source: chapter08/gcc.xml@ 100ca4e

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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">
5 %general-entities;
6]>
7
8<sect1 id="ch-system-gcc" role="wrap">
9 <?dbhtml filename="gcc.html"?>
10
11 <sect1info condition="script">
12 <productname>gcc</productname>
13 <productnumber>&gcc-version;</productnumber>
14 <address>&gcc-url;</address>
15 </sect1info>
16
17 <title>GCC-&gcc-version;</title>
18
19 <indexterm zone="ch-system-gcc">
20 <primary sortas="a-GCC">GCC</primary>
21 </indexterm>
22
23 <sect2 role="package">
24 <title/>
25
26 <para>The GCC package contains the GNU compiler collection, which includes
27 the C and C++ compilers.</para>
28
29 <segmentedlist>
30 <segtitle>&buildtime;</segtitle>
31 <segtitle>&diskspace;</segtitle>
32
33 <seglistitem>
34 <seg>&gcc-fin-sbu;</seg>
35 <seg>&gcc-fin-du;</seg>
36 </seglistitem>
37 </segmentedlist>
38
39 </sect2>
40
41 <sect2 role="installation">
42 <title>Installation of GCC</title>
43<!--
44 <para>At first, fix an issue breaking
45 <filename class="libraryfile">libasan.a</filename> building this package
46 with Glibc-2.34 or later:</para>
47
48<screen><userinput remap="pre">sed -e '/static.*SIGSTKSZ/d' \
49 -e 's/return kAltStackSize/return SIGSTKSZ * 4/' \
50 -i libsanitizer/sanitizer_common/sanitizer_posix_libcdep.cpp</userinput></screen>
51-->
52 <para>For x86_64 target, set the default directory name for
53 64-bit libraries to <quote>lib</quote>. The command is unnecessary,
54 but harmless for 32-bit x86. If you are building for another target,
55 you may need to adjust the command for your target.</para>
56
57<screen><userinput remap="pre">sed -e '/m64=/s/lib64/lib/' \
58 -i.orig gcc/config/i386/t-linux64</userinput></screen>
59
60 <para>The GCC documentation recommends building GCC in a dedicated build directory:</para>
61
62<screen><userinput remap="pre">mkdir -v build
63cd build</userinput></screen>
64
65 <para>Prepare GCC for compilation:</para>
66
67<screen><userinput remap="configure">../configure --prefix=/usr \
68 LD=ld \
69 --enable-languages=c,c++ \
70 --disable-multilib \
71 --disable-bootstrap \
72 --with-system-zlib</userinput></screen>
73
74 <para>Note that for other programming languages there are some prerequisites that
75 are not yet available. See the
76 <ulink url="&blfs-book;general/gcc.html">BLFS Book GCC page</ulink>
77 for instructions on how to build all of GCC's supported languages.</para>
78
79 <variablelist>
80 <title>The meaning of the new configure parameters:</title>
81
82 <varlistentry>
83 <term><parameter>LD=ld</parameter></term>
84 <listitem>
85 <para>This parameter makes the configure script use the ld installed
86 by the binutils built earlier in this chapter, rather than
87 the cross-built version which would otherwise be used.</para>
88 </listitem>
89 </varlistentry>
90
91 <varlistentry>
92 <term><parameter>--with-system-zlib</parameter></term>
93 <listitem>
94 <para>This switch tells GCC to link to the system installed copy of
95 the zlib library, rather than its own internal copy.</para>
96 </listitem>
97 </varlistentry>
98 </variablelist>
99
100 <para>Compile the package:</para>
101
102<screen><userinput remap="make">make</userinput></screen>
103
104 <important>
105 <para>In this section, the test suite for GCC is considered
106 important, but it takes a long time. First time builders are
107 encouraged to not skip it. The time to run the tests can be
108 reduced significantly by adding -jx to the make command below
109 where x is the number of cores on your system.</para>
110 </important>
111
112 <para>One set of tests in the GCC test suite is known to exhaust the default
113 stack, so increase the stack size prior to running the tests:</para>
114
115<screen><userinput remap="test">ulimit -s 32768</userinput></screen>
116
117 <para>Test the results as a non-privileged user, but do not stop at errors:</para>
118
119<screen><userinput remap="test">chown -Rv tester .
