lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | @include macros.texi |
| 2 | @include pkgvers.texi |
| 3 | |
| 4 | @ifclear plain |
| 5 | @node Installation, Maintenance, Library Summary, Top |
| 6 | @end ifclear |
| 7 | |
| 8 | @c %MENU% How to install the GNU C Library |
| 9 | @appendix Installing @theglibc{} |
| 10 | |
| 11 | Before you do anything else, you should read the FAQ at |
| 12 | @url{http://sourceware.org/glibc/wiki/FAQ}. It answers common |
| 13 | questions and describes problems you may experience with compilation |
| 14 | and installation. |
| 15 | |
| 16 | Features can be added to @theglibc{} via @dfn{add-on} bundles. These are |
| 17 | separate tar files, which you unpack into the top level of the source |
| 18 | tree. Then you give @code{configure} the @samp{--enable-add-ons} option |
| 19 | to activate them, and they will be compiled into the library. |
| 20 | |
| 21 | You will need recent versions of several GNU tools: definitely GCC and |
| 22 | GNU Make, and possibly others. @xref{Tools for Compilation}, below. |
| 23 | |
| 24 | @ifclear plain |
| 25 | @menu |
| 26 | * Configuring and compiling:: How to compile and test GNU libc. |
| 27 | * Running make install:: How to install it once you've got it |
| 28 | compiled. |
| 29 | * Tools for Compilation:: You'll need these first. |
| 30 | * Linux:: Specific advice for GNU/Linux systems. |
| 31 | * Reporting Bugs:: So they'll get fixed. |
| 32 | @end menu |
| 33 | @end ifclear |
| 34 | |
| 35 | @node Configuring and compiling |
| 36 | @appendixsec Configuring and compiling @theglibc{} |
| 37 | @cindex configuring |
| 38 | @cindex compiling |
| 39 | |
| 40 | @Theglibc{} cannot be compiled in the source directory. You must build |
| 41 | it in a separate build directory. For example, if you have unpacked |
| 42 | the @glibcadj{} sources in @file{/src/gnu/glibc-@var{version}}, |
| 43 | create a directory |
| 44 | @file{/src/gnu/glibc-build} to put the object files in. This allows |
| 45 | removing the whole build directory in case an error occurs, which is |
| 46 | the safest way to get a fresh start and should always be done. |
| 47 | |
| 48 | From your object directory, run the shell script @file{configure} located |
| 49 | at the top level of the source tree. In the scenario above, you'd type |
| 50 | |
| 51 | @smallexample |
| 52 | $ ../glibc-@var{version}/configure @var{args@dots{}} |
| 53 | @end smallexample |
| 54 | |
| 55 | Please note that even though you're building in a separate build |
| 56 | directory, the compilation may need to create or modify files and |
| 57 | directories in the source directory. |
| 58 | |
| 59 | @noindent |
| 60 | @code{configure} takes many options, but the only one that is usually |
| 61 | mandatory is @samp{--prefix}. This option tells @code{configure} |
| 62 | where you want @theglibc{} installed. This defaults to @file{/usr/local}, |
| 63 | but the normal setting to install as the standard system library is |
| 64 | @samp{--prefix=/usr} for @gnulinuxsystems{} and @samp{--prefix=} (an |
| 65 | empty prefix) for @gnuhurdsystems{}. |
| 66 | |
| 67 | It may also be useful to set the @var{CC} and @var{CFLAGS} variables in |
| 68 | the environment when running @code{configure}. @var{CC} selects the C |
| 69 | compiler that will be used, and @var{CFLAGS} sets optimization options |
| 70 | for the compiler. |
| 71 | |
| 72 | The following list describes all of the available options for |
| 73 | @code{configure}: |
| 74 | |
| 75 | @table @samp |
| 76 | @item --prefix=@var{directory} |
| 77 | Install machine-independent data files in subdirectories of |
| 78 | @file{@var{directory}}. The default is to install in @file{/usr/local}. |
| 79 | |
| 80 | @item --exec-prefix=@var{directory} |
| 81 | Install the library and other machine-dependent files in subdirectories |
| 82 | of @file{@var{directory}}. The default is to the @samp{--prefix} |
| 83 | directory if that option is specified, or @file{/usr/local} otherwise. |
| 84 | |
| 85 | @item --with-headers=@var{directory} |
| 86 | Look for kernel header files in @var{directory}, not |
| 87 | @file{/usr/include}. @Theglibc{} needs information from the kernel's header |
| 88 | files describing the interface to the kernel. @Theglibc{} will normally |
| 89 | look in @file{/usr/include} for them, |
| 90 | but if you specify this option, it will look in @var{DIRECTORY} instead. |
| 91 | |
