1 <!DOCTYPE html> 2 <html> 3 <!-- Created by GNU Texinfo 7.2, https://www.gnu.org/software/texinfo/ --> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 6 <!-- Copyright 1988-2024 Free Software Foundation, Inc. 7 8 Permission is granted to copy, distribute and/or modify this document 9 under the terms of the GNU Free Documentation License, Version 1.3 or 10 any later version published by the Free Software Foundation; with no 11 Invariant Sections, the Front-Cover texts being (a) (see below), and 12 with the Back-Cover Texts being (b) (see below). A copy of the 13 license is included in the section entitled "GNU 14 Free Documentation License". 15 16 (a) The FSF's Front-Cover Text is: 17 18 A GNU Manual 19 20 (b) The FSF's Back-Cover Text is: 21 22 You have freedom to copy and modify this GNU Manual, like GNU 23 software. Copies published by the Free Software Foundation raise 24 funds for GNU development. --> 25 <title>Installing GCC: Configuration</title> 26 27 <meta name="description" content="Installing GCC: Configuration"> 28 <meta name="keywords" content="Installing GCC: Configuration"> 29 <meta name="resource-type" content="document"> 30 <meta name="distribution" content="global"> 31 <meta name="Generator" content="makeinfo"> 32 <meta name="viewport" content="width=device-width,initial-scale=1"> 33 34 <style type="text/css"> 35 <!-- 36 a.copiable-link {visibility: hidden; text-decoration: none; line-height: 0em} 37 div.example {margin-left: 3.2em} 38 span:hover a.copiable-link {visibility: visible} 39 ul.mark-bullet {list-style-type: disc} 40 ul.mark-minus {list-style-type: "\2212"} 41 --> 42 </style> 43 44 45 </head> 46 47 <body lang="en"> 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 <a class="index-entry-id" id="index-Configuration"></a> 71 <a class="index-entry-id" id="index-Installing-GCC_003a-Configuration"></a> 72 73 <p>Like most GNU software, GCC must be configured before it can be built. 74 This document describes the recommended configuration procedure 75 for both native and cross targets. 76 </p> 77 <p>We use <var class="var">srcdir</var> to refer to the toplevel source directory for 78 GCC; we use <var class="var">objdir</var> to refer to the toplevel build/object directory. 79 </p> 80 <p>If you obtained the sources by cloning the repository, <var class="var">srcdir</var> 81 must refer to the top <samp class="file">gcc</samp> directory, the one where the 82 <samp class="file">MAINTAINERS</samp> file can be found, and not its <samp class="file">gcc</samp> 83 subdirectory, otherwise the build will fail. 84 </p> 85 <p>If either <var class="var">srcdir</var> or <var class="var">objdir</var> is located on an automounted NFS 86 file system, the shell’s built-in <code class="command">pwd</code> command will return 87 temporary pathnames. Using these can lead to various sorts of build 88 problems. To avoid this issue, set the <code class="env">PWDCMD</code> environment 89 variable to an automounter-aware <code class="command">pwd</code> command, e.g., 90 <code class="command">pawd</code> or ‘<samp class="samp">amq -w</samp>’, during the configuration and build 91 phases. 92 </p> 93 <p>First, we <strong class="strong">highly</strong> recommend that GCC be built into a 94 separate directory from the sources which does <strong class="strong">not</strong> reside 95 within the source tree. This is how we generally build GCC; building 96 where <var class="var">objdir</var> is a subdirectory of <var class="var">srcdir</var> should work as well; 97 building where <var class="var">objdir</var> == <var class="var">srcdir</var> is unsupported. 98 </p> 99 <p>If you have previously built GCC in the same directory for a 100 different target machine, do ‘<samp class="samp">make distclean</samp>’ to delete all files 101 that might be invalid. One of the files this deletes is <samp class="file">Makefile</samp>; 102 if ‘<samp class="samp">make distclean</samp>’ complains that <samp class="file">Makefile</samp> does not exist 103 or issues a message like “don’t know how to make distclean” it probably 104 means that the directory is already suitably clean. However, with the 105 recommended method of building in a separate <var class="var">objdir</var>, you should 106 simply use a different <var class="var">objdir</var> for each target. 107 </p> 108 <p>Second, when configuring a native system, either <code class="command">cc</code> or 109 <code class="command">gcc</code> must be in your path or you must set <code class="env">CC</code> in 110 your environment before running configure. Otherwise the configuration 111 scripts may fail. 112 </p> 113 114 <p>To configure GCC: 115 </p> 116 <div class="example smallexample"> 117 <pre class="example-preformatted">% mkdir <var class="var">objdir</var> 118 % cd <var class="var">objdir</var> 119 % <var class="var">srcdir</var>/configure [<var class="var">options</var>] [<var class="var">target</var>] 120 </pre></div> 121 122 <h3 class="heading" id="Distributor-options"><span>Distributor options<a class="copiable-link" href="#Distributor-options"> ¶</a></span></h3> 123 124 <p>If you will be distributing binary versions of GCC, with modifications 125 to the source code, you should use the options described in this 126 section to make clear that your version contains modifications. 127 </p> 128 <dl class="table"> 129 <dt><code class="code">--with-pkgversion=<var class="var">version</var></code></dt> 130 <dd><p>Specify a string that identifies your package. You may wish 131 to include a build number or build date. This version string will be 132 included in the output of <code class="command">gcc --version</code>. This suffix does 133 not replace the default version string, only the ‘<samp class="samp">GCC</samp>’ part. 134 </p> 135 <p>The default value is ‘<samp class="samp">GCC</samp>’. 136 </p> 137 </dd> 138 <dt><code class="code">--with-bugurl=<var class="var">url</var></code></dt> 139 <dd><p>Specify the URL that users should visit if they wish to report a bug. 140 You are of course welcome to forward bugs reported to you to the FSF, 141 if you determine that they are not bugs in your modifications. 142 </p> 143 <p>The default value refers to the FSF’s GCC bug tracker. 144 </p> 145 </dd> 146 <dt><code class="code">--with-documentation-root-url=<var class="var">url</var></code></dt> 147 <dd><p>Specify the URL root that contains GCC option documentation. The <var class="var">url</var> 148 should end with a <code class="code">/</code> character. 149 </p> 150 <p>The default value is <a class="uref" href="https://gcc.gnu.org/onlinedocs/">https://gcc.gnu.org/onlinedocs/</a> 151 on the GCC main development trunk. On release branches, the default 152 is <code class="code">https://gcc.gnu.org/onlinedocs/gcc-<var class="var">major</var>.<var class="var">minor</var>.0/</code>. 153 </p> 154 </dd> 155 <dt><code class="code">--with-changes-root-url=<var class="var">url</var></code></dt> 156 <dd><p>Specify the URL root that contains information about changes in GCC 157 releases like <code class="code">gcc-<var class="var">version</var>/changes.html</code>. 158 The <var class="var">url</var> should end with a <code class="code">/</code> character. 159 </p> 160 <p>The default value is <a class="uref" href="https://gcc.gnu.org/">https://gcc.gnu.org/</a>. 161 </p> 162 </dd> 163 </dl> 164 165 <h3 class="heading" id="Host_002c-Build-and-Target-specification"><span>Host, Build and Target specification<a class="copiable-link" href="#Host_002c-Build-and-Target-specification"> ¶</a></span></h3> 166 167 <p>Specify the host, build and target machine configurations. You do this 168 when you run the <samp class="file">configure</samp> script. 169 </p> 170 <p>The <em class="dfn">build</em> machine is the system which you are using, the 171 <em class="dfn">host</em> machine is the system where you want to run the resulting 172 compiler (normally the build machine), and the <em class="dfn">target</em> machine is 173 the system for which you want the compiler to generate code. 174 </p> 175 <p>If you are building a compiler to produce code for the machine it runs 176 on (a native compiler), you normally do not need to specify any operands 177 to <samp class="file">configure</samp>; it will try to guess the type of machine you are on 178 and use that as the build, host and target machines. So you don’t need 179 to specify a configuration when building a native compiler unless 180 <samp class="file">configure</samp> cannot figure out what your configuration is or guesses 181 wrong. 182 </p> 183 <p>In those cases, specify the build machine’s <em class="dfn">configuration name</em> 184 with the <samp class="option">--host</samp> option; the host and target will default to be 185 the same as the host machine. 186 </p> 187 <p>Here is an example: 188 </p> 189 <div class="example smallexample"> 190 <pre class="example-preformatted">./configure --host=x86_64-pc-linux-gnu 191 </pre></div> 192 193 <p>A configuration name may be canonical or it may be more or less 194 abbreviated (<samp class="file">config.sub</samp> script produces canonical versions). 195 </p> 196 <p>A canonical configuration name has three parts, separated by dashes. 197 It looks like this: ‘<samp class="samp"><var class="var">cpu</var>-<var class="var">company</var>-<var class="var">system</var></samp>’. 198 </p> 199 <p>Here are the possible CPU types: 200 </p> 201 <blockquote class="quotation"> 202 <p>aarch64, aarch64_be, alpha, alpha64, amdgcn, arc, arceb, arm, armeb, avr, bfin, 203 bpf, cris, csky, epiphany, fido, fr30, frv, ft32, h8300, hppa, hppa2.0, 204 hppa64, i486, i686, ia64, iq2000, lm32, loongarch64, m32c, m32r, m32rle, m68k, 205 mcore, microblaze, microblazeel, mips, mips64, mips64el, mips64octeon, 206 mips64orion, mips64vr, mipsel, mipsisa32, mipsisa32r2, mipsisa64, mipsisa64r2, 207 mipsisa64r2el, mipsisa64sb1, mipsisa64sr71k, mipstx39, mmix, mn10300, moxie, 208 msp430, nds32be, nds32le, nios2, nvptx, or1k, pdp11, powerpc, powerpc64, 209 powerpc64le, powerpcle, pru, riscv32, riscv32be, riscv64, riscv64be, rl78, rx, 210 s390, s390x, sh, shle, sparc, sparc64, tic6x, v850, 211 v850e, v850e1, vax, visium, x86_64, xstormy16, xtensa 212 </p></blockquote> 213 214 <p>Here is a list of system types: 215 </p> 216 <blockquote class="quotation"> 217 <p>aix<var class="var">version</var>, amdhsa, aout, cygwin, darwin<var class="var">version</var>, 218 eabi, eabialtivec, eabisim, eabisimaltivec, elf, elf32, 219 elfbare, elfoabi, freebsd<var class="var">version</var>, gnu, hpux, hpux<var class="var">version</var>, 220 kfreebsd-gnu, kopensolaris-gnu, linux-androideabi, linux-gnu, 221 linux-gnu_altivec, linux-musl, linux-uclibc, lynxos, mingw32, mingw32crt, 222 mmixware, msdosdjgpp, netbsd, netbsdelf<var class="var">version</var>, nto-qnx, openbsd, 223 rtems, solaris<var class="var">version</var>, symbianelf, tpf, uclinux, uclinux_eabi, vms, 224 vxworks, vxworksae, vxworksmils 225 </p></blockquote> 226 227 <h3 class="heading" id="Options-specification"><span>Options specification<a class="copiable-link" href="#Options-specification"> ¶</a></span></h3> 228 229 <p>Use <var class="var">options</var> to override several configure time options for 230 GCC. A list of supported <var class="var">options</var> follows; ‘<samp class="samp">configure 231 --help</samp>’ may list other options, but those not listed below may not 232 work and should not normally be used. 233 </p> 234 <p>Note that each <samp class="option">--enable</samp> option has a corresponding 235 <samp class="option">--disable</samp> option and that each <samp class="option">--with</samp> option has a 236 corresponding <samp class="option">--without</samp> option. 237 </p> 238 <dl class="table"> 239 <dt><code class="code">--prefix=<var class="var">dirname</var></code></dt> 240 <dd><p>Specify the toplevel installation 241 directory. This is the recommended way to install the tools into a directory 242 other than the default. The toplevel installation directory defaults to 243 <samp class="file">/usr/local</samp>. 244 </p> 245 <p>We <strong class="strong">highly</strong> recommend against <var class="var">dirname</var> being the same or a 246 subdirectory of <var class="var">objdir</var> or vice versa. If specifying a directory 247 beneath a user’s home directory tree, some shells will not expand 248 <var class="var">dirname</var> correctly if it contains the ‘<samp class="samp">~</samp>’ metacharacter; use 249 <code class="env">$HOME</code> instead. 250 </p> 251 <p>The following standard <code class="command">autoconf</code> options are supported. Normally you 252 should not need to use these options. 253 </p><dl class="table"> 254 <dt><code class="code">--exec-prefix=<var class="var">dirname</var></code></dt> 255 <dd><p>Specify the toplevel installation directory for architecture-dependent 256 files. The default is <samp class="file"><var class="var">prefix</var></samp>. 257 </p> 258 </dd> 259 <dt><code class="code">--bindir=<var class="var">dirname</var></code></dt> 260 <dd><p>Specify the installation directory for the executables called by users 261 (such as <code class="command">gcc</code> and <code class="command">g++</code>). The default is 262 <samp class="file"><var class="var">exec-prefix</var>/bin</samp>. 263 </p> 264 </dd> 265 <dt><code class="code">--libdir=<var class="var">dirname</var></code></dt> 266 <dd><p>Specify the installation directory for object code libraries and 267 internal data files of GCC. The default is <samp class="file"><var class="var">exec-prefix</var>/lib</samp>. 268 </p> 269 </dd> 270 <dt><code class="code">--libexecdir=<var class="var">dirname</var></code></dt> 271 <dd><p>Specify the installation directory for internal executables of GCC. 272 The default is <samp class="file"><var class="var">exec-prefix</var>/libexec</samp>. 273 </p> 274 </dd> 275 <dt><code class="code">--with-slibdir=<var class="var">dirname</var></code></dt> 276 <dd><p>Specify the installation directory for the shared libgcc library. The 277 default is <samp class="file"><var class="var">libdir</var></samp>. 278 </p> 279 </dd> 280 <dt><code class="code">--datarootdir=<var class="var">dirname</var></code></dt> 281 <dd><p>Specify the root of the directory tree for read-only architecture-independent 282 data files referenced by GCC. The default is <samp class="file"><var class="var">prefix</var>/share</samp>. 283 </p> 284 </dd> 285 <dt><code class="code">--infodir=<var class="var">dirname</var></code></dt> 286 <dd><p>Specify the installation directory for documentation in info format. 287 The default is <samp class="file"><var class="var">datarootdir</var>/info</samp>. 288 </p> 289 </dd> 290 <dt><code class="code">--datadir=<var class="var">dirname</var></code></dt> 291 <dd><p>Specify the installation directory for some architecture-independent 292 data files referenced by GCC. The default is <samp class="file"><var class="var">datarootdir</var></samp>. 293 </p> 294 </dd> 295 <dt><code class="code">--docdir=<var class="var">dirname</var></code></dt> 296 <dd><p>Specify the installation directory for documentation files (other 297 than Info) for GCC. The default is <samp class="file"><var class="var">datarootdir</var>/doc</samp>. 298 </p> 299 </dd> 300 <dt><code class="code">--htmldir=<var class="var">dirname</var></code></dt> 301 <dd><p>Specify the installation directory for HTML documentation files. 302 The default is <samp class="file"><var class="var">docdir</var></samp>. 303 </p> 304 </dd> 305 <dt><code class="code">--pdfdir=<var class="var">dirname</var></code></dt> 306 <dd><p>Specify the installation directory for PDF documentation files. 307 The default is <samp class="file"><var class="var">docdir</var></samp>. 308 </p> 309 </dd> 310 <dt><code class="code">--mandir=<var class="var">dirname</var></code></dt> 311 <dd><p>Specify the installation directory for manual pages. The default is 312 <samp class="file"><var class="var">datarootdir</var>/man</samp>. (Note that the manual pages are only extracts 313 from the full GCC manuals, which are provided in Texinfo format. The manpages 314 are derived by an automatic conversion process from parts of the full 315 manual.) 316 </p> 317 </dd> 318 <dt><code class="code">--with-gxx-include-dir=<var class="var">dirname</var></code></dt> 319 <dd><p>Specify 320 the installation directory for G++ header files. The default depends 321 on other configuration options, and differs between cross and native 322 configurations. 323 </p> 324 </dd> 325 <dt><code class="code">--with-specs=<var class="var">specs</var></code></dt> 326 <dd><p>Specify additional command line driver SPECS. 327 This can be useful if you need to turn on a non-standard feature by 328 default without modifying the compiler’s source code, for instance 329 <samp class="option">--with-specs=%{!fcommon:%{!fno-common:-fno-common}}</samp>. 330 See “Spec Files” in the main manual 331 </p> 332 </dd> 333 </dl> 334 335 </dd> 336 <dt><code class="code">--program-prefix=<var class="var">prefix</var></code></dt> 337 <dd><p>GCC supports some transformations of the names of its programs when 338 installing them. This option prepends <var class="var">prefix</var> to the names of 339 programs to install in <var class="var">bindir</var> (see above). For example, specifying 340 <samp class="option">--program-prefix=foo-</samp> would result in ‘<samp class="samp">gcc</samp>’ 341 being installed as <samp class="file">/usr/local/bin/foo-gcc</samp>. 342 </p> 343 </dd> 344 <dt><code class="code">--program-suffix=<var class="var">suffix</var></code></dt> 345 <dd><p>Appends <var class="var">suffix</var> to the names of programs to install in <var class="var">bindir</var> 346 (see above). For example, specifying <samp class="option">--program-suffix=-3.1</samp> 347 would result in ‘<samp class="samp">gcc</samp>’ being installed as 348 <samp class="file">/usr/local/bin/gcc-3.1</samp>. 