1 <?xml version="1.0" encoding="ISO-8859-1"?>
2 <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4 <!ENTITY % general-entities SYSTEM "../general.ent">
8 <sect1 id="ch-system-gcc" role="wrap">
9 <?dbhtml filename="gcc.html"?>
11 <sect1info condition="script">
12 <productname>gcc</productname>
13 <productnumber>&gcc-version;</productnumber>
14 <address>&gcc-url;</address>
17 <title>GCC-&gcc-version;</title>
19 <indexterm zone="ch-system-gcc">
20 <primary sortas="a-GCC">GCC</primary>
23 <sect2 role="package">
26 <para>The GCC package contains the GNU compiler collection, which includes
27 the C and C++ compilers.</para>
30 <segtitle>&buildtime;</segtitle>
31 <segtitle>&diskspace;</segtitle>
34 <seg>&gcc-ch6-sbu;</seg>
35 <seg>&gcc-ch6-du;</seg>
41 <sect2 role="installation">
42 <title>Installation of GCC</title>
44 <para>If building on x86_64, change the default directory name for 64-bit
45 libraries to <quote>lib</quote>:</para>
47 <screen><userinput remap="pre">case $(uname -m) in
49 sed -e '/m64=/s/lib64/lib/' \
50 -i.orig gcc/config/i386/t-linux64
52 esac</userinput></screen>
54 <para>The GCC documentation recommends building GCC in a dedicated build directory:</para>
56 <screen><userinput remap="pre">mkdir -v build
57 cd build</userinput></screen>
59 <para>Prepare GCC for compilation:</para>
61 <screen><userinput remap="configure">SED=sed \
62 ../configure --prefix=/usr \
63 --enable-languages=c,c++ \
66 --with-system-zlib</userinput></screen>
68 <para>Note that for other languages, there are some prerequisites that
69 are not yet available. See the
70 <ulink url="&blfs-book;general/gcc.html">BLFS Book</ulink>
71 for instructions on how to build all of GCC's supported languages.</para>
74 <title>The meaning of the new configure parameters:</title>
77 <term><envar>SED=sed</envar></term>
79 <para>Setting this environment variable prevents a hard-coded
80 path to /tools/bin/sed.</para>
85 <term><parameter>- -disable-libmpx</parameter></term>
87 <para>This switch tells GCC to not build mpx (Memory Protection
88 Extensions) that can cause problems on some processors. It has
89 been removed from the next version of gcc.</para>
94 <term><parameter>--with-system-zlib</parameter></term>
96 <para>This switch tells GCC to link to the system installed copy of
97 the Zlib library, rather than its own internal copy.</para>
102 <para>Compile the package:</para>
104 <screen><userinput remap="make">make</userinput></screen>
107 <para>In this section, the test suite for GCC is considered
108 critical. Do not skip it under any circumstance.</para>
111 <para>One set of tests in the GCC test suite is known to exhaust the stack,
112 so increase the stack size prior to running the tests:</para>
114 <screen><userinput remap="test">ulimit -s 32768</userinput></screen>
116 <para>Test the results as a non-privileged user, but do not stop at errors:</para>
118 <screen><userinput remap="test">chown -Rv nobody .
119 su nobody -s /bin/bash -c "PATH=$PATH make -k check"</userinput></screen>
121 <para>To receive a summary of the test suite results, run:</para>
123 <screen><userinput remap="test">../contrib/test_summary</userinput></screen>
125 <para>For only the summaries, pipe the output through
126 <userinput>grep -A7 Summ</userinput>.</para>
128 <para>Results can be compared with those located at <ulink
129 url="&test-results;"/> and
130 <ulink url="https://gcc.gnu.org/ml/gcc-testresults/"/>.</para>
132 <para>Six tests related to get_time are known to fail. These are
133 apparently related to the en_HK locale.</para>
135 <para>Two tests named lookup.cc and reverse.cc in experimental/net
136 are known to fail in LFS chroot environment because they require
137 /etc/hosts and iana-etc.</para>
139 <para>Two tests named pr57193.c and pr90178.c are known to fail.</para>
141 <para>A few unexpected failures cannot always be avoided. The GCC developers
142 are usually aware of these issues, but have not resolved them yet.
