1 1.11 mrg <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2 1.11 mrg <html> 3 1.15 mrg <!-- Copyright (C) 1988-2022 Free Software Foundation, Inc. 4 1.1 mrg 5 1.11 mrg Permission is granted to copy, distribute and/or modify this document 6 1.3 mrg 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 1.11 mrg license is included in the section entitled "GNU 11 1.11 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 1.11 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 1.11 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 1.11 mrg funds for GNU development. --> 22 1.14 mrg <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ --> 23 1.14 mrg <head> 24 1.14 mrg <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 25 1.13 mrg <title>Installing GCC: Configuration</title> 26 1.11 mrg 27 1.13 mrg <meta name="description" content="Installing GCC: Configuration"> 28 1.13 mrg <meta name="keywords" content="Installing GCC: Configuration"> 29 1.11 mrg <meta name="resource-type" content="document"> 30 1.11 mrg <meta name="distribution" content="global"> 31 1.11 mrg <meta name="Generator" content="makeinfo"> 32 1.11 mrg <style type="text/css"> 33 1.11 mrg <!-- 34 1.11 mrg a.summary-letter {text-decoration: none} 35 1.11 mrg blockquote.indentedblock {margin-right: 0em} 36 1.14 mrg blockquote.smallindentedblock {margin-right: 0em; font-size: smaller} 37 1.14 mrg blockquote.smallquotation {font-size: smaller} 38 1.11 mrg div.display {margin-left: 3.2em} 39 1.11 mrg div.example {margin-left: 3.2em} 40 1.14 mrg div.lisp {margin-left: 3.2em} 41 1.14 mrg div.smalldisplay {margin-left: 3.2em} 42 1.14 mrg div.smallexample {margin-left: 3.2em} 43 1.14 mrg div.smalllisp {margin-left: 3.2em} 44 1.11 mrg kbd {font-style: oblique} 45 1.11 mrg pre.display {font-family: inherit} 46 1.11 mrg pre.format {font-family: inherit} 47 1.11 mrg pre.menu-comment {font-family: serif} 48 1.11 mrg pre.menu-preformatted {font-family: serif} 49 1.14 mrg pre.smalldisplay {font-family: inherit; font-size: smaller} 50 1.14 mrg pre.smallexample {font-size: smaller} 51 1.14 mrg pre.smallformat {font-family: inherit; font-size: smaller} 52 1.14 mrg pre.smalllisp {font-size: smaller} 53 1.11 mrg span.nolinebreak {white-space: nowrap} 54 1.11 mrg span.roman {font-family: initial; font-weight: normal} 55 1.11 mrg span.sansserif {font-family: sans-serif; font-weight: normal} 56 1.11 mrg ul.no-bullet {list-style: none} 57 1.11 mrg --> 58 1.11 mrg </style> 59 1.11 mrg 60 1.11 mrg 61 1.1 mrg </head> 62 1.11 mrg 63 1.11 mrg <body lang="en"> 64 1.13 mrg <h1 class="settitle" align="center">Installing GCC: Configuration</h1> 65 1.11 mrg 66 1.11 mrg 67 1.11 mrg 68 1.11 mrg 69 1.11 mrg 70 1.11 mrg 71 1.11 mrg 72 1.11 mrg 73 1.11 mrg 74 1.11 mrg 75 1.11 mrg 76 1.11 mrg 77 1.11 mrg 78 1.11 mrg 79 1.11 mrg 80 1.11 mrg 81 1.11 mrg 82 1.11 mrg 83 1.11 mrg 84 1.14 mrg <a name="index-Configuration"></a> 85 1.14 mrg <a name="index-Installing-GCC_003a-Configuration"></a> 86 1.11 mrg 87 1.11 mrg <p>Like most GNU software, GCC must be configured before it can be built. 88 1.10 mrg This document describes the recommended configuration procedure 89 1.10 mrg for both native and cross targets. 90 1.11 mrg </p> 91 1.11 mrg <p>We use <var>srcdir</var> to refer to the toplevel source directory for 92 1.10 mrg GCC; we use <var>objdir</var> to refer to the toplevel build/object directory. 93 1.11 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 1.11 mrg </p> 99 1.11 mrg <p>If either <var>srcdir</var> or <var>objdir</var> is located on an automounted NFS 100 1.11 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 1.11 mrg problems. To avoid this issue, set the <code>PWDCMD</code> environment 103 1.11 mrg variable to an automounter-aware <code>pwd</code> command, e.g., 104 1.11 mrg <code>pawd</code> or ‘<samp>amq -w</samp>’, during the configuration and build 105 1.1 mrg phases. 106 1.11 mrg </p> 107 1.11 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 1.11 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 1.11 mrg </p> 114 1.11 mrg <p>If you have previously built GCC in the same directory for a 115 1.11 mrg different target machine, do ‘<samp>make distclean</samp>’ to delete all files 116 1.11 mrg that might be invalid. One of the files this deletes is <samp>Makefile</samp>; 117 1.11 mrg if ‘<samp>make distclean</samp>’ complains that <samp>Makefile</samp> does not exist 118 1.11 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 1.11 mrg </p> 123 1.11 mrg <p>Second, when configuring a native system, either <code>cc</code> or 124 1.11 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 1.11 mrg </p> 128 1.1 mrg 129 1.11 mrg <p>To configure GCC: 130 1.11 mrg </p> 131 1.14 mrg <div class="smallexample"> 132 1.14 mrg <pre class="smallexample">% mkdir <var>objdir</var> 133 1.11 mrg % cd <var>objdir</var> 134 1.11 mrg % <var>srcdir</var>/configure [<var>options</var>] [<var>target</var>] 135 1.11 mrg </pre></div> 136 1.1 mrg 137 1.14 mrg <a name="Distributor-options"></a> 138 1.14 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 1.11 mrg </p> 144 1.11 mrg <dl compact="compact"> 145 1.14 mrg <dt><code>--with-pkgversion=<var>version</var></code></dt> 146 1.11 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 1.11 mrg included in the output of <code>gcc --version</code>. This suffix does 149 1.11 mrg not replace the default version string, only the ‘<samp>GCC</samp>’ part. 150 1.11 mrg </p> 151 1.11 mrg <p>The default value is ‘<samp>GCC</samp>’. 152 1.11 mrg </p> 153 1.11 mrg </dd> 154 1.14 mrg <dt><code>--with-bugurl=<var>url</var></code></dt> 155 1.11 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 1.11 mrg </p> 159 1.11 mrg <p>The default value refers to the FSF’s GCC bug tracker. 160 1.11 mrg </p> 161 1.11 mrg </dd> 162 1.14 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 1.14 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 1.11 mrg </dl> 178 1.1 mrg 179 1.15 mrg <a name="Host_002c-Build-and-Target-specification"></a> 180 1.15 mrg <h3 class="heading">Host, Build and Target specification</h3> 181 1.1 mrg 182 1.15 mrg <p>Specify the host, build and target machine configurations. You do this 183 1.15 mrg when you run the <samp>configure</samp> script. 184 1.15 mrg </p> 185 1.15 mrg <p>The <em>build</em> machine is the system which you are using, the 186 1.15 mrg <em>host</em> machine is the system where you want to run the resulting 187 1.15 mrg compiler (normally the build machine), and the <em>target</em> machine is 188 1.15 mrg the system for which you want the compiler to generate code. 189 1.15 mrg </p> 190 1.15 mrg <p>If you are building a compiler to produce code for the machine it runs 191 1.15 mrg on (a native compiler), you normally do not need to specify any operands 192 1.15 mrg to <samp>configure</samp>; it will try to guess the type of machine you are on 193 1.15 mrg and use that as the build, host and target machines. So you don’t need 194 1.15 mrg to specify a configuration when building a native compiler unless 195 1.15 mrg <samp>configure</samp> cannot figure out what your configuration is or guesses 196 1.15 mrg wrong. 197 1.15 mrg </p> 198 1.15 mrg <p>In those cases, specify the build machine’s <em>configuration name</em> 199 1.15 mrg with the <samp>--host</samp> option; the host and target will default to be 200 1.15 mrg the same as the host machine. 201 1.15 mrg </p> 202 1.15 mrg <p>Here is an example: 203 1.15 mrg </p> 204 1.15 mrg <div class="smallexample"> 205 1.15 mrg <pre class="smallexample">./configure --host=x86_64-pc-linux-gnu 206 1.15 mrg </pre></div> 207 1.1 mrg 208 1.15 mrg <p>A configuration name may be canonical or it may be more or less 209 1.15 mrg abbreviated (<samp>config.sub</samp> script produces canonical versions). 210 1.15 mrg </p> 211 1.15 mrg <p>A canonical configuration name has three parts, separated by dashes. 212 1.15 mrg It looks like this: ‘<samp><var>cpu</var>-<var>company</var>-<var>system</var></samp>’. 213 1.15 mrg </p> 214 1.15 mrg <p>Here are the possible CPU types: 215 1.15 mrg </p> 216 1.15 mrg <blockquote> 217 1.15 mrg <p>aarch64, aarch64_be, alpha, alpha64, amdgcn, arc, arceb, arm, armeb, avr, bfin, 218 1.15 mrg bpf, cr16, cris, csky, epiphany, fido, fr30, frv, ft32, h8300, hppa, hppa2.0, 219 1.15 mrg hppa64, i486, i686, ia64, iq2000, lm32, loongarch64, m32c, m32r, m32rle, m68k, 220 1.15 mrg mcore, microblaze, microblazeel, mips, mips64, mips64el, mips64octeon, 221 1.15 mrg mips64orion, mips64vr, mipsel, mipsisa32, mipsisa32r2, mipsisa64, mipsisa64r2, 222 1.15 mrg mipsisa64r2el, mipsisa64sb1, mipsisa64sr71k, mipstx39, mmix, mn10300, moxie, 223 1.15 mrg msp430, nds32be, nds32le, nios2, nvptx, or1k, pdp11, powerpc, powerpc64, 224 1.15 mrg powerpc64le, powerpcle, pru, riscv32, riscv32be, riscv64, riscv64be, rl78, rx, 225 1.15 mrg s390, s390x, sh, shle, sparc, sparc64, tic6x, tilegx, tilegxbe, tilepro, v850, 226 1.15 mrg v850e, v850e1, vax, visium, x86_64, xstormy16, xtensa 227 1.15 mrg </p></blockquote> 228 1.15 mrg 229 1.15 mrg <p>Here is a list of system types: 230 1.15 mrg </p> 231 1.15 mrg <blockquote> 232 1.15 mrg <p>aix<var>version</var>, amdhsa, aout, cygwin, darwin<var>version</var>, 233 1.15 mrg eabi, eabialtivec, eabisim, eabisimaltivec, elf, elf32, 234 1.15 mrg elfbare, elfoabi, freebsd<var>version</var>, gnu, hpux, hpux<var>version</var>, 235 1.15 mrg kfreebsd-gnu, kopensolaris-gnu, linux-androideabi, linux-gnu, 236 1.15 mrg linux-gnu_altivec, linux-musl, linux-uclibc, lynxos, mingw32, mingw32crt, 237 1.15 mrg mmixware, msdosdjgpp, netbsd, netbsdelf<var>version</var>, nto-qnx, openbsd, 238 1.15 mrg rtems, solaris<var>version</var>, symbianelf, tpf, uclinux, uclinux_eabi, vms, 239 1.15 mrg vxworks, vxworksae, vxworksmils 240 1.15 mrg </p></blockquote> 241 1.11 mrg 242 1.14 mrg <a name="Options-specification"></a> 243 1.14 mrg <h3 class="heading">Options specification</h3> 244 1.1 mrg 245 1.1 mrg <p>Use <var>options</var> to override several configure time options for 246 1.11 mrg GCC. A list of supported <var>options</var> follows; ‘<samp>configure 247 1.11 mrg --help</samp>’ may list other options, but those not listed below may not 248 1.1 mrg work and should not normally be used. 249 1.11 mrg </p> 250 1.11 mrg <p>Note that each <samp>--enable</samp> option has a corresponding 251 1.11 mrg <samp>--disable</samp> option and that each <samp>--with</samp> option has a 252 1.11 mrg corresponding <samp>--without</samp> option. 253 1.11 mrg </p> 254 1.11 mrg <dl compact="compact"> 255 1.14 mrg <dt><code>--prefix=<var>dirname</var></code></dt> 256 1.11 mrg <dd><p>Specify the toplevel installation 257 1.1 mrg directory. This is the recommended way to install the tools into a directory 258 1.1 mrg other than the default. The toplevel installation directory defaults to 259 1.11 mrg <samp>/usr/local</samp>. 260 1.11 mrg </p> 261 1.11 mrg <p>We <strong>highly</strong> recommend against <var>dirname</var> being the same or a 262 1.1 mrg subdirectory of <var>objdir</var> or vice versa. If specifying a directory 263 1.11 mrg beneath a user’s home directory tree, some shells will not expand 264 1.11 mrg <var>dirname</var> correctly if it contains the ‘<samp>~</samp>’ metacharacter; use 265 1.11 mrg <code>$HOME</code> instead. 266 1.11 mrg </p> 267 1.11 mrg <p>The following standard <code>autoconf</code> options are supported. Normally you 268 1.1 mrg should not need to use these options. 269 1.11 mrg </p><dl compact="compact"> 270 1.14 mrg <dt><code>--exec-prefix=<var>dirname</var></code></dt> 271 1.11 mrg <dd><p>Specify the toplevel installation directory for architecture-dependent 272 1.1 mrg files. The default is <samp><var>prefix</var></samp>. 273 1.11 mrg </p> 274 1.11 mrg </dd> 275 1.14 mrg <dt><code>--bindir=<var>dirname</var></code></dt> 276 1.11 mrg <dd><p>Specify the installation directory for the executables called by users 277 1.11 mrg (such as <code>gcc</code> and <code>g++</code>). The default is 278 1.11 mrg <samp><var>exec-prefix</var>/bin</samp>. 279 1.11 mrg </p> 280 1.11 mrg </dd> 281 1.14 mrg <dt><code>--libdir=<var>dirname</var></code></dt> 282 1.11 mrg <dd><p>Specify the installation directory for object code libraries and 283 1.11 mrg internal data files of GCC. The default is <samp><var>exec-prefix</var>/lib</samp>. 284 1.11 mrg </p> 285 1.11 mrg </dd> 286 1.14 mrg <dt><code>--libexecdir=<var>dirname</var></code></dt> 287 1.11 mrg <dd><p>Specify the installation directory for internal executables of GCC. 288 1.11 mrg The default is <samp><var>exec-prefix</var>/libexec</samp>. 289 1.11 mrg </p> 290 1.11 mrg </dd> 291 1.14 mrg <dt><code>--with-slibdir=<var>dirname</var></code></dt> 292 1.11 mrg <dd><p>Specify the installation directory for the shared libgcc library. The 293 1.1 mrg default is <samp><var>libdir</var></samp>. 294 1.11 mrg </p> 295 1.11 mrg </dd> 296 1.14 mrg <dt><code>--datarootdir=<var>dirname</var></code></dt> 297 1.11 mrg <dd><p>Specify the root of the directory tree for read-only architecture-independent 298 1.11 mrg data files referenced by GCC. The default is <samp><var>prefix</var>/share</samp>. 299 1.11 mrg </p> 300 1.11 mrg </dd> 301 1.14 mrg <dt><code>--infodir=<var>dirname</var></code></dt> 302 1.11 mrg <dd><p>Specify the installation directory for documentation in info format. 303 1.11 mrg The default is <samp><var>datarootdir</var>/info</samp>. 304 1.11 mrg </p> 305 1.11 mrg </dd> 306 1.14 mrg <dt><code>--datadir=<var>dirname</var></code></dt> 307 1.11 mrg <dd><p>Specify the installation directory for some architecture-independent 308 1.1 mrg data files referenced by GCC. The default is <samp><var>datarootdir</var></samp>. 309 1.11 mrg </p> 310 1.11 mrg </dd> 311 1.14 mrg <dt><code>--docdir=<var>dirname</var></code></dt> 312 1.11 mrg <dd><p>Specify the installation directory for documentation files (other 313 1.11 mrg than Info) for GCC. The default is <samp><var>datarootdir</var>/doc</samp>. 314 1.11 mrg </p> 315 1.11 mrg </dd> 316 1.14 mrg <dt><code>--htmldir=<var>dirname</var></code></dt> 317 1.11 mrg <dd><p>Specify the installation directory for HTML documentation files. 318 1.1 mrg The default is <samp><var>docdir</var></samp>. 319 1.11 mrg </p> 320 1.11 mrg </dd> 321 1.14 mrg <dt><code>--pdfdir=<var>dirname</var></code></dt> 322 1.11 mrg <dd><p>Specify the installation directory for PDF documentation files. 323 1.1 mrg The default is <samp><var>docdir</var></samp>. 324 1.11 mrg </p> 325 1.11 mrg </dd> 326 1.14 mrg <dt><code>--mandir=<var>dirname</var></code></dt> 327 1.11 mrg <dd><p>Specify the installation directory for manual pages. The default is 328 1.11 mrg <samp><var>datarootdir</var>/man</samp>. (Note that the manual pages are only extracts 329 1.1 mrg from the full GCC manuals, which are provided in Texinfo format. The manpages 330 1.1 mrg are derived by an automatic conversion process from parts of the full 331 1.1 mrg manual.) 332 1.11 mrg </p> 333 1.11 mrg </dd> 334 1.14 mrg <dt><code>--with-gxx-include-dir=<var>dirname</var></code></dt> 335 1.11 mrg <dd><p>Specify 336 1.1 mrg the installation directory for G++ header files. The default depends 337 1.1 mrg on other configuration options, and differs between cross and native 338 1.1 mrg configurations. 339 1.11 mrg </p> 340 1.11 mrg </dd> 341 1.14 mrg <dt><code>--with-specs=<var>specs</var></code></dt> 342 1.11 mrg <dd><p>Specify additional command line driver SPECS. 343 1.3 mrg This can be useful if you need to turn on a non-standard feature by 344 1.11 mrg default without modifying the compiler’s source code, for instance 345 1.11 mrg <samp>--with-specs=%{!fcommon:%{!fno-common:-fno-common}}</samp>. 346 1.3 mrg See “Spec Files” in the main manual 347 1.11 mrg </p> 348 1.11 mrg </dd> 349 1.11 mrg </dl> 350 1.3 mrg 351 1.11 mrg </dd> 352 1.14 mrg <dt><code>--program-prefix=<var>prefix</var></code></dt> 353 1.11 mrg <dd><p>GCC supports some transformations of the names of its programs when 354 1.1 mrg installing them. This option prepends <var>prefix</var> to the names of 355 1.1 mrg programs to install in <var>bindir</var> (see above). For example, specifying 356 1.11 mrg <samp>--program-prefix=foo-</samp> would result in ‘<samp>gcc</samp>’ 357 1.11 mrg being installed as <samp>/usr/local/bin/foo-gcc</samp>. 358 1.11 mrg </p> 359 1.11 mrg </dd> 360 1.14 mrg <dt><code>--program-suffix=<var>suffix</var></code></dt> 361 1.11 mrg <dd><p>Appends <var>suffix</var> to the names of programs to install in <var>bindir</var> 362 1.11 mrg (see above). For example, specifying <samp>--program-suffix=-3.1</samp> 363 1.11 mrg would result in ‘<samp>gcc</samp>’ being installed as 364 1.11 mrg <samp>/usr/local/bin/gcc-3.1</samp>. 