349 </p> 350 </dd> 351 <dt><code class="code">--program-transform-name=<var class="var">pattern</var></code></dt> 352 <dd><p>Applies the ‘<samp class="samp">sed</samp>’ script <var class="var">pattern</var> to be applied to the names 353 of programs to install in <var class="var">bindir</var> (see above). <var class="var">pattern</var> has to 354 consist of one or more basic ‘<samp class="samp">sed</samp>’ editing commands, separated by 355 semicolons. For example, if you want the ‘<samp class="samp">gcc</samp>’ program name to be 356 transformed to the installed program <samp class="file">/usr/local/bin/myowngcc</samp> and 357 the ‘<samp class="samp">g++</samp>’ program name to be transformed to 358 <samp class="file">/usr/local/bin/gspecial++</samp> without changing other program names, 359 you could use the pattern 360 <samp class="option">--program-transform-name='s/^gcc$/myowngcc/; s/^g++$/gspecial++/'</samp> 361 to achieve this effect. 362 </p> 363 <p>All three options can be combined and used together, resulting in more 364 complex conversion patterns. As a basic rule, <var class="var">prefix</var> (and 365 <var class="var">suffix</var>) are prepended (appended) before further transformations 366 can happen with a special transformation script <var class="var">pattern</var>. 367 </p> 368 <p>As currently implemented, this option only takes effect for native 369 builds; cross compiler binaries’ names are not transformed even when a 370 transformation is explicitly asked for by one of these options. 371 </p> 372 <p>For native builds, some of the installed programs are also installed 373 with the target alias in front of their name, as in 374 ‘<samp class="samp">i686-pc-linux-gnu-gcc</samp>’. All of the above transformations happen 375 before the target alias is prepended to the name—so, specifying 376 <samp class="option">--program-prefix=foo-</samp> and <samp class="option">program-suffix=-3.1</samp>, the 377 resulting binary would be installed as 378 <samp class="file">/usr/local/bin/i686-pc-linux-gnu-foo-gcc-3.1</samp>. 379 </p> 380 <p>As a last shortcoming, none of the installed Ada programs are 381 transformed yet, which will be fixed in some time. 382 </p> 383 </dd> 384 <dt><code class="code">--with-local-prefix=<var class="var">dirname</var></code></dt> 385 <dd><p>Specify the 386 installation directory for local include files. The default is 387 <samp class="file">/usr/local</samp>. Specify this option if you want the compiler to 388 search directory <samp class="file"><var class="var">dirname</var>/include</samp> for locally installed 389 header files <em class="emph">instead</em> of <samp class="file">/usr/local/include</samp>. 390 </p> 391 <p>You should specify <samp class="option">--with-local-prefix</samp> <strong class="strong">only</strong> if your 392 site has a different convention (not <samp class="file">/usr/local</samp>) for where to put 393 site-specific files. 394 </p> 395 <p>The default value for <samp class="option">--with-local-prefix</samp> is <samp class="file">/usr/local</samp> 396 regardless of the value of <samp class="option">--prefix</samp>. Specifying 397 <samp class="option">--prefix</samp> has no effect on which directory GCC searches for 398 local header files. This may seem counterintuitive, but actually it is 399 logical. 400 </p> 401 <p>The purpose of <samp class="option">--prefix</samp> is to specify where to <em class="emph">install 402 GCC</em>. The local header files in <samp class="file">/usr/local/include</samp>—if you put 403 any in that directory—are not part of GCC. They are part of other 404 programs—perhaps many others. (GCC installs its own header files in 405 another directory which is based on the <samp class="option">--prefix</samp> value.) 406 </p> 407 <p>Both the local-prefix include directory and the GCC-prefix include 408 directory are part of GCC’s “system include” directories. Although these 409 two directories are not fixed, they need to be searched in the proper 410 order for the correct processing of the include_next directive. The 411 local-prefix include directory is searched before the GCC-prefix 412 include directory. Another characteristic of system include directories 413 is that pedantic warnings are turned off for headers in these directories. 414 </p> 415 <p>Some autoconf macros add <samp class="option">-I <var class="var">directory</var></samp> options to the 416 compiler command line, to ensure that directories containing installed 417 packages’ headers are searched. When <var class="var">directory</var> is one of GCC’s 418 system include directories, GCC will ignore the option so that system 419 directories continue to be processed in the correct order. This 420 may result in a search order different from what was specified but the 421 directory will still be searched. 422 </p> 423 <p>GCC automatically searches for ordinary libraries using 424 <code class="env">GCC_EXEC_PREFIX</code>. Thus, when the same installation prefix is 425 used for both GCC and packages, GCC will automatically search for 426 both headers and libraries. This provides a configuration that is 427 easy to use. GCC behaves in a manner similar to that when it is 428 installed as a system compiler in <samp class="file">/usr</samp>. 429 </p> 430 <p>Sites that need to install multiple versions of GCC may not want to 431 use the above simple configuration. It is possible to use the 432 <samp class="option">--program-prefix</samp>, <samp class="option">--program-suffix</samp> and 433 <samp class="option">--program-transform-name</samp> options to install multiple versions 434 into a single directory, but it may be simpler to use different prefixes 435 and the <samp class="option">--with-local-prefix</samp> option to specify the location of the 436 site-specific files for each version. It will then be necessary for 437 users to specify explicitly the location of local site libraries 438 (e.g., with <code class="env">LIBRARY_PATH</code>). 439 </p> 440 <p>The same value can be used for both <samp class="option">--with-local-prefix</samp> and 441 <samp class="option">--prefix</samp> provided it is not <samp class="file">/usr</samp>. This can be used 442 to avoid the default search of <samp class="file">/usr/local/include</samp>. 443 </p> 444 <p><strong class="strong">Do not</strong> specify <samp class="file">/usr</samp> as the <samp class="option">--with-local-prefix</samp>! 445 The directory you use for <samp class="option">--with-local-prefix</samp> <strong class="strong">must not</strong> 446 contain any of the system’s standard header files. If it did contain 447 them, certain programs would be miscompiled (including GNU Emacs, on 448 certain targets), because this would override and nullify the header 449 file corrections made by the <code class="command">fixincludes</code> script. 450 </p> 451 <p>Indications are that people who use this option use it based on mistaken 452 ideas of what it is for. People use it as if it specified where to 453 install part of GCC. Perhaps they make this assumption because 454 installing GCC creates the directory. 455 </p> 456 </dd> 457 <dt><code class="code">--with-gcc-major-version-only</code></dt> 458 <dd><p>Specifies that GCC should use only the major number rather than 459 <var class="var">major</var>.<var class="var">minor</var>.<var class="var">patchlevel</var> in filesystem paths. 460 </p> 461 </dd> 462 <dt><code class="code">--with-native-system-header-dir=<var class="var">dirname</var></code></dt> 463 <dd><p>Specifies that <var class="var">dirname</var> is the directory that contains native system 464 header files, rather than <samp class="file">/usr/include</samp>. This option is most useful 465 if you are creating a compiler that should be isolated from the system 466 as much as possible. It is most commonly used with the 467 <samp class="option">--with-sysroot</samp> option and will cause GCC to search 468 <var class="var">dirname</var> inside the system root specified by that option. 469 </p> 470 </dd> 471 <dt><code class="code">--enable-shared[=<var class="var">package</var>[,…]]</code></dt> 472 <dd><p>Build shared versions of libraries, if shared libraries are supported on 473 the target platform. Unlike GCC 2.95.x and earlier, shared libraries 474 are enabled by default on all platforms that support shared libraries. 475 </p> 476 <p>If a list of packages is given as an argument, build shared libraries 477 only for the listed packages. For other packages, only static libraries 478 will be built. Package names currently recognized in the GCC tree are 479 ‘<samp class="samp">libgcc</samp>’ (also known as ‘<samp class="samp">gcc</samp>’), ‘<samp class="samp">libstdc++</samp>’ (not 480 ‘<samp class="samp">libstdc++-v3</samp>’), ‘<samp class="samp">libffi</samp>’, ‘<samp class="samp">zlib</samp>’, ‘<samp class="samp">boehm-gc</samp>’, 481 ‘<samp class="samp">ada</samp>’, ‘<samp class="samp">libada</samp>’, ‘<samp class="samp">libgo</samp>’, ‘<samp class="samp">libobjc</samp>’, and ‘<samp class="samp">libphobos</samp>’. 482 Note ‘<samp class="samp">libiberty</samp>’ does not support shared libraries at all. 483 </p> 484 <p>Use <samp class="option">--disable-shared</samp> to build only static libraries. Note that 485 <samp class="option">--disable-shared</samp> does not accept a list of package names as 486 argument, only <samp class="option">--enable-shared</samp> does. 487 </p> 488 <p>Contrast with <samp class="option">--enable-host-shared</samp>, which affects <em class="emph">host</em> 489 code. 490 </p> 491 </dd> 492 <dt><code class="code">--enable-host-shared</code></dt> 493 <dd><p>Specify that the <em class="emph">host</em> code should be built into position-independent 494 machine code (with <samp class="option">-fPIC</samp>), allowing it to be used within shared 495 libraries, but yielding a slightly slower compiler. 496 </p> 497 <p>This option is required when building the libgccjit.so library. 498 </p> 499 <p>Contrast with <samp class="option">--enable-shared</samp>, which affects <em class="emph">target</em> 500 libraries. 501 </p> 502 </dd> 503 <dt><code class="code">--enable-host-pie</code></dt> 504 <dd><p>Specify that the <em class="emph">host</em> executables should be built into 505 position-independent executables (with <samp class="option">-fPIE</samp> and <samp class="option">-pie</samp>), 506 yielding a slightly slower compiler (but faster than 507 <samp class="option">--enable-host-shared</samp>). Position-independent executables are loaded 508 at random addresses each time they are executed, therefore provide additional 509 protection against Return Oriented Programming (ROP) attacks. 510 </p> 511 <p><samp class="option">--enable-host-pie</samp> may be used with <samp class="option">--enable-host-shared</samp>, 512 in which case <samp class="option">-fPIC</samp> is used when compiling, and <samp class="option">-pie</samp> when 513 linking. 514 </p> 515 </dd> 516 <dt><code class="code">--enable-host-bind-now</code></dt> 517 <dd><p>Specify that the <em class="emph">host</em> executables should be linked with the option 518 <samp class="option">-Wl,-z,now</samp>, which means that the dynamic linker will resolve all 519 symbols when the executables are started, and that in turn allows RELRO to 520 mark the GOT read-only, resulting in better security. 521 </p> 522 </dd> 523 <dt><code class="code"><a class="anchor" id="with-gnu-as"></a>--with-gnu-as</code></dt> 524 <dd><p>Specify that the compiler should assume that the 525 assembler it finds is the GNU assembler. However, this does not modify 526 the rules to find an assembler and will result in confusion if the 527 assembler found is not actually the GNU assembler. (Confusion may also 528 result if the compiler finds the GNU assembler but has not been 529 configured with <samp class="option">--with-gnu-as</samp>.) If you have more than one 530 assembler installed on your system, you may want to use this option in 531 connection with <samp class="option">--with-as=<var class="var">pathname</var></samp> or 532 <samp class="option">--with-build-time-tools=<var class="var">pathname</var></samp>. 533 </p> 534 <p>The following systems are the only ones where it makes a difference 535 whether you use the GNU assembler. On any other system, 536 <samp class="option">--with-gnu-as</samp> has no effect. 537 </p> 538 <ul class="itemize mark-bullet"> 539 <li>‘<samp class="samp">hppa1.0-<var class="var">any</var>-<var class="var">any</var></samp>’ 540 </li><li>‘<samp class="samp">hppa1.1-<var class="var">any</var>-<var class="var">any</var></samp>’ 541 </li><li>‘<samp class="samp">*-*-solaris2.11</samp>’ 542 </li></ul> 543 544 </dd> 545 <dt><code class="code"><a class="anchor" id="with-as"></a>--with-as=<var class="var">pathname</var></code></dt> 546 <dd><p>Specify that the compiler should use the assembler pointed to by 547 <var class="var">pathname</var>, rather than the one found by the standard rules to find 548 an assembler, which are: 549 </p><ul class="itemize mark-bullet"> 550 <li>Unless GCC is being built with a cross compiler, check the 551 <samp class="file"><var class="var">libexec</var>/gcc/<var class="var">target</var>/<var class="var">version</var></samp> directory. 552 <var class="var">libexec</var> defaults to <samp class="file"><var class="var">exec-prefix</var>/libexec</samp>; 553 <var class="var">exec-prefix</var> defaults to <var class="var">prefix</var>, which 554 defaults to <samp class="file">/usr/local</samp> unless overridden by the 555 <samp class="option">--prefix=<var class="var">pathname</var></samp> switch described above. <var class="var">target</var> 556 is the target system triple, such as ‘<samp class="samp">sparc-sun-solaris2.11</samp>’, and 557 <var class="var">version</var> denotes the GCC version, such as 3.0. 558 559 </li><li>If the target system is the same that you are building on, check 560 operating system specific directories. 561 562 </li><li>Check in the <code class="env">PATH</code> for a tool whose name is prefixed by the 563 target system triple. 564 565 </li><li>Check in the <code class="env">PATH</code> for a tool whose name is not prefixed by the 566 target system triple, if the host and target system triple are 567 the same (in other words, we use a host tool if it can be used for 568 the target as well). 569 </li></ul> 570 571 <p>You may want to use <samp class="option">--with-as</samp> if no assembler 572 is installed in the directories listed above, or if you have multiple 573 assemblers installed and want to choose one that is not found by the 574 above rules. 575 </p> 576 </dd> 577 <dt><code class="code"><a class="anchor" id="with-gnu-ld"></a>--with-gnu-ld</code></dt> 578 <dd><p>Same as <a class="uref" href="#with-gnu-as"><samp class="option">--with-gnu-as</samp></a> 579 but for the linker. 580 </p> 581 </dd> 582 <dt><code class="code">--with-ld=<var class="var">pathname</var></code></dt> 583 <dd><p>Same as <a class="uref" href="#with-as"><samp class="option">--with-as</samp></a> 584 but for the linker. 585 </p> 586 </dd> 587 <dt><code class="code">--with-dsymutil=<var class="var">pathname</var></code></dt> 588 <dd><p>Same as <a class="uref" href="#with-as"><samp class="option">--with-as</samp></a> 589 but for the debug linker (only used on Darwin platforms so far). 590 </p> 591 </dd> 592 <dt><code class="code">--with-tls=<var class="var">dialect</var></code></dt> 593 <dd><p>Specify the default TLS dialect, for systems where there is a choice. 594 For ARM targets, possible values for <var class="var">dialect</var> are <code class="code">gnu</code> or 595 <code class="code">gnu2</code>, which select between the original GNU dialect and the GNU TLS 596 descriptor-based dialect. 597 For RISC-V targets, possible values for <var class="var">dialect</var> are <code class="code">trad</code> or 598 <code class="code">desc</code>, which select between the traditional GNU dialect and the GNU TLS 599 descriptor-based dialect. 600 </p> 601 </dd> 602 <dt><code class="code">--enable-multiarch</code></dt> 603 <dd><p>Specify whether to enable or disable multiarch support. The default is 604 to check for glibc start files in a multiarch location, and enable it 605 if the files are found. The auto detection is enabled for native builds, 606 and for cross builds configured with <samp class="option">--with-sysroot</samp>, and without 607 <samp class="option">--with-native-system-header-dir</samp>. 608 More documentation about multiarch can be found at 609 <a class="uref" href="https://wiki.debian.org/Multiarch">https://wiki.debian.org/Multiarch</a>. 610 </p> 611 </dd> 612 <dt><code class="code">--enable-sjlj-exceptions</code></dt> 613 <dd><p>Force use of the <code class="code">setjmp</code>/<code class="code">longjmp</code>-based scheme for exceptions. 614 ‘<samp class="samp">configure</samp>’ ordinarily picks the correct value based on the platform. 615 Only use this option if you are sure you need a different setting. 616 </p> 617 </dd> 618 <dt><code class="code">--enable-vtable-verify</code></dt> 619 <dd><p>Specify whether to enable or disable the vtable verification feature. 620 Enabling this feature causes libstdc++ to be built with its virtual calls 621 in verifiable mode. This means that, when linked with libvtv, every 622 virtual call in libstdc++ will verify the vtable pointer through which the 623 call will be made before actually making the call. If not linked with libvtv, 624 the verifier will call stub functions (in libstdc++ itself) and do nothing. 625 If vtable verification is disabled, then libstdc++ is not built with its 626 virtual calls in verifiable mode at all. However the libvtv library will 627 still be built (see <samp class="option">--disable-libvtv</samp> to turn off building libvtv). 628 <samp class="option">--disable-vtable-verify</samp> is the default. 629 </p> 630 </dd> 631 <dt><code class="code">--disable-gcov</code></dt> 632 <dd><p>Specify that the run-time library used for coverage analysis 633 and associated host tools should not be built. 634 </p> 635 </dd> 636 <dt><code class="code">--disable-multilib</code></dt> 637 <dd><p>Specify that multiple target 638 libraries to support different target variants, calling 639 conventions, etc. should not be built. The default is to build a 640 predefined set of them. 641 </p> 642 <p>Some targets provide finer-grained control over which multilibs are built 643 (e.g., <samp class="option">--disable-softfloat</samp>): 644 </p><dl class="table"> 645 <dt><code class="code">arm-*-*</code></dt> 646 <dd><p>fpu, 26bit, underscore, interwork, biendian, nofmult. 