120su tester -c "PATH=$PATH make -k check"</userinput></screen>
121
122 <para>To receive a summary of the test suite results, run:</para>
123
124<screen><userinput remap="test">../contrib/test_summary</userinput></screen>
125
126 <para>For only the summaries, pipe the output through
127 <userinput>grep -A7 Summ</userinput>.</para>
128
129 <para>Results can be compared with those located at <ulink
130 url="&test-results;"/> and
131 <ulink url="https://gcc.gnu.org/ml/gcc-testresults/"/>.</para>
132
133 <para>In g++, four tests related to PR100400 are known to be reported
134 as both XPASS and FAIL. It's because the test file for this known issue
135 is not well written.</para>
136
137 <para>A few unexpected failures cannot always be avoided. The GCC developers
138 are usually aware of these issues, but have not resolved them yet.
139 Unless the test results are vastly different from those at the above URL,
140 it is safe to continue.</para>
141
142 <!--note><para>
143 On some combinations of kernel configuration and AMD processors
144 there may be more than 1100 failures in the gcc.target/i386/mpx
145 tests (which are designed to test the MPX option on recent
146 Intel processors). These can safely be ignored on AMD
147 processors. These tests will also fail on Intel processors if MPX support
148 is not enabled in the kernel even though it is present on the CPU.
149 </para></note-->
150
151 <para>Install the package:</para>
152
153<screen><userinput remap="install">make install</userinput></screen>
154
155 <para>The GCC build directory is owned by <systemitem class="username">
156 tester</systemitem> now and the ownership of the installed header
157 directory (and its content) will be incorrect. Change the ownership to
158 <systemitem class="username">root</systemitem> user and group:</para>
159
160<screen><userinput remap="install">chown -v -R root:root \
161 /usr/lib/gcc/$(gcc -dumpmachine)/&gcc-version;/include{,-fixed}</userinput></screen>
162
163 <para>Create a symlink required by the <ulink
164 url="https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s09.html">FHS</ulink>
165 for "historical" reasons.</para>
166
167<screen><userinput remap="install">ln -svr /usr/bin/cpp /usr/lib</userinput></screen>
168 <!-- already done earlier
169 <para>Many packages use the name <command>cc</command> to call the C
170 compiler. To satisfy those packages, create a symlink:</para>
171
172<screen><userinput remap="install">ln -sv gcc /usr/bin/cc</userinput></screen>
173 -->
174 <para>Add a compatibility symlink to enable building programs with
175 Link Time Optimization (LTO):</para>
176
177<screen><userinput remap="install">ln -sfv ../../libexec/gcc/$(gcc -dumpmachine)/&gcc-version;/liblto_plugin.so \
178 /usr/lib/bfd-plugins/</userinput></screen>
179
180 <para>Now that our final toolchain is in place, it is important to again ensure
181 that compiling and linking will work as expected. We do this by performing
182 some sanity checks:</para>
183
184<screen><userinput>echo 'int main(){}' &gt; dummy.c
185cc dummy.c -v -Wl,--verbose &amp;&gt; dummy.log
186readelf -l a.out | grep ': /lib'</userinput></screen>
187
188 <para>There should be no errors,
189 and the output of the last command will be (allowing for
190 platform-specific differences in the dynamic linker name):</para>
191
192<screen><computeroutput>[Requesting program interpreter: /lib64/ld-linux-x86-64.so.2]</computeroutput></screen>
193
194 <para>Now make sure that we're setup to use the correct start files:</para>
195
196<screen><userinput>grep -o '/usr/lib.*/crt[1in].*succeeded' dummy.log</userinput></screen>
197
198 <para>The output of the last command should be:</para>
199
200<screen><computeroutput>/usr/lib/gcc/x86_64-pc-linux-gnu/&gcc-version;/../../../../lib/crt1.o succeeded
201/usr/lib/gcc/x86_64-pc-linux-gnu/&gcc-version;/../../../../lib/crti.o succeeded
202/usr/lib/gcc/x86_64-pc-linux-gnu/&gcc-version;/../../../../lib/crtn.o succeeded</computeroutput></screen>
203
204 <para>Depending on your machine architecture, the above may differ slightly.
