source: chapter05/gcc-pass2.xml@ 8aa7fde

10.0 10.0-rc1 10.1 10.1-rc1 11.0 11.0-rc1 11.0-rc2 11.0-rc3 7.10 7.10-rc1 7.6 7.6-rc1 7.7 7.7-rc1 7.8 7.8-rc1 7.9 7.9-rc1 7.9-rc2 8.0 8.0-rc1 8.1 8.1-rc1 8.1-rc2 8.2 8.2-rc1 8.3 8.3-rc1 8.3-rc2 8.4 8.4-rc1 9.0 9.0-rc1 9.1 9.1-rc1 BOOK.old cross-chap5 ml-11.0 multilib nosym old-trunk trunk xry111/git-transition xry111/glibc-2.34 xry111/tester-nohack xry111/usr-move
Last change on this file since 8aa7fde was 8aa7fde, checked in by Bruce Dubbs <bdubbs@…>, 8 years ago

Remove unneeded confiugure switches from gcc.
Restore installation of udev-lfs support files.

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@10567 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

  • Property mode set to 100644
File size: 10.4 KB
Line 
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-tools-gcc-pass2" role="wrap">
9 <?dbhtml filename="gcc-pass2.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; - Pass 2</title>
18
19 <indexterm zone="ch-tools-gcc-pass2">
20 <primary sortas="a-GCC">GCC</primary>
21 <secondary>tools, pass 2</secondary>
22 </indexterm>
23
24 <sect2 role="package">
25 <title/>
26
27 <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
28 href="../chapter06/gcc.xml"
29 xpointer="xpointer(/sect1/sect2[1]/para[1])"/>
30
31 <segmentedlist>
32 <segtitle>&buildtime;</segtitle>
33 <segtitle>&diskspace;</segtitle>
34
35 <seglistitem>
36 <seg>&gcc-ch5p2-sbu;</seg>
37 <seg>&gcc-ch5p2-du;</seg>
38 </seglistitem>
39 </segmentedlist>
40
41 </sect2>
42
43 <sect2 role="installation">
44 <title>Installation of GCC</title>
45
46 <para>Our first build of GCC has installed a couple of internal system
47 headers. Normally one of them, <filename>limits.h</filename> will in turn
48 include the corresponding system <filename>limits.h</filename> header, in
49 this case, <filename>/tools/include/limits.h</filename>. However, at the
50 time of the first build of gcc <filename>/tools/include/limits.h</filename>
51 did not exist, so the internal header that GCC installed is a partial,
52 self-contained file and does not include the extended features of the
53 system header. This was adequate for building the temporary libc, but this
54 build of GCC now requires the full internal header. Create a full version
55 of the internal header using a command that is identical to what the GCC
56 build system does in normal circumstances:</para>
57
58<screen><userinput remap="pre">cat gcc/limitx.h gcc/glimits.h gcc/limity.h &gt; \
59 `dirname $($LFS_TGT-gcc -print-libgcc-file-name)`/include-fixed/limits.h</userinput></screen>
60<!--
61 <para>For x86 machines, the limited number of registers is a bottleneck
62 for the system. Free one up by not using a frame pointer that is not
63 needed:</para>
64
65<screen><userinput remap="pre">case `uname -m` in
66 i?86) sed -i 's/^T_CFLAGS =$/&amp; -fomit-frame-pointer/' gcc/Makefile.in ;;
67esac</userinput></screen>
68-->
69 <para>Once again, change the location of GCC's default dynamic linker to
70 use the one installed in <filename
71 class="directory">/tools</filename>.</para>
72
73<screen><userinput remap="pre">for file in \
74 $(find gcc/config -name linux64.h -o -name linux.h -o -name sysv4.h)
75do
76 cp -uv $file{,.orig}
77 sed -e 's@/lib\(64\)\?\(32\)\?/ld@/tools&amp;@g' \
78 -e 's@/usr@/tools@g' $file.orig &gt; $file
79 echo '
80#undef STANDARD_STARTFILE_PREFIX_1
81#undef STANDARD_STARTFILE_PREFIX_2
82#define STANDARD_STARTFILE_PREFIX_1 "/tools/lib/"
83#define STANDARD_STARTFILE_PREFIX_2 ""' &gt;&gt; $file
84 touch $file.orig
85done</userinput></screen>
86
87 <para>As in the first build of GCC it requires the GMP, MPFR and MPC
88 packages. Unpack the tarballs and move them into the required directory
89 names:</para>
90
91<screen><userinput remap="pre">tar -xf ../mpfr-&mpfr-version;.tar.xz
92mv -v mpfr-&mpfr-version; mpfr
93tar -xf ../gmp-&gmp-version;.tar.xz
94mv -v gmp-&gmp-extracted-version; gmp
95tar -xf ../mpc-&mpc-version;.tar.gz
96mv -v mpc-&mpc-version; mpc</userinput></screen>
97
98 <para>Create a separate build directory again:</para>
99
100<screen><userinput remap="pre">mkdir -v ../gcc-build
101cd ../gcc-build</userinput></screen>
102
103 <para>Before starting to build GCC, remember to unset any environment
104 variables that override the default optimization flags.</para>
105
106 <para>Now prepare GCC for compilation:</para>
107
108<screen><userinput remap="configure">CC=$LFS_TGT-gcc \
109CXX=$LFS_TGT-g++ \
110AR=$LFS_TGT-ar \
111RANLIB=$LFS_TGT-ranlib \
112../gcc-&gcc-version;/configure \
113 --prefix=/tools \
114 --with-local-prefix=/tools \
115 --with-native-system-header-dir=/tools/include \
116 --enable-clocale=gnu \
117 --enable-shared \
118 --enable-threads=posix \
119 --enable-__cxa_atexit \
120 --enable-languages=c,c++ \
121 --disable-libstdcxx-pch \
122 --disable-multilib \
123 --disable-bootstrap \
124 --disable-libgomp</userinput></screen>
125
126 <variablelist>
127 <title>The meaning of the new configure options:</title>
128
129 <varlistentry>
130 <term><parameter>--enable-clocale=gnu</parameter></term>
131 <listitem>
132 <para>This option ensures the correct locale model is selected
133 for the C++ libraries under all circumstances. If the configure
134 script finds the <emphasis>de_DE</emphasis> locale installed,
