source: chapter08/strippingagain.xml@ 64a306d

ml-11.0 multilib
Last change on this file since 64a306d was 64a306d, checked in by Thomas Trepl (Moody) <thomas@…>, 13 months ago

Automatic merge of trunk into multilib

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File size: 5.8 KB
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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-strippingagain">
9 <?dbhtml filename="strippingagain.html"?>
10
11 <title>Stripping Again</title>
12
13 <para>This section is optional. If the intended user is not a
14 programmer and does not plan to do
15 any debugging on the system software, the system size can be decreased
16 by about 2 GB by removing the debugging symbols from binaries and
17 libraries. This causes no inconvenience other than not being able to
18 debug the software fully anymore.</para>
19
20 <para>Most people who use the commands mentioned below do not
21 experience any difficulties. However, it is easy to make a typo and
22 render the new system unusable, so before running the
23 <command>strip</command> commands, it is a good idea to make a
24 backup of the LFS system in its current state.</para>
25
26 <para>The debugging symbols for selected libraries are placed
27 in separate files. This debugging information is needed if running
28 regression tests that use <ulink
29 url='&blfs-book;/general/valgrind.html'>valgrind</ulink> or <ulink
30 url='&blfs-book;/general/gdb.html'>gdb</ulink> later in BLFS.
31 </para>
32
33 <para>Note that <command>strip</command> will overwrite the binary or library
34 file it is processing. This may crash the processes using code or data from
35 the file. If the process running <command>strip</command> itself is
36 affected, the binary or library being stripped may be destroyed. This may
37 make the system completely unusable. To avoid it, we'll copy some libraries
38 and binaries into <filename class="directory">/tmp</filename>, strip them
39 there, and install them back with the <command>install</command> command.
40 Read the related entry in <xref linkend="pkgmgmt-upgrade-issues"/> for the
41 rationale to use the <command>install</command> command here.</para>
42
43<!-- also of interest are libgfortan, libgo, libgomp, and libobjc from GCC -->
44
45<!--<screen><userinput>save_lib="ld-2.25.so libc-2.25.so libpthread-2.25.so libthread_db-1.0.so"-->
46<screen><userinput>save_usrlib="ld-&glibc-version;.so libc-&glibc-version;.so libpthread-&glibc-version;.so libthread_db-&libthread_db-version;.so
47 libquadmath.so.&libquadmath-version; libstdc++.so.&libstdcpp-version;
48 libitm.so.&libitm-version; libatomic.so.&libatomic-version;" <!-- libcilkrts.so.&libcilkrts-version;-->
49
50cd /usr/lib
51for LIB in $save_usrlib; do
52 objcopy --only-keep-debug $LIB $LIB.dbg
53 cp $LIB /tmp/$LIB
54 strip --strip-unneeded /tmp/$LIB
55 objcopy --add-gnu-debuglink=$LIB.dbg /tmp/$LIB
56 install -vm755 /tmp/$LIB /usr/lib
57 rm /tmp/$LIB
58done</userinput>
59<userinput arch="ml_32,ml_all">
60cd /usr/lib32
61for LIB in $save_usrlib; do
62 objcopy --only-keep-debug $LIB $LIB.dbg
63 cp $LIB /tmp/$LIB
64 strip --strip-unneeded /tmp/$LIB
65 objcopy --add-gnu-debuglink=$LIB.dbg /tmp/$LIB
66 install -vm755 /tmp/$LIB /usr/lib32
67 rm /tmp/$LIB
68done</userinput>
69<userinput arch="ml_x32,ml_all">
70cd /usr/libx32
71for LIB in $save_usrlib; do
72 objcopy --only-keep-debug $LIB $LIB.dbg
73 cp $LIB /tmp/$LIB
74 strip --strip-unneeded /tmp/$LIB
75 objcopy --add-gnu-debuglink=$LIB.dbg /tmp/$LIB
76 install -vm755 /tmp/$LIB /usr/libx32
77 rm /tmp/$LIB
78done</userinput><userinput>
79
80online_usrbin="bash find strip"
81online_usrlib="libbfd-&binutils-version;.so libdl-&glibc-version;.so
82 libhistory.so.&readline-version; libncursesw.so.&ncurses-version;
83 libm-&glibc-version;.so libreadline.so.&readline-version;
84 libz.so.&zlib-version;
85 $(cd /usr/lib; find libnss*.so* -type f)"
86
87for BIN in $online_usrbin; do
88 cp /usr/bin/$BIN /tmp/$BIN
89 strip --strip-all /tmp/$BIN
90 install -vm755 /tmp/$BIN /usr/bin
91 rm /tmp/$BIN
92done
93
94for LIB in $online_usrlib; do
95 cp /usr/lib/$LIB /tmp/$LIB
96 strip --strip-unneeded /tmp/$LIB
97 install -vm755 /tmp/$LIB /usr/lib
98 rm /tmp/$LIB
99done</userinput><userinput arch="ml_32,ml_all">
100for LIB in $online_usrlib; do
101 cp /usr/lib32/$LIB /tmp/$LIB
102 strip --strip-unneeded /tmp/$LIB
103 install -vm755 /tmp/$LIB /usr/lib32
104 rm /tmp/$LIB
105done</userinput><userinput arch="ml_x32,ml_all">
106for LIB in $online_usrlib; do
107 cp /usr/libx32/$LIB /tmp/$LIB
108 strip --strip-unneeded /tmp/$LIB
109 install -vm755 /tmp/$LIB /usr/libx32
110 rm /tmp/$LIB
111done</userinput><userinput>
112
113find /usr/lib -type f -name \*.a \
114 -exec strip --strip-debug {} ';'
115
116for i in $(find /usr/lib -type f -name \*.so* ! -name \*dbg); do
117 case "$online_usrlib $save_usrlib" in
118 *$(basename $i)* )
119 ;;
120 * ) strip --strip-unneeded $i
121 ;;
122 esac
123done</userinput><userinput arch="ml_32,ml_all">
124for i in $(find /usr/lib32 -type f -name \*.so* ! -name \*dbg); do
125 case "$online_usrlib $save_usrlib" in
126 *$(basename $i)* ) ;;
127 * ) strip --strip-unneeded $i ;;
128 esac
129done</userinput><userinput arch="ml_x32,ml_all">
130for i in $(find /usr/libx32 -type f -name \*.so* ! -name \*dbg); do
131 case "$online_usrlib $save_usrlib" in
132 *$(basename $i)* ) ;;
133 * ) strip --strip-unneeded $i ;;
134 esac
135done</userinput><userinput>
136
137for i in $(find /usr/bin -type f); do
138 case "$online_usrbin" in
139 *$(basename $i)* )
140 ;;
141 * ) strip --strip-all $i
142 ;;
143 esac
144done
145
146find /usr/{sbin,libexec} -type f \
147 -exec strip --strip-all {} ';'
148
149unset BIN LIB save_usrlib online_usrbin online_usrlib
150</userinput></screen>
151
152 <para>A large number of files will be reported as having their file
153 format not recognized. These warnings can be safely ignored. These
154 warnings indicate that those files are scripts instead of
155 binaries.</para>
156
157</sect1>
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