205 The difference will be the name of the directory
206 after <filename class="directory">/usr/lib/gcc</filename>. The important
207 thing to look for here is that <command>gcc</command> has found all three
208 <filename>crt*.o</filename> files under the
209 <filename class="directory">/usr/lib</filename> directory.</para>
210
211 <para>Verify that the compiler is searching for the correct header
212 files:</para>
213
214<screen><userinput>grep -B4 '^ /usr/include' dummy.log</userinput></screen>
215
216 <para>This command should return the following output:</para>
217
218<screen><computeroutput>#include &lt;...&gt; search starts here:
219 /usr/lib/gcc/x86_64-pc-linux-gnu/&gcc-version;/include
220 /usr/local/include
221 /usr/lib/gcc/x86_64-pc-linux-gnu/&gcc-version;/include-fixed
222 /usr/include</computeroutput></screen>
223
224 <para>Again, the directory named after your target triplet may be
225 different than the above, depending on your system architecture.</para>
226
227 <para>Next, verify that the new linker is being used with the correct search paths:</para>
228
229<screen><userinput>grep 'SEARCH.*/usr/lib' dummy.log |sed 's|; |\n|g'</userinput></screen>
230
231 <para>References to paths that have components with '-linux-gnu' should
232 be ignored, but otherwise the output of the last command should be:</para>
233
234<screen><computeroutput>SEARCH_DIR("/usr/x86_64-pc-linux-gnu/lib64")
235SEARCH_DIR("/usr/local/lib64")
236SEARCH_DIR("/lib64")
237SEARCH_DIR("/usr/lib64")
238SEARCH_DIR("/usr/x86_64-pc-linux-gnu/lib")
239SEARCH_DIR("/usr/local/lib")
240SEARCH_DIR("/lib")
241SEARCH_DIR("/usr/lib");</computeroutput></screen>
242
243 <para>A 32-bit system may see a few different directories. For example, here
244 is the output from an i686 machine:</para>
245
246<screen><computeroutput>SEARCH_DIR("/usr/i686-pc-linux-gnu/lib32")
247SEARCH_DIR("/usr/local/lib32")
248SEARCH_DIR("/lib32")
249SEARCH_DIR("/usr/lib32")
250SEARCH_DIR("/usr/i686-pc-linux-gnu/lib")
251SEARCH_DIR("/usr/local/lib")
252SEARCH_DIR("/lib")
253SEARCH_DIR("/usr/lib");</computeroutput></screen>
254
255 <para>Next make sure that we're using the correct libc:</para>
256
257<screen><userinput>grep "/lib.*/libc.so.6 " dummy.log</userinput></screen>
258
259 <para>The output of the last command should be:</para>
260
261<screen><computeroutput>attempt to open /usr/lib/libc.so.6 succeeded</computeroutput></screen>
262
263 <para>Make sure GCC is using the correct dynamic linker:</para>
264
265<screen><userinput>grep found dummy.log</userinput></screen>
266
267 <para>The output of the last command should be (allowing for
268 platform-specific differences in dynamic linker name):</para>
269
270<screen><computeroutput>found ld-linux-x86-64.so.2 at /usr/lib/ld-linux-x86-64.so.2</computeroutput></screen>
271
272 <para>If the output does not appear as shown above or is not received
273 at all, then something is seriously wrong. Investigate and retrace the
274 steps to find out where the problem is and correct it. <!--The most likely
275 reason is that something went wrong with the specs file adjustment.--> Any
276 issues will need to be resolved before continuing with the process.</para>
277
278 <para>Once everything is working correctly, clean up the test files:</para>
279
280<screen><userinput>rm -v dummy.c a.out dummy.log</userinput></screen>
281
282 <para>Finally, move a misplaced file:</para>
283
284<screen><userinput remap="install">mkdir -pv /usr/share/gdb/auto-load/usr/lib
285mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib</userinput></screen>