135 it will select the correct gnu locale model. However, if the
136 <emphasis>de_DE</emphasis> locale is not installed, there is the
137 risk of building Application Binary Interface (ABI)-incompatible
138 C++ libraries because the incorrect generic locale model may be
139 selected.</para>
140 </listitem>
141 </varlistentry>
142
143 <varlistentry>
144 <term><parameter>--enable-threads=posix</parameter></term>
145 <listitem>
146 <para>This enables C++ exception handling for multi-threaded code.</para>
147 </listitem>
148 </varlistentry>
149
150 <varlistentry>
151 <term><parameter>--enable-__cxa_atexit</parameter></term>
152 <listitem>
153 <para>This option allows use of <function>__cxa_atexit</function>,
154 rather than <function>atexit</function>, to register C++ destructors
155 for local statics and global objects. This option is essential for
156 fully standards-compliant handling of destructors. It also affects
157 the C++ ABI, and therefore results in C++ shared libraries and C++
158 programs that are interoperable with other Linux distributions.</para>
159 </listitem>
160 </varlistentry>
161
162 <varlistentry>
163 <term><parameter>--enable-languages=c,c++</parameter></term>
164 <listitem>
165 <para>This option ensures that both the C and C++ compilers are
166 built.</para>
167 </listitem>
168 </varlistentry>
169
170 <varlistentry>
171 <term><parameter>--disable-libstdcxx-pch</parameter></term>
172 <listitem>
173 <para>Do not build the pre-compiled header (PCH) for
174 <filename class="libraryfile">libstdc++</filename>. It takes up a
175 lot of space, and we have no use for it.</para>
176 </listitem>
177 </varlistentry>
178
179 <varlistentry>
180 <term><parameter>--disable-bootstrap</parameter></term>
181 <listitem>
182 <para>For native builds of GCC, the default is to do a "bootstrap"
183 build. This does not just compile GCC, but compiles it several times.
184 It uses the programs compiled in a first round to compile itself a
185 second time, and then again a third time. The second and third
186 iterations are compared to make sure it can reproduce itself
187 flawlessly. This also implies that it was compiled correctly.
188 However, the LFS build method should provide a solid compiler
189 without the need to bootstrap each time.</para>
190 </listitem>
191 </varlistentry>
192
193 </variablelist>
194
195 <para>Compile the package:</para>
196
197<screen><userinput remap="make">make</userinput></screen>
198
199 <para>Install the package:</para>
200
201<screen><userinput remap="install">make install</userinput></screen>
202
203 <para>As a finishing touch, create a symlink. Many programs and scripts
204 run <command>cc</command> instead of <command>gcc</command>, which is
205 used to keep programs generic and therefore usable on all kinds of UNIX
206 systems where the GNU C compiler is not always installed. Running
207 <command>cc</command> leaves the system administrator free to decide
208 which C compiler to install:</para>
209
210<screen><userinput remap="install">ln -sv gcc /tools/bin/cc</userinput></screen>
211
212 <caution>
213 <para>At this point, it is imperative to stop and ensure that the basic
214 functions (compiling and linking) of the new toolchain are working as
215 expected. To perform a sanity check, run the following commands:</para>
216
217<screen><userinput>echo 'main(){}' &gt; dummy.c
218cc dummy.c
219readelf -l a.out | grep ': /tools'</userinput></screen>
220
221 <para>If everything is working correctly, there should be no errors,
222 and the output of the last command will be of the form:</para>
223
224<screen><computeroutput>[Requesting program interpreter: /tools/lib/ld-linux.so.2]</computeroutput></screen>
225
226 <para>Note that <filename class="directory">/tools/lib</filename>, or
227 <filename class="directory">/tools/lib64</filename> for 64-bit machines
228 appears as the prefix of the dynamic linker.</para>
229
230 <para>If the output is not shown as above or there was no output at all,
231 then something is wrong. Investigate and retrace the steps to find out
232 where the problem is and correct it. This issue must be resolved before
233 continuing on. First, perform the sanity check again, using
234 <command>gcc</command> instead of <command>cc</command>. If this works,
235 then the <filename class="symlink">/tools/bin/cc</filename> symlink is
236 missing. Install the symlink as per above.
237 Next, ensure that the <envar>PATH</envar> is correct. This
238 can be checked by running <command>echo $PATH</command> and verifying that
239 <filename class="directory">/tools/bin</filename> is at the head of the
240 list. If the <envar>PATH</envar> is wrong it could mean that you are not
241 logged in as user <systemitem class="username">lfs</systemitem> or that
242 something went wrong back in <xref linkend="ch-tools-settingenviron"
243 role="."/></para>
244
245 <para>Once all is well, clean up the test files:</para>
246
247<screen><userinput>rm -v dummy.c a.out</userinput></screen>
248
249 </caution>
250
251 </sect2>
252
253 <sect2 role="content">
254 <title/>
255
256 <para>Details on this package are located in
257 <xref linkend="contents-gcc" role="."/></para>
258
259 </sect2>
260
261</sect1>
Note: See TracBrowser for help on using the repository browser.