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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. |
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38 | |
39 | It may also be useful to set the CC and CFLAGS variables in the | |
a8db092e | 40 | environment when running 'configure'. CC selects the C compiler that |
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41 | will be used, and CFLAGS sets optimization options for the compiler. |
42 | ||
bd952512 | 43 | The following list describes all of the available options for |
a8db092e | 44 | 'configure': |
00c1176b | 45 | |
a8db092e | 46 | '--prefix=DIRECTORY' |
00c1176b | 47 | Install machine-independent data files in subdirectories of |
a8db092e | 48 | 'DIRECTORY'. The default is to install in '/usr/local'. |
00c1176b | 49 | |
a8db092e | 50 | '--exec-prefix=DIRECTORY' |
00c1176b | 51 | Install the library and other machine-dependent files in |
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52 | subdirectories of 'DIRECTORY'. The default is to the '--prefix' |
53 | directory if that option is specified, or '/usr/local' otherwise. | |
00c1176b | 54 | |
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55 | '--with-headers=DIRECTORY' |
56 | Look for kernel header files in DIRECTORY, not '/usr/include'. The | |
57 | GNU C Library needs information from the kernel's header files | |
1f77f049 | 58 | describing the interface to the kernel. The GNU C Library will |
a8db092e | 59 | normally look in '/usr/include' for them, but if you specify this |
1f77f049 | 60 | option, it will look in DIRECTORY instead. |
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61 | |
62 | This option is primarily of use on a system where the headers in | |
a8db092e | 63 | '/usr/include' come from an older version of the GNU C Library. |
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64 | Conflicts can occasionally happen in this case. You can also use |
65 | this option if you want to compile the GNU C Library with a newer | |
a8db092e | 66 | set of kernel headers than the ones found in '/usr/include'. |
41aa20c2 | 67 | |
a8db092e | 68 | '--enable-kernel=VERSION' |
90d1d40b | 69 | This option is currently only useful on GNU/Linux systems. The |
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70 | VERSION parameter should have the form X.Y.Z and describes the |
71 | smallest version of the Linux kernel the generated library is | |
72 | expected to support. The higher the VERSION number is, the less | |
73 | compatibility code is added, and the faster the code gets. | |
74 | ||
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75 | '--with-binutils=DIRECTORY' |
76 | Use the binutils (assembler and linker) in 'DIRECTORY', not the | |
6736e93b | 77 | ones the C compiler would default to. You can use this option if |
41aa20c2 | 78 | the default binutils on your system cannot deal with all the |
a8db092e | 79 | constructs in the GNU C Library. In that case, 'configure' will |
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80 | detect the problem and suppress these constructs, so that the |
81 | library will still be usable, but functionality may be lost--for | |
82 | example, you can't build a shared libc with old binutils. | |
41aa20c2 | 83 | |
a8db092e | 84 | '--disable-shared' |
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85 | Don't build shared libraries even if it is possible. Not all |
86 | systems support shared libraries; you need ELF support and | |
87 | (currently) the GNU linker. | |
41aa20c2 | 88 | |
a8db092e | 89 | '--disable-profile' |
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90 | Don't build libraries with profiling information. You may want to |
91 | use this option if you don't plan to do profiling. | |
41aa20c2 | 92 | |
a8db092e | 93 | '--enable-static-nss' |
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94 | Compile static versions of the NSS (Name Service Switch) libraries. |
95 | This is not recommended because it defeats the purpose of NSS; a | |
96 | program linked statically with the NSS libraries cannot be | |
97 | dynamically reconfigured to use a different name database. | |
98 | ||
a8db092e | 99 | '--enable-hardcoded-path-in-tests' |
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100 | By default, dynamic tests are linked to run with the installed C |
101 | library. This option hardcodes the newly built C library path in | |
102 | dynamic tests so that they can be invoked directly. | |
103 | ||
