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1 | Installing the GNU C Library |
2 | **************************** | |
41aa20c2 | 3 | |
6a3951a0 | 4 | Before you do anything else, you should read the FAQ at |
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5 | <https://sourceware.org/glibc/wiki/FAQ>. It answers common questions |
6 | and describes problems you may experience with compilation and | |
7 | installation. | |
41aa20c2 | 8 | |
00c1176b | 9 | You will need recent versions of several GNU tools: definitely GCC |
fe959e1e | 10 | and GNU Make, and possibly others. *Note Tools for Compilation::, |
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11 | below. |
12 | ||
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13 | Configuring and compiling the GNU C Library |
14 | =========================================== | |
00c1176b | 15 | |
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16 | The GNU C Library cannot be compiled in the source directory. You must |
17 | build it in a separate build directory. For example, if you have | |
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18 | unpacked the GNU C Library sources in '/src/gnu/glibc-VERSION', create a |
19 | directory '/src/gnu/glibc-build' to put the object files in. This | |
20 | allows removing the whole build directory in case an error occurs, which | |
21 | is the safest way to get a fresh start and should always be done. | |
00c1176b | 22 | |
a8db092e | 23 | From your object directory, run the shell script 'configure' located |
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24 | at the top level of the source tree. In the scenario above, you'd type |
25 | ||
f1e86fca | 26 | $ ../glibc-VERSION/configure ARGS... |
00c1176b | 27 | |
3858bf28 | 28 | Please note that even though you're building in a separate build |
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29 | directory, the compilation may need to create or modify files and |
30 | directories in the source directory. | |
f05f5ca3 | 31 | |
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32 | 'configure' takes many options, but the only one that is usually |
33 | mandatory is '--prefix'. This option tells 'configure' where you want | |
34 | the GNU C Library installed. This defaults to '/usr/local', but the | |
1f77f049 | 35 | normal setting to install as the standard system library is |
a8db092e | 36 | '--prefix=/usr' for GNU/Linux systems and '--prefix=' (an empty prefix) |
1f77f049 | 37 | for GNU/Hurd systems. |
00c1176b | 38 | |
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39 | It may also be useful to pass 'CC=COMPILER' and 'CFLAGS=FLAGS' |
40 | arguments to 'configure'. 'CC' selects the C compiler that will be | |
41 | used, and 'CFLAGS' sets optimization options for the compiler. Any | |
42 | compiler options required for all compilations, such as options | |
43 | selecting an ABI or a processor for which to generate code, should be | |
44 | included in 'CC'. Options that may be overridden by the GNU C Library | |
45 | build system for particular files, such as for optimization and | |
46 | debugging, should go in 'CFLAGS'. The default value of 'CFLAGS' is '-g | |
47 | -O2', and the GNU C Library cannot be compiled without optimization, so | |
48 | if 'CFLAGS' is specified it must enable optimization. For example: | |
49 | ||
50 | $ ../glibc-VERSION/configure CC="gcc -m32" CFLAGS="-O3" | |
00c1176b | 51 | |
bd952512 | 52 | The following list describes all of the available options for |
a8db092e | 53 | 'configure': |
00c1176b | 54 | |
a8db092e | 55 | '--prefix=DIRECTORY' |
00c1176b | 56 | Install machine-independent data files in subdirectories of |
a8db092e | 57 | 'DIRECTORY'. The default is to install in '/usr/local'. |
00c1176b | 58 | |
a8db092e | 59 | '--exec-prefix=DIRECTORY' |
00c1176b | 60 | Install the library and other machine-dependent files in |
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61 | subdirectories of 'DIRECTORY'. The default is to the '--prefix' |
62 | directory if that option is specified, or '/usr/local' otherwise. | |
00c1176b | 63 | |
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64 | '--with-headers=DIRECTORY' |
65 | Look for kernel header files in DIRECTORY, not '/usr/include'. The | |
66 | GNU C Library needs information from the kernel's header files | |
1f77f049 | 67 | describing the interface to the kernel. The GNU C Library will |
a8db092e | 68 | normally look in '/usr/include' for them, but if you specify this |
1f77f049 | 69 | option, it will look in DIRECTORY instead. |
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70 | |
71 | This option is primarily of use on a system where the headers in | |
a8db092e | 72 | '/usr/include' come from an older version of the GNU C Library. |
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73 | Conflicts can occasionally happen in this case. You can also use |
74 | this option if you want to compile the GNU C Library with a newer | |
a8db092e | 75 | set of kernel headers than the ones found in '/usr/include'. |
41aa20c2 | 76 | |
a8db092e | 77 | '--enable-kernel=VERSION' |
90d1d40b | 78 | This option is currently only useful on GNU/Linux systems. The |
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79 | VERSION parameter should have the form X.Y.Z and describes the |
80 | smallest version of the Linux kernel the generated library is | |
81 | expected to support. The higher the VERSION number is, the less | |
82 | compatibility code is added, and the faster the code gets. | |
