.6 mrg Only use this option if you are sure you need a different setting. 565 1.10 mrg </p> 566 1.10 mrg </dd> 567 1.10 mrg <dt><code>--enable-vtable-verify</code></dt> 568 1.10 mrg <dd><p>Specify whether to enable or disable the vtable verification feature. 569 1.5 mrg Enabling this feature causes libstdc++ to be built with its virtual calls 570 1.5 mrg in verifiable mode. This means that, when linked with libvtv, every 571 1.5 mrg virtual call in libstdc++ will verify the vtable pointer through which the 572 1.5 mrg call will be made before actually making the call. If not linked with libvtv, 573 1.10 mrg the verifier will call stub functions (in libstdc++ itself) and do nothing. 574 1.5 mrg If vtable verification is disabled, then libstdc++ is not built with its 575 1.5 mrg virtual calls in verifiable mode at all. However the libvtv library will 576 1.10 mrg still be built (see <samp>--disable-libvtv</samp> to turn off building libvtv). 577 1.10 mrg <samp>--disable-vtable-verify</samp> is the default. 578 1.10 mrg </p> 579 1.10 mrg </dd> 580 1.12 mrg <dt><code>--disable-gcov</code></dt> 581 1.12 mrg <dd><p>Specify that the run-time library used for coverage analysis 582 1.12 mrg and associated host tools should not be built. 583 1.12 mrg </p> 584 1.12 mrg </dd> 585 1.10 mrg <dt><code>--disable-multilib</code></dt> 586 1.10 mrg <dd><p>Specify that multiple target 587 1.1 mrg libraries to support different target variants, calling 588 1.1 mrg conventions, etc. should not be built. The default is to build a 589 1.1 mrg predefined set of them. 590 1.10 mrg </p> 591 1.10 mrg <p>Some targets provide finer-grained control over which multilibs are built 592 1.10 mrg (e.g., <samp>--disable-softfloat</samp>): 593 1.10 mrg </p><dl compact="compact"> 594 1.10 mrg <dt><code>arm-*-*</code></dt> 595 1.10 mrg <dd><p>fpu, 26bit, underscore, interwork, biendian, nofmult. 596 1.10 mrg </p> 597 1.10 mrg </dd> 598 1.10 mrg <dt><code>m68*-*-*</code></dt> 599 1.10 mrg <dd><p>softfloat, m68881, m68000, m68020. 600 1.10 mrg </p> 601 1.10 mrg </dd> 602 1.10 mrg <dt><code>mips*-*-*</code></dt> 603 1.10 mrg <dd><p>single-float, biendian, softfloat. 604 1.10 mrg </p> 605 1.10 mrg </dd> 606 1.13 mrg <dt><code>msp430-*-*</code></dt> 607 1.13 mrg <dd><p>no-exceptions 608 1.13 mrg </p> 609 1.13 mrg </dd> 610 1.10 mrg <dt><code>powerpc*-*-*, rs6000*-*-*</code></dt> 611 1.10 mrg <dd><p>aix64, pthread, softfloat, powercpu, powerpccpu, powerpcos, biendian, 612 1.1 mrg sysv, aix. 613 1.10 mrg </p> 614 1.10 mrg </dd> 615 1.10 mrg </dl> 616 1.1 mrg 617 1.10 mrg </dd> 618 1.10 mrg <dt><code>--with-multilib-list=<var>list</var></code></dt> 619 1.10 mrg <dt><code>--without-multilib-list</code></dt> 620 1.10 mrg <dd><p>Specify what multilibs to build. <var>list</var> is a comma separated list of 621 1.9 mrg values, possibly consisting of a single value. Currently only implemented 622 1.12 mrg for aarch64*-*-*, arm*-*-*, riscv*-*-*, sh*-*-* and x86-64-*-linux*. The 623 1.12 mrg accepted values and meaning for each target is given below. 624 1.10 mrg </p> 625 1.10 mrg <dl compact="compact"> 626 1.10 mrg <dt><code>aarch64*-*-*</code></dt> 627 1.10 mrg <dd><p><var>list</var> is a comma separated list of <code>ilp32</code>, and <code>lp64</code> 628 1.10 mrg to enable ILP32 and LP64 run-time libraries, respectively. If 629 1.10 mrg <var>list</var> is empty, then there will be no multilibs and only the 630 1.10 mrg default run-time library will be built. If <var>list</var> is 631 1.10 mrg <code>default</code> or –with-multilib-list= is not specified, then the 632 1.10 mrg default set of libraries is selected based on the value of 633 1.10 mrg <samp>--target</samp>. 634 1.10 mrg </p> 635 1.10 mrg </dd> 636 1.10 mrg <dt><code>arm*-*-*</code></dt> 637 1.12 mrg <dd><p><var>list</var> is a comma separated list of <code>aprofile</code> and 638 1.12 mrg <code>rmprofile</code> to build multilibs for A or R and M architecture 639 1.12 mrg profiles respectively. Note that, due to some limitation of the current 640 1.12 mrg multilib framework, using the combined <code>aprofile,rmprofile</code> 641 1.12 mrg multilibs selects in some cases a less optimal multilib than when using 642 1.12 mrg the multilib profile for the architecture targetted. The special value 643 1.12 mrg <code>default</code> is also accepted and is equivalent to omitting the 644 1.12 mrg option, i.e., only the default run-time library will be enabled. 645 1.12 mrg </p> 646 1.12 mrg <p><var>list</var> may instead contain <code>@name</code>, to use the multilib 647 1.12 mrg configuration Makefile fragment <samp>name</samp> in <samp>gcc/config/arm</samp> in 648 1.12 mrg the source tree (it is part of the corresponding sources, after all). 649 1.12 mrg It is recommended, but not required, that files used for this purpose to 650 1.12 mrg be named starting with <samp>t-ml-</samp>, to make their intended purpose 651 1.12 mrg self-evident, in line with GCC conventions. Such files enable custom, 652 1.12 mrg user-chosen multilib lists to be configured. Whether multiple such 653 1.12 mrg files can be used together depends on the contents of the supplied 654 1.12 mrg files. See <samp>gcc/config/arm/t-multilib</samp> and its supplementary 655 1.12 mrg <samp>gcc/config/arm/t-*profile</samp> files for an example of what such 656 1.12 mrg Makefile fragments might look like for this version of GCC. The macros 657 1.12 mrg expected to be defined in these fragments are not stable across GCC 658 1.12 mrg releases, so make sure they define the <code>MULTILIB</code>-related macros 659 1.12 mrg expected by the version of GCC you are building. 660 1.12 mrg See “Target Makefile Fragments” in the internals manual. 661 1.10 mrg </p> 662 1.10 mrg <p>The table below gives the combination of ISAs, architectures, FPUs and 663 1.12 mrg floating-point ABIs for which multilibs are built for each predefined 664 1.12 mrg profile. The union of these options is considered when specifying both 665 1.12 mrg <code>aprofile</code> and <code>rmprofile</code>. 666 1.10 mrg </p> 667 1.10 mrg <table> 668 1.10 mrg <tr><td width="15%">Option</td><td width="28%">aprofile</td><td width="30%">rmprofile</td></tr> 669 1.10 mrg <tr><td width="15%">ISAs</td><td width="28%"><code>-marm</code> and <code>-mthumb</code></td><td width="30%"><code>-mthumb</code></td></tr> 670 1.10 mrg <tr><td width="15%">Architectures<br><br><br><br><br><br></td><td width="28%">default architecture<br> 671 1.9 mrg <code>-march=armv7-a</code><br> 672 1.9 mrg <code>-march=armv7ve</code><br> 673 1.10 mrg <code>-march=armv8-a</code><br><br><br></td><td width="30%">default architecture<br> 674 1.9 mrg <code>-march=armv6s-m</code><br> 675 1.9 mrg <code>-march=armv7-m</code><br> 676 1.9 mrg <code>-march=armv7e-m</code><br> 677 1.9 mrg <code>-march=armv8-m.base</code><br> 678 1.9 mrg <code>-march=armv8-m.main</code><br> 679 1.10 mrg <code>-march=armv7</code></td></tr> 680 1.10 mrg <tr><td width="15%">FPUs<br><br><br><br><br></td><td width="28%">none<br> 681 1.9 mrg <code>-mfpu=vfpv3-d16</code><br> 682 1.9 mrg <code>-mfpu=neon</code><br> 683 1.9 mrg <code>-mfpu=vfpv4-d16</code><br> 684 1.9 mrg <code>-mfpu=neon-vfpv4</code><br> 685 1.10 mrg <code>-mfpu=neon-fp-armv8</code></td><td width="30%">none<br> 686 1.9 mrg <code>-mfpu=vfpv3-d16</code><br> 687 1.9 mrg <code>-mfpu=fpv4-sp-d16</code><br> 688 1.9 mrg <code>-mfpu=fpv5-sp-d16</code><br> 689 1.10 mrg <code>-mfpu=fpv5-d16</code><br></td></tr> 690 1.10 mrg <tr><td width="15%">floating-point ABIs<br><br></td><td width="28%"><code>-mfloat-abi=soft</code><br> 691 1.9 mrg <code>-mfloat-abi=softfp</code><br> 692 1.10 mrg <code>-mfloat-abi=hard</code></td><td width="30%"><code>-mfloat-abi=soft</code><br> 693 1.9 mrg <code>-mfloat-abi=softfp</code><br> 694 1.10 mrg <code>-mfloat-abi=hard</code></td></tr> 695 1.10 mrg </table> 696 1.9 mrg 697 1.10 mrg </dd> 698 1.12 mrg <dt><code>riscv*-*-*</code></dt> 699 1.12 mrg <dd><p><var>list</var> is a single ABI name. The target architecture must be either 700 1.12 mrg <code>rv32gc</code> or <code>rv64gc</code>. This will build a single multilib for the 701 1.12 mrg specified architecture and ABI pair. If <code>--with-multilib-list</code> is not 702 1.12 mrg given, then a default set of multilibs is selected based on the value of 703 1.12 mrg <samp>--target</samp>. This is usually a large set of multilibs. 704 1.12 mrg </p> 705 1.12 mrg </dd> 706 1.10 mrg <dt><code>sh*-*-*</code></dt> 707 1.10 mrg <dd><p><var>list</var> is a comma separated list of CPU names. These must be of the 708 1.1 mrg form <code>sh*</code> or <code>m*</code> (in which case they match the compiler option 709 1.1 mrg for that processor). The list should not contain any endian options - 710 1.10 mrg these are handled by <samp>--with-endian</samp>. 711 1.10 mrg </p> 712 1.10 mrg <p>If <var>list</var> is empty, then there will be no multilibs for extra 713 1.1 mrg processors. The multilib for the secondary endian remains enabled. 714 1.10 mrg </p> 715 1.10 mrg <p>As a special case, if an entry in the list starts with a <code>!</code> 716 1.10 mrg (exclamation point), then it is added to the list of excluded multilibs. 717 1.10 mrg Entries of this sort should be compatible with ‘<samp>MULTILIB_EXCLUDES</samp>’ 718 1.1 mrg (once the leading <code>!</code> has been stripped). 719 1.10 mrg </p> 720 1.10 mrg <p>If <samp>--with-multilib-list</samp> is not given, then a default set of 721 1.10 mrg multilibs is selected based on the value of <samp>--target</samp>. This is 722 1.1 mrg usually the complete set of libraries, but some targets imply a more 723 1.1 mrg specialized subset. 724 1.10 mrg </p> 725 1.10 mrg <p>Example 1: to configure a compiler for SH4A only, but supporting both 726 1.10 mrg endians, with little endian being the default: 727 1.10 mrg </p><div class="smallexample"> 728 1.10 mrg <pre class="smallexample">--with-cpu=sh4a --with-endian=little,big --with-multilib-list= 729 1.10 mrg </pre></div> 730 1.9 mrg 731 1.10 mrg <p>Example 2: to configure a compiler for both SH4A and SH4AL-DSP, but with 732 1.1 mrg only little endian SH4AL: 733 1.10 mrg </p><div class="smallexample"> 734 1.10 mrg <pre class="smallexample">--with-cpu=sh4a --with-endian=little,big \ 735 1.10 mrg --with-multilib-list=sh4al,!mb/m4al 736 1.10 mrg </pre></div> 737 1.10 mrg 738 1.10 mrg </dd> 739 1.10 mrg <dt><code>x86-64-*-linux*</code></dt> 740 1.10 mrg <dd><p><var>list</var> is a comma separated list of <code>m32</code>, <code>m64</code> and 741 1.3 skrll <code>mx32</code> to enable 32-bit, 64-bit and x32 run-time libraries, 742 1.3 skrll respectively. If <var>list</var> is empty, then there will be no multilibs 743 1.3 skrll and only the default run-time library will be enabled. 744 1.10 mrg </p> 745 1.10 mrg <p>If <samp>--with-multilib-list</samp> is not given, then only 32-bit and 746 1.10 mrg 64-bit run-time libraries will be enabled. 747 1.10 mrg </p></dd> 748 1.3 skrll </dl> 749 1.3 skrll 750 1.10 mrg </dd> 751 1.10 mrg <dt><code>--with-endian=<var>endians</var></code></dt> 752 1.10 mrg <dd><p>Specify what endians to use. 753 1.1 mrg Currently only implemented for sh*-*-*. 754 1.10 mrg </p> 755 1.10 mrg <p><var>endians</var> may be one of the following: 756 1.10 mrg </p><dl compact="compact"> 757 1.10 mrg <dt><code>big</code></dt> 758 1.10 mrg <dd><p>Use big endian exclusively. 759 1.10 mrg </p></dd> 760 1.10 mrg <dt><code>little</code></dt> 761 1.10 mrg <dd><p>Use little endian exclusively. 762 1.10 mrg </p></dd> 763 1.10 mrg <dt><code>big,little</code></dt> 764 1.10 mrg <dd><p>Use big endian by default. Provide a multilib for little endian. 765 1.10 mrg </p></dd> 766 1.10 mrg <dt><code>little,big</code></dt> 767 1.10 mrg <dd><p>Use little endian by default. Provide a multilib for big endian. 768 1.10 mrg </p></dd> 769 1.1 mrg </dl> 770 1.1 mrg 771 1.10 mrg </dd> 772 1.10 mrg <dt><code>--enable-threads</code></dt> 773 1.10 mrg <dd><p>Specify that the target 774 1.1 mrg supports threads. This affects the Objective-C compiler and runtime 775 1.10 mrg library, and exception handling for other languages like C++. 