| 92 | This option is primarily of use on a system where the headers in |
| 93 | @file{/usr/include} come from an older version of @theglibc{}. Conflicts can |
| 94 | occasionally happen in this case. You can also use this option if you want to |
| 95 | compile @theglibc{} with a newer set of kernel headers than the ones found in |
| 96 | @file{/usr/include}. |
| 97 | |
| 98 | @item --enable-add-ons[=@var{list}] |
| 99 | Specify add-on packages to include in the build. If this option is |
| 100 | specified with no list, it enables all the add-on packages it finds in |
| 101 | the main source directory; this is the default behavior. You may |
| 102 | specify an explicit list of add-ons to use in @var{list}, separated by |
| 103 | spaces or commas (if you use spaces, remember to quote them from the |
| 104 | shell). Each add-on in @var{list} can be an absolute directory name |
| 105 | or can be a directory name relative to the main source directory, or |
| 106 | relative to the build directory (that is, the current working directory). |
| 107 | For example, @samp{--enable-add-ons=nptl,../glibc-libidn-@var{version}}. |
| 108 | |
| 109 | @item --enable-kernel=@var{version} |
| 110 | This option is currently only useful on @gnulinuxsystems{}. The |
| 111 | @var{version} parameter should have the form X.Y.Z and describes the |
| 112 | smallest version of the Linux kernel the generated library is expected |
| 113 | to support. The higher the @var{version} number is, the less |
| 114 | compatibility code is added, and the faster the code gets. |
| 115 | |
| 116 | @item --with-binutils=@var{directory} |
| 117 | Use the binutils (assembler and linker) in @file{@var{directory}}, not |
| 118 | the ones the C compiler would default to. You can use this option if |
| 119 | the default binutils on your system cannot deal with all the constructs |
| 120 | in @theglibc{}. In that case, @code{configure} will detect the |
| 121 | problem and suppress these constructs, so that the library will still be |
| 122 | usable, but functionality may be lost---for example, you can't build a |
| 123 | shared libc with old binutils. |
| 124 | |
| 125 | @item --without-fp |
| 126 | Use this option if your computer lacks hardware floating-point support |
| 127 | and your operating system does not emulate an FPU. |
| 128 | |
| 129 | @c disable static doesn't work currently |
| 130 | @c @item --disable-static |
| 131 | @c Don't build static libraries. Static libraries aren't that useful these |
| 132 | @c days, but we recommend you build them in case you need them. |
| 133 | |
| 134 | @item --disable-shared |
| 135 | Don't build shared libraries even if it is possible. Not all systems |
| 136 | support shared libraries; you need ELF support and (currently) the GNU |
| 137 | linker. |
| 138 | |
| 139 | @item --disable-profile |
| 140 | Don't build libraries with profiling information. You may want to use |
| 141 | this option if you don't plan to do profiling. |
| 142 | |
| 143 | @item --enable-static-nss |
| 144 | Compile static versions of the NSS (Name Service Switch) libraries. |
| 145 | This is not recommended because it defeats the purpose of NSS; a program |
| 146 | linked statically with the NSS libraries cannot be dynamically |
| 147 | reconfigured to use a different name database. |
| 148 | |
| 149 | @item --without-tls |
| 150 | By default the C library is built with support for thread-local storage |
| 151 | if the used tools support it. By using @samp{--without-tls} this can be |
| 152 | prevented though there generally is no reason since it creates |
| 153 | compatibility problems. |
| 154 | |
| 155 | @item --enable-hardcoded-path-in-tests |
| 156 | By default, dynamic tests are linked to run with the installed C library. |
| 157 | This option hardcodes the newly built C library path in dynamic tests |
| 158 | so that they can be invoked directly. |
| 159 | |
| 160 | @item --enable-lock-elision=yes |
| 161 | Enable lock elision for pthread mutexes by default. |
| 162 | |
| 163 | @pindex pt_chown |
| 164 | @findex grantpt |
| 165 | @item --enable-pt_chown |
| 166 | The file @file{pt_chown} is a helper binary for @code{grantpt} |
| 167 | (@pxref{Allocation, Pseudo-Terminals}) that is installed setuid root to |
| 168 | fix up pseudo-terminal ownership. It is not built by default because |
| 169 | systems using the Linux kernel are commonly built with the @code{devpts} |