83 | ||
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84 | '--with-binutils=DIRECTORY' |
85 | Use the binutils (assembler and linker) in 'DIRECTORY', not the | |
6736e93b | 86 | ones the C compiler would default to. You can use this option if |
41aa20c2 | 87 | the default binutils on your system cannot deal with all the |
a8db092e | 88 | constructs in the GNU C Library. In that case, 'configure' will |
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89 | detect the problem and suppress these constructs, so that the |
90 | library will still be usable, but functionality may be lost--for | |
91 | example, you can't build a shared libc with old binutils. | |
41aa20c2 | 92 | |
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93 | '--with-nonshared-cflags=CFLAGS' |
94 | Use additional compiler flags CFLAGS to build the parts of the | |
95 | library which are always statically linked into applications and | |
96 | libraries even with shared linking (that is, the object files | |
97 | contained in 'lib*_nonshared.a' libraries). The build process will | |
98 | automatically use the appropriate flags, but this option can be | |
99 | used to set additional flags required for building applications and | |
100 | libraries, to match local policy. For example, if such a policy | |
101 | requires that all code linked into applications must be built with | |
102 | source fortification, | |
103 | '--with-nonshared-cflags=-Wp,-D_FORTIFY_SOURCE=2' will make sure | |
104 | that the objects in 'libc_nonshared.a' are compiled with this flag | |
105 | (although this will not affect the generated code in this | |
106 | particular case and potentially change debugging information and | |
107 | metadata only). | |
108 | ||
a8db092e | 109 | '--disable-shared' |
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110 | Don't build shared libraries even if it is possible. Not all |
111 | systems support shared libraries; you need ELF support and | |
112 | (currently) the GNU linker. | |
41aa20c2 | 113 | |
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114 | '--enable-static-pie' |
115 | Enable static position independent executable (static PIE) support. | |
116 | Static PIE is similar to static executable, but can be loaded at | |
117 | any address without help from a dynamic linker. All static | |
118 | programs as well as static tests are built as static PIE, except | |
119 | for those marked with no-pie. The resulting glibc can be used with | |
120 | the GCC option, -static-pie, which is available with GCC 8 or | |
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121 | above, to create static PIE. This option also implies that glibc |
122 | programs and tests are created as dynamic position independent | |
123 | executables (PIE) by default. | |
9d7a3741 | 124 | |
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125 | '--enable-cet' |
126 | Enable Intel Control-flow Enforcement Technology (CET) support. | |
127 | When the GNU C Library is built with '--enable-cet', the resulting | |
128 | library is protected with indirect branch tracking (IBT) and shadow | |
129 | stack (SHSTK). When CET is enabled, the GNU C Library is | |
130 | compatible with all existing executables and shared libraries. | |
131 | This feature is currently supported on i386, x86_64 and x32 with | |
132 | GCC 8 and binutils 2.29 or later. Note that when CET is enabled, | |
133 | the GNU C Library requires CPUs capable of multi-byte NOPs, like | |
134 | x86-64 processors as well as Intel Pentium Pro or newer. | |
135 | ||
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136 | NOTE: '--enable-cet' has been tested for i686, x86_64 and x32 on |
137 | non-CET processors. '--enable-cet' has been tested for x86_64 and | |
138 | x32 on CET SDVs, but Intel CET support hasn't been validated for | |
139 | i686. | |
140 | ||
a8db092e | 141 | '--disable-profile' |
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142 | Don't build libraries with profiling information. You may want to |
143 | use this option if you don't plan to do profiling. | |
41aa20c2 | 144 | |
a8db092e | 145 | '--enable-static-nss' |
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146 | Compile static versions of the NSS (Name Service Switch) libraries. |
147 | This is not recommended because it defeats the purpose of NSS; a | |
148 | program linked statically with the NSS libraries cannot be | |
149 | dynamically reconfigured to use a different name database. | |
150 | ||
a8db092e | 151 | '--enable-hardcoded-path-in-tests' |
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152 | By default, dynamic tests are linked to run with the installed C |
153 | library. This option hardcodes the newly built C library path in | |
154 | dynamic tests so that they can be invoked directly. | |
155 | ||
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156 | '--disable-timezone-tools' |
157 | By default, timezone related utilities ('zic', 'zdump', and | |
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158 | 'tzselect') are installed with the GNU C Library. If you are |
159 | building these independently (e.g. by using the 'tzcode' package), | |
160 | then this option will allow disabling the install of these. | |
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161 | |
162 | Note that you need to make sure the external tools are kept in sync | |
163 | with the versions that the GNU C Library expects as the data | |
164 | formats may change over time. Consult the 'timezone' subdirectory | |