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104 | '--disable-timezone-tools' |
105 | By default, timezone related utilities ('zic', 'zdump', and | |
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106 | 'tzselect') are installed with the GNU C Library. If you are |
107 | building these independently (e.g. by using the 'tzcode' package), | |
108 | then this option will allow disabling the install of these. | |
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109 | |
110 | Note that you need to make sure the external tools are kept in sync | |
111 | with the versions that the GNU C Library expects as the data | |
112 | formats may change over time. Consult the 'timezone' subdirectory | |
113 | for more details. | |
114 | ||
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115 | '--enable-stack-protector' |
116 | '--enable-stack-protector=strong' | |
117 | '--enable-stack-protector=all' | |
118 | Compile the C library and all other parts of the glibc package | |
119 | (including the threading and math libraries, NSS modules, and | |
120 | transliteration modules) using the GCC '-fstack-protector', | |
121 | '-fstack-protector-strong' or '-fstack-protector-all' options to | |
122 | detect stack overruns. Only the dynamic linker and a small number | |
123 | of routines called directly from assembler are excluded from this | |
124 | protection. | |
125 | ||
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126 | '--enable-bind-now' |
127 | Disable lazy binding for installed shared objects. This provides | |
128 | additional security hardening because it enables full RELRO and a | |
129 | read-only global offset table (GOT), at the cost of slightly | |
130 | increased program load times. | |
131 | ||
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132 | '--enable-pt_chown' |
133 | The file 'pt_chown' is a helper binary for 'grantpt' (*note | |
134 | Pseudo-Terminals: Allocation.) that is installed setuid root to fix | |
135 | up pseudo-terminal ownership. It is not built by default because | |
136 | systems using the Linux kernel are commonly built with the 'devpts' | |
137 | filesystem enabled and mounted at '/dev/pts', which manages | |
138 | pseudo-terminal ownership automatically. By using | |
139 | '--enable-pt_chown', you may build 'pt_chown' and install it setuid | |
140 | and owned by 'root'. The use of 'pt_chown' introduces additional | |
141 | security risks to the system and you should enable it only if you | |
142 | understand and accept those risks. | |
143 | ||
144 | '--disable-werror' | |
145 | By default, the GNU C Library is built with '-Werror'. If you wish | |
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146 | to build without this option (for example, if building with a newer |
147 | version of GCC than this version of the GNU C Library was tested | |
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148 | with, so new warnings cause the build with '-Werror' to fail), you |
149 | can configure with '--disable-werror'. | |
150 | ||
21933112 | 151 | '--disable-mathvec' |
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152 | By default for x86_64, the GNU C Library is built with the vector |
153 | math library. Use this option to disable the vector math library. | |
21933112 | 154 | |
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155 | '--enable-tunables' |
156 | Tunables support allows additional library parameters to be | |
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157 | customized at runtime. This feature is enabled by default. This |
158 | option can take the following values: | |
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159 | |
160 | 'yes' | |
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161 | This is the default if no option is passed to configure. This |
162 | enables tunables and selects the default frontend (currently | |
163 | 'valstring'). | |
164 | ||
165 | 'no' | |
166 | This option disables tunables. | |
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167 | |
168 | 'valstring' | |
169 | This enables tunables and selects the 'valstring' frontend for | |
170 | tunables. This frontend allows users to specify tunables as a | |
171 | colon-separated list in a single environment variable | |
172 | 'GLIBC_TUNABLES'. | |
67e58f39 | 173 | |
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174 | '--enable-obsolete-nsl' |
175 | By default, libnsl is only built as shared library for backward | |