647 </p> 648 </dd> 649 <dt><code class="code">m68*-*-*</code></dt> 650 <dd><p>softfloat, m68881, m68000, m68020. 651 </p> 652 </dd> 653 <dt><code class="code">mips*-*-*</code></dt> 654 <dd><p>single-float, biendian, softfloat. 655 </p> 656 </dd> 657 <dt><code class="code">msp430-*-*</code></dt> 658 <dd><p>no-exceptions 659 </p> 660 </dd> 661 <dt><code class="code">powerpc*-*-*, rs6000*-*-*</code></dt> 662 <dd><p>aix64, pthread, softfloat, powercpu, powerpccpu, powerpcos, biendian, 663 sysv, aix. 664 </p> 665 </dd> 666 </dl> 667 668 </dd> 669 <dt><code class="code">--with-multilib-list=<var class="var">list</var></code></dt> 670 <dt><code class="code">--without-multilib-list</code></dt> 671 <dd><p>Specify what multilibs to build. <var class="var">list</var> is a comma separated list of 672 values, possibly consisting of a single value. Currently only implemented 673 for aarch64*-*-*, amdgcn*-*-*, arm*-*-*, loongarch*-*-*, riscv*-*-*, sh*-*-* 674 and x86-64-*-linux*. The accepted values and meaning for each target is given 675 below. 676 </p> 677 <dl class="table"> 678 <dt><code class="code">aarch64*-*-*</code></dt> 679 <dd><p><var class="var">list</var> is a comma separated list of <code class="code">ilp32</code>, and <code class="code">lp64</code> 680 to enable ILP32 and LP64 run-time libraries, respectively. If 681 <var class="var">list</var> is empty, then there will be no multilibs and only the 682 default run-time library will be built. If <var class="var">list</var> is 683 <code class="code">default</code> or –with-multilib-list= is not specified, then the 684 default set of libraries is selected based on the value of 685 <samp class="option">--target</samp>. 686 </p> 687 </dd> 688 <dt><code class="code">amdgcn*-*-*</code></dt> 689 <dd><p><var class="var">list</var> is a comma separated list of ISA names (allowed values: <code class="code">fiji</code>, 690 <code class="code">gfx900</code>, <code class="code">gfx906</code>, <code class="code">gfx908</code>, <code class="code">gfx90a</code>, <code class="code">gfx90c</code>, 691 <code class="code">gfx1030</code>, <code class="code">gfx1036</code>, <code class="code">gfx1100</code>, <code class="code">gfx1103</code>). 692 It ought not include the name of the default 693 ISA, specified via <samp class="option">--with-arch</samp>. If <var class="var">list</var> is empty, then there 694 will be no multilibs and only the default run-time library will be built. If 695 <var class="var">list</var> is <code class="code">default</code> or <samp class="option">--with-multilib-list=</samp> is not 696 specified, then the default set of libraries is selected. 697 </p> 698 </dd> 699 <dt><code class="code">arm*-*-*</code></dt> 700 <dd><p><var class="var">list</var> is a comma separated list of <code class="code">aprofile</code> and 701 <code class="code">rmprofile</code> to build multilibs for A or R and M architecture 702 profiles respectively. Note that, due to some limitation of the current 703 multilib framework, using the combined <code class="code">aprofile,rmprofile</code> 704 multilibs selects in some cases a less optimal multilib than when using 705 the multilib profile for the architecture targetted. The special value 706 <code class="code">default</code> is also accepted and is equivalent to omitting the 707 option, i.e., only the default run-time library will be enabled. 708 </p> 709 <p><var class="var">list</var> may instead contain <code class="code">@name</code>, to use the multilib 710 configuration Makefile fragment <samp class="file">name</samp> in <samp class="file">gcc/config/arm</samp> in 711 the source tree (it is part of the corresponding sources, after all). 712 It is recommended, but not required, that files used for this purpose to 713 be named starting with <samp class="file">t-ml-</samp>, to make their intended purpose 714 self-evident, in line with GCC conventions. Such files enable custom, 715 user-chosen multilib lists to be configured. Whether multiple such 716 files can be used together depends on the contents of the supplied 717 files. See <samp class="file">gcc/config/arm/t-multilib</samp> and its supplementary 718 <samp class="file">gcc/config/arm/t-*profile</samp> files for an example of what such 719 Makefile fragments might look like for this version of GCC. The macros 720 expected to be defined in these fragments are not stable across GCC 721 releases, so make sure they define the <code class="code">MULTILIB</code>-related macros 722 expected by the version of GCC you are building. 723 See “Target Makefile Fragments” in the internals manual. 724 </p> 725 <p>The table below gives the combination of ISAs, architectures, FPUs and 726 floating-point ABIs for which multilibs are built for each predefined 727 profile. The union of these options is considered when specifying both 728 <code class="code">aprofile</code> and <code class="code">rmprofile</code>. 729 </p> 730 <table class="multitable"> 731 <tbody><tr><td width="15%">Option</td><td width="28%">aprofile</td><td width="30%">rmprofile</td></tr> 732 <tr><td width="15%">ISAs</td><td width="28%"><code class="code">-marm</code> and <code class="code">-mthumb</code></td><td width="30%"><code class="code">-mthumb</code></td></tr> 733 <tr><td width="15%">Architectures<br><br><br><br><br><br></td><td width="28%">default architecture<br> 734 <code class="code">-march=armv7-a</code><br> 735 <code class="code">-march=armv7ve</code><br> 736 <code class="code">-march=armv8-a</code><br><br><br></td><td width="30%">default architecture<br> 737 <code class="code">-march=armv6s-m</code><br> 738 <code class="code">-march=armv7-m</code><br> 739 <code class="code">-march=armv7e-m</code><br> 740 <code class="code">-march=armv8-m.base</code><br> 741 <code class="code">-march=armv8-m.main</code><br> 742 <code class="code">-march=armv7</code></td></tr> 743 <tr><td width="15%">FPUs<br><br><br><br><br></td><td width="28%">none<br> 744 <code class="code">-mfpu=vfpv3-d16</code><br> 745 <code class="code">-mfpu=neon</code><br> 746 <code class="code">-mfpu=vfpv4-d16</code><br> 747 <code class="code">-mfpu=neon-vfpv4</code><br> 748 <code class="code">-mfpu=neon-fp-armv8</code></td><td width="30%">none<br> 749 <code class="code">-mfpu=vfpv3-d16</code><br> 750 <code class="code">-mfpu=fpv4-sp-d16</code><br> 751 <code class="code">-mfpu=fpv5-sp-d16</code><br> 752 <code class="code">-mfpu=fpv5-d16</code><br></td></tr> 753 <tr><td width="15%">floating-point ABIs<br><br></td><td width="28%"><code class="code">-mfloat-abi=soft</code><br> 754 <code class="code">-mfloat-abi=softfp</code><br> 755 <code class="code">-mfloat-abi=hard</code></td><td width="30%"><code class="code">-mfloat-abi=soft</code><br> 756 <code class="code">-mfloat-abi=softfp</code><br> 757 <code class="code">-mfloat-abi=hard</code></td></tr> 758 </tbody> 759 </table> 760 761 </dd> 762 <dt><code class="code">loongarch*-*-*</code></dt> 763 <dd><p><var class="var">list</var> is a comma-separated list, with each of the element starting with 764 the following ABI identifiers: <code class="code">lp64d[/base]</code> <code class="code">lp64f[/base]</code> 765 <code class="code">lp64d[/base]</code> (the <code class="code">/base</code> suffix may be omitted) 766 to enable their respective run-time libraries. 767 </p> 768 <p>A suffix <code class="code">[/<var class="var">arch</var>][/<var class="var">option</var>/…]</code> may follow immediately 769 after the ABI identifier to customize the compiler options for building the 770 given set of libraries. <var class="var">arch</var> denotes the architecture name recognized 771 by the <samp class="option">-march=<var class="var">arch</var></samp> compiler option, which acts as a basic target 772 ISA configuration that can be adjusted using the subsequent <var class="var">option</var> 773 suffixes, where each <var class="var">option</var> is a compiler option without a leading dash 774 (’-’). 775 </p> 776 <p>If no such suffix is present for a given multilib variant, the 777 configured value of <samp class="option">--with-multilib-default</samp> is appended as a default 778 suffix. If <samp class="option">--with-multilib-default</samp> is not given, the default build 779 option <samp class="option">-march=abi-default</samp> is applied when building the variants 780 without a suffix. 781 </p> 782 <p>As a special case, <code class="code">fixed</code> may be used in the position of <var class="var">arch</var>, 783 which means using the architecture configured with 784 <samp class="option">--with-arch=<var class="var">arch</var></samp>, or its default value (e.g. <code class="code">loongarch64</code> 785 for <code class="code">loongarch64-*</code> targets). 786 </p> 787 <p>If <var class="var">list</var> is empty or <code class="code">default</code>, or if <samp class="option">--with-multilib-list</samp> 788 is not specified, then only the default variant of the libraries are built, 789 where the default ABI is implied by the configured target triplet. 790 </p> 791 </dd> 792 <dt><code class="code">riscv*-*-*</code></dt> 793 <dd><p><var class="var">list</var> is a single ABI name. The target architecture must be either 794 <code class="code">rv32gc</code> or <code class="code">rv64gc</code>. This will build a single multilib for the 795 specified architecture and ABI pair. If <code class="code">--with-multilib-list</code> is not 796 given, then a default set of multilibs is selected based on the value of 797 <samp class="option">--target</samp>. This is usually a large set of multilibs. 798 </p> 799 </dd> 800 <dt><code class="code">sh*-*-*</code></dt> 801 <dd><p><var class="var">list</var> is a comma separated list of CPU names. These must be of the 802 form <code class="code">sh*</code> or <code class="code">m*</code> (in which case they match the compiler option 803 for that processor). The list should not contain any endian options - 804 these are handled by <samp class="option">--with-endian</samp>. 805 </p> 806 <p>If <var class="var">list</var> is empty, then there will be no multilibs for extra 807 processors. The multilib for the secondary endian remains enabled. 808 </p> 809 <p>As a special case, if an entry in the list starts with a <code class="code">!</code> 810 (exclamation point), then it is added to the list of excluded multilibs. 811 Entries of this sort should be compatible with ‘<samp class="samp">MULTILIB_EXCLUDES</samp>’ 812 (once the leading <code class="code">!</code> has been stripped). 813 </p> 814 <p>If <samp class="option">--with-multilib-list</samp> is not given, then a default set of 815 multilibs is selected based on the value of <samp class="option">--target</samp>. This is 816 usually the complete set of libraries, but some targets imply a more 817 specialized subset. 818 </p> 819 <p>Example 1: to configure a compiler for SH4A only, but supporting both 820 endians, with little endian being the default: 821 </p><div class="example smallexample"> 822 <pre class="example-preformatted">--with-cpu=sh4a --with-endian=little,big --with-multilib-list= 823 </pre></div> 824 825 <p>Example 2: to configure a compiler for both SH4A and SH4AL-DSP, but with 826 only little endian SH4AL: 827 </p><div class="example smallexample"> 828 <pre class="example-preformatted">--with-cpu=sh4a --with-endian=little,big \ 829 --with-multilib-list=sh4al,!mb/m4al 830 </pre></div> 831 832 </dd> 833 <dt><code class="code">x86-64-*-linux*</code></dt> 834 <dd><p><var class="var">list</var> is a comma separated list of <code class="code">m32</code>, <code class="code">m64</code> and 835 <code class="code">mx32</code> to enable 32-bit, 64-bit and x32 run-time libraries, 836 respectively. If <var class="var">list</var> is empty, then there will be no multilibs 837 and only the default run-time library will be enabled. 838 </p> 839 <p>If <samp class="option">--with-multilib-list</samp> is not given, then only 32-bit and 840 64-bit run-time libraries will be enabled. 841 </p></dd> 842 </dl> 843 844 </dd> 845 <dt><code class="code">--with-multilib-default</code></dt> 846 <dd><p>On LoongArch targets, set the default build options for enabled multilibs 847 without build options appended to their corresponding 848 <samp class="option">--with-multilib-list</samp> items. The format of this value is 849 <code class="code">[/<var class="var">arch</var>][/<var class="var">option</var>/…]</code>, where <var class="var">arch</var> is an 850 architecture name recognized by <samp class="option">-march=<var class="var">arch</var></samp> compiler option, 851 and subsequent <var class="var">option</var> suffixes are compiler options minus a leading 852 dash (’-’). 853 </p> 854 <p>Multiple <var class="var">option</var>s may appear consecutively while <var class="var">arch</var> may only 855 appear in the beginning or be omitted (which means <samp class="option">-march=abi-default</samp> 856 is applied when building the libraries). 857 </p> 858 </dd> 859 <dt><code class="code">--with-strict-align-lib</code></dt> 860 <dd><p>On LoongArch targets, build all enabled multilibs with <samp class="option">-mstrict-align</samp> 861 (Not enabled by default). 862 </p> 863 </dd> 864 <dt><code class="code">--with-multilib-generator=<var class="var">config</var></code></dt> 865 <dd><p>Specify what multilibs to build. <var class="var">config</var> is a semicolon separated list of 866 values, possibly consisting of a single value. Currently only implemented 867 for riscv*-*-elf*. The accepted values and meanings are given below. 868 </p> 869 870 <p>Every config is constructed with four components: architecture string, ABI, 871 reuse rule with architecture string and reuse rule with sub-extension. 872 </p> 873 <p>Example 1: Add multi-lib suppport for rv32i with ilp32. 874 </p><div class="example smallexample"> 875 <pre class="example-preformatted">rv32i-ilp32-- 876 </pre></div> 877 878 <p>Example 2: Add multi-lib suppport for rv32i with ilp32 and rv32imafd with ilp32. 879 </p><div class="example smallexample"> 880 <pre class="example-preformatted">rv32i-ilp32--;rv32imafd-ilp32-- 881 </pre></div> 882 883 <p>Example 3: Add multi-lib suppport for rv32i with ilp32; rv32im with ilp32 and 884 rv32ic with ilp32 will reuse this multi-lib set. 885 </p><div class="example smallexample"> 886 <pre class="example-preformatted">rv32i-ilp32-rv32im-c 887 </pre></div> 888 889 <p>Example 4: Add multi-lib suppport for rv64ima with lp64; rv64imaf with lp64, 890 rv64imac with lp64 and rv64imafc with lp64 will reuse this multi-lib set. 891 </p><div class="example smallexample"> 892 <pre class="example-preformatted">rv64ima-lp64--f,c,fc 893 </pre></div> 894 895 <p><samp class="option">--with-multilib-generator</samp> have an optional configuration argument 896 <samp class="option">--cmodel=val</samp> for code model, this option will expand with other 897 config options, <var class="var">val</var> is a comma separated list of possible code model, 898 currently we support medlow and medany. 899 </p> 900 <p>Example 5: Add multi-lib suppport for rv64ima with lp64; rv64ima with lp64 and 901 medlow code model 902 </p><div class="example smallexample"> 903 <pre class="example-preformatted">rv64ima-lp64--;--cmodel=medlow 904 </pre></div> 905 906 <p>Example 6: Add multi-lib suppport for rv64ima with lp64; rv64ima with lp64 and 907 medlow code model; rv64ima with lp64 and medany code model 908 </p><div class="example smallexample"> 909 <pre class="example-preformatted">rv64ima-lp64--;--cmodel=medlow,medany 910 </pre></div> 911 912 </dd> 913 <dt><code class="code">--with-endian=<var class="var">endians</var></code></dt> 914 <dd><p>Specify what endians to use. 915 Currently only implemented for sh*-*-*. 916 </p> 917 <p><var class="var">endians</var> may be one of the following: 918 </p><dl class="table"> 919 <dt><code class="code">big</code></dt> 920 <dd><p>Use big endian exclusively. 921 </p></dd> 922 <dt><code class="code">little</code></dt> 923 <dd><p>Use little endian exclusively. 924 </p></dd> 925 <dt><code class="code">big,little</code></dt> 926 <dd><p>Use big endian by default. Provide a multilib for little endian. 927 </p></dd> 928 <dt><code class="code">little,big</code></dt> 929 <dd><p>Use little endian by default. Provide a multilib for big endian. 930 </p></dd> 931 </dl> 932 933 </dd> 934 <dt><code class="code">--enable-threads</code></dt> 935 <dd><p>Specify that the target 936 supports threads. This affects the Objective-C compiler and runtime 937 library, and exception handling for other languages like C++. 938 On some systems, this is the default. 939 </p> 940 <p>In general, the best (and, in many cases, the only known) threading 941 model available will be configured for use. Beware that on some 942 systems, GCC has not been taught what threading models are generally 943 available for the system. In this case, <samp class="option">--enable-threads</samp> is an 944 alias for <samp class="option">--enable-threads=single</samp>. 945 </p> 946 </dd> 947 <dt><code class="code">--disable-threads</code></dt> 948 <dd><p>Specify that threading support should be disabled for the system. 949 This is an alias for <samp class="option">--enable-threads=single</samp>. 950 </p> 951 </dd> 952 <dt><code class="code">--enable-threads=<var class="var">lib</var></code></dt> 953 <dd><p>Specify that 954 <var class="var">lib</var> is the thread support library. This affects the Objective-C 955 compiler and runtime library, and exception handling for other languages 956 like C++. The possibilities for <var class="var">lib</var> are: 957 </p> 958 <dl class="table"> 959 <dt><code class="code">aix</code></dt> 960 <dd><p>AIX thread support. 961 </p></dd> 962 <dt><code class="code">dce</code></dt> 963 <dd><p>DCE thread support. 964 </p></dd> 965 <dt><code class="code">lynx</code></dt> 966 <dd><p>LynxOS thread support. 967 </p></dd> 968 <dt><code class="code">mipssde</code></dt> 969 <dd><p>MIPS SDE thread support. 