165 | for more details. | |
166 | ||
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167 | '--enable-stack-protector' |
168 | '--enable-stack-protector=strong' | |
169 | '--enable-stack-protector=all' | |
170 | Compile the C library and all other parts of the glibc package | |
171 | (including the threading and math libraries, NSS modules, and | |
172 | transliteration modules) using the GCC '-fstack-protector', | |
173 | '-fstack-protector-strong' or '-fstack-protector-all' options to | |
174 | detect stack overruns. Only the dynamic linker and a small number | |
175 | of routines called directly from assembler are excluded from this | |
176 | protection. | |
177 | ||
2d6ab5df | 178 | '--enable-bind-now' |
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179 | Disable lazy binding for installed shared objects and programs. |
180 | This provides additional security hardening because it enables full | |
181 | RELRO and a read-only global offset table (GOT), at the cost of | |
182 | slightly increased program load times. | |
2d6ab5df | 183 | |
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184 | '--enable-pt_chown' |
185 | The file 'pt_chown' is a helper binary for 'grantpt' (*note | |
186 | Pseudo-Terminals: Allocation.) that is installed setuid root to fix | |
187 | up pseudo-terminal ownership. It is not built by default because | |
188 | systems using the Linux kernel are commonly built with the 'devpts' | |
189 | filesystem enabled and mounted at '/dev/pts', which manages | |
190 | pseudo-terminal ownership automatically. By using | |
191 | '--enable-pt_chown', you may build 'pt_chown' and install it setuid | |
192 | and owned by 'root'. The use of 'pt_chown' introduces additional | |
193 | security risks to the system and you should enable it only if you | |
194 | understand and accept those risks. | |
195 | ||
196 | '--disable-werror' | |
197 | By default, the GNU C Library is built with '-Werror'. If you wish | |
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198 | to build without this option (for example, if building with a newer |
199 | version of GCC than this version of the GNU C Library was tested | |
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200 | with, so new warnings cause the build with '-Werror' to fail), you |
201 | can configure with '--disable-werror'. | |
202 | ||
21933112 | 203 | '--disable-mathvec' |
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204 | By default for x86_64, the GNU C Library is built with the vector |
205 | math library. Use this option to disable the vector math library. | |
21933112 | 206 | |
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207 | '--enable-tunables' |
208 | Tunables support allows additional library parameters to be | |
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209 | customized at runtime. This feature is enabled by default. This |
210 | option can take the following values: | |
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211 | |
212 | 'yes' | |
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213 | This is the default if no option is passed to configure. This |
214 | enables tunables and selects the default frontend (currently | |
215 | 'valstring'). | |
216 | ||
217 | 'no' | |
218 | This option disables tunables. | |
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219 | |
220 | 'valstring' | |
221 | This enables tunables and selects the 'valstring' frontend for | |
222 | tunables. This frontend allows users to specify tunables as a | |
223 | colon-separated list in a single environment variable | |
224 | 'GLIBC_TUNABLES'. | |
67e58f39 | 225 | |
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226 | '--enable-obsolete-nsl' |
227 | By default, libnsl is only built as shared library for backward | |
228 | compatibility and the NSS modules libnss_compat, libnss_nis and | |
229 | libnss_nisplus are not built at all. Use this option to enable | |
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230 | libnsl with all depending NSS modules and header files. For |
231 | architectures and ABIs that have been added after version 2.28 of | |
232 | the GNU C Library this option is not available, and the libnsl | |
233 | compatibility library is not built. | |
a640393a | 234 | |
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235 | '--disable-crypt' |
236 | Do not install the passphrase-hashing library 'libcrypt' or the | |
237 | header file 'crypt.h'. 'unistd.h' will still declare the function | |
238 | 'crypt'. Using this option does not change the set of programs | |
239 | that may need to be linked with '-lcrypt'; it only means that the | |
240 | GNU C Library will not provide that library. | |
241 | ||
242 | This option is for hackers and distributions experimenting with | |
243 | independently-maintained implementations of libcrypt. It may | |
244 | become the default in a future release. | |
245 | ||
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246 | '--disable-experimental-malloc' |
247 | By default, a per-thread cache is enabled in 'malloc'. While this | |
248 | cache can be disabled on a per-application basis using tunables | |
249 | (set glibc.malloc.tcache_count to zero), this option can be used to | |
250 | remove it from the build completely. | |
251 | ||
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252 | '--build=BUILD-SYSTEM' |
253 | '--host=HOST-SYSTEM' | |
254 | These options are for cross-compiling. If you specify both options | |