176 | compatibility and the NSS modules libnss_compat, libnss_nis and | |
177 | libnss_nisplus are not built at all. Use this option to enable | |
178 | libnsl with all depending NSS modules and header files. | |
179 | ||
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180 | '--disable-experimental-malloc' |
181 | By default, a per-thread cache is enabled in 'malloc'. While this | |
182 | cache can be disabled on a per-application basis using tunables | |
183 | (set glibc.malloc.tcache_count to zero), this option can be used to | |
184 | remove it from the build completely. | |
185 | ||
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186 | '--build=BUILD-SYSTEM' |
187 | '--host=HOST-SYSTEM' | |
188 | These options are for cross-compiling. If you specify both options | |
189 | and BUILD-SYSTEM is different from HOST-SYSTEM, 'configure' will | |
190 | prepare to cross-compile the GNU C Library from BUILD-SYSTEM to be | |
191 | used on HOST-SYSTEM. You'll probably need the '--with-headers' | |
192 | option too, and you may have to override CONFIGURE's selection of | |
193 | the compiler and/or binutils. | |
194 | ||
195 | If you only specify '--host', 'configure' will prepare for a native | |
196 | compile but use what you specify instead of guessing what your | |
197 | system is. This is most useful to change the CPU submodel. For | |
198 | example, if 'configure' guesses your machine as 'i686-pc-linux-gnu' | |
199 | but you want to compile a library for 586es, give | |
200 | '--host=i586-pc-linux-gnu' or just '--host=i586-linux' and add the | |
201 | appropriate compiler flags ('-mcpu=i586' will do the trick) to | |
ad1b5f19 | 202 | CFLAGS. |
1792d4db | 203 | |
a8db092e | 204 | If you specify just '--build', 'configure' will get confused. |
41aa20c2 | 205 | |
a8db092e | 206 | '--with-pkgversion=VERSION' |
8b748aed | 207 | Specify a description, possibly including a build number or build |
a8db092e | 208 | date, of the binaries being built, to be included in '--version' |
8b748aed | 209 | output from programs installed with the GNU C Library. For |
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210 | example, '--with-pkgversion='FooBar GNU/Linux glibc build 123''. |
211 | The default value is 'GNU libc'. | |
8b748aed | 212 | |
a8db092e | 213 | '--with-bugurl=URL' |
8b748aed | 214 | Specify the URL that users should visit if they wish to report a |
a8db092e | 215 | bug, to be included in '--help' output from programs installed with |
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216 | the GNU C Library. The default value refers to the main |
217 | bug-reporting information for the GNU C Library. | |
218 | ||
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219 | To build the library and related programs, type 'make'. This will |
220 | produce a lot of output, some of which may look like errors from 'make' | |
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221 | but aren't. Look for error messages from 'make' containing '***'. |
222 | Those indicate that something is seriously wrong. | |
41aa20c2 | 223 | |
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224 | The compilation process can take a long time, depending on the |
225 | configuration and the speed of your machine. Some complex modules may | |
226 | take a very long time to compile, as much as several minutes on slower | |
227 | machines. Do not panic if the compiler appears to hang. | |
00c1176b | 228 | |
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229 | If you want to run a parallel make, simply pass the '-j' option with |
230 | an appropriate numeric parameter to 'make'. You need a recent GNU | |
231 | 'make' version, though. | |
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232 | |
233 | To build and run test programs which exercise some of the library | |
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234 | facilities, type 'make check'. If it does not complete successfully, do |
235 | not use the built library, and report a bug after verifying that the | |
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236 | problem is not already known. *Note Reporting Bugs::, for instructions |
237 | on reporting bugs. Note that some of the tests assume they are not | |
a8db092e | 238 | being run by 'root'. We recommend you compile and test the GNU C |
1f77f049 | 239 | Library as an unprivileged user. |
41aa20c2 | 240 | |
8d4b5a8a | 241 | Before reporting bugs make sure there is no problem with your system. |