776 1.1 mrg On some systems, this is the default. 777 1.10 mrg </p> 778 1.10 mrg <p>In general, the best (and, in many cases, the only known) threading 779 1.1 mrg model available will be configured for use. Beware that on some 780 1.1 mrg systems, GCC has not been taught what threading models are generally 781 1.10 mrg available for the system. In this case, <samp>--enable-threads</samp> is an 782 1.10 mrg alias for <samp>--enable-threads=single</samp>. 783 1.10 mrg </p> 784 1.10 mrg </dd> 785 1.10 mrg <dt><code>--disable-threads</code></dt> 786 1.10 mrg <dd><p>Specify that threading support should be disabled for the system. 787 1.10 mrg This is an alias for <samp>--enable-threads=single</samp>. 788 1.10 mrg </p> 789 1.10 mrg </dd> 790 1.10 mrg <dt><code>--enable-threads=<var>lib</var></code></dt> 791 1.10 mrg <dd><p>Specify that 792 1.1 mrg <var>lib</var> is the thread support library. This affects the Objective-C 793 1.1 mrg compiler and runtime library, and exception handling for other languages 794 1.9 mrg like C++. The possibilities for <var>lib</var> are: 795 1.10 mrg </p> 796 1.10 mrg <dl compact="compact"> 797 1.10 mrg <dt><code>aix</code></dt> 798 1.10 mrg <dd><p>AIX thread support. 799 1.10 mrg </p></dd> 800 1.10 mrg <dt><code>dce</code></dt> 801 1.10 mrg <dd><p>DCE thread support. 802 1.10 mrg </p></dd> 803 1.10 mrg <dt><code>lynx</code></dt> 804 1.10 mrg <dd><p>LynxOS thread support. 805 1.10 mrg </p></dd> 806 1.10 mrg <dt><code>mipssde</code></dt> 807 1.10 mrg <dd><p>MIPS SDE thread support. 808 1.10 mrg </p></dd> 809 1.10 mrg <dt><code>no</code></dt> 810 1.10 mrg <dd><p>This is an alias for ‘<samp>single</samp>’. 811 1.10 mrg </p></dd> 812 1.10 mrg <dt><code>posix</code></dt> 813 1.10 mrg <dd><p>Generic POSIX/Unix98 thread support. 814 1.10 mrg </p></dd> 815 1.10 mrg <dt><code>rtems</code></dt> 816 1.10 mrg <dd><p>RTEMS thread support. 817 1.10 mrg </p></dd> 818 1.10 mrg <dt><code>single</code></dt> 819 1.10 mrg <dd><p>Disable thread support, should work for all platforms. 820 1.10 mrg </p></dd> 821 1.10 mrg <dt><code>tpf</code></dt> 822 1.10 mrg <dd><p>TPF thread support. 823 1.10 mrg </p></dd> 824 1.10 mrg <dt><code>vxworks</code></dt> 825 1.10 mrg <dd><p>VxWorks thread support. 826 1.10 mrg </p></dd> 827 1.10 mrg <dt><code>win32</code></dt> 828 1.10 mrg <dd><p>Microsoft Win32 API thread support. 829 1.10 mrg </p></dd> 830 1.1 mrg </dl> 831 1.1 mrg 832 1.10 mrg </dd> 833 1.10 mrg <dt><code>--enable-tls</code></dt> 834 1.10 mrg <dd><p>Specify that the target supports TLS (Thread Local Storage). Usually 835 1.1 mrg configure can correctly determine if TLS is supported. In cases where 836 1.1 mrg it guesses incorrectly, TLS can be explicitly enabled or disabled with 837 1.10 mrg <samp>--enable-tls</samp> or <samp>--disable-tls</samp>. This can happen if 838 1.1 mrg the assembler supports TLS but the C library does not, or if the 839 1.1 mrg assumptions made by the configure test are incorrect. 840 1.10 mrg </p> 841 1.10 mrg </dd> 842 1.10 mrg <dt><code>--disable-tls</code></dt> 843 1.10 mrg <dd><p>Specify that the target does not support TLS. 844 1.10 mrg This is an alias for <samp>--enable-tls=no</samp>. 845 1.10 mrg </p> 846 1.10 mrg </dd> 847 1.13 mrg <dt><code>--disable-tm-clone-registry</code></dt> 848 1.13 mrg <dd><p>Disable TM clone registry in libgcc. It is enabled in libgcc by default. 849 1.13 mrg This option helps to reduce code size for embedded targets which do 850 1.13 mrg not use transactional memory. 851 1.13 mrg </p> 852 1.13 mrg </dd> 853 1.10 mrg <dt><code>--with-cpu=<var>cpu</var></code></dt> 854 1.10 mrg <dt><code>--with-cpu-32=<var>cpu</var></code></dt> 855 1.10 mrg <dt><code>--with-cpu-64=<var>cpu</var></code></dt> 856 1.10 mrg <dd><p>Specify which cpu variant the compiler should generate code for by default. 857 1.10 mrg <var>cpu</var> will be used as the default value of the <samp>-mcpu=</samp> switch. 858 1.5 mrg This option is only supported on some targets, including ARC, ARM, i386, M68k, 859 1.10 mrg PowerPC, and SPARC. It is mandatory for ARC. The <samp>--with-cpu-32</samp> and 860 1.10 mrg <samp>--with-cpu-64</samp> options specify separate default CPUs for 861 1.13 mrg 32-bit and 64-bit modes; these options are only supported for aarch64, i386, 862 1.7 mrg x86-64, PowerPC, and SPARC. 863 1.10 mrg </p> 864 1.10 mrg </dd> 865 1.10 mrg <dt><code>--with-schedule=<var>cpu</var></code></dt> 866 1.10 mrg <dt><code>--with-arch=<var>cpu</var></code></dt> 867 1.10 mrg <dt><code>--with-arch-32=<var>cpu</var></code></dt> 868 1.10 mrg <dt><code>--with-arch-64=<var>cpu</var></code></dt> 869 1.10 mrg <dt><code>--with-tune=<var>cpu</var></code></dt> 870 1.10 mrg <dt><code>--with-tune-32=<var>cpu</var></code></dt> 871 1.10 mrg <dt><code>--with-tune-64=<var>cpu</var></code></dt> 872 1.10 mrg <dt><code>--with-abi=<var>abi</var></code></dt> 873 1.10 mrg <dt><code>--with-fpu=<var>type</var></code></dt> 874 1.10 mrg <dt><code>--with-float=<var>type</var></code></dt> 875 1.10 mrg <dd><p>These configure options provide default values for the <samp>-mschedule=</samp>, 876 1.10 mrg <samp>-march=</samp>, <samp>-mtune=</samp>, <samp>-mabi=</samp>, and <samp>-mfpu=</samp> 877 1.10 mrg options and for <samp>-mhard-float</samp> or <samp>-msoft-float</samp>. As with 878 1.10 mrg <samp>--with-cpu</samp>, which switches will be accepted and acceptable values 879 1.1 mrg of the arguments depend on the target. 880 1.10 mrg </p> 881 1.10 mrg </dd> 882 1.10 mrg <dt><code>--with-mode=<var>mode</var></code></dt> 883 1.10 mrg <dd><p>Specify if the compiler should default to <samp>-marm</samp> or <samp>-mthumb</samp>. 884 1.1 mrg This option is only supported on ARM targets. 885 1.10 mrg </p> 886 1.10 mrg </dd> 887 1.10 mrg <dt><code>--with-stack-offset=<var>num</var></code></dt> 888 1.10 mrg <dd><p>This option sets the default for the -mstack-offset=<var>num</var> option, 889 1.3 skrll and will thus generally also control the setting of this option for 890 1.3 skrll libraries. This option is only supported on Epiphany targets. 891 1.10 mrg </p> 892 1.10 mrg </dd> 893 1.10 mrg <dt><code>--with-fpmath=<var>isa</var></code></dt> 894 1.10 mrg <dd><p>This options sets <samp>-mfpmath=sse</samp> by default and specifies the default 895 1.10 mrg ISA for floating-point arithmetics. You can select either ‘<samp>sse</samp>’ which 896 1.10 mrg enables <samp>-msse2</samp> or ‘<samp>avx</samp>’ which enables <samp>-mavx</samp> by default. 897 1.3 skrll This option is only supported on i386 and x86-64 targets. 898 1.10 mrg </p> 899 1.10 mrg </dd> 900 1.10 mrg <dt><code>--with-fp-32=<var>mode</var></code></dt> 901 1.10 mrg <dd><p>On MIPS targets, set the default value for the <samp>-mfp</samp> option when using 902 1.5 mrg the o32 ABI. The possibilities for <var>mode</var> are: 903 1.10 mrg </p><dl compact="compact"> 904 1.10 mrg <dt><code>32</code></dt> 905 1.10 mrg <dd><p>Use the o32 FP32 ABI extension, as with the <samp>-mfp32</samp> command-line 906 1.10 mrg option. 907 1.10 mrg </p></dd> 908 1.10 mrg <dt><code>xx</code></dt> 909 1.10 mrg <dd><p>Use the o32 FPXX ABI extension, as with the <samp>-mfpxx</samp> command-line 910 1.10 mrg option. 911 1.10 mrg </p></dd> 912 1.10 mrg <dt><code>64</code></dt> 913 1.10 mrg <dd><p>Use the o32 FP64 ABI extension, as with the <samp>-mfp64</samp> command-line 914 1.10 mrg option. 915 1.10 mrg </p></dd> 916 1.5 mrg </dl> 917 1.10 mrg <p>In the absence of this configuration option the default is to use the o32 918 1.5 mrg FP32 ABI extension. 919 1.10 mrg </p> 920 1.10 mrg </dd> 921 1.10 mrg <dt><code>--with-odd-spreg-32</code></dt> 922 1.10 mrg <dd><p>On MIPS targets, set the <samp>-modd-spreg</samp> option by default when using 923 1.5 mrg the o32 ABI. 924 1.10 mrg </p> 925 1.10 mrg </dd> 926 1.10 mrg <dt><code>--without-odd-spreg-32</code></dt> 927 1.10 mrg <dd><p>On MIPS targets, set the <samp>-mno-odd-spreg</samp> option by default when using 928 1.5 mrg the o32 ABI. This is normally used in conjunction with 929 1.10 mrg <samp>--with-fp-32=64</samp> in order to target the o32 FP64A ABI extension. 930 1.10 mrg </p> 931 1.10 mrg </dd> 932 1.10 mrg <dt><code>--with-nan=<var>encoding</var></code></dt> 933 1.10 mrg <dd><p>On MIPS targets, set the default encoding convention to use for the 934 1.5 mrg special not-a-number (NaN) IEEE 754 floating-point data. The 935 1.5 mrg possibilities for <var>encoding</var> are: 936 1.10 mrg </p><dl compact="compact"> 937 1.10 mrg <dt><code>legacy</code></dt> 938 1.10 mrg <dd><p>Use the legacy encoding, as with the <samp>-mnan=legacy</samp> command-line 939 1.10 mrg option. 940 1.10 mrg </p></dd> 941 1.10 mrg <dt><code>2008</code></dt> 942 1.10 mrg <dd><p>Use the 754-2008 encoding, as with the <samp>-mnan=2008</samp> command-line 943 1.10 mrg option. 944 1.10 mrg </p></dd> 945 1.5 mrg </dl> 946 1.10 mrg <p>To use this configuration option you must have an assembler version 947 1.10 mrg installed that supports the <samp>-mnan=</samp> command-line option too. 948 1.5 mrg In the absence of this configuration option the default convention is 949 1.10 mrg the legacy encoding, as when neither of the <samp>-mnan=2008</samp> and 950 1.10 mrg <samp>-mnan=legacy</samp> command-line options has been used. 951 1.10 mrg </p> 952 1.10 mrg </dd> 953 1.10 mrg <dt><code>--with-divide=<var>type</var></code></dt> 954 1.10 mrg <dd><p>Specify how the compiler should generate code for checking for 955 1.10 mrg division by zero. This option is only supported on the MIPS target. 956 1.1 mrg The possibilities for <var>type</var> are: 957 1.10 mrg </p><dl compact="compact"> 958 1.10 mrg <dt><code>traps</code></dt> 959 1.10 mrg <dd><p>Division by zero checks use conditional traps (this is the default on 960 1.10 mrg systems that support conditional traps). 961 1.10 mrg </p></dd> 962 1.10 mrg <dt><code>breaks</code></dt> 963 1.10 mrg <dd><p>Division by zero checks use the break instruction. 964 1.10 mrg </p></dd> 965 1.1 mrg </dl> 966 1.1 mrg 967 1.10 mrg 968 1.10 mrg </dd> 969 1.10 mrg <dt><code>--with-llsc</code></dt> 970 1.10 mrg <dd><p>On MIPS targets, make <samp>-mllsc</samp> the default when no 971 1.10 mrg <samp>-mno-llsc</samp> option is passed. This is the default for 972 1.1 mrg Linux-based targets, as the kernel will emulate them if the ISA does 973 1.1 mrg not provide them. 974 1.10 mrg </p> 975 1.10 mrg </dd> 976 1.10 mrg <dt><code>--without-llsc</code></dt> 977 1.10 mrg <dd><p>On MIPS targets, make <samp>-mno-llsc</samp> the default when no 978 1.10 mrg <samp>-mllsc</samp> option is passed. 979 1.10 mrg </p> 980 1.10 mrg </dd> 981 1.10 mrg <dt><code>--with-synci</code></dt> 982 1.10 mrg <dd><p>On MIPS targets, make <samp>-msynci</samp> the default when no 983 1.10 mrg <samp>-mno-synci</samp> option is passed. 984 1.10 mrg </p> 985 1.10 mrg </dd> 986 1.10 mrg <dt><code>--without-synci</code></dt> 987 1.10 mrg <dd><p>On MIPS targets, make <samp>-mno-synci</samp> the default when no 988 1.10 mrg <samp>-msynci</samp> option is passed. This is the default. 989 1.10 mrg </p> 990 1.10 mrg </dd> 991 1.10 mrg <dt><code>--with-lxc1-sxc1</code></dt> 992 1.10 mrg <dd><p>On MIPS targets, make <samp>-mlxc1-sxc1</samp> the default when no 993 1.10 mrg <samp>-mno-lxc1-sxc1</samp> option is passed. This is the default. 994 1.10 mrg </p> 995 1.10 mrg </dd> 996 1.10 mrg <dt><code>--without-lxc1-sxc1</code></dt> 997 1.10 mrg <dd><p>On MIPS targets, make <samp>-mno-lxc1-sxc1</samp> the default when no 998 1.10 mrg <samp>-mlxc1-sxc1</samp> option is passed. The indexed load/store 999 1.9 mrg instructions are not directly a problem but can lead to unexpected 1000 1.9 mrg behaviour when deployed in an application intended for a 32-bit address 1001 1.9 mrg space but run on a 64-bit processor. The issue is seen because all 1002 1.9 mrg known MIPS 64-bit Linux kernels execute o32 and n32 applications 1003 1.9 mrg with 64-bit addressing enabled which affects the overflow behaviour 1004 1.9 mrg of the indexed addressing mode. GCC will assume that ordinary 1005 1.9 mrg 32-bit arithmetic overflow behaviour is the same whether performed 1006 1.9 mrg as an <code>addu</code> instruction or as part of the address calculation 1007 1.9 mrg in <code>lwxc1</code> type instructions. This assumption holds true in a 1008 1.9 mrg pure 32-bit environment and can hold true in a 64-bit environment if 1009 1.9 mrg the address space is accurately set to be 32-bit for o32 and n32. 