365 1.11 mrg </p> 366 1.11 mrg </dd> 367 1.14 mrg <dt><code>--program-transform-name=<var>pattern</var></code></dt> 368 1.11 mrg <dd><p>Applies the ‘<samp>sed</samp>’ script <var>pattern</var> to be applied to the names 369 1.1 mrg of programs to install in <var>bindir</var> (see above). <var>pattern</var> has to 370 1.11 mrg consist of one or more basic ‘<samp>sed</samp>’ editing commands, separated by 371 1.11 mrg semicolons. For example, if you want the ‘<samp>gcc</samp>’ program name to be 372 1.11 mrg transformed to the installed program <samp>/usr/local/bin/myowngcc</samp> and 373 1.11 mrg the ‘<samp>g++</samp>’ program name to be transformed to 374 1.11 mrg <samp>/usr/local/bin/gspecial++</samp> without changing other program names, 375 1.1 mrg you could use the pattern 376 1.11 mrg <samp>--program-transform-name='s/^gcc$/myowngcc/; s/^g++$/gspecial++/'</samp> 377 1.1 mrg to achieve this effect. 378 1.11 mrg </p> 379 1.11 mrg <p>All three options can be combined and used together, resulting in more 380 1.1 mrg complex conversion patterns. As a basic rule, <var>prefix</var> (and 381 1.1 mrg <var>suffix</var>) are prepended (appended) before further transformations 382 1.1 mrg can happen with a special transformation script <var>pattern</var>. 383 1.11 mrg </p> 384 1.11 mrg <p>As currently implemented, this option only takes effect for native 385 1.11 mrg builds; cross compiler binaries’ names are not transformed even when a 386 1.1 mrg transformation is explicitly asked for by one of these options. 387 1.11 mrg </p> 388 1.11 mrg <p>For native builds, some of the installed programs are also installed 389 1.1 mrg with the target alias in front of their name, as in 390 1.11 mrg ‘<samp>i686-pc-linux-gnu-gcc</samp>’. All of the above transformations happen 391 1.1 mrg before the target alias is prepended to the name—so, specifying 392 1.11 mrg <samp>--program-prefix=foo-</samp> and <samp>program-suffix=-3.1</samp>, the 393 1.1 mrg resulting binary would be installed as 394 1.11 mrg <samp>/usr/local/bin/i686-pc-linux-gnu-foo-gcc-3.1</samp>. 395 1.11 mrg </p> 396 1.11 mrg <p>As a last shortcoming, none of the installed Ada programs are 397 1.1 mrg transformed yet, which will be fixed in some time. 398 1.11 mrg </p> 399 1.11 mrg </dd> 400 1.14 mrg <dt><code>--with-local-prefix=<var>dirname</var></code></dt> 401 1.11 mrg <dd><p>Specify the 402 1.1 mrg installation directory for local include files. The default is 403 1.11 mrg <samp>/usr/local</samp>. Specify this option if you want the compiler to 404 1.11 mrg search directory <samp><var>dirname</var>/include</samp> for locally installed 405 1.11 mrg header files <em>instead</em> of <samp>/usr/local/include</samp>. 406 1.11 mrg </p> 407 1.11 mrg <p>You should specify <samp>--with-local-prefix</samp> <strong>only</strong> if your 408 1.11 mrg site has a different convention (not <samp>/usr/local</samp>) for where to put 409 1.1 mrg site-specific files. 410 1.11 mrg </p> 411 1.11 mrg <p>The default value for <samp>--with-local-prefix</samp> is <samp>/usr/local</samp> 412 1.11 mrg regardless of the value of <samp>--prefix</samp>. Specifying 413 1.11 mrg <samp>--prefix</samp> has no effect on which directory GCC searches for 414 1.1 mrg local header files. This may seem counterintuitive, but actually it is 415 1.1 mrg logical. 416 1.11 mrg </p> 417 1.11 mrg <p>The purpose of <samp>--prefix</samp> is to specify where to <em>install 418 1.11 mrg GCC</em>. The local header files in <samp>/usr/local/include</samp>—if you put 419 1.1 mrg any in that directory—are not part of GCC. They are part of other 420 1.1 mrg programs—perhaps many others. (GCC installs its own header files in 421 1.11 mrg another directory which is based on the <samp>--prefix</samp> value.) 422 1.11 mrg </p> 423 1.11 mrg <p>Both the local-prefix include directory and the GCC-prefix include 424 1.11 mrg directory are part of GCC’s “system include” directories. Although these 425 1.1 mrg two directories are not fixed, they need to be searched in the proper 426 1.1 mrg order for the correct processing of the include_next directive. The 427 1.1 mrg local-prefix include directory is searched before the GCC-prefix 428 1.1 mrg include directory. Another characteristic of system include directories 429 1.1 mrg is that pedantic warnings are turned off for headers in these directories. 430 1.11 mrg </p> 431 1.11 mrg <p>Some autoconf macros add <samp>-I <var>directory</var></samp> options to the 432 1.1 mrg compiler command line, to ensure that directories containing installed 433 1.11 mrg packages’ headers are searched. When <var>directory</var> is one of GCC’s 434 1.1 mrg system include directories, GCC will ignore the option so that system 435 1.1 mrg directories continue to be processed in the correct order. This 436 1.1 mrg may result in a search order different from what was specified but the 437 1.1 mrg directory will still be searched. 438 1.11 mrg </p> 439 1.11 mrg <p>GCC automatically searches for ordinary libraries using 440 1.11 mrg <code>GCC_EXEC_PREFIX</code>. Thus, when the same installation prefix is 441 1.1 mrg used for both GCC and packages, GCC will automatically search for 442 1.1 mrg both headers and libraries. This provides a configuration that is 443 1.1 mrg easy to use. GCC behaves in a manner similar to that when it is 444 1.11 mrg installed as a system compiler in <samp>/usr</samp>. 445 1.11 mrg </p> 446 1.11 mrg <p>Sites that need to install multiple versions of GCC may not want to 447 1.1 mrg use the above simple configuration. It is possible to use the 448 1.11 mrg <samp>--program-prefix</samp>, <samp>--program-suffix</samp> and 449 1.11 mrg <samp>--program-transform-name</samp> options to install multiple versions 450 1.1 mrg into a single directory, but it may be simpler to use different prefixes 451 1.11 mrg and the <samp>--with-local-prefix</samp> option to specify the location of the 452 1.1 mrg site-specific files for each version. It will then be necessary for 453 1.1 mrg users to specify explicitly the location of local site libraries 454 1.11 mrg (e.g., with <code>LIBRARY_PATH</code>). 455 1.11 mrg </p> 456 1.11 mrg <p>The same value can be used for both <samp>--with-local-prefix</samp> and 457 1.11 mrg <samp>--prefix</samp> provided it is not <samp>/usr</samp>. This can be used 458 1.11 mrg to avoid the default search of <samp>/usr/local/include</samp>. 459 1.11 mrg </p> 460 1.11 mrg <p><strong>Do not</strong> specify <samp>/usr</samp> as the <samp>--with-local-prefix</samp>! 461 1.11 mrg The directory you use for <samp>--with-local-prefix</samp> <strong>must not</strong> 462 1.11 mrg contain any of the system’s standard header files. If it did contain 463 1.1 mrg them, certain programs would be miscompiled (including GNU Emacs, on 464 1.1 mrg certain targets), because this would override and nullify the header 465 1.11 mrg file corrections made by the <code>fixincludes</code> script. 466 1.11 mrg </p> 467 1.11 mrg <p>Indications are that people who use this option use it based on mistaken 468 1.1 mrg ideas of what it is for. People use it as if it specified where to 469 1.1 mrg install part of GCC. Perhaps they make this assumption because 470 1.1 mrg installing GCC creates the directory. 471 1.11 mrg </p> 472 1.11 mrg </dd> 473 1.14 mrg <dt><code>--with-gcc-major-version-only</code></dt> 474 1.11 mrg <dd><p>Specifies that GCC should use only the major number rather than 475 1.10 mrg <var>major</var>.<var>minor</var>.<var>patchlevel</var> in filesystem paths. 476 1.11 mrg </p> 477 1.11 mrg </dd> 478 1.14 mrg <dt><code>--with-native-system-header-dir=<var>dirname</var></code></dt> 479 1.11 mrg <dd><p>Specifies that <var>dirname</var> is the directory that contains native system 480 1.11 mrg header files, rather than <samp>/usr/include</samp>. This option is most useful 481 1.3 mrg if you are creating a compiler that should be isolated from the system 482 1.3 mrg as much as possible. It is most commonly used with the 483 1.11 mrg <samp>--with-sysroot</samp> option and will cause GCC to search 484 1.3 mrg <var>dirname</var> inside the system root specified by that option. 485 1.11 mrg </p> 486 1.11 mrg </dd> 487 1.14 mrg <dt><code>--enable-shared[=<var>package</var>[,…]]</code></dt> 488 1.11 mrg <dd><p>Build shared versions of libraries, if shared libraries are supported on 489 1.1 mrg the target platform. Unlike GCC 2.95.x and earlier, shared libraries 490 1.1 mrg are enabled by default on all platforms that support shared libraries. 491 1.11 mrg </p> 492 1.11 mrg <p>If a list of packages is given as an argument, build shared libraries 493 1.1 mrg only for the listed packages. For other packages, only static libraries 494 1.1 mrg will be built. Package names currently recognized in the GCC tree are 495 1.11 mrg ‘<samp>libgcc</samp>’ (also known as ‘<samp>gcc</samp>’), ‘<samp>libstdc++</samp>’ (not 496 1.11 mrg ‘<samp>libstdc++-v3</samp>’), ‘<samp>libffi</samp>’, ‘<samp>zlib</samp>’, ‘<samp>boehm-gc</samp>’, 497 1.12 mrg ‘<samp>ada</samp>’, ‘<samp>libada</samp>’, ‘<samp>libgo</samp>’, ‘<samp>libobjc</samp>’, and ‘<samp>libphobos</samp>’. 498 1.11 mrg Note ‘<samp>libiberty</samp>’ does not support shared libraries at all. 499 1.11 mrg </p> 500 1.11 mrg <p>Use <samp>--disable-shared</samp> to build only static libraries. Note that 501 1.11 mrg <samp>--disable-shared</samp> does not accept a list of package names as 502 1.11 mrg argument, only <samp>--enable-shared</samp> does. 503 1.11 mrg </p> 504 1.11 mrg <p>Contrast with <samp>--enable-host-shared</samp>, which affects <em>host</em> 505 1.5 mrg code. 506 1.11 mrg </p> 507 1.11 mrg </dd> 508 1.14 mrg <dt><code>--enable-host-shared</code></dt> 509 1.11 mrg <dd><p>Specify that the <em>host</em> code should be built into position-independent 510 1.5 mrg machine code (with -fPIC), allowing it to be used within shared libraries, 511 1.5 mrg but yielding a slightly slower compiler. 512 1.11 mrg </p> 513 1.11 mrg <p>This option is required when building the libgccjit.so library. 514 1.11 mrg </p> 515 1.11 mrg <p>Contrast with <samp>--enable-shared</samp>, which affects <em>target</em> 516 1.5 mrg libraries. 517 1.11 mrg </p> 518 1.11 mrg </dd> 519 1.14 mrg <dt><code><a name="with-gnu-as"></a>--with-gnu-as</code></dt> 520 1.11 mrg <dd><p>Specify that the compiler should assume that the 521 1.1 mrg assembler it finds is the GNU assembler. However, this does not modify 522 1.1 mrg the rules to find an assembler and will result in confusion if the 523 1.1 mrg assembler found is not actually the GNU assembler. (Confusion may also 524 1.1 mrg result if the compiler finds the GNU assembler but has not been 525 1.11 mrg configured with <samp>--with-gnu-as</samp>.) If you have more than one 526 1.1 mrg assembler installed on your system, you may want to use this option in 527 1.11 mrg connection with <samp>--with-as=<var>pathname</var></samp> or 528 1.11 mrg <samp>--with-build-time-tools=<var>pathname</var></samp>. 529 1.11 mrg </p> 530 1.11 mrg <p>The following systems are the only ones where it makes a difference 531 1.1 mrg whether you use the GNU assembler. On any other system, 532 1.11 mrg <samp>--with-gnu-as</samp> has no effect. 533 1.11 mrg </p> 534 1.11 mrg <ul> 535 1.11 mrg <li> ‘<samp>hppa1.0-<var>any</var>-<var>any</var></samp>’ 536 1.11 mrg </li><li> ‘<samp>hppa1.1-<var>any</var>-<var>any</var></samp>’ 537 1.11 mrg </li><li> ‘<samp>sparc-sun-solaris2.<var>any</var></samp>’ 538 1.11 mrg </li><li> ‘<samp>sparc64-<var>any</var>-solaris2.<var>any</var></samp>’ 539 1.11 mrg </li></ul> 540 1.11 mrg 541 1.11 mrg </dd> 542 1.14 mrg <dt><code><a name="with-as"></a>--with-as=<var>pathname</var></code></dt> 543 1.11 mrg <dd><p>Specify that the compiler should use the assembler pointed to by 544 1.1 mrg <var>pathname</var>, rather than the one found by the standard rules to find 545 1.1 mrg an assembler, which are: 546 1.11 mrg </p><ul> 547 1.11 mrg <li> Unless GCC is being built with a cross compiler, check the 548 1.11 mrg <samp><var>libexec</var>/gcc/<var>target</var>/<var>version</var></samp> directory. 549 1.11 mrg <var>libexec</var> defaults to <samp><var>exec-prefix</var>/libexec</samp>; 550 1.1 mrg <var>exec-prefix</var> defaults to <var>prefix</var>, which 551 1.11 mrg defaults to <samp>/usr/local</samp> unless overridden by the 552 1.11 mrg <samp>--prefix=<var>pathname</var></samp> switch described above. <var>target</var> 553 1.11 mrg is the target system triple, such as ‘<samp>sparc-sun-solaris2.7</samp>’, and 554 1.1 mrg <var>version</var> denotes the GCC version, such as 3.0. 555 1.1 mrg 556 1.11 mrg </li><li> If the target system is the same that you are building on, check 557 1.11 mrg operating system specific directories (e.g. <samp>/usr/ccs/bin</samp> on 558 1.13 mrg Solaris 2). 559 1.1 mrg 560 1.11 mrg </li><li> Check in the <code>PATH</code> for a tool whose name is prefixed by the 561 1.1 mrg target system triple. 562 1.1 mrg 563 1.11 mrg </li><li> Check in the <code>PATH</code> for a tool whose name is not prefixed by the 564 1.1 mrg target system triple, if the host and target system triple are 565 1.1 mrg the same (in other words, we use a host tool if it can be used for 566 1.11 mrg the target as well). 567 1.11 mrg </li></ul> 568 1.1 mrg 569 1.11 mrg <p>You may want to use <samp>--with-as</samp> if no assembler 570 1.1 mrg is installed in the directories listed above, or if you have multiple 571 1.1 mrg assemblers installed and want to choose one that is not found by the 572 1.1 mrg above rules. 573 1.11 mrg </p> 574 1.11 mrg </dd> 575 1.14 mrg <dt><code><a name="with-gnu-ld"></a>--with-gnu-ld</code></dt> 576 1.11 mrg <dd><p>Same as <a href="#with-gnu-as"><samp>--with-gnu-as</samp></a> 577 1.1 mrg but for the linker. 578 1.11 mrg </p> 579 1.11 mrg </dd> 580 1.14 mrg <dt><code>--with-ld=<var>pathname</var></code></dt> 581 1.11 mrg <dd><p>Same as <a href="#with-as"><samp>--with-as</samp></a> 582 1.1 mrg but for the linker. 583 1.11 mrg </p> 584 1.11 mrg </dd> 585 1.14 mrg <dt><code>--with-dsymutil=<var>pathname</var></code></dt> 586 1.13 mrg <dd><p>Same as <a href="#with-as"><samp>--with-as</samp></a> 587 1.13 mrg but for the debug linker (only used on Darwin platforms so far). 588 1.13 mrg </p> 589 1.13 mrg </dd> 590 1.14 mrg <dt><code>--with-tls=<var>dialect</var></code></dt> 591 1.11 mrg <dd><p>Specify the default TLS dialect, for systems were there is a choice. 592 1.3 mrg For ARM targets, possible values for <var>dialect</var> are <code>gnu</code> or 593 1.3 mrg <code>gnu2</code>, which select between the original GNU dialect and the GNU TLS 594 1.3 mrg descriptor-based dialect. 595 1.11 mrg </p> 596 1.11 mrg </dd> 597 1.14 mrg <dt><code>--enable-multiarch</code></dt> 598 1.11 mrg <dd><p>Specify whether to enable or disable multiarch support. The default is 599 1.3 mrg to check for glibc start files in a multiarch location, and enable it 600 1.3 mrg if the files are found. The auto detection is enabled for native builds, 601 1.11 mrg and for cross builds configured with <samp>--with-sysroot</samp>, and without 602 1.11 mrg <samp>--with-native-system-header-dir</samp>. 603 1.3 mrg More documentation about multiarch can be found at 604 1.7 mrg <a href="https://wiki.debian.org/Multiarch">https://wiki.debian.org/Multiarch</a>. 605 1.11 mrg </p> 606 1.11 mrg </dd> 607 1.14 mrg <dt><code>--enable-sjlj-exceptions</code></dt> 608 1.11 mrg <dd><p>Force use of the <code>setjmp</code>/<code>longjmp</code>-based scheme for exceptions. 609 1.11 mrg ‘<samp>configure</samp>’ ordinarily picks the correct value based on the platform. 610 1.6 mrg Only use this option if you are sure you need a different setting. 611 1.11 mrg </p> 612 1.11 mrg </dd> 613 1.14 mrg <dt><code>--enable-vtable-verify</code></dt> 614 1.11 mrg <dd><p>Specify whether to enable or disable the vtable verification feature. 615 1.5 mrg Enabling this feature causes libstdc++ to be built with its virtual calls 616 1.5 mrg in verifiable mode. This means that, when linked with libvtv, every 617 1.5 mrg virtual call in libstdc++ will verify the vtable pointer through which the 618 1.5 mrg call will be made before actually making the call. If not linked with libvtv, 619 1.11 mrg the verifier will call stub functions (in libstdc++ itself) and do nothing. 620 1.5 mrg If vtable verification is disabled, then libstdc++ is not built with its 621 1.5 mrg virtual calls in verifiable mode at all. However the libvtv library will 622 1.11 mrg still be built (see <samp>--disable-libvtv</samp> to turn off building libvtv). 623 1.11 mrg <samp>--disable-vtable-verify</samp> is the default. 624 1.11 mrg </p> 625 1.11 mrg </dd> 626 1.14 mrg <dt><code>--disable-gcov</code></dt> 627 1.12 mrg <dd><p>Specify that the run-time library used for coverage analysis 628 1.12 mrg and associated host tools should not be built. 