143 Unless the test results are vastly different from those at the above URL,
144 it is safe to continue.</para>
147 On some combinations of kernel configuration and AMD processors
148 there may be more than 1100 failures in the gcc.target/i386/mpx
149 tests (which are designed to test the MPX option on recent
150 Intel processors). These can safely be ignored on AMD
151 processors. These tests will also fail on Intel processors if MPX support
152 is not enabled in the kernel even though it is present on the CPU.
155 <para>Install the package and remove an unneeded directory:</para>
157 <screen><userinput remap="install">make install
158 rm -rf /usr/lib/gcc/$(gcc -dumpmachine)/&gcc-version;/include-fixed/bits/</userinput></screen>
160 <para>The GCC build directory is owned by <systemitem class="username">
161 nobody</systemitem> now and the ownership of the installed header
162 directory (and its content) will be incorrect. Change the ownership to
163 <systemitem class="username">root</systemitem> user and group:</para>
165 <screen><userinput remap="install">chown -v -R root:root \
166 /usr/lib/gcc/*linux-gnu/&gcc-version;/include{,-fixed}</userinput></screen>
168 <para>Create a symlink required by the <ulink
169 url="https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s09.html">FHS</ulink>
170 for "historical" reasons.</para>
172 <screen><userinput remap="install">ln -sv ../usr/bin/cpp /lib</userinput></screen>
174 <para>Many packages use the name <command>cc</command> to call the C
175 compiler. To satisfy those packages, create a symlink:</para>
177 <screen><userinput remap="install">ln -sv gcc /usr/bin/cc</userinput></screen>
179 <para>Add a compatibility symlink to enable building programs with
180 Link Time Optimization (LTO):</para>
182 <screen><userinput remap="install">install -v -dm755 /usr/lib/bfd-plugins
183 ln -sfv ../../libexec/gcc/$(gcc -dumpmachine)/&gcc-version;/liblto_plugin.so \
184 /usr/lib/bfd-plugins/</userinput></screen>
186 <para>Now that our final toolchain is in place, it is important to again ensure
187 that compiling and linking will work as expected. We do this by performing
188 the same sanity checks as we did earlier in the chapter:</para>
190 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
192 xpointer="xpointer(//*[@os='a'])"/>
194 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
196 xpointer="xpointer(//*[@os='b'])"/>
198 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
200 xpointer="xpointer(//*[@os='c'])"/>
202 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
204 xpointer="xpointer(//*[@os='d'])"/>
206 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
208 xpointer="xpointer(//*[@os='e'])"/>
210 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
212 xpointer="xpointer(//*[@os='f'])"/>
214 <screen><computeroutput>/usr/lib/gcc/x86_64-pc-linux-gnu/&gcc-version;/../../../../lib/crt1.o succeeded
215 /usr/lib/gcc/x86_64-pc-linux-gnu/&gcc-version;/../../../../lib/crti.o succeeded
216 /usr/lib/gcc/x86_64-pc-linux-gnu/&gcc-version;/../../../../lib/crtn.o succeeded</computeroutput></screen>
218 <para>Depending on your machine architecture, the above may differ slightly,
219 the difference usually being the name of the directory
220 after <filename class="directory">/usr/lib/gcc</filename>. The important
221 thing to look for here is that <command>gcc</command> has found all three
222 <filename>crt*.o</filename> files under the
223 <filename class="directory">/usr/lib</filename> directory.</para>
225 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
227 xpointer="xpointer(//*[@os='g'])"/>