| 170 | filesystem enabled and mounted at @file{/dev/pts}, which manages |
| 171 | pseudo-terminal ownership automatically. By using |
| 172 | @samp{--enable-pt_chown}, you may build @file{pt_chown} and install it |
| 173 | setuid and owned by @code{root}. The use of @file{pt_chown} introduces |
| 174 | additional security risks to the system and you should enable it only if |
| 175 | you understand and accept those risks. |
| 176 | |
| 177 | @item --disable-werror |
| 178 | By default, @theglibc{} is built with @option{-Werror}. If you wish |
| 179 | to build without this option (for example, if building with a newer |
| 180 | version of GCC than this version of @theglibc{} was tested with, so |
| 181 | new warnings cause the build with @option{-Werror} to fail), you can |
| 182 | configure with @option{--disable-werror}. |
| 183 | |
| 184 | @item --disable-mathvec |
| 185 | By default for x86_64, @theglibc{} is built with vector math library. |
| 186 | Use this option to disable vector math library. |
| 187 | |
| 188 | @item --build=@var{build-system} |
| 189 | @itemx --host=@var{host-system} |
| 190 | These options are for cross-compiling. If you specify both options and |
| 191 | @var{build-system} is different from @var{host-system}, @code{configure} |
| 192 | will prepare to cross-compile @theglibc{} from @var{build-system} to be used |
| 193 | on @var{host-system}. You'll probably need the @samp{--with-headers} |
| 194 | option too, and you may have to override @var{configure}'s selection of |
| 195 | the compiler and/or binutils. |
| 196 | |
| 197 | If you only specify @samp{--host}, @code{configure} will prepare for a |
| 198 | native compile but use what you specify instead of guessing what your |
| 199 | system is. This is most useful to change the CPU submodel. For example, |
| 200 | if @code{configure} guesses your machine as @code{i686-pc-linux-gnu} but |
| 201 | you want to compile a library for 586es, give |
| 202 | @samp{--host=i586-pc-linux-gnu} or just @samp{--host=i586-linux} and add |
| 203 | the appropriate compiler flags (@samp{-mcpu=i586} will do the trick) to |
| 204 | @var{CFLAGS}. |
| 205 | |
| 206 | If you specify just @samp{--build}, @code{configure} will get confused. |
| 207 | |
| 208 | @item --with-pkgversion=@var{version} |
| 209 | Specify a description, possibly including a build number or build |
| 210 | date, of the binaries being built, to be included in |
| 211 | @option{--version} output from programs installed with @theglibc{}. |
| 212 | For example, @option{--with-pkgversion='FooBar GNU/Linux glibc build |
| 213 | 123'}. The default value is @samp{GNU libc}. |
| 214 | |
| 215 | @item --with-bugurl=@var{url} |
| 216 | Specify the URL that users should visit if they wish to report a bug, |
| 217 | to be included in @option{--help} output from programs installed with |
| 218 | @theglibc{}. The default value refers to the main bug-reporting |
| 219 | information for @theglibc{}. |
| 220 | @end table |
| 221 | |
| 222 | To build the library and related programs, type @code{make}. This will |
| 223 | produce a lot of output, some of which may look like errors from |
| 224 | @code{make} but isn't. Look for error messages from @code{make} |
| 225 | containing @samp{***}. Those indicate that something is seriously wrong. |
| 226 | |
| 227 | The compilation process can take a long time, depending on the |
| 228 | configuration and the speed of your machine. Some complex modules may |
| 229 | take a very long time to compile, as much as several minutes on slower |
| 230 | machines. Do not panic if the compiler appears to hang. |
| 231 | |
| 232 | If you want to run a parallel make, simply pass the @samp{-j} option |
| 233 | with an appropriate numeric parameter to @code{make}. You need a recent |
| 234 | GNU @code{make} version, though. |
| 235 | |
| 236 | To build and run test programs which exercise some of the library |
| 237 | facilities, type @code{make check}. If it does not complete |
| 238 | successfully, do not use the built library, and report a bug after |
| 239 | verifying that the problem is not already known. @xref{Reporting Bugs}, |
| 240 | for instructions on reporting bugs. Note that some of the tests assume |
| 241 | they are not being run by @code{root}. We recommend you compile and |
| 242 | test @theglibc{} as an unprivileged user. |
| 243 | |