286
287 </sect2>
288
289 <sect2 id="contents-gcc" role="content">
290 <title>Contents of GCC</title>
291
292 <segmentedlist>
293 <segtitle>Installed programs</segtitle>
294 <segtitle>Installed libraries</segtitle>
295 <segtitle>Installed directories</segtitle>
296
297 <seglistitem>
298 <seg>c++, cc (link to gcc), cpp, g++, gcc,
299 gcc-ar, gcc-nm, gcc-ranlib, gcov, gcov-dump, gcov-tool,
300 and lto-dump</seg>
301
302 <seg>libasan.{a,so}, libatomic.{a,so}, libcc1.so, libgcc.a, libgcc_eh.a,
303 libgcc_s.so, libgcov.a, libgomp.{a,so}, libitm.{a,so},
304 liblsan.{a,so}, liblto_plugin.so,
305 libquadmath.{a,so}, libssp.{a,so}, libssp_nonshared.a,
306 libstdc++.{a,so}, libstdc++fs.a, libsupc++.a, libtsan.{a,so},
307 and libubsan.{a,so}</seg>
308
309 <seg>/usr/include/c++, /usr/lib/gcc, /usr/libexec/gcc, and
310 /usr/share/gcc-&gcc-version;</seg>
311 </seglistitem>
312 </segmentedlist>
313
314 <variablelist>
315 <bridgehead renderas="sect3">Short Descriptions</bridgehead>
316 <?dbfo list-presentation="list"?>
317 <?dbhtml list-presentation="table"?>
318
319 <varlistentry id="c">
320 <term><command>c++</command></term>
321 <listitem>
322 <para>The C++ compiler</para>
323 <indexterm zone="ch-system-gcc c">
324 <primary sortas="b-c++">c++</primary>
325 </indexterm>
326 </listitem>
327 </varlistentry>
328
329 <varlistentry id="cc">
330 <term><command>cc</command></term>
331 <listitem>
332 <para>The C compiler</para>
333 <indexterm zone="ch-system-gcc cc">
334 <primary sortas="b-cc">cc</primary>
335 </indexterm>
336 </listitem>
337 </varlistentry>
338
339 <varlistentry id="cpp">
340 <term><command>cpp</command></term>
341 <listitem>
342 <para>The C preprocessor; it is used by the compiler to expand the
343 #include, #define, and similar statements in the source files</para>
344 <indexterm zone="ch-system-gcc cpp">
345 <primary sortas="b-cpp">cpp</primary>
346 </indexterm>
347 </listitem>
348 </varlistentry>
349
350 <varlistentry id="g">
351 <term><command>g++</command></term>
352 <listitem>
353 <para>The C++ compiler</para>
354 <indexterm zone="ch-system-gcc g">
355 <primary sortas="b-g++">g++</primary>
356 </indexterm>
357 </listitem>
358 </varlistentry>
359
360 <varlistentry id="gcc">
361 <term><command>gcc</command></term>
362 <listitem>
363 <para>The C compiler</para>
364 <indexterm zone="ch-system-gcc gcc">
365 <primary sortas="b-gcc">gcc</primary>
366 </indexterm>
367 </listitem>
368 </varlistentry>
369
370 <varlistentry id="gcc-ar">
371 <term><command>gcc-ar</command></term>
372 <listitem>
373 <para>A wrapper around <command>ar</command> that adds a
374 plugin to the command line. This program is only used
375 to add "link time optimization" and is not useful with the
376 default build options</para>
377 <indexterm zone="ch-system-gcc gcc-ar">
378 <primary sortas="b-gcc-ar">gc-ar</primary>
379 </indexterm>
380 </listitem>
381 </varlistentry>
382
383 <varlistentry id="gcc-nm">
384 <term><command>gcc-nm</command></term>
385 <listitem>
386 <para>A wrapper around <command>nm</command> that adds a
387 plugin to the command line. This program is only used
388 to add "link time optimization" and is not useful with the
389 default build options</para>
390 <indexterm zone="ch-system-gcc gcc-nm">
391 <primary sortas="b-gcc-nm">gc-nm</primary>
392 </indexterm>
393 </listitem>
394 </varlistentry>
395
396 <varlistentry id="gcc-ranlib">
397 <term><command>gcc-ranlib</command></term>
398 <listitem>
399 <para>A wrapper around <command>ranlib</command> that adds a
400 plugin to the command line. This program is only used