1010 1.10 mrg </p> 1011 1.10 mrg </dd> 1012 1.10 mrg <dt><code>--with-madd4</code></dt> 1013 1.10 mrg <dd><p>On MIPS targets, make <samp>-mmadd4</samp> the default when no 1014 1.10 mrg <samp>-mno-madd4</samp> option is passed. This is the default. 1015 1.10 mrg </p> 1016 1.10 mrg </dd> 1017 1.10 mrg <dt><code>--without-madd4</code></dt> 1018 1.10 mrg <dd><p>On MIPS targets, make <samp>-mno-madd4</samp> the default when no 1019 1.10 mrg <samp>-mmadd4</samp> option is passed. The <code>madd4</code> instruction 1020 1.9 mrg family can be problematic when targeting a combination of cores that 1021 1.9 mrg implement these instructions differently. There are two known cores 1022 1.9 mrg that implement these as fused operations instead of unfused (where 1023 1.9 mrg unfused is normally expected). Disabling these instructions is the 1024 1.9 mrg only way to ensure compatible code is generated; this will incur 1025 1.9 mrg a performance penalty. 1026 1.10 mrg </p> 1027 1.10 mrg </dd> 1028 1.10 mrg <dt><code>--with-mips-plt</code></dt> 1029 1.10 mrg <dd><p>On MIPS targets, make use of copy relocations and PLTs. 1030 1.1 mrg These features are extensions to the traditional 1031 1.1 mrg SVR4-based MIPS ABIs and require support from GNU binutils 1032 1.1 mrg and the runtime C library. 1033 1.10 mrg </p> 1034 1.10 mrg </dd> 1035 1.12 mrg <dt><code>--with-stack-clash-protection-guard-size=<var>size</var></code></dt> 1036 1.12 mrg <dd><p>On certain targets this option sets the default stack clash protection guard 1037 1.12 mrg size as a power of two in bytes. On AArch64 <var>size</var> is required to be either 1038 1.12 mrg 12 (4KB) or 16 (64KB). 1039 1.12 mrg </p> 1040 1.12 mrg </dd> 1041 1.10 mrg <dt><code>--enable-__cxa_atexit</code></dt> 1042 1.10 mrg <dd><p>Define if you want to use __cxa_atexit, rather than atexit, to 1043 1.10 mrg register C++ destructors for local statics and global objects. 1044 1.1 mrg This is essential for fully standards-compliant handling of 1045 1.1 mrg destructors, but requires __cxa_atexit in libc. This option is currently 1046 1.1 mrg only available on systems with GNU libc. When enabled, this will cause 1047 1.10 mrg <samp>-fuse-cxa-atexit</samp> to be passed by default. 1048 1.10 mrg </p> 1049 1.10 mrg </dd> 1050 1.10 mrg <dt><code>--enable-gnu-indirect-function</code></dt> 1051 1.10 mrg <dd><p>Define if you want to enable the <code>ifunc</code> attribute. This option is 1052 1.3 skrll currently only available on systems with GNU libc on certain targets. 1053 1.10 mrg </p> 1054 1.10 mrg </dd> 1055 1.10 mrg <dt><code>--enable-target-optspace</code></dt> 1056 1.10 mrg <dd><p>Specify that target 1057 1.10 mrg libraries should be optimized for code space instead of code speed. 1058 1.1 mrg This is the default for the m32r platform. 1059 1.10 mrg </p> 1060 1.10 mrg </dd> 1061 1.10 mrg <dt><code>--with-cpp-install-dir=<var>dirname</var></code></dt> 1062 1.10 mrg <dd><p>Specify that the user visible <code>cpp</code> program should be installed 1063 1.10 mrg in <samp><var>prefix</var>/<var>dirname</var>/cpp</samp>, in addition to <var>bindir</var>. 1064 1.10 mrg </p> 1065 1.10 mrg </dd> 1066 1.10 mrg <dt><code>--enable-comdat</code></dt> 1067 1.10 mrg <dd><p>Enable COMDAT group support. This is primarily used to override the 1068 1.1 mrg automatically detected value. 1069 1.10 mrg </p> 1070 1.10 mrg </dd> 1071 1.10 mrg <dt><code>--enable-initfini-array</code></dt> 1072 1.10 mrg <dd><p>Force the use of sections <code>.init_array</code> and <code>.fini_array</code> 1073 1.1 mrg (instead of <code>.init</code> and <code>.fini</code>) for constructors and 1074 1.10 mrg destructors. Option <samp>--disable-initfini-array</samp> has the 1075 1.1 mrg opposite effect. If neither option is specified, the configure script 1076 1.1 mrg will try to guess whether the <code>.init_array</code> and 1077 1.1 mrg <code>.fini_array</code> sections are supported and, if they are, use them. 1078 1.10 mrg </p> 1079 1.10 mrg </dd> 1080 1.10 mrg <dt><code>--enable-link-mutex</code></dt> 1081 1.10 mrg <dd><p>When building GCC, use a mutex to avoid linking the compilers for 1082 1.5 mrg multiple languages at the same time, to avoid thrashing on build 1083 1.5 mrg systems with limited free memory. The default is not to use such a mutex. 1084 1.10 mrg </p> 1085 1.10 mrg </dd> 1086 1.10 mrg <dt><code>--enable-maintainer-mode</code></dt> 1087 1.10 mrg <dd><p>The build rules that regenerate the Autoconf and Automake output files as 1088 1.10 mrg well as the GCC master message catalog <samp>gcc.pot</samp> are normally 1089 1.1 mrg disabled. This is because it can only be rebuilt if the complete source 1090 1.1 mrg tree is present. If you have changed the sources and want to rebuild the 1091 1.10 mrg catalog, configuring with <samp>--enable-maintainer-mode</samp> will enable 1092 1.1 mrg this. Note that you need a recent version of the <code>gettext</code> tools 1093 1.1 mrg to do so. 1094 1.10 mrg </p> 1095 1.10 mrg </dd> 1096 1.10 mrg <dt><code>--disable-bootstrap</code></dt> 1097 1.10 mrg <dd><p>For a native build, the default configuration is to perform 1098 1.10 mrg a 3-stage bootstrap of the compiler when ‘<samp>make</samp>’ is invoked, 1099 1.1 mrg testing that GCC can compile itself correctly. If you want to disable 1100 1.10 mrg this process, you can configure with <samp>--disable-bootstrap</samp>. 1101 1.10 mrg </p> 1102 1.10 mrg </dd> 1103 1.10 mrg <dt><code>--enable-bootstrap</code></dt> 1104 1.10 mrg <dd><p>In special cases, you may want to perform a 3-stage build 1105 1.10 mrg even if the target and host triplets are different. 1106 1.1 mrg This is possible when the host can run code compiled for 1107 1.10 mrg the target (e.g. host is i686-linux, target is i486-linux). 1108 1.1 mrg Starting from GCC 4.2, to do this you have to configure explicitly 1109 1.10 mrg with <samp>--enable-bootstrap</samp>. 1110 1.10 mrg </p> 1111 1.10 mrg </dd> 1112 1.10 mrg <dt><code>--enable-generated-files-in-srcdir</code></dt> 1113 1.10 mrg <dd><p>Neither the .c and .h files that are generated from Bison and flex nor the 1114 1.1 mrg info manuals and man pages that are built from the .texi files are present 1115 1.11 mrg in the repository development tree. When building GCC from that development tree, 1116 1.1 mrg or from one of our snapshots, those generated files are placed in your 1117 1.1 mrg build directory, which allows for the source to be in a readonly 1118 1.1 mrg directory. 1119 1.10 mrg </p> 1120 1.10 mrg <p>If you configure with <samp>--enable-generated-files-in-srcdir</samp> then those 1121 1.1 mrg generated files will go into the source directory. This is mainly intended 1122 1.1 mrg for generating release or prerelease tarballs of the GCC sources, since it 1123 1.1 mrg is not a requirement that the users of source releases to have flex, Bison, 1124 1.1 mrg or makeinfo. 1125 1.10 mrg </p> 1126 1.10 mrg </dd> 1127 1.10 mrg <dt><code>--enable-version-specific-runtime-libs</code></dt> 1128 1.10 mrg <dd><p>Specify 1129 1.1 mrg that runtime libraries should be installed in the compiler specific 1130 1.10 mrg subdirectory (<samp><var>libdir</var>/gcc</samp>) rather than the usual places. In 1131 1.10 mrg addition, ‘<samp>libstdc++</samp>’’s include files will be installed into 1132 1.1 mrg <samp><var>libdir</var></samp> unless you overruled it by using 1133 1.10 mrg <samp>--with-gxx-include-dir=<var>dirname</var></samp>. Using this option is 1134 1.1 mrg particularly useful if you intend to use several versions of GCC in 1135 1.13 mrg parallel. The default is ‘<samp>yes</samp>’ for ‘<samp>libada</samp>’, and ‘<samp>no</samp>’ for 1136 1.13 mrg the remaining libraries. 1137 1.10 mrg </p> 1138 1.10 mrg </dd> 1139 1.10 mrg <dt><code><a name="WithAixSoname"></a>--with-aix-soname=‘<samp>aix</samp>’, ‘<samp>svr4</samp>’ or ‘<samp>both</samp>’</code></dt> 1140 1.10 mrg <dd><p>Traditional AIX shared library versioning (versioned <code>Shared Object</code> 1141 1.5 mrg files as members of unversioned <code>Archive Library</code> files named 1142 1.10 mrg ‘<samp>lib.a</samp>’) causes numerous headaches for package managers. However, 1143 1.5 mrg <code>Import Files</code> as members of <code>Archive Library</code> files allow for 1144 1.5 mrg <strong>filename-based versioning</strong> of shared libraries as seen on Linux/SVR4, 1145 1.10 mrg where this is called the "SONAME". But as they prevent static linking, 1146 1.5 mrg <code>Import Files</code> may be used with <code>Runtime Linking</code> only, where the 1147 1.10 mrg linker does search for ‘<samp>libNAME.so</samp>’ before ‘<samp>libNAME.a</samp>’ library 1148 1.10 mrg filenames with the ‘<samp>-lNAME</samp>’ linker flag. 1149 1.10 mrg </p> 1150 1.10 mrg <a name="AixLdCommand"></a><p>For detailed information please refer to the AIX 1151 1.10 mrg <a href="https://www.ibm.com/support/knowledgecenter/search/%22the%20ld%20command%2C%20also%20called%20the%20linkage%20editor%20or%20binder%22">ld 1152 1.10 mrg Command</a> reference. 1153 1.10 mrg </p> 1154 1.10 mrg <p>As long as shared library creation is enabled, upon: 1155 1.10 mrg </p><dl compact="compact"> 1156 1.10 mrg <dt><code>--with-aix-soname=aix</code></dt> 1157 1.10 mrg <dt><code>--with-aix-soname=both</code></dt> 1158 1.10 mrg <dd><p>A (traditional AIX) <code>Shared Archive Library</code> file is created: 1159 1.10 mrg </p><ul> 1160 1.10 mrg <li> using the ‘<samp>libNAME.a</samp>’ filename scheme 1161 1.10 mrg </li><li> with the <code>Shared Object</code> file as archive member named 1162 1.10 mrg ‘<samp>libNAME.so.V</samp>’ (except for ‘<samp>libgcc_s</samp>’, where the <code>Shared 1163 1.10 mrg Object</code> file is named ‘<samp>shr.o</samp>’ for backwards compatibility), which 1164 1.10 mrg <ul class="no-bullet"> 1165 1.10 mrg <li>- is used for runtime loading from inside the ‘<samp>libNAME.a</samp>’ file 1166 1.10 mrg </li><li>- is used for dynamic loading via 1167 1.10 mrg <code>dlopen("libNAME.a(libNAME.so.V)", RTLD_MEMBER)</code> 1168 1.10 mrg </li><li>- is used for shared linking 1169 1.10 mrg </li><li>- is used for static linking, so no separate <code>Static Archive 1170 1.5 mrg Library</code> file is needed 1171 1.10 mrg </li></ul> 1172 1.10 mrg </li></ul> 1173 1.10 mrg </dd> 1174 1.10 mrg <dt><code>--with-aix-soname=both</code></dt> 1175 1.10 mrg <dt><code>--with-aix-soname=svr4</code></dt> 1176 1.10 mrg <dd><p>A (second) <code>Shared Archive Library</code> file is created: 1177 1.10 mrg </p><ul> 1178 1.10 mrg <li> using the ‘<samp>libNAME.so.V</samp>’ filename scheme 1179 1.10 mrg </li><li> with the <code>Shared Object</code> file as archive member named 1180 1.10 mrg ‘<samp>shr.o</samp>’, which 1181 1.10 mrg <ul class="no-bullet"> 1182 1.10 mrg <li>- is created with the <code>-G linker flag</code> 1183 1.10 mrg </li><li>- has the <code>F_LOADONLY</code> flag set 1184 1.10 mrg </li><li>- is used for runtime loading from inside the ‘<samp>libNAME.so.V</samp>’ file 1185 1.10 mrg </li><li>- is used for dynamic loading via <code>dlopen("libNAME.so.V(shr.o)", 1186 1.5 mrg RTLD_MEMBER)</code> 1187 1.10 mrg </li></ul> 1188 1.10 mrg </li><li> with the <code>Import File</code> as archive member named ‘<samp>shr.imp</samp>’, 1189 1.5 mrg which 1190 1.10 mrg <ul class="no-bullet"> 1191 1.10 mrg <li>- refers to ‘<samp>libNAME.so.V(shr.o)</samp>’ as the "SONAME", to be recorded 1192 1.5 mrg in the <code>Loader Section</code> of subsequent binaries 1193 1.10 mrg </li><li>- indicates whether ‘<samp>libNAME.so.V(shr.o)</samp>’ is 32 or 64 bit 1194 1.10 mrg </li><li>- lists all the public symbols exported by ‘<samp>lib.so.V(shr.o)</samp>’, 1195 1.10 mrg eventually decorated