source: chapter08/strippingagain.xml@ 85cd74c

ml-11.0 multilib
Last change on this file since 85cd74c was 85cd74c, checked in by Thomas Trepl (Moody) <thomas@…>, 13 months ago

Merge upstream changes

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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. These 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>And, <command>strip</command> will overwrite the binary or library
34 file. This may crash the processes using code or data from the file. If
35 the process running <command>strip</command> itself is affected, the
36 binary or library being stripped may be destroyed. This may make the
37 system completely unusable. To avoid it, we'll copy some libraries and
38 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
86for BIN in $online_usrbin; do
87 cp /usr/bin/$BIN /tmp/$BIN
88 strip --strip-all /tmp/$BIN
89 install -vm755 /tmp/$BIN /usr/bin
90 rm /tmp/$BIN
91done
92
93for LIB in $online_usrlib; do
94 cp /usr/lib/$LIB /tmp/$LIB
95 strip --strip-unneeded /tmp/$LIB
96 install -vm755 /tmp/$LIB /usr/lib
97 rm /tmp/$LIB
98done</userinput><userinput arch="ml_32,ml_all">
99for LIB in $online_usrlib; do
100 cp /usr/lib32/$LIB /tmp/$LIB
101 strip --strip-unneeded /tmp/$LIB
102 install -vm755 /tmp/$LIB /usr/lib32
103 rm /tmp/$LIB
104done</userinput><userinput arch="ml_x32,ml_all">
105for LIB in $online_usrlib; do
106 cp /usr/libx32/$LIB /tmp/$LIB
107 strip --strip-unneeded /tmp/$LIB
108 install -vm755 /tmp/$LIB /usr/libx32
109 rm /tmp/$LIB
110done</userinput><userinput>
111
112find /usr/lib -type f -name \*.a \
113 -exec strip --strip-debug {} ';'
114
115for i in $(find /usr/lib -type f -name \*.so* ! -name \*dbg); do
116 case "$online_usrlib $save_usrlib" in
117 *$(basename $i)* ) ;;
118 * ) strip --strip-unneeded $i ;;
119 esac
120done</userinput><userinput arch="ml_32,ml_all">
121for i in $(find /usr/lib32 -type f -name \*.so* ! -name \*dbg); do
122 case "$online_usrlib $save_usrlib" in
123 *$(basename $i)* ) ;;
124 * ) strip --strip-unneeded $i ;;
125 esac
126done</userinput><userinput arch="ml_x32,ml_all">
127for i in $(find /usr/libx32 -type f -name \*.so* ! -name \*dbg); do
128 case "$online_usrlib $save_usrlib" in
129 *$(basename $i)* ) ;;
130 * ) strip --strip-unneeded $i ;;
131 esac
132done</userinput><userinput>
133
134for i in $(find /usr/bin -type f); do
135 case "$online_usrbin" in
136 *$(basename $i)* ) ;;
137 * ) strip --strip-all $i ;;
138 esac
139done
140
141find /usr/{sbin,libexec} -type f \
142 -exec strip --strip-all {} ';'
143
144unset BIN LIB save_usrlib online_usrbin online_usrlib
145</userinput></screen>
146
147 <para>A large number of files will be reported as having their file
148 format not recognized. These warnings can be safely ignored. These
149 warnings indicate that those files are scripts instead of
150 binaries.</para>
151
152</sect1>
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