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/2003/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>Re-installation of GCC</title>
|
---|
45 |
|
---|
46 | <para>The tools required to test GCC and Binutils—Tcl, Expect
|
---|
47 | and DejaGNU—are installed now. GCC and Binutils can now be
|
---|
48 | rebuilt, linking them against the new Glibc and testing them properly
|
---|
49 | (if running the test suites in this chapter). Please note that these
|
---|
50 | test suites are highly dependent on properly functioning PTYs which
|
---|
51 | are provided by the host. PTYs are most commonly implemented via the
|
---|
52 | <systemitem class="filesystem">devpts</systemitem> file system. Check
|
---|
53 | to see if the host system is set up correctly in this regard by
|
---|
54 | performing a quick test:</para>
|
---|
55 |
|
---|
56 | <screen><userinput remap="test">expect -c "spawn ls"</userinput></screen>
|
---|
57 |
|
---|
58 | <para>The response might be:</para>
|
---|
59 |
|
---|
60 | <screen><computeroutput>The system has no more ptys.
|
---|
61 | Ask your system administrator to create more.</computeroutput></screen>
|
---|
62 |
|
---|
63 | <para>If the above message is received, the host does not have its PTYs
|
---|
64 | set up properly. In this case, there is no point in running the test
|
---|
65 | suites for GCC and Binutils until this issue is resolved. Please consult
|
---|
66 | the LFS FAQ at <ulink url="&lfs-root;/lfs/faq.html#no-ptys"/> for more
|
---|
67 | information on how to get PTYs working.</para>
|
---|
68 |
|
---|
69 | <para>As previously explained in <xref linkend="ch-tools-adjusting"/>,
|
---|
70 | under normal circumstances the GCC <command>fixincludes</command> script
|
---|
71 | is run in order to fix potentially broken header files. As GCC-&gcc-version;
|
---|
72 | and Glibc-&glibc-version; have already been installed at this point, and
|
---|
73 | their respective header files are known to not require fixing, the
|
---|
74 | <command>fixincludes</command> script is not required. As mentioned
|
---|
75 | previously, the script may in fact pollute the build environment by
|
---|
76 | installing fixed headers from the host system into GCC's private include
|
---|
77 | directory. The running of the <command>fixincludes</command> script can
|
---|
78 | be suppressed by issuing the following commands:</para>
|
---|
79 |
|
---|
80 | <screen><userinput remap="pre">cp -v gcc/Makefile.in{,.orig}
|
---|
81 | sed 's@\./fixinc\.sh@-c true@' gcc/Makefile.in.orig > gcc/Makefile.in</userinput></screen>
|
---|
82 |
|
---|
83 | <para>The bootstrap build performed in <xref linkend="ch-tools-gcc-pass1"/>
|
---|
84 | built GCC with the <option>-fomit-frame-pointer</option> compiler flag.
|
---|
85 | Non-bootstrap builds omit this flag by default, so apply the following
|
---|
86 | <command>sed</command> to use it in order to ensure consistent compiler
|
---|
87 | builds:</para>
|
---|
88 |
|
---|
89 | <screen><userinput remap="pre">cp -v gcc/Makefile.in{,.tmp}
|
---|
90 | sed 's/^XCFLAGS =$/& -fomit-frame-pointer/' gcc/Makefile.in.tmp \
|
---|
91 | > gcc/Makefile.in</userinput></screen>
|
---|
92 |
|
---|
93 | <para>The following command will change the location of GCC's default
|
---|
94 | dynamic linker to use the one we installed in
|
---|
95 | <filename class="directory">/tools</filename>. It also removes <filename
|
---|
96 | class="directory">/usr/include</filename> from GCC's include search path.
