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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 | <http://sourceware.org/glibc/wiki/FAQ>. It answers common questions and |
6 | describes problems you may experience with compilation and installation. | |
41aa20c2 | 7 | |
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8 | Features can be added to the GNU C Library via "add-on" bundles. |
9 | These are separate tar files, which you unpack into the top level of the | |
10 | source tree. Then you give 'configure' the '--enable-add-ons' option to | |
11 | activate them, and they will be compiled into the library. | |
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12 | |
13 | You will need recent versions of several GNU tools: definitely GCC | |
fe959e1e | 14 | and GNU Make, and possibly others. *Note Tools for Compilation::, |
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15 | below. |
16 | ||
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17 | Configuring and compiling the GNU C Library |
18 | =========================================== | |
00c1176b | 19 | |
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20 | The GNU C Library cannot be compiled in the source directory. You must |
21 | build it in a separate build directory. For example, if you have | |
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22 | unpacked the GNU C Library sources in '/src/gnu/glibc-VERSION', create a |
23 | directory '/src/gnu/glibc-build' to put the object files in. This | |
24 | allows removing the whole build directory in case an error occurs, which | |
25 | is the safest way to get a fresh start and should always be done. | |
00c1176b | 26 | |
a8db092e | 27 | From your object directory, run the shell script 'configure' located |
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28 | at the top level of the source tree. In the scenario above, you'd type |
29 | ||
f1e86fca | 30 | $ ../glibc-VERSION/configure ARGS... |
00c1176b | 31 | |
3858bf28 | 32 | Please note that even though you're building in a separate build |
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33 | directory, the compilation may need to create or modify files and |
34 | directories in the source directory. | |
f05f5ca3 | 35 | |
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36 | 'configure' takes many options, but the only one that is usually |
37 | mandatory is '--prefix'. This option tells 'configure' where you want | |
38 | the GNU C Library installed. This defaults to '/usr/local', but the | |
1f77f049 | 39 | normal setting to install as the standard system library is |
a8db092e | 40 | '--prefix=/usr' for GNU/Linux systems and '--prefix=' (an empty prefix) |
1f77f049 | 41 | for GNU/Hurd systems. |
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42 | |
43 | It may also be useful to set the CC and CFLAGS variables in the | |
a8db092e | 44 | environment when running 'configure'. CC selects the C compiler that |
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45 | will be used, and CFLAGS sets optimization options for the compiler. |
46 | ||
bd952512 | 47 | The following list describes all of the available options for |
a8db092e | 48 | 'configure': |
00c1176b | 49 | |
a8db092e | 50 | '--prefix=DIRECTORY' |
00c1176b | 51 | Install machine-independent data files in subdirectories of |
a8db092e | 52 | 'DIRECTORY'. The default is to install in '/usr/local'. |
00c1176b | 53 | |
a8db092e | 54 | '--exec-prefix=DIRECTORY' |
00c1176b | 55 | Install the library and other machine-dependent files in |
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56 | subdirectories of 'DIRECTORY'. The default is to the '--prefix' |
57 | directory if that option is specified, or '/usr/local' otherwise. | |
00c1176b | 58 | |
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59 | '--with-headers=DIRECTORY' |
60 | Look for kernel header files in DIRECTORY, not '/usr/include'. The | |
61 | GNU C Library needs information from the kernel's header files | |
1f77f049 | 62 | describing the interface to the kernel. The GNU C Library will |
a8db092e | 63 | normally look in '/usr/include' for them, but if you specify this |
1f77f049 | 64 | option, it will look in DIRECTORY instead. |
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65 | |
66 | This option is primarily of use on a system where the headers in | |
a8db092e | 67 | '/usr/include' come from an older version of the GNU C Library. |
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68 | Conflicts can occasionally happen in this case. You can also use |
69 | this option if you want to compile the GNU C Library with a newer | |
a8db092e | 70 | set of kernel headers than the ones found in '/usr/include'. |
41aa20c2 | 71 | |
a8db092e | 72 | '--enable-add-ons[=LIST]' |