255 | and BUILD-SYSTEM is different from HOST-SYSTEM, 'configure' will | |
256 | prepare to cross-compile the GNU C Library from BUILD-SYSTEM to be | |
257 | used on HOST-SYSTEM. You'll probably need the '--with-headers' | |
258 | option too, and you may have to override CONFIGURE's selection of | |
259 | the compiler and/or binutils. | |
260 | ||
261 | If you only specify '--host', 'configure' will prepare for a native | |
262 | compile but use what you specify instead of guessing what your | |
263 | system is. This is most useful to change the CPU submodel. For | |
264 | example, if 'configure' guesses your machine as 'i686-pc-linux-gnu' | |
265 | but you want to compile a library for 586es, give | |
266 | '--host=i586-pc-linux-gnu' or just '--host=i586-linux' and add the | |
267 | appropriate compiler flags ('-mcpu=i586' will do the trick) to | |
db9881ec | 268 | 'CC'. |
1792d4db | 269 | |
a8db092e | 270 | If you specify just '--build', 'configure' will get confused. |
41aa20c2 | 271 | |
a8db092e | 272 | '--with-pkgversion=VERSION' |
8b748aed | 273 | Specify a description, possibly including a build number or build |
a8db092e | 274 | date, of the binaries being built, to be included in '--version' |
8b748aed | 275 | output from programs installed with the GNU C Library. For |
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276 | example, '--with-pkgversion='FooBar GNU/Linux glibc build 123''. |
277 | The default value is 'GNU libc'. | |
8b748aed | 278 | |
a8db092e | 279 | '--with-bugurl=URL' |
8b748aed | 280 | Specify the URL that users should visit if they wish to report a |
a8db092e | 281 | bug, to be included in '--help' output from programs installed with |
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282 | the GNU C Library. The default value refers to the main |
283 | bug-reporting information for the GNU C Library. | |
284 | ||
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285 | To build the library and related programs, type 'make'. This will |
286 | produce a lot of output, some of which may look like errors from 'make' | |
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287 | but aren't. Look for error messages from 'make' containing '***'. |
288 | Those indicate that something is seriously wrong. | |
41aa20c2 | 289 | |
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290 | The compilation process can take a long time, depending on the |
291 | configuration and the speed of your machine. Some complex modules may | |
292 | take a very long time to compile, as much as several minutes on slower | |
293 | machines. Do not panic if the compiler appears to hang. | |
00c1176b | 294 | |
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295 | If you want to run a parallel make, simply pass the '-j' option with |
296 | an appropriate numeric parameter to 'make'. You need a recent GNU | |
297 | 'make' version, though. | |
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298 | |
299 | To build and run test programs which exercise some of the library | |
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300 | facilities, type 'make check'. If it does not complete successfully, do |
301 | not use the built library, and report a bug after verifying that the | |
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302 | problem is not already known. *Note Reporting Bugs::, for instructions |
303 | on reporting bugs. Note that some of the tests assume they are not | |
a8db092e | 304 | being run by 'root'. We recommend you compile and test the GNU C |
1f77f049 | 305 | Library as an unprivileged user. |
41aa20c2 | 306 | |
8d4b5a8a | 307 | Before reporting bugs make sure there is no problem with your system. |
6736e93b | 308 | The tests (and later installation) use some pre-existing files of the |
a8db092e | 309 | system such as '/etc/passwd', '/etc/nsswitch.conf' and others. These |
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310 | files must all contain correct and sensible content. |
311 | ||
a8db092e | 312 | Normally, 'make check' will run all the tests before reporting all |
d6fe5e58 | 313 | problems found and exiting with error status if any problems occurred. |
a8db092e | 314 | You can specify 'stop-on-test-failure=y' when running 'make check' to |
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315 | make the test run stop and exit with an error status immediately when a |
316 | failure occurs. | |
317 | ||
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318 | To format the 'GNU C Library Reference Manual' for printing, type |
319 | 'make dvi'. You need a working TeX installation to do this. The | |
320 | distribution builds the on-line formatted version of the manual, as Info | |
321 | files, as part of the build process. You can build them manually with | |
322 | 'make info'. | |
1792d4db | 323 | |
c0389ee4 | 324 | The library has a number of special-purpose configuration parameters |
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325 | which you can find in 'Makeconfig'. These can be overwritten with the |
326 | file 'configparms'. To change them, create a 'configparms' in your | |
327 | build directory and add values as appropriate for your system. The file | |
328 | is included and parsed by 'make' and has to follow the conventions for | |
329 | makefiles. | |
c0389ee4 | 330 | |
1f77f049 | 331 | It is easy to configure the GNU C Library for cross-compilation by |
a8db092e | 332 | setting a few variables in 'configparms'. Set 'CC' to the |
c0389ee4 | 333 | cross-compiler for the target you configured the library for; it is |