|
---|
97 | Doing this now rather than adjusting the specs file after installation
|
---|
98 | ensures that the new dynamic linker is used during the actual build of
|
---|
99 | GCC. That is, all of the binaries created during the build will link
|
---|
100 | against the new Glibc. Issue:</para>
|
---|
101 |
|
---|
102 | <screen><userinput remap="pre">for file in $(find gcc/config -name linux64.h -o -name linux.h)
|
---|
103 | do
|
---|
104 | cp -uv $file{,.orig}
|
---|
105 | sed -e 's@/lib\(64\)\?\(32\)\?/ld@/tools&@g' \
|
---|
106 | -e 's@/usr@/tools@g' $file.orig > $file
|
---|
107 | echo "
|
---|
108 | #undef STANDARD_INCLUDE_DIR
|
---|
109 | #define STANDARD_INCLUDE_DIR 0" >> $file
|
---|
110 | touch $file.orig
|
---|
111 | done</userinput></screen>
|
---|
112 |
|
---|
113 | <para>In case the above seems hard to follow, let's break it down a bit.
|
---|
114 | First we find all the files under the gcc/config directory that are named
|
---|
115 | either <filename>linux.h</filename> or <filename>linux64.h</filename>.
|
---|
116 | For each file found, we copy it to a file of the same name but with an added
|
---|
117 | suffix of <quote>.orig</quote>. Then the first sed expression prepends
|
---|
118 | <quote>/tools</quote> to every instance of <quote>/lib/ld</quote>,
|
---|
119 | <quote>/lib64/ld</quote> or <quote>/lib32/ld</quote>, while the second one
|
---|
120 | replaces hard-coded instances of <quote>/usr</quote>. Then we add our define
|
---|
121 | statements which alter the include search path to the end of the file. Finally,
|
---|
122 | we use <command>touch</command> to update the timestamp on the copied files.
|
---|
123 | When used in conjunction with <command>cp -u</command>, this prevents unexpected
|
---|
124 | changes to the original files in case the command is inadvertently run twice.
|
---|
125 | </para>
|
---|
126 |
|
---|
127 | <para>Create a separate build directory again:</para>
|
---|
128 |
|
---|
129 | <screen><userinput remap="pre">mkdir -v ../gcc-build
|
---|
130 | cd ../gcc-build</userinput></screen>
|
---|
131 |
|
---|
132 | <para>Before starting to build GCC, remember to unset any environment
|
---|
133 | variables that override the default optimization flags.</para>
|
---|
134 |
|
---|
135 | <para>Now prepare GCC for compilation:</para>
|
---|
136 |
|
---|
137 | <screen><userinput remap="configure">../gcc-&gcc-version;/configure --prefix=/tools \
|
---|
138 | --with-local-prefix=/tools --enable-clocale=gnu \
|
---|
139 | --enable-shared --enable-threads=posix \
|
---|
140 | --enable-__cxa_atexit --enable-languages=c,c++ \
|
---|
141 | --disable-libstdcxx-pch --disable-bootstrap</userinput></screen>
|
---|
142 |
|
---|
143 | <variablelist>
|
---|
144 | <title>The meaning of the new configure options:</title>
|
---|
145 |
|
---|
146 | <varlistentry>
|
---|
147 | <term><parameter>--enable-clocale=gnu</parameter></term>
|
---|
148 | <listitem>
|
---|
149 | <para>This option ensures the correct locale model is selected
|
---|
150 | for the C++ libraries under all circumstances. If the configure
|
---|
151 | script finds the <emphasis>de_DE</emphasis> locale installed,
|
---|
152 | it will select the correct gnu locale model. However, if the
|
---|
153 | <emphasis>de_DE</emphasis> locale is not installed, there is the
|
---|
154 | risk of building Application Binary Interface (ABI)-incompatible
|
---|
155 | C++ libraries because the incorrect generic locale model may be
|
---|
156 | selected.</para>
|
---|
157 | </listitem>
|
---|
158 | </varlistentry>
|
---|
159 |
|
---|
160 | <varlistentry>
|
---|
161 | <term><parameter>--enable-threads=posix</parameter></term>
|
---|
162 | <listitem>
|
---|
163 | <para>This enables C++ exception handling for multi-threaded code.</para>