6736e93b | 242 | The tests (and later installation) use some pre-existing files of the |
a8db092e | 243 | system such as '/etc/passwd', '/etc/nsswitch.conf' and others. These |
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244 | files must all contain correct and sensible content. |
245 | ||
a8db092e | 246 | Normally, 'make check' will run all the tests before reporting all |
d6fe5e58 | 247 | problems found and exiting with error status if any problems occurred. |
a8db092e | 248 | You can specify 'stop-on-test-failure=y' when running 'make check' to |
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249 | make the test run stop and exit with an error status immediately when a |
250 | failure occurs. | |
251 | ||
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252 | The GNU C Library pretty printers come with their own set of scripts |
253 | for testing, which run together with the rest of the testsuite through | |
254 | 'make check'. These scripts require the following tools to run | |
255 | successfully: | |
256 | ||
257 | * Python 2.7.6/3.4.3 or later | |
258 | ||
259 | Python is required for running the printers' test scripts. | |
260 | ||
261 | * PExpect 4.0 | |
262 | ||
263 | The printer tests drive GDB through test programs and compare its | |
264 | output to the printers'. PExpect is used to capture the output of | |
265 | GDB, and should be compatible with the Python version in your | |
266 | system. | |
267 | ||
268 | * GDB 7.8 or later with support for Python 2.7.6/3.4.3 or later | |
269 | ||
270 | GDB itself needs to be configured with Python support in order to | |
271 | use the pretty printers. Notice that your system having Python | |
272 | available doesn't imply that GDB supports it, nor that your | |
273 | system's Python and GDB's have the same version. | |
274 | ||
275 | If these tools are absent, the printer tests will report themselves as | |
276 | 'UNSUPPORTED'. Notice that some of the printer tests require the GNU C | |
277 | Library to be compiled with debugging symbols. | |
278 | ||
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279 | To format the 'GNU C Library Reference Manual' for printing, type |
280 | 'make dvi'. You need a working TeX installation to do this. The | |
281 | distribution builds the on-line formatted version of the manual, as Info | |
282 | files, as part of the build process. You can build them manually with | |
283 | 'make info'. | |
1792d4db | 284 | |
c0389ee4 | 285 | The library has a number of special-purpose configuration parameters |
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286 | which you can find in 'Makeconfig'. These can be overwritten with the |
287 | file 'configparms'. To change them, create a 'configparms' in your | |
288 | build directory and add values as appropriate for your system. The file | |
289 | is included and parsed by 'make' and has to follow the conventions for | |
290 | makefiles. | |
c0389ee4 | 291 | |
1f77f049 | 292 | It is easy to configure the GNU C Library for cross-compilation by |
a8db092e | 293 | setting a few variables in 'configparms'. Set 'CC' to the |
c0389ee4 | 294 | cross-compiler for the target you configured the library for; it is |
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295 | important to use this same 'CC' value when running 'configure', like |
296 | this: 'CC=TARGET-gcc configure TARGET'. Set 'BUILD_CC' to the compiler | |
6736e93b | 297 | to use for programs run on the build system as part of compiling the |
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298 | library. You may need to set 'AR' to cross-compiling versions of 'ar' |
299 | if the native tools are not configured to work with object files for the | |
300 | target you configured for. When cross-compiling the GNU C Library, it | |
301 | may be tested using 'make check | |
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302 | test-wrapper="SRCDIR/scripts/cross-test-ssh.sh HOSTNAME"', where SRCDIR |
303 | is the absolute directory name for the main source directory and | |
304 | HOSTNAME is the host name of a system that can run the newly built | |
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305 | binaries of the GNU C Library. The source and build directories must be |
306 | visible at the same locations on both the build system and HOSTNAME. | |
c0389ee4 | 307 | |
a8db092e | 308 | In general, when testing the GNU C Library, 'test-wrapper' may be set |