a8db092e | 334 | important to use this same 'CC' value when running 'configure', like |
db9881ec | 335 | this: 'configure TARGET CC=TARGET-gcc'. Set 'BUILD_CC' to the compiler |
6736e93b | 336 | to use for programs run on the build system as part of compiling the |
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337 | library. You may need to set 'AR' to cross-compiling versions of 'ar' |
338 | if the native tools are not configured to work with object files for the | |
339 | target you configured for. When cross-compiling the GNU C Library, it | |
340 | may be tested using 'make check | |
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341 | test-wrapper="SRCDIR/scripts/cross-test-ssh.sh HOSTNAME"', where SRCDIR |
342 | is the absolute directory name for the main source directory and | |
343 | HOSTNAME is the host name of a system that can run the newly built | |
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344 | binaries of the GNU C Library. The source and build directories must be |
345 | visible at the same locations on both the build system and HOSTNAME. | |
c0389ee4 | 346 | |
a8db092e | 347 | In general, when testing the GNU C Library, 'test-wrapper' may be set |
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348 | to the name and arguments of any program to run newly built binaries. |
349 | This program must preserve the arguments to the binary being run, its | |
8540f6d2 | 350 | working directory and the standard input, output and error file |
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351 | descriptors. If 'TEST-WRAPPER env' will not work to run a program with |
352 | environment variables set, then 'test-wrapper-env' must be set to a | |
8540f6d2 | 353 | program that runs a newly built program with environment variable |
a8db092e | 354 | assignments in effect, those assignments being specified as 'VAR=VALUE' |
8540f6d2 | 355 | before the name of the program to be run. If multiple assignments to |
a8db092e | 356 | the same variable are specified, the last assignment specified must take |
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357 | precedence. Similarly, if 'TEST-WRAPPER env -i' will not work to run a |
358 | program with an environment completely empty of variables except those | |
359 | directly assigned, then 'test-wrapper-env-only' must be set; its use has | |
360 | the same syntax as 'test-wrapper-env', the only difference in its | |
361 | semantics being starting with an empty set of environment variables | |
362 | rather than the ambient set. | |
0eb69512 | 363 | |
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364 | Installing the C Library |
365 | ======================== | |
41aa20c2 | 366 | |
80ed68b7 | 367 | To install the library and its header files, and the Info files of the |
a8db092e | 368 | manual, type 'make install'. This will build things, if necessary, |
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369 | before installing them; however, you should still compile everything |
370 | first. If you are installing the GNU C Library as your primary C | |
371 | library, we recommend that you shut the system down to single-user mode | |
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372 | first, and reboot afterward. This minimizes the risk of breaking things |
373 | when the library changes out from underneath. | |
1792d4db | 374 | |
a8db092e | 375 | 'make install' will do the entire job of upgrading from a previous |
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376 | installation of the GNU C Library version 2.x. There may sometimes be |
377 | headers left behind from the previous installation, but those are | |
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378 | generally harmless. If you want to avoid leaving headers behind you can |
379 | do things in the following order. | |
c0389ee4 | 380 | |
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381 | You must first build the library ('make'), optionally check it ('make |
382 | check'), switch the include directories and then install ('make | |
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383 | install'). The steps must be done in this order. Not moving the |
384 | directory before install will result in an unusable mixture of header | |
385 | files from both libraries, but configuring, building, and checking the | |
386 | library requires the ability to compile and run programs against the old | |
a8db092e | 387 | library. The new '/usr/include', after switching the include |
02c4bbad | 388 | directories and before installing the library should contain the Linux |
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389 | headers, but nothing else. If you do this, you will need to restore any |
390 | headers from libraries other than the GNU C Library yourself after | |
1f77f049 | 391 | installing the library. |
c0389ee4 | 392 | |
1f77f049 | 393 | You can install the GNU C Library somewhere other than where you |
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394 | configured it to go by setting the 'DESTDIR' GNU standard make variable |
395 | on the command line for 'make install'. The value of this variable is | |
1f77f049 | 396 | prepended to all the paths for installation. This is useful when |
a8db092e | 397 | setting up a chroot environment or preparing a binary distribution. The |
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398 | directory should be specified with an absolute file name. Installing |