629 1.12 mrg </p> 630 1.12 mrg </dd> 631 1.14 mrg <dt><code>--disable-multilib</code></dt> 632 1.11 mrg <dd><p>Specify that multiple target 633 1.1 mrg libraries to support different target variants, calling 634 1.1 mrg conventions, etc. should not be built. The default is to build a 635 1.1 mrg predefined set of them. 636 1.11 mrg </p> 637 1.11 mrg <p>Some targets provide finer-grained control over which multilibs are built 638 1.11 mrg (e.g., <samp>--disable-softfloat</samp>): 639 1.11 mrg </p><dl compact="compact"> 640 1.14 mrg <dt><code>arm-*-*</code></dt> 641 1.11 mrg <dd><p>fpu, 26bit, underscore, interwork, biendian, nofmult. 642 1.11 mrg </p> 643 1.11 mrg </dd> 644 1.14 mrg <dt><code>m68*-*-*</code></dt> 645 1.11 mrg <dd><p>softfloat, m68881, m68000, m68020. 646 1.11 mrg </p> 647 1.11 mrg </dd> 648 1.14 mrg <dt><code>mips*-*-*</code></dt> 649 1.11 mrg <dd><p>single-float, biendian, softfloat. 650 1.11 mrg </p> 651 1.11 mrg </dd> 652 1.14 mrg <dt><code>msp430-*-*</code></dt> 653 1.13 mrg <dd><p>no-exceptions 654 1.13 mrg </p> 655 1.13 mrg </dd> 656 1.14 mrg <dt><code>powerpc*-*-*, rs6000*-*-*</code></dt> 657 1.11 mrg <dd><p>aix64, pthread, softfloat, powercpu, powerpccpu, powerpcos, biendian, 658 1.1 mrg sysv, aix. 659 1.11 mrg </p> 660 1.11 mrg </dd> 661 1.11 mrg </dl> 662 1.1 mrg 663 1.11 mrg </dd> 664 1.14 mrg <dt><code>--with-multilib-list=<var>list</var></code></dt> 665 1.14 mrg <dt><code>--without-multilib-list</code></dt> 666 1.11 mrg <dd><p>Specify what multilibs to build. <var>list</var> is a comma separated list of 667 1.10 mrg values, possibly consisting of a single value. Currently only implemented 668 1.15 mrg for aarch64*-*-*, arm*-*-*, loongarch64-*-*, riscv*-*-*, sh*-*-* and 669 1.15 mrg x86-64-*-linux*. The accepted values and meaning for each target is given 670 1.15 mrg below. 671 1.11 mrg </p> 672 1.11 mrg <dl compact="compact"> 673 1.14 mrg <dt><code>aarch64*-*-*</code></dt> 674 1.11 mrg <dd><p><var>list</var> is a comma separated list of <code>ilp32</code>, and <code>lp64</code> 675 1.11 mrg to enable ILP32 and LP64 run-time libraries, respectively. If 676 1.11 mrg <var>list</var> is empty, then there will be no multilibs and only the 677 1.11 mrg default run-time library will be built. If <var>list</var> is 678 1.11 mrg <code>default</code> or –with-multilib-list= is not specified, then the 679 1.11 mrg default set of libraries is selected based on the value of 680 1.11 mrg <samp>--target</samp>. 681 1.11 mrg </p> 682 1.11 mrg </dd> 683 1.14 mrg <dt><code>arm*-*-*</code></dt> 684 1.12 mrg <dd><p><var>list</var> is a comma separated list of <code>aprofile</code> and 685 1.12 mrg <code>rmprofile</code> to build multilibs for A or R and M architecture 686 1.12 mrg profiles respectively. Note that, due to some limitation of the current 687 1.12 mrg multilib framework, using the combined <code>aprofile,rmprofile</code> 688 1.12 mrg multilibs selects in some cases a less optimal multilib than when using 689 1.12 mrg the multilib profile for the architecture targetted. The special value 690 1.12 mrg <code>default</code> is also accepted and is equivalent to omitting the 691 1.12 mrg option, i.e., only the default run-time library will be enabled. 692 1.12 mrg </p> 693 1.12 mrg <p><var>list</var> may instead contain <code>@name</code>, to use the multilib 694 1.12 mrg configuration Makefile fragment <samp>name</samp> in <samp>gcc/config/arm</samp> in 695 1.12 mrg the source tree (it is part of the corresponding sources, after all). 696 1.12 mrg It is recommended, but not required, that files used for this purpose to 697 1.12 mrg be named starting with <samp>t-ml-</samp>, to make their intended purpose 698 1.12 mrg self-evident, in line with GCC conventions. Such files enable custom, 699 1.12 mrg user-chosen multilib lists to be configured. Whether multiple such 700 1.12 mrg files can be used together depends on the contents of the supplied 701 1.12 mrg files. See <samp>gcc/config/arm/t-multilib</samp> and its supplementary 702 1.12 mrg <samp>gcc/config/arm/t-*profile</samp> files for an example of what such 703 1.12 mrg Makefile fragments might look like for this version of GCC. The macros 704 1.12 mrg expected to be defined in these fragments are not stable across GCC 705 1.12 mrg releases, so make sure they define the <code>MULTILIB</code>-related macros 706 1.12 mrg expected by the version of GCC you are building. 707 1.12 mrg See “Target Makefile Fragments” in the internals manual. 708 1.11 mrg </p> 709 1.11 mrg <p>The table below gives the combination of ISAs, architectures, FPUs and 710 1.12 mrg floating-point ABIs for which multilibs are built for each predefined 711 1.12 mrg profile. The union of these options is considered when specifying both 712 1.12 mrg <code>aprofile</code> and <code>rmprofile</code>. 713 1.11 mrg </p> 714 1.11 mrg <table> 715 1.11 mrg <tr><td width="15%">Option</td><td width="28%">aprofile</td><td width="30%">rmprofile</td></tr> 716 1.11 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> 717 1.11 mrg <tr><td width="15%">Architectures<br><br><br><br><br><br></td><td width="28%">default architecture<br> 718 1.10 mrg <code>-march=armv7-a</code><br> 719 1.10 mrg <code>-march=armv7ve</code><br> 720 1.11 mrg <code>-march=armv8-a</code><br><br><br></td><td width="30%">default architecture<br> 721 1.10 mrg <code>-march=armv6s-m</code><br> 722 1.10 mrg <code>-march=armv7-m</code><br> 723 1.10 mrg <code>-march=armv7e-m</code><br> 724 1.10 mrg <code>-march=armv8-m.base</code><br> 725 1.10 mrg <code>-march=armv8-m.main</code><br> 726 1.11 mrg <code>-march=armv7</code></td></tr> 727 1.11 mrg <tr><td width="15%">FPUs<br><br><br><br><br></td><td width="28%">none<br> 728 1.10 mrg <code>-mfpu=vfpv3-d16</code><br> 729 1.10 mrg <code>-mfpu=neon</code><br> 730 1.10 mrg <code>-mfpu=vfpv4-d16</code><br> 731 1.10 mrg <code>-mfpu=neon-vfpv4</code><br> 732 1.11 mrg <code>-mfpu=neon-fp-armv8</code></td><td width="30%">none<br> 733 1.10 mrg <code>-mfpu=vfpv3-d16</code><br> 734 1.10 mrg <code>-mfpu=fpv4-sp-d16</code><br> 735 1.10 mrg <code>-mfpu=fpv5-sp-d16</code><br> 736 1.11 mrg <code>-mfpu=fpv5-d16</code><br></td></tr> 737 1.11 mrg <tr><td width="15%">floating-point ABIs<br><br></td><td width="28%"><code>-mfloat-abi=soft</code><br> 738 1.10 mrg <code>-mfloat-abi=softfp</code><br> 739 1.11 mrg <code>-mfloat-abi=hard</code></td><td width="30%"><code>-mfloat-abi=soft</code><br> 740 1.10 mrg <code>-mfloat-abi=softfp</code><br> 741 1.11 mrg <code>-mfloat-abi=hard</code></td></tr> 742 1.11 mrg </table> 743 1.10 mrg 744 1.11 mrg </dd> 745 1.15 mrg <dt><code>loongarch*-*-*</code></dt> 746 1.15 mrg <dd><p><var>list</var> is a comma-separated list of the following ABI identifiers: 747 1.15 mrg <code>lp64d[/base]</code> <code>lp64f[/base]</code> <code>lp64d[/base]</code>, where the 748 1.15 mrg <code>/base</code> suffix may be omitted, to enable their respective run-time 749 1.15 mrg libraries. If <var>list</var> is empty or <code>default</code>, 750 1.15 mrg or if <samp>--with-multilib-list</samp> is not specified, then the default ABI 751 1.15 mrg as specified by <samp>--with-abi</samp> or implied by <samp>--target</samp> is selected. 752 1.15 mrg </p> 753 1.15 mrg </dd> 754 1.14 mrg <dt><code>riscv*-*-*</code></dt> 755 1.12 mrg <dd><p><var>list</var> is a single ABI name. The target architecture must be either 756 1.12 mrg <code>rv32gc</code> or <code>rv64gc</code>. This will build a single multilib for the 757 1.12 mrg specified architecture and ABI pair. If <code>--with-multilib-list</code> is not 758 1.12 mrg given, then a default set of multilibs is selected based on the value of 759 1.12 mrg <samp>--target</samp>. This is usually a large set of multilibs. 760 1.12 mrg </p> 761 1.12 mrg </dd> 762 1.14 mrg <dt><code>sh*-*-*</code></dt> 763 1.11 mrg <dd><p><var>list</var> is a comma separated list of CPU names. These must be of the 764 1.1 mrg form <code>sh*</code> or <code>m*</code> (in which case they match the compiler option 765 1.1 mrg for that processor). The list should not contain any endian options - 766 1.11 mrg these are handled by <samp>--with-endian</samp>. 767 1.11 mrg </p> 768 1.11 mrg <p>If <var>list</var> is empty, then there will be no multilibs for extra 769 1.1 mrg processors. The multilib for the secondary endian remains enabled. 770 1.11 mrg </p> 771 1.11 mrg <p>As a special case, if an entry in the list starts with a <code>!</code> 772 1.11 mrg (exclamation point), then it is added to the list of excluded multilibs. 773 1.11 mrg Entries of this sort should be compatible with ‘<samp>MULTILIB_EXCLUDES</samp>’ 774 1.1 mrg (once the leading <code>!</code> has been stripped). 775 1.11 mrg </p> 776 1.11 mrg <p>If <samp>--with-multilib-list</samp> is not given, then a default set of 777 1.11 mrg multilibs is selected based on the value of <samp>--target</samp>. This is 778 1.1 mrg usually the complete set of libraries, but some targets imply a more 779 1.1 mrg specialized subset. 780 1.11 mrg </p> 781 1.11 mrg <p>Example 1: to configure a compiler for SH4A only, but supporting both 782 1.11 mrg endians, with little endian being the default: 783 1.14 mrg </p><div class="smallexample"> 784 1.14 mrg <pre class="smallexample">--with-cpu=sh4a --with-endian=little,big --with-multilib-list= 785 1.11 mrg </pre></div> 786 1.10 mrg 787 1.11 mrg <p>Example 2: to configure a compiler for both SH4A and SH4AL-DSP, but with 788 1.1 mrg only little endian SH4AL: 789 1.14 mrg </p><div class="smallexample"> 790 1.14 mrg <pre class="smallexample">--with-cpu=sh4a --with-endian=little,big \ 791 1.11 mrg --with-multilib-list=sh4al,!mb/m4al 792 1.11 mrg </pre></div> 793 1.11 mrg 794 1.11 mrg </dd> 795 1.14 mrg <dt><code>x86-64-*-linux*</code></dt> 796 1.11 mrg <dd><p><var>list</var> is a comma separated list of <code>m32</code>, <code>m64</code> and 797 1.3 mrg <code>mx32</code> to enable 32-bit, 64-bit and x32 run-time libraries, 798 1.3 mrg respectively. If <var>list</var> is empty, then there will be no multilibs 799 1.3 mrg and only the default run-time library will be enabled. 800 1.11 mrg </p> 801 1.11 mrg <p>If <samp>--with-multilib-list</samp> is not given, then only 32-bit and 802 1.11 mrg 64-bit run-time libraries will be enabled. 803 1.11 mrg </p></dd> 804 1.3 mrg </dl> 805 1.3 mrg 806 1.11 mrg </dd> 807 1.15 mrg <dt><code>--with-multilib-generator=<var>config</var></code></dt> 808 1.15 mrg <dd><p>Specify what multilibs to build. <var>config</var> is a semicolon separated list of 809 1.15 mrg values, possibly consisting of a single value. Currently only implemented 810 1.15 mrg for riscv*-*-elf*. The accepted values and meanings are given below. 811 1.15 mrg </p> 812 1.15 mrg 813 1.15 mrg <p>Every config is constructed with four components: architecture string, ABI, 814 1.15 mrg reuse rule with architecture string and reuse rule with sub-extension. 815 1.15 mrg </p> 816 1.15 mrg <p>Example 1: Add multi-lib suppport for rv32i with ilp32. 817 1.15 mrg </p><div class="smallexample"> 818 1.15 mrg <pre class="smallexample">rv32i-ilp32-- 819 1.15 mrg </pre></div> 820 1.15 mrg 821 1.15 mrg <p>Example 2: Add multi-lib suppport for rv32i with ilp32 and rv32imafd with ilp32. 822 1.15 mrg </p><div class="smallexample"> 823 1.15 mrg <pre class="smallexample">rv32i-ilp32--;rv32imafd-ilp32-- 824 1.15 mrg </pre></div> 825 1.15 mrg 826 1.15 mrg <p>Example 3: Add multi-lib suppport for rv32i with ilp32; rv32im with ilp32 and 827 1.15 mrg rv32ic with ilp32 will reuse this multi-lib set. 828 1.15 mrg </p><div class="smallexample"> 829 1.15 mrg <pre class="smallexample">rv32i-ilp32-rv32im-c 830 1.15 mrg </pre></div> 831 1.15 mrg 832 1.15 mrg <p>Example 4: Add multi-lib suppport for rv64ima with lp64; rv64imaf with lp64, 833 1.15 mrg rv64imac with lp64 and rv64imafc with lp64 will reuse this multi-lib set. 834 1.15 mrg </p><div class="smallexample"> 835 1.15 mrg <pre class="smallexample">rv64ima-lp64--f,c,fc 836 1.15 mrg </pre></div> 837 1.15 mrg 838 1.15 mrg <p><samp>--with-multilib-generator</samp> have an optional configuration argument 839 1.15 mrg <samp>--cmodel=val</samp> for code model, this option will expand with other 840 1.15 mrg config options, <var>val</var> is a comma separated list of possible code model, 841 1.15 mrg currently we support medlow and medany. 842 1.15 mrg </p> 843 1.15 mrg <p>Example 5: Add multi-lib suppport for rv64ima with lp64; rv64ima with lp64 and 844 1.15 mrg medlow code model 845 1.15 mrg </p><div class="smallexample"> 846 1.15 mrg <pre class="smallexample">rv64ima-lp64--;--cmodel=medlow 847 1.15 mrg </pre></div> 848 1.15 mrg 849 1.15 mrg <p>Example 6: Add multi-lib suppport for rv64ima with lp64; rv64ima with lp64 and 850 1.15 mrg medlow code model; rv64ima with lp64 and medany code model 851 1.15 mrg </p><div class="smallexample"> 852 1.15 mrg <pre class="smallexample">rv64ima-lp64--;--cmodel=medlow,medany 853 1.15 mrg </pre></div> 854 1.15 mrg 855 1.15 mrg </dd> 856 1.14 mrg <dt><code>--with-endian=<var>endians</var></code></dt> 857 1.11 mrg <dd><p>Specify what endians to use. 858 1.1 mrg Currently only implemented for sh*-*-*. 859 1.11 mrg </p> 860 1.11 mrg <p><var>endians</var> may be one of the following: 861 1.11 mrg </p><dl compact="compact"> 862 1.14 mrg <dt><code>big</code></dt> 863 1.11 mrg <dd><p>Use big endian exclusively. 864 1.11 mrg </p></dd> 865 1.14 mrg <dt><code>little</code></dt> 866 1.11 mrg <dd><p>Use little endian exclusively. 867 1.11 mrg </p></dd> 868 1.14 mrg <dt><code>big,little</code></dt> 869 1.11 mrg <dd><p>Use big endian by default. Provide a multilib for little endian. 870 1.11 mrg </p></dd> 871 1.14 mrg <dt><code>little,big</code></dt> 872 1.11 mrg <dd><p>Use little endian by default. Provide a multilib for big endian. 873 1.11 mrg </p></dd> 874 1.1 mrg </dl> 875 1.1 mrg 876 1.11 mrg </dd> 877 1.14 mrg <dt><code>--enable-threads</code></dt> 878 1.11 mrg <dd><p>Specify that the target 879 1.1 mrg supports threads. This affects the Objective-C compiler and runtime 880 1.11 mrg library, and exception handling for other languages like C++. 881 1.1 mrg On some systems, this is the default. 882 1.11 mrg </p> 883 1.11 mrg <p>In general, the best (and, in many cases, the only known) threading 884 1.1 mrg model available will be configured for use. Beware that on some 885 1.1 mrg systems, GCC has not been taught what threading models are generally 886 1.11 mrg available for the system. In this case, <samp>--enable-threads</samp> is an 887 1.11 mrg alias for <samp>--enable-threads=single</samp>. 888 1.11 mrg </p> 889 1.11 mrg </dd> 890 1.14 mrg <dt><code>--disable-threads</code></dt> 891 1.11 mrg <dd><p>Specify that threading support should be disabled for the system. 892 1.11 mrg This is an alias for <samp>--enable-threads=single</samp>. 893 1.11 mrg </p> 894 1.11 mrg </dd> 895 1.14 mrg <dt><code>--enable-threads=<var>lib</var></code></dt> 896 1.11 mrg <dd><p>Specify that 897 1.1 mrg <var>lib</var> is the thread support library. This affects the Objective-C 898 1.1 mrg compiler and runtime library, and exception handling for other languages 899 1.10 mrg like C++. The possibilities for <var>lib</var> are: 900 1.11 mrg </p> 901 1.11 mrg <dl compact="compact"> 902 1.14 mrg <dt><code>aix</code></dt> 903 1.11 mrg <dd><p>AIX thread support. 904 1.11 mrg </p></dd> 905 1.14 mrg <dt><code>dce</code></dt> 906 1.11 mrg <dd><p>DCE thread support. 907 1.11 mrg </p></dd> 908 1.14 mrg <dt><code>lynx</code></dt> 909 1.11 mrg <dd><p>LynxOS thread support. 910 1.11 mrg </p></dd> 911 1.14 mrg <dt><code>mipssde</code></dt> 912 1.11 mrg <dd><p>MIPS SDE thread support. 913 1.11 mrg </p></dd> 914 1.14 mrg <dt><code>no</code></dt> 915 1.11 mrg <dd><p>This is an alias for ‘<samp>single</samp>’. 916 1.11 mrg </p></dd> 917 1.14 mrg <dt><code>posix</code></dt> 918 1.11 mrg <dd><p>Generic POSIX/Unix98 thread support. 919 1.11 mrg </p></dd> 920 1.14 mrg <dt><code>rtems</code></dt> 921 1.11 mrg <dd><p>RTEMS thread support. 922 1.11 mrg </p></dd> 923 1.14 mrg <dt><code>single</code></dt> 924 1.11 mrg <dd><p>Disable thread support, should work for all platforms. 925 1.11 mrg </p></dd> 926 1.14 mrg <dt><code>tpf</code></dt> 927 1.11 mrg <dd><p>TPF thread support. 928 1.11 mrg </p></dd> 929 1.14 mrg <dt><code>vxworks</code></dt> 930 1.11 mrg <dd><p>VxWorks thread support. 931 1.11 mrg </p></dd> 932 1.14 mrg <dt><code>win32</code></dt> 933 1.11 mrg <dd><p>Microsoft Win32 API thread support. 934 1.11 mrg </p></dd> 935 1.1 mrg </dl> 936 1.1 mrg 937 1.11 mrg </dd> 938 1.14 mrg <dt><code>--enable-tls</code></dt> 939 1.11 mrg <dd><p>Specify that the target supports TLS (Thread Local Storage). Usually 940 1.1 mrg configure can correctly determine if TLS is supported. In cases where 941 1.1 mrg it guesses incorrectly, TLS can be explicitly enabled or disabled with 942 1.11 mrg <samp>--enable-tls</samp> or <samp>--disable-tls</samp>. This can happen if 943 1.1 mrg the assembler supports TLS but the C library does not, or if the 944 1.1 mrg assumptions made by the configure test are incorrect. 