229 <screen><userinput>grep -B4 '^ /usr/include' dummy.log</userinput></screen>
231 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
233 xpointer="xpointer(//*[@os='h'])"/>
235 <screen><computeroutput>#include <...> search starts here:
236 /usr/lib/gcc/x86_64-pc-linux-gnu/&gcc-version;/include
238 /usr/lib/gcc/x86_64-pc-linux-gnu/&gcc-version;/include-fixed
239 /usr/include</computeroutput></screen>
241 <para>Again, note that the directory named after your target triplet may be
242 different than the above, depending on your architecture.</para>
244 <!-- This appears to be obsolete
246 <note><para>As of version 4.3.0, GCC now unconditionally installs the
247 <filename>limits.h</filename> file into the private
248 <filename class="directory">include-fixed</filename> directory, and that
249 directory is required to be in place.</para></note>
252 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
254 xpointer="xpointer(//*[@os='i'])"/>
256 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
258 xpointer="xpointer(//*[@os='j'])"/>
260 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
262 xpointer="xpointer(//*[@os='k'])"/>
264 <screen><computeroutput>SEARCH_DIR("/usr/x86_64-pc-linux-gnu/lib64")
265 SEARCH_DIR("/usr/local/lib64")
267 SEARCH_DIR("/usr/lib64")
268 SEARCH_DIR("/usr/x86_64-pc-linux-gnu/lib")
269 SEARCH_DIR("/usr/local/lib")
271 SEARCH_DIR("/usr/lib");</computeroutput></screen>
273 <para>A 32-bit system may see a few different directories. For example, here
274 is the output from an i686 machine:</para>
276 <screen><computeroutput>SEARCH_DIR("/usr/i686-pc-linux-gnu/lib32")
277 SEARCH_DIR("/usr/local/lib32")
279 SEARCH_DIR("/usr/lib32")
280 SEARCH_DIR("/usr/i686-pc-linux-gnu/lib")
281 SEARCH_DIR("/usr/local/lib")
283 SEARCH_DIR("/usr/lib");</computeroutput></screen>
285 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
287 xpointer="xpointer(//*[@os='l'])"/>
289 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
291 xpointer="xpointer(//*[@os='m'])"/>
293 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
295 xpointer="xpointer(//*[@os='n'])"/>
297 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
299 xpointer="xpointer(//*[@os='o'])"/>
301 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
303 xpointer="xpointer(//*[@os='p'])"/>
305 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
307 xpointer="xpointer(//*[@os='q'])"/>
309 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
311 xpointer="xpointer(//*[@os='r'])"/>
313 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
315 xpointer="xpointer(//*[@os='s'])"/>
317 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
319 xpointer="xpointer(//*[@os='t'])"/>
321 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
323 xpointer="xpointer(//*[@os='u'])"/>
325 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
327 xpointer="xpointer(//*[@os='v'])"/>
329 <para>Finally, move a misplaced file:</para>
331 <screen><userinput remap="install">mkdir -pv /usr/share/gdb/auto-load/usr/lib
332 mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib</userinput></screen>
336 <sect2 id="contents-gcc" role="content">
337 <title>Contents of GCC</title>
340 <segtitle>Installed programs</segtitle>
341 <segtitle>Installed libraries</segtitle>
342 <segtitle>Installed directories</segtitle>
345 <seg>c++, cc (link to gcc), cpp, g++, gcc,
346 gcc-ar, gcc-nm, gcc-ranlib, gcov, gcov-dump, and gcov-tool</seg>
348 <seg>libasan.{a,so}, libatomic.{a,so}, libcc1.so, libgcc.a, libgcc_eh.a,
349 libgcc_s.so, libgcov.a, libgomp.{a,so}, libitm.{a,so},
350 liblsan.{a,so}, liblto_plugin.so,
351 libquadmath.{a,so}, libssp.{a,so}, libssp_nonshared.a,