3858bf28 | 73 | Specify add-on packages to include in the build. If this option is |
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74 | specified with no list, it enables all the add-on packages it finds |
75 | in the main source directory; this is the default behavior. You | |
76 | may specify an explicit list of add-ons to use in LIST, separated | |
77 | by spaces or commas (if you use spaces, remember to quote them from | |
78 | the shell). Each add-on in LIST can be an absolute directory name | |
79 | or can be a directory name relative to the main source directory, | |
80 | or relative to the build directory (that is, the current working | |
81 | directory). For example, | |
82 | '--enable-add-ons=nptl,../glibc-libidn-VERSION'. | |
83 | ||
84 | '--enable-kernel=VERSION' | |
90d1d40b | 85 | This option is currently only useful on GNU/Linux systems. The |
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86 | VERSION parameter should have the form X.Y.Z and describes the |
87 | smallest version of the Linux kernel the generated library is | |
88 | expected to support. The higher the VERSION number is, the less | |
89 | compatibility code is added, and the faster the code gets. | |
90 | ||
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91 | '--with-binutils=DIRECTORY' |
92 | Use the binutils (assembler and linker) in 'DIRECTORY', not the | |
6736e93b | 93 | ones the C compiler would default to. You can use this option if |
41aa20c2 | 94 | the default binutils on your system cannot deal with all the |
a8db092e | 95 | constructs in the GNU C Library. In that case, 'configure' will |
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96 | detect the problem and suppress these constructs, so that the |
97 | library will still be usable, but functionality may be lost--for | |
98 | example, you can't build a shared libc with old binutils. | |
41aa20c2 | 99 | |
a8db092e | 100 | '--without-fp' |
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101 | Use this option if your computer lacks hardware floating-point |
102 | support and your operating system does not emulate an FPU. | |
103 | ||
a8db092e | 104 | '--disable-shared' |
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105 | Don't build shared libraries even if it is possible. Not all |
106 | systems support shared libraries; you need ELF support and | |
107 | (currently) the GNU linker. | |
41aa20c2 | 108 | |
a8db092e | 109 | '--disable-profile' |
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110 | Don't build libraries with profiling information. You may want to |
111 | use this option if you don't plan to do profiling. | |
41aa20c2 | 112 | |
a8db092e | 113 | '--enable-static-nss' |
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114 | Compile static versions of the NSS (Name Service Switch) libraries. |
115 | This is not recommended because it defeats the purpose of NSS; a | |
116 | program linked statically with the NSS libraries cannot be | |
117 | dynamically reconfigured to use a different name database. | |
118 | ||
a8db092e | 119 | '--without-tls' |
6736e93b | 120 | By default the C library is built with support for thread-local |
a8db092e | 121 | storage if the used tools support it. By using '--without-tls' |
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122 | this can be prevented though there generally is no reason since it |
123 | creates compatibility problems. | |
124 | ||
a8db092e | 125 | '--enable-hardcoded-path-in-tests' |
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126 | By default, dynamic tests are linked to run with the installed C |
127 | library. This option hardcodes the newly built C library path in | |
128 | dynamic tests so that they can be invoked directly. | |
129 | ||
a8db092e | 130 | '--enable-lock-elision=yes' |
52dfbe13 | 131 | Enable lock elision for pthread mutexes by default. |
1717da59 | 132 | |
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133 | '--enable-pt_chown' |
134 | The file 'pt_chown' is a helper binary for 'grantpt' (*note | |
135 | Pseudo-Terminals: Allocation.) that is installed setuid root to fix | |
136 | up pseudo-terminal ownership. It is not built by default because | |
137 | systems using the Linux kernel are commonly built with the 'devpts' | |
138 | filesystem enabled and mounted at '/dev/pts', which manages | |
139 | pseudo-terminal ownership automatically. By using | |
140 | '--enable-pt_chown', you may build 'pt_chown' and install it setuid | |
141 | and owned by 'root'. The use of 'pt_chown' introduces additional | |
142 | security risks to the system and you should enable it only if you | |
143 | understand and accept those risks. | |
144 | ||
145 | '--disable-werror' | |
146 | By default, the GNU C Library is built with '-Werror'. If you wish | |