945 1.11 mrg </p> 946 1.11 mrg </dd> 947 1.14 mrg <dt><code>--disable-tls</code></dt> 948 1.11 mrg <dd><p>Specify that the target does not support TLS. 949 1.11 mrg This is an alias for <samp>--enable-tls=no</samp>. 950 1.11 mrg </p> 951 1.11 mrg </dd> 952 1.14 mrg <dt><code>--disable-tm-clone-registry</code></dt> 953 1.13 mrg <dd><p>Disable TM clone registry in libgcc. It is enabled in libgcc by default. 954 1.13 mrg This option helps to reduce code size for embedded targets which do 955 1.13 mrg not use transactional memory. 956 1.13 mrg </p> 957 1.13 mrg </dd> 958 1.14 mrg <dt><code>--with-cpu=<var>cpu</var></code></dt> 959 1.14 mrg <dt><code>--with-cpu-32=<var>cpu</var></code></dt> 960 1.14 mrg <dt><code>--with-cpu-64=<var>cpu</var></code></dt> 961 1.11 mrg <dd><p>Specify which cpu variant the compiler should generate code for by default. 962 1.11 mrg <var>cpu</var> will be used as the default value of the <samp>-mcpu=</samp> switch. 963 1.5 mrg This option is only supported on some targets, including ARC, ARM, i386, M68k, 964 1.11 mrg PowerPC, and SPARC. It is mandatory for ARC. The <samp>--with-cpu-32</samp> and 965 1.11 mrg <samp>--with-cpu-64</samp> options specify separate default CPUs for 966 1.13 mrg 32-bit and 64-bit modes; these options are only supported for aarch64, i386, 967 1.7 mrg x86-64, PowerPC, and SPARC. 968 1.11 mrg </p> 969 1.11 mrg </dd> 970 1.14 mrg <dt><code>--with-schedule=<var>cpu</var></code></dt> 971 1.14 mrg <dt><code>--with-arch=<var>cpu</var></code></dt> 972 1.14 mrg <dt><code>--with-arch-32=<var>cpu</var></code></dt> 973 1.14 mrg <dt><code>--with-arch-64=<var>cpu</var></code></dt> 974 1.14 mrg <dt><code>--with-tune=<var>cpu</var></code></dt> 975 1.14 mrg <dt><code>--with-tune-32=<var>cpu</var></code></dt> 976 1.14 mrg <dt><code>--with-tune-64=<var>cpu</var></code></dt> 977 1.14 mrg <dt><code>--with-abi=<var>abi</var></code></dt> 978 1.14 mrg <dt><code>--with-fpu=<var>type</var></code></dt> 979 1.14 mrg <dt><code>--with-float=<var>type</var></code></dt> 980 1.11 mrg <dd><p>These configure options provide default values for the <samp>-mschedule=</samp>, 981 1.11 mrg <samp>-march=</samp>, <samp>-mtune=</samp>, <samp>-mabi=</samp>, and <samp>-mfpu=</samp> 982 1.11 mrg options and for <samp>-mhard-float</samp> or <samp>-msoft-float</samp>. As with 983 1.11 mrg <samp>--with-cpu</samp>, which switches will be accepted and acceptable values 984 1.1 mrg of the arguments depend on the target. 985 1.11 mrg </p> 986 1.11 mrg </dd> 987 1.14 mrg <dt><code>--with-mode=<var>mode</var></code></dt> 988 1.11 mrg <dd><p>Specify if the compiler should default to <samp>-marm</samp> or <samp>-mthumb</samp>. 989 1.1 mrg This option is only supported on ARM targets. 990 1.11 mrg </p> 991 1.11 mrg </dd> 992 1.14 mrg <dt><code>--with-stack-offset=<var>num</var></code></dt> 993 1.11 mrg <dd><p>This option sets the default for the -mstack-offset=<var>num</var> option, 994 1.3 mrg and will thus generally also control the setting of this option for 995 1.3 mrg libraries. This option is only supported on Epiphany targets. 996 1.11 mrg </p> 997 1.11 mrg </dd> 998 1.14 mrg <dt><code>--with-fpmath=<var>isa</var></code></dt> 999 1.11 mrg <dd><p>This options sets <samp>-mfpmath=sse</samp> by default and specifies the default 1000 1.11 mrg ISA for floating-point arithmetics. You can select either ‘<samp>sse</samp>’ which 1001 1.11 mrg enables <samp>-msse2</samp> or ‘<samp>avx</samp>’ which enables <samp>-mavx</samp> by default. 1002 1.3 mrg This option is only supported on i386 and x86-64 targets. 1003 1.11 mrg </p> 1004 1.11 mrg </dd> 1005 1.14 mrg <dt><code>--with-fp-32=<var>mode</var></code></dt> 1006 1.11 mrg <dd><p>On MIPS targets, set the default value for the <samp>-mfp</samp> option when using 1007 1.5 mrg the o32 ABI. The possibilities for <var>mode</var> are: 1008 1.11 mrg </p><dl compact="compact"> 1009 1.14 mrg <dt><code>32</code></dt> 1010 1.11 mrg <dd><p>Use the o32 FP32 ABI extension, as with the <samp>-mfp32</samp> command-line 1011 1.11 mrg option. 1012 1.11 mrg </p></dd> 1013 1.14 mrg <dt><code>xx</code></dt> 1014 1.11 mrg <dd><p>Use the o32 FPXX ABI extension, as with the <samp>-mfpxx</samp> command-line 1015 1.11 mrg option. 1016 1.11 mrg </p></dd> 1017 1.14 mrg <dt><code>64</code></dt> 1018 1.11 mrg <dd><p>Use the o32 FP64 ABI extension, as with the <samp>-mfp64</samp> command-line 1019 1.11 mrg option. 1020 1.11 mrg </p></dd> 1021 1.5 mrg </dl> 1022 1.11 mrg <p>In the absence of this configuration option the default is to use the o32 1023 1.5 mrg FP32 ABI extension. 1024 1.11 mrg </p> 1025 1.11 mrg </dd> 1026 1.14 mrg <dt><code>--with-odd-spreg-32</code></dt> 1027 1.11 mrg <dd><p>On MIPS targets, set the <samp>-modd-spreg</samp> option by default when using 1028 1.5 mrg the o32 ABI. 1029 1.11 mrg </p> 1030 1.11 mrg </dd> 1031 1.14 mrg <dt><code>--without-odd-spreg-32</code></dt> 1032 1.11 mrg <dd><p>On MIPS targets, set the <samp>-mno-odd-spreg</samp> option by default when using 1033 1.5 mrg the o32 ABI. This is normally used in conjunction with 1034 1.11 mrg <samp>--with-fp-32=64</samp> in order to target the o32 FP64A ABI extension. 1035 1.11 mrg </p> 1036 1.11 mrg </dd> 1037 1.14 mrg <dt><code>--with-nan=<var>encoding</var></code></dt> 1038 1.11 mrg <dd><p>On MIPS targets, set the default encoding convention to use for the 1039 1.5 mrg special not-a-number (NaN) IEEE 754 floating-point data. The 1040 1.5 mrg possibilities for <var>encoding</var> are: 1041 1.11 mrg </p><dl compact="compact"> 1042 1.14 mrg <dt><code>legacy</code></dt> 1043 1.11 mrg <dd><p>Use the legacy encoding, as with the <samp>-mnan=legacy</samp> command-line 1044 1.11 mrg option. 1045 1.11 mrg </p></dd> 1046 1.14 mrg <dt><code>2008</code></dt> 1047 1.11 mrg <dd><p>Use the 754-2008 encoding, as with the <samp>-mnan=2008</samp> command-line 1048 1.11 mrg option. 1049 1.11 mrg </p></dd> 1050 1.5 mrg </dl> 1051 1.11 mrg <p>To use this configuration option you must have an assembler version 1052 1.11 mrg installed that supports the <samp>-mnan=</samp> command-line option too. 1053 1.5 mrg In the absence of this configuration option the default convention is 1054 1.11 mrg the legacy encoding, as when neither of the <samp>-mnan=2008</samp> and 1055 1.11 mrg <samp>-mnan=legacy</samp> command-line options has been used. 1056 1.11 mrg </p> 1057 1.11 mrg </dd> 1058 1.14 mrg <dt><code>--with-divide=<var>type</var></code></dt> 1059 1.11 mrg <dd><p>Specify how the compiler should generate code for checking for 1060 1.11 mrg division by zero. This option is only supported on the MIPS target. 1061 1.1 mrg The possibilities for <var>type</var> are: 1062 1.11 mrg </p><dl compact="compact"> 1063 1.14 mrg <dt><code>traps</code></dt> 1064 1.11 mrg <dd><p>Division by zero checks use conditional traps (this is the default on 1065 1.11 mrg systems that support conditional traps). 1066 1.11 mrg </p></dd> 1067 1.14 mrg <dt><code>breaks</code></dt> 1068 1.11 mrg <dd><p>Division by zero checks use the break instruction. 1069 1.11 mrg </p></dd> 1070 1.1 mrg </dl> 1071 1.1 mrg 1072 1.11 mrg 1073 1.11 mrg </dd> 1074 1.14 mrg <dt><code>--with-llsc</code></dt> 1075 1.11 mrg <dd><p>On MIPS targets, make <samp>-mllsc</samp> the default when no 1076 1.11 mrg <samp>-mno-llsc</samp> option is passed. This is the default for 1077 1.1 mrg Linux-based targets, as the kernel will emulate them if the ISA does 1078 1.1 mrg not provide them. 1079 1.11 mrg </p> 1080 1.11 mrg </dd> 1081 1.14 mrg <dt><code>--without-llsc</code></dt> 1082 1.11 mrg <dd><p>On MIPS targets, make <samp>-mno-llsc</samp> the default when no 1083 1.11 mrg <samp>-mllsc</samp> option is passed. 1084 1.11 mrg </p> 1085 1.11 mrg </dd> 1086 1.14 mrg <dt><code>--with-synci</code></dt> 1087 1.11 mrg <dd><p>On MIPS targets, make <samp>-msynci</samp> the default when no 1088 1.11 mrg <samp>-mno-synci</samp> option is passed. 1089 1.11 mrg </p> 1090 1.11 mrg </dd> 1091 1.14 mrg <dt><code>--without-synci</code></dt> 1092 1.11 mrg <dd><p>On MIPS targets, make <samp>-mno-synci</samp> the default when no 1093 1.11 mrg <samp>-msynci</samp> option is passed. This is the default. 1094 1.11 mrg </p> 1095 1.11 mrg </dd> 1096 1.14 mrg <dt><code>--with-lxc1-sxc1</code></dt> 1097 1.11 mrg <dd><p>On MIPS targets, make <samp>-mlxc1-sxc1</samp> the default when no 1098 1.11 mrg <samp>-mno-lxc1-sxc1</samp> option is passed. This is the default. 1099 1.11 mrg </p> 1100 1.11 mrg </dd> 1101 1.14 mrg <dt><code>--without-lxc1-sxc1</code></dt> 1102 1.11 mrg <dd><p>On MIPS targets, make <samp>-mno-lxc1-sxc1</samp> the default when no 1103 1.11 mrg <samp>-mlxc1-sxc1</samp> option is passed. The indexed load/store 1104 1.10 mrg instructions are not directly a problem but can lead to unexpected 1105 1.10 mrg behaviour when deployed in an application intended for a 32-bit address 1106 1.10 mrg space but run on a 64-bit processor. The issue is seen because all 1107 1.10 mrg known MIPS 64-bit Linux kernels execute o32 and n32 applications 1108 1.10 mrg with 64-bit addressing enabled which affects the overflow behaviour 1109 1.10 mrg of the indexed addressing mode. GCC will assume that ordinary 1110 1.10 mrg 32-bit arithmetic overflow behaviour is the same whether performed 1111 1.10 mrg as an <code>addu</code> instruction or as part of the address calculation 1112 1.10 mrg in <code>lwxc1</code> type instructions. This assumption holds true in a 1113 1.10 mrg pure 32-bit environment and can hold true in a 64-bit environment if 1114 1.10 mrg the address space is accurately set to be 32-bit for o32 and n32. 1115 1.11 mrg </p> 1116 1.11 mrg </dd> 1117 1.14 mrg <dt><code>--with-madd4</code></dt> 1118 1.11 mrg <dd><p>On MIPS targets, make <samp>-mmadd4</samp> the default when no 1119 1.11 mrg <samp>-mno-madd4</samp> option is passed. This is the default. 1120 1.11 mrg </p> 1121 1.11 mrg </dd> 1122 1.14 mrg <dt><code>--without-madd4</code></dt> 1123 1.11 mrg <dd><p>On MIPS targets, make <samp>-mno-madd4</samp> the default when no 1124 1.11 mrg <samp>-mmadd4</samp> option is passed. The <code>madd4</code> instruction 1125 1.10 mrg family can be problematic when targeting a combination of cores that 1126 1.10 mrg implement these instructions differently. There are two known cores 1127 1.10 mrg that implement these as fused operations instead of unfused (where 1128 1.10 mrg unfused is normally expected). Disabling these instructions is the 1129 1.10 mrg only way to ensure compatible code is generated; this will incur 1130 1.10 mrg a performance penalty. 1131 1.11 mrg </p> 1132 1.11 mrg </dd> 1133 1.14 mrg <dt><code>--with-mips-plt</code></dt> 1134 1.11 mrg <dd><p>On MIPS targets, make use of copy relocations and PLTs. 1135 1.1 mrg These features are extensions to the traditional 1136 1.1 mrg SVR4-based MIPS ABIs and require support from GNU binutils 1137 1.1 mrg and the runtime C library. 1138 1.11 mrg </p> 1139 1.11 mrg </dd> 1140 1.14 mrg <dt><code>--with-stack-clash-protection-guard-size=<var>size</var></code></dt> 1141 1.12 mrg <dd><p>On certain targets this option sets the default stack clash protection guard 1142 1.12 mrg size as a power of two in bytes. On AArch64 <var>size</var> is required to be either 1143 1.12 mrg 12 (4KB) or 16 (64KB). 1144 1.12 mrg </p> 1145 1.12 mrg </dd> 1146 1.15 mrg <dt><code>--with-isa-spec=<var>ISA-spec-string</var></code></dt> 1147 1.15 mrg <dd><p>On RISC-V targets specify the default version of the RISC-V Unprivileged 1148 1.15 mrg (formerly User-Level) ISA specification to produce code conforming to. 1149 1.15 mrg The possibilities for <var>ISA-spec-string</var> are: 1150 1.15 mrg </p><dl compact="compact"> 1151 1.15 mrg <dt><code>2.2</code></dt> 1152 1.15 mrg <dd><p>Produce code conforming to version 2.2. 1153 1.15 mrg </p></dd> 1154 1.15 mrg <dt><code>20190608</code></dt> 1155 1.15 mrg <dd><p>Produce code conforming to version 20190608. 1156 1.15 mrg </p></dd> 1157 1.15 mrg <dt><code>20191213</code></dt> 1158 1.15 mrg <dd><p>Produce code conforming to version 20191213. 1159 1.15 mrg </p></dd> 1160 1.15 mrg </dl> 1161 1.15 mrg <p>In the absence of this configuration option the default version is 20191213. 1162 1.15 mrg </p> 1163 1.15 mrg </dd> 1164 1.14 mrg <dt><code>--enable-__cxa_atexit</code></dt> 1165 1.11 mrg <dd><p>Define if you want to use __cxa_atexit, rather than atexit, to 1166 1.11 mrg register C++ destructors for local statics and global objects. 1167 1.1 mrg This is essential for fully standards-compliant handling of 1168 1.1 mrg destructors, but requires __cxa_atexit in libc. This option is currently 1169 1.1 mrg only available on systems with GNU libc. When enabled, this will cause 1170 1.11 mrg <samp>-fuse-cxa-atexit</samp> to be passed by default. 1171 1.11 mrg </p> 1172 1.11 mrg </dd> 1173 1.14 mrg <dt><code>--enable-gnu-indirect-function</code></dt> 1174 1.11 mrg <dd><p>Define if you want to enable the <code>ifunc</code> attribute. This option is 1175 1.3 mrg currently only available on systems with GNU libc on certain targets. 1176 1.11 mrg </p> 1177 1.11 mrg </dd> 1178 1.14 mrg <dt><code>--enable-target-optspace</code></dt> 1179 1.11 mrg <dd><p>Specify that target 1180 1.11 mrg libraries should be optimized for code space instead of code speed. 1181 1.1 mrg This is the default for the m32r platform. 1182 1.11 mrg </p> 1183 1.11 mrg </dd> 1184 1.14 mrg <dt><code>--with-cpp-install-dir=<var>dirname</var></code></dt> 1185 1.11 mrg <dd><p>Specify that the user visible <code>cpp</code> program should be installed 1186 1.11 mrg in <samp><var>prefix</var>/<var>dirname</var>/cpp</samp>, in addition to <var>bindir</var>. 1187 1.11 mrg </p> 1188 1.11 mrg </dd> 1189 1.14 mrg <dt><code>--enable-comdat</code></dt> 1190 1.11 mrg <dd><p>Enable COMDAT group support. This is primarily used to override the 1191 1.1 mrg automatically detected value. 1192 1.11 mrg </p> 1193 1.11 mrg </dd> 1194 1.14 mrg <dt><code>--enable-initfini-array</code></dt> 1195 1.11 mrg <dd><p>Force the use of sections <code>.init_array</code> and <code>.fini_array</code> 1196 1.1 mrg (instead of <code>.init</code> and <code>.fini</code>) for constructors and 1197 1.11 mrg destructors. Option <samp>--disable-initfini-array</samp> has the 1198 1.1 mrg opposite effect. If neither option is specified, the configure script 1199 1.1 mrg will try to guess whether the <code>.init_array</code> and 1200 1.1 mrg <code>.fini_array</code> sections are supported and, if they are, use them. 1201 1.11 mrg </p> 1202 1.11 mrg </dd> 1203 1.14 mrg <dt><code>--enable-link-mutex</code></dt> 1204 1.11 mrg <dd><p>When building GCC, use a mutex to avoid linking the compilers for 1205 1.5 mrg multiple languages at the same time, to avoid thrashing on build 1206 1.5 mrg systems with limited free memory. The default is not to use such a mutex. 1207 1.11 mrg </p> 1208 1.11 mrg </dd> 1209 1.15 mrg <dt><code>--enable-link-serialization</code></dt> 1210 1.15 mrg <dd><p>When building GCC, use make dependencies to serialize linking the compilers for 1211 1.15 mrg multiple languages, to avoid thrashing on build 1212 1.15 mrg systems with limited free memory. The default is not to add such 1213 1.15 mrg dependencies and thus with parallel make potentially link different 1214 1.15 mrg compilers concurrently. If the argument is a positive integer, allow 1215 1.15 mrg that number of concurrent link processes for the large binaries. 1216 1.15 mrg </p> 1217 1.15 mrg </dd> 1218 1.14 mrg <dt><code>--enable-maintainer-mode</code></dt> 1219 1.11 mrg <dd><p>The build rules that regenerate the Autoconf and Automake output files as 1220 1.11 mrg well as the GCC master message catalog <samp>gcc.pot</samp> are normally 1221 1.1 mrg disabled. This is because it can only be rebuilt if the complete source 1222 1.1 mrg tree is present. If you have changed the sources and want to rebuild the 1223 1.11 mrg catalog, configuring with <samp>--enable-maintainer-mode</samp> will enable 1224 1.1 mrg this. Note that you need a recent version of the <code>gettext</code> tools 1225 1.1 mrg to do so. 1226 1.11 mrg </p> 1227 1.11 mrg </dd> 1228 1.14 mrg <dt><code>--disable-bootstrap</code></dt> 1229 1.11 mrg <dd><p>For a native build, the default configuration is to perform 1230 1.11 mrg a 3-stage bootstrap of the compiler when ‘<samp>make</samp>’ is invoked, 1231 1.1 mrg testing that GCC can compile itself correctly. If you want to disable 1232 1.11 mrg this process, you can configure with <samp>--disable-bootstrap</samp>. 1233 1.11 mrg </p> 1234 1.11 mrg </dd> 1235 1.14 mrg <dt><code>--enable-bootstrap</code></dt> 1236 1.11 mrg <dd><p>In special cases, you may want to perform a 3-stage build 1237 1.11 mrg even if the target and host triplets are different. 1238 1.1 mrg This is possible when the host can run code compiled for 1239 1.11 mrg the target (e.g. host is i686-linux, target is i486-linux). 