with the <code>‘<samp>weak</samp>’ Keyword</code> 1196 1.10 mrg </li><li>- is necessary for shared linking against ‘<samp>lib.so.V(shr.o)</samp>’ 1197 1.10 mrg </li></ul> 1198 1.10 mrg </li></ul> 1199 1.10 mrg <p>A symbolic link using the ‘<samp>libNAME.so</samp>’ filename scheme is created: 1200 1.10 mrg </p><ul> 1201 1.10 mrg <li> pointing to the ‘<samp>libNAME.so.V</samp>’ <code>Shared Archive Library</code> file 1202 1.10 mrg </li><li> to permit the <code>ld Command</code> to find ‘<samp>lib.so.V(shr.imp)</samp>’ via 1203 1.10 mrg the ‘<samp>-lNAME</samp>’ argument (requires <code>Runtime Linking</code> to be enabled) 1204 1.10 mrg </li><li> to permit dynamic loading of ‘<samp>lib.so.V(shr.o)</samp>’ without the need 1205 1.10 mrg to specify the version number via <code>dlopen("libNAME.so(shr.o)", 1206 1.5 mrg RTLD_MEMBER)</code> 1207 1.10 mrg </li></ul> 1208 1.10 mrg </dd> 1209 1.10 mrg </dl> 1210 1.5 mrg 1211 1.10 mrg <p>As long as static library creation is enabled, upon: 1212 1.10 mrg </p><dl compact="compact"> 1213 1.10 mrg <dt><code>--with-aix-soname=svr4</code></dt> 1214 1.10 mrg <dd><p>A <code>Static Archive Library</code> is created: 1215 1.10 mrg </p><ul> 1216 1.10 mrg <li> using the ‘<samp>libNAME.a</samp>’ filename scheme 1217 1.10 mrg </li><li> with all the <code>Static Object</code> files as archive members, which 1218 1.10 mrg <ul class="no-bullet"> 1219 1.10 mrg <li>- are used for static linking 1220 1.10 mrg </li></ul> 1221 1.10 mrg </li></ul> 1222 1.10 mrg </dd> 1223 1.10 mrg </dl> 1224 1.5 mrg 1225 1.10 mrg <p>While the aix-soname=‘<samp>svr4</samp>’ option does not create <code>Shared Object</code> 1226 1.5 mrg files as members of unversioned <code>Archive Library</code> files any more, package 1227 1.5 mrg managers still are responsible to 1228 1.5 mrg <a href="./specific.html#TransferAixShobj">transfer</a> <code>Shared Object</code> files 1229 1.5 mrg found as member of a previously installed unversioned <code>Archive Library</code> 1230 1.5 mrg file into the newly installed <code>Archive Library</code> file with the same 1231 1.5 mrg filename. 1232 1.10 mrg </p> 1233 1.10 mrg <p><em>WARNING:</em> Creating <code>Shared Object</code> files with <code>Runtime Linking</code> 1234 1.5 mrg enabled may bloat the TOC, eventually leading to <code>TOC overflow</code> errors, 1235 1.10 mrg requiring the use of either the <samp>-Wl,-bbigtoc</samp> linker flag (seen to 1236 1.5 mrg break with the <code>GDB</code> debugger) or some of the TOC-related compiler flags, 1237 1.5 mrg see “RS/6000 and PowerPC Options” in the main manual. 1238 1.10 mrg </p> 1239 1.10 mrg <p><samp>--with-aix-soname</samp> is currently supported by ‘<samp>libgcc_s</samp>’ only, so 1240 1.5 mrg this option is still experimental and not for normal use yet. 1241 1.10 mrg </p> 1242 1.10 mrg <p>Default is the traditional behavior <samp>--with-aix-soname=‘<samp>aix</samp>’</samp>. 1243 1.10 mrg </p> 1244 1.10 mrg </dd> 1245 1.10 mrg <dt><code>--enable-languages=<var>lang1</var>,<var>lang2</var>,…</code></dt> 1246 1.10 mrg <dd><p>Specify that only a particular subset of compilers and 1247 1.1 mrg their runtime libraries should be built. For a list of valid values for 1248 1.1 mrg <var>langN</var> you can issue the following command in the 1249 1.10 mrg <samp>gcc</samp> directory of your GCC source tree:<br> 1250 1.10 mrg </p><div class="smallexample"> 1251 1.10 mrg <pre class="smallexample">grep ^language= */config-lang.in 1252 1.10 mrg </pre></div> 1253 1.10 mrg <p>Currently, you can use any of the following: 1254 1.12 mrg <code>all</code>, <code>default</code>, <code>ada</code>, <code>c</code>, <code>c++</code>, <code>d</code>, 1255 1.12 mrg <code>fortran</code>, <code>go</code>, <code>jit</code>, <code>lto</code>, <code>objc</code>, <code>obj-c++</code>. 1256 1.10 mrg Building the Ada compiler has special requirements, see below. 1257 1.10 mrg If you do not pass this flag, or specify the option <code>default</code>, then the 1258 1.10 mrg default languages available in the <samp>gcc</samp> sub-tree will be configured. 1259 1.12 mrg Ada, D, Go, Jit, and Objective-C++ are not default languages. LTO is not a 1260 1.10 mrg default language, but is built by default because <samp>--enable-lto</samp> is 1261 1.10 mrg enabled by default. The other languages are default languages. If 1262 1.10 mrg <code>all</code> is specified, then all available languages are built. An 1263 1.10 mrg exception is <code>jit</code> language, which requires 1264 1.10 mrg <samp>--enable-host-shared</samp> to be included with <code>all</code>. 1265 1.10 mrg </p> 1266 1.10 mrg </dd> 1267 1.10 mrg <dt><code>--enable-stage1-languages=<var>lang1</var>,<var>lang2</var>,…</code></dt> 1268 1.10 mrg <dd><p>Specify that a particular subset of compilers and their runtime 1269 1.1 mrg libraries should be built with the system C compiler during stage 1 of 1270 1.1 mrg the bootstrap process, rather than only in later stages with the 1271 1.1 mrg bootstrapped C compiler. The list of valid values is the same as for 1272 1.10 mrg <samp>--enable-languages</samp>, and the option <code>all</code> will select all 1273 1.10 mrg of the languages enabled by <samp>--enable-languages</samp>. This option is 1274 1.1 mrg primarily useful for GCC development; for instance, when a development 1275 1.1 mrg version of the compiler cannot bootstrap due to compiler bugs, or when 1276 1.1 mrg one is debugging front ends other than the C front end. When this 1277 1.1 mrg option is used, one can then build the target libraries for the 1278 1.10 mrg specified languages with the stage-1 compiler by using <code>make 1279 1.10 mrg stage1-bubble all-target</code>, or run the testsuite on the stage-1 compiler 1280 1.10 mrg for the specified languages using <code>make stage1-start check-gcc</code>. 1281 1.10 mrg </p> 1282 1.10 mrg </dd> 1283 1.10 mrg <dt><code>--disable-libada</code></dt> 1284 1.10 mrg <dd><p>Specify that the run-time libraries and tools used by GNAT should not 1285 1.1 mrg be built. This can be useful for debugging, or for compatibility with 1286 1.1 mrg previous Ada build procedures, when it was required to explicitly 1287 1.10 mrg do a ‘<samp>make -C gcc gnatlib_and_tools</samp>’. 1288 1.10 mrg </p> 1289 1.10 mrg </dd> 1290 1.10 mrg <dt><code>--disable-libsanitizer</code></dt> 1291 1.10 mrg <dd><p>Specify that the run-time libraries for the various sanitizers should 1292 1.5 mrg not be built. 1293 1.10 mrg </p> 1294 1.10 mrg </dd> 1295 1.10 mrg <dt><code>--disable-libssp</code></dt> 1296 1.10 mrg <dd><p>Specify that the run-time libraries for stack smashing protection 1297 1.10 mrg should not be built or linked against. On many targets library support 1298 1.10 mrg is provided by the C library instead. 1299 1.10 mrg </p> 1300 1.10 mrg </dd> 1301 1.10 mrg <dt><code>--disable-libquadmath</code></dt> 1302 1.10 mrg <dd><p>Specify that the GCC quad-precision math library should not be built. 1303 1.3 skrll On some systems, the library is required to be linkable when building 1304 1.10 mrg the Fortran front end, unless <samp>--disable-libquadmath-support</samp> 1305 1.3 skrll is used. 1306 1.10 mrg </p> 1307 1.10 mrg </dd> 1308 1.10 mrg <dt><code>--disable-libquadmath-support</code></dt> 1309 1.10 mrg <dd><p>Specify that the Fortran front end and <code>libgfortran</code> do not add 1310 1.3 skrll support for <code>libquadmath</code> on systems supporting it. 1311 1.10 mrg </p> 1312 1.10 mrg </dd> 1313 1.10 mrg <dt><code>--disable-libgomp</code></dt> 1314 1.10 mrg <dd><p>Specify that the GNU Offloading and Multi Processing Runtime Library 1315 1.5 mrg should not be built. 1316 1.10 mrg </p> 1317 1.10 mrg </dd> 1318 1.10 mrg <dt><code>--disable-libvtv</code></dt> 1319 1.10 mrg <dd><p>Specify that the run-time libraries used by vtable verification 1320 1.5 mrg should not be built. 1321 1.10 mrg </p> 1322 1.10 mrg </dd> 1323 1.10 mrg <dt><code>--with-dwarf2</code></dt> 1324 1.10 mrg <dd><p>Specify that the compiler should 1325 1.1 mrg use DWARF 2 debugging information as the default. 1326 1.10 mrg </p> 1327 1.10 mrg </dd> 1328 1.10 mrg <dt><code>--with-advance-toolchain=<var>at</var></code></dt> 1329 1.10 mrg <dd><p>On 64-bit PowerPC Linux systems, configure the compiler to use the 1330 1.7 mrg header files, library files, and the dynamic linker from the Advance 1331 1.7 mrg Toolchain release <var>at</var> instead of the default versions that are 1332 1.7 mrg provided by the Linux distribution. In general, this option is 1333 1.7 mrg intended for the developers of GCC, and it is not intended for general 1334 1.7 mrg use. 1335 1.10 mrg </p> 1336 1.10 mrg </dd> 1337 1.10 mrg <dt><code>--enable-targets=all</code></dt> 1338 1.10 mrg <dt><code>--enable-targets=<var>target_list</var></code></dt> 1339 1.10 mrg <dd><p>Some GCC targets, e.g. powerpc64-linux, build bi-arch compilers. 1340 1.1 mrg These are compilers that are able to generate either 64-bit or 32-bit 1341 1.10 mrg code. Typically, the corresponding 32-bit target, e.g. 1342 1.1 mrg powerpc-linux for powerpc64-linux, only generates 32-bit code. This 1343 1.1 mrg option enables the 32-bit target to be a bi-arch compiler, which is 1344 1.1 mrg useful when you want a bi-arch compiler that defaults to 32-bit, and 1345 1.10 mrg you are building a bi-arch or multi-arch binutils in a combined tree. 1346 1.1 mrg On mips-linux, this will build a tri-arch compiler (ABI o32/n32/64), 1347 1.10 mrg defaulted to o32. 1348 1.3 skrll Currently, this option only affects sparc-linux, powerpc-linux, x86-linux, 1349 1.3 skrll mips-linux and s390-linux. 1350 1.10 mrg </p> 1351 1.10 mrg </dd> 1352 1.10 mrg <dt><code>--enable-default-pie</code></dt> 1353 1.10 mrg <dd><p>Turn on <samp>-fPIE</samp> and <samp>-pie</samp> by default. 1354 1.10 mrg </p> 1355 1.10 mrg </dd> 1356 1.10 mrg <dt><code>--enable-secureplt</code></dt> 1357 1.10 mrg <dd><p>This option enables <samp>-msecure-plt</samp> by default for powerpc-linux. 1358 1.1 mrg See “RS/6000 and PowerPC Options” in the main manual 1359 1.10 mrg </p> 1360 1.10 mrg </dd> 1361 1.10 mrg <dt><code>--enable-default-ssp</code></dt> 1362 1.10 mrg <dd><p>Turn on <samp>-fstack-protector-strong</samp> by default. 1363 1.10 mrg </p> 1364 1.10 mrg </dd> 1365 1.10 mrg <dt><code>--enable-cld</code></dt> 1366 1.10 mrg <dd><p>This option enables <samp>-mcld</samp> by default for 32-bit x86 targets. 1367 1.1 mrg See “i386 and x86-64 Options” in the main manual 1368 1.10 mrg </p> 1369 1.10 mrg </dd> 1370 1.12 mrg <dt><code>--enable-large-address-aware</code></dt> 1371 1.12 mrg <dd><p>The <samp>--enable-large-address-aware</samp> option arranges for MinGW 1372 1.12 mrg executables to be linked using the <samp>--large-address-aware</samp> 1373 1.12 mrg option, that enables the use of more than 2GB of memory. If GCC is 1374 1.12 mrg configured with this option, its effects can be reversed by passing the 1375 1.12 mrg <samp>-Wl,--disable-large-address-aware</samp> option to the so-configured 1376 1.12 mrg compiler driver. 1377 1.12 mrg </p> 1378 1.12 mrg </dd> 1379 1.10 mrg <dt><code>--enable-win32-registry</code></dt> 1380 1.10 mrg <dt><code>--enable-win32-registry=<var>key</var></code></dt> 1381 1.10 mrg <dt><code>--disable-win32-registry</code></dt> 1382 1.10 mrg <dd><p>The <samp>--enable-win32-registry</samp> option enables Microsoft Windows-hosted GCC 1383 1.1 mrg to look up installations paths in the registry using the following key: 1384 1.10 mrg </p> 1385 1.10 mrg <div class="smallexample"> 1386 1.10 mrg <pre class="smallexample"><code>HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\<var>key</var></code> 1387 1.10 mrg </pre></div> 1388 1.1 mrg 1389 1.10 mrg <p><var>key</var> defaults to GCC version number, and can be overridden by the 1390 1.10 mrg <samp>--enable-win32-registry=<var>key</var></samp> option. Vendors and distributors 1391 1.1 mrg who use custom installers are encouraged to provide a different key, 1392 1.1 mrg perhaps one comprised of vendor name and GCC version number, to 1393 1.1 mrg avoid conflict with existing installations. This feature is enabled 1394 1.10 mrg by default, and can be disabled by <samp>--disable-win32-registry</samp> 1395 1.1 mrg option. This option has no effect on the other hosts. 