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309 | to the name and arguments of any program to run newly built binaries. |
310 | This program must preserve the arguments to the binary being run, its | |
8540f6d2 | 311 | working directory and the standard input, output and error file |
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312 | descriptors. If 'TEST-WRAPPER env' will not work to run a program with |
313 | environment variables set, then 'test-wrapper-env' must be set to a | |
8540f6d2 | 314 | program that runs a newly built program with environment variable |
a8db092e | 315 | assignments in effect, those assignments being specified as 'VAR=VALUE' |
8540f6d2 | 316 | before the name of the program to be run. If multiple assignments to |
a8db092e | 317 | the same variable are specified, the last assignment specified must take |
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318 | precedence. Similarly, if 'TEST-WRAPPER env -i' will not work to run a |
319 | program with an environment completely empty of variables except those | |
320 | directly assigned, then 'test-wrapper-env-only' must be set; its use has | |
321 | the same syntax as 'test-wrapper-env', the only difference in its | |
322 | semantics being starting with an empty set of environment variables | |
323 | rather than the ambient set. | |
0eb69512 | 324 | |
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325 | Installing the C Library |
326 | ======================== | |
41aa20c2 | 327 | |
80ed68b7 | 328 | To install the library and its header files, and the Info files of the |
a8db092e | 329 | manual, type 'make install'. This will build things, if necessary, |
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330 | before installing them; however, you should still compile everything |
331 | first. If you are installing the GNU C Library as your primary C | |
332 | library, we recommend that you shut the system down to single-user mode | |
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333 | first, and reboot afterward. This minimizes the risk of breaking things |
334 | when the library changes out from underneath. | |
1792d4db | 335 | |
a8db092e | 336 | 'make install' will do the entire job of upgrading from a previous |
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337 | installation of the GNU C Library version 2.x. There may sometimes be |
338 | headers left behind from the previous installation, but those are | |
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339 | generally harmless. If you want to avoid leaving headers behind you can |
340 | do things in the following order. | |
c0389ee4 | 341 | |
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342 | You must first build the library ('make'), optionally check it ('make |
343 | check'), switch the include directories and then install ('make | |
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344 | install'). The steps must be done in this order. Not moving the |
345 | directory before install will result in an unusable mixture of header | |
346 | files from both libraries, but configuring, building, and checking the | |
347 | library requires the ability to compile and run programs against the old | |
a8db092e | 348 | library. The new '/usr/include', after switching the include |
02c4bbad | 349 | directories and before installing the library should contain the Linux |
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350 | headers, but nothing else. If you do this, you will need to restore any |
351 | headers from libraries other than the GNU C Library yourself after | |
1f77f049 | 352 | installing the library. |
c0389ee4 | 353 | |
1f77f049 | 354 | You can install the GNU C Library somewhere other than where you |
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355 | configured it to go by setting the 'DESTDIR' GNU standard make variable |
356 | on the command line for 'make install'. The value of this variable is | |
1f77f049 | 357 | prepended to all the paths for installation. This is useful when |
a8db092e | 358 | setting up a chroot environment or preparing a binary distribution. The |
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359 | directory should be specified with an absolute file name. Installing |
360 | with the 'prefix' and 'exec_prefix' GNU standard make variables set is | |
361 | not supported. | |
1792d4db | 362 | |
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363 | The GNU C Library includes a daemon called 'nscd', which you may or |