970 </p></dd> 971 <dt><code class="code">no</code></dt> 972 <dd><p>This is an alias for ‘<samp class="samp">single</samp>’. 973 </p></dd> 974 <dt><code class="code">posix</code></dt> 975 <dd><p>Generic POSIX/Unix98 thread support. 976 </p></dd> 977 <dt><code class="code">rtems</code></dt> 978 <dd><p>RTEMS thread support. 979 </p></dd> 980 <dt><code class="code">single</code></dt> 981 <dd><p>Disable thread support, should work for all platforms. 982 </p></dd> 983 <dt><code class="code">tpf</code></dt> 984 <dd><p>TPF thread support. 985 </p></dd> 986 <dt><code class="code">vxworks</code></dt> 987 <dd><p>VxWorks thread support. 988 </p></dd> 989 <dt><code class="code">win32</code></dt> 990 <dd><p>Microsoft Win32 API thread support. 991 </p></dd> 992 </dl> 993 994 </dd> 995 <dt><code class="code">--enable-tls</code></dt> 996 <dd><p>Specify that the target supports TLS (Thread Local Storage). Usually 997 configure can correctly determine if TLS is supported. In cases where 998 it guesses incorrectly, TLS can be explicitly enabled or disabled with 999 <samp class="option">--enable-tls</samp> or <samp class="option">--disable-tls</samp>. This can happen if 1000 the assembler supports TLS but the C library does not, or if the 1001 assumptions made by the configure test are incorrect. 1002 </p> 1003 </dd> 1004 <dt><code class="code">--disable-tls</code></dt> 1005 <dd><p>Specify that the target does not support TLS. 1006 This is an alias for <samp class="option">--enable-tls=no</samp>. 1007 </p> 1008 </dd> 1009 <dt><code class="code">--disable-tm-clone-registry</code></dt> 1010 <dd><p>Disable TM clone registry in libgcc. It is enabled in libgcc by default. 1011 This option helps to reduce code size for embedded targets which do 1012 not use transactional memory. 1013 </p> 1014 </dd> 1015 <dt><code class="code">--with-cpu=<var class="var">cpu</var></code></dt> 1016 <dt><code class="code">--with-cpu-32=<var class="var">cpu</var></code></dt> 1017 <dt><code class="code">--with-cpu-64=<var class="var">cpu</var></code></dt> 1018 <dd><p>Specify which cpu variant the compiler should generate code for by default. 1019 <var class="var">cpu</var> will be used as the default value of the <samp class="option">-mcpu=</samp> switch. 1020 This option is only supported on some targets, including ARC, ARM, i386, M68k, 1021 PowerPC, and SPARC. It is mandatory for ARC. The <samp class="option">--with-cpu-32</samp> and 1022 <samp class="option">--with-cpu-64</samp> options specify separate default CPUs for 1023 32-bit and 64-bit modes; these options are only supported for aarch64, i386, 1024 x86-64, PowerPC, and SPARC. 1025 </p> 1026 </dd> 1027 <dt><code class="code">--with-schedule=<var class="var">cpu</var></code></dt> 1028 <dt><code class="code">--with-arch=<var class="var">cpu</var></code></dt> 1029 <dt><code class="code">--with-arch-32=<var class="var">cpu</var></code></dt> 1030 <dt><code class="code">--with-arch-64=<var class="var">cpu</var></code></dt> 1031 <dt><code class="code">--with-tune=<var class="var">cpu</var></code></dt> 1032 <dt><code class="code">--with-tune-32=<var class="var">cpu</var></code></dt> 1033 <dt><code class="code">--with-tune-64=<var class="var">cpu</var></code></dt> 1034 <dt><code class="code">--with-abi=<var class="var">abi</var></code></dt> 1035 <dt><code class="code">--with-fpu=<var class="var">type</var></code></dt> 1036 <dt><code class="code">--with-float=<var class="var">type</var></code></dt> 1037 <dt><code class="code">--with-simd=<var class="var">type</var></code></dt> 1038 <dd><p>These configure options provide default values for the <samp class="option">-mschedule=</samp>, 1039 <samp class="option">-march=</samp>, <samp class="option">-mtune=</samp>, <samp class="option">-mabi=</samp>, and <samp class="option">-mfpu=</samp> 1040 options and for <samp class="option">-mhard-float</samp> or <samp class="option">-msoft-float</samp>. As with 1041 <samp class="option">--with-cpu</samp>, which switches will be accepted and acceptable values 1042 of the arguments depend on the target. 1043 </p> 1044 </dd> 1045 <dt><code class="code">--with-mode=<var class="var">mode</var></code></dt> 1046 <dd><p>Specify if the compiler should default to <samp class="option">-marm</samp> or <samp class="option">-mthumb</samp>. 1047 This option is only supported on ARM targets. 1048 </p> 1049 </dd> 1050 <dt><code class="code">--with-stack-offset=<var class="var">num</var></code></dt> 1051 <dd><p>This option sets the default for the -mstack-offset=<var class="var">num</var> option, 1052 and will thus generally also control the setting of this option for 1053 libraries. This option is only supported on Epiphany targets. 1054 </p> 1055 </dd> 1056 <dt><code class="code">--with-fpmath=<var class="var">isa</var></code></dt> 1057 <dd><p>This options sets <samp class="option">-mfpmath=sse</samp> by default and specifies the default 1058 ISA for floating-point arithmetics. You can select either ‘<samp class="samp">sse</samp>’ which 1059 enables <samp class="option">-msse2</samp> or ‘<samp class="samp">avx</samp>’ which enables <samp class="option">-mavx</samp> by default. 1060 This option is only supported on i386 and x86-64 targets. 1061 </p> 1062 </dd> 1063 <dt><code class="code">--with-fp-32=<var class="var">mode</var></code></dt> 1064 <dd><p>On MIPS targets, set the default value for the <samp class="option">-mfp</samp> option when using 1065 the o32 ABI. The possibilities for <var class="var">mode</var> are: 1066 </p><dl class="table"> 1067 <dt><code class="code">32</code></dt> 1068 <dd><p>Use the o32 FP32 ABI extension, as with the <samp class="option">-mfp32</samp> command-line 1069 option. 1070 </p></dd> 1071 <dt><code class="code">xx</code></dt> 1072 <dd><p>Use the o32 FPXX ABI extension, as with the <samp class="option">-mfpxx</samp> command-line 1073 option. 1074 </p></dd> 1075 <dt><code class="code">64</code></dt> 1076 <dd><p>Use the o32 FP64 ABI extension, as with the <samp class="option">-mfp64</samp> command-line 1077 option. 1078 </p></dd> 1079 </dl> 1080 <p>In the absence of this configuration option the default is to use the o32 1081 FP32 ABI extension. 1082 </p> 1083 </dd> 1084 <dt><code class="code">--with-odd-spreg-32</code></dt> 1085 <dd><p>On MIPS targets, set the <samp class="option">-modd-spreg</samp> option by default when using 1086 the o32 ABI. 1087 </p> 1088 </dd> 1089 <dt><code class="code">--without-odd-spreg-32</code></dt> 1090 <dd><p>On MIPS targets, set the <samp class="option">-mno-odd-spreg</samp> option by default when using 1091 the o32 ABI. This is normally used in conjunction with 1092 <samp class="option">--with-fp-32=64</samp> in order to target the o32 FP64A ABI extension. 1093 </p> 1094 </dd> 1095 <dt><code class="code">--with-nan=<var class="var">encoding</var></code></dt> 1096 <dd><p>On MIPS targets, set the default encoding convention to use for the 1097 special not-a-number (NaN) IEEE 754 floating-point data. The 1098 possibilities for <var class="var">encoding</var> are: 1099 </p><dl class="table"> 1100 <dt><code class="code">legacy</code></dt> 1101 <dd><p>Use the legacy encoding, as with the <samp class="option">-mnan=legacy</samp> command-line 1102 option. 1103 </p></dd> 1104 <dt><code class="code">2008</code></dt> 1105 <dd><p>Use the 754-2008 encoding, as with the <samp class="option">-mnan=2008</samp> command-line 1106 option. 1107 </p></dd> 1108 </dl> 1109 <p>To use this configuration option you must have an assembler version 1110 installed that supports the <samp class="option">-mnan=</samp> command-line option too. 1111 In the absence of this configuration option the default convention is 1112 the legacy encoding, as when neither of the <samp class="option">-mnan=2008</samp> and 1113 <samp class="option">-mnan=legacy</samp> command-line options has been used. 1114 </p> 1115 </dd> 1116 <dt><code class="code">--with-divide=<var class="var">type</var></code></dt> 1117 <dd><p>Specify how the compiler should generate code for checking for 1118 division by zero. This option is only supported on the MIPS target. 1119 The possibilities for <var class="var">type</var> are: 1120 </p><dl class="table"> 1121 <dt><code class="code">traps</code></dt> 1122 <dd><p>Division by zero checks use conditional traps (this is the default on 1123 systems that support conditional traps). 1124 </p></dd> 1125 <dt><code class="code">breaks</code></dt> 1126 <dd><p>Division by zero checks use the break instruction. 1127 </p></dd> 1128 </dl> 1129 1130 </dd> 1131 <dt><code class="code">--with-compact-branches=<var class="var">policy</var></code></dt> 1132 <dd><p>Specify how the compiler should generate branch instructions. 1133 This option is only supported on the MIPS target. 1134 The possibilities for <var class="var">type</var> are: 1135 </p><dl class="table"> 1136 <dt><code class="code">optimal</code></dt> 1137 <dd><p>Cause a delay slot branch to be used if one is available in the 1138 current ISA and the delay slot is successfully filled. If the delay slot 1139 is not filled, a compact branch will be chosen if one is available. 1140 </p></dd> 1141 <dt><code class="code">never</code></dt> 1142 <dd><p>Ensures that compact branch instructions will never be generated. 1143 </p></dd> 1144 <dt><code class="code">always</code></dt> 1145 <dd><p>Ensures that a compact branch instruction will be generated if available. 1146 If a compact branch instruction is not available, 1147 a delay slot form of the branch will be used instead. 1148 This option is supported from MIPS Release 6 onwards. 1149 For pre-R6/microMIPS/MIPS16, this option is just same as never/optimal. 1150 </p></dd> 1151 </dl> 1152 1153 1154 </dd> 1155 <dt><code class="code">--with-llsc</code></dt> 1156 <dd><p>On MIPS targets, make <samp class="option">-mllsc</samp> the default when no 1157 <samp class="option">-mno-llsc</samp> option is passed. This is the default for 1158 Linux-based targets, as the kernel will emulate them if the ISA does 1159 not provide them. 1160 </p> 1161 </dd> 1162 <dt><code class="code">--without-llsc</code></dt> 1163 <dd><p>On MIPS targets, make <samp class="option">-mno-llsc</samp> the default when no 1164 <samp class="option">-mllsc</samp> option is passed. 1165 </p> 1166 </dd> 1167 <dt><code class="code">--with-synci</code></dt> 1168 <dd><p>On MIPS targets, make <samp class="option">-msynci</samp> the default when no 1169 <samp class="option">-mno-synci</samp> option is passed. 1170 </p> 1171 </dd> 1172 <dt><code class="code">--without-synci</code></dt> 1173 <dd><p>On MIPS targets, make <samp class="option">-mno-synci</samp> the default when no 1174 <samp class="option">-msynci</samp> option is passed. This is the default. 1175 </p> 1176 </dd> 1177 <dt><code class="code">--with-lxc1-sxc1</code></dt> 1178 <dd><p>On MIPS targets, make <samp class="option">-mlxc1-sxc1</samp> the default when no 1179 <samp class="option">-mno-lxc1-sxc1</samp> option is passed. This is the default. 1180 </p> 1181 </dd> 1182 <dt><code class="code">--without-lxc1-sxc1</code></dt> 1183 <dd><p>On MIPS targets, make <samp class="option">-mno-lxc1-sxc1</samp> the default when no 1184 <samp class="option">-mlxc1-sxc1</samp> option is passed. The indexed load/store 1185 instructions are not directly a problem but can lead to unexpected 1186 behaviour when deployed in an application intended for a 32-bit address 1187 space but run on a 64-bit processor. The issue is seen because all 1188 known MIPS 64-bit Linux kernels execute o32 and n32 applications 1189 with 64-bit addressing enabled which affects the overflow behaviour 1190 of the indexed addressing mode. GCC will assume that ordinary 1191 32-bit arithmetic overflow behaviour is the same whether performed 1192 as an <code class="code">addu</code> instruction or as part of the address calculation 1193 in <code class="code">lwxc1</code> type instructions. This assumption holds true in a 1194 pure 32-bit environment and can hold true in a 64-bit environment if 1195 the address space is accurately set to be 32-bit for o32 and n32. 1196 </p> 1197 </dd> 1198 <dt><code class="code">--with-madd4</code></dt> 1199 <dd><p>On MIPS targets, make <samp class="option">-mmadd4</samp> the default when no 1200 <samp class="option">-mno-madd4</samp> option is passed. This is the default. 1201 </p> 1202 </dd> 1203 <dt><code class="code">--without-madd4</code></dt> 1204 <dd><p>On MIPS targets, make <samp class="option">-mno-madd4</samp> the default when no 1205 <samp class="option">-mmadd4</samp> option is passed. The <code class="code">madd4</code> instruction 1206 family can be problematic when targeting a combination of cores that 1207 implement these instructions differently. There are two known cores 1208 that implement these as fused operations instead of unfused (where 1209 unfused is normally expected). Disabling these instructions is the 1210 only way to ensure compatible code is generated; this will incur 1211 a performance penalty. 1212 </p> 1213 </dd> 1214 <dt><code class="code">--with-msa</code></dt> 1215 <dd><p>On MIPS targets, make <samp class="option">-mmsa</samp> the default when no 1216 <samp class="option">-mno-msa</samp> option is passed. 1217 </p> 1218 </dd> 1219 <dt><code class="code">--without-msa</code></dt> 1220 <dd><p>On MIPS targets, make <samp class="option">-mno-msa</samp> the default when no 1221 <samp class="option">-mmsa</samp> option is passed. This is the default. 1222 </p> 1223 </dd> 1224 <dt><code class="code">--with-mips-plt</code></dt> 1225 <dd><p>On MIPS targets, make use of copy relocations and PLTs. 1226 These features are extensions to the traditional 1227 SVR4-based MIPS ABIs and require support from GNU binutils 1228 and the runtime C library. 1229 </p> 1230 </dd> 1231 <dt><code class="code">--with-stack-clash-protection-guard-size=<var class="var">size</var></code></dt> 1232 <dd><p>On certain targets this option sets the default stack clash protection guard 1233 size as a power of two in bytes. On AArch64 <var class="var">size</var> is required to be either 1234 12 (4KB) or 16 (64KB). 1235 </p> 1236 </dd> 1237 <dt><code class="code">--with-isa-spec=<var class="var">ISA-spec-string</var></code></dt> 1238 <dd><p>On RISC-V targets specify the default version of the RISC-V Unprivileged 1239 (formerly User-Level) ISA specification to produce code conforming to. 1240 The possibilities for <var class="var">ISA-spec-string</var> are: 1241 </p><dl class="table"> 1242 <dt><code class="code">2.2</code></dt> 1243 <dd><p>Produce code conforming to version 2.2. 1244 </p></dd> 1245 <dt><code class="code">20190608</code></dt> 1246 <dd><p>Produce code conforming to version 20190608. 1247 </p></dd> 1248 <dt><code class="code">20191213</code></dt> 1249 <dd><p>Produce code conforming to version 20191213. 1250 </p></dd> 1251 </dl> 1252 <p>In the absence of this configuration option the default version is 20191213. 1253 </p> 1254 </dd> 1255 <dt><code class="code">--enable-__cxa_atexit</code></dt> 1256 <dd><p>Define if you want to use __cxa_atexit, rather than atexit, to 1257 register C++ destructors for local statics and global objects. 1258 This is essential for fully standards-compliant handling of 1259 destructors, but requires __cxa_atexit in libc. This option is currently 1260 only available on systems with GNU libc. When enabled, this will cause 1261 <samp class="option">-fuse-cxa-atexit</samp> to be passed by default. 1262 </p> 1263 </dd> 1264 <dt><code class="code">--enable-gnu-indirect-function</code></dt> 1265 <dd><p>Define if you want to enable the <code class="code">ifunc</code> attribute. This option is 1266 currently only available on systems with GNU libc on certain targets. 1267 </p> 1268 </dd> 1269 <dt><code class="code">--enable-target-optspace</code></dt> 1270 <dd><p>Specify that target 1271 libraries should be optimized for code space instead of code speed. 1272 This is the default for the m32r platform. 1273 </p> 1274 </dd> 1275 <dt><code class="code">--with-cpp-install-dir=<var class="var">dirname</var></code></dt> 1276 <dd><p>Specify that the user visible <code class="command">cpp</code> program should be installed 1277 in <samp class="file"><var class="var">prefix</var>/<var class="var">dirname</var>/cpp</samp>, in addition to <var class="var">bindir</var>. 1278 </p> 1279 </dd> 1280 <dt><code class="code">--enable-comdat</code></dt> 1281 <dd><p>Enable COMDAT group support. This is primarily used to override the 1282 automatically detected value. 1283 </p> 1284 </dd> 1285 <dt><code class="code">--enable-initfini-array</code></dt> 1286 <dd><p>Force the use of sections <code class="code">.init_array</code> and <code class="code">.fini_array</code> 1287 (instead of <code class="code">.init</code> and <code class="code">.fini</code>) for constructors and 1288 destructors. Option <samp class="option">--disable-initfini-array</samp> has the 1289 opposite effect. If neither option is specified, the configure script 1290 will try to guess whether the <code class="code">.init_array</code> and 1291 <code class="code">.fini_array</code> sections are supported and, if they are, use them. 1292 </p> 1293 </dd> 1294 <dt><code class="code">--enable-link-mutex</code></dt> 1295 <dd><p>When building GCC, use a mutex to avoid linking the compilers for 1296 multiple languages at the same time, to avoid thrashing on build 1297 systems with limited free memory. The default is not to use such a mutex. 1298 </p> 1299 </dd> 1300 <dt><code class="code">--enable-link-serialization</code></dt> 1301 <dd><p>When building GCC, use make dependencies to serialize linking the compilers for 1302 multiple languages, to avoid thrashing on build 1303 systems with limited free memory. The default is not to add such 1304 dependencies and thus with parallel make potentially link different 1305 compilers concurrently. If the argument is a positive integer, allow 1306 that number of concurrent link processes for the large binaries. 