1396 1.10 mrg </p> 1397 1.10 mrg </dd> 1398 1.10 mrg <dt><code>--nfp</code></dt> 1399 1.10 mrg <dd><p>Specify that the machine does not have a floating point unit. This 1400 1.10 mrg option only applies to ‘<samp>m68k-sun-sunos<var>n</var></samp>’. On any other 1401 1.10 mrg system, <samp>--nfp</samp> has no effect. 1402 1.10 mrg </p> 1403 1.10 mrg </dd> 1404 1.10 mrg <dt><code>--enable-werror</code></dt> 1405 1.10 mrg <dt><code>--disable-werror</code></dt> 1406 1.10 mrg <dt><code>--enable-werror=yes</code></dt> 1407 1.10 mrg <dt><code>--enable-werror=no</code></dt> 1408 1.10 mrg <dd><p>When you specify this option, it controls whether certain files in the 1409 1.10 mrg compiler are built with <samp>-Werror</samp> in bootstrap stage2 and later. 1410 1.10 mrg If you don’t specify it, <samp>-Werror</samp> is turned on for the main 1411 1.1 mrg development trunk. However it defaults to off for release branches and 1412 1.10 mrg final releases. The specific files which get <samp>-Werror</samp> are 1413 1.1 mrg controlled by the Makefiles. 1414 1.10 mrg </p> 1415 1.10 mrg </dd> 1416 1.10 mrg <dt><code>--enable-checking</code></dt> 1417 1.11 mrg <dt><code>--disable-checking</code></dt> 1418 1.10 mrg <dt><code>--enable-checking=<var>list</var></code></dt> 1419 1.11 mrg <dd><p>This option controls performing internal consistency checks in the compiler. 1420 1.11 mrg It does not change the generated code, but adds error checking of the 1421 1.11 mrg requested complexity. This slows down the compiler and may only work 1422 1.11 mrg properly if you are building the compiler with GCC. 1423 1.11 mrg </p> 1424 1.11 mrg <p>When the option is not specified, the active set of checks depends on context. 1425 1.11 mrg Namely, bootstrap stage 1 defaults to ‘<samp>--enable-checking=yes</samp>’, builds 1426 1.11 mrg from release branches or release archives default to 1427 1.11 mrg ‘<samp>--enable-checking=release</samp>’, and otherwise 1428 1.11 mrg ‘<samp>--enable-checking=yes,extra</samp>’ is used. When the option is 1429 1.11 mrg specified without a <var>list</var>, the result is the same as 1430 1.11 mrg ‘<samp>--enable-checking=yes</samp>’. Likewise, ‘<samp>--disable-checking</samp>’ is 1431 1.11 mrg equivalent to ‘<samp>--enable-checking=no</samp>’. 1432 1.11 mrg </p> 1433 1.11 mrg <p>The categories of checks available in <var>list</var> are ‘<samp>yes</samp>’ (most common 1434 1.11 mrg checks ‘<samp>assert,misc,gc,gimple,rtlflag,runtime,tree,types</samp>’), ‘<samp>no</samp>’ 1435 1.11 mrg (no checks at all), ‘<samp>all</samp>’ (all but ‘<samp>valgrind</samp>’), ‘<samp>release</samp>’ 1436 1.11 mrg (cheapest checks ‘<samp>assert,runtime</samp>’) or ‘<samp>none</samp>’ (same as ‘<samp>no</samp>’). 1437 1.11 mrg ‘<samp>release</samp>’ checks are always on and to disable them 1438 1.11 mrg ‘<samp>--disable-checking</samp>’ or ‘<samp>--enable-checking=no[,<other checks>]</samp>’ 1439 1.11 mrg must be explicitly requested. Disabling assertions makes the compiler and 1440 1.11 mrg runtime slightly faster but increases the risk of undetected internal errors 1441 1.11 mrg causing wrong code to be generated. 1442 1.11 mrg </p> 1443 1.11 mrg <p>Individual checks can be enabled with these flags: ‘<samp>assert</samp>’, ‘<samp>df</samp>’, 1444 1.11 mrg ‘<samp>extra</samp>’, ‘<samp>fold</samp>’, ‘<samp>gc</samp>’, ‘<samp>gcac</samp>’, ‘<samp>gimple</samp>’, 1445 1.11 mrg ‘<samp>misc</samp>’, ‘<samp>rtl</samp>’, ‘<samp>rtlflag</samp>’, ‘<samp>runtime</samp>’, ‘<samp>tree</samp>’, 1446 1.11 mrg ‘<samp>types</samp>’ and ‘<samp>valgrind</samp>’. ‘<samp>extra</samp>’ extends ‘<samp>misc</samp>’ 1447 1.11 mrg checking with extra checks that might affect code generation and should 1448 1.11 mrg therefore not differ between stage1 and later stages in bootstrap. 1449 1.11 mrg </p> 1450 1.11 mrg <p>The ‘<samp>valgrind</samp>’ check requires the external <code>valgrind</code> simulator, 1451 1.11 mrg available from <a href="http://valgrind.org/">http://valgrind.org/</a>. The ‘<samp>rtl</samp>’ checks are 1452 1.11 mrg expensive and the ‘<samp>df</samp>’, ‘<samp>gcac</samp>’ and ‘<samp>valgrind</samp>’ checks are very 1453 1.11 mrg expensive. 1454 1.10 mrg </p> 1455 1.10 mrg </dd> 1456 1.10 mrg <dt><code>--disable-stage1-checking</code></dt> 1457 1.10 mrg <dt><code>--enable-stage1-checking</code></dt> 1458 1.10 mrg <dt><code>--enable-stage1-checking=<var>list</var></code></dt> 1459 1.11 mrg <dd><p>This option affects only bootstrap build. If no <samp>--enable-checking</samp> 1460 1.11 mrg option is specified the stage1 compiler is built with ‘<samp>yes</samp>’ checking 1461 1.11 mrg enabled, otherwise the stage1 checking flags are the same as specified by 1462 1.10 mrg <samp>--enable-checking</samp>. To build the stage1 compiler with 1463 1.10 mrg different checking options use <samp>--enable-stage1-checking</samp>. 1464 1.10 mrg The list of checking options is the same as for <samp>--enable-checking</samp>. 1465 1.1 mrg If your system is too slow or too small to bootstrap a released compiler 1466 1.10 mrg with checking for stage1 enabled, you can use ‘<samp>--disable-stage1-checking</samp>’ 1467 1.1 mrg to disable checking for the stage1 compiler. 1468 1.10 mrg </p> 1469 1.10 mrg </dd> 1470 1.10 mrg <dt><code>--enable-coverage</code></dt> 1471 1.10 mrg <dt><code>--enable-coverage=<var>level</var></code></dt> 1472 1.10 mrg <dd><p>With this option, the compiler is built to collect self coverage 1473 1.1 mrg information, every time it is run. This is for internal development 1474 1.1 mrg purposes, and only works when the compiler is being built with gcc. The 1475 1.1 mrg <var>level</var> argument controls whether the compiler is built optimized or 1476 1.10 mrg not, values are ‘<samp>opt</samp>’ and ‘<samp>noopt</samp>’. For coverage analysis you 1477 1.1 mrg want to disable optimization, for performance analysis you want to 1478 1.1 mrg enable optimization. When coverage is enabled, the default level is 1479 1.1 mrg without optimization. 1480 1.10 mrg </p> 1481 1.10 mrg </dd> 1482 1.10 mrg <dt><code>--enable-gather-detailed-mem-stats</code></dt> 1483 1.10 mrg <dd><p>When this option is specified more detailed information on memory 1484 1.1 mrg allocation is gathered. This information is printed when using 1485 1.10 mrg <samp>-fmem-report</samp>. 1486 1.10 mrg </p> 1487 1.10 mrg </dd> 1488 1.10 mrg <dt><code>--enable-valgrind-annotations</code></dt> 1489 1.10 mrg <dd><p>Mark selected memory related operations in the compiler when run under 1490 1.7 mrg valgrind to suppress false positives. 1491 1.10 mrg </p> 1492 1.10 mrg </dd> 1493 1.10 mrg <dt><code>--enable-nls</code></dt> 1494 1.10 mrg <dt><code>--disable-nls</code></dt> 1495 1.10 mrg <dd><p>The <samp>--enable-nls</samp> option enables Native Language Support (NLS), 1496 1.1 mrg which lets GCC output diagnostics in languages other than American 1497 1.1 mrg English. Native Language Support is enabled by default if not doing a 1498 1.10 mrg canadian cross build. The <samp>--disable-nls</samp> option disables NLS. 1499 1.10 mrg </p> 1500 1.10 mrg </dd> 1501 1.10 mrg <dt><code>--with-included-gettext</code></dt> 1502 1.10 mrg <dd><p>If NLS is enabled, the <samp>--with-included-gettext</samp> option causes the build 1503 1.10 mrg procedure to prefer its copy of GNU <code>gettext</code>. 1504 1.10 mrg </p> 1505 1.10 mrg </dd> 1506 1.10 mrg <dt><code>--with-catgets</code></dt> 1507 1.10 mrg <dd><p>If NLS is enabled, and if the host lacks <code>gettext</code> but has the 1508 1.1 mrg inferior <code>catgets</code> interface, the GCC build procedure normally 1509 1.10 mrg ignores <code>catgets</code> and instead uses GCC’s copy of the GNU 1510 1.10 mrg <code>gettext</code> library. The <samp>--with-catgets</samp> option causes the 1511 1.10 mrg build procedure to use the host’s <code>catgets</code> in this situation. 1512 1.10 mrg </p> 1513 1.10 mrg </dd> 1514 1.10 mrg <dt><code>--with-libiconv-prefix=<var>dir</var></code></dt> 1515 1.10 mrg <dd><p>Search for libiconv header files in <samp><var>dir</var>/include</samp> and 1516 1.10 mrg libiconv library files in <samp><var>dir</var>/lib</samp>. 1517 1.10 mrg </p> 1518 1.10 mrg </dd> 1519 1.10 mrg <dt><code>--enable-obsolete</code></dt> 1520 1.10 mrg <dd><p>Enable configuration for an obsoleted system. If you attempt to 1521 1.1 mrg configure GCC for a system (build, host, or target) which has been 1522 1.1 mrg obsoleted, and you do not specify this flag, configure will halt with an 1523 1.1 mrg error message. 1524 1.10 mrg </p> 1525 1.10 mrg <p>All support for systems which have been obsoleted in one release of GCC 1526 1.1 mrg is removed entirely in the next major release, unless someone steps 1527 1.1 mrg forward to maintain the port. 1528 1.10 mrg </p> 1529 1.10 mrg </dd> 1530 1.10 mrg <dt><code>--enable-decimal-float</code></dt> 1531 1.10 mrg <dt><code>--enable-decimal-float=yes</code></dt> 1532 1.10 mrg <dt><code>--enable-decimal-float=no</code></dt> 1533 1.10 mrg <dt><code>--enable-decimal-float=bid</code></dt> 1534 1.10 mrg <dt><code>--enable-decimal-float=dpd</code></dt> 1535 1.10 mrg <dt><code>--disable-decimal-float</code></dt> 1536 1.10 mrg <dd><p>Enable (or disable) support for the C decimal floating point extension 1537 1.1 mrg that is in the IEEE 754-2008 standard. This is enabled by default only 1538 1.1 mrg on PowerPC, i386, and x86_64 GNU/Linux systems. Other systems may also 1539 1.1 mrg support it, but require the user to specifically enable it. You can 1540 1.1 mrg optionally control which decimal floating point format is used (either 1541 1.10 mrg ‘<samp>bid</samp>’ or ‘<samp>dpd</samp>’). The ‘<samp>bid</samp>’ (binary integer decimal) 1542 1.10 mrg format is default on i386 and x86_64 systems, and the ‘<samp>dpd</samp>’ 1543 1.1 mrg (densely packed decimal) format is default on PowerPC systems. 1544 1.10 mrg </p> 1545 1.10 mrg </dd> 1546 1.10 mrg <dt><code>--enable-fixed-point</code></dt> 1547 1.10 mrg <dt><code>--disable-fixed-point</code></dt> 1548 1.10 mrg <dd><p>Enable (or disable) support for C fixed-point arithmetic. 1549 1.1 mrg This option is enabled by default for some targets (such as MIPS) which 1550 1.1 mrg have hardware-support for fixed-point operations. On other targets, you 1551 1.1 mrg may enable this option manually. 1552 1.10 mrg </p> 1553 1.10 mrg </dd> 1554 1.10 mrg <dt><code>--with-long-double-128</code></dt> 1555 1.10 mrg <dd><p>Specify if <code>long double</code> type should be 128-bit by default on selected 1556 1.1 mrg GNU/Linux architectures. If using <code>--without-long-double-128</code>, 1557 1.10 mrg <code>long double</code> will be by default 64-bit, the same as <code>double</code> type. 1558 1.1 mrg When neither of these configure options are used, the default will be 1559 1.1 mrg 128-bit <code>long double</code> when built against GNU C Library 2.4 and later, 1560 1.1 mrg 64-bit <code>long double</code> otherwise. 1561 1.10 mrg </p> 1562 1.10 mrg </dd> 1563 1.10 mrg <dt><code>--with-long-double-format=ibm</code></dt> 1564 1.10 mrg <dt><code>--with-long-double-format=ieee</code></dt> 1565 1.10 mrg <dd><p>Specify whether <code>long double</code> uses the IBM extended double format 1566 1.10 mrg or the IEEE 128-bit floating point format on PowerPC Linux systems. 1567 1.10 mrg This configuration switch will only work on little endian PowerPC 1568 1.10 mrg Linux systems and on big endian 64-bit systems where the default cpu 1569 1.10 mrg is at least power7 (i.e. <samp>--with-cpu=power7</samp>, 1570 1.10 mrg <samp>--with-cpu=power8</samp>, or <samp>--with-cpu=power9</samp> is used). 1571 1.10 mrg </p> 1572 1.10 mrg <p>If you use the <samp>--with-long-double-64</samp> configuration option, 1573 1.10 mrg the <samp>--with-long-double-format=ibm</samp> and 1574 1.10 mrg <samp>--with-long-double-format=ieee</samp> options are ignored. 