399 | with the 'prefix' and 'exec_prefix' GNU standard make variables set is | |
400 | not supported. | |
1792d4db | 401 | |
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402 | The GNU C Library includes a daemon called 'nscd', which you may or |
403 | may not want to run. 'nscd' caches name service lookups; it can | |
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404 | dramatically improve performance with NIS+, and may help with DNS as |
405 | well. | |
1792d4db | 406 | |
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407 | One auxiliary program, '/usr/libexec/pt_chown', is installed setuid |
408 | 'root' if the '--enable-pt_chown' configuration option is used. This | |
409 | program is invoked by the 'grantpt' function; it sets the permissions on | |
410 | a pseudoterminal so it can be used by the calling process. If you are | |
411 | using a Linux kernel with the 'devpts' filesystem enabled and mounted at | |
412 | '/dev/pts', you don't need this program. | |
41aa20c2 | 413 | |
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414 | After installation you should configure the timezone and install |
415 | locales for your system. The time zone configuration ensures that your | |
416 | system time matches the time for your current timezone. The locales | |
417 | ensure that the display of information on your system matches the | |
418 | expectations of your language and geographic region. | |
419 | ||
420 | The GNU C Library is able to use two kinds of localization | |
421 | information sources, the first is a locale database named | |
422 | 'locale-archive' which is generally installed as | |
423 | '/usr/lib/locale/locale-archive'. The locale archive has the benefit of | |
424 | taking up less space and being very fast to load, but only if you plan | |
425 | to install sixty or more locales. If you plan to install one or two | |
426 | locales you can instead install individual locales into their self-named | |
427 | directories e.g. '/usr/lib/locale/en_US.utf8'. For example to install | |
428 | the German locale using the character set for UTF-8 with name 'de_DE' | |
429 | into the locale archive issue the command 'localedef -i de_DE -f UTF-8 | |
430 | de_DE', and to install just the one locale issue the command 'localedef | |
431 | --no-archive -i de_DE -f UTF-8 de_DE'. To configure all locales that | |
a8db092e | 432 | are supported by the GNU C Library, you can issue from your build |
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433 | directory the command 'make localedata/install-locales' to install all |
434 | locales into the locale archive or 'make | |
435 | localedata/install-locale-files' to install all locales as files in the | |
436 | default configured locale installation directory (derived from | |
437 | '--prefix' or '--localedir'). To install into an alternative system | |
438 | root use 'DESTDIR' e.g. 'make localedata/install-locale-files | |
439 | DESTDIR=/opt/glibc', but note that this does not change the configured | |
440 | prefix. | |
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441 | |
442 | To configure the locally used timezone, set the 'TZ' environment | |
443 | variable. The script 'tzselect' helps you to select the right value. | |
444 | As an example, for Germany, 'tzselect' would tell you to use | |
445 | 'TZ='Europe/Berlin''. For a system wide installation (the given paths | |
446 | are for an installation with '--prefix=/usr'), link the timezone file | |
447 | which is in '/usr/share/zoneinfo' to the file '/etc/localtime'. For | |
448 | Germany, you might execute 'ln -s /usr/share/zoneinfo/Europe/Berlin | |
bd952512 UD |
449 | /etc/localtime'. |
450 | ||
c9dc3f62 RM |
451 | Recommended Tools for Compilation |
452 | ================================= | |
41aa20c2 | 453 | |
80ed68b7 | 454 | We recommend installing the following GNU tools before attempting to |
1f77f049 | 455 | build the GNU C Library: |
41aa20c2 | 456 | |
f2873d2d | 457 | * GNU 'make' 4.0 or newer |
41aa20c2 | 458 | |
f650932b CD |
459 | As of relase time, GNU 'make' 4.2.1 is the newest verified to work |
460 | to build the GNU C Library. | |
461 | ||
4dcbbc3b | 462 | * GCC 6.2 or newer |
0e7727f7 | 463 | |
4dcbbc3b | 464 | GCC 6.2 or higher is required. In general it is recommended to use |
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465 | the newest version of the compiler that is known to work for |
466 | building the GNU C Library, as newer compilers usually produce | |
df5919df | 467 | better code. As of release time, GCC 9.2.1 is the newest compiler |
4863355a | 468 | verified to work to build the GNU C Library. |
91ea72b7 | 469 | |
50545f5a PM |
470 | For PowerPC 64-bits little-endian (powerpc64le), a GCC version with |
471 | support for '-mno-gnu-attribute', '-mabi=ieeelongdouble', and | |
472 | '-mabi=ibmlondouble' is required. These additional features are | |
473 | required for building the GNU C Library with support for IEEE long | |
474 | double. | |
475 | ||
022dfdce SL |
476 | For multi-arch support it is recommended to use a GCC which has |
477 | been built with support for GNU indirect functions. This ensures | |
478 | that correct debugging information is generated for functions | |
479 | selected by IFUNC resolvers. This support can either be enabled by | |
480 | configuring GCC with '--enable-gnu-indirect-function', or by | |
481 | enabling it by default by setting 'default_gnu_indirect_function' | |
482 | variable for a particular architecture in the GCC source file | |
483 | 'gcc/config.gcc'. | |
