source: chapter05/gcc-pass1.xml@ dd30a4b

7.9-systemd 7.9-systemd-rc1 7.9-systemd-rc2 systemd
Last change on this file since dd30a4b was dd30a4b, checked in by DJ Lucas <dj@…>, 6 years ago

Merge from trunk r10991.

git-svn-id: http://svn.linuxfromscratch.org/LFS/branches/systemd@10992 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

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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-tools-gcc-pass1" role="wrap">
9 <?dbhtml filename="gcc-pass1.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 1</title>
18
19 <indexterm zone="ch-tools-gcc-pass1">
20 <primary sortas="a-GCC">GCC</primary>
21 <secondary>tools, pass 1</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-ch5p1-sbu;</seg>
37 <seg>&gcc-ch5p1-du;</seg>
38 </seglistitem>
39 </segmentedlist>
40
41 </sect2>
42
43 <sect2 role="installation">
44 <title>Installation of Cross GCC</title>
45
46 <para>GCC now requires the GMP, MPFR and MPC packages. As these packages may
47 not be included in your host distribution, they will be built with
48 GCC. Unpack each package into the GCC source directory and rename the
49 resulting directories so the GCC build procedures will automatically
50 use them:</para>
51
52 <note><para>There are frequent misunderstandings about this chapter. The
53 procedures are the same as every other chapter as explained earlier (<xref
54 linkend='buildinstr'/>). First extract the gcc tarball from the sources
55 directory and then change to the directory created. Only then should you
56 proceed with the instructions below.</para></note>
57
58<screen><userinput remap="pre">tar -xf ../mpfr-&mpfr-version;.tar.xz
59mv -v mpfr-&mpfr-version; mpfr
60tar -xf ../gmp-&gmp-version;.tar.xz
61mv -v gmp-&gmp-extracted-version; gmp
62tar -xf ../mpc-&mpc-version;.tar.gz
63mv -v mpc-&mpc-version; mpc</userinput></screen>
64
65 <para>The following command will change the location of GCC's default
66 dynamic linker to use the one installed in <filename
67 class="directory">/tools</filename>. It also removes <filename
68 class="directory">/usr/include</filename> from GCC's include search path.
69 Issue:</para>
70
71<screen><userinput remap="pre">for file in \
72 $(find gcc/config -name linux64.h -o -name linux.h -o -name sysv4.h)
73do
74 cp -uv $file{,.orig}
75 sed -e 's@/lib\(64\)\?\(32\)\?/ld@/tools&amp;@g' \
76 -e 's@/usr@/tools@g' $file.orig &gt; $file
77 echo '
78#undef STANDARD_STARTFILE_PREFIX_1
79#undef STANDARD_STARTFILE_PREFIX_2
80#define STANDARD_STARTFILE_PREFIX_1 "/tools/lib/"
81#define STANDARD_STARTFILE_PREFIX_2 ""' &gt;&gt; $file
82 touch $file.orig
83done</userinput></screen>
84
85 <para>In case the above seems hard to follow, let's break it down a bit.
86 First we find all the files under the <filename
87 class="directory">gcc/config</filename> directory that are named either
88 <filename>linux.h</filename>, <filename>linux64.h</filename> or
89 <filename>sysv4.h</filename>. For each file found, we copy it to a file of
90 the same name but with an added suffix of <quote>.orig</quote>. Then the
91 first sed expression prepends <quote>/tools</quote> to every instance of
92 <quote>/lib/ld</quote>, <quote>/lib64/ld</quote> or
93 <quote>/lib32/ld</quote>, while the second one replaces hard-coded
94 instances of <quote>/usr</quote>. Next, we add our define statements which
95 alter the default startfile prefix to the end of the file. Note that the
96 trailing <quote>/</quote> in <quote>/tools/lib/</quote> is required.
97 Finally, we use <command>touch</command> to update the timestamp on the
98 copied files. When used in conjunction with <command>cp -u</command>, this
99 prevents unexpected changes to the original files in case the commands are
100 inadvertently run twice. </para>
101<!--
102 <para>GCC doesn't detect stack protection correctly, which causes problems
103 for the build of Glibc-&glibc-version;, so fix that by issuing the following
104 command:</para>
105
106<screen><userinput remap="pre">sed -i '/k prot/agcc_cv_libc_provides_ssp=yes' gcc/configure</userinput></screen>
107-->
108
109<!--
110 <para>Also fix a problem identified upstream:</para>
111
112<screen><userinput remap="pre">sed -i 's/if \((code.*))\)/if (\1 \&amp;\&amp; \!DEBUG_INSN_P (insn))/' gcc/sched-deps.c</userinput></screen>
113-->
114 <para>The GCC documentation recommends building GCC
115 in a dedicated build directory:</para>
116
117<screen><userinput remap="pre">mkdir -v build
118cd build</userinput></screen>
119
120 <para>Prepare GCC for compilation:</para>
121
122<screen><userinput remap="configure">../configure \
123 --target=$LFS_TGT \
124 --prefix=/tools \
125 --with-glibc-version=2.11 \
126 --with-sysroot=$LFS \
127 --with-newlib \
128 --without-headers \
129 --with-local-prefix=/tools \
130 --with-native-system-header-dir=/tools/include \
131 --disable-nls \
132 --disable-shared \
133 --disable-multilib \