352 libstdc++.{a,so}, libstdc++fs.a, libsupc++.a, libtsan.{a,so},
353 and libubsan.{a,so}</seg>
355 <seg>/usr/include/c++, /usr/lib/gcc, /usr/libexec/gcc, and
356 /usr/share/gcc-&gcc-version;</seg>
361 <bridgehead renderas="sect3">Short Descriptions</bridgehead>
362 <?dbfo list-presentation="list"?>
363 <?dbhtml list-presentation="table"?>
365 <varlistentry id="c">
366 <term><command>c++</command></term>
368 <para>The C++ compiler</para>
369 <indexterm zone="ch-system-gcc c">
370 <primary sortas="b-c++">c++</primary>
375 <varlistentry id="cc">
376 <term><command>cc</command></term>
378 <para>The C compiler</para>
379 <indexterm zone="ch-system-gcc cc">
380 <primary sortas="b-cc">cc</primary>
385 <varlistentry id="cpp">
386 <term><command>cpp</command></term>
388 <para>The C preprocessor; it is used by the compiler to expand the
389 #include, #define, and similar statements in the source files</para>
390 <indexterm zone="ch-system-gcc cpp">
391 <primary sortas="b-cpp">cpp</primary>
396 <varlistentry id="g">
397 <term><command>g++</command></term>
399 <para>The C++ compiler</para>
400 <indexterm zone="ch-system-gcc g">
401 <primary sortas="b-g++">g++</primary>
406 <varlistentry id="gcc">
407 <term><command>gcc</command></term>
409 <para>The C compiler</para>
410 <indexterm zone="ch-system-gcc gcc">
411 <primary sortas="b-gcc">gcc</primary>
416 <varlistentry id="gcc-ar">
417 <term><command>gcc-ar</command></term>
419 <para>A wrapper around <command>ar</command> that adds a
420 plugin to the command line. This program is only used
421 to add "link time optimization" and is not useful with the
422 default build options</para>
423 <indexterm zone="ch-system-gcc gcc-ar">
424 <primary sortas="b-gcc-ar">gc-ar</primary>
429 <varlistentry id="gcc-nm">
430 <term><command>gcc-nm</command></term>
432 <para>A wrapper around <command>nm</command> that adds a
433 plugin to the command line. This program is only used
434 to add "link time optimization" and is not useful with the
435 default build options</para>
436 <indexterm zone="ch-system-gcc gcc-nm">
437 <primary sortas="b-gcc-nm">gc-nm</primary>
442 <varlistentry id="gcc-ranlib">
443 <term><command>gcc-ranlib</command></term>
445 <para>A wrapper around <command>ranlib</command> that adds a
446 plugin to the command line. This program is only used
447 to add "link time optimization" and is not useful with the
448 default build options</para>
449 <indexterm zone="ch-system-gcc gcc-ranlib">
450 <primary sortas="b-gcc-ranlib">gc-ranlib</primary>
455 <varlistentry id="gcov">
456 <term><command>gcov</command></term>
458 <para>A coverage testing tool; it is used to analyze programs to
459 determine where optimizations will have the most effect</para>
460 <indexterm zone="ch-system-gcc gcov">
461 <primary sortas="b-gcov">gcov</primary>
466 <varlistentry id="gcov-dump">
467 <term><command>gcov-dump</command></term>
469 <para>Offline gcda and gcno profile dump tool</para>
470 <indexterm zone="ch-system-gcc gcov-dump">
471 <primary sortas="b-gcov-dump">gcov-dump</primary>
476 <varlistentry id="gcov-tool">
477 <term><command>gcov-tool</command></term>
479 <para>Offline gcda profile processing tool</para>
480 <indexterm zone="ch-system-gcc gcov-tool">
481 <primary sortas="b-gcov-tool">gcov-tool</primary>
486 <varlistentry id="libasan">
487 <term><filename class="libraryfile">libasan</filename></term>
489 <para>The Address Sanitizer runtime library</para>
490 <indexterm zone="ch-system-gcc libasan">
491 <primary sortas="b-libasan">libasan</primary>
496 <varlistentry id="libatomic">
497 <term><filename class="libraryfile">libatomic</filename></term>