484 | ||
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485 | You can use whatever compiler you like to compile programs that use |
486 | the GNU C Library. | |
41aa20c2 | 487 | |
90d1d40b RM |
488 | Check the FAQ for any special compiler issues on particular |
489 | platforms. | |
5713a71e | 490 | |
073e8fa7 | 491 | * GNU 'binutils' 2.25 or later |
41aa20c2 | 492 | |
a8db092e | 493 | You must use GNU 'binutils' (as and ld) to build the GNU C Library. |
7a49a7d5 | 494 | No other assembler or linker has the necessary functionality at the |
df5919df | 495 | moment. As of release time, GNU 'binutils' 2.32 is the newest |
04cb913d | 496 | verified to work to build the GNU C Library. |
41aa20c2 | 497 | |
3a0acbdc PM |
498 | For PowerPC 64-bits little-endian (powerpc64le), 'objcopy' is |
499 | required to support '--update-section'. This option requires | |
500 | binutils 2.26 or newer. | |
501 | ||
a8db092e | 502 | * GNU 'texinfo' 4.7 or later |
41aa20c2 UD |
503 | |
504 | To correctly translate and install the Texinfo documentation you | |
a8db092e | 505 | need this version of the 'texinfo' package. Earlier versions do |
41aa20c2 | 506 | not understand all the tags used in the document, and the |
1792d4db | 507 | installation mechanism for the info files is not present or works |
e7124906 | 508 | differently. As of release time, 'texinfo' 6.6 is the newest |
04cb913d | 509 | verified to work to build the GNU C Library. |
41aa20c2 | 510 | |
a8db092e | 511 | * GNU 'awk' 3.1.2, or higher |
00c1176b | 512 | |
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513 | 'awk' is used in several places to generate files. Some 'gawk' |
514 | extensions are used, including the 'asorti' function, which was | |
2c8f75f7 | 515 | introduced in version 3.1.2 of 'gawk'. As of release time, 'gawk' |
df5919df | 516 | version 5.0.1 is the newest verified to work to build the GNU C |
2c8f75f7 | 517 | Library. |
41aa20c2 | 518 | |
1faaf703 JB |
519 | * GNU 'bison' 2.7 or later |
520 | ||
521 | 'bison' is used to generate the 'yacc' parser code in the 'intl' | |
df5919df | 522 | subdirectory. As of release time, 'bison' version 3.4.1 is the |
93493119 | 523 | newest verified to work to build the GNU C Library. |
1faaf703 | 524 | |
00c1176b UD |
525 | * Perl 5 |
526 | ||
3c1622eb | 527 | Perl is not required, but if present it is used in some tests and |
053c52b1 | 528 | the 'mtrace' program, to build the GNU C Library manual. As of |
df5919df | 529 | release time 'perl' version 5.30.1 is the newest verified to work |
053c52b1 | 530 | to build the GNU C Library. |
41aa20c2 | 531 | |
a8db092e | 532 | * GNU 'sed' 3.02 or newer |
c0389ee4 | 533 | |
a8db092e | 534 | 'Sed' is used in several places to generate files. Most scripts |
2c8f75f7 | 535 | work with any version of 'sed'. As of release time, 'sed' version |
f650932b | 536 | 4.5 is the newest verified to work to build the GNU C Library. |
c0389ee4 | 537 | |
c6982f7e | 538 | * Python 3.4 or later |
3c1622eb | 539 | |
c6982f7e | 540 | Python is required to build the GNU C Library. As of release time, |
e7124906 | 541 | Python 3.7.4 is the newest verified to work for building and |
330c9d0d | 542 | testing the GNU C Library. |
3c1622eb JM |
543 | |
544 | * PExpect 4.0 | |
545 | ||
546 | The pretty printer tests drive GDB through test programs and | |
547 | compare its output to the printers'. PExpect is used to capture | |
548 | the output of GDB, and should be compatible with the Python version | |
549 | in your system. As of release time PExpect 4.3 is the newest | |
550 | verified to work to test the pretty printers. | |
551 | ||
552 | * GDB 7.8 or later with support for Python 2.7/3.4 or later | |
553 | ||
554 | GDB itself needs to be configured with Python support in order to | |
555 | use the pretty printers. Notice that your system having Python | |
556 | available doesn't imply that GDB supports it, nor that your | |
557 | system's Python and GDB's have the same version. As of release | |
e7124906 | 558 | time GNU 'debugger' 8.3 is the newest verified to work to test the |
330c9d0d | 559 | pretty printers. |
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560 | |
561 | Unless Python, PExpect and GDB with Python support are present, the | |
562 | printer tests will report themselves as 'UNSUPPORTED'. Notice that | |
563 | some of the printer tests require the GNU C Library to be compiled | |
564 | with debugging symbols. | |
565 | ||
a8db092e | 566 | If you change any of the 'configure.ac' files you will also need |
0cc70fcf | 567 | |
a8db092e | 568 | * GNU 'autoconf' 2.69 (exactly) |
41aa20c2 UD |
569 | |
570 | and if you change any of the message translation files you will need | |
571 | ||
a8db092e | 572 | * GNU 'gettext' 0.10.36 or later |
41aa20c2 | 573 | |
f650932b CD |
574 | As of release time, GNU 'gettext' version 0.19.8.1 is the newest |
575 | version verified to work to build the GNU C Library. | |
576 | ||
41aa20c2 UD |
577 | You may also need these packages if you upgrade your source tree using |
578 | patches, although we try to avoid this. | |
579 | ||
c9dc3f62 RM |
580 | Specific advice for GNU/Linux systems |
581 | ===================================== | |
80ed68b7 | 582 | |
a7a93d50 | 583 | If you are installing the GNU C Library on GNU/Linux systems, you need |
5b4ecd3f | 584 | to have the header files from a 3.2 or newer kernel around for |
e9203023 FW |
585 | reference. (For the ia64 architecture, you need version 3.2.18 or newer |
586 | because this is the first version with support for the 'accept4' system | |