1240 1.1 mrg Starting from GCC 4.2, to do this you have to configure explicitly 1241 1.11 mrg with <samp>--enable-bootstrap</samp>. 1242 1.11 mrg </p> 1243 1.11 mrg </dd> 1244 1.14 mrg <dt><code>--enable-generated-files-in-srcdir</code></dt> 1245 1.11 mrg <dd><p>Neither the .c and .h files that are generated from Bison and flex nor the 1246 1.1 mrg info manuals and man pages that are built from the .texi files are present 1247 1.11 mrg in the repository development tree. When building GCC from that development tree, 1248 1.1 mrg or from one of our snapshots, those generated files are placed in your 1249 1.1 mrg build directory, which allows for the source to be in a readonly 1250 1.1 mrg directory. 1251 1.11 mrg </p> 1252 1.11 mrg <p>If you configure with <samp>--enable-generated-files-in-srcdir</samp> then those 1253 1.1 mrg generated files will go into the source directory. This is mainly intended 1254 1.1 mrg for generating release or prerelease tarballs of the GCC sources, since it 1255 1.1 mrg is not a requirement that the users of source releases to have flex, Bison, 1256 1.1 mrg or makeinfo. 1257 1.11 mrg </p> 1258 1.11 mrg </dd> 1259 1.14 mrg <dt><code>--enable-version-specific-runtime-libs</code></dt> 1260 1.11 mrg <dd><p>Specify 1261 1.1 mrg that runtime libraries should be installed in the compiler specific 1262 1.11 mrg subdirectory (<samp><var>libdir</var>/gcc</samp>) rather than the usual places. In 1263 1.11 mrg addition, ‘<samp>libstdc++</samp>’’s include files will be installed into 1264 1.1 mrg <samp><var>libdir</var></samp> unless you overruled it by using 1265 1.11 mrg <samp>--with-gxx-include-dir=<var>dirname</var></samp>. Using this option is 1266 1.1 mrg particularly useful if you intend to use several versions of GCC in 1267 1.13 mrg parallel. The default is ‘<samp>yes</samp>’ for ‘<samp>libada</samp>’, and ‘<samp>no</samp>’ for 1268 1.13 mrg the remaining libraries. 1269 1.11 mrg </p> 1270 1.11 mrg </dd> 1271 1.14 mrg <dt><code><a name="WithAixSoname"></a>--with-aix-soname=‘<samp>aix</samp>’, ‘<samp>svr4</samp>’ or ‘<samp>both</samp>’</code></dt> 1272 1.11 mrg <dd><p>Traditional AIX shared library versioning (versioned <code>Shared Object</code> 1273 1.5 mrg files as members of unversioned <code>Archive Library</code> files named 1274 1.11 mrg ‘<samp>lib.a</samp>’) causes numerous headaches for package managers. However, 1275 1.5 mrg <code>Import Files</code> as members of <code>Archive Library</code> files allow for 1276 1.5 mrg <strong>filename-based versioning</strong> of shared libraries as seen on Linux/SVR4, 1277 1.11 mrg where this is called the "SONAME". But as they prevent static linking, 1278 1.5 mrg <code>Import Files</code> may be used with <code>Runtime Linking</code> only, where the 1279 1.11 mrg linker does search for ‘<samp>libNAME.so</samp>’ before ‘<samp>libNAME.a</samp>’ library 1280 1.11 mrg filenames with the ‘<samp>-lNAME</samp>’ linker flag. 1281 1.11 mrg </p> 1282 1.14 mrg <a name="AixLdCommand"></a><p>For detailed information please refer to the AIX 1283 1.11 mrg <a href="https://www.ibm.com/support/knowledgecenter/search/%22the%20ld%20command%2C%20also%20called%20the%20linkage%20editor%20or%20binder%22">ld 1284 1.11 mrg Command</a> reference. 1285 1.11 mrg </p> 1286 1.11 mrg <p>As long as shared library creation is enabled, upon: 1287 1.11 mrg </p><dl compact="compact"> 1288 1.14 mrg <dt><code>--with-aix-soname=aix</code></dt> 1289 1.14 mrg <dt><code>--with-aix-soname=both</code></dt> 1290 1.11 mrg <dd><p>A (traditional AIX) <code>Shared Archive Library</code> file is created: 1291 1.11 mrg </p><ul> 1292 1.11 mrg <li> using the ‘<samp>libNAME.a</samp>’ filename scheme 1293 1.11 mrg </li><li> with the <code>Shared Object</code> file as archive member named 1294 1.11 mrg ‘<samp>libNAME.so.V</samp>’ (except for ‘<samp>libgcc_s</samp>’, where the <code>Shared 1295 1.11 mrg Object</code> file is named ‘<samp>shr.o</samp>’ for backwards compatibility), which 1296 1.11 mrg <ul class="no-bullet"> 1297 1.11 mrg <li>- is used for runtime loading from inside the ‘<samp>libNAME.a</samp>’ file 1298 1.11 mrg </li><li>- is used for dynamic loading via 1299 1.11 mrg <code>dlopen("libNAME.a(libNAME.so.V)", RTLD_MEMBER)</code> 1300 1.11 mrg </li><li>- is used for shared linking 1301 1.11 mrg </li><li>- is used for static linking, so no separate <code>Static Archive 1302 1.5 mrg Library</code> file is needed 1303 1.11 mrg </li></ul> 1304 1.11 mrg </li></ul> 1305 1.11 mrg </dd> 1306 1.14 mrg <dt><code>--with-aix-soname=both</code></dt> 1307 1.14 mrg <dt><code>--with-aix-soname=svr4</code></dt> 1308 1.11 mrg <dd><p>A (second) <code>Shared Archive Library</code> file is created: 1309 1.11 mrg </p><ul> 1310 1.11 mrg <li> using the ‘<samp>libNAME.so.V</samp>’ filename scheme 1311 1.11 mrg </li><li> with the <code>Shared Object</code> file as archive member named 1312 1.11 mrg ‘<samp>shr.o</samp>’, which 1313 1.11 mrg <ul class="no-bullet"> 1314 1.11 mrg <li>- is created with the <code>-G linker flag</code> 1315 1.11 mrg </li><li>- has the <code>F_LOADONLY</code> flag set 1316 1.11 mrg </li><li>- is used for runtime loading from inside the ‘<samp>libNAME.so.V</samp>’ file 1317 1.11 mrg </li><li>- is used for dynamic loading via <code>dlopen("libNAME.so.V(shr.o)", 1318 1.5 mrg RTLD_MEMBER)</code> 1319 1.11 mrg </li></ul> 1320 1.11 mrg </li><li> with the <code>Import File</code> as archive member named ‘<samp>shr.imp</samp>’, 1321 1.5 mrg which 1322 1.11 mrg <ul class="no-bullet"> 1323 1.11 mrg <li>- refers to ‘<samp>libNAME.so.V(shr.o)</samp>’ as the "SONAME", to be recorded 1324 1.5 mrg in the <code>Loader Section</code> of subsequent binaries 1325 1.11 mrg </li><li>- indicates whether ‘<samp>libNAME.so.V(shr.o)</samp>’ is 32 or 64 bit 1326 1.11 mrg </li><li>- lists all the public symbols exported by ‘<samp>lib.so.V(shr.o)</samp>’, 1327 1.11 mrg eventually decorated with the <code>‘<samp>weak</samp>’ Keyword</code> 1328 1.11 mrg </li><li>- is necessary for shared linking against ‘<samp>lib.so.V(shr.o)</samp>’ 1329 1.11 mrg </li></ul> 1330 1.11 mrg </li></ul> 1331 1.11 mrg <p>A symbolic link using the ‘<samp>libNAME.so</samp>’ filename scheme is created: 1332 1.11 mrg </p><ul> 1333 1.11 mrg <li> pointing to the ‘<samp>libNAME.so.V</samp>’ <code>Shared Archive Library</code> file 1334 1.11 mrg </li><li> to permit the <code>ld Command</code> to find ‘<samp>lib.so.V(shr.imp)</samp>’ via 1335 1.11 mrg the ‘<samp>-lNAME</samp>’ argument (requires <code>Runtime Linking</code> to be enabled) 1336 1.11 mrg </li><li> to permit dynamic loading of ‘<samp>lib.so.V(shr.o)</samp>’ without the need 1337 1.11 mrg to specify the version number via <code>dlopen("libNAME.so(shr.o)", 1338 1.5 mrg RTLD_MEMBER)</code> 1339 1.11 mrg </li></ul> 1340 1.11 mrg </dd> 1341 1.11 mrg </dl> 1342 1.5 mrg 1343 1.11 mrg <p>As long as static library creation is enabled, upon: 1344 1.11 mrg </p><dl compact="compact"> 1345 1.14 mrg <dt><code>--with-aix-soname=svr4</code></dt> 1346 1.11 mrg <dd><p>A <code>Static Archive Library</code> is created: 1347 1.11 mrg </p><ul> 1348 1.11 mrg <li> using the ‘<samp>libNAME.a</samp>’ filename scheme 1349 1.11 mrg </li><li> with all the <code>Static Object</code> files as archive members, which 1350 1.11 mrg <ul class="no-bullet"> 1351 1.11 mrg <li>- are used for static linking 1352 1.11 mrg </li></ul> 1353 1.11 mrg </li></ul> 1354 1.11 mrg </dd> 1355 1.11 mrg </dl> 1356 1.5 mrg 1357 1.11 mrg <p>While the aix-soname=‘<samp>svr4</samp>’ option does not create <code>Shared Object</code> 1358 1.5 mrg files as members of unversioned <code>Archive Library</code> files any more, package 1359 1.5 mrg managers still are responsible to 1360 1.5 mrg <a href="./specific.html#TransferAixShobj">transfer</a> <code>Shared Object</code> files 1361 1.5 mrg found as member of a previously installed unversioned <code>Archive Library</code> 1362 1.5 mrg file into the newly installed <code>Archive Library</code> file with the same 1363 1.5 mrg filename. 1364 1.11 mrg </p> 1365 1.11 mrg <p><em>WARNING:</em> Creating <code>Shared Object</code> files with <code>Runtime Linking</code> 1366 1.5 mrg enabled may bloat the TOC, eventually leading to <code>TOC overflow</code> errors, 1367 1.11 mrg requiring the use of either the <samp>-Wl,-bbigtoc</samp> linker flag (seen to 1368 1.5 mrg break with the <code>GDB</code> debugger) or some of the TOC-related compiler flags, 1369 1.5 mrg see “RS/6000 and PowerPC Options” in the main manual. 1370 1.11 mrg </p> 1371 1.11 mrg <p><samp>--with-aix-soname</samp> is currently supported by ‘<samp>libgcc_s</samp>’ only, so 1372 1.5 mrg this option is still experimental and not for normal use yet. 1373 1.11 mrg </p> 1374 1.11 mrg <p>Default is the traditional behavior <samp>--with-aix-soname=‘<samp>aix</samp>’</samp>. 1375 1.11 mrg </p> 1376 1.11 mrg </dd> 1377 1.14 mrg <dt><code>--enable-languages=<var>lang1</var>,<var>lang2</var>,…</code></dt> 1378 1.11 mrg <dd><p>Specify that only a particular subset of compilers and 1379 1.1 mrg their runtime libraries should be built. For a list of valid values for 1380 1.1 mrg <var>langN</var> you can issue the following command in the 1381 1.11 mrg <samp>gcc</samp> directory of your GCC source tree:<br> 1382 1.14 mrg </p><div class="smallexample"> 1383 1.14 mrg <pre class="smallexample">grep ^language= */config-lang.in 1384 1.11 mrg </pre></div> 1385 1.11 mrg <p>Currently, you can use any of the following: 1386 1.12 mrg <code>all</code>, <code>default</code>, <code>ada</code>, <code>c</code>, <code>c++</code>, <code>d</code>, 1387 1.12 mrg <code>fortran</code>, <code>go</code>, <code>jit</code>, <code>lto</code>, <code>objc</code>, <code>obj-c++</code>. 1388 1.11 mrg Building the Ada compiler has special requirements, see below. 1389 1.11 mrg If you do not pass this flag, or specify the option <code>default</code>, then the 1390 1.11 mrg default languages available in the <samp>gcc</samp> sub-tree will be configured. 1391 1.12 mrg Ada, D, Go, Jit, and Objective-C++ are not default languages. LTO is not a 1392 1.11 mrg default language, but is built by default because <samp>--enable-lto</samp> is 1393 1.11 mrg enabled by default. The other languages are default languages. If 1394 1.11 mrg <code>all</code> is specified, then all available languages are built. An 1395 1.11 mrg exception is <code>jit</code> language, which requires 1396 1.11 mrg <samp>--enable-host-shared</samp> to be included with <code>all</code>. 1397 1.11 mrg </p> 1398 1.11 mrg </dd> 1399 1.14 mrg <dt><code>--enable-stage1-languages=<var>lang1</var>,<var>lang2</var>,…</code></dt> 1400 1.11 mrg <dd><p>Specify that a particular subset of compilers and their runtime 1401 1.1 mrg libraries should be built with the system C compiler during stage 1 of 1402 1.1 mrg the bootstrap process, rather than only in later stages with the 1403 1.1 mrg bootstrapped C compiler. The list of valid values is the same as for 1404 1.11 mrg <samp>--enable-languages</samp>, and the option <code>all</code> will select all 1405 1.11 mrg of the languages enabled by <samp>--enable-languages</samp>. This option is 1406 1.1 mrg primarily useful for GCC development; for instance, when a development 1407 1.1 mrg version of the compiler cannot bootstrap due to compiler bugs, or when 1408 1.1 mrg one is debugging front ends other than the C front end. When this 1409 1.1 mrg option is used, one can then build the target libraries for the 1410 1.11 mrg specified languages with the stage-1 compiler by using <code>make 1411 1.11 mrg stage1-bubble all-target</code>, or run the testsuite on the stage-1 compiler 1412 1.11 mrg for the specified languages using <code>make stage1-start check-gcc</code>. 1413 1.11 mrg </p> 1414 1.11 mrg </dd> 1415 1.14 mrg <dt><code>--disable-libada</code></dt> 1416 1.11 mrg <dd><p>Specify that the run-time libraries and tools used by GNAT should not 1417 1.1 mrg be built. This can be useful for debugging, or for compatibility with 1418 1.1 mrg previous Ada build procedures, when it was required to explicitly 1419 1.11 mrg do a ‘<samp>make -C gcc gnatlib_and_tools</samp>’. 1420 1.11 mrg </p> 1421 1.11 mrg </dd> 1422 1.14 mrg <dt><code>--disable-libsanitizer</code></dt> 1423 1.11 mrg <dd><p>Specify that the run-time libraries for the various sanitizers should 1424 1.5 mrg not be built. 1425 1.11 mrg </p> 1426 1.11 mrg </dd> 1427 1.14 mrg <dt><code>--disable-libssp</code></dt> 1428 1.11 mrg <dd><p>Specify that the run-time libraries for stack smashing protection 1429 1.11 mrg should not be built or linked against. On many targets library support 1430 1.11 mrg is provided by the C library instead. 1431 1.11 mrg </p> 1432 1.11 mrg </dd> 1433 1.14 mrg <dt><code>--disable-libquadmath</code></dt> 1434 1.11 mrg <dd><p>Specify that the GCC quad-precision math library should not be built. 1435 1.3 mrg On some systems, the library is required to be linkable when building 1436 1.11 mrg the Fortran front end, unless <samp>--disable-libquadmath-support</samp> 1437 1.3 mrg is used. 1438 1.11 mrg </p> 1439 1.11 mrg </dd> 1440 1.14 mrg <dt><code>--disable-libquadmath-support</code></dt> 1441 1.11 mrg <dd><p>Specify that the Fortran front end and <code>libgfortran</code> do not add 1442 1.3 mrg support for <code>libquadmath</code> on systems supporting it. 1443 1.11 mrg </p> 1444 1.11 mrg </dd> 1445 1.14 mrg <dt><code>--disable-libgomp</code></dt> 1446 1.11 mrg <dd><p>Specify that the GNU Offloading and Multi Processing Runtime Library 1447 1.5 mrg should not be built. 1448 1.11 mrg </p> 1449 1.11 mrg </dd> 1450 1.14 mrg <dt><code>--disable-libvtv</code></dt> 1451 1.11 mrg <dd><p>Specify that the run-time libraries used by vtable verification 1452 1.5 mrg should not be built. 1453 1.11 mrg </p> 1454 1.11 mrg </dd> 1455 1.14 mrg <dt><code>--with-dwarf2</code></dt> 1456 1.11 mrg <dd><p>Specify that the compiler should 1457 1.1 mrg use DWARF 2 debugging information as the default. 1458 1.11 mrg </p> 1459 1.11 mrg </dd> 1460 1.14 mrg <dt><code>--with-advance-toolchain=<var>at</var></code></dt> 1461 1.11 mrg <dd><p>On 64-bit PowerPC Linux systems, configure the compiler to use the 1462 1.7 mrg header files, library files, and the dynamic linker from the Advance 1463 1.7 mrg Toolchain release <var>at</var> instead of the default versions that are 1464 1.7 mrg provided by the Linux distribution. In general, this option is 1465 1.7 mrg intended for the developers of GCC, and it is not intended for general 1466 1.7 mrg use. 1467 1.11 mrg </p> 1468 1.11 mrg </dd> 1469 1.14 mrg <dt><code>--enable-targets=all</code></dt> 1470 1.14 mrg <dt><code>--enable-targets=<var>target_list</var></code></dt> 1471 1.11 mrg <dd><p>Some GCC targets, e.g. powerpc64-linux, build bi-arch compilers. 1472 1.1 mrg These are compilers that are able to generate either 64-bit or 32-bit 1473 1.11 mrg code. Typically, the corresponding 32-bit target, e.g. 1474 1.1 mrg powerpc-linux for powerpc64-linux, only generates 32-bit code. This 1475 1.1 mrg option enables the 32-bit target to be a bi-arch compiler, which is 1476 1.1 mrg useful when you want a bi-arch compiler that defaults to 32-bit, and 1477 1.11 mrg you are building a bi-arch or multi-arch binutils in a combined tree. 1478 1.1 mrg On mips-linux, this will build a tri-arch compiler (ABI o32/n32/64), 1479 1.11 mrg defaulted to o32. 1480 1.3 mrg Currently, this option only affects sparc-linux, powerpc-linux, x86-linux, 1481 1.3 mrg mips-linux and s390-linux. 1482 1.11 mrg </p> 1483 1.11 mrg </dd> 1484 1.14 mrg <dt><code>--enable-default-pie</code></dt> 1485 1.11 mrg <dd><p>Turn on <samp>-fPIE</samp> and <samp>-pie</samp> by default. 1486 1.11 mrg </p> 1487 1.11 mrg </dd> 1488 1.14 mrg <dt><code>--enable-secureplt</code></dt> 1489 1.11 mrg <dd><p>This option enables <samp>-msecure-plt</samp> by default for powerpc-linux. 1490 1.1 mrg See “RS/6000 and PowerPC Options” in the main manual 1491 1.11 mrg </p> 1492 1.11 mrg </dd> 1493 1.14 mrg <dt><code>--enable-default-ssp</code></dt> 1494 1.11 mrg <dd><p>Turn on <samp>-fstack-protector-strong</samp> by default. 1495 1.11 mrg </p> 1496 1.11 mrg </dd> 1497 1.14 mrg <dt><code>--enable-cld</code></dt> 1498 1.11 mrg <dd><p>This option enables <samp>-mcld</samp> by default for 32-bit x86 targets. 1499 1.1 mrg See “i386 and x86-64 Options” in the main manual 1500 1.11 mrg </p> 1501 1.11 mrg </dd> 1502 1.14 mrg <dt><code>--enable-large-address-aware</code></dt> 1503 1.12 mrg <dd><p>The <samp>--enable-large-address-aware</samp> option arranges for MinGW 1504 1.12 mrg executables to be linked using the <samp>--large-address-aware</samp> 1505 1.12 mrg option, that enables the use of more than 2GB of memory. If GCC is 1506 1.12 mrg configured with this option, its effects can be reversed by passing the 1507 1.12 mrg <samp>-Wl,--disable-large-address-aware</samp> option to the so-configured 1508 1.12 mrg compiler driver. 