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147 | to build without this option (for example, if building with a newer |
148 | version of GCC than this version of the GNU C Library was tested | |
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149 | with, so new warnings cause the build with '-Werror' to fail), you |
150 | can configure with '--disable-werror'. | |
151 | ||
152 | '--build=BUILD-SYSTEM' | |
153 | '--host=HOST-SYSTEM' | |
154 | These options are for cross-compiling. If you specify both options | |
155 | and BUILD-SYSTEM is different from HOST-SYSTEM, 'configure' will | |
156 | prepare to cross-compile the GNU C Library from BUILD-SYSTEM to be | |
157 | used on HOST-SYSTEM. You'll probably need the '--with-headers' | |
158 | option too, and you may have to override CONFIGURE's selection of | |
159 | the compiler and/or binutils. | |
160 | ||
161 | If you only specify '--host', 'configure' will prepare for a native | |
162 | compile but use what you specify instead of guessing what your | |
163 | system is. This is most useful to change the CPU submodel. For | |
164 | example, if 'configure' guesses your machine as 'i686-pc-linux-gnu' | |
165 | but you want to compile a library for 586es, give | |
166 | '--host=i586-pc-linux-gnu' or just '--host=i586-linux' and add the | |
167 | appropriate compiler flags ('-mcpu=i586' will do the trick) to | |
ad1b5f19 | 168 | CFLAGS. |
1792d4db | 169 | |
a8db092e | 170 | If you specify just '--build', 'configure' will get confused. |
41aa20c2 | 171 | |
a8db092e | 172 | '--with-pkgversion=VERSION' |
8b748aed | 173 | Specify a description, possibly including a build number or build |
a8db092e | 174 | date, of the binaries being built, to be included in '--version' |
8b748aed | 175 | output from programs installed with the GNU C Library. For |
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176 | example, '--with-pkgversion='FooBar GNU/Linux glibc build 123''. |
177 | The default value is 'GNU libc'. | |
8b748aed | 178 | |
a8db092e | 179 | '--with-bugurl=URL' |
8b748aed | 180 | Specify the URL that users should visit if they wish to report a |
a8db092e | 181 | bug, to be included in '--help' output from programs installed with |
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182 | the GNU C Library. The default value refers to the main |
183 | bug-reporting information for the GNU C Library. | |
184 | ||
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185 | To build the library and related programs, type 'make'. This will |
186 | produce a lot of output, some of which may look like errors from 'make' | |
187 | but isn't. Look for error messages from 'make' containing '***'. Those | |
188 | indicate that something is seriously wrong. | |
41aa20c2 | 189 | |
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190 | The compilation process can take a long time, depending on the |
191 | configuration and the speed of your machine. Some complex modules may | |
192 | take a very long time to compile, as much as several minutes on slower | |
193 | machines. Do not panic if the compiler appears to hang. | |
00c1176b | 194 | |
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195 | If you want to run a parallel make, simply pass the '-j' option with |
196 | an appropriate numeric parameter to 'make'. You need a recent GNU | |
197 | 'make' version, though. | |
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198 | |
199 | To build and run test programs which exercise some of the library | |
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200 | facilities, type 'make check'. If it does not complete successfully, do |
201 | not use the built library, and report a bug after verifying that the | |
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202 | problem is not already known. *Note Reporting Bugs::, for instructions |
203 | on reporting bugs. Note that some of the tests assume they are not | |
a8db092e | 204 | being run by 'root'. We recommend you compile and test the GNU C |
1f77f049 | 205 | Library as an unprivileged user. |
41aa20c2 | 206 | |
8d4b5a8a | 207 | Before reporting bugs make sure there is no problem with your system. |
6736e93b | 208 | The tests (and later installation) use some pre-existing files of the |
a8db092e | 209 | system such as '/etc/passwd', '/etc/nsswitch.conf' and others. These |
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210 | files must all contain correct and sensible content. |
211 | ||
a8db092e | 212 | Normally, 'make check' will run all the tests before reporting all |
d6fe5e58 | 213 | problems found and exiting with error status if any problems occurred. |
a8db092e | 214 | You can specify 'stop-on-test-failure=y' when running 'make check' to |
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215 | make the test run stop and exit with an error status immediately when a |