| 244 | Before reporting bugs make sure there is no problem with your system. |
| 245 | The tests (and later installation) use some pre-existing files of the |
| 246 | system such as @file{/etc/passwd}, @file{/etc/nsswitch.conf} and others. |
| 247 | These files must all contain correct and sensible content. |
| 248 | |
| 249 | Normally, @code{make check} will run all the tests before reporting |
| 250 | all problems found and exiting with error status if any problems |
| 251 | occurred. You can specify @samp{stop-on-test-failure=y} when running |
| 252 | @code{make check} to make the test run stop and exit with an error |
| 253 | status immediately when a failure occurs. |
| 254 | |
| 255 | To format the @cite{GNU C Library Reference Manual} for printing, type |
| 256 | @w{@code{make dvi}}. You need a working @TeX{} installation to do |
| 257 | this. The distribution builds the on-line formatted version of the |
| 258 | manual, as Info files, as part of the build process. You can build |
| 259 | them manually with @w{@code{make info}}. |
| 260 | |
| 261 | The library has a number of special-purpose configuration parameters |
| 262 | which you can find in @file{Makeconfig}. These can be overwritten with |
| 263 | the file @file{configparms}. To change them, create a |
| 264 | @file{configparms} in your build directory and add values as appropriate |
| 265 | for your system. The file is included and parsed by @code{make} and has |
| 266 | to follow the conventions for makefiles. |
| 267 | |
| 268 | It is easy to configure @theglibc{} for cross-compilation by |
| 269 | setting a few variables in @file{configparms}. Set @code{CC} to the |
| 270 | cross-compiler for the target you configured the library for; it is |
| 271 | important to use this same @code{CC} value when running |
| 272 | @code{configure}, like this: @samp{CC=@var{target}-gcc configure |
| 273 | @var{target}}. Set @code{BUILD_CC} to the compiler to use for programs |
| 274 | run on the build system as part of compiling the library. You may need to |
| 275 | set @code{AR} to cross-compiling versions of @code{ar} |
| 276 | if the native tools are not configured to work with |
| 277 | object files for the target you configured for. When cross-compiling |
| 278 | @theglibc{}, it may be tested using @samp{make check |
| 279 | test-wrapper="@var{srcdir}/scripts/cross-test-ssh.sh @var{hostname}"}, |
| 280 | where @var{srcdir} is the absolute directory name for the main source |
| 281 | directory and @var{hostname} is the host name of a system that can run |
| 282 | the newly built binaries of @theglibc{}. The source and build |
| 283 | directories must be visible at the same locations on both the build |
| 284 | system and @var{hostname}. |
| 285 | |
| 286 | In general, when testing @theglibc{}, @samp{test-wrapper} may be set |
| 287 | to the name and arguments of any program to run newly built binaries. |
| 288 | This program must preserve the arguments to the binary being run, its |
| 289 | working directory and the standard input, output and error file |
| 290 | descriptors. If @samp{@var{test-wrapper} env} will not work to run a |
| 291 | program with environment variables set, then @samp{test-wrapper-env} |
| 292 | must be set to a program that runs a newly built program with |
| 293 | environment variable assignments in effect, those assignments being |
| 294 | specified as @samp{@var{var}=@var{value}} before the name of the |
| 295 | program to be run. If multiple assignments to the same variable are |
| 296 | specified, the last assignment specified must take precedence. |
| 297 | Similarly, if @samp{@var{test-wrapper} env -i} will not work to run a |
| 298 | program with an environment completely empty of variables except those |
| 299 | directly assigned, then @samp{test-wrapper-env-only} must be set; its |
| 300 | use has the same syntax as @samp{test-wrapper-env}, the only |
| 301 | difference in its semantics being starting with an empty set of |
| 302 | environment variables rather than the ambient set. |
| 303 | |
| 304 | |
| 305 | @node Running make install |
| 306 | @appendixsec Installing the C Library |
| 307 | @cindex installing |
| 308 | |
| 309 | To install the library and its header files, and the Info files of the |
| 310 | manual, type @code{make install}. This will |
| 311 | build things, if necessary, before installing them; however, you should |