1575 1.10 mrg </p> 1576 1.10 mrg <p>The default <code>long double</code> format is to use IBM extended double. 1577 1.10 mrg Until all of the libraries are converted to use IEEE 128-bit floating 1578 1.10 mrg point, it is not recommended to use 1579 1.10 mrg <samp>--with-long-double-format=ieee</samp>. 1580 1.10 mrg </p> 1581 1.10 mrg <p>On little endian PowerPC Linux systems, if you explicitly set the 1582 1.10 mrg <code>long double</code> type, it will build multilibs to allow you to 1583 1.10 mrg select either <code>long double</code> format, unless you disable multilibs 1584 1.10 mrg with the <code>--disable-multilib</code> option. At present, 1585 1.10 mrg <code>long double</code> multilibs are not built on big endian PowerPC Linux 1586 1.10 mrg systems. If you are building multilibs, you will need to configure 1587 1.10 mrg the compiler using the <samp>--with-system-zlib</samp> option. 1588 1.10 mrg </p> 1589 1.10 mrg <p>If you do not set the <code>long double</code> type explicitly, no multilibs 1590 1.10 mrg will be generated. 1591 1.10 mrg </p> 1592 1.10 mrg </dd> 1593 1.10 mrg <dt><code>--enable-fdpic</code></dt> 1594 1.10 mrg <dd><p>On SH Linux systems, generate ELF FDPIC code. 1595 1.10 mrg </p> 1596 1.10 mrg </dd> 1597 1.10 mrg <dt><code>--with-gmp=<var>pathname</var></code></dt> 1598 1.10 mrg <dt><code>--with-gmp-include=<var>pathname</var></code></dt> 1599 1.10 mrg <dt><code>--with-gmp-lib=<var>pathname</var></code></dt> 1600 1.10 mrg <dt><code>--with-mpfr=<var>pathname</var></code></dt> 1601 1.10 mrg <dt><code>--with-mpfr-include=<var>pathname</var></code></dt> 1602 1.10 mrg <dt><code>--with-mpfr-lib=<var>pathname</var></code></dt> 1603 1.10 mrg <dt><code>--with-mpc=<var>pathname</var></code></dt> 1604 1.10 mrg <dt><code>--with-mpc-include=<var>pathname</var></code></dt> 1605 1.10 mrg <dt><code>--with-mpc-lib=<var>pathname</var></code></dt> 1606 1.10 mrg <dd><p>If you want to build GCC but do not have the GMP library, the MPFR 1607 1.1 mrg library and/or the MPC library installed in a standard location and 1608 1.3 skrll do not have their sources present in the GCC source tree then you 1609 1.3 skrll can explicitly specify the directory where they are installed 1610 1.10 mrg (‘<samp>--with-gmp=<var>gmpinstalldir</var></samp>’, 1611 1.10 mrg ‘<samp>--with-mpfr=<var>mpfrinstalldir</var></samp>’, 1612 1.10 mrg ‘<samp>--with-mpc=<var>mpcinstalldir</var></samp>’). The 1613 1.10 mrg <samp>--with-gmp=<var>gmpinstalldir</var></samp> option is shorthand for 1614 1.10 mrg <samp>--with-gmp-lib=<var>gmpinstalldir</var>/lib</samp> and 1615 1.10 mrg <samp>--with-gmp-include=<var>gmpinstalldir</var>/include</samp>. Likewise the 1616 1.10 mrg <samp>--with-mpfr=<var>mpfrinstalldir</var></samp> option is shorthand for 1617 1.10 mrg <samp>--with-mpfr-lib=<var>mpfrinstalldir</var>/lib</samp> and 1618 1.10 mrg <samp>--with-mpfr-include=<var>mpfrinstalldir</var>/include</samp>, also the 1619 1.10 mrg <samp>--with-mpc=<var>mpcinstalldir</var></samp> option is shorthand for 1620 1.10 mrg <samp>--with-mpc-lib=<var>mpcinstalldir</var>/lib</samp> and 1621 1.10 mrg <samp>--with-mpc-include=<var>mpcinstalldir</var>/include</samp>. If these 1622 1.1 mrg shorthand assumptions are not correct, you can use the explicit 1623 1.3 skrll include and lib options directly. You might also need to ensure the 1624 1.3 skrll shared libraries can be found by the dynamic linker when building and 1625 1.3 skrll using GCC, for example by setting the runtime shared library path 1626 1.10 mrg variable (<code>LD_LIBRARY_PATH</code> on GNU/Linux and Solaris systems). 1627 1.10 mrg </p> 1628 1.10 mrg <p>These flags are applicable to the host platform only. When building 1629 1.3 skrll a cross compiler, they will not be used to configure target libraries. 1630 1.10 mrg </p> 1631 1.10 mrg </dd> 1632 1.10 mrg <dt><code>--with-isl=<var>pathname</var></code></dt> 1633 1.10 mrg <dt><code>--with-isl-include=<var>pathname</var></code></dt> 1634 1.10 mrg <dt><code>--with-isl-lib=<var>pathname</var></code></dt> 1635 1.10 mrg <dd><p>If you do not have the isl library installed in a standard location and you 1636 1.5 mrg want to build GCC, you can explicitly specify the directory where it is 1637 1.10 mrg installed (‘<samp>--with-isl=<var>islinstalldir</var></samp>’). The 1638 1.10 mrg <samp>--with-isl=<var>islinstalldir</var></samp> option is shorthand for 1639 1.10 mrg <samp>--with-isl-lib=<var>islinstalldir</var>/lib</samp> and 1640 1.10 mrg <samp>--with-isl-include=<var>islinstalldir</var>/include</samp>. If this 1641 1.5 mrg shorthand assumption is not correct, you can use the explicit 1642 1.1 mrg include and lib options directly. 1643 1.10 mrg </p> 1644 1.10 mrg <p>These flags are applicable to the host platform only. When building 1645 1.3 skrll a cross compiler, they will not be used to configure target libraries. 1646 1.10 mrg </p> 1647 1.10 mrg </dd> 1648 1.10 mrg <dt><code>--with-stage1-ldflags=<var>flags</var></code></dt> 1649 1.10 mrg <dd><p>This option may be used to set linker flags to be used when linking 1650 1.1 mrg stage 1 of GCC. These are also used when linking GCC if configured with 1651 1.10 mrg <samp>--disable-bootstrap</samp>. If <samp>--with-stage1-libs</samp> is not set to a 1652 1.10 mrg value, then the default is ‘<samp>-static-libstdc++ -static-libgcc</samp>’, if 1653 1.7 mrg supported. 1654 1.10 mrg </p> 1655 1.10 mrg </dd> 1656 1.10 mrg <dt><code>--with-stage1-libs=<var>libs</var></code></dt> 1657 1.10 mrg <dd><p>This option may be used to set libraries to be used when linking stage 1 1658 1.1 mrg of GCC. These are also used when linking GCC if configured with 1659 1.10 mrg <samp>--disable-bootstrap</samp>. 1660 1.10 mrg </p> 1661 1.10 mrg </dd> 1662 1.10 mrg <dt><code>--with-boot-ldflags=<var>flags</var></code></dt> 1663 1.10 mrg <dd><p>This option may be used to set linker flags to be used when linking 1664 1.7 mrg stage 2 and later when bootstrapping GCC. If –with-boot-libs 1665 1.7 mrg is not is set to a value, then the default is 1666 1.10 mrg ‘<samp>-static-libstdc++ -static-libgcc</samp>’. 1667 1.10 mrg </p> 1668 1.10 mrg </dd> 1669 1.10 mrg <dt><code>--with-boot-libs=<var>libs</var></code></dt> 1670 1.10 mrg <dd><p>This option may be used to set libraries to be used when linking stage 2 1671 1.7 mrg and later when bootstrapping GCC. 1672 1.10 mrg </p> 1673 1.10 mrg </dd> 1674 1.10 mrg <dt><code>--with-debug-prefix-map=<var>map</var></code></dt> 1675 1.10 mrg <dd><p>Convert source directory names using <samp>-fdebug-prefix-map</samp> when 1676 1.1 mrg building runtime libraries. ‘<samp><var>map</var></samp>’ is a space-separated 1677 1.10 mrg list of maps of the form ‘<samp><var>old</var>=<var>new</var></samp>’. 1678 1.10 mrg </p> 1679 1.10 mrg </dd> 1680 1.10 mrg <dt><code>--enable-linker-build-id</code></dt> 1681 1.10 mrg <dd><p>Tells GCC to pass <samp>--build-id</samp> option to the linker for all final 1682 1.10 mrg links (links performed without the <samp>-r</samp> or <samp>--relocatable</samp> 1683 1.1 mrg option), if the linker supports it. If you specify 1684 1.10 mrg <samp>--enable-linker-build-id</samp>, but your linker does not 1685 1.10 mrg support <samp>--build-id</samp> option, a warning is issued and the 1686 1.10 mrg <samp>--enable-linker-build-id</samp> option is ignored. The default is off. 1687 1.10 mrg </p> 1688 1.10 mrg </dd> 1689 1.10 mrg <dt><code>--with-linker-hash-style=<var>choice</var></code></dt> 1690 1.10 mrg <dd><p>Tells GCC to pass <samp>--hash-style=<var>choice</var></samp> option to the 1691 1.3 skrll linker for all final links. <var>choice</var> can be one of 1692 1.10 mrg ‘<samp>sysv</samp>’, ‘<samp>gnu</samp>’, and ‘<samp>both</samp>’ where ‘<samp>sysv</samp>’ is the default. 1693 1.10 mrg </p> 1694 1.10 mrg </dd> 1695 1.10 mrg <dt><code>--enable-gnu-unique-object</code></dt> 1696 1.10 mrg <dt><code>--disable-gnu-unique-object</code></dt> 1697 1.10 mrg <dd><p>Tells GCC to use the gnu_unique_object relocation for C++ template 1698 1.1 mrg static data members and inline function local statics. Enabled by 1699 1.5 mrg default for a toolchain with an assembler that accepts it and 1700 1.1 mrg GLIBC 2.11 or above, otherwise disabled. 1701 1.10 mrg </p> 1702 1.10 mrg </dd> 1703 1.10 mrg <dt><code>--with-diagnostics-color=<var>choice</var></code></dt> 1704 1.10 mrg <dd><p>Tells GCC to use <var>choice</var> as the default for <samp>-fdiagnostics-color=</samp> 1705 1.5 mrg option (if not used explicitly on the command line). <var>choice</var> 1706 1.10 mrg can be one of ‘<samp>never</samp>’, ‘<samp>auto</samp>’, ‘<samp>always</samp>’, and ‘<samp>auto-if-env</samp>’ 1707 1.13 mrg where ‘<samp>auto</samp>’ is the default. ‘<samp>auto-if-env</samp>’ makes 1708 1.13 mrg <samp>-fdiagnostics-color=auto</samp> the default if <code>GCC_COLORS</code> 1709 1.13 mrg is present and non-empty in the environment of the compiler, and 1710 1.10 mrg <samp>-fdiagnostics-color=never</samp> otherwise. 1711 1.10 mrg </p> 1712 1.10 mrg </dd> 1713 1.13 mrg <dt><code>--with-diagnostics-urls=<var>choice</var></code></dt> 1714 1.13 mrg <dd><p>Tells GCC to use <var>choice</var> as the default for <samp>-fdiagnostics-urls=</samp> 1715 1.13 mrg option (if not used explicitly on the command line). <var>choice</var> 1716 1.13 mrg can be one of ‘<samp>never</samp>’, ‘<samp>auto</samp>’, ‘<samp>always</samp>’, and ‘<samp>auto-if-env</samp>’ 1717 1.13 mrg where ‘<samp>auto</samp>’ is the default. ‘<samp>auto-if-env</samp>’ makes 1718 1.13 mrg <samp>-fdiagnostics-urls=auto</samp> the default if <code>GCC_URLS</code> 1719 1.13 mrg or <code>TERM_URLS</code> is present and non-empty in the environment of the 1720 1.13 mrg compiler, and <samp>-fdiagnostics-urls=never</samp> otherwise. 1721 1.13 mrg </p> 1722 1.13 mrg </dd> 1723 1.10 mrg <dt><code>--enable-lto</code></dt> 1724 1.10 mrg <dt><code>--disable-lto</code></dt> 1725 1.10 mrg <dd><p>Enable support for link-time optimization (LTO). This is enabled by 1726 1.10 mrg default, and may be disabled using <samp>--disable-lto</samp>. 1727 1.10 mrg </p> 1728 1.10 mrg </dd> 1729 1.10 mrg <dt><code>--enable-linker-plugin-configure-flags=FLAGS</code></dt> 1730 1.10 mrg <dt><code>--enable-linker-plugin-flags=FLAGS</code></dt> 1731 1.10 mrg <dd><p>By default, linker plugins (such as the LTO plugin) are built for the 1732 1.5 mrg host system architecture. For the case that the linker has a 1733 1.5 mrg different (but run-time compatible) architecture, these flags can be 1734 1.5 mrg specified to build plugins that are compatible to the linker. For 1735 1.5 mrg example, if you are building GCC for a 64-bit x86_64 1736 1.12 mrg (‘<samp>x86_64-pc-linux-gnu</samp>’) host system, but have a 32-bit x86 1737 1.10 mrg GNU/Linux (‘<samp>i686-pc-linux-gnu</samp>’) linker executable (which is 1738 1.5 mrg executable on the former system), you can configure GCC as follows for 1739 1.5 mrg getting compatible linker plugins: 1740 1.10 mrg </p> 1741 1.10 mrg <div class="smallexample"> 1742 1.10 mrg <pre class="smallexample">% <var>srcdir</var>/configure \ 1743 1.12 mrg --host=x86_64-pc-linux-gnu \ 1744 1.10 mrg --enable-linker-plugin-configure-flags=--host=i686-pc-linux-gnu \ 1745 1.10 mrg --enable-linker-plugin-flags='CC=gcc\ -m32\ -Wl,-rpath,[...]/i686-pc-linux-gnu/lib' 1746 1.10 mrg </pre></div> 1747 1.10 mrg 1748 1.10 mrg </dd> 1749 1.10 mrg <dt><code>--with-plugin-ld=<var>pathname</var></code></dt> 1750 1.10 mrg <dd><p>Enable an alternate linker to be used at link-time optimization (LTO) 1751 1.10 mrg link time when <samp>-fuse-linker-plugin</samp> is enabled. 1752 1.3 skrll This linker should have plugin support such as gold starting with 1753 1.10 mrg version 2.20 or GNU ld starting with version 2.21. 1754 1.10 mrg See <samp>-fuse-linker-plugin</samp> for details. 