587 | call.) These headers must be installed using 'make headers_install'; | |
588 | the headers present in the kernel source directory are not suitable for | |
589 | direct use by the GNU C Library. You do not need to use that kernel, | |
590 | just have its headers installed where the GNU C Library can access them, | |
591 | referred to here as INSTALL-DIRECTORY. The easiest way to do this is to | |
592 | unpack it in a directory such as '/usr/src/linux-VERSION'. In that | |
593 | directory, run 'make headers_install | |
1f77f049 | 594 | INSTALL_HDR_PATH=INSTALL-DIRECTORY'. Finally, configure the GNU C |
a8db092e CD |
595 | Library with the option '--with-headers=INSTALL-DIRECTORY/include'. Use |
596 | the most recent kernel you can get your hands on. (If you are | |
1f77f049 | 597 | cross-compiling the GNU C Library, you need to specify |
a8db092e | 598 | 'ARCH=ARCHITECTURE' in the 'make headers_install' command, where |
1f77f049 | 599 | ARCHITECTURE is the architecture name used by the Linux kernel, such as |
a8db092e | 600 | 'x86' or 'powerpc'.) |
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601 | |
602 | After installing the GNU C Library, you may need to remove or rename | |
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603 | directories such as '/usr/include/linux' and '/usr/include/asm', and |
604 | replace them with copies of directories such as 'linux' and 'asm' from | |
605 | 'INSTALL-DIRECTORY/include'. All directories present in | |
606 | 'INSTALL-DIRECTORY/include' should be copied, except that the GNU C | |
607 | Library provides its own version of '/usr/include/scsi'; the files | |
608 | provided by the kernel should be copied without replacing those provided | |
609 | by the GNU C Library. The 'linux', 'asm' and 'asm-generic' directories | |
610 | are required to compile programs using the GNU C Library; the other | |
611 | directories describe interfaces to the kernel but are not required if | |
612 | not compiling programs using those interfaces. You do not need to copy | |
613 | kernel headers if you did not specify an alternate kernel header source | |
614 | using '--with-headers'. | |
1f77f049 | 615 | |
a7a93d50 | 616 | The Filesystem Hierarchy Standard for GNU/Linux systems expects some |
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617 | components of the GNU C Library installation to be in '/lib' and some in |
618 | '/usr/lib'. This is handled automatically if you configure the GNU C | |
619 | Library with '--prefix=/usr'. If you set some other prefix or allow it | |
620 | to default to '/usr/local', then all the components are installed there. | |
1792d4db | 621 | |
c9dc3f62 RM |
622 | Reporting Bugs |
623 | ============== | |
41aa20c2 | 624 | |
1f77f049 | 625 | There are probably bugs in the GNU C Library. There are certainly |
41aa20c2 UD |
626 | errors and omissions in this manual. If you report them, they will get |
627 | fixed. If you don't, no one will ever know about them and they will | |
628 | remain unfixed for all eternity, if not longer. | |
629 | ||
bd952512 | 630 | It is a good idea to verify that the problem has not already been |
a8db092e | 631 | reported. Bugs are documented in two places: The file 'BUGS' describes |
8b748aed | 632 | a number of well known bugs and the central GNU C Library bug tracking |
a306c790 | 633 | system has a WWW interface at <https://sourceware.org/bugzilla/>. The |
8b748aed JM |
634 | WWW interface gives you access to open and closed reports. A closed |
635 | report normally includes a patch or a hint on solving the problem. | |
6736e93b | 636 | |
a8db092e CD |
637 | To report a bug, first you must find it. With any luck, this will be |
638 | the hard part. Once you've found a bug, make sure it's really a bug. A | |
639 | good way to do this is to see if the GNU C Library behaves the same way | |
640 | some other C library does. If so, probably you are wrong and the | |
641 | libraries are right (but not necessarily). If not, one of the libraries | |
642 | is probably wrong. It might not be the GNU C Library. Many historical | |
643 | Unix C libraries permit things that we don't, such as closing a file | |
644 | twice. | |
1792d4db | 645 | |
1f77f049 | 646 | If you think you have found some way in which the GNU C Library does |
1792d4db | 647 | not conform to the ISO and POSIX standards (*note Standards and |
c0389ee4 | 648 | Portability::), that is definitely a bug. Report it! |
41aa20c2 UD |
649 | |
650 | Once you're sure you've found a bug, try to narrow it down to the | |
651 | smallest test case that reproduces the problem. In the case of a C | |
652 | library, you really only need to narrow it down to one library function | |
653 | call, if possible. This should not be too difficult. | |
654 | ||
655 | The final step when you have a simple test case is to report the bug. | |
5a82c748 | 656 | Do this at <https://www.gnu.org/software/libc/bugs.html>. |
41aa20c2 UD |
657 | |
658 | If you are not sure how a function should behave, and this manual | |
659 | doesn't tell you, that's a bug in the manual. Report that too! If the | |
660 | function's behavior disagrees with the manual, then either the library | |
661 | or the manual has a bug, so report the disagreement. If you find any | |
80ed68b7 RM |
662 | errors or omissions in this manual, please report them to the bug |
663 | database. If you refer to specific sections of the manual, please | |
664 | include the section names for easier identification. |