364 | may not want to run. 'nscd' caches name service lookups; it can | |
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365 | dramatically improve performance with NIS+, and may help with DNS as |
366 | well. | |
1792d4db | 367 | |
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368 | One auxiliary program, '/usr/libexec/pt_chown', is installed setuid |
369 | 'root' if the '--enable-pt_chown' configuration option is used. This | |
370 | program is invoked by the 'grantpt' function; it sets the permissions on | |
371 | a pseudoterminal so it can be used by the calling process. If you are | |
372 | using a Linux kernel with the 'devpts' filesystem enabled and mounted at | |
373 | '/dev/pts', you don't need this program. | |
41aa20c2 | 374 | |
bd952512 | 375 | After installation you might want to configure the timezone and |
1f77f049 | 376 | locale installation of your system. The GNU C Library comes with a |
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377 | locale database which gets configured with 'localedef'. For example, to |
378 | set up a German locale with name 'de_DE', simply issue the command | |
379 | 'localedef -i de_DE -f ISO-8859-1 de_DE'. To configure all locales that | |
380 | are supported by the GNU C Library, you can issue from your build | |
381 | directory the command 'make localedata/install-locales'. | |
382 | ||
383 | To configure the locally used timezone, set the 'TZ' environment | |
384 | variable. The script 'tzselect' helps you to select the right value. | |
385 | As an example, for Germany, 'tzselect' would tell you to use | |
386 | 'TZ='Europe/Berlin''. For a system wide installation (the given paths | |
387 | are for an installation with '--prefix=/usr'), link the timezone file | |
388 | which is in '/usr/share/zoneinfo' to the file '/etc/localtime'. For | |
389 | Germany, you might execute 'ln -s /usr/share/zoneinfo/Europe/Berlin | |
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390 | /etc/localtime'. |
391 | ||
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392 | Recommended Tools for Compilation |
393 | ================================= | |
41aa20c2 | 394 | |
80ed68b7 | 395 | We recommend installing the following GNU tools before attempting to |
1f77f049 | 396 | build the GNU C Library: |
41aa20c2 | 397 | |
a8db092e | 398 | * GNU 'make' 3.79 or newer |
41aa20c2 | 399 | |
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400 | You need the latest version of GNU 'make'. Modifying the GNU C |
401 | Library to work with other 'make' programs would be so difficult | |
402 | that we recommend you port GNU 'make' instead. *Really.* We | |
403 | recommend GNU 'make' version 3.79. All earlier versions have | |
6736e93b | 404 | severe bugs or lack features. |
41aa20c2 | 405 | |
4add8674 | 406 | * GCC 4.9 or newer |
0e7727f7 | 407 | |
4add8674 | 408 | GCC 4.9 or higher is required. In general it is recommended to use |
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409 | the newest version of the compiler that is known to work for |
410 | building the GNU C Library, as newer compilers usually produce | |
15192aaa | 411 | better code. As of release time, GCC 7.1 is the newest compiler |
4863355a | 412 | verified to work to build the GNU C Library. |
91ea72b7 | 413 | |
4efe3ce4 GG |
414 | For PowerPC 64-bits little-endian (powerpc64le), GCC 6.2 or higher |
415 | is required. This compiler version is the first to provide the | |
416 | features required for building the GNU C Library with support for | |
417 | '_Float128'. | |
418 | ||
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419 | For multi-arch support it is recommended to use a GCC which has |
420 | been built with support for GNU indirect functions. This ensures | |
421 | that correct debugging information is generated for functions | |
422 | selected by IFUNC resolvers. This support can either be enabled by | |
423 | configuring GCC with '--enable-gnu-indirect-function', or by | |
424 | enabling it by default by setting 'default_gnu_indirect_function' | |
425 | variable for a particular architecture in the GCC source file | |
426 | 'gcc/config.gcc'. | |
427 | ||
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428 | You can use whatever compiler you like to compile programs that use |
429 | the GNU C Library. | |
41aa20c2 | 430 | |
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431 | Check the FAQ for any special compiler issues on particular |
432 | platforms. | |
5713a71e | 433 | |