499 <para>GCC atomic built-in runtime library</para>
500 <indexterm zone="ch-system-gcc libatomic">
501 <primary sortas="b-libatomic">libatomic</primary>
506 <varlistentry id="libcc1">
507 <term><filename class="libraryfile">libcc1</filename></term>
509 <para>The C preprocessing library</para>
510 <indexterm zone="ch-system-gcc libcc1">
511 <primary sortas="b-libcc1">libcc1</primary>
516 <varlistentry id="libgcc">
517 <term><filename class="libraryfile">libgcc</filename></term>
519 <para>Contains run-time support for <command>gcc</command></para>
520 <indexterm zone="ch-system-gcc libgcc">
521 <primary sortas="c-libgcc">libgcc</primary>
526 <varlistentry id="libgcov">
527 <term><filename class="libraryfile">libgcov</filename></term>
529 <para>This library is linked in to a program when GCC is instructed
530 to enable profiling</para>
531 <indexterm zone="ch-system-gcc libgcov">
532 <primary sortas="c-libgcov">libgcov</primary>
537 <varlistentry id="libgomp">
538 <term><filename class="libraryfile">libgomp</filename></term>
540 <para>GNU implementation of the OpenMP API for multi-platform
541 shared-memory parallel programming in C/C++ and Fortran</para>
542 <indexterm zone="ch-system-gcc libgomp">
543 <primary sortas="c-libgomp">libgomp</primary>
548 <varlistentry id="liblsan">
549 <term><filename class="libraryfile">liblsan</filename></term>
551 <para>The Leak Sanitizer runtime library</para>
552 <indexterm zone="ch-system-gcc liblsan">
553 <primary sortas="c-liblsan">liblsan</primary>
558 <varlistentry id="liblto_plugin">
559 <term><filename class="libraryfile">liblto_plugin</filename></term>
561 <para>GCC's Link Time Optimization (LTO) plugin allows GCC to perform
562 optimizations across compilation units</para>
563 <indexterm zone="ch-system-gcc liblto_plugin">
564 <primary sortas="c-liblto_plugin">liblto_plugin</primary>
569 <varlistentry id="libquadmath">
570 <term><filename class="libraryfile">libquadmath</filename></term>
572 <para>GCC Quad Precision Math Library API</para>
573 <indexterm zone="ch-system-gcc libquadmath">
574 <primary sortas="c-libquadmath">libquadmath</primary>
579 <varlistentry id="libssp">
580 <term><filename class="libraryfile">libssp</filename></term>
582 <para>Contains routines supporting GCC's stack-smashing protection
584 <indexterm zone="ch-system-gcc libssp">
585 <primary sortas="c-libssp">libssp</primary>
590 <varlistentry id="libstdc">
591 <term><filename class="libraryfile">libstdc++</filename></term>
593 <para>The standard C++ library</para>
594 <indexterm zone="ch-system-gcc libstdc">
595 <primary sortas="c-libstdc++">libstdc++</primary>
600 <varlistentry id="libstdcfs">
601 <term><filename class="libraryfile">libstdc++fs</filename></term>
603 <para>ISO/IEC TS 18822:2015 Filesystem library</para>
604 <indexterm zone="ch-system-gcc libstdcfs">
605 <primary sortas="c-libstdc++fs">libstdc++fs</primary>
610 <varlistentry id="libsupc">
611 <term><filename class="libraryfile">libsupc++</filename></term>
613 <para>Provides supporting routines for the C++ programming
615 <indexterm zone="ch-system-gcc libsupc">
616 <primary sortas="c-libsupc++">libsupc++</primary>
621 <varlistentry id="libtsan">
622 <term><filename class="libraryfile">libtsan</filename></term>
624 <para>The Thread Sanitizer runtime library</para>
625 <indexterm zone="ch-system-gcc libtsan">
626 <primary sortas="c-libtsan">libtsan</primary>
631 <varlistentry id="libubsan">
632 <term><filename class="libraryfile">libubsan</filename></term>
634 <para>The Undefined Behavior Sanitizer runtime library</para>
635 <indexterm zone="ch-system-gcc libubsan">
636 <primary sortas="c-libubsan">libubsan</primary>