1307 </p> 1308 </dd> 1309 <dt><code class="code">--enable-maintainer-mode</code></dt> 1310 <dd><p>The build rules that regenerate the Autoconf and Automake output files as 1311 well as the GCC master message catalog <samp class="file">gcc.pot</samp> are normally 1312 disabled. This is because it can only be rebuilt if the complete source 1313 tree is present. If you have changed the sources and want to rebuild the 1314 catalog, configuring with <samp class="option">--enable-maintainer-mode</samp> will enable 1315 this. Note that you need a recent version of the <code class="code">gettext</code> tools 1316 to do so. 1317 </p> 1318 </dd> 1319 <dt><code class="code">--disable-bootstrap</code></dt> 1320 <dd><p>For a native build, the default configuration is to perform 1321 a 3-stage bootstrap of the compiler when ‘<samp class="samp">make</samp>’ is invoked, 1322 testing that GCC can compile itself correctly. If you want to disable 1323 this process, you can configure with <samp class="option">--disable-bootstrap</samp>. 1324 </p> 1325 </dd> 1326 <dt><code class="code">--enable-bootstrap</code></dt> 1327 <dd><p>In special cases, you may want to perform a 3-stage build 1328 even if the target and host triplets are different. 1329 This is possible when the host can run code compiled for 1330 the target (e.g. host is i686-linux, target is i486-linux). 1331 Starting from GCC 4.2, to do this you have to configure explicitly 1332 with <samp class="option">--enable-bootstrap</samp>. 1333 </p> 1334 </dd> 1335 <dt><code class="code">--enable-generated-files-in-srcdir</code></dt> 1336 <dd><p>Neither the .c and .h files that are generated from Bison and flex nor the 1337 info manuals and man pages that are built from the .texi files are present 1338 in the repository development tree. When building GCC from that development tree, 1339 or from one of our snapshots, those generated files are placed in your 1340 build directory, which allows for the source to be in a readonly 1341 directory. 1342 </p> 1343 <p>If you configure with <samp class="option">--enable-generated-files-in-srcdir</samp> then those 1344 generated files will go into the source directory. This is mainly intended 1345 for generating release or prerelease tarballs of the GCC sources, since it 1346 is not a requirement that the users of source releases to have flex, Bison, 1347 or makeinfo. 1348 </p> 1349 </dd> 1350 <dt><code class="code">--enable-version-specific-runtime-libs</code></dt> 1351 <dd><p>Specify 1352 that runtime libraries should be installed in the compiler specific 1353 subdirectory (<samp class="file"><var class="var">libdir</var>/gcc</samp>) rather than the usual places. In 1354 addition, ‘<samp class="samp">libstdc++</samp>’’s include files will be installed into 1355 <samp class="file"><var class="var">libdir</var></samp> unless you overruled it by using 1356 <samp class="option">--with-gxx-include-dir=<var class="var">dirname</var></samp>. Using this option is 1357 particularly useful if you intend to use several versions of GCC in 1358 parallel. The default is ‘<samp class="samp">yes</samp>’ for ‘<samp class="samp">libada</samp>’, and ‘<samp class="samp">no</samp>’ for 1359 the remaining libraries. 1360 </p> 1361 </dd> 1362 <dt><code class="code">--with-darwin-extra-rpath</code></dt> 1363 <dd><p>This is provided to allow distributions to add a single additional 1364 runpath on Darwin / macOS systems. This allows for cases where the 1365 installed GCC library directories are then symlinked to a common 1366 directory outside of the GCC installation. 1367 </p> 1368 </dd> 1369 <dt><code class="code"><a class="anchor" id="WithAixSoname"></a>--with-aix-soname=‘<samp class="samp">aix</samp>’, ‘<samp class="samp">svr4</samp>’ or ‘<samp class="samp">both</samp>’</code></dt> 1370 <dd><p>Traditional AIX shared library versioning (versioned <code class="code">Shared Object</code> 1371 files as members of unversioned <code class="code">Archive Library</code> files named 1372 ‘<samp class="samp">lib.a</samp>’) causes numerous headaches for package managers. However, 1373 <code class="code">Import Files</code> as members of <code class="code">Archive Library</code> files allow for 1374 <strong class="strong">filename-based versioning</strong> of shared libraries as seen on Linux/SVR4, 1375 where this is called the "SONAME". But as they prevent static linking, 1376 <code class="code">Import Files</code> may be used with <code class="code">Runtime Linking</code> only, where the 1377 linker does search for ‘<samp class="samp">libNAME.so</samp>’ before ‘<samp class="samp">libNAME.a</samp>’ library 1378 filenames with the ‘<samp class="samp">-lNAME</samp>’ linker flag. 1379 </p> 1380 <a class="anchor" id="AixLdCommand"></a><p>For detailed information please refer to the AIX 1381 <a class="uref" href="https://www.ibm.com/support/knowledgecenter/search/%22the%20ld%20command%2C%20also%20called%20the%20linkage%20editor%20or%20binder%22">ld 1382 Command</a> reference. 1383 </p> 1384 <p>As long as shared library creation is enabled, upon: 1385 </p><dl class="table"> 1386 <dt><code class="code">--with-aix-soname=aix</code></dt> 1387 <dt><code class="code">--with-aix-soname=both</code></dt> 1388 <dd><p>A (traditional AIX) <code class="code">Shared Archive Library</code> file is created: 1389 </p><ul class="itemize mark-bullet"> 1390 <li>using the ‘<samp class="samp">libNAME.a</samp>’ filename scheme 1391 </li><li>with the <code class="code">Shared Object</code> file as archive member named 1392 ‘<samp class="samp">libNAME.so.V</samp>’ (except for ‘<samp class="samp">libgcc_s</samp>’, where the <code class="code">Shared 1393 Object</code> file is named ‘<samp class="samp">shr.o</samp>’ for backwards compatibility), which 1394 <ul class="itemize mark-minus"> 1395 <li>is used for runtime loading from inside the ‘<samp class="samp">libNAME.a</samp>’ file 1396 </li><li>is used for dynamic loading via 1397 <code class="code">dlopen("libNAME.a(libNAME.so.V)", RTLD_MEMBER)</code> 1398 </li><li>is used for shared linking 1399 </li><li>is used for static linking, so no separate <code class="code">Static Archive 1400 Library</code> file is needed 1401 </li></ul> 1402 </li></ul> 1403 </dd> 1404 <dt><code class="code">--with-aix-soname=both</code></dt> 1405 <dt><code class="code">--with-aix-soname=svr4</code></dt> 1406 <dd><p>A (second) <code class="code">Shared Archive Library</code> file is created: 1407 </p><ul class="itemize mark-bullet"> 1408 <li>using the ‘<samp class="samp">libNAME.so.V</samp>’ filename scheme 1409 </li><li>with the <code class="code">Shared Object</code> file as archive member named 1410 ‘<samp class="samp">shr.o</samp>’, which 1411 <ul class="itemize mark-minus"> 1412 <li>is created with the <code class="code">-G linker flag</code> 1413 </li><li>has the <code class="code">F_LOADONLY</code> flag set 1414 </li><li>is used for runtime loading from inside the ‘<samp class="samp">libNAME.so.V</samp>’ file 1415 </li><li>is used for dynamic loading via <code class="code">dlopen("libNAME.so.V(shr.o)", 1416 RTLD_MEMBER)</code> 1417 </li></ul> 1418 </li><li>with the <code class="code">Import File</code> as archive member named ‘<samp class="samp">shr.imp</samp>’, 1419 which 1420 <ul class="itemize mark-minus"> 1421 <li>refers to ‘<samp class="samp">libNAME.so.V(shr.o)</samp>’ as the "SONAME", to be recorded 1422 in the <code class="code">Loader Section</code> of subsequent binaries 1423 </li><li>indicates whether ‘<samp class="samp">libNAME.so.V(shr.o)</samp>’ is 32 or 64 bit 1424 </li><li>lists all the public symbols exported by ‘<samp class="samp">lib.so.V(shr.o)</samp>’, 1425 eventually decorated with the <code class="code">‘<samp class="samp">weak</samp>’ Keyword</code> 1426 </li><li>is necessary for shared linking against ‘<samp class="samp">lib.so.V(shr.o)</samp>’ 1427 </li></ul> 1428 </li></ul> 1429 <p>A symbolic link using the ‘<samp class="samp">libNAME.so</samp>’ filename scheme is created: 1430 </p><ul class="itemize mark-bullet"> 1431 <li>pointing to the ‘<samp class="samp">libNAME.so.V</samp>’ <code class="code">Shared Archive Library</code> file 1432 </li><li>to permit the <code class="code">ld Command</code> to find ‘<samp class="samp">lib.so.V(shr.imp)</samp>’ via 1433 the ‘<samp class="samp">-lNAME</samp>’ argument (requires <code class="code">Runtime Linking</code> to be enabled) 1434 </li><li>to permit dynamic loading of ‘<samp class="samp">lib.so.V(shr.o)</samp>’ without the need 1435 to specify the version number via <code class="code">dlopen("libNAME.so(shr.o)", 1436 RTLD_MEMBER)</code> 1437 </li></ul> 1438 </dd> 1439 </dl> 1440 1441 <p>As long as static library creation is enabled, upon: 1442 </p><dl class="table"> 1443 <dt><code class="code">--with-aix-soname=svr4</code></dt> 1444 <dd><p>A <code class="code">Static Archive Library</code> is created: 1445 </p><ul class="itemize mark-bullet"> 1446 <li>using the ‘<samp class="samp">libNAME.a</samp>’ filename scheme 1447 </li><li>with all the <code class="code">Static Object</code> files as archive members, which 1448 <ul class="itemize mark-minus"> 1449 <li>are used for static linking 1450 </li></ul> 1451 </li></ul> 1452 </dd> 1453 </dl> 1454 1455 <p>While the aix-soname=‘<samp class="samp">svr4</samp>’ option does not create <code class="code">Shared Object</code> 1456 files as members of unversioned <code class="code">Archive Library</code> files any more, package 1457 managers still are responsible to 1458 <a class="uref" href="./specific.html#TransferAixShobj">transfer</a> <code class="code">Shared Object</code> files 1459 found as member of a previously installed unversioned <code class="code">Archive Library</code> 1460 file into the newly installed <code class="code">Archive Library</code> file with the same 1461 filename. 1462 </p> 1463 <p><em class="emph">WARNING:</em> Creating <code class="code">Shared Object</code> files with <code class="code">Runtime Linking</code> 1464 enabled may bloat the TOC, eventually leading to <code class="code">TOC overflow</code> errors, 1465 requiring the use of either the <samp class="option">-Wl,-bbigtoc</samp> linker flag (seen to 1466 break with the <code class="code">GDB</code> debugger) or some of the TOC-related compiler flags, 1467 see “RS/6000 and PowerPC Options” in the main manual. 1468 </p> 1469 <p><samp class="option">--with-aix-soname</samp> is currently supported by ‘<samp class="samp">libgcc_s</samp>’ only, so 1470 this option is still experimental and not for normal use yet. 1471 </p> 1472 <p>Default is the traditional behavior <samp class="option">--with-aix-soname=‘<samp class="samp">aix</samp>’</samp>. 1473 </p> 1474 </dd> 1475 <dt><code class="code">--enable-languages=<var class="var">lang1</var>,<var class="var">lang2</var>,…</code></dt> 1476 <dd><p>Specify that only a particular subset of compilers and 1477 their runtime libraries should be built. For a list of valid values for 1478 <var class="var">langN</var> you can issue the following command in the 1479 <samp class="file">gcc</samp> directory of your GCC source tree:<br> 1480 </p><div class="example smallexample"> 1481 <pre class="example-preformatted">grep ^language= */config-lang.in 1482 </pre></div> 1483 <p>Currently, you can use any of the following: 1484 <code class="code">all</code>, <code class="code">default</code>, <code class="code">ada</code>, <code class="code">c</code>, <code class="code">c++</code>, <code class="code">d</code>, 1485 <code class="code">fortran</code>, <code class="code">go</code>, <code class="code">jit</code>, <code class="code">lto</code>, <code class="code">m2</code>, 1486 <code class="code">objc</code>, <code class="code">obj-c++</code>. 1487 Building the Ada compiler has special requirements, see below. 1488 If you do not pass this flag, or specify the option <code class="code">default</code>, then the 1489 default languages available in the <samp class="file">gcc</samp> sub-tree will be configured. 1490 Ada, D, Go, Jit, Objective-C++ and Modula-2 are not default languages. 1491 LTO is not a 1492 default language, but is built by default because <samp class="option">--enable-lto</samp> is 1493 enabled by default. The other languages are default languages. If 1494 <code class="code">all</code> is specified, then all available languages are built. An 1495 exception is <code class="code">jit</code> language, which requires 1496 <samp class="option">--enable-host-shared</samp> to be included with <code class="code">all</code>. 1497 </p> 1498 </dd> 1499 <dt><code class="code">--enable-stage1-languages=<var class="var">lang1</var>,<var class="var">lang2</var>,…</code></dt> 1500 <dd><p>Specify that a particular subset of compilers and their runtime 1501 libraries should be built with the system C compiler during stage 1 of 1502 the bootstrap process, rather than only in later stages with the 1503 bootstrapped C compiler. The list of valid values is the same as for 1504 <samp class="option">--enable-languages</samp>, and the option <code class="code">all</code> will select all 1505 of the languages enabled by <samp class="option">--enable-languages</samp>. This option is 1506 primarily useful for GCC development; for instance, when a development 1507 version of the compiler cannot bootstrap due to compiler bugs, or when 1508 one is debugging front ends other than the C front end. When this 1509 option is used, one can then build the target libraries for the 1510 specified languages with the stage-1 compiler by using <code class="command">make 1511 stage1-bubble all-target</code>, or run the testsuite on the stage-1 compiler 1512 for the specified languages using <code class="command">make stage1-start check-gcc</code>. 1513 </p> 1514 </dd> 1515 <dt><code class="code">--disable-libada</code></dt> 1516 <dd><p>Specify that the run-time libraries and tools used by GNAT should not 1517 be built. This can be useful for debugging, or for compatibility with 1518 previous Ada build procedures, when it was required to explicitly 1519 do a ‘<samp class="samp">make -C gcc gnatlib_and_tools</samp>’. 1520 </p> 1521 </dd> 1522 <dt><code class="code">--disable-libgm2</code></dt> 1523 <dd><p>Specify that the run-time libraries and tools used by Modula-2 should not 1524 be built. This can be useful for debugging. 1525 </p> 1526 </dd> 1527 <dt><code class="code">--disable-libsanitizer</code></dt> 1528 <dd><p>Specify that the run-time libraries for the various sanitizers should 1529 not be built. 1530 </p> 1531 </dd> 1532 <dt><code class="code">--disable-libssp</code></dt> 1533 <dd><p>Specify that the run-time libraries for stack smashing protection 1534 should not be built or linked against. On many targets library support 1535 is provided by the C library instead. 1536 </p> 1537 </dd> 1538 <dt><code class="code">--disable-libquadmath</code></dt> 1539 <dd><p>Specify that the GCC quad-precision math library should not be built. 1540 On some systems, the library is required to be linkable when building 1541 the Fortran front end, unless <samp class="option">--disable-libquadmath-support</samp> 1542 is used. 1543 </p> 1544 </dd> 1545 <dt><code class="code">--disable-libquadmath-support</code></dt> 1546 <dd><p>Specify that the Fortran front end and <code class="code">libgfortran</code> do not add 1547 support for <code class="code">libquadmath</code> on systems supporting it. 1548 </p> 1549 </dd> 1550 <dt><code class="code">--disable-libgomp</code></dt> 1551 <dd><p>Specify that the GNU Offloading and Multi Processing Runtime Library 1552 should not be built. 1553 </p> 1554 </dd> 1555 <dt><code class="code">--disable-libvtv</code></dt> 1556 <dd><p>Specify that the run-time libraries used by vtable verification 1557 should not be built. 1558 </p> 1559 </dd> 1560 <dt><code class="code">--with-dwarf2</code></dt> 1561 <dd><p>Specify that the compiler should 1562 use DWARF debugging information as the default; the exact 1563 DWARF version that is the default is target-specific. 1564 </p> 1565 </dd> 1566 <dt><code class="code">--with-advance-toolchain=<var class="var">at</var></code></dt> 1567 <dd><p>On 64-bit PowerPC Linux systems, configure the compiler to use the 1568 header files, library files, and the dynamic linker from the Advance 1569 Toolchain release <var class="var">at</var> instead of the default versions that are 1570 provided by the Linux distribution. In general, this option is 1571 intended for the developers of GCC, and it is not intended for general 1572 use. 1573 </p> 1574 </dd> 1575 <dt><code class="code">--enable-targets=all</code></dt> 1576 <dt><code class="code">--enable-targets=<var class="var">target_list</var></code></dt> 1577 <dd><p>Some GCC targets, e.g. powerpc64-linux, build bi-arch compilers. 1578 These are compilers that are able to generate either 64-bit or 32-bit 1579 code. Typically, the corresponding 32-bit target, e.g. 1580 powerpc-linux for powerpc64-linux, only generates 32-bit code. This 1581 option enables the 32-bit target to be a bi-arch compiler, which is 1582 useful when you want a bi-arch compiler that defaults to 32-bit, and 1583 you are building a bi-arch or multi-arch binutils in a combined tree. 1584 On mips-linux, this will build a tri-arch compiler (ABI o32/n32/64), 1585 defaulted to o32. 1586 Currently, this option only affects sparc-linux, powerpc-linux, x86-linux, 1587 mips-linux and s390-linux. 1588 </p> 1589 </dd> 1590 <dt><code class="code">--enable-default-pie</code></dt> 1591 <dd><p>Turn on <samp class="option">-fPIE</samp> and <samp class="option">-pie</samp> by default. 1592 </p> 1593 </dd> 1594 <dt><code class="code">--enable-secureplt</code></dt> 1595 <dd><p>This option enables <samp class="option">-msecure-plt</samp> by default for powerpc-linux. 1596 See “RS/6000 and PowerPC Options” in the main manual 1597 </p> 1598 </dd> 1599 <dt><code class="code">--enable-default-ssp</code></dt> 1600 <dd><p>Turn on <samp class="option">-fstack-protector-strong</samp> by default. 1601 </p> 1602 </dd> 1603 <dt><code class="code">--enable-cld</code></dt> 1604 <dd><p>This option enables <samp class="option">-mcld</samp> by default for 32-bit x86 targets. 