216 | failure occurs. | |
217 | ||
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218 | To format the 'GNU C Library Reference Manual' for printing, type |
219 | 'make dvi'. You need a working TeX installation to do this. The | |
220 | distribution builds the on-line formatted version of the manual, as Info | |
221 | files, as part of the build process. You can build them manually with | |
222 | 'make info'. | |
1792d4db | 223 | |
c0389ee4 | 224 | The library has a number of special-purpose configuration parameters |
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225 | which you can find in 'Makeconfig'. These can be overwritten with the |
226 | file 'configparms'. To change them, create a 'configparms' in your | |
227 | build directory and add values as appropriate for your system. The file | |
228 | is included and parsed by 'make' and has to follow the conventions for | |
229 | makefiles. | |
c0389ee4 | 230 | |
1f77f049 | 231 | It is easy to configure the GNU C Library for cross-compilation by |
a8db092e | 232 | setting a few variables in 'configparms'. Set 'CC' to the |
c0389ee4 | 233 | cross-compiler for the target you configured the library for; it is |
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234 | important to use this same 'CC' value when running 'configure', like |
235 | this: 'CC=TARGET-gcc configure TARGET'. Set 'BUILD_CC' to the compiler | |
6736e93b | 236 | to use for programs run on the build system as part of compiling the |
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237 | library. You may need to set 'AR' to cross-compiling versions of 'ar' |
238 | if the native tools are not configured to work with object files for the | |
239 | target you configured for. When cross-compiling the GNU C Library, it | |
240 | may be tested using 'make check | |
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241 | test-wrapper="SRCDIR/scripts/cross-test-ssh.sh HOSTNAME"', where SRCDIR |
242 | is the absolute directory name for the main source directory and | |
243 | HOSTNAME is the host name of a system that can run the newly built | |
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244 | binaries of the GNU C Library. The source and build directories must be |
245 | visible at the same locations on both the build system and HOSTNAME. | |
c0389ee4 | 246 | |
a8db092e | 247 | In general, when testing the GNU C Library, 'test-wrapper' may be set |
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248 | to the name and arguments of any program to run newly built binaries. |
249 | This program must preserve the arguments to the binary being run, its | |
8540f6d2 | 250 | working directory and the standard input, output and error file |
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251 | descriptors. If 'TEST-WRAPPER env' will not work to run a program with |
252 | environment variables set, then 'test-wrapper-env' must be set to a | |
8540f6d2 | 253 | program that runs a newly built program with environment variable |
a8db092e | 254 | assignments in effect, those assignments being specified as 'VAR=VALUE' |
8540f6d2 | 255 | before the name of the program to be run. If multiple assignments to |
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256 | the same variable are specified, the last assignment specified must take |
257 | precedence. | |
0eb69512 | 258 | |
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259 | Installing the C Library |
260 | ======================== | |
41aa20c2 | 261 | |
80ed68b7 | 262 | To install the library and its header files, and the Info files of the |
a8db092e | 263 | manual, type 'make install'. This will build things, if necessary, |
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264 | before installing them; however, you should still compile everything |
265 | first. If you are installing the GNU C Library as your primary C | |
266 | library, we recommend that you shut the system down to single-user mode | |
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267 | first, and reboot afterward. This minimizes the risk of breaking things |
268 | when the library changes out from underneath. | |
1792d4db | 269 | |
a8db092e | 270 | 'make install' will do the entire job of upgrading from a previous |
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271 | installation of the GNU C Library version 2.x. There may sometimes be |
272 | headers left behind from the previous installation, but those are | |
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273 | generally harmless. If you want to avoid leaving headers behind you can |
274 | do things in the following order. | |
c0389ee4 | 275 | |
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276 | You must first build the library ('make'), optionally check it ('make |