073e8fa7 | 434 | * GNU 'binutils' 2.25 or later |
41aa20c2 | 435 | |
a8db092e | 436 | You must use GNU 'binutils' (as and ld) to build the GNU C Library. |
7a49a7d5 | 437 | No other assembler or linker has the necessary functionality at the |
15192aaa | 438 | moment. As of release time, GNU 'binutils' 2.27 is the newest |
04cb913d | 439 | verified to work to build the GNU C Library. |
41aa20c2 | 440 | |
a8db092e | 441 | * GNU 'texinfo' 4.7 or later |
41aa20c2 UD |
442 | |
443 | To correctly translate and install the Texinfo documentation you | |
a8db092e | 444 | need this version of the 'texinfo' package. Earlier versions do |
41aa20c2 | 445 | not understand all the tags used in the document, and the |
1792d4db | 446 | installation mechanism for the info files is not present or works |
2c8f75f7 | 447 | differently. As of release time, 'texinfo' 6.0 is the newest |
04cb913d | 448 | verified to work to build the GNU C Library. |
41aa20c2 | 449 | |
a8db092e | 450 | * GNU 'awk' 3.1.2, or higher |
00c1176b | 451 | |
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452 | 'awk' is used in several places to generate files. Some 'gawk' |
453 | extensions are used, including the 'asorti' function, which was | |
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454 | introduced in version 3.1.2 of 'gawk'. As of release time, 'gawk' |
455 | version 4.1.3 is the newest verified to work to build the GNU C | |
456 | Library. | |
41aa20c2 | 457 | |
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458 | * GNU 'bison' 2.7 or later |
459 | ||
460 | 'bison' is used to generate the 'yacc' parser code in the 'intl' | |
461 | subdirectory. | |
462 | ||
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463 | * Perl 5 |
464 | ||
465 | Perl is not required, but it is used if present to test the | |
466 | installation. We may decide to use it elsewhere in the future. | |
41aa20c2 | 467 | |
a8db092e | 468 | * GNU 'sed' 3.02 or newer |
c0389ee4 | 469 | |
a8db092e | 470 | 'Sed' is used in several places to generate files. Most scripts |
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471 | work with any version of 'sed'. As of release time, 'sed' version |
472 | 4.2.2 is the newest verified to work to build the GNU C Library. | |
c0389ee4 | 473 | |
a8db092e | 474 | If you change any of the 'configure.ac' files you will also need |
0cc70fcf | 475 | |
a8db092e | 476 | * GNU 'autoconf' 2.69 (exactly) |
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477 | |
478 | and if you change any of the message translation files you will need | |
479 | ||
a8db092e | 480 | * GNU 'gettext' 0.10.36 or later |
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481 | |
482 | You may also need these packages if you upgrade your source tree using | |
483 | patches, although we try to avoid this. | |
484 | ||
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485 | Specific advice for GNU/Linux systems |
486 | ===================================== | |
80ed68b7 | 487 | |
a7a93d50 | 488 | If you are installing the GNU C Library on GNU/Linux systems, you need |
5b4ecd3f | 489 | to have the header files from a 3.2 or newer kernel around for |
e9203023 FW |
490 | reference. (For the ia64 architecture, you need version 3.2.18 or newer |
491 | because this is the first version with support for the 'accept4' system | |
492 | call.) These headers must be installed using 'make headers_install'; | |
493 | the headers present in the kernel source directory are not suitable for | |
494 | direct use by the GNU C Library. You do not need to use that kernel, | |
495 | just have its headers installed where the GNU C Library can access them, | |
496 | referred to here as INSTALL-DIRECTORY. The easiest way to do this is to | |
497 | unpack it in a directory such as '/usr/src/linux-VERSION'. In that | |
498 | directory, run 'make headers_install | |
1f77f049 | 499 | INSTALL_HDR_PATH=INSTALL-DIRECTORY'. Finally, configure the GNU C |
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500 | Library with the option '--with-headers=INSTALL-DIRECTORY/include'. Use |
501 | the most recent kernel you can get your hands on. (If you are | |
1f77f049 | 502 | cross-compiling the GNU C Library, you need to specify |
a8db092e | 503 | 'ARCH=ARCHITECTURE' in the 'make headers_install' command, where |
1f77f049 | 504 | ARCHITECTURE is the architecture name used by the Linux kernel, such as |
a8db092e | 505 | 'x86' or 'powerpc'.) |
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506 | |