1605 See “i386 and x86-64 Options” in the main manual 1606 </p> 1607 </dd> 1608 <dt><code class="code">--enable-large-address-aware</code></dt> 1609 <dd><p>The <samp class="option">--enable-large-address-aware</samp> option arranges for MinGW 1610 executables to be linked using the <samp class="option">--large-address-aware</samp> 1611 option, that enables the use of more than 2GB of memory. If GCC is 1612 configured with this option, its effects can be reversed by passing the 1613 <samp class="option">-Wl,--disable-large-address-aware</samp> option to the so-configured 1614 compiler driver. 1615 </p> 1616 </dd> 1617 <dt><code class="code">--enable-win32-registry</code></dt> 1618 <dt><code class="code">--enable-win32-registry=<var class="var">key</var></code></dt> 1619 <dt><code class="code">--disable-win32-registry</code></dt> 1620 <dd><p>The <samp class="option">--enable-win32-registry</samp> option enables Microsoft Windows-hosted GCC 1621 to look up installations paths in the registry using the following key: 1622 </p> 1623 <div class="example smallexample"> 1624 <pre class="example-preformatted"><code class="code">HKEY_LOCAL_MACHINE\SOFTWARE\Free Software Foundation\<var class="var">key</var></code> 1625 </pre></div> 1626 1627 <p><var class="var">key</var> defaults to GCC version number, and can be overridden by the 1628 <samp class="option">--enable-win32-registry=<var class="var">key</var></samp> option. Vendors and distributors 1629 who use custom installers are encouraged to provide a different key, 1630 perhaps one comprised of vendor name and GCC version number, to 1631 avoid conflict with existing installations. This feature is enabled 1632 by default, and can be disabled by <samp class="option">--disable-win32-registry</samp> 1633 option. This option has no effect on the other hosts. 1634 </p> 1635 </dd> 1636 <dt><code class="code">--nfp</code></dt> 1637 <dd><p>Specify that the machine does not have a floating point unit. This 1638 option only applies to ‘<samp class="samp">m68k-sun-sunos<var class="var">n</var></samp>’. On any other 1639 system, <samp class="option">--nfp</samp> has no effect. 1640 </p> 1641 </dd> 1642 <dt><code class="code">--enable-werror</code></dt> 1643 <dt><code class="code">--disable-werror</code></dt> 1644 <dt><code class="code">--enable-werror=yes</code></dt> 1645 <dt><code class="code">--enable-werror=no</code></dt> 1646 <dd><p>When you specify this option, it controls whether certain files in the 1647 compiler are built with <samp class="option">-Werror</samp> in bootstrap stage2 and later. 1648 If you don’t specify it, <samp class="option">-Werror</samp> is turned on for the main 1649 development trunk. However it defaults to off for release branches and 1650 final releases. The specific files which get <samp class="option">-Werror</samp> are 1651 controlled by the Makefiles. 1652 </p> 1653 </dd> 1654 <dt><code class="code">--enable-checking</code></dt> 1655 <dt><code class="code">--disable-checking</code></dt> 1656 <dt><code class="code">--enable-checking=<var class="var">list</var></code></dt> 1657 <dd><p>This option controls performing internal consistency checks in the compiler. 1658 It does not change the generated code, but adds error checking of the 1659 requested complexity. This slows down the compiler and may only work 1660 properly if you are building the compiler with GCC. 1661 </p> 1662 <p>When the option is not specified, the active set of checks depends on context. 1663 Namely, bootstrap stage 1 defaults to ‘<samp class="samp">--enable-checking=yes</samp>’, builds 1664 from release branches or release archives default to 1665 ‘<samp class="samp">--enable-checking=release</samp>’, and otherwise 1666 ‘<samp class="samp">--enable-checking=yes,extra</samp>’ is used. When the option is 1667 specified without a <var class="var">list</var>, the result is the same as 1668 ‘<samp class="samp">--enable-checking=yes</samp>’. Likewise, ‘<samp class="samp">--disable-checking</samp>’ is 1669 equivalent to ‘<samp class="samp">--enable-checking=no</samp>’. 1670 </p> 1671 <p>The categories of checks available in <var class="var">list</var> are ‘<samp class="samp">yes</samp>’ (most common 1672 checks ‘<samp class="samp">assert,misc,gc,gimple,rtlflag,runtime,tree,types</samp>’), ‘<samp class="samp">no</samp>’ 1673 (no checks at all), ‘<samp class="samp">all</samp>’ (all but ‘<samp class="samp">valgrind</samp>’), ‘<samp class="samp">release</samp>’ 1674 (cheapest checks ‘<samp class="samp">assert,runtime</samp>’) or ‘<samp class="samp">none</samp>’ (same as ‘<samp class="samp">no</samp>’). 1675 ‘<samp class="samp">release</samp>’ checks are always on and to disable them 1676 ‘<samp class="samp">--disable-checking</samp>’ or ‘<samp class="samp">--enable-checking=no[,<other checks>]</samp>’ 1677 must be explicitly requested. Disabling assertions makes the compiler and 1678 runtime slightly faster but increases the risk of undetected internal errors 1679 causing wrong code to be generated. 1680 </p> 1681 <p>Individual checks can be enabled with these flags: ‘<samp class="samp">assert</samp>’, ‘<samp class="samp">df</samp>’, 1682 ‘<samp class="samp">extra</samp>’, ‘<samp class="samp">fold</samp>’, ‘<samp class="samp">gc</samp>’, ‘<samp class="samp">gcac</samp>’, ‘<samp class="samp">gimple</samp>’, 1683 ‘<samp class="samp">misc</samp>’, ‘<samp class="samp">rtl</samp>’, ‘<samp class="samp">rtlflag</samp>’, ‘<samp class="samp">runtime</samp>’, ‘<samp class="samp">tree</samp>’, 1684 ‘<samp class="samp">types</samp>’ and ‘<samp class="samp">valgrind</samp>’. ‘<samp class="samp">extra</samp>’ extends ‘<samp class="samp">misc</samp>’ 1685 checking with extra checks that might affect code generation and should 1686 therefore not differ between stage1 and later stages in bootstrap. 1687 </p> 1688 <p>The ‘<samp class="samp">valgrind</samp>’ check requires the external <code class="command">valgrind</code> simulator, 1689 available from <a class="uref" href="https://valgrind.org">https://valgrind.org</a>. The ‘<samp class="samp">rtl</samp>’ checks are 1690 expensive and the ‘<samp class="samp">df</samp>’, ‘<samp class="samp">gcac</samp>’ and ‘<samp class="samp">valgrind</samp>’ checks are very 1691 expensive. 1692 </p> 1693 </dd> 1694 <dt><code class="code">--disable-stage1-checking</code></dt> 1695 <dt><code class="code">--enable-stage1-checking</code></dt> 1696 <dt><code class="code">--enable-stage1-checking=<var class="var">list</var></code></dt> 1697 <dd><p>This option affects only bootstrap build. If no <samp class="option">--enable-checking</samp> 1698 option is specified the stage1 compiler is built with ‘<samp class="samp">yes</samp>’ checking 1699 enabled, otherwise the stage1 checking flags are the same as specified by 1700 <samp class="option">--enable-checking</samp>. To build the stage1 compiler with 1701 different checking options use <samp class="option">--enable-stage1-checking</samp>. 1702 The list of checking options is the same as for <samp class="option">--enable-checking</samp>. 1703 If your system is too slow or too small to bootstrap a released compiler 1704 with checking for stage1 enabled, you can use ‘<samp class="samp">--disable-stage1-checking</samp>’ 1705 to disable checking for the stage1 compiler. 1706 </p> 1707 </dd> 1708 <dt><code class="code">--enable-coverage</code></dt> 1709 <dt><code class="code">--enable-coverage=<var class="var">level</var></code></dt> 1710 <dd><p>With this option, the compiler is built to collect self coverage 1711 information, every time it is run. This is for internal development 1712 purposes, and only works when the compiler is being built with gcc. The 1713 <var class="var">level</var> argument controls whether the compiler is built optimized or 1714 not, values are ‘<samp class="samp">opt</samp>’ and ‘<samp class="samp">noopt</samp>’. For coverage analysis you 1715 want to disable optimization, for performance analysis you want to 1716 enable optimization. When coverage is enabled, the default level is 1717 without optimization. 1718 </p> 1719 </dd> 1720 <dt><code class="code">--enable-gather-detailed-mem-stats</code></dt> 1721 <dd><p>When this option is specified more detailed information on memory 1722 allocation is gathered. This information is printed when using 1723 <samp class="option">-fmem-report</samp>. 1724 </p> 1725 </dd> 1726 <dt><code class="code">--enable-valgrind-annotations</code></dt> 1727 <dd><p>Mark selected memory related operations in the compiler when run under 1728 valgrind to suppress false positives. 1729 </p> 1730 </dd> 1731 <dt><code class="code">--enable-nls</code></dt> 1732 <dt><code class="code">--disable-nls</code></dt> 1733 <dd><p>The <samp class="option">--enable-nls</samp> option enables Native Language Support (NLS), 1734 which lets GCC output diagnostics in languages other than American 1735 English. Native Language Support is enabled by default if not doing a 1736 canadian cross build. The <samp class="option">--disable-nls</samp> option disables NLS. 1737 </p> 1738 <p>Note that this functionality requires either libintl (provided by GNU 1739 gettext) or C standard library that contains support for gettext (such 1740 as the GNU C Library). 1741 See <a class="xref" href="#with-included-gettext">–with-included-gettext</a> for more 1742 information on the conditions required to get gettext support. 1743 </p> 1744 </dd> 1745 <dt><code class="code">--with-libintl-prefix=<var class="var">dir</var></code></dt> 1746 <dt><code class="code">--without-libintl-prefix</code></dt> 1747 <dd><p>Searches for libintl in <samp class="file"><var class="var">dir</var>/include</samp> and 1748 <samp class="file"><var class="var">dir</var>/lib</samp>, or disables manual searching for it, letting the 1749 linker handle it. 1750 </p> 1751 </dd> 1752 <dt><code class="code">--with-libintl-type=<var class="var">type</var></code></dt> 1753 <dd><p>Specifies the type of library to search for when looking for libintl. 1754 <var class="var">type</var> can be one of <code class="code">auto</code>, <code class="code">static</code> or <code class="code">shared</code>. 1755 </p> 1756 <a class="anchor" id="with-included-gettext"></a></dd> 1757 <dt><code class="code">--with-included-gettext</code></dt> 1758 <dd><p>Only available if <samp class="file">gettext</samp> is present in the source tree. 1759 </p> 1760 <p>Forces the gettext tree to be configured to build and use a new static 1761 libintl, overriding the system libintl. Results in GCC being built 1762 against the newly built libintl rather than the system libintl. 1763 </p> 1764 <p>The build system makes a somewhat complicated choice when picking where 1765 to get gettext routines from. The following table is a summary of the 1766 possible options: 1767 </p> 1768 <table class="multitable"> 1769 <thead><tr><th width="12%">GNU gettext present in sources</th><th width="12%">libintl installed on the system</th><th width="12%"><code class="code">gettext</code> present in libc</th><th width="20%"><code class="code">--with-included-gettext</code></th><th width="44%">Effects on localization</th></tr></thead> 1770 <tbody><tr><td width="12%">No</td><td width="12%">No</td><td width="12%">No</td><td width="20%">(ignored)</td><td width="44%">No localization</td></tr> 1771 <tr><td width="12%">No</td><td width="12%">No</td><td width="12%">Yes</td><td width="20%">(ignored)</td><td width="44%">Localized, libc gettext</td></tr> 1772 <tr><td width="12%">No</td><td width="12%">Yes</td><td width="12%">No</td><td width="20%">(ignored)</td><td width="44%">Localized, libintl</td></tr> 1773 <tr><td width="12%">No</td><td width="12%">Yes</td><td width="12%">Yes</td><td width="20%">(ignored)</td><td width="44%">Localized, libintl</td></tr> 1774 <tr><td width="12%">Yes</td><td width="12%">No</td><td width="12%">No</td><td width="20%">No</td><td width="44%">Localized, new, static libintl</td></tr> 1775 <tr><td width="12%">Yes</td><td width="12%">No</td><td width="12%">No</td><td width="20%">Yes</td><td width="44%">Localized, new, static libintl</td></tr> 1776 <tr><td width="12%">Yes</td><td width="12%">No</td><td width="12%">Yes</td><td width="20%">No</td><td width="44%">Localized, libc gettext</td></tr> 1777 <tr><td width="12%">Yes</td><td width="12%">No</td><td width="12%">Yes</td><td width="20%">Yes</td><td width="44%">Localized, new, static libintl</td></tr> 1778 <tr><td width="12%">Yes</td><td width="12%">Yes</td><td width="12%">No</td><td width="20%">No</td><td width="44%">Localized, libintl</td></tr> 1779 <tr><td width="12%">Yes</td><td width="12%">Yes</td><td width="12%">No</td><td width="20%">Yes</td><td width="44%">Localized, new, static libintl</td></tr> 1780 <tr><td width="12%">Yes</td><td width="12%">Yes</td><td width="12%">Yes</td><td width="20%">No</td><td width="44%">Localized, libintl</td></tr> 1781 <tr><td width="12%">Yes</td><td width="12%">Yes</td><td width="12%">Yes</td><td width="20%">Yes</td><td width="44%">Localized, new, static libintl</td></tr> 1782 </tbody> 1783 </table> 1784 1785 </dd> 1786 <dt><code class="code">--with-catgets</code></dt> 1787 <dd><p>If NLS is enabled, and if the host lacks <code class="code">gettext</code> but has the 1788 inferior <code class="code">catgets</code> interface, the GCC build procedure normally 1789 ignores <code class="code">catgets</code> and instead uses GCC’s copy of the GNU 1790 <code class="code">gettext</code> library. The <samp class="option">--with-catgets</samp> option causes the 1791 build procedure to use the host’s <code class="code">catgets</code> in this situation. 1792 </p> 1793 </dd> 1794 <dt><code class="code">--with-libiconv-prefix=<var class="var">dir</var></code></dt> 1795 <dd><p>Search for libiconv header files in <samp class="file"><var class="var">dir</var>/include</samp> and 1796 libiconv library files in <samp class="file"><var class="var">dir</var>/lib</samp>. 1797 </p> 1798 </dd> 1799 <dt><code class="code">--enable-obsolete</code></dt> 1800 <dd><p>Enable configuration for an obsoleted system. If you attempt to 1801 configure GCC for a system (build, host, or target) which has been 1802 obsoleted, and you do not specify this flag, configure will halt with an 1803 error message. 1804 </p> 1805 <p>All support for systems which have been obsoleted in one release of GCC 1806 is removed entirely in the next major release, unless someone steps 1807 forward to maintain the port. 1808 </p> 1809 </dd> 1810 <dt><code class="code">--enable-decimal-float</code></dt> 1811 <dt><code class="code">--enable-decimal-float=yes</code></dt> 1812 <dt><code class="code">--enable-decimal-float=no</code></dt> 1813 <dt><code class="code">--enable-decimal-float=bid</code></dt> 1814 <dt><code class="code">--enable-decimal-float=dpd</code></dt> 1815 <dt><code class="code">--disable-decimal-float</code></dt> 1816 <dd><p>Enable (or disable) support for the C decimal floating point extension 1817 that is in the IEEE 754-2008 standard. This is enabled by default 1818 only on AArch64, PowerPC, i386, and x86_64 GNU/Linux systems. Other 1819 systems may also support it, but require the user to specifically 1820 enable it. You can optionally control which decimal floating point 1821 format is used (either ‘<samp class="samp">bid</samp>’ or ‘<samp class="samp">dpd</samp>’). The ‘<samp class="samp">bid</samp>’ 1822 (binary integer decimal) format is default on AArch64, i386 and x86_64 1823 systems, and the ‘<samp class="samp">dpd</samp>’ (densely packed decimal) format is default 1824 on PowerPC systems. 1825 </p> 1826 </dd> 1827 <dt><code class="code">--enable-fixed-point</code></dt> 1828 <dt><code class="code">--disable-fixed-point</code></dt> 1829 <dd><p>Enable (or disable) support for C fixed-point arithmetic. 1830 This option is enabled by default for some targets (such as MIPS) which 1831 have hardware-support for fixed-point operations. On other targets, you 1832 may enable this option manually. 1833 </p> 1834 </dd> 1835 <dt><code class="code">--with-long-double-128</code></dt> 1836 <dd><p>Specify if <code class="code">long double</code> type should be 128-bit by default on selected 1837 GNU/Linux architectures. If using <code class="code">--without-long-double-128</code>, 1838 <code class="code">long double</code> will be by default 64-bit, the same as <code class="code">double</code> type. 1839 When neither of these configure options are used, the default will be 1840 128-bit <code class="code">long double</code> when built against GNU C Library 2.4 and later, 1841 64-bit <code class="code">long double</code> otherwise. 1842 </p> 1843 </dd> 1844 <dt><code class="code">--with-long-double-format=ibm</code></dt> 1845 <dt><code class="code">--with-long-double-format=ieee</code></dt> 1846 <dd><p>Specify whether <code class="code">long double</code> uses the IBM extended double format 1847 or the IEEE 128-bit floating point format on PowerPC Linux systems. 1848 This configuration switch will only work on little endian PowerPC 1849 Linux systems and on big endian 64-bit systems where the default cpu 1850 is at least power7 (i.e. <samp class="option">--with-cpu=power7</samp>, 1851 <samp class="option">--with-cpu=power8</samp>, or <samp class="option">--with-cpu=power9</samp> is used). 1852 </p> 1853 <p>If you use the <samp class="option">--with-long-double-64</samp> configuration option, 1854 the <samp class="option">--with-long-double-format=ibm</samp> and 1855 <samp class="option">--with-long-double-format=ieee</samp> options are ignored. 1856 </p> 1857 <p>The default <code class="code">long double</code> format is to use IBM extended double. 1858 Until all of the libraries are converted to use IEEE 128-bit floating 1859 point, it is not recommended to use 1860 <samp class="option">--with-long-double-format=ieee</samp>. 