277 | check'), switch the include directories and then install ('make | |
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278 | install'). The steps must be done in this order. Not moving the |
279 | directory before install will result in an unusable mixture of header | |
280 | files from both libraries, but configuring, building, and checking the | |
281 | library requires the ability to compile and run programs against the old | |
a8db092e | 282 | library. The new '/usr/include', after switching the include |
02c4bbad | 283 | directories and before installing the library should contain the Linux |
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284 | headers, but nothing else. If you do this, you will need to restore any |
285 | headers from libraries other than the GNU C Library yourself after | |
1f77f049 | 286 | installing the library. |
c0389ee4 | 287 | |
1f77f049 | 288 | You can install the GNU C Library somewhere other than where you |
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289 | configured it to go by setting the 'install_root' variable on the |
290 | command line for 'make install'. The value of this variable is | |
1f77f049 | 291 | prepended to all the paths for installation. This is useful when |
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292 | setting up a chroot environment or preparing a binary distribution. The |
293 | directory should be specified with an absolute file name. | |
1792d4db | 294 | |
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295 | The GNU C Library includes a daemon called 'nscd', which you may or |
296 | may not want to run. 'nscd' caches name service lookups; it can | |
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297 | dramatically improve performance with NIS+, and may help with DNS as |
298 | well. | |
1792d4db | 299 | |
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300 | One auxiliary program, '/usr/libexec/pt_chown', is installed setuid |
301 | 'root' if the '--enable-pt_chown' configuration option is used. This | |
302 | program is invoked by the 'grantpt' function; it sets the permissions on | |
303 | a pseudoterminal so it can be used by the calling process. If you are | |
304 | using a Linux kernel with the 'devpts' filesystem enabled and mounted at | |
305 | '/dev/pts', you don't need this program. | |
41aa20c2 | 306 | |
bd952512 | 307 | After installation you might want to configure the timezone and |
1f77f049 | 308 | locale installation of your system. The GNU C Library comes with a |
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309 | locale database which gets configured with 'localedef'. For example, to |
310 | set up a German locale with name 'de_DE', simply issue the command | |
311 | 'localedef -i de_DE -f ISO-8859-1 de_DE'. To configure all locales that | |
312 | are supported by the GNU C Library, you can issue from your build | |
313 | directory the command 'make localedata/install-locales'. | |
314 | ||
315 | To configure the locally used timezone, set the 'TZ' environment | |
316 | variable. The script 'tzselect' helps you to select the right value. | |
317 | As an example, for Germany, 'tzselect' would tell you to use | |
318 | 'TZ='Europe/Berlin''. For a system wide installation (the given paths | |
319 | are for an installation with '--prefix=/usr'), link the timezone file | |
320 | which is in '/usr/share/zoneinfo' to the file '/etc/localtime'. For | |
321 | Germany, you might execute 'ln -s /usr/share/zoneinfo/Europe/Berlin | |
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322 | /etc/localtime'. |
323 | ||
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324 | Recommended Tools for Compilation |
325 | ================================= | |
41aa20c2 | 326 | |
80ed68b7 | 327 | We recommend installing the following GNU tools before attempting to |
1f77f049 | 328 | build the GNU C Library: |
41aa20c2 | 329 | |
a8db092e | 330 | * GNU 'make' 3.79 or newer |
41aa20c2 | 331 | |
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332 | You need the latest version of GNU 'make'. Modifying the GNU C |
333 | Library to work with other 'make' programs would be so difficult | |
334 | that we recommend you port GNU 'make' instead. *Really.* We | |
335 | recommend GNU 'make' version 3.79. All earlier versions have | |
6736e93b | 336 | severe bugs or lack features. |
41aa20c2 | 337 | |
4863355a | 338 | * GCC 4.6 or newer |
0e7727f7 | 339 | |
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340 | GCC 4.6 or higher is required. In general it is recommended to use |
341 | the newest version of the compiler that is known to work for | |
342 | building the GNU C Library, as newer compilers usually produce | |
04cb913d | 343 | better code. As of release time, GCC 4.9.2 is the newest compiler |