401 to add "link time optimization" and is not useful with the
402 default build options</para>
403 <indexterm zone="ch-system-gcc gcc-ranlib">
404 <primary sortas="b-gcc-ranlib">gc-ranlib</primary>
405 </indexterm>
406 </listitem>
407 </varlistentry>
408
409 <varlistentry id="gcov">
410 <term><command>gcov</command></term>
411 <listitem>
412 <para>A coverage testing tool; it is used to analyze programs to
413 determine where optimizations will have the most effect</para>
414 <indexterm zone="ch-system-gcc gcov">
415 <primary sortas="b-gcov">gcov</primary>
416 </indexterm>
417 </listitem>
418 </varlistentry>
419
420 <varlistentry id="gcov-dump">
421 <term><command>gcov-dump</command></term>
422 <listitem>
423 <para>Offline gcda and gcno profile dump tool</para>
424 <indexterm zone="ch-system-gcc gcov-dump">
425 <primary sortas="b-gcov-dump">gcov-dump</primary>
426 </indexterm>
427 </listitem>
428 </varlistentry>
429
430 <varlistentry id="gcov-tool">
431 <term><command>gcov-tool</command></term>
432 <listitem>
433 <para>Offline gcda profile processing tool</para>
434 <indexterm zone="ch-system-gcc gcov-tool">
435 <primary sortas="b-gcov-tool">gcov-tool</primary>
436 </indexterm>
437 </listitem>
438 </varlistentry>
439
440 <varlistentry id="lto-dump">
441 <term><command>lto-dump</command></term>
442 <listitem>
443 <para>Tool for dumping object files produced by GCC with LTO
444 enabled</para>
445 <indexterm zone="ch-system-gcc lto-dump">
446 <primary sortas="b-lto-dump">lto-dump</primary>
447 </indexterm>
448 </listitem>
449 </varlistentry>
450
451 <varlistentry id="libasan">
452 <term><filename class="libraryfile">libasan</filename></term>
453 <listitem>
454 <para>The Address Sanitizer runtime library</para>
455 <indexterm zone="ch-system-gcc libasan">
456 <primary sortas="b-libasan">libasan</primary>
457 </indexterm>
458 </listitem>
459 </varlistentry>
460
461 <varlistentry id="libatomic">
462 <term><filename class="libraryfile">libatomic</filename></term>
463 <listitem>
464 <para>GCC atomic built-in runtime library</para>
465 <indexterm zone="ch-system-gcc libatomic">
466 <primary sortas="b-libatomic">libatomic</primary>
467 </indexterm>
468 </listitem>
469 </varlistentry>
470
471 <varlistentry id="libcc1">
472 <term><filename class="libraryfile">libcc1</filename></term>
473 <listitem>
474 <para>The C preprocessing library</para>
475 <indexterm zone="ch-system-gcc libcc1">
476 <primary sortas="b-libcc1">libcc1</primary>
477 </indexterm>
478 </listitem>
479 </varlistentry>
480
481 <varlistentry id="libgcc">
482 <term><filename class="libraryfile">libgcc</filename></term>
483 <listitem>
484 <para>Contains run-time support for <command>gcc</command></para>
485 <indexterm zone="ch-system-gcc libgcc">
486 <primary sortas="c-libgcc">libgcc</primary>
487 </indexterm>
488 </listitem>
489 </varlistentry>
490
491 <varlistentry id="libgcov">
492 <term><filename class="libraryfile">libgcov</filename></term>
493 <listitem>
494 <para>This library is linked in to a program when GCC is instructed
495 to enable profiling</para>
496 <indexterm zone="ch-system-gcc libgcov">
497 <primary sortas="c-libgcov">libgcov</primary>
498 </indexterm>
499 </listitem>
500 </varlistentry>
501
502 <varlistentry id="libgomp">
503 <term><filename class="libraryfile">libgomp</filename></term>
504 <listitem>
505 <para>GNU implementation of the OpenMP API for multi-platform
506 shared-memory parallel programming in C/C++ and Fortran</para>
507 <indexterm zone="ch-system-gcc libgomp">
508 <primary sortas="c-libgomp">libgomp</primary>