507 | After installing the GNU C Library, you may need to remove or rename | |
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508 | directories such as '/usr/include/linux' and '/usr/include/asm', and |
509 | replace them with copies of directories such as 'linux' and 'asm' from | |
510 | 'INSTALL-DIRECTORY/include'. All directories present in | |
511 | 'INSTALL-DIRECTORY/include' should be copied, except that the GNU C | |
512 | Library provides its own version of '/usr/include/scsi'; the files | |
513 | provided by the kernel should be copied without replacing those provided | |
514 | by the GNU C Library. The 'linux', 'asm' and 'asm-generic' directories | |
515 | are required to compile programs using the GNU C Library; the other | |
516 | directories describe interfaces to the kernel but are not required if | |
517 | not compiling programs using those interfaces. You do not need to copy | |
518 | kernel headers if you did not specify an alternate kernel header source | |
519 | using '--with-headers'. | |
1f77f049 | 520 | |
a7a93d50 | 521 | The Filesystem Hierarchy Standard for GNU/Linux systems expects some |
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522 | components of the GNU C Library installation to be in '/lib' and some in |
523 | '/usr/lib'. This is handled automatically if you configure the GNU C | |
524 | Library with '--prefix=/usr'. If you set some other prefix or allow it | |
525 | to default to '/usr/local', then all the components are installed there. | |
1792d4db | 526 | |
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527 | Reporting Bugs |
528 | ============== | |
41aa20c2 | 529 | |
1f77f049 | 530 | There are probably bugs in the GNU C Library. There are certainly |
41aa20c2 UD |
531 | errors and omissions in this manual. If you report them, they will get |
532 | fixed. If you don't, no one will ever know about them and they will | |
533 | remain unfixed for all eternity, if not longer. | |
534 | ||
bd952512 | 535 | It is a good idea to verify that the problem has not already been |
a8db092e | 536 | reported. Bugs are documented in two places: The file 'BUGS' describes |
8b748aed | 537 | a number of well known bugs and the central GNU C Library bug tracking |
a306c790 | 538 | system has a WWW interface at <https://sourceware.org/bugzilla/>. The |
8b748aed JM |
539 | WWW interface gives you access to open and closed reports. A closed |
540 | report normally includes a patch or a hint on solving the problem. | |
6736e93b | 541 | |
a8db092e CD |
542 | To report a bug, first you must find it. With any luck, this will be |
543 | the hard part. Once you've found a bug, make sure it's really a bug. A | |
544 | good way to do this is to see if the GNU C Library behaves the same way | |
545 | some other C library does. If so, probably you are wrong and the | |
546 | libraries are right (but not necessarily). If not, one of the libraries | |
547 | is probably wrong. It might not be the GNU C Library. Many historical | |
548 | Unix C libraries permit things that we don't, such as closing a file | |
549 | twice. | |
1792d4db | 550 | |
1f77f049 | 551 | If you think you have found some way in which the GNU C Library does |
1792d4db | 552 | not conform to the ISO and POSIX standards (*note Standards and |
c0389ee4 | 553 | Portability::), that is definitely a bug. Report it! |
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554 | |
555 | Once you're sure you've found a bug, try to narrow it down to the | |
556 | smallest test case that reproduces the problem. In the case of a C | |
557 | library, you really only need to narrow it down to one library function | |
558 | call, if possible. This should not be too difficult. | |
559 | ||
560 | The final step when you have a simple test case is to report the bug. | |
a8db092e | 561 | Do this at <http://www.gnu.org/software/libc/bugs.html>. |
41aa20c2 UD |
562 | |
563 | If you are not sure how a function should behave, and this manual | |
564 | doesn't tell you, that's a bug in the manual. Report that too! If the | |
565 | function's behavior disagrees with the manual, then either the library | |
566 | or the manual has a bug, so report the disagreement. If you find any | |
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567 | errors or omissions in this manual, please report them to the bug |
568 | database. If you refer to specific sections of the manual, please | |
569 | include the section names for easier identification. |