4863355a | 344 | verified to work to build the GNU C Library. |
91ea72b7 | 345 | |
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346 | You can use whatever compiler you like to compile programs that use |
347 | the GNU C Library. | |
41aa20c2 | 348 | |
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349 | Check the FAQ for any special compiler issues on particular |
350 | platforms. | |
5713a71e | 351 | |
a8db092e | 352 | * GNU 'binutils' 2.22 or later |
41aa20c2 | 353 | |
a8db092e | 354 | You must use GNU 'binutils' (as and ld) to build the GNU C Library. |
7a49a7d5 | 355 | No other assembler or linker has the necessary functionality at the |
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356 | moment. As of release time, GNU 'binutils' 2.25 is the newest |
357 | verified to work to build the GNU C Library. | |
41aa20c2 | 358 | |
a8db092e | 359 | * GNU 'texinfo' 4.7 or later |
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360 | |
361 | To correctly translate and install the Texinfo documentation you | |
a8db092e | 362 | need this version of the 'texinfo' package. Earlier versions do |
41aa20c2 | 363 | not understand all the tags used in the document, and the |
1792d4db | 364 | installation mechanism for the info files is not present or works |
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365 | differently. As of release time, 'texinfo' 5.2 is the newest |
366 | verified to work to build the GNU C Library. | |
41aa20c2 | 367 | |
a8db092e | 368 | * GNU 'awk' 3.1.2, or higher |
00c1176b | 369 | |
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370 | 'awk' is used in several places to generate files. Some 'gawk' |
371 | extensions are used, including the 'asorti' function, which was | |
372 | introduced in version 3.1.2 of 'gawk'. | |
41aa20c2 | 373 | |
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374 | * Perl 5 |
375 | ||
376 | Perl is not required, but it is used if present to test the | |
377 | installation. We may decide to use it elsewhere in the future. | |
41aa20c2 | 378 | |
a8db092e | 379 | * GNU 'sed' 3.02 or newer |
c0389ee4 | 380 | |
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381 | 'Sed' is used in several places to generate files. Most scripts |
382 | work with any version of 'sed'. The known exception is the script | |
383 | 'po2test.sed' in the 'intl' subdirectory which is used to generate | |
384 | 'msgs.h' for the test suite. This script works correctly only with | |
385 | GNU 'sed' 3.02. If you like to run the test suite, you should | |
386 | definitely upgrade 'sed'. | |
c0389ee4 | 387 | |
a8db092e | 388 | If you change any of the 'configure.ac' files you will also need |
0cc70fcf | 389 | |
a8db092e | 390 | * GNU 'autoconf' 2.69 (exactly) |
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391 | |
392 | and if you change any of the message translation files you will need | |
393 | ||
a8db092e | 394 | * GNU 'gettext' 0.10.36 or later |
41aa20c2 | 395 | |
a8db092e | 396 | If you wish to regenerate the 'yacc' parser code in the 'intl' |
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397 | subdirectory you will need |
398 | ||
a8db092e | 399 | * GNU 'bison' 2.7 or later |
cc8623f1 | 400 | |
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401 | You may also need these packages if you upgrade your source tree using |
402 | patches, although we try to avoid this. | |
403 | ||
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404 | Specific advice for GNU/Linux systems |
405 | ===================================== | |
80ed68b7 | 406 | |
a7a93d50 | 407 | If you are installing the GNU C Library on GNU/Linux systems, you need |
d0f5b3f8 | 408 | to have the header files from a 2.6.32 or newer kernel around for |
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409 | reference. These headers must be installed using 'make |
410 | headers_install'; the headers present in the kernel source directory are | |
411 | not suitable for direct use by the GNU C Library. You do not need to | |
412 | use that kernel, just have its headers installed where the GNU C Library | |
413 | can access them, referred to here as INSTALL-DIRECTORY. The easiest way | |
414 | to do this is to unpack it in a directory such as | |
415 | '/usr/src/linux-VERSION'. In that directory, run 'make headers_install | |
1f77f049 | 416 | INSTALL_HDR_PATH=INSTALL-DIRECTORY'. Finally, configure the GNU C |
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417 | Library with the option '--with-headers=INSTALL-DIRECTORY/include'. Use |
418 | the most recent kernel you can get your hands on. (If you are | |
1f77f049 | 419 | cross-compiling the GNU C Library, you need to specify |
a8db092e | 420 | 'ARCH=ARCHITECTURE' in the 'make headers_install' command, where |