| 312 | still compile everything first. If you are installing @theglibc{} as your |
| 313 | primary C library, we recommend that you shut the system down to |
| 314 | single-user mode first, and reboot afterward. This minimizes the risk |
| 315 | of breaking things when the library changes out from underneath. |
| 316 | |
| 317 | @samp{make install} will do the entire job of upgrading from a |
| 318 | previous installation of @theglibc{} version 2.x. There may sometimes |
| 319 | be headers |
| 320 | left behind from the previous installation, but those are generally |
| 321 | harmless. If you want to avoid leaving headers behind you can do |
| 322 | things in the following order. |
| 323 | |
| 324 | You must first build the library (@samp{make}), optionally check it |
| 325 | (@samp{make check}), switch the include directories and then install |
| 326 | (@samp{make install}). The steps must be done in this order. Not moving |
| 327 | the directory before install will result in an unusable mixture of header |
| 328 | files from both libraries, but configuring, building, and checking the |
| 329 | library requires the ability to compile and run programs against the old |
| 330 | library. The new @file{/usr/include}, after switching the include |
| 331 | directories and before installing the library should contain the Linux |
| 332 | headers, but nothing else. If you do this, you will need to restore |
| 333 | any headers from libraries other than @theglibc{} yourself after installing the |
| 334 | library. |
| 335 | |
| 336 | You can install @theglibc{} somewhere other than where you configured |
| 337 | it to go by setting the @code{DESTDIR} GNU standard make variable on |
| 338 | the command line for @samp{make install}. The value of this variable |
| 339 | is prepended to all the paths for installation. This is useful when |
| 340 | setting up a chroot environment or preparing a binary distribution. |
| 341 | The directory should be specified with an absolute file name. Installing |
| 342 | with the @code{prefix} and @code{exec_prefix} GNU standard make variables |
| 343 | set is not supported. |
| 344 | |
| 345 | @Theglibc{} includes a daemon called @code{nscd}, which you |
| 346 | may or may not want to run. @code{nscd} caches name service lookups; it |
| 347 | can dramatically improve performance with NIS+, and may help with DNS as |
| 348 | well. |
| 349 | |
| 350 | One auxiliary program, @file{/usr/libexec/pt_chown}, is installed setuid |
| 351 | @code{root} if the @samp{--enable-pt_chown} configuration option is used. |
| 352 | This program is invoked by the @code{grantpt} function; it sets the |
| 353 | permissions on a pseudoterminal so it can be used by the calling process. |
| 354 | If you are using a Linux kernel with the @code{devpts} filesystem enabled |
| 355 | and mounted at @file{/dev/pts}, you don't need this program. |
| 356 | |
| 357 | After installation you might want to configure the timezone and locale |
| 358 | installation of your system. @Theglibc{} comes with a locale |
| 359 | database which gets configured with @code{localedef}. For example, to |
| 360 | set up a German locale with name @code{de_DE}, simply issue the command |
| 361 | @samp{localedef -i de_DE -f ISO-8859-1 de_DE}. To configure all locales |
| 362 | that are supported by @theglibc{}, you can issue from your build directory the |
| 363 | command @samp{make localedata/install-locales}. |
| 364 | |
| 365 | To configure the locally used timezone, set the @code{TZ} environment |
| 366 | variable. The script @code{tzselect} helps you to select the right value. |
| 367 | As an example, for Germany, @code{tzselect} would tell you to use |
| 368 | @samp{TZ='Europe/Berlin'}. For a system wide installation (the given |
| 369 | paths are for an installation with @samp{--prefix=/usr}), link the |
| 370 | timezone file which is in @file{/usr/share/zoneinfo} to the file |
| 371 | @file{/etc/localtime}. For Germany, you might execute @samp{ln -s |
| 372 | /usr/share/zoneinfo/Europe/Berlin /etc/localtime}. |
| 373 | |
| 374 | @node Tools for Compilation |
| 375 | @appendixsec Recommended Tools for Compilation |
| 376 | @cindex installation tools |
| 377 | @cindex tools, for installing library |
| 378 | |
| 379 | We recommend installing the following GNU tools before attempting to |
| 380 | build @theglibc{}: |
| 381 | |
| 382 | @itemize @bullet |
| 383 | @item |