1509 1.12 mrg </p> 1510 1.12 mrg </dd> 1511 1.14 mrg <dt><code>--enable-win32-registry</code></dt> 1512 1.14 mrg <dt><code>--enable-win32-registry=<var>key</var></code></dt> 1513 1.14 mrg <dt><code>--disable-win32-registry</code></dt> 1514 1.11 mrg <dd><p>The <samp>--enable-win32-registry</samp> option enables Microsoft Windows-hosted GCC 1515 1.1 mrg to look up installations paths in the registry using the following key: 1516 1.11 mrg </p> 1517 1.14 mrg <div class="smallexample"> 1518 1.14 mrg <pre class="smallexample"><code>HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\<var>key</var></code> 1519 1.11 mrg </pre></div> 1520 1.1 mrg 1521 1.11 mrg <p><var>key</var> defaults to GCC version number, and can be overridden by the 1522 1.11 mrg <samp>--enable-win32-registry=<var>key</var></samp> option. Vendors and distributors 1523 1.1 mrg who use custom installers are encouraged to provide a different key, 1524 1.1 mrg perhaps one comprised of vendor name and GCC version number, to 1525 1.1 mrg avoid conflict with existing installations. This feature is enabled 1526 1.11 mrg by default, and can be disabled by <samp>--disable-win32-registry</samp> 1527 1.1 mrg option. This option has no effect on the other hosts. 1528 1.11 mrg </p> 1529 1.11 mrg </dd> 1530 1.14 mrg <dt><code>--nfp</code></dt> 1531 1.11 mrg <dd><p>Specify that the machine does not have a floating point unit. This 1532 1.11 mrg option only applies to ‘<samp>m68k-sun-sunos<var>n</var></samp>’. On any other 1533 1.11 mrg system, <samp>--nfp</samp> has no effect. 1534 1.11 mrg </p> 1535 1.11 mrg </dd> 1536 1.14 mrg <dt><code>--enable-werror</code></dt> 1537 1.14 mrg <dt><code>--disable-werror</code></dt> 1538 1.14 mrg <dt><code>--enable-werror=yes</code></dt> 1539 1.14 mrg <dt><code>--enable-werror=no</code></dt> 1540 1.11 mrg <dd><p>When you specify this option, it controls whether certain files in the 1541 1.11 mrg compiler are built with <samp>-Werror</samp> in bootstrap stage2 and later. 1542 1.11 mrg If you don’t specify it, <samp>-Werror</samp> is turned on for the main 1543 1.1 mrg development trunk. However it defaults to off for release branches and 1544 1.11 mrg final releases. The specific files which get <samp>-Werror</samp> are 1545 1.1 mrg controlled by the Makefiles. 1546 1.11 mrg </p> 1547 1.11 mrg </dd> 1548 1.14 mrg <dt><code>--enable-checking</code></dt> 1549 1.14 mrg <dt><code>--disable-checking</code></dt> 1550 1.14 mrg <dt><code>--enable-checking=<var>list</var></code></dt> 1551 1.11 mrg <dd><p>This option controls performing internal consistency checks in the compiler. 1552 1.11 mrg It does not change the generated code, but adds error checking of the 1553 1.11 mrg requested complexity. This slows down the compiler and may only work 1554 1.11 mrg properly if you are building the compiler with GCC. 1555 1.11 mrg </p> 1556 1.11 mrg <p>When the option is not specified, the active set of checks depends on context. 1557 1.11 mrg Namely, bootstrap stage 1 defaults to ‘<samp>--enable-checking=yes</samp>’, builds 1558 1.11 mrg from release branches or release archives default to 1559 1.11 mrg ‘<samp>--enable-checking=release</samp>’, and otherwise 1560 1.11 mrg ‘<samp>--enable-checking=yes,extra</samp>’ is used. When the option is 1561 1.11 mrg specified without a <var>list</var>, the result is the same as 1562 1.11 mrg ‘<samp>--enable-checking=yes</samp>’. Likewise, ‘<samp>--disable-checking</samp>’ is 1563 1.11 mrg equivalent to ‘<samp>--enable-checking=no</samp>’. 1564 1.11 mrg </p> 1565 1.11 mrg <p>The categories of checks available in <var>list</var> are ‘<samp>yes</samp>’ (most common 1566 1.11 mrg checks ‘<samp>assert,misc,gc,gimple,rtlflag,runtime,tree,types</samp>’), ‘<samp>no</samp>’ 1567 1.11 mrg (no checks at all), ‘<samp>all</samp>’ (all but ‘<samp>valgrind</samp>’), ‘<samp>release</samp>’ 1568 1.11 mrg (cheapest checks ‘<samp>assert,runtime</samp>’) or ‘<samp>none</samp>’ (same as ‘<samp>no</samp>’). 1569 1.11 mrg ‘<samp>release</samp>’ checks are always on and to disable them 1570 1.11 mrg ‘<samp>--disable-checking</samp>’ or ‘<samp>--enable-checking=no[,<other checks>]</samp>’ 1571 1.11 mrg must be explicitly requested. Disabling assertions makes the compiler and 1572 1.11 mrg runtime slightly faster but increases the risk of undetected internal errors 1573 1.11 mrg causing wrong code to be generated. 1574 1.11 mrg </p> 1575 1.11 mrg <p>Individual checks can be enabled with these flags: ‘<samp>assert</samp>’, ‘<samp>df</samp>’, 1576 1.11 mrg ‘<samp>extra</samp>’, ‘<samp>fold</samp>’, ‘<samp>gc</samp>’, ‘<samp>gcac</samp>’, ‘<samp>gimple</samp>’, 1577 1.11 mrg ‘<samp>misc</samp>’, ‘<samp>rtl</samp>’, ‘<samp>rtlflag</samp>’, ‘<samp>runtime</samp>’, ‘<samp>tree</samp>’, 1578 1.11 mrg ‘<samp>types</samp>’ and ‘<samp>valgrind</samp>’. ‘<samp>extra</samp>’ extends ‘<samp>misc</samp>’ 1579 1.11 mrg checking with extra checks that might affect code generation and should 1580 1.11 mrg therefore not differ between stage1 and later stages in bootstrap. 1581 1.11 mrg </p> 1582 1.11 mrg <p>The ‘<samp>valgrind</samp>’ check requires the external <code>valgrind</code> simulator, 1583 1.15 mrg available from <a href="https://valgrind.org">https://valgrind.org</a>. The ‘<samp>rtl</samp>’ checks are 1584 1.11 mrg expensive and the ‘<samp>df</samp>’, ‘<samp>gcac</samp>’ and ‘<samp>valgrind</samp>’ checks are very 1585 1.11 mrg expensive. 1586 1.11 mrg </p> 1587 1.11 mrg </dd> 1588 1.14 mrg <dt><code>--disable-stage1-checking</code></dt> 1589 1.14 mrg <dt><code>--enable-stage1-checking</code></dt> 1590 1.14 mrg <dt><code>--enable-stage1-checking=<var>list</var></code></dt> 1591 1.11 mrg <dd><p>This option affects only bootstrap build. If no <samp>--enable-checking</samp> 1592 1.11 mrg option is specified the stage1 compiler is built with ‘<samp>yes</samp>’ checking 1593 1.11 mrg enabled, otherwise the stage1 checking flags are the same as specified by 1594 1.11 mrg <samp>--enable-checking</samp>. To build the stage1 compiler with 1595 1.11 mrg different checking options use <samp>--enable-stage1-checking</samp>. 1596 1.11 mrg The list of checking options is the same as for <samp>--enable-checking</samp>. 1597 1.1 mrg If your system is too slow or too small to bootstrap a released compiler 1598 1.11 mrg with checking for stage1 enabled, you can use ‘<samp>--disable-stage1-checking</samp>’ 1599 1.1 mrg to disable checking for the stage1 compiler. 1600 1.11 mrg </p> 1601 1.11 mrg </dd> 1602 1.14 mrg <dt><code>--enable-coverage</code></dt> 1603 1.14 mrg <dt><code>--enable-coverage=<var>level</var></code></dt> 1604 1.11 mrg <dd><p>With this option, the compiler is built to collect self coverage 1605 1.1 mrg information, every time it is run. This is for internal development 1606 1.1 mrg purposes, and only works when the compiler is being built with gcc. The 1607 1.1 mrg <var>level</var> argument controls whether the compiler is built optimized or 1608 1.11 mrg not, values are ‘<samp>opt</samp>’ and ‘<samp>noopt</samp>’. For coverage analysis you 1609 1.1 mrg want to disable optimization, for performance analysis you want to 1610 1.1 mrg enable optimization. When coverage is enabled, the default level is 1611 1.1 mrg without optimization. 1612 1.11 mrg </p> 1613 1.11 mrg </dd> 1614 1.14 mrg <dt><code>--enable-gather-detailed-mem-stats</code></dt> 1615 1.11 mrg <dd><p>When this option is specified more detailed information on memory 1616 1.1 mrg allocation is gathered. This information is printed when using 1617 1.11 mrg <samp>-fmem-report</samp>. 1618 1.11 mrg </p> 1619 1.11 mrg </dd> 1620 1.14 mrg <dt><code>--enable-valgrind-annotations</code></dt> 1621 1.11 mrg <dd><p>Mark selected memory related operations in the compiler when run under 1622 1.7 mrg valgrind to suppress false positives. 1623 1.11 mrg </p> 1624 1.11 mrg </dd> 1625 1.14 mrg <dt><code>--enable-nls</code></dt> 1626 1.14 mrg <dt><code>--disable-nls</code></dt> 1627 1.11 mrg <dd><p>The <samp>--enable-nls</samp> option enables Native Language Support (NLS), 1628 1.1 mrg which lets GCC output diagnostics in languages other than American 1629 1.1 mrg English. Native Language Support is enabled by default if not doing a 1630 1.11 mrg canadian cross build. The <samp>--disable-nls</samp> option disables NLS. 1631 1.11 mrg </p> 1632 1.11 mrg </dd> 1633 1.14 mrg <dt><code>--with-included-gettext</code></dt> 1634 1.11 mrg <dd><p>If NLS is enabled, the <samp>--with-included-gettext</samp> option causes the build 1635 1.11 mrg procedure to prefer its copy of GNU <code>gettext</code>. 1636 1.11 mrg </p> 1637 1.11 mrg </dd> 1638 1.14 mrg <dt><code>--with-catgets</code></dt> 1639 1.11 mrg <dd><p>If NLS is enabled, and if the host lacks <code>gettext</code> but has the 1640 1.1 mrg inferior <code>catgets</code> interface, the GCC build procedure normally 1641 1.11 mrg ignores <code>catgets</code> and instead uses GCC’s copy of the GNU 1642 1.11 mrg <code>gettext</code> library. The <samp>--with-catgets</samp> option causes the 1643 1.11 mrg build procedure to use the host’s <code>catgets</code> in this situation. 1644 1.11 mrg </p> 1645 1.11 mrg </dd> 1646 1.14 mrg <dt><code>--with-libiconv-prefix=<var>dir</var></code></dt> 1647 1.11 mrg <dd><p>Search for libiconv header files in <samp><var>dir</var>/include</samp> and 1648 1.11 mrg libiconv library files in <samp><var>dir</var>/lib</samp>. 1649 1.11 mrg </p> 1650 1.11 mrg </dd> 1651 1.14 mrg <dt><code>--enable-obsolete</code></dt> 1652 1.11 mrg <dd><p>Enable configuration for an obsoleted system. If you attempt to 1653 1.1 mrg configure GCC for a system (build, host, or target) which has been 1654 1.1 mrg obsoleted, and you do not specify this flag, configure will halt with an 1655 1.1 mrg error message. 1656 1.11 mrg </p> 1657 1.11 mrg <p>All support for systems which have been obsoleted in one release of GCC 1658 1.1 mrg is removed entirely in the next major release, unless someone steps 1659 1.1 mrg forward to maintain the port. 1660 1.11 mrg </p> 1661 1.11 mrg </dd> 1662 1.14 mrg <dt><code>--enable-decimal-float</code></dt> 1663 1.14 mrg <dt><code>--enable-decimal-float=yes</code></dt> 1664 1.14 mrg <dt><code>--enable-decimal-float=no</code></dt> 1665 1.14 mrg <dt><code>--enable-decimal-float=bid</code></dt> 1666 1.14 mrg <dt><code>--enable-decimal-float=dpd</code></dt> 1667 1.14 mrg <dt><code>--disable-decimal-float</code></dt> 1668 1.11 mrg <dd><p>Enable (or disable) support for the C decimal floating point extension 1669 1.1 mrg that is in the IEEE 754-2008 standard. This is enabled by default only 1670 1.1 mrg on PowerPC, i386, and x86_64 GNU/Linux systems. Other systems may also 1671 1.1 mrg support it, but require the user to specifically enable it. You can 1672 1.1 mrg optionally control which decimal floating point format is used (either 1673 1.11 mrg ‘<samp>bid</samp>’ or ‘<samp>dpd</samp>’). The ‘<samp>bid</samp>’ (binary integer decimal) 1674 1.11 mrg format is default on i386 and x86_64 systems, and the ‘<samp>dpd</samp>’ 1675 1.1 mrg (densely packed decimal) format is default on PowerPC systems. 1676 1.11 mrg </p> 1677 1.11 mrg </dd> 1678 1.14 mrg <dt><code>--enable-fixed-point</code></dt> 1679 1.14 mrg <dt><code>--disable-fixed-point</code></dt> 1680 1.11 mrg <dd><p>Enable (or disable) support for C fixed-point arithmetic. 1681 1.1 mrg This option is enabled by default for some targets (such as MIPS) which 1682 1.1 mrg have hardware-support for fixed-point operations. On other targets, you 1683 1.1 mrg may enable this option manually. 1684 1.11 mrg </p> 1685 1.11 mrg </dd> 1686 1.14 mrg <dt><code>--with-long-double-128</code></dt> 1687 1.11 mrg <dd><p>Specify if <code>long double</code> type should be 128-bit by default on selected 1688 1.1 mrg GNU/Linux architectures. If using <code>--without-long-double-128</code>, 1689 1.11 mrg <code>long double</code> will be by default 64-bit, the same as <code>double</code> type. 1690 1.1 mrg When neither of these configure options are used, the default will be 1691 1.1 mrg 128-bit <code>long double</code> when built against GNU C Library 2.4 and later, 1692 1.1 mrg 64-bit <code>long double</code> otherwise. 1693 1.11 mrg </p> 1694 1.11 mrg </dd> 1695 1.14 mrg <dt><code>--with-long-double-format=ibm</code></dt> 1696 1.14 mrg <dt><code>--with-long-double-format=ieee</code></dt> 1697 1.11 mrg <dd><p>Specify whether <code>long double</code> uses the IBM extended double format 1698 1.11 mrg or the IEEE 128-bit floating point format on PowerPC Linux systems. 1699 1.11 mrg This configuration switch will only work on little endian PowerPC 1700 1.11 mrg Linux systems and on big endian 64-bit systems where the default cpu 1701 1.11 mrg is at least power7 (i.e. <samp>--with-cpu=power7</samp>, 1702 1.11 mrg <samp>--with-cpu=power8</samp>, or <samp>--with-cpu=power9</samp> is used). 1703 1.11 mrg </p> 1704 1.11 mrg <p>If you use the <samp>--with-long-double-64</samp> configuration option, 1705 1.11 mrg the <samp>--with-long-double-format=ibm</samp> and 1706 1.11 mrg <samp>--with-long-double-format=ieee</samp> options are ignored. 1707 1.11 mrg </p> 1708 1.11 mrg <p>The default <code>long double</code> format is to use IBM extended double. 1709 1.11 mrg Until all of the libraries are converted to use IEEE 128-bit floating 1710 1.11 mrg point, it is not recommended to use 1711 1.11 mrg <samp>--with-long-double-format=ieee</samp>. 1712 1.11 mrg </p> 1713 1.11 mrg </dd> 1714 1.14 mrg <dt><code>--enable-fdpic</code></dt> 1715 1.11 mrg <dd><p>On SH Linux systems, generate ELF FDPIC code. 1716 1.11 mrg </p> 1717 1.11 mrg </dd> 1718 1.14 mrg <dt><code>--with-gmp=<var>pathname</var></code></dt> 1719 1.14 mrg <dt><code>--with-gmp-include=<var>pathname</var></code></dt> 1720 1.14 mrg <dt><code>--with-gmp-lib=<var>pathname</var></code></dt> 1721 1.14 mrg <dt><code>--with-mpfr=<var>pathname</var></code></dt> 1722 1.14 mrg <dt><code>--with-mpfr-include=<var>pathname</var></code></dt> 1723 1.14 mrg <dt><code>--with-mpfr-lib=<var>pathname</var></code></dt> 1724 1.14 mrg <dt><code>--with-mpc=<var>pathname</var></code></dt> 1725 1.14 mrg <dt><code>--with-mpc-include=<var>pathname</var></code></dt> 1726 1.14 mrg <dt><code>--with-mpc-lib=<var>pathname</var></code></dt> 1727 1.11 mrg <dd><p>If you want to build GCC but do not have the GMP library, the MPFR 1728 1.1 mrg library and/or the MPC library installed in a standard location and 1729 1.3 mrg do not have their sources present in the GCC source tree then you 1730 1.3 mrg can explicitly specify the directory where they are installed 1731 1.11 mrg (‘<samp>--with-gmp=<var>gmpinstalldir</var></samp>’, 1732 1.11 mrg ‘<samp>--with-mpfr=<var>mpfrinstalldir</var></samp>’, 1733 1.11 mrg ‘<samp>--with-mpc=<var>mpcinstalldir</var></samp>’). The 1734 1.11 mrg <samp>--with-gmp=<var>gmpinstalldir</var></samp> option is shorthand for 1735 1.11 mrg <samp>--with-gmp-lib=<var>gmpinstalldir</var>/lib</samp> and 1736 1.11 mrg <samp>--with-gmp-include=<var>gmpinstalldir</var>/include</samp>. Likewise the 1737 1.11 mrg <samp>--with-mpfr=<var>mpfrinstalldir</var></samp> option is shorthand for 1738 1.11 mrg <samp>--with-mpfr-lib=<var>mpfrinstalldir</var>/lib</samp> and 1739 1.11 mrg <samp>--with-mpfr-include=<var>mpfrinstalldir</var>/include</samp>, also the 1740 1.11 mrg <samp>--with-mpc=<var>mpcinstalldir</var></samp> option is shorthand for 1741 1.11 mrg <samp>--with-mpc-lib=<var>mpcinstalldir</var>/lib</samp> and 1742 1.11 mrg <samp>--with-mpc-include=<var>mpcinstalldir</var>/include</samp>. If these 1743 1.1 mrg shorthand assumptions are not correct, you can use the explicit 1744 1.3 mrg include and lib options directly. You might also need to ensure the 1745 1.3 mrg shared libraries can be found by the dynamic linker when building and 1746 1.3 mrg using GCC, for example by setting the runtime shared library path 1747 1.11 mrg variable (<code>LD_LIBRARY_PATH</code> on GNU/Linux and Solaris systems). 1748 1.11 mrg </p> 1749 1.11 mrg <p>These flags are applicable to the host platform only. When building 1750 1.3 mrg a cross compiler, they will not be used to configure target libraries. 1751 1.11 mrg </p> 1752 1.11 mrg </dd> 1753 1.14 mrg <dt><code>--with-isl=<var>pathname</var></code></dt> 1754 1.14 mrg <dt><code>--with-isl-include=<var>pathname</var></code></dt> 1755 1.14 mrg <dt><code>--with-isl-lib=<var>pathname</var></code></dt> 1756 1.11 mrg <dd><p>If you do not have the isl library installed in a standard location and you 1757 1.5 mrg want to build GCC, you can explicitly specify the directory where it is 1758 1.11 mrg installed (‘<samp>--with-isl=<var>islinstalldir</var></samp>’). The 1759 1.11 mrg <samp>--with-isl=<var>islinstalldir</var></samp> option is shorthand for 1760 1.11 mrg <samp>--with-isl-lib=<var>islinstalldir</var>/lib</samp> and 1761 1.11 mrg <samp>--with-isl-include=<var>islinstalldir</var>/include</samp>. If this 1762 1.5 mrg shorthand assumption is not correct, you can use the explicit 1763 1.1 mrg include and lib options directly. 