1f77f049 | 421 | ARCHITECTURE is the architecture name used by the Linux kernel, such as |
a8db092e | 422 | 'x86' or 'powerpc'.) |
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423 | |
424 | After installing the GNU C Library, you may need to remove or rename | |
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425 | directories such as '/usr/include/linux' and '/usr/include/asm', and |
426 | replace them with copies of directories such as 'linux' and 'asm' from | |
427 | 'INSTALL-DIRECTORY/include'. All directories present in | |
428 | 'INSTALL-DIRECTORY/include' should be copied, except that the GNU C | |
429 | Library provides its own version of '/usr/include/scsi'; the files | |
430 | provided by the kernel should be copied without replacing those provided | |
431 | by the GNU C Library. The 'linux', 'asm' and 'asm-generic' directories | |
432 | are required to compile programs using the GNU C Library; the other | |
433 | directories describe interfaces to the kernel but are not required if | |
434 | not compiling programs using those interfaces. You do not need to copy | |
435 | kernel headers if you did not specify an alternate kernel header source | |
436 | using '--with-headers'. | |
1f77f049 | 437 | |
a7a93d50 | 438 | The Filesystem Hierarchy Standard for GNU/Linux systems expects some |
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439 | components of the GNU C Library installation to be in '/lib' and some in |
440 | '/usr/lib'. This is handled automatically if you configure the GNU C | |
441 | Library with '--prefix=/usr'. If you set some other prefix or allow it | |
442 | to default to '/usr/local', then all the components are installed there. | |
1792d4db | 443 | |
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444 | Reporting Bugs |
445 | ============== | |
41aa20c2 | 446 | |
1f77f049 | 447 | There are probably bugs in the GNU C Library. There are certainly |
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448 | errors and omissions in this manual. If you report them, they will get |
449 | fixed. If you don't, no one will ever know about them and they will | |
450 | remain unfixed for all eternity, if not longer. | |
451 | ||
bd952512 | 452 | It is a good idea to verify that the problem has not already been |
a8db092e | 453 | reported. Bugs are documented in two places: The file 'BUGS' describes |
8b748aed | 454 | a number of well known bugs and the central GNU C Library bug tracking |
a8db092e | 455 | system has a WWW interface at <http://sourceware.org/bugzilla/>. The |
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456 | WWW interface gives you access to open and closed reports. A closed |
457 | report normally includes a patch or a hint on solving the problem. | |
6736e93b | 458 | |
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459 | To report a bug, first you must find it. With any luck, this will be |
460 | the hard part. Once you've found a bug, make sure it's really a bug. A | |
461 | good way to do this is to see if the GNU C Library behaves the same way | |
462 | some other C library does. If so, probably you are wrong and the | |
463 | libraries are right (but not necessarily). If not, one of the libraries | |
464 | is probably wrong. It might not be the GNU C Library. Many historical | |
465 | Unix C libraries permit things that we don't, such as closing a file | |
466 | twice. | |
1792d4db | 467 | |
1f77f049 | 468 | If you think you have found some way in which the GNU C Library does |
1792d4db | 469 | not conform to the ISO and POSIX standards (*note Standards and |
c0389ee4 | 470 | Portability::), that is definitely a bug. Report it! |
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471 | |
472 | Once you're sure you've found a bug, try to narrow it down to the | |
473 | smallest test case that reproduces the problem. In the case of a C | |
474 | library, you really only need to narrow it down to one library function | |
475 | call, if possible. This should not be too difficult. | |
476 | ||
477 | The final step when you have a simple test case is to report the bug. | |
a8db092e | 478 | Do this at <http://www.gnu.org/software/libc/bugs.html>. |
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479 | |
480 | If you are not sure how a function should behave, and this manual | |
481 | doesn't tell you, that's a bug in the manual. Report that too! If the | |
482 | function's behavior disagrees with the manual, then either the library | |
483 | or the manual has a bug, so report the disagreement. If you find any | |
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484 | errors or omissions in this manual, please report them to the bug |
485 | database. If you refer to specific sections of the manual, please | |
486 | include the section names for easier identification. |