| 384 | GNU @code{make} 3.79 or newer |
| 385 | |
| 386 | You need the latest version of GNU @code{make}. Modifying @theglibc{} |
| 387 | to work with other @code{make} programs would be so difficult that |
| 388 | we recommend you port GNU @code{make} instead. @strong{Really.} We |
| 389 | recommend GNU @code{make} version 3.79. All earlier versions have severe |
| 390 | bugs or lack features. |
| 391 | |
| 392 | @item |
| 393 | GCC 4.6 or newer |
| 394 | |
| 395 | GCC 4.6 or higher is required. In general it is recommended to use |
| 396 | the newest version of the compiler that is known to work for building |
| 397 | @theglibc{}, as newer compilers usually produce better code. As of |
| 398 | release time, GCC 4.9.2 is the newest compiler verified to work to build |
| 399 | @theglibc{}. |
| 400 | |
| 401 | You can use whatever compiler you like to compile programs that use |
| 402 | @theglibc{}. |
| 403 | |
| 404 | Check the FAQ for any special compiler issues on particular platforms. |
| 405 | |
| 406 | @item |
| 407 | GNU @code{binutils} 2.22 or later |
| 408 | |
| 409 | You must use GNU @code{binutils} (as and ld) to build @theglibc{}. |
| 410 | No other assembler or linker has the necessary functionality at the |
| 411 | moment. As of release time, GNU @code{binutils} 2.25 is the newest |
| 412 | verified to work to build @theglibc{}. |
| 413 | |
| 414 | @item |
| 415 | GNU @code{texinfo} 4.7 or later |
| 416 | |
| 417 | To correctly translate and install the Texinfo documentation you need |
| 418 | this version of the @code{texinfo} package. Earlier versions do not |
| 419 | understand all the tags used in the document, and the installation |
| 420 | mechanism for the info files is not present or works differently. |
| 421 | As of release time, @code{texinfo} 5.2 is the newest verified to work |
| 422 | to build @theglibc{}. |
| 423 | |
| 424 | @item |
| 425 | GNU @code{awk} 3.1.2, or higher |
| 426 | |
| 427 | @code{awk} is used in several places to generate files. |
| 428 | Some @code{gawk} extensions are used, including the @code{asorti} |
| 429 | function, which was introduced in version 3.1.2 of @code{gawk}. |
| 430 | |
| 431 | @item |
| 432 | Perl 5 |
| 433 | |
| 434 | Perl is not required, but it is used if present to test the |
| 435 | installation. We may decide to use it elsewhere in the future. |
| 436 | |
| 437 | @item |
| 438 | GNU @code{sed} 3.02 or newer |
| 439 | |
| 440 | @code{Sed} is used in several places to generate files. Most scripts work |
| 441 | with any version of @code{sed}. The known exception is the script |
| 442 | @code{po2test.sed} in the @code{intl} subdirectory which is used to |
| 443 | generate @code{msgs.h} for the test suite. This script works correctly |
| 444 | only with GNU @code{sed} 3.02. If you like to run the test suite, you |
| 445 | should definitely upgrade @code{sed}. |
| 446 | |
| 447 | @end itemize |
| 448 | |
| 449 | @noindent |
| 450 | If you change any of the @file{configure.ac} files you will also need |
| 451 | |
| 452 | @itemize @bullet |
| 453 | @item |
| 454 | GNU @code{autoconf} 2.69 (exactly) |
| 455 | @end itemize |
| 456 | |
| 457 | @noindent |
| 458 | and if you change any of the message translation files you will need |
| 459 | |
| 460 | @itemize @bullet |
| 461 | @item |
| 462 | GNU @code{gettext} 0.10.36 or later |
| 463 | @end itemize |
| 464 | |
| 465 | @noindent |
| 466 | If you wish to regenerate the @code{yacc} parser code in the @file{intl} |
| 467 | subdirectory you will need |
| 468 | |
| 469 | @itemize @bullet |
| 470 | @item |
| 471 | GNU @code{bison} 2.7 or later |
| 472 | @end itemize |
| 473 | |
| 474 | @noindent |
| 475 | You may also need these packages if you upgrade your source tree using |
| 476 | patches, although we try to avoid this. |
| 477 | |
| 478 | @node Linux |
| 479 | @appendixsec Specific advice for @gnulinuxsystems{} |
| 480 | @cindex kernel header files |
| 481 | |
| 482 | If you are installing @theglibc{} on @gnulinuxsystems{}, you need to have |
| 483 | the header files from a 2.6.32 or newer kernel around for reference. |
| 484 | These headers must be installed using @samp{make headers_install}; the |
| 485 | headers present in the kernel source directory are not suitable for |
| 486 | direct use by @theglibc{}. You do not need to use that kernel, just have |
| 487 | its headers installed where @theglibc{} can access them, referred to here as |