509 </indexterm>
510 </listitem>
511 </varlistentry>
512
513 <varlistentry id="libitm">
514 <term><filename class="libraryfile">libitm</filename></term>
515 <listitem>
516 <para>The GNU transactional memory library</para>
517 <indexterm zone="ch-system-gcc libitm">
518 <primary sortas="c-libitm">libitm</primary>
519 </indexterm>
520 </listitem>
521 </varlistentry>
522
523 <varlistentry id="liblsan">
524 <term><filename class="libraryfile">liblsan</filename></term>
525 <listitem>
526 <para>The Leak Sanitizer runtime library</para>
527 <indexterm zone="ch-system-gcc liblsan">
528 <primary sortas="c-liblsan">liblsan</primary>
529 </indexterm>
530 </listitem>
531 </varlistentry>
532
533 <varlistentry id="liblto_plugin">
534 <term><filename class="libraryfile">liblto_plugin</filename></term>
535 <listitem>
536 <para>GCC's LTO plugin allows binutils to process object files
537 produced by GCC with LTO enabled</para>
538 <indexterm zone="ch-system-gcc liblto_plugin">
539 <primary sortas="c-liblto_plugin">liblto_plugin</primary>
540 </indexterm>
541 </listitem>
542 </varlistentry>
543
544 <varlistentry id="libquadmath">
545 <term><filename class="libraryfile">libquadmath</filename></term>
546 <listitem>
547 <para>GCC Quad Precision Math Library API</para>
548 <indexterm zone="ch-system-gcc libquadmath">
549 <primary sortas="c-libquadmath">libquadmath</primary>
550 </indexterm>
551 </listitem>
552 </varlistentry>
553
554 <varlistentry id="libssp">
555 <term><filename class="libraryfile">libssp</filename></term>
556 <listitem>
557 <para>Contains routines supporting GCC's stack-smashing protection
558 functionality</para>
559 <indexterm zone="ch-system-gcc libssp">
560 <primary sortas="c-libssp">libssp</primary>
561 </indexterm>
562 </listitem>
563 </varlistentry>
564
565 <varlistentry id="libstdc">
566 <term><filename class="libraryfile">libstdc++</filename></term>
567 <listitem>
568 <para>The standard C++ library</para>
569 <indexterm zone="ch-system-gcc libstdc">
570 <primary sortas="c-libstdc++">libstdc++</primary>
571 </indexterm>
572 </listitem>
573 </varlistentry>
574
575 <varlistentry id="libstdcfs">
576 <term><filename class="libraryfile">libstdc++fs</filename></term>
577 <listitem>
578 <para>ISO/IEC TS 18822:2015 Filesystem library</para>
579 <indexterm zone="ch-system-gcc libstdcfs">
580 <primary sortas="c-libstdc++fs">libstdc++fs</primary>
581 </indexterm>
582 </listitem>
583 </varlistentry>
584
585 <varlistentry id="libsupc">
586 <term><filename class="libraryfile">libsupc++</filename></term>
587 <listitem>
588 <para>Provides supporting routines for the C++ programming
589 language</para>
590 <indexterm zone="ch-system-gcc libsupc">
591 <primary sortas="c-libsupc++">libsupc++</primary>
592 </indexterm>
593 </listitem>
594 </varlistentry>
595
596 <varlistentry id="libtsan">
597 <term><filename class="libraryfile">libtsan</filename></term>
598 <listitem>
599 <para>The Thread Sanitizer runtime library</para>
600 <indexterm zone="ch-system-gcc libtsan">
601 <primary sortas="c-libtsan">libtsan</primary>
602 </indexterm>
603 </listitem>
604 </varlistentry>
605
606 <varlistentry id="libubsan">
607 <term><filename class="libraryfile">libubsan</filename></term>
608 <listitem>
609 <para>The Undefined Behavior Sanitizer runtime library</para>
610 <indexterm zone="ch-system-gcc libubsan">
611 <primary sortas="c-libubsan">libubsan</primary>
612 </indexterm>
613 </listitem>
614 </varlistentry>
615
616 </variablelist>
617
618 </sect2>
619
620</sect1>
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