chapter05/gcc-pass1.xml

   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" xreflabel="gcc-pass1">
   9   <?dbhtml filename="gcc-pass1.html"?>
  10
  11   <sect1info condition="script">
  12     <productname>gcc-pass1</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="../chapter08/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 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
  59 mv -v mpfr-&mpfr-version; mpfr
  60 tar -xf ../gmp-&gmp-version;.tar.xz
  61 mv -v gmp-&gmp-version; gmp
  62 tar -xf ../mpc-&mpc-version;.tar.gz
  63 mv -v mpc-&mpc-version; mpc</userinput></screen>
  64
  65     <para>On x86_64 hosts, set the default directory name for
  66     64-bit libraries to <quote>lib</quote>:</para>
  67
  68 <screen><userinput remap="pre">case $(uname -m) in
  69   x86_64)
  70     sed -e '/m64=/s/lib64/lib/' \
  71         -i.orig gcc/config/i386/t-linux64
  72  ;;
  73 esac</userinput></screen>
  74
  75     <para>The GCC documentation recommends building GCC
  76     in a dedicated build directory:</para>
  77
  78 <screen><userinput remap="pre">mkdir -v build
  79 cd       build</userinput></screen>
  80
  81     <para>Prepare GCC for compilation:</para>
  82
  83 <screen><userinput remap="configure">../configure                                       \
  84     --target=$LFS_TGT                              \
  85     --prefix=$LFS/tools                            \
  86     --with-glibc-version=2.11                      \
  87     --with-sysroot=$LFS                            \
  88     --with-newlib                                  \
  89     --without-headers                              \
  90     --enable-initfini-array                        \
  91     --disable-nls                                  \
  92     --disable-shared                               \
  93     --disable-multilib                             \
  94     --disable-decimal-float                        \
  95     --disable-threads                              \
  96     --disable-libatomic                            \
  97     --disable-libgomp                              \
  98     --disable-libquadmath                          \
  99     --disable-libssp                               \
 100     --disable-libvtv                               \
 101     --disable-libstdcxx                            \
 102     --enable-languages=c,c++</userinput></screen>
 103     <variablelist>
 104       <title>The meaning of the configure options:</title>
 105
 106       <varlistentry>
 107         <term><parameter>--with-glibc-version=2.11</parameter></term>
 108         <listitem>
 109           <para>This option ensures the package will be compatible with the host's
 110           version of glibc.  It is set to the minimum glibc requirement
 111           specified in the <xref linkend="ch-partitioning-hostreqs"/>.</para>
 112         </listitem>
 113       </varlistentry>
 114
 115       <varlistentry>
 116         <term><parameter>--with-newlib</parameter></term>
 117         <listitem>
 118           <para>Since a working C library is not yet available, this ensures
 119           that the inhibit_libc constant is defined when building libgcc. This prevents
 120           the compiling of any code that requires libc support.</para>
 121         </listitem>
 122       </varlistentry>
 123
 124       <varlistentry>
 125         <term><parameter>--without-headers</parameter></term>
 126         <listitem>
 127           <para>When creating a complete cross-compiler, GCC requires
 128           standard headers compatible with the target system. For our
 129           purposes these headers will not be needed. This switch prevents
 130           GCC from looking for them.</para>
 131         </listitem>
 132       </varlistentry>
 133
 134       <varlistentry>
 135         <term><parameter>--enable-initfini-array</parameter></term>
 136         <listitem>
 137           <para>This switch forces the use of some internal data structures
 138           that are needed but cannot be detected when building a cross
 139           compiler.</para>
 140         </listitem>
 141       </varlistentry>
 142
 143       <varlistentry>
 144         <term><parameter>--disable-shared</parameter></term>
 145         <listitem>
 146           <para>This switch forces GCC to link its internal libraries
 147           statically. We need this because the shared libraries require glibc,
 148           which is not yet installed on the target system.</para>
 149         </listitem>
 150       </varlistentry>
 151
 152       <varlistentry>
 153         <term><parameter>--disable-multilib</parameter></term>
 154         <listitem>
 155           <para>On x86_64, LFS does not support a multilib configuration.
 156           This switch is harmless for x86.</para>
 157         </listitem>
 158       </varlistentry>
 159
 160       <varlistentry>
 161         <term><parameter>--disable-decimal-float, --disable-threads,
 162               --disable-libatomic, --disable-libgomp,
 163         --disable-libquadmath, --disable-libssp, --disable-libvtv,
 164         --disable-libstdcxx</parameter></term>
 165         <listitem>
 166           <para>These switches disable support for the decimal floating point
 167           extension, threading, libatomic, libgomp, libquadmath, libssp,
 168           libvtv, and the C++ standard library respectively. These features
 169           will fail to compile when building a cross-compiler and are not
 170           necessary for the task of cross-compiling the temporary libc.</para>
 171         </listitem>
 172       </varlistentry>
 173
 174       <varlistentry>
 175         <term><parameter>--enable-languages=c,c++</parameter></term>
 176         <listitem>
 177           <para>This option ensures that only the C and C++ compilers are built.
 178           These are the only languages needed now.</para>
 179         </listitem>
 180       </varlistentry>
 181
 182     </variablelist>
 183
 184     <para>Compile GCC by running:</para>
 185
 186 <screen><userinput remap="make">make</userinput></screen>
 187
 188     <para>Install the package:</para>
 189
 190     <screen><userinput remap="install">make install</userinput></screen>
 191
 192     <para>This build of GCC has installed a couple of internal system
 193     headers.  Normally one of them, <filename>limits.h</filename>, would in turn
 194     include the corresponding system <filename>limits.h</filename> header, in
 195     this case, <filename>$LFS/usr/include/limits.h</filename>. However, at the
 196     time of this build of gcc <filename>$LFS/usr/include/limits.h</filename>
 197     does not exist, so the internal header that has just been installed is a
 198     partial, self-contained file and does not include the extended features of
 199     the system header. This is adequate for building glibc, but the full
 200     internal header will be needed later.  Create a full version of the internal
 201     header using a command that is identical to what the GCC build system does
 202     in normal circumstances:</para>
 203
 204 <screen><userinput remap="install">cd ..
 205 cat gcc/limitx.h gcc/glimits.h gcc/limity.h > \
 206   `dirname $($LFS_TGT-gcc -print-libgcc-file-name)`/install-tools/include/limits.h</userinput></screen>
 207   </sect2>
 208
 209   <sect2 role="content">
 210     <title/>
 211
 212     <para>Details on this package are located in
 213     <xref linkend="contents-gcc" role="."/></para>
 214
 215   </sect2>
 216
 217 </sect1>