| 488 | @var{install-directory}. The easiest way to do this is to unpack it |
| 489 | in a directory such as @file{/usr/src/linux-@var{version}}. In that |
| 490 | directory, run @samp{make headers_install |
| 491 | INSTALL_HDR_PATH=@var{install-directory}}. Finally, configure @theglibc{} |
| 492 | with the option @samp{--with-headers=@var{install-directory}/include}. |
| 493 | Use the most recent kernel you can get your hands on. (If you are |
| 494 | cross-compiling @theglibc{}, you need to specify |
| 495 | @samp{ARCH=@var{architecture}} in the @samp{make headers_install} |
| 496 | command, where @var{architecture} is the architecture name used by the |
| 497 | Linux kernel, such as @samp{x86} or @samp{powerpc}.) |
| 498 | |
| 499 | After installing @theglibc{}, you may need to remove or rename |
| 500 | directories such as @file{/usr/include/linux} and |
| 501 | @file{/usr/include/asm}, and replace them with copies of directories |
| 502 | such as @file{linux} and @file{asm} from |
| 503 | @file{@var{install-directory}/include}. All directories present in |
| 504 | @file{@var{install-directory}/include} should be copied, except that |
| 505 | @theglibc{} provides its own version of @file{/usr/include/scsi}; the |
| 506 | files provided by the kernel should be copied without replacing those |
| 507 | provided by @theglibc{}. The @file{linux}, @file{asm} and |
| 508 | @file{asm-generic} directories are required to compile programs using |
| 509 | @theglibc{}; the other directories describe interfaces to the kernel but |
| 510 | are not required if not compiling programs using those interfaces. |
| 511 | You do not need to copy kernel headers if you did not specify an |
| 512 | alternate kernel header source using @samp{--with-headers}. |
| 513 | |
| 514 | The Filesystem Hierarchy Standard for @gnulinuxsystems{} expects some |
| 515 | components of the @glibcadj{} installation to be in |
| 516 | @file{/lib} and some in @file{/usr/lib}. This is handled automatically |
| 517 | if you configure @theglibc{} with @samp{--prefix=/usr}. If you set some other |
| 518 | prefix or allow it to default to @file{/usr/local}, then all the |
| 519 | components are installed there. |
| 520 | |
| 521 | @node Reporting Bugs |
| 522 | @appendixsec Reporting Bugs |
| 523 | @cindex reporting bugs |
| 524 | @cindex bugs, reporting |
| 525 | |
| 526 | There are probably bugs in @theglibc{}. There are certainly |
| 527 | errors and omissions in this manual. If you report them, they will get |
| 528 | fixed. If you don't, no one will ever know about them and they will |
| 529 | remain unfixed for all eternity, if not longer. |
| 530 | |
| 531 | It is a good idea to verify that the problem has not already been |
| 532 | reported. Bugs are documented in two places: The file @file{BUGS} |
| 533 | describes a number of well known bugs and the central @glibcadj{} |
| 534 | bug tracking system has a |
| 535 | WWW interface at |
| 536 | @url{http://sourceware.org/bugzilla/}. The WWW |
| 537 | interface gives you access to open and closed reports. A closed report |
| 538 | normally includes a patch or a hint on solving the problem. |
| 539 | |
| 540 | To report a bug, first you must find it. With any luck, this will be the |
| 541 | hard part. Once you've found a bug, make sure it's really a bug. A |
| 542 | good way to do this is to see if @theglibc{} behaves the same way |
| 543 | some other C library does. If so, probably you are wrong and the |
| 544 | libraries are right (but not necessarily). If not, one of the libraries |
| 545 | is probably wrong. It might not be @theglibc{}. Many historical |
| 546 | Unix C libraries permit things that we don't, such as closing a file |
| 547 | twice. |
| 548 | |
| 549 | If you think you have found some way in which @theglibc{} does not |
| 550 | conform to the ISO and POSIX standards (@pxref{Standards and |
| 551 | Portability}), that is definitely a bug. Report it! |
| 552 | |
| 553 | Once you're sure you've found a bug, try to narrow it down to the |
| 554 | smallest test case that reproduces the problem. In the case of a C |
| 555 | library, you really only need to narrow it down to one library |
| 556 | function call, if possible. This should not be too difficult. |
| 557 | |
| 558 | The final step when you have a simple test case is to report the bug. |
| 559 | Do this at @value{REPORT_BUGS_TO}. |
| 560