1861 </p> 1862 </dd> 1863 <dt><code class="code">--enable-fdpic</code></dt> 1864 <dd><p>On SH Linux systems, generate ELF FDPIC code. 1865 </p> 1866 </dd> 1867 <dt><code class="code">--with-gmp=<var class="var">pathname</var></code></dt> 1868 <dt><code class="code">--with-gmp-include=<var class="var">pathname</var></code></dt> 1869 <dt><code class="code">--with-gmp-lib=<var class="var">pathname</var></code></dt> 1870 <dt><code class="code">--with-mpfr=<var class="var">pathname</var></code></dt> 1871 <dt><code class="code">--with-mpfr-include=<var class="var">pathname</var></code></dt> 1872 <dt><code class="code">--with-mpfr-lib=<var class="var">pathname</var></code></dt> 1873 <dt><code class="code">--with-mpc=<var class="var">pathname</var></code></dt> 1874 <dt><code class="code">--with-mpc-include=<var class="var">pathname</var></code></dt> 1875 <dt><code class="code">--with-mpc-lib=<var class="var">pathname</var></code></dt> 1876 <dd><p>If you want to build GCC but do not have the GMP library, the MPFR 1877 library and/or the MPC library installed in a standard location and 1878 do not have their sources present in the GCC source tree then you 1879 can explicitly specify the directory where they are installed 1880 (‘<samp class="samp">--with-gmp=<var class="var">gmpinstalldir</var></samp>’, 1881 ‘<samp class="samp">--with-mpfr=<var class="var">mpfrinstalldir</var></samp>’, 1882 ‘<samp class="samp">--with-mpc=<var class="var">mpcinstalldir</var></samp>’). The 1883 <samp class="option">--with-gmp=<var class="var">gmpinstalldir</var></samp> option is shorthand for 1884 <samp class="option">--with-gmp-lib=<var class="var">gmpinstalldir</var>/lib</samp> and 1885 <samp class="option">--with-gmp-include=<var class="var">gmpinstalldir</var>/include</samp>. Likewise the 1886 <samp class="option">--with-mpfr=<var class="var">mpfrinstalldir</var></samp> option is shorthand for 1887 <samp class="option">--with-mpfr-lib=<var class="var">mpfrinstalldir</var>/lib</samp> and 1888 <samp class="option">--with-mpfr-include=<var class="var">mpfrinstalldir</var>/include</samp>, also the 1889 <samp class="option">--with-mpc=<var class="var">mpcinstalldir</var></samp> option is shorthand for 1890 <samp class="option">--with-mpc-lib=<var class="var">mpcinstalldir</var>/lib</samp> and 1891 <samp class="option">--with-mpc-include=<var class="var">mpcinstalldir</var>/include</samp>. If these 1892 shorthand assumptions are not correct, you can use the explicit 1893 include and lib options directly. You might also need to ensure the 1894 shared libraries can be found by the dynamic linker when building and 1895 using GCC, for example by setting the runtime shared library path 1896 variable (<code class="env">LD_LIBRARY_PATH</code> on GNU/Linux and Solaris systems). 1897 </p> 1898 <p>These flags are applicable to the host platform only. When building 1899 a cross compiler, they will not be used to configure target libraries. 1900 </p> 1901 </dd> 1902 <dt><code class="code">--with-isl=<var class="var">pathname</var></code></dt> 1903 <dt><code class="code">--with-isl-include=<var class="var">pathname</var></code></dt> 1904 <dt><code class="code">--with-isl-lib=<var class="var">pathname</var></code></dt> 1905 <dd><p>If you do not have the isl library installed in a standard location and you 1906 want to build GCC, you can explicitly specify the directory where it is 1907 installed (‘<samp class="samp">--with-isl=<var class="var">islinstalldir</var></samp>’). The 1908 <samp class="option">--with-isl=<var class="var">islinstalldir</var></samp> option is shorthand for 1909 <samp class="option">--with-isl-lib=<var class="var">islinstalldir</var>/lib</samp> and 1910 <samp class="option">--with-isl-include=<var class="var">islinstalldir</var>/include</samp>. If this 1911 shorthand assumption is not correct, you can use the explicit 1912 include and lib options directly. 1913 </p> 1914 <p>These flags are applicable to the host platform only. When building 1915 a cross compiler, they will not be used to configure target libraries. 1916 </p> 1917 </dd> 1918 <dt><code class="code">--with-stage1-ldflags=<var class="var">flags</var></code></dt> 1919 <dd><p>This option may be used to set linker flags to be used when linking 1920 stage 1 of GCC. These are also used when linking GCC if configured with 1921 <samp class="option">--disable-bootstrap</samp>. If <samp class="option">--with-stage1-libs</samp> is not set to a 1922 value, then the default is ‘<samp class="samp">-static-libstdc++ -static-libgcc</samp>’, if 1923 supported. 1924 </p> 1925 </dd> 1926 <dt><code class="code">--with-stage1-libs=<var class="var">libs</var></code></dt> 1927 <dd><p>This option may be used to set libraries to be used when linking stage 1 1928 of GCC. These are also used when linking GCC if configured with 1929 <samp class="option">--disable-bootstrap</samp>. 1930 </p> 1931 </dd> 1932 <dt><code class="code">--with-boot-ldflags=<var class="var">flags</var></code></dt> 1933 <dd><p>This option may be used to set linker flags to be used when linking 1934 stage 2 and later when bootstrapping GCC. If –with-boot-libs 1935 is not is set to a value, then the default is 1936 ‘<samp class="samp">-static-libstdc++ -static-libgcc</samp>’. 1937 </p> 1938 </dd> 1939 <dt><code class="code">--with-boot-libs=<var class="var">libs</var></code></dt> 1940 <dd><p>This option may be used to set libraries to be used when linking stage 2 1941 and later when bootstrapping GCC. 1942 </p> 1943 </dd> 1944 <dt><code class="code">--with-debug-prefix-map=<var class="var">map</var></code></dt> 1945 <dd><p>Convert source directory names using <samp class="option">-fdebug-prefix-map</samp> when 1946 building runtime libraries. ‘<samp class="samp"><var class="var">map</var></samp>’ is a space-separated 1947 list of maps of the form ‘<samp class="samp"><var class="var">old</var>=<var class="var">new</var></samp>’. 1948 </p> 1949 </dd> 1950 <dt><code class="code">--enable-linker-build-id</code></dt> 1951 <dd><p>Tells GCC to pass <samp class="option">--build-id</samp> option to the linker for all final 1952 links (links performed without the <samp class="option">-r</samp> or <samp class="option">--relocatable</samp> 1953 option), if the linker supports it. If you specify 1954 <samp class="option">--enable-linker-build-id</samp>, but your linker does not 1955 support <samp class="option">--build-id</samp> option, a warning is issued and the 1956 <samp class="option">--enable-linker-build-id</samp> option is ignored. The default is off. 1957 </p> 1958 </dd> 1959 <dt><code class="code">--with-linker-hash-style=<var class="var">choice</var></code></dt> 1960 <dd><p>Tells GCC to pass <samp class="option">--hash-style=<var class="var">choice</var></samp> option to the 1961 linker for all final links. <var class="var">choice</var> can be one of 1962 ‘<samp class="samp">sysv</samp>’, ‘<samp class="samp">gnu</samp>’, and ‘<samp class="samp">both</samp>’ where ‘<samp class="samp">sysv</samp>’ is the default. 1963 </p> 1964 </dd> 1965 <dt><code class="code">--enable-gnu-unique-object</code></dt> 1966 <dt><code class="code">--disable-gnu-unique-object</code></dt> 1967 <dd><p>Tells GCC to use the gnu_unique_object relocation for C++ template 1968 static data members and inline function local statics. Enabled by 1969 default for a toolchain with an assembler that accepts it and 1970 GLIBC 2.11 or above, otherwise disabled. 1971 </p> 1972 </dd> 1973 <dt><code class="code">--with-diagnostics-color=<var class="var">choice</var></code></dt> 1974 <dd><p>Tells GCC to use <var class="var">choice</var> as the default for <samp class="option">-fdiagnostics-color=</samp> 1975 option (if not used explicitly on the command line). <var class="var">choice</var> 1976 can be one of ‘<samp class="samp">never</samp>’, ‘<samp class="samp">auto</samp>’, ‘<samp class="samp">always</samp>’, and ‘<samp class="samp">auto-if-env</samp>’ 1977 where ‘<samp class="samp">auto</samp>’ is the default. ‘<samp class="samp">auto-if-env</samp>’ makes 1978 <samp class="option">-fdiagnostics-color=auto</samp> the default if <code class="env">GCC_COLORS</code> 1979 is present and non-empty in the environment of the compiler, and 1980 <samp class="option">-fdiagnostics-color=never</samp> otherwise. 1981 </p> 1982 </dd> 1983 <dt><code class="code">--with-diagnostics-urls=<var class="var">choice</var></code></dt> 1984 <dd><p>Tells GCC to use <var class="var">choice</var> as the default for <samp class="option">-fdiagnostics-urls=</samp> 1985 option (if not used explicitly on the command line). <var class="var">choice</var> 1986 can be one of ‘<samp class="samp">never</samp>’, ‘<samp class="samp">auto</samp>’, ‘<samp class="samp">always</samp>’, and ‘<samp class="samp">auto-if-env</samp>’ 1987 where ‘<samp class="samp">auto</samp>’ is the default. ‘<samp class="samp">auto-if-env</samp>’ makes 1988 <samp class="option">-fdiagnostics-urls=auto</samp> the default if <code class="env">GCC_URLS</code> 1989 or <code class="env">TERM_URLS</code> is present and non-empty in the environment of the 1990 compiler, and <samp class="option">-fdiagnostics-urls=never</samp> otherwise. 1991 </p> 1992 </dd> 1993 <dt><code class="code">--enable-lto</code></dt> 1994 <dt><code class="code">--disable-lto</code></dt> 1995 <dd><p>Enable support for link-time optimization (LTO). This is enabled by 1996 default, and may be disabled using <samp class="option">--disable-lto</samp>. 1997 </p> 1998 </dd> 1999 <dt><code class="code">--enable-linker-plugin-configure-flags=FLAGS</code></dt> 2000 <dt><code class="code">--enable-linker-plugin-flags=FLAGS</code></dt> 2001 <dd><p>By default, linker plugins (such as the LTO plugin) are built for the 2002 host system architecture. For the case that the linker has a 2003 different (but run-time compatible) architecture, these flags can be 2004 specified to build plugins that are compatible to the linker. For 2005 example, if you are building GCC for a 64-bit x86_64 2006 (‘<samp class="samp">x86_64-pc-linux-gnu</samp>’) host system, but have a 32-bit x86 2007 GNU/Linux (‘<samp class="samp">i686-pc-linux-gnu</samp>’) linker executable (which is 2008 executable on the former system), you can configure GCC as follows for 2009 getting compatible linker plugins: 2010 </p> 2011 <div class="example smallexample"> 2012 <pre class="example-preformatted">% <var class="var">srcdir</var>/configure \ 2013 --host=x86_64-pc-linux-gnu \ 2014 --enable-linker-plugin-configure-flags=--host=i686-pc-linux-gnu \ 2015 --enable-linker-plugin-flags='CC=gcc\ -m32\ -Wl,-rpath,[...]/i686-pc-linux-gnu/lib' 2016 </pre></div> 2017 2018 </dd> 2019 <dt><code class="code">--with-plugin-ld=<var class="var">pathname</var></code></dt> 2020 <dd><p>Enable an alternate linker to be used at link-time optimization (LTO) 2021 link time when <samp class="option">-fuse-linker-plugin</samp> is enabled. 2022 This linker should have plugin support such as gold starting with 2023 version 2.20 or GNU ld starting with version 2.21. 2024 See <samp class="option">-fuse-linker-plugin</samp> for details. 2025 </p> 2026 </dd> 2027 <dt><code class="code">--enable-canonical-system-headers</code></dt> 2028 <dt><code class="code">--disable-canonical-system-headers</code></dt> 2029 <dd><p>Enable system header path canonicalization for <samp class="file">libcpp</samp>. This can 2030 produce shorter header file paths in diagnostics and dependency output 2031 files, but these changed header paths may conflict with some compilation 2032 environments. Enabled by default, and may be disabled using 2033 <samp class="option">--disable-canonical-system-headers</samp>. 2034 </p> 2035 </dd> 2036 <dt><code class="code">--with-glibc-version=<var class="var">major</var>.<var class="var">minor</var></code></dt> 2037 <dd><p>Tell GCC that when the GNU C Library (glibc) is used on the target it 2038 will be version <var class="var">major</var>.<var class="var">minor</var> or later. Normally this can 2039 be detected from the C library’s header files, but this option may be 2040 needed when bootstrapping a cross toolchain without the header files 2041 available for building the initial bootstrap compiler. 2042 </p> 2043 <p>If GCC is configured with some multilibs that use glibc and some that 2044 do not, this option applies only to the multilibs that use glibc. 2045 However, such configurations may not work well as not all the relevant 2046 configuration in GCC is on a per-multilib basis. 2047 </p> 2048 </dd> 2049 <dt><code class="code">--enable-as-accelerator-for=<var class="var">target</var></code></dt> 2050 <dd><p>Build as offload target compiler. Specify offload host triple by <var class="var">target</var>. 2051 </p> 2052 </dd> 2053 <dt><code class="code">--enable-offload-targets=<var class="var">target1</var>[=<var class="var">path1</var>],…,<var class="var">targetN</var>[=<var class="var">pathN</var>]</code></dt> 2054 <dd><p>Enable offloading to targets <var class="var">target1</var>, …, <var class="var">targetN</var>. 2055 Offload compilers are expected to be already installed. Default search 2056 path for them is <samp class="file"><var class="var">exec-prefix</var></samp>, but it can be changed by 2057 specifying paths <var class="var">path1</var>, …, <var class="var">pathN</var>. 2058 </p> 2059 <div class="example smallexample"> 2060 <pre class="example-preformatted">% <var class="var">srcdir</var>/configure \ 2061 --enable-offload-targets=amdgcn-amdhsa,nvptx-none 2062 </pre></div> 2063 2064 </dd> 2065 <dt><code class="code">--enable-offload-defaulted</code></dt> 2066 <dd> 2067 <p>Tell GCC that configured but not installed offload compilers and libgomp 2068 plugins are silently ignored. Useful for distribution compilers where 2069 those are in separate optional packages and where the presence or absence 2070 of those optional packages should determine the actual supported offloading 2071 target set rather than the GCC configure-time selection. 2072 </p> 2073 </dd> 2074 <dt><code class="code">--enable-cet</code></dt> 2075 <dt><code class="code">--disable-cet</code></dt> 2076 <dd><p>Enable building target run-time libraries with control-flow 2077 instrumentation, see <samp class="option">-fcf-protection</samp> option. When 2078 <code class="code">--enable-cet</code> is specified target libraries are configured 2079 to add <samp class="option">-fcf-protection</samp> and, if needed, other target 2080 specific options to a set of building options. 2081 </p> 2082 <p><code class="code">--enable-cet=auto</code> is default. CET is enabled on Linux/x86 if 2083 target binutils supports <code class="code">Intel CET</code> instructions and disabled 2084 otherwise. In this case, the target libraries are configured to get 2085 additional <samp class="option">-fcf-protection</samp> option. 2086 </p> 2087 </dd> 2088 <dt><code class="code">--with-riscv-attribute=‘<samp class="samp">yes</samp>’, ‘<samp class="samp">no</samp>’ or ‘<samp class="samp">default</samp>’</code></dt> 2089 <dd><p>Generate RISC-V attribute by default, in order to record extra build 2090 information in object. 2091 </p> 2092 <p>The option is disabled by default. It is enabled on RISC-V/ELF (bare-metal) 2093 target if target binutils supported. 2094 </p> 2095 </dd> 2096 <dt><code class="code">--enable-s390-excess-float-precision</code></dt> 2097 <dt><code class="code">--disable-s390-excess-float-precision</code></dt> 2098 <dd><p>On s390(x) targets, enable treatment of float expressions with double precision 2099 when in standards-compliant mode (e.g., when <code class="code">--std=c99</code> or 2100 <code class="code">-fexcess-precision=standard</code> are given). 2101 </p> 2102 <p>For a native build and cross compiles that have target headers, the option’s 2103 default is derived from glibc’s behavior. When glibc clamps float_t to double, 2104 GCC follows and enables the option. For other cross compiles, the default is 2105 disabled. 2106 </p> 2107 </dd> 2108 <dt><code class="code">--with-zstd=<var class="var">pathname</var></code></dt> 2109 <dt><code class="code">--with-zstd-include=<var class="var">pathname</var></code></dt> 2110 <dt><code class="code">--with-zstd-lib=<var class="var">pathname</var></code></dt> 2111 <dd><p>If you do not have the <code class="code">zstd</code> library installed in a standard 2112 location and you want to build GCC, you can explicitly specify the 2113 directory where it is installed (‘<samp class="samp">--with-zstd=<var class="var">zstdinstalldir</var></samp>’). 2114 The <samp class="option">--with-zstd=<var class="var">zstdinstalldir</var></samp> option is shorthand for 2115 <samp class="option">--with-zstd-lib=<var class="var">zstdinstalldir</var>/lib</samp> and 2116 <samp class="option">--with-zstd-include=<var class="var">zstdinstalldir</var>/include</samp>. If this 2117 shorthand assumption is not correct, you can use the explicit 2118 include and lib options directly. 2119 </p> 2120 <p>These flags are applicable to the host platform only. When building 2121 a cross compiler, they will not be used to configure target libraries. 2122 </p></dd> 2123 </dl> 2124 2125 <h4 class="subheading" id="Cross-Compiler-Specific-Options"><span>Cross-Compiler-Specific Options<a class="copiable-link" href="#Cross-Compiler-Specific-Options"> ¶</a></span></h4> 2126 <p>The following options only apply to building cross compilers. 2127 </p> 2128 <dl class="table"> 2129 <dt><code class="code">--with-toolexeclibdir=<var class="var">dir</var></code></dt> 2130 <dd><p>Specify the installation directory for libraries built with a cross compiler. 2131 The default is <samp class="option">${gcc_tooldir}/lib</samp>. 2132 </p> 2133 </dd> 2134 <dt><code class="code">--with-sysroot</code></dt> 2135 <dt><code class="code">--with-sysroot=<var class="var">dir</var></code></dt> 2136 <dd><p>Tells GCC to consider <var class="var">dir</var> as the root of a tree that contains 2137 (a subset of) the root filesystem of the target operating system. 2138 Target system headers, libraries and run-time object files will be 2139 searched for in there. More specifically, this acts as if 2140 <samp class="option">--sysroot=<var class="var">dir</var></samp> was added to the default options of the built 2141 compiler. The specified directory is not copied into the 2142 install tree, unlike the options <samp class="option">--with-headers</samp> and 2143 <samp class="option">--with-libs</samp> that this option obsoletes. The default value, 2144 in case <samp class="option">--with-sysroot</samp> is not given an argument, is 2145 <samp class="option">${gcc_tooldir}/sys-root</samp>. If the specified directory is a 2146 subdirectory of <samp class="option">${exec_prefix}</samp>, then it will be found relative to 2147 the GCC binaries if the installation tree is moved. 