1764 1.11 mrg </p> 1765 1.11 mrg <p>These flags are applicable to the host platform only. When building 1766 1.3 mrg a cross compiler, they will not be used to configure target libraries. 1767 1.11 mrg </p> 1768 1.11 mrg </dd> 1769 1.14 mrg <dt><code>--with-stage1-ldflags=<var>flags</var></code></dt> 1770 1.11 mrg <dd><p>This option may be used to set linker flags to be used when linking 1771 1.1 mrg stage 1 of GCC. These are also used when linking GCC if configured with 1772 1.11 mrg <samp>--disable-bootstrap</samp>. If <samp>--with-stage1-libs</samp> is not set to a 1773 1.11 mrg value, then the default is ‘<samp>-static-libstdc++ -static-libgcc</samp>’, if 1774 1.7 mrg supported. 1775 1.11 mrg </p> 1776 1.11 mrg </dd> 1777 1.14 mrg <dt><code>--with-stage1-libs=<var>libs</var></code></dt> 1778 1.11 mrg <dd><p>This option may be used to set libraries to be used when linking stage 1 1779 1.1 mrg of GCC. These are also used when linking GCC if configured with 1780 1.11 mrg <samp>--disable-bootstrap</samp>. 1781 1.11 mrg </p> 1782 1.11 mrg </dd> 1783 1.14 mrg <dt><code>--with-boot-ldflags=<var>flags</var></code></dt> 1784 1.11 mrg <dd><p>This option may be used to set linker flags to be used when linking 1785 1.7 mrg stage 2 and later when bootstrapping GCC. If –with-boot-libs 1786 1.7 mrg is not is set to a value, then the default is 1787 1.11 mrg ‘<samp>-static-libstdc++ -static-libgcc</samp>’. 1788 1.11 mrg </p> 1789 1.11 mrg </dd> 1790 1.14 mrg <dt><code>--with-boot-libs=<var>libs</var></code></dt> 1791 1.11 mrg <dd><p>This option may be used to set libraries to be used when linking stage 2 1792 1.7 mrg and later when bootstrapping GCC. 1793 1.11 mrg </p> 1794 1.11 mrg </dd> 1795 1.14 mrg <dt><code>--with-debug-prefix-map=<var>map</var></code></dt> 1796 1.11 mrg <dd><p>Convert source directory names using <samp>-fdebug-prefix-map</samp> when 1797 1.1 mrg building runtime libraries. ‘<samp><var>map</var></samp>’ is a space-separated 1798 1.11 mrg list of maps of the form ‘<samp><var>old</var>=<var>new</var></samp>’. 1799 1.11 mrg </p> 1800 1.11 mrg </dd> 1801 1.14 mrg <dt><code>--enable-linker-build-id</code></dt> 1802 1.11 mrg <dd><p>Tells GCC to pass <samp>--build-id</samp> option to the linker for all final 1803 1.11 mrg links (links performed without the <samp>-r</samp> or <samp>--relocatable</samp> 1804 1.1 mrg option), if the linker supports it. If you specify 1805 1.11 mrg <samp>--enable-linker-build-id</samp>, but your linker does not 1806 1.11 mrg support <samp>--build-id</samp> option, a warning is issued and the 1807 1.11 mrg <samp>--enable-linker-build-id</samp> option is ignored. The default is off. 1808 1.11 mrg </p> 1809 1.11 mrg </dd> 1810 1.14 mrg <dt><code>--with-linker-hash-style=<var>choice</var></code></dt> 1811 1.11 mrg <dd><p>Tells GCC to pass <samp>--hash-style=<var>choice</var></samp> option to the 1812 1.3 mrg linker for all final links. <var>choice</var> can be one of 1813 1.11 mrg ‘<samp>sysv</samp>’, ‘<samp>gnu</samp>’, and ‘<samp>both</samp>’ where ‘<samp>sysv</samp>’ is the default. 1814 1.11 mrg </p> 1815 1.11 mrg </dd> 1816 1.14 mrg <dt><code>--enable-gnu-unique-object</code></dt> 1817 1.14 mrg <dt><code>--disable-gnu-unique-object</code></dt> 1818 1.11 mrg <dd><p>Tells GCC to use the gnu_unique_object relocation for C++ template 1819 1.1 mrg static data members and inline function local statics. Enabled by 1820 1.5 mrg default for a toolchain with an assembler that accepts it and 1821 1.1 mrg GLIBC 2.11 or above, otherwise disabled. 1822 1.11 mrg </p> 1823 1.11 mrg </dd> 1824 1.14 mrg <dt><code>--with-diagnostics-color=<var>choice</var></code></dt> 1825 1.11 mrg <dd><p>Tells GCC to use <var>choice</var> as the default for <samp>-fdiagnostics-color=</samp> 1826 1.5 mrg option (if not used explicitly on the command line). <var>choice</var> 1827 1.11 mrg can be one of ‘<samp>never</samp>’, ‘<samp>auto</samp>’, ‘<samp>always</samp>’, and ‘<samp>auto-if-env</samp>’ 1828 1.13 mrg where ‘<samp>auto</samp>’ is the default. ‘<samp>auto-if-env</samp>’ makes 1829 1.13 mrg <samp>-fdiagnostics-color=auto</samp> the default if <code>GCC_COLORS</code> 1830 1.13 mrg is present and non-empty in the environment of the compiler, and 1831 1.11 mrg <samp>-fdiagnostics-color=never</samp> otherwise. 1832 1.11 mrg </p> 1833 1.11 mrg </dd> 1834 1.14 mrg <dt><code>--with-diagnostics-urls=<var>choice</var></code></dt> 1835 1.13 mrg <dd><p>Tells GCC to use <var>choice</var> as the default for <samp>-fdiagnostics-urls=</samp> 1836 1.13 mrg option (if not used explicitly on the command line). <var>choice</var> 1837 1.13 mrg can be one of ‘<samp>never</samp>’, ‘<samp>auto</samp>’, ‘<samp>always</samp>’, and ‘<samp>auto-if-env</samp>’ 1838 1.13 mrg where ‘<samp>auto</samp>’ is the default. ‘<samp>auto-if-env</samp>’ makes 1839 1.13 mrg <samp>-fdiagnostics-urls=auto</samp> the default if <code>GCC_URLS</code> 1840 1.13 mrg or <code>TERM_URLS</code> is present and non-empty in the environment of the 1841 1.13 mrg compiler, and <samp>-fdiagnostics-urls=never</samp> otherwise. 1842 1.13 mrg </p> 1843 1.13 mrg </dd> 1844 1.14 mrg <dt><code>--enable-lto</code></dt> 1845 1.14 mrg <dt><code>--disable-lto</code></dt> 1846 1.11 mrg <dd><p>Enable support for link-time optimization (LTO). This is enabled by 1847 1.11 mrg default, and may be disabled using <samp>--disable-lto</samp>. 1848 1.11 mrg </p> 1849 1.11 mrg </dd> 1850 1.14 mrg <dt><code>--enable-linker-plugin-configure-flags=FLAGS</code></dt> 1851 1.14 mrg <dt><code>--enable-linker-plugin-flags=FLAGS</code></dt> 1852 1.11 mrg <dd><p>By default, linker plugins (such as the LTO plugin) are built for the 1853 1.5 mrg host system architecture. For the case that the linker has a 1854 1.5 mrg different (but run-time compatible) architecture, these flags can be 1855 1.5 mrg specified to build plugins that are compatible to the linker. For 1856 1.5 mrg example, if you are building GCC for a 64-bit x86_64 1857 1.12 mrg (‘<samp>x86_64-pc-linux-gnu</samp>’) host system, but have a 32-bit x86 1858 1.11 mrg GNU/Linux (‘<samp>i686-pc-linux-gnu</samp>’) linker executable (which is 1859 1.5 mrg executable on the former system), you can configure GCC as follows for 1860 1.5 mrg getting compatible linker plugins: 1861 1.11 mrg </p> 1862 1.14 mrg <div class="smallexample"> 1863 1.14 mrg <pre class="smallexample">% <var>srcdir</var>/configure \ 1864 1.12 mrg --host=x86_64-pc-linux-gnu \ 1865 1.11 mrg --enable-linker-plugin-configure-flags=--host=i686-pc-linux-gnu \ 1866 1.11 mrg --enable-linker-plugin-flags='CC=gcc\ -m32\ -Wl,-rpath,[...]/i686-pc-linux-gnu/lib' 1867 1.11 mrg </pre></div> 1868 1.11 mrg 1869 1.11 mrg </dd> 1870 1.14 mrg <dt><code>--with-plugin-ld=<var>pathname</var></code></dt> 1871 1.11 mrg <dd><p>Enable an alternate linker to be used at link-time optimization (LTO) 1872 1.11 mrg link time when <samp>-fuse-linker-plugin</samp> is enabled. 1873 1.3 mrg This linker should have plugin support such as gold starting with 1874 1.11 mrg version 2.20 or GNU ld starting with version 2.21. 1875 1.11 mrg See <samp>-fuse-linker-plugin</samp> for details. 1876 1.11 mrg </p> 1877 1.11 mrg </dd> 1878 1.14 mrg <dt><code>--enable-canonical-system-headers</code></dt> 1879 1.14 mrg <dt><code>--disable-canonical-system-headers</code></dt> 1880 1.11 mrg <dd><p>Enable system header path canonicalization for <samp>libcpp</samp>. This can 1881 1.3 mrg produce shorter header file paths in diagnostics and dependency output 1882 1.3 mrg files, but these changed header paths may conflict with some compilation 1883 1.3 mrg environments. Enabled by default, and may be disabled using 1884 1.11 mrg <samp>--disable-canonical-system-headers</samp>. 1885 1.11 mrg </p> 1886 1.11 mrg </dd> 1887 1.14 mrg <dt><code>--with-glibc-version=<var>major</var>.<var>minor</var></code></dt> 1888 1.11 mrg <dd><p>Tell GCC that when the GNU C Library (glibc) is used on the target it 1889 1.5 mrg will be version <var>major</var>.<var>minor</var> or later. Normally this can 1890 1.11 mrg be detected from the C library’s header files, but this option may be 1891 1.5 mrg needed when bootstrapping a cross toolchain without the header files 1892 1.5 mrg available for building the initial bootstrap compiler. 1893 1.11 mrg </p> 1894 1.11 mrg <p>If GCC is configured with some multilibs that use glibc and some that 1895 1.11 mrg do not, this option applies only to the multilibs that use glibc. 1896 1.5 mrg However, such configurations may not work well as not all the relevant 1897 1.5 mrg configuration in GCC is on a per-multilib basis. 1898 1.11 mrg </p> 1899 1.11 mrg </dd> 1900 1.14 mrg <dt><code>--enable-as-accelerator-for=<var>target</var></code></dt> 1901 1.11 mrg <dd><p>Build as offload target compiler. Specify offload host triple by <var>target</var>. 1902 1.11 mrg </p> 1903 1.11 mrg </dd> 1904 1.14 mrg <dt><code>--enable-offload-targets=<var>target1</var>[=<var>path1</var>],…,<var>targetN</var>[=<var>pathN</var>]</code></dt> 1905 1.11 mrg <dd><p>Enable offloading to targets <var>target1</var>, …, <var>targetN</var>. 1906 1.5 mrg Offload compilers are expected to be already installed. Default search 1907 1.5 mrg path for them is <samp><var>exec-prefix</var></samp>, but it can be changed by 1908 1.11 mrg specifying paths <var>path1</var>, …, <var>pathN</var>. 1909 1.11 mrg </p> 1910 1.14 mrg <div class="smallexample"> 1911 1.14 mrg <pre class="smallexample">% <var>srcdir</var>/configure \ 1912 1.15 mrg --enable-offload-targets=x86_64-intelmicemul-linux-gnu=/path/to/x86_64/compiler,nvptx-none 1913 1.11 mrg </pre></div> 1914 1.7 mrg 1915 1.15 mrg </dd> 1916 1.15 mrg <dt><code>--enable-offload-defaulted</code></dt> 1917 1.15 mrg <dd> 1918 1.15 mrg <p>Tell GCC that configured but not installed offload compilers and libgomp 1919 1.15 mrg plugins are silently ignored. Useful for distribution compilers where 1920 1.15 mrg those are in separate optional packages and where the presence or absence 1921 1.15 mrg of those optional packages should determine the actual supported offloading 1922 1.15 mrg target set rather than the GCC configure-time selection. 1923 1.11 mrg </p> 1924 1.11 mrg </dd> 1925 1.14 mrg <dt><code>--with-hsa-runtime=<var>pathname</var></code></dt> 1926 1.14 mrg <dt><code>--with-hsa-runtime-include=<var>pathname</var></code></dt> 1927 1.14 mrg <dt><code>--with-hsa-runtime-lib=<var>pathname</var></code></dt> 1928 1.11 mrg <dd> 1929 1.15 mrg <p>If you configure GCC with offloading which uses an HSA run-time such as 1930 1.15 mrg AMDGCN but do not have the HSA run-time library installed in a standard 1931 1.15 mrg location then you can explicitly specify the directory where they are 1932 1.15 mrg installed. The <samp>--with-hsa-runtime=<var>hsainstalldir</var></samp> option 1933 1.15 mrg is a shorthand for 1934 1.11 mrg <samp>--with-hsa-runtime-lib=<var>hsainstalldir</var>/lib</samp> and 1935 1.11 mrg <samp>--with-hsa-runtime-include=<var>hsainstalldir</var>/include</samp>. 1936 1.11 mrg </p> 1937 1.11 mrg </dd> 1938 1.14 mrg <dt><code>--enable-cet</code></dt> 1939 1.14 mrg <dt><code>--disable-cet</code></dt> 1940 1.11 mrg <dd><p>Enable building target run-time libraries with control-flow 1941 1.11 mrg instrumentation, see <samp>-fcf-protection</samp> option. When 1942 1.11 mrg <code>--enable-cet</code> is specified target libraries are configured 1943 1.11 mrg to add <samp>-fcf-protection</samp> and, if needed, other target 1944 1.11 mrg specific options to a set of building options. 1945 1.11 mrg </p> 1946 1.15 mrg <p><code>--enable-cet=auto</code> is default. CET is enabled on Linux/x86 if 1947 1.15 mrg target binutils supports <code>Intel CET</code> instructions and disabled 1948 1.15 mrg otherwise. In this case, the target libraries are configured to get 1949 1.15 mrg additional <samp>-fcf-protection</samp> option. 1950 1.12 mrg </p> 1951 1.12 mrg </dd> 1952 1.14 mrg <dt><code>--with-riscv-attribute=‘<samp>yes</samp>’, ‘<samp>no</samp>’ or ‘<samp>default</samp>’</code></dt> 1953 1.12 mrg <dd><p>Generate RISC-V attribute by default, in order to record extra build 1954 1.12 mrg information in object. 1955 1.12 mrg </p> 1956 1.12 mrg <p>The option is disabled by default. It is enabled on RISC-V/ELF (bare-metal) 1957 1.12 mrg target if target binutils supported. 1958 1.15 mrg </p> 1959 1.15 mrg </dd> 1960 1.15 mrg <dt><code>--enable-s390-excess-float-precision</code></dt> 1961 1.15 mrg <dt><code>--disable-s390-excess-float-precision</code></dt> 1962 1.15 mrg <dd><p>On s390(x) targets, enable treatment of float expressions with double precision 1963 1.15 mrg when in standards-compliant mode (e.g., when <code>--std=c99</code> or 1964 1.15 mrg <code>-fexcess-precision=standard</code> are given). 1965 1.15 mrg </p> 1966 1.15 mrg <p>For a native build and cross compiles that have target headers, the option’s 1967 1.15 mrg default is derived from glibc’s behavior. When glibc clamps float_t to double, 1968 1.15 mrg GCC follows and enables the option. For other cross compiles, the default is 1969 1.15 mrg disabled. 1970 1.15 mrg </p> 1971 1.15 mrg </dd> 1972 1.15 mrg <dt><code>--with-zstd=<var>pathname</var></code></dt> 1973 1.15 mrg <dt><code>--with-zstd-include=<var>pathname</var></code></dt> 1974 1.15 mrg <dt><code>--with-zstd-lib=<var>pathname</var></code></dt> 1975 1.15 mrg <dd><p>If you do not have the <code>zstd</code> library installed in a standard 1976 1.15 mrg location and you want to build GCC, you can explicitly specify the 1977 1.15 mrg directory where it is installed (‘<samp>--with-zstd=<var>zstdinstalldir</var></samp>’). 1978 1.15 mrg The <samp>--with-zstd=<var>zstdinstalldir</var></samp> option is shorthand for 1979 1.15 mrg <samp>--with-zstd-lib=<var>zstdinstalldir</var>/lib</samp> and 1980 1.15 mrg <samp>--with-zstd-include=<var>zstdinstalldir</var>/include</samp>. If this 1981 1.15 mrg shorthand assumption is not correct, you can use the explicit 1982 1.15 mrg include and lib options directly. 1983 1.15 mrg </p> 1984 1.15 mrg <p>These flags are applicable to the host platform only. When building 1985 1.15 mrg a cross compiler, they will not be used to configure target libraries. 1986 1.11 mrg </p></dd> 1987 1.6 mrg </dl> 1988 1.1 mrg 1989 1.14 mrg <a name="Cross-Compiler-Specific-Options"></a> 1990 1.14 mrg <h4 class="subheading">Cross-Compiler-Specific Options</h4> 1991 1.1 mrg <p>The following options only apply to building cross compilers. 1992 1.11 mrg </p> 1993 1.11 mrg <dl compact="compact"> 1994 1.14 mrg <dt><code>--with-toolexeclibdir=<var>dir</var></code></dt> 1995 1.13 mrg <dd><p>Specify the installation directory for libraries built with a cross compiler. 1996 1.13 mrg The default is <samp>${gcc_tooldir}/lib</samp>. 1997 1.13 mrg </p> 1998 1.13 mrg </dd> 1999 1.14 mrg <dt><code>--with-sysroot</code></dt> 2000 1.14 mrg <dt><code>--with-sysroot=<var>dir</var></code></dt> 2001 1.11 mrg <dd><p>Tells GCC to consider <var>dir</var> as the root of a tree that contains 2002 1.11 mrg (a subset of) the root filesystem of the target operating system. 2003 1.1 mrg Target system headers, libraries and run-time object files will be 2004 1.3 mrg searched for in there. More specifically, this acts as if 2005 1.11 mrg <samp>--sysroot=<var>dir</var></samp> was added to the default options of the built 2006 1.1 mrg compiler. The specified directory is not copied into the 2007 1.11 mrg install tree, unlike the options <samp>--with-headers</samp> and 2008 1.11 mrg <samp>--with-libs</samp> that this option obsoletes. The default value, 2009 1.11 mrg in case <samp>--with-sysroot</samp> is not given an argument, is 2010 1.11 mrg <samp>${gcc_tooldir}/sys-root</samp>. If the specified directory is a 2011 1.11 mrg subdirectory of <samp>${exec_prefix}</samp>, then it will be found relative to 2012 1.1 mrg the GCC binaries if the installation tree is moved. 2013 1.11 mrg </p> 2014 1.11 mrg <p>This option affects the system root for the compiler used to build 2015 1.1 mrg target libraries (which runs on the build system) and the compiler newly 2016 1.1 mrg installed with <code>make install</code>; it does not affect the compiler which is 2017 1.1 mrg used to build GCC itself. 2018 1.11 mrg </p> 2019 1.11 mrg <p>If you specify the <samp>--with-native-system-header-dir=<var>dirname</var></samp> 2020 1.3 mrg option then the compiler will search that directory within <var>dirname</var> for 2021 1.11 mrg native system headers rather than the default <samp>/usr/include</samp>. 