1755 1.10 mrg </p> 1756 1.10 mrg </dd> 1757 1.10 mrg <dt><code>--enable-canonical-system-headers</code></dt> 1758 1.10 mrg <dt><code>--disable-canonical-system-headers</code></dt> 1759 1.10 mrg <dd><p>Enable system header path canonicalization for <samp>libcpp</samp>. This can 1760 1.3 skrll produce shorter header file paths in diagnostics and dependency output 1761 1.3 skrll files, but these changed header paths may conflict with some compilation 1762 1.3 skrll environments. Enabled by default, and may be disabled using 1763 1.10 mrg <samp>--disable-canonical-system-headers</samp>. 1764 1.10 mrg </p> 1765 1.10 mrg </dd> 1766 1.10 mrg <dt><code>--with-glibc-version=<var>major</var>.<var>minor</var></code></dt> 1767 1.10 mrg <dd><p>Tell GCC that when the GNU C Library (glibc) is used on the target it 1768 1.5 mrg will be version <var>major</var>.<var>minor</var> or later. Normally this can 1769 1.10 mrg be detected from the C library’s header files, but this option may be 1770 1.5 mrg needed when bootstrapping a cross toolchain without the header files 1771 1.5 mrg available for building the initial bootstrap compiler. 1772 1.10 mrg </p> 1773 1.10 mrg <p>If GCC is configured with some multilibs that use glibc and some that 1774 1.10 mrg do not, this option applies only to the multilibs that use glibc. 1775 1.5 mrg However, such configurations may not work well as not all the relevant 1776 1.5 mrg configuration in GCC is on a per-multilib basis. 1777 1.10 mrg </p> 1778 1.10 mrg </dd> 1779 1.10 mrg <dt><code>--enable-as-accelerator-for=<var>target</var></code></dt> 1780 1.10 mrg <dd><p>Build as offload target compiler. Specify offload host triple by <var>target</var>. 1781 1.10 mrg </p> 1782 1.10 mrg </dd> 1783 1.10 mrg <dt><code>--enable-offload-targets=<var>target1</var>[=<var>path1</var>],…,<var>targetN</var>[=<var>pathN</var>]</code></dt> 1784 1.10 mrg <dd><p>Enable offloading to targets <var>target1</var>, …, <var>targetN</var>. 1785 1.5 mrg Offload compilers are expected to be already installed. Default search 1786 1.5 mrg path for them is <samp><var>exec-prefix</var></samp>, but it can be changed by 1787 1.10 mrg specifying paths <var>path1</var>, …, <var>pathN</var>. 1788 1.10 mrg </p> 1789 1.10 mrg <div class="smallexample"> 1790 1.10 mrg <pre class="smallexample">% <var>srcdir</var>/configure \ 1791 1.12 mrg --enable-offload-targets=x86_64-intelmicemul-linux-gnu=/path/to/x86_64/compiler,nvptx-none,hsa 1792 1.10 mrg </pre></div> 1793 1.7 mrg 1794 1.10 mrg <p>If ‘<samp>hsa</samp>’ is specified as one of the targets, the compiler will be 1795 1.7 mrg built with support for HSA GPU accelerators. Because the same 1796 1.7 mrg compiler will emit the accelerator code, no path should be specified. 1797 1.10 mrg </p> 1798 1.10 mrg </dd> 1799 1.10 mrg <dt><code>--with-hsa-runtime=<var>pathname</var></code></dt> 1800 1.10 mrg <dt><code>--with-hsa-runtime-include=<var>pathname</var></code></dt> 1801 1.10 mrg <dt><code>--with-hsa-runtime-lib=<var>pathname</var></code></dt> 1802 1.10 mrg <dd> 1803 1.10 mrg <p>If you configure GCC with HSA offloading but do not have the HSA 1804 1.7 mrg run-time library installed in a standard location then you can 1805 1.7 mrg explicitly specify the directory where they are installed. The 1806 1.10 mrg <samp>--with-hsa-runtime=<var>hsainstalldir</var></samp> option is a 1807 1.7 mrg shorthand for 1808 1.10 mrg <samp>--with-hsa-runtime-lib=<var>hsainstalldir</var>/lib</samp> and 1809 1.10 mrg <samp>--with-hsa-runtime-include=<var>hsainstalldir</var>/include</samp>. 1810 1.10 mrg </p> 1811 1.10 mrg </dd> 1812 1.10 mrg <dt><code>--enable-cet</code></dt> 1813 1.10 mrg <dt><code>--disable-cet</code></dt> 1814 1.10 mrg <dd><p>Enable building target run-time libraries with control-flow 1815 1.10 mrg instrumentation, see <samp>-fcf-protection</samp> option. When 1816 1.10 mrg <code>--enable-cet</code> is specified target libraries are configured 1817 1.10 mrg to add <samp>-fcf-protection</samp> and, if needed, other target 1818 1.10 mrg specific options to a set of building options. 1819 1.10 mrg </p> 1820 1.10 mrg <p>The option is disabled by default. When <code>--enable-cet=auto</code> 1821 1.10 mrg is used, it is enabled on Linux/x86 if target binutils 1822 1.10 mrg supports <code>Intel CET</code> instructions and disabled otherwise. 1823 1.10 mrg In this case the target libraries are configured to get additional 1824 1.10 mrg <samp>-fcf-protection</samp> option. 1825 1.12 mrg </p> 1826 1.12 mrg </dd> 1827 1.12 mrg <dt><code>--with-riscv-attribute=‘<samp>yes</samp>’, ‘<samp>no</samp>’ or ‘<samp>default</samp>’</code></dt> 1828 1.12 mrg <dd><p>Generate RISC-V attribute by default, in order to record extra build 1829 1.12 mrg information in object. 1830 1.12 mrg </p> 1831 1.12 mrg <p>The option is disabled by default. It is enabled on RISC-V/ELF (bare-metal) 1832 1.12 mrg target if target binutils supported. 1833 1.10 mrg </p></dd> 1834 1.6 mrg </dl> 1835 1.1 mrg 1836 1.10 mrg <a name="Cross-Compiler-Specific-Options"></a> 1837 1.10 mrg <h4 class="subheading">Cross-Compiler-Specific Options</h4> 1838 1.1 mrg <p>The following options only apply to building cross compilers. 1839 1.10 mrg </p> 1840 1.10 mrg <dl compact="compact"> 1841 1.13 mrg <dt><code>--with-toolexeclibdir=<var>dir</var></code></dt> 1842 1.13 mrg <dd><p>Specify the installation directory for libraries built with a cross compiler. 1843 1.13 mrg The default is <samp>${gcc_tooldir}/lib</samp>. 1844 1.13 mrg </p> 1845 1.13 mrg </dd> 1846 1.10 mrg <dt><code>--with-sysroot</code></dt> 1847 1.10 mrg <dt><code>--with-sysroot=<var>dir</var></code></dt> 1848 1.10 mrg <dd><p>Tells GCC to consider <var>dir</var> as the root of a tree that contains 1849 1.10 mrg (a subset of) the root filesystem of the target operating system. 1850 1.1 mrg Target system headers, libraries and run-time object files will be 1851 1.3 skrll searched for in there. More specifically, this acts as if 1852 1.10 mrg <samp>--sysroot=<var>dir</var></samp> was added to the default options of the built 1853 1.1 mrg compiler. The specified directory is not copied into the 1854 1.10 mrg install tree, unlike the options <samp>--with-headers</samp> and 1855 1.10 mrg <samp>--with-libs</samp> that this option obsoletes. The default value, 1856 1.10 mrg in case <samp>--with-sysroot</samp> is not given an argument, is 1857 1.10 mrg <samp>${gcc_tooldir}/sys-root</samp>. If the specified directory is a 1858 1.10 mrg subdirectory of <samp>${exec_prefix}</samp>, then it will be found relative to 1859 1.1 mrg the GCC binaries if the installation tree is moved. 1860 1.10 mrg </p> 1861 1.10 mrg <p>This option affects the system root for the compiler used to build 1862 1.1 mrg target libraries (which runs on the build system) and the compiler newly 1863 1.1 mrg installed with <code>make install</code>; it does not affect the compiler which is 1864 1.1 mrg used to build GCC itself. 1865 1.10 mrg </p> 1866 1.10 mrg <p>If you specify the <samp>--with-native-system-header-dir=<var>dirname</var></samp> 1867 1.3 skrll option then the compiler will search that directory within <var>dirname</var> for 1868 1.10 mrg native system headers rather than the default <samp>/usr/include</samp>. 1869 1.10 mrg </p> 1870 1.10 mrg </dd> 1871 1.10 mrg <dt><code>--with-build-sysroot</code></dt> 1872 1.10 mrg <dt><code>--with-build-sysroot=<var>dir</var></code></dt> 1873 1.10 mrg <dd><p>Tells GCC to consider <var>dir</var> as the system root (see 1874 1.10 mrg <samp>--with-sysroot</samp>) while building target libraries, instead of 1875 1.10 mrg the directory specified with <samp>--with-sysroot</samp>. This option is 1876 1.10 mrg only useful when you are already using <samp>--with-sysroot</samp>. You 1877 1.10 mrg can use <samp>--with-build-sysroot</samp> when you are configuring with 1878 1.10 mrg <samp>--prefix</samp> set to a directory that is different from the one in 1879 1.1 mrg which you are installing GCC and your target libraries. 1880 1.10 mrg </p> 1881 1.10 mrg <p>This option affects the system root for the compiler used to build 1882 1.1 mrg target libraries (which runs on the build system); it does not affect 1883 1.1 mrg the compiler which is used to build GCC itself. 1884 1.10 mrg </p> 1885 1.10 mrg <p>If you specify the <samp>--with-native-system-header-dir=<var>dirname</var></samp> 1886 1.3 skrll option then the compiler will search that directory within <var>dirname</var> for 1887 1.10 mrg native system headers rather than the default <samp>/usr/include</samp>. 1888 1.10 mrg </p> 1889 1.10 mrg </dd> 1890 1.10 mrg <dt><code>--with-headers</code></dt> 1891 1.10 mrg <dt><code>--with-headers=<var>dir</var></code></dt> 1892 1.10 mrg <dd><p>Deprecated in favor of <samp>--with-sysroot</samp>. 1893 1.10 mrg Specifies that target headers are available when building a cross compiler. 1894 1.1 mrg The <var>dir</var> argument specifies a directory which has the target include 1895 1.10 mrg files. These include files will be copied into the <samp>gcc</samp> install 1896 1.10 mrg directory. <em>This option with the <var>dir</var> argument is required</em> when 1897 1.10 mrg building a cross compiler, if <samp><var>prefix</var>/<var>target</var>/sys-include</samp> 1898 1.10 mrg doesn’t pre-exist. If <samp><var>prefix</var>/<var>target</var>/sys-include</samp> does 1899 1.10 mrg pre-exist, the <var>dir</var> argument may be omitted. <code>fixincludes</code> 1900 1.1 mrg will be run on these files to make them compatible with GCC. 1901 1.10 mrg </p> 1902 1.10 mrg </dd> 1903 1.10 mrg <dt><code>--without-headers</code></dt> 1904 1.10 mrg <dd><p>Tells GCC not use any target headers from a libc when building a cross 1905 1.1 mrg compiler. When crossing to GNU/Linux, you need the headers so GCC 1906 1.1 mrg can build the exception handling for libgcc. 1907 1.10 mrg </p> 1908 1.10 mrg </dd> 1909 1.10 mrg <dt><code>--with-libs</code></dt> 1910 1.10 mrg <dt><code>--with-libs="<var>dir1</var> <var>dir2</var> … <var>dirN</var>"</code></dt> 1911 1.10 mrg <dd><p>Deprecated in favor of <samp>--with-sysroot</samp>. 1912 1.1 mrg Specifies a list of directories which contain the target runtime 1913 1.10 mrg libraries. These libraries will be copied into the <samp>gcc</samp> install 1914 1.1 mrg directory. If the directory list is omitted, this option has no 1915 1.1 mrg effect. 1916 1.10 mrg </p> 1917 1.10 mrg </dd> 1918 1.10 mrg <dt><code>--with-newlib</code></dt> 1919 1.10 mrg <dd><p>Specifies that ‘<samp>newlib</samp>’ is 1920 1.1 mrg being used as the target C library. This causes <code>__eprintf</code> to be 1921 1.10 mrg omitted from <samp>libgcc.a</samp> on the assumption that it will be provided by 1922 1.10 mrg ‘<samp>newlib</samp>’. 1923 1.10 mrg </p> 1924 1.13 mrg <a name="avr"></a> 1925 1.10 mrg </dd> 1926 1.10 mrg <dt><code>--with-avrlibc</code></dt> 1927 1.13 mrg <dd><p>Only supported for the AVR target. Specifies that ‘<samp>AVR-Libc</samp>’ is 1928 1.13 mrg being used as the target C library. This causes float support 1929 1.10 mrg functions like <code>__addsf3</code> to be omitted from <samp>libgcc.a</samp> on 1930 1.10 mrg the assumption that it will be provided by <samp>libm.a</samp>. For more 1931 1.10 mrg technical details, cf. <a href="http://gcc.gnu.org/PR54461">PR54461</a>. 1932 1.13 mrg It is not supported for 1933 1.3 skrll RTEMS configurations, which currently use newlib. The option is 1934 1.3 skrll supported since version 4.7.2 and is the default in 4.8.0 and newer. 1935 1.10 mrg </p> 1936 1.10 mrg </dd> 1937 1.13 mrg <dt><code>--with-double={32|64|32,64|64,32}</code></dt> 1938 1.13 mrg <dt><code>--with-long-double={32|64|32,64|64,32|double}</code></dt> 1939 1.13 mrg <dd><p>Only supported for the AVR target since version 10. 1940 1.13 mrg Specify the default layout available for the C/C++ ‘<samp>double</samp>’ 1941 1.13 mrg and ‘<samp>long double</samp>’ type, respectively. The following rules apply: 1942 1.13 mrg </p><ul> 1943 1.13 mrg <li> The first value after the ‘<samp>=</samp>’ specifies the default layout (in bits) 1944 1.13 mrg of the type and also the default for the <samp>-mdouble=</samp> resp. 1945 1.13 mrg <samp>-mlong-double=</samp> compiler option. 1946 1.13 mrg </li><li> If more than one value is specified, respective multilib variants are 1947 1.13 mrg available, and <samp>-mdouble=</samp> resp. <samp>-mlong-double=</samp> acts 1948 1.13 mrg as a multilib option. 