|
---|
164 | </listitem>
|
---|
165 | </varlistentry>
|
---|
166 |
|
---|
167 | <varlistentry>
|
---|
168 | <term><parameter>--enable-__cxa_atexit</parameter></term>
|
---|
169 | <listitem>
|
---|
170 | <para>This option allows use of <function>__cxa_atexit</function>,
|
---|
171 | rather than <function>atexit</function>, to register C++ destructors
|
---|
172 | for local statics and global objects. This option is essential for
|
---|
173 | fully standards-compliant handling of destructors. It also affects
|
---|
174 | the C++ ABI, and therefore results in C++ shared libraries and C++
|
---|
175 | programs that are interoperable with other Linux distributions.</para>
|
---|
176 | </listitem>
|
---|
177 | </varlistentry>
|
---|
178 |
|
---|
179 | <varlistentry>
|
---|
180 | <term><parameter>--enable-languages=c,c++</parameter></term>
|
---|
181 | <listitem>
|
---|
182 | <para>This option ensures that both the C and C++ compilers are
|
---|
183 | built.</para>
|
---|
184 | </listitem>
|
---|
185 | </varlistentry>
|
---|
186 |
|
---|
187 | <varlistentry>
|
---|
188 | <term><parameter>--disable-libstdcxx-pch</parameter></term>
|
---|
189 | <listitem>
|
---|
190 | <para>Do not build the pre-compiled header (PCH) for
|
---|
191 | <filename class="libraryfile">libstdc++</filename>. It takes up a
|
---|
192 | lot of space, and we have no use for it.</para>
|
---|
193 | </listitem>
|
---|
194 | </varlistentry>
|
---|
195 |
|
---|
196 | <varlistentry>
|
---|
197 | <term><parameter>--disable-bootstrap</parameter></term>
|
---|
198 | <listitem>
|
---|
199 | <para>Bootstrapping the compiler is now the default for GCC. However,
|
---|
200 | our build method should provide us with a solid compiler without the
|
---|
201 | need to bootstrap each time.</para>
|
---|
202 | </listitem>
|
---|
203 | </varlistentry>
|
---|
204 |
|
---|
205 | </variablelist>
|
---|
206 |
|
---|
207 | <para>Compile the package:</para>
|
---|
208 |
|
---|
209 | <screen><userinput remap="make">make</userinput></screen>
|
---|
210 |
|
---|
211 | <para>There is no need to use the <parameter>bootstrap</parameter> target
|
---|
212 | now because the compiler being used to compile this GCC was built from
|
---|
213 | the exact same version of the GCC sources used earlier.</para>
|
---|
214 |
|
---|
215 | <para>Compilation is now complete. As previously mentioned, running the test
|
---|
216 | suites for the temporary tools compiled in this chapter is not mandatory.
|
---|
217 | To run the GCC test suite anyway, use the following command:</para>
|
---|
218 |
|
---|
219 | <screen><userinput remap="test">make -k check</userinput></screen>
|
---|
220 |
|
---|
221 | <para>The <parameter>-k</parameter> flag is used to make the test suite run
|
---|
222 | through to completion and not stop at the first failure. The GCC test
|
---|
223 | suite is very comprehensive and is almost guaranteed to generate a few
|
---|
224 | failures.</para>
|
---|
225 |
|
---|
226 | <para>For a discussion of test failures that are of particular
|
---|
227 | importance, please see <xref linkend="ch-system-gcc" role="."/></para>
|
---|
228 |
|
---|
229 | <para>Install the package:</para>
|
---|
230 |
|
---|
231 | <screen><userinput remap="install">make install</userinput></screen>
|
---|
232 |
|
---|
233 | <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
|
---|
234 | href="adjusting.xml"
|
---|
235 | xpointer="xpointer(/sect1/caution[1])"/>
|
---|
236 |
|
---|
237 | </sect2>
|
---|
238 |
|
---|
239 | <sect2 role="content">
|
---|
240 | <title/>
|
---|
241 |
|
---|
242 | <para>Details on this package are located in
|
---|
243 | <xref linkend="contents-gcc" role="."/></para>
|
---|
244 |
|
---|
245 | </sect2>
|
---|
246 |
|
---|
247 | </sect1>
|
---|