134 --disable-decimal-float \
135 --disable-threads \
136 --disable-libatomic \
137 --disable-libgomp \
138 --disable-libquadmath \
139 --disable-libssp \
140 --disable-libvtv \
141 --disable-libstdcxx \
142 --enable-languages=c,c++</userinput></screen>
143 <variablelist>
144 <title>The meaning of the configure options:</title>
145
146 <varlistentry>
147 <term><parameter>--with-newlib</parameter></term>
148 <listitem>
149 <para>Since a working C library is not yet available, this ensures
150 that the inhibit_libc constant is defined when building libgcc. This prevents
151 the compiling of any code that requires libc support.</para>
152 </listitem>
153 </varlistentry>
154
155 <varlistentry>
156 <term><parameter>--without-headers</parameter></term>
157 <listitem>
158 <para>When creating a complete cross-compiler, GCC requires
159 standard headers compatible with the target system. For our
160 purposes these headers will not be needed. This switch prevents
161 GCC from looking for them.</para>
162 </listitem>
163 </varlistentry>
164
165 <varlistentry>
166 <term><parameter>--with-local-prefix=/tools</parameter></term>
167 <listitem>
168 <para>The local prefix is the location in the system that GCC will search
169 for locally installed include files. The default is <filename>/usr/local</filename>.
170 Setting this to <filename>/tools</filename> helps keep the host location of
171 <filename>/usr/local</filename> out of this GCC's search path.</para>
172 </listitem>
173 </varlistentry>
174
175 <varlistentry>
176 <term><parameter>--with-native-system-header-dir=/tools/include</parameter></term>
177 <listitem>
178 <para>By default GCC searches <filename>/usr/include</filename> for system
179 headers. In conjunction with the sysroot switch, this would translate normally
180 to <filename>$LFS/usr/include</filename>. However the headers that will be installed
181 in the next two sections will go to <filename>$LFS/tools/include</filename>. This
182 switch ensures that gcc will find them correctly. In the second pass of GCC, this
183 same switch will ensure that no headers from the host system are found.</para>
184 </listitem>
185 </varlistentry>
186
187 <varlistentry>
188 <term><parameter>--disable-shared</parameter></term>
189 <listitem>
190 <para>This switch forces GCC to link its internal libraries
191 statically. We do this to avoid possible issues with the host
192 system.</para>
193 </listitem>
194 </varlistentry>
195
196 <varlistentry>
197 <term><parameter>--disable-decimal-float, --disable-threads,
198 --disable-libatomic, --disable-libgomp, --disable-libquadmath,
199 --disable-libssp, --disable-libvtv, --disable-libstdcxx</parameter></term>
200 <listitem>
201 <para>These switches disable support for the decimal floating point
202 extension, threading, libatomic, libgomp, libquadmath, libssp,
203 libvtv, and the C++ standard library respectively. These features
204 will fail to compile when building a cross-compiler and are not
205 necessary for the task of cross-compiling the temporary libc.</para>
206 </listitem>
207 </varlistentry>
208
209 <varlistentry>
210 <term><parameter>--disable-multilib</parameter></term>
211 <listitem>
212 <para>On x86_64, LFS does not yet support a multilib configuration.
213 This switch is harmless for x86.</para>
214 </listitem>
215 </varlistentry>
216
217 <varlistentry>
218 <term><parameter>--enable-languages=c,c++</parameter></term>
219 <listitem>
220 <para>This option ensures that only the C and C++ compilers are built.
221 These are the only languages needed now.</para>
222 </listitem>
223 </varlistentry>
224
225 </variablelist>
226
227 <para>Compile GCC by running:</para>
228
229<screen><userinput remap="make">make</userinput></screen>
230
231 <para>Compilation is now complete. At this point, the test suite would
232 normally be run, but, as mentioned before, the test suite framework is
233 not in place yet. The benefits of running the tests at this point
234 are minimal since the programs from this first pass will soon be
235 replaced.</para>
236
237 <para>Install the package:</para>
238
239<screen><userinput remap="install">make install</userinput></screen>
240<!--
241 <para>Using <parameter>- -disable-shared</parameter> means that the
242 <filename>libgcc_eh.a</filename> file isn't created and installed. The
243 Glibc package depends on this library as it uses
244 <parameter>-lgcc_eh</parameter> within its build system. This dependency
245 can be satisfied by creating a symlink to <filename>libgcc.a</filename>,
246 since that file will end up containing the objects normally contained in
247 <filename>libgcc_eh.a</filename>:</para>
248
249<screen><userinput remap="install">ln -sv libgcc.a `$LFS_TGT-gcc -print-libgcc-file-name | sed 's/libgcc/&amp;_eh/'`</userinput></screen>
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>
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