2022 1.11 mrg </p> 2023 1.11 mrg </dd> 2024 1.14 mrg <dt><code>--with-build-sysroot</code></dt> 2025 1.14 mrg <dt><code>--with-build-sysroot=<var>dir</var></code></dt> 2026 1.11 mrg <dd><p>Tells GCC to consider <var>dir</var> as the system root (see 2027 1.11 mrg <samp>--with-sysroot</samp>) while building target libraries, instead of 2028 1.11 mrg the directory specified with <samp>--with-sysroot</samp>. This option is 2029 1.11 mrg only useful when you are already using <samp>--with-sysroot</samp>. You 2030 1.11 mrg can use <samp>--with-build-sysroot</samp> when you are configuring with 2031 1.11 mrg <samp>--prefix</samp> set to a directory that is different from the one in 2032 1.1 mrg which you are installing GCC and your target libraries. 2033 1.11 mrg </p> 2034 1.11 mrg <p>This option affects the system root for the compiler used to build 2035 1.1 mrg target libraries (which runs on the build system); it does not affect 2036 1.1 mrg the compiler which is used to build GCC itself. 2037 1.11 mrg </p> 2038 1.11 mrg <p>If you specify the <samp>--with-native-system-header-dir=<var>dirname</var></samp> 2039 1.3 mrg option then the compiler will search that directory within <var>dirname</var> for 2040 1.11 mrg native system headers rather than the default <samp>/usr/include</samp>. 2041 1.11 mrg </p> 2042 1.11 mrg </dd> 2043 1.14 mrg <dt><code>--with-headers</code></dt> 2044 1.14 mrg <dt><code>--with-headers=<var>dir</var></code></dt> 2045 1.11 mrg <dd><p>Deprecated in favor of <samp>--with-sysroot</samp>. 2046 1.11 mrg Specifies that target headers are available when building a cross compiler. 2047 1.1 mrg The <var>dir</var> argument specifies a directory which has the target include 2048 1.11 mrg files. These include files will be copied into the <samp>gcc</samp> install 2049 1.11 mrg directory. <em>This option with the <var>dir</var> argument is required</em> when 2050 1.11 mrg building a cross compiler, if <samp><var>prefix</var>/<var>target</var>/sys-include</samp> 2051 1.11 mrg doesn’t pre-exist. If <samp><var>prefix</var>/<var>target</var>/sys-include</samp> does 2052 1.11 mrg pre-exist, the <var>dir</var> argument may be omitted. <code>fixincludes</code> 2053 1.1 mrg will be run on these files to make them compatible with GCC. 2054 1.11 mrg </p> 2055 1.11 mrg </dd> 2056 1.14 mrg <dt><code>--without-headers</code></dt> 2057 1.11 mrg <dd><p>Tells GCC not use any target headers from a libc when building a cross 2058 1.1 mrg compiler. When crossing to GNU/Linux, you need the headers so GCC 2059 1.1 mrg can build the exception handling for libgcc. 2060 1.11 mrg </p> 2061 1.11 mrg </dd> 2062 1.14 mrg <dt><code>--with-libs</code></dt> 2063 1.14 mrg <dt><code>--with-libs="<var>dir1</var> <var>dir2</var> … <var>dirN</var>"</code></dt> 2064 1.11 mrg <dd><p>Deprecated in favor of <samp>--with-sysroot</samp>. 2065 1.1 mrg Specifies a list of directories which contain the target runtime 2066 1.11 mrg libraries. These libraries will be copied into the <samp>gcc</samp> install 2067 1.1 mrg directory. If the directory list is omitted, this option has no 2068 1.1 mrg effect. 2069 1.11 mrg </p> 2070 1.11 mrg </dd> 2071 1.14 mrg <dt><code>--with-newlib</code></dt> 2072 1.11 mrg <dd><p>Specifies that ‘<samp>newlib</samp>’ is 2073 1.1 mrg being used as the target C library. This causes <code>__eprintf</code> to be 2074 1.11 mrg omitted from <samp>libgcc.a</samp> on the assumption that it will be provided by 2075 1.11 mrg ‘<samp>newlib</samp>’. 2076 1.11 mrg </p> 2077 1.13 mrg <a name="avr"></a> 2078 1.11 mrg </dd> 2079 1.14 mrg <dt><code>--with-avrlibc</code></dt> 2080 1.13 mrg <dd><p>Only supported for the AVR target. Specifies that ‘<samp>AVR-Libc</samp>’ is 2081 1.13 mrg being used as the target C library. This causes float support 2082 1.11 mrg functions like <code>__addsf3</code> to be omitted from <samp>libgcc.a</samp> on 2083 1.11 mrg the assumption that it will be provided by <samp>libm.a</samp>. For more 2084 1.15 mrg technical details, cf. <a href="https://gcc.gnu.org/PR54461">PR54461</a>. 2085 1.13 mrg It is not supported for 2086 1.3 mrg RTEMS configurations, which currently use newlib. The option is 2087 1.3 mrg supported since version 4.7.2 and is the default in 4.8.0 and newer. 2088 1.11 mrg </p> 2089 1.11 mrg </dd> 2090 1.14 mrg <dt><code>--with-double={32|64|32,64|64,32}</code></dt> 2091 1.14 mrg <dt><code>--with-long-double={32|64|32,64|64,32|double}</code></dt> 2092 1.13 mrg <dd><p>Only supported for the AVR target since version 10. 2093 1.13 mrg Specify the default layout available for the C/C++ ‘<samp>double</samp>’ 2094 1.13 mrg and ‘<samp>long double</samp>’ type, respectively. The following rules apply: 2095 1.13 mrg </p><ul> 2096 1.13 mrg <li> The first value after the ‘<samp>=</samp>’ specifies the default layout (in bits) 2097 1.13 mrg of the type and also the default for the <samp>-mdouble=</samp> resp. 2098 1.13 mrg <samp>-mlong-double=</samp> compiler option. 2099 1.13 mrg </li><li> If more than one value is specified, respective multilib variants are 2100 1.13 mrg available, and <samp>-mdouble=</samp> resp. <samp>-mlong-double=</samp> acts 2101 1.13 mrg as a multilib option. 2102 1.13 mrg </li><li> If <samp>--with-long-double=double</samp> is specified, ‘<samp>double</samp>’ and 2103 1.13 mrg ‘<samp>long double</samp>’ will have the same layout. 2104 1.13 mrg </li><li> The defaults are <samp>--with-long-double=64,32</samp> and 2105 1.13 mrg <samp>--with-double=32,64</samp>. The default ‘<samp>double</samp>’ layout imposed by 2106 1.13 mrg the latter is compatible with older versions of the compiler that implement 2107 1.13 mrg ‘<samp>double</samp>’ as a 32-bit type, which does not comply to the language standard. 2108 1.13 mrg </li></ul> 2109 1.13 mrg <p>Not all combinations of <samp>--with-double=</samp> and 2110 1.13 mrg <samp>--with-long-double=</samp> are valid. For example, the combination 2111 1.13 mrg <samp>--with-double=32,64</samp> <samp>--with-long-double=32</samp> will be 2112 1.13 mrg rejected because the first option specifies the availability of 2113 1.13 mrg multilibs for ‘<samp>double</samp>’, whereas the second option implies 2114 1.13 mrg that ‘<samp>long double</samp>’ — and hence also ‘<samp>double</samp>’ — is always 2115 1.13 mrg 32 bits wide. 2116 1.13 mrg </p> 2117 1.13 mrg </dd> 2118 1.14 mrg <dt><code>--with-double-comparison={tristate|bool|libf7}</code></dt> 2119 1.13 mrg <dd><p>Only supported for the AVR target since version 10. 2120 1.13 mrg Specify what result format is returned by library functions that 2121 1.13 mrg compare 64-bit floating point values (<code>DFmode</code>). 2122 1.13 mrg The GCC default is ‘<samp>tristate</samp>’. If the floating point 2123 1.13 mrg implementation returns a boolean instead, set it to ‘<samp>bool</samp>’. 2124 1.13 mrg </p> 2125 1.13 mrg </dd> 2126 1.14 mrg <dt><code>--with-libf7={libgcc|math|math-symbols|no}</code></dt> 2127 1.13 mrg <dd><p>Only supported for the AVR target since version 10. 2128 1.13 mrg Specify to which degree code from LibF7 is included in libgcc. 2129 1.13 mrg LibF7 is an ad-hoc, AVR-specific, 64-bit floating point emulation 2130 1.13 mrg written in C and (inline) assembly. ‘<samp>libgcc</samp>’ adds support 2131 1.13 mrg for functions that one would usually expect in libgcc like double addition, 2132 1.13 mrg double comparisons and double conversions. ‘<samp>math</samp>’ also adds routines 2133 1.13 mrg that one would expect in <samp>libm.a</samp>, but with <code>__</code> (two underscores) 2134 1.13 mrg prepended to the symbol names as specified by <samp>math.h</samp>. 2135 1.13 mrg ‘<samp>math-symbols</samp>’ also defines weak aliases for the functions 2136 1.13 mrg declared in <samp>math.h</samp>. However, <code>--with-libf7</code> won’t 2137 1.13 mrg install no <samp>math.h</samp> header file whatsoever, this file must come 2138 1.13 mrg from elsewhere. This option sets <samp>--with-double-comparison</samp> 2139 1.13 mrg to ‘<samp>bool</samp>’. 2140 1.13 mrg </p> 2141 1.13 mrg </dd> 2142 1.14 mrg <dt><code>--with-nds32-lib=<var>library</var></code></dt> 2143 1.11 mrg <dd><p>Specifies that <var>library</var> setting is used for building <samp>libgcc.a</samp>. 2144 1.11 mrg Currently, the valid <var>library</var> is ‘<samp>newlib</samp>’ or ‘<samp>mculib</samp>’. 2145 1.5 mrg This option is only supported for the NDS32 target. 2146 1.11 mrg </p> 2147 1.11 mrg </dd> 2148 1.14 mrg <dt><code>--with-build-time-tools=<var>dir</var></code></dt> 2149 1.11 mrg <dd><p>Specifies where to find the set of target tools (assembler, linker, etc.) 2150 1.1 mrg that will be used while building GCC itself. This option can be useful 2151 1.1 mrg if the directory layouts are different between the system you are building 2152 1.1 mrg GCC on, and the system where you will deploy it. 2153 1.11 mrg </p> 2154 1.11 mrg <p>For example, on an ‘<samp>ia64-hp-hpux</samp>’ system, you may have the GNU 2155 1.11 mrg assembler and linker in <samp>/usr/bin</samp>, and the native tools in a 2156 1.6 mrg different path, and build a toolchain that expects to find the 2157 1.11 mrg native tools in <samp>/usr/bin</samp>. 2158 1.11 mrg </p> 2159 1.11 mrg <p>When you use this option, you should ensure that <var>dir</var> includes 2160 1.11 mrg <code>ar</code>, <code>as</code>, <code>ld</code>, <code>nm</code>, 2161 1.11 mrg <code>ranlib</code> and <code>strip</code> if necessary, and possibly 2162 1.11 mrg <code>objdump</code>. Otherwise, GCC may use an inconsistent set of 2163 1.11 mrg tools. 2164 1.11 mrg </p></dd> 2165 1.6 mrg </dl> 2166 1.1 mrg 2167 1.14 mrg <a name="Overriding-configure-test-results"></a> 2168 1.14 mrg <h4 class="subsubheading">Overriding <code>configure</code> test results</h4> 2169 1.1 mrg 2170 1.6 mrg <p>Sometimes, it might be necessary to override the result of some 2171 1.11 mrg <code>configure</code> test, for example in order to ease porting to a new 2172 1.11 mrg system or work around a bug in a test. The toplevel <code>configure</code> 2173 1.6 mrg script provides three variables for this: 2174 1.11 mrg </p> 2175 1.11 mrg <dl compact="compact"> 2176 1.14 mrg <dt><code>build_configargs</code></dt> 2177 1.14 mrg <dd><a name="index-build_005fconfigargs"></a> 2178 1.14 mrg <p>The contents of this variable is passed to all build <code>configure</code> 2179 1.6 mrg scripts. 2180 1.11 mrg </p> 2181 1.11 mrg </dd> 2182 1.14 mrg <dt><code>host_configargs</code></dt> 2183 1.14 mrg <dd><a name="index-host_005fconfigargs"></a> 2184 1.14 mrg <p>The contents of this variable is passed to all host <code>configure</code> 2185 1.6 mrg scripts. 2186 1.11 mrg </p> 2187 1.11 mrg </dd> 2188 1.14 mrg <dt><code>target_configargs</code></dt> 2189 1.14 mrg <dd><a name="index-target_005fconfigargs"></a> 2190 1.14 mrg <p>The contents of this variable is passed to all target <code>configure</code> 2191 1.6 mrg scripts. 2192 1.11 mrg </p> 2193 1.11 mrg </dd> 2194 1.11 mrg </dl> 2195 1.1 mrg 2196 1.11 mrg <p>In order to avoid shell and <code>make</code> quoting issues for complex 2197 1.11 mrg overrides, you can pass a setting for <code>CONFIG_SITE</code> and set 2198 1.6 mrg variables in the site file. 2199 1.11 mrg </p> 2200 1.14 mrg <a name="Objective-C-Specific-Options"></a> 2201 1.14 mrg <h4 class="subheading">Objective-C-Specific Options</h4> 2202 1.7 mrg 2203 1.10 mrg <p>The following options apply to the build of the Objective-C runtime library. 2204 1.11 mrg </p> 2205 1.11 mrg <dl compact="compact"> 2206 1.14 mrg <dt><code>--enable-objc-gc</code></dt> 2207 1.11 mrg <dd><p>Specify that an additional variant of the GNU Objective-C runtime library 2208 1.10 mrg is built, using an external build of the Boehm-Demers-Weiser garbage 2209 1.13 mrg collector (<a href="https://www.hboehm.info/gc/">https://www.hboehm.info/gc/</a>). This library needs to be 2210 1.10 mrg available for each multilib variant, unless configured with 2211 1.11 mrg <samp>--enable-objc-gc=‘<samp>auto</samp>’</samp> in which case the build of the 2212 1.10 mrg additional runtime library is skipped when not available and the build 2213 1.10 mrg continues. 2214 1.11 mrg </p> 2215 1.11 mrg </dd> 2216 1.14 mrg <dt><code>--with-target-bdw-gc=<var>list</var></code></dt> 2217 1.14 mrg <dt><code>--with-target-bdw-gc-include=<var>list</var></code></dt> 2218 1.14 mrg <dt><code>--with-target-bdw-gc-lib=<var>list</var></code></dt> 2219 1.11 mrg <dd><p>Specify search directories for the garbage collector header files and 2220 1.10 mrg libraries. <var>list</var> is a comma separated list of key value pairs of the 2221 1.11 mrg form ‘<samp><var>multilibdir</var>=<var>path</var></samp>’, where the default multilib key 2222 1.11 mrg is named as ‘<samp>.</samp>’ (dot), or is omitted (e.g. 2223 1.11 mrg ‘<samp>--with-target-bdw-gc=/opt/bdw-gc,32=/opt-bdw-gc32</samp>’). 2224 1.11 mrg </p> 2225 1.11 mrg <p>The options <samp>--with-target-bdw-gc-include</samp> and 2226 1.11 mrg <samp>--with-target-bdw-gc-lib</samp> must always be specified together 2227 1.10 mrg for each multilib variant and they take precedence over 2228 1.11 mrg <samp>--with-target-bdw-gc</samp>. If <samp>--with-target-bdw-gc-include</samp> 2229 1.10 mrg is missing values for a multilib, then the value for the default 2230 1.11 mrg multilib is used (e.g. ‘<samp>--with-target-bdw-gc-include=/opt/bdw-gc/include</samp>’ 2231 1.11 mrg ‘<samp>--with-target-bdw-gc-lib=/opt/bdw-gc/lib64,32=/opt-bdw-gc/lib32</samp>’). 2232 1.10 mrg If none of these options are specified, the library is assumed in 2233 1.11 mrg default locations. 2234 1.11 mrg </p></dd> 2235 1.6 mrg </dl> 2236 1.1 mrg 2237 1.14 mrg <a name="D-Specific-Options"></a> 2238 1.14 mrg <h4 class="subheading">D-Specific Options</h4> 2239 1.12 mrg 2240 1.12 mrg <p>The following options apply to the build of the D runtime library. 2241 1.12 mrg </p> 2242 1.12 mrg <dl compact="compact"> 2243 1.14 mrg <dt><code>--enable-libphobos-checking</code></dt> 2244 1.14 mrg <dt><code>--disable-libphobos-checking</code></dt> 2245 1.14 mrg <dt><code>--enable-libphobos-checking=<var>list</var></code></dt> 2246 1.13 mrg <dd><p>This option controls whether run-time checks and contracts are compiled into 2247 1.13 mrg the D runtime library. When the option is not specified, the library is built 2248 1.13 mrg with ‘<samp>release</samp>’ checking. When the option is specified without a 2249 1.13 mrg <var>list</var>, the result is the same as ‘<samp>--enable-libphobos-checking=yes</samp>’. 2250 1.13 mrg Likewise, ‘<samp>--disable-libphobos-checking</samp>’ is equivalent to 2251 1.13 mrg ‘<samp>--enable-libphobos-checking=no</samp>’. 2252 1.13 mrg </p> 2253 1.13 mrg <p>The categories of checks available in <var>list</var> are ‘<samp>yes</samp>’ (compiles 2254 1.13 mrg libphobos with <samp>-fno-release</samp>), ‘<samp>no</samp>’ (compiles libphobos with 2255 1.13 mrg <samp>-frelease</samp>), ‘<samp>all</samp>’ (same as ‘<samp>yes</samp>’), ‘<samp>none</samp>’ or 2256 1.13 mrg ‘<samp>release</samp>’ (same as ‘<samp>no</samp>’). 2257 1.13 mrg </p> 2258 1.13 mrg <p>Individual checks available in <var>list</var> are ‘<samp>assert</samp>’ (compiles libphobos 2259 1.13 mrg with an extra option <samp>-fassert</samp>). 2260 1.13 mrg </p> 2261 1.13 mrg </dd> 2262 1.14 mrg <dt><code>--with-libphobos-druntime-only</code></dt> 2263 1.14 mrg <dt><code>--with-libphobos-druntime-only=<var>choice</var></code></dt> 2264 1.13 mrg <dd><p>Specify whether to build only the core D runtime library (druntime), or both 2265 1.13 mrg the core and standard library (phobos) into libphobos. This is useful for 2266 1.13 mrg targets that have full support in druntime, but no or incomplete support 2267 1.13 mrg in phobos. <var>choice</var> can be one of ‘<samp>auto</samp>’, ‘<samp>yes</samp>’, and ‘<samp>no</samp>’ 2268 1.13 mrg where ‘<samp>auto</samp>’ is the default. 2269 1.13 mrg </p> 2270 1.13 mrg <p>When the option is not specified, the default choice ‘<samp>auto</samp>’ means that it 2271 1.13 mrg is inferred whether the target has support for the phobos standard library. 2272 1.13 mrg When the option is specified without a <var>choice</var>, the result is the same as 2273 1.13 mrg ‘<samp>--with-libphobos-druntime-only=yes</samp>’. 2274 1.13 mrg </p> 2275 1.13 mrg </dd> 2276 1.14 mrg <dt><code>--with-target-system-zlib</code></dt> 2277 1.12 mrg <dd><p>Use installed ‘<samp>zlib</samp>’ rather than that included with GCC. This needs 2278 1.12 mrg to be available for each multilib variant, unless configured with 2279 1.12 mrg <samp>--with-target-system-zlib=‘<samp>auto</samp>’</samp> in which case the GCC included 2280 1.12 mrg ‘<samp>zlib</samp>’ is only used when the system installed library is not available. 2281 1.12 mrg </p></dd> 2282 1.12 mrg </dl> 2283 1.12 mrg 2284 1.11 mrg <hr /> 2285 1.11 mrg <p> 2286 1.8 mrg <p><a href="./index.html">Return to the GCC Installation page</a> 2287 1.11 mrg </p> 2288 1.11 mrg 2289 1.11 mrg 2290 1.11 mrg 2291 1.11 mrg 2292 1.11 mrg 2293 1.11 mrg 2294 1.11 mrg 2295 1.11 mrg 2296 1.11 mrg 2297 1.1 mrg 2298 1.11 mrg </body> 2299 1.11 mrg </html> 2300
Indexes created Sat Jul 18 00:24:37 UTC 2026