2148 </p> 2149 <p>This option affects the system root for the compiler used to build 2150 target libraries (which runs on the build system) and the compiler newly 2151 installed with <code class="code">make install</code>; it does not affect the compiler which is 2152 used to build GCC itself. 2153 </p> 2154 <p>If you specify the <samp class="option">--with-native-system-header-dir=<var class="var">dirname</var></samp> 2155 option then the compiler will search that directory within <var class="var">dirname</var> for 2156 native system headers rather than the default <samp class="file">/usr/include</samp>. 2157 </p> 2158 </dd> 2159 <dt><code class="code">--with-build-sysroot</code></dt> 2160 <dt><code class="code">--with-build-sysroot=<var class="var">dir</var></code></dt> 2161 <dd><p>Tells GCC to consider <var class="var">dir</var> as the system root (see 2162 <samp class="option">--with-sysroot</samp>) while building target libraries, instead of 2163 the directory specified with <samp class="option">--with-sysroot</samp>. This option is 2164 only useful when you are already using <samp class="option">--with-sysroot</samp>. You 2165 can use <samp class="option">--with-build-sysroot</samp> when you are configuring with 2166 <samp class="option">--prefix</samp> set to a directory that is different from the one in 2167 which you are installing GCC and your target libraries. 2168 </p> 2169 <p>This option affects the system root for the compiler used to build 2170 target libraries (which runs on the build system); it does not affect 2171 the compiler which is used to build GCC itself. 2172 </p> 2173 <p>If you specify the <samp class="option">--with-native-system-header-dir=<var class="var">dirname</var></samp> 2174 option then the compiler will search that directory within <var class="var">dirname</var> for 2175 native system headers rather than the default <samp class="file">/usr/include</samp>. 2176 </p> 2177 </dd> 2178 <dt><code class="code">--with-headers</code></dt> 2179 <dt><code class="code">--with-headers=<var class="var">dir</var></code></dt> 2180 <dd><p>Deprecated in favor of <samp class="option">--with-sysroot</samp>. 2181 Specifies that target headers are available when building a cross compiler. 2182 The <var class="var">dir</var> argument specifies a directory which has the target include 2183 files. These include files will be copied into the <samp class="file">gcc</samp> install 2184 directory. <em class="emph">This option with the <var class="var">dir</var> argument is required</em> when 2185 building a cross compiler, if <samp class="file"><var class="var">prefix</var>/<var class="var">target</var>/sys-include</samp> 2186 doesn’t pre-exist. If <samp class="file"><var class="var">prefix</var>/<var class="var">target</var>/sys-include</samp> does 2187 pre-exist, the <var class="var">dir</var> argument may be omitted. <code class="command">fixincludes</code> 2188 will be run on these files to make them compatible with GCC. 2189 </p> 2190 </dd> 2191 <dt><code class="code">--without-headers</code></dt> 2192 <dd><p>Tells GCC not use any target headers from a libc when building a cross 2193 compiler. When crossing to GNU/Linux, you need the headers so GCC 2194 can build the exception handling for libgcc. 2195 </p> 2196 </dd> 2197 <dt><code class="code">--with-libs</code></dt> 2198 <dt><code class="code">--with-libs="<var class="var">dir1</var> <var class="var">dir2</var> … <var class="var">dirN</var>"</code></dt> 2199 <dd><p>Deprecated in favor of <samp class="option">--with-sysroot</samp>. 2200 Specifies a list of directories which contain the target runtime 2201 libraries. These libraries will be copied into the <samp class="file">gcc</samp> install 2202 directory. If the directory list is omitted, this option has no 2203 effect. 2204 </p> 2205 </dd> 2206 <dt><code class="code">--with-newlib</code></dt> 2207 <dd><p>Specifies that ‘<samp class="samp">newlib</samp>’ is 2208 being used as the target C library. This causes <code class="code">__eprintf</code> to be 2209 omitted from <samp class="file">libgcc.a</samp> on the assumption that it will be provided by 2210 ‘<samp class="samp">newlib</samp>’. 2211 </p> 2212 <a name="avr"></a> 2213 </dd> 2214 <dt><code class="code">--with-avrlibc</code></dt> 2215 <dd><p>Only supported for the AVR target. Specifies that ‘<samp class="samp">AVR-Libc</samp>’ is 2216 being used as the target C library. This causes float support 2217 functions like <code class="code">__addsf3</code> to be omitted from <samp class="file">libgcc.a</samp> on 2218 the assumption that it will be provided by <samp class="file">libm.a</samp>. For more 2219 technical details, cf. <a class="uref" href="https://gcc.gnu.org/PR54461">PR54461</a>. 2220 It is not supported for 2221 RTEMS configurations, which currently use newlib. The option is 2222 supported since version 4.7.2 and is the default in 4.8.0 and newer. 2223 </p> 2224 </dd> 2225 <dt><code class="code">--with-double={32|64|32,64|64,32}</code></dt> 2226 <dt><code class="code">--with-long-double={32|64|32,64|64,32|double}</code></dt> 2227 <dd><p>Only supported for the AVR target since version 10. 2228 Specify the default layout available for the C/C++ ‘<samp class="samp">double</samp>’ 2229 and ‘<samp class="samp">long double</samp>’ type, respectively. The following rules apply: 2230 </p><ul class="itemize mark-bullet"> 2231 <li>The first value after the ‘<samp class="samp">=</samp>’ specifies the default layout (in bits) 2232 of the type and also the default for the <samp class="option">-mdouble=</samp> resp. 2233 <samp class="option">-mlong-double=</samp> compiler option. 2234 </li><li>If more than one value is specified, respective multilib variants are 2235 available, and <samp class="option">-mdouble=</samp> resp. <samp class="option">-mlong-double=</samp> acts 2236 as a multilib option. 2237 </li><li>If <samp class="option">--with-long-double=double</samp> is specified, ‘<samp class="samp">double</samp>’ and 2238 ‘<samp class="samp">long double</samp>’ will have the same layout. 2239 </li><li>The defaults are <samp class="option">--with-long-double=64,32</samp> and 2240 <samp class="option">--with-double=32,64</samp>. The default ‘<samp class="samp">double</samp>’ layout imposed by 2241 the latter is compatible with older versions of the compiler that implement 2242 ‘<samp class="samp">double</samp>’ as a 32-bit type, which does not comply to the language standard. 2243 </li></ul> 2244 <p>Not all combinations of <samp class="option">--with-double=</samp> and 2245 <samp class="option">--with-long-double=</samp> are valid. For example, the combination 2246 <samp class="option">--with-double=32,64</samp> <samp class="option">--with-long-double=32</samp> will be 2247 rejected because the first option specifies the availability of 2248 multilibs for ‘<samp class="samp">double</samp>’, whereas the second option implies 2249 that ‘<samp class="samp">long double</samp>’ — and hence also ‘<samp class="samp">double</samp>’ — is always 2250 32 bits wide. 2251 </p> 2252 </dd> 2253 <dt><code class="code">--with-double-comparison={tristate|bool|libf7}</code></dt> 2254 <dd><p>Only supported for the AVR target since version 10. 2255 Specify what result format is returned by library functions that 2256 compare 64-bit floating point values (<code class="code">DFmode</code>). 2257 The GCC default is ‘<samp class="samp">tristate</samp>’. If the floating point 2258 implementation returns a boolean instead, set it to ‘<samp class="samp">bool</samp>’. 2259 </p> 2260 </dd> 2261 <dt><code class="code">--with-libf7={libgcc|math|math-symbols|no}</code></dt> 2262 <dd><p>Only supported for the AVR target since version 10. 2263 Specify to which degree code from LibF7 is included in libgcc. 2264 LibF7 is an ad-hoc, AVR-specific, 64-bit floating point emulation 2265 written in C and (inline) assembly. ‘<samp class="samp">libgcc</samp>’ adds support 2266 for functions that one would usually expect in libgcc like double addition, 2267 double comparisons and double conversions. ‘<samp class="samp">math</samp>’ also adds routines 2268 that one would expect in <samp class="file">libm.a</samp>, but with <code class="code">__</code> (two underscores) 2269 prepended to the symbol names as specified by <samp class="file">math.h</samp>. 2270 ‘<samp class="samp">math-symbols</samp>’ also defines weak aliases for the functions 2271 declared in <samp class="file">math.h</samp>. However, <code class="code">--with-libf7</code> won’t 2272 install no <samp class="file">math.h</samp> header file whatsoever, this file must come 2273 from elsewhere. This option sets <samp class="option">--with-double-comparison</samp> 2274 to ‘<samp class="samp">bool</samp>’. 2275 </p> 2276 </dd> 2277 <dt><code class="code">--with-nds32-lib=<var class="var">library</var></code></dt> 2278 <dd><p>Specifies that <var class="var">library</var> setting is used for building <samp class="file">libgcc.a</samp>. 2279 Currently, the valid <var class="var">library</var> is ‘<samp class="samp">newlib</samp>’ or ‘<samp class="samp">mculib</samp>’. 2280 This option is only supported for the NDS32 target. 2281 </p> 2282 </dd> 2283 <dt><code class="code">--with-build-time-tools=<var class="var">dir</var></code></dt> 2284 <dd><p>Specifies where to find the set of target tools (assembler, linker, etc.) 2285 that will be used while building GCC itself. This option can be useful 2286 if the directory layouts are different between the system you are building 2287 GCC on, and the system where you will deploy it. 2288 </p> 2289 <p>For example, on an ‘<samp class="samp">ia64-hp-hpux</samp>’ system, you may have the GNU 2290 assembler and linker in <samp class="file">/usr/bin</samp>, and the native tools in a 2291 different path, and build a toolchain that expects to find the 2292 native tools in <samp class="file">/usr/bin</samp>. 2293 </p> 2294 <p>When you use this option, you should ensure that <var class="var">dir</var> includes 2295 <code class="command">ar</code>, <code class="command">as</code>, <code class="command">ld</code>, <code class="command">nm</code>, 2296 <code class="command">ranlib</code> and <code class="command">strip</code> if necessary, and possibly 2297 <code class="command">objdump</code>. Otherwise, GCC may use an inconsistent set of 2298 tools. 2299 </p></dd> 2300 </dl> 2301 2302 <h4 class="subsubheading" id="Overriding-configure-test-results"><span>Overriding <code class="command">configure</code> test results<a class="copiable-link" href="#Overriding-configure-test-results"> ¶</a></span></h4> 2303 2304 <p>Sometimes, it might be necessary to override the result of some 2305 <code class="command">configure</code> test, for example in order to ease porting to a new 2306 system or work around a bug in a test. The toplevel <code class="command">configure</code> 2307 script provides three variables for this: 2308 </p> 2309 <dl class="table"> 2310 <dt><a id="index-build_005fconfigargs"></a><span><code class="code">build_configargs</code><a class="copiable-link" href="#index-build_005fconfigargs"> ¶</a></span></dt> 2311 <dd><p>The contents of this variable is passed to all build <code class="command">configure</code> 2312 scripts. 2313 </p> 2314 </dd> 2315 <dt><a id="index-host_005fconfigargs"></a><span><code class="code">host_configargs</code><a class="copiable-link" href="#index-host_005fconfigargs"> ¶</a></span></dt> 2316 <dd><p>The contents of this variable is passed to all host <code class="command">configure</code> 2317 scripts. 2318 </p> 2319 </dd> 2320 <dt><a id="index-target_005fconfigargs"></a><span><code class="code">target_configargs</code><a class="copiable-link" href="#index-target_005fconfigargs"> ¶</a></span></dt> 2321 <dd><p>The contents of this variable is passed to all target <code class="command">configure</code> 2322 scripts. 2323 </p> 2324 </dd> 2325 </dl> 2326 2327 <p>In order to avoid shell and <code class="command">make</code> quoting issues for complex 2328 overrides, you can pass a setting for <code class="env">CONFIG_SITE</code> and set 2329 variables in the site file. 2330 </p> 2331 <h4 class="subheading" id="Objective-C-Specific-Options"><span>Objective-C-Specific Options<a class="copiable-link" href="#Objective-C-Specific-Options"> ¶</a></span></h4> 2332 2333 <p>The following options apply to the build of the Objective-C runtime library. 2334 </p> 2335 <dl class="table"> 2336 <dt><code class="code">--enable-objc-gc</code></dt> 2337 <dd><p>Specify that an additional variant of the GNU Objective-C runtime library 2338 is built, using an external build of the Boehm-Demers-Weiser garbage 2339 collector (<a class="uref" href="https://www.hboehm.info/gc/">https://www.hboehm.info/gc/</a>). This library needs to be 2340 available for each multilib variant, unless configured with 2341 <samp class="option">--enable-objc-gc=‘<samp class="samp">auto</samp>’</samp> in which case the build of the 2342 additional runtime library is skipped when not available and the build 2343 continues. 2344 </p> 2345 </dd> 2346 <dt><code class="code">--with-target-bdw-gc=<var class="var">list</var></code></dt> 2347 <dt><code class="code">--with-target-bdw-gc-include=<var class="var">list</var></code></dt> 2348 <dt><code class="code">--with-target-bdw-gc-lib=<var class="var">list</var></code></dt> 2349 <dd><p>Specify search directories for the garbage collector header files and 2350 libraries. <var class="var">list</var> is a comma separated list of key value pairs of the 2351 form ‘<samp class="samp"><var class="var">multilibdir</var>=<var class="var">path</var></samp>’, where the default multilib key 2352 is named as ‘<samp class="samp">.</samp>’ (dot), or is omitted (e.g. 2353 ‘<samp class="samp">--with-target-bdw-gc=/opt/bdw-gc,32=/opt-bdw-gc32</samp>’). 2354 </p> 2355 <p>The options <samp class="option">--with-target-bdw-gc-include</samp> and 2356 <samp class="option">--with-target-bdw-gc-lib</samp> must always be specified together 2357 for each multilib variant and they take precedence over 2358 <samp class="option">--with-target-bdw-gc</samp>. If <samp class="option">--with-target-bdw-gc-include</samp> 2359 is missing values for a multilib, then the value for the default 2360 multilib is used (e.g. ‘<samp class="samp">--with-target-bdw-gc-include=/opt/bdw-gc/include</samp>’ 2361 ‘<samp class="samp">--with-target-bdw-gc-lib=/opt/bdw-gc/lib64,32=/opt-bdw-gc/lib32</samp>’). 2362 If none of these options are specified, the library is assumed in 2363 default locations. 2364 </p></dd> 2365 </dl> 2366 2367 <h4 class="subheading" id="D-Specific-Options"><span>D-Specific Options<a class="copiable-link" href="#D-Specific-Options"> ¶</a></span></h4> 2368 2369 <p>The following options apply to the build of the D runtime library. 2370 </p> 2371 <dl class="table"> 2372 <dt><code class="code">--enable-libphobos-checking</code></dt> 2373 <dt><code class="code">--disable-libphobos-checking</code></dt> 2374 <dt><code class="code">--enable-libphobos-checking=<var class="var">list</var></code></dt> 2375 <dd><p>This option controls whether run-time checks and contracts are compiled into 2376 the D runtime library. When the option is not specified, the library is built 2377 with ‘<samp class="samp">release</samp>’ checking. When the option is specified without a 2378 <var class="var">list</var>, the result is the same as ‘<samp class="samp">--enable-libphobos-checking=yes</samp>’. 2379 Likewise, ‘<samp class="samp">--disable-libphobos-checking</samp>’ is equivalent to 2380 ‘<samp class="samp">--enable-libphobos-checking=no</samp>’. 2381 </p> 2382 <p>The categories of checks available in <var class="var">list</var> are ‘<samp class="samp">yes</samp>’ (compiles 2383 libphobos with <samp class="option">-fno-release</samp>), ‘<samp class="samp">no</samp>’ (compiles libphobos with 2384 <samp class="option">-frelease</samp>), ‘<samp class="samp">all</samp>’ (same as ‘<samp class="samp">yes</samp>’), ‘<samp class="samp">none</samp>’ or 2385 ‘<samp class="samp">release</samp>’ (same as ‘<samp class="samp">no</samp>’). 2386 </p> 2387 <p>Individual checks available in <var class="var">list</var> are ‘<samp class="samp">assert</samp>’ (compiles libphobos 2388 with an extra option <samp class="option">-fassert</samp>). 2389 </p> 2390 </dd> 2391 <dt><code class="code">--with-libphobos-druntime-only</code></dt> 2392 <dt><code class="code">--with-libphobos-druntime-only=<var class="var">choice</var></code></dt> 2393 <dd><p>Specify whether to build only the core D runtime library (druntime), or both 2394 the core and standard library (phobos) into libphobos. This is useful for 2395 targets that have full support in druntime, but no or incomplete support 2396 in phobos. <var class="var">choice</var> can be one of ‘<samp class="samp">auto</samp>’, ‘<samp class="samp">yes</samp>’, and ‘<samp class="samp">no</samp>’ 2397 where ‘<samp class="samp">auto</samp>’ is the default. 2398 </p> 2399 <p>When the option is not specified, the default choice ‘<samp class="samp">auto</samp>’ means that it 2400 is inferred whether the target has support for the phobos standard library. 2401 When the option is specified without a <var class="var">choice</var>, the result is the same as 2402 ‘<samp class="samp">--with-libphobos-druntime-only=yes</samp>’. 2403 </p> 2404 </dd> 2405 <dt><code class="code">--with-target-system-zlib</code></dt> 2406 <dd><p>Use installed ‘<samp class="samp">zlib</samp>’ rather than that included with GCC. This needs 2407 to be available for each multilib variant, unless configured with 2408 <samp class="option">--with-target-system-zlib=‘<samp class="samp">auto</samp>’</samp> in which case the GCC included 2409 ‘<samp class="samp">zlib</samp>’ is only used when the system installed library is not available. 2410 </p></dd> 2411 </dl> 2412 2413 <hr /> 2414 <p> 2415 <p><a class="uref" href="./index.html">Return to the GCC Installation page</a> 2416 </p> 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 </body> 2428 </html> 2429