1949 1.13 mrg </li><li> If <samp>--with-long-double=double</samp> is specified, ‘<samp>double</samp>’ and 1950 1.13 mrg ‘<samp>long double</samp>’ will have the same layout. 1951 1.13 mrg </li><li> The defaults are <samp>--with-long-double=64,32</samp> and 1952 1.13 mrg <samp>--with-double=32,64</samp>. The default ‘<samp>double</samp>’ layout imposed by 1953 1.13 mrg the latter is compatible with older versions of the compiler that implement 1954 1.13 mrg ‘<samp>double</samp>’ as a 32-bit type, which does not comply to the language standard. 1955 1.13 mrg </li></ul> 1956 1.13 mrg <p>Not all combinations of <samp>--with-double=</samp> and 1957 1.13 mrg <samp>--with-long-double=</samp> are valid. For example, the combination 1958 1.13 mrg <samp>--with-double=32,64</samp> <samp>--with-long-double=32</samp> will be 1959 1.13 mrg rejected because the first option specifies the availability of 1960 1.13 mrg multilibs for ‘<samp>double</samp>’, whereas the second option implies 1961 1.13 mrg that ‘<samp>long double</samp>’ — and hence also ‘<samp>double</samp>’ — is always 1962 1.13 mrg 32 bits wide. 1963 1.13 mrg </p> 1964 1.13 mrg </dd> 1965 1.13 mrg <dt><code>--with-double-comparison={tristate|bool|libf7}</code></dt> 1966 1.13 mrg <dd><p>Only supported for the AVR target since version 10. 1967 1.13 mrg Specify what result format is returned by library functions that 1968 1.13 mrg compare 64-bit floating point values (<code>DFmode</code>). 1969 1.13 mrg The GCC default is ‘<samp>tristate</samp>’. If the floating point 1970 1.13 mrg implementation returns a boolean instead, set it to ‘<samp>bool</samp>’. 1971 1.13 mrg </p> 1972 1.13 mrg </dd> 1973 1.13 mrg <dt><code>--with-libf7={libgcc|math|math-symbols|no}</code></dt> 1974 1.13 mrg <dd><p>Only supported for the AVR target since version 10. 1975 1.13 mrg Specify to which degree code from LibF7 is included in libgcc. 1976 1.13 mrg LibF7 is an ad-hoc, AVR-specific, 64-bit floating point emulation 1977 1.13 mrg written in C and (inline) assembly. ‘<samp>libgcc</samp>’ adds support 1978 1.13 mrg for functions that one would usually expect in libgcc like double addition, 1979 1.13 mrg double comparisons and double conversions. ‘<samp>math</samp>’ also adds routines 1980 1.13 mrg that one would expect in <samp>libm.a</samp>, but with <code>__</code> (two underscores) 1981 1.13 mrg prepended to the symbol names as specified by <samp>math.h</samp>. 1982 1.13 mrg ‘<samp>math-symbols</samp>’ also defines weak aliases for the functions 1983 1.13 mrg declared in <samp>math.h</samp>. However, <code>--with-libf7</code> won’t 1984 1.13 mrg install no <samp>math.h</samp> header file whatsoever, this file must come 1985 1.13 mrg from elsewhere. This option sets <samp>--with-double-comparison</samp> 1986 1.13 mrg to ‘<samp>bool</samp>’. 1987 1.13 mrg </p> 1988 1.13 mrg </dd> 1989 1.10 mrg <dt><code>--with-nds32-lib=<var>library</var></code></dt> 1990 1.10 mrg <dd><p>Specifies that <var>library</var> setting is used for building <samp>libgcc.a</samp>. 1991 1.10 mrg Currently, the valid <var>library</var> is ‘<samp>newlib</samp>’ or ‘<samp>mculib</samp>’. 1992 1.5 mrg This option is only supported for the NDS32 target. 1993 1.10 mrg </p> 1994 1.10 mrg </dd> 1995 1.10 mrg <dt><code>--with-build-time-tools=<var>dir</var></code></dt> 1996 1.10 mrg <dd><p>Specifies where to find the set of target tools (assembler, linker, etc.) 1997 1.1 mrg that will be used while building GCC itself. This option can be useful 1998 1.1 mrg if the directory layouts are different between the system you are building 1999 1.1 mrg GCC on, and the system where you will deploy it. 2000 1.10 mrg </p> 2001 1.10 mrg <p>For example, on an ‘<samp>ia64-hp-hpux</samp>’ system, you may have the GNU 2002 1.10 mrg assembler and linker in <samp>/usr/bin</samp>, and the native tools in a 2003 1.6 mrg different path, and build a toolchain that expects to find the 2004 1.10 mrg native tools in <samp>/usr/bin</samp>. 2005 1.10 mrg </p> 2006 1.10 mrg <p>When you use this option, you should ensure that <var>dir</var> includes 2007 1.10 mrg <code>ar</code>, <code>as</code>, <code>ld</code>, <code>nm</code>, 2008 1.10 mrg <code>ranlib</code> and <code>strip</code> if necessary, and possibly 2009 1.10 mrg <code>objdump</code>. Otherwise, GCC may use an inconsistent set of 2010 1.10 mrg tools. 2011 1.10 mrg </p></dd> 2012 1.6 mrg </dl> 2013 1.1 mrg 2014 1.10 mrg <a name="Overriding-configure-test-results"></a> 2015 1.10 mrg <h4 class="subsubheading">Overriding <code>configure</code> test results</h4> 2016 1.1 mrg 2017 1.6 mrg <p>Sometimes, it might be necessary to override the result of some 2018 1.10 mrg <code>configure</code> test, for example in order to ease porting to a new 2019 1.10 mrg system or work around a bug in a test. The toplevel <code>configure</code> 2020 1.6 mrg script provides three variables for this: 2021 1.10 mrg </p> 2022 1.10 mrg <dl compact="compact"> 2023 1.10 mrg <dt><code>build_configargs</code></dt> 2024 1.10 mrg <dd><a name="index-build_005fconfigargs"></a> 2025 1.10 mrg <p>The contents of this variable is passed to all build <code>configure</code> 2026 1.6 mrg scripts. 2027 1.10 mrg </p> 2028 1.10 mrg </dd> 2029 1.10 mrg <dt><code>host_configargs</code></dt> 2030 1.10 mrg <dd><a name="index-host_005fconfigargs"></a> 2031 1.10 mrg <p>The contents of this variable is passed to all host <code>configure</code> 2032 1.6 mrg scripts. 2033 1.10 mrg </p> 2034 1.10 mrg </dd> 2035 1.10 mrg <dt><code>target_configargs</code></dt> 2036 1.10 mrg <dd><a name="index-target_005fconfigargs"></a> 2037 1.10 mrg <p>The contents of this variable is passed to all target <code>configure</code> 2038 1.6 mrg scripts. 2039 1.10 mrg </p> 2040 1.10 mrg </dd> 2041 1.10 mrg </dl> 2042 1.1 mrg 2043 1.10 mrg <p>In order to avoid shell and <code>make</code> quoting issues for complex 2044 1.10 mrg overrides, you can pass a setting for <code>CONFIG_SITE</code> and set 2045 1.6 mrg variables in the site file. 2046 1.10 mrg </p> 2047 1.10 mrg <a name="Objective-C-Specific-Options"></a> 2048 1.10 mrg <h4 class="subheading">Objective-C-Specific Options</h4> 2049 1.7 mrg 2050 1.9 mrg <p>The following options apply to the build of the Objective-C runtime library. 2051 1.10 mrg </p> 2052 1.10 mrg <dl compact="compact"> 2053 1.10 mrg <dt><code>--enable-objc-gc</code></dt> 2054 1.10 mrg <dd><p>Specify that an additional variant of the GNU Objective-C runtime library 2055 1.9 mrg is built, using an external build of the Boehm-Demers-Weiser garbage 2056 1.13 mrg collector (<a href="https://www.hboehm.info/gc/">https://www.hboehm.info/gc/</a>). This library needs to be 2057 1.9 mrg available for each multilib variant, unless configured with 2058 1.10 mrg <samp>--enable-objc-gc=‘<samp>auto</samp>’</samp> in which case the build of the 2059 1.9 mrg additional runtime library is skipped when not available and the build 2060 1.9 mrg continues. 2061 1.10 mrg </p> 2062 1.10 mrg </dd> 2063 1.10 mrg <dt><code>--with-target-bdw-gc=<var>list</var></code></dt> 2064 1.10 mrg <dt><code>--with-target-bdw-gc-include=<var>list</var></code></dt> 2065 1.10 mrg <dt><code>--with-target-bdw-gc-lib=<var>list</var></code></dt> 2066 1.10 mrg <dd><p>Specify search directories for the garbage collector header files and 2067 1.9 mrg libraries. <var>list</var> is a comma separated list of key value pairs of the 2068 1.10 mrg form ‘<samp><var>multilibdir</var>=<var>path</var></samp>’, where the default multilib key 2069 1.10 mrg is named as ‘<samp>.</samp>’ (dot), or is omitted (e.g. 2070 1.10 mrg ‘<samp>--with-target-bdw-gc=/opt/bdw-gc,32=/opt-bdw-gc32</samp>’). 2071 1.10 mrg </p> 2072 1.10 mrg <p>The options <samp>--with-target-bdw-gc-include</samp> and 2073 1.10 mrg <samp>--with-target-bdw-gc-lib</samp> must always be specified together 2074 1.9 mrg for each multilib variant and they take precedence over 2075 1.10 mrg <samp>--with-target-bdw-gc</samp>. If <samp>--with-target-bdw-gc-include</samp> 2076 1.9 mrg is missing values for a multilib, then the value for the default 2077 1.10 mrg multilib is used (e.g. ‘<samp>--with-target-bdw-gc-include=/opt/bdw-gc/include</samp>’ 2078 1.10 mrg ‘<samp>--with-target-bdw-gc-lib=/opt/bdw-gc/lib64,32=/opt-bdw-gc/lib32</samp>’). 2079 1.9 mrg If none of these options are specified, the library is assumed in 2080 1.10 mrg default locations. 2081 1.10 mrg </p></dd> 2082 1.6 mrg </dl> 2083 1.1 mrg 2084 1.12 mrg <a name="D-Specific-Options"></a> 2085 1.12 mrg <h4 class="subheading">D-Specific Options</h4> 2086 1.12 mrg 2087 1.12 mrg <p>The following options apply to the build of the D runtime library. 2088 1.12 mrg </p> 2089 1.12 mrg <dl compact="compact"> 2090 1.13 mrg <dt><code>--enable-libphobos-checking</code></dt> 2091 1.13 mrg <dt><code>--disable-libphobos-checking</code></dt> 2092 1.13 mrg <dt><code>--enable-libphobos-checking=<var>list</var></code></dt> 2093 1.13 mrg <dd><p>This option controls whether run-time checks and contracts are compiled into 2094 1.13 mrg the D runtime library. When the option is not specified, the library is built 2095 1.13 mrg with ‘<samp>release</samp>’ checking. When the option is specified without a 2096 1.13 mrg <var>list</var>, the result is the same as ‘<samp>--enable-libphobos-checking=yes</samp>’. 2097 1.13 mrg Likewise, ‘<samp>--disable-libphobos-checking</samp>’ is equivalent to 2098 1.13 mrg ‘<samp>--enable-libphobos-checking=no</samp>’. 2099 1.13 mrg </p> 2100 1.13 mrg <p>The categories of checks available in <var>list</var> are ‘<samp>yes</samp>’ (compiles 2101 1.13 mrg libphobos with <samp>-fno-release</samp>), ‘<samp>no</samp>’ (compiles libphobos with 2102 1.13 mrg <samp>-frelease</samp>), ‘<samp>all</samp>’ (same as ‘<samp>yes</samp>’), ‘<samp>none</samp>’ or 2103 1.13 mrg ‘<samp>release</samp>’ (same as ‘<samp>no</samp>’). 2104 1.13 mrg </p> 2105 1.13 mrg <p>Individual checks available in <var>list</var> are ‘<samp>assert</samp>’ (compiles libphobos 2106 1.13 mrg with an extra option <samp>-fassert</samp>). 2107 1.13 mrg </p> 2108 1.13 mrg </dd> 2109 1.13 mrg <dt><code>--with-libphobos-druntime-only</code></dt> 2110 1.13 mrg <dt><code>--with-libphobos-druntime-only=<var>choice</var></code></dt> 2111 1.13 mrg <dd><p>Specify whether to build only the core D runtime library (druntime), or both 2112 1.13 mrg the core and standard library (phobos) into libphobos. This is useful for 2113 1.13 mrg targets that have full support in druntime, but no or incomplete support 2114 1.13 mrg in phobos. <var>choice</var> can be one of ‘<samp>auto</samp>’, ‘<samp>yes</samp>’, and ‘<samp>no</samp>’ 2115 1.13 mrg where ‘<samp>auto</samp>’ is the default. 2116 1.13 mrg </p> 2117 1.13 mrg <p>When the option is not specified, the default choice ‘<samp>auto</samp>’ means that it 2118 1.13 mrg is inferred whether the target has support for the phobos standard library. 2119 1.13 mrg When the option is specified without a <var>choice</var>, the result is the same as 2120 1.13 mrg ‘<samp>--with-libphobos-druntime-only=yes</samp>’. 2121 1.13 mrg </p> 2122 1.13 mrg </dd> 2123 1.12 mrg <dt><code>--with-target-system-zlib</code></dt> 2124 1.12 mrg <dd><p>Use installed ‘<samp>zlib</samp>’ rather than that included with GCC. This needs 2125 1.12 mrg to be available for each multilib variant, unless configured with 2126 1.12 mrg <samp>--with-target-system-zlib=‘<samp>auto</samp>’</samp> in which case the GCC included 2127 1.12 mrg ‘<samp>zlib</samp>’ is only used when the system installed library is not available. 2128 1.12 mrg </p></dd> 2129 1.12 mrg </dl> 2130 1.12 mrg 2131 1.10 mrg <hr /> 2132 1.10 mrg <p> 2133 1.8 mrg <p><a href="./index.html">Return to the GCC Installation page</a> 2134 1.10 mrg </p> 2135 1.10 mrg 2136 1.10 mrg 2137 1.10 mrg 2138 1.10 mrg 2139 1.10 mrg 2140 1.10 mrg 2141 1.10 mrg 2142 1.10 mrg 2143 1.10 mrg 2144 1.1 mrg 2145 1.1 mrg 2146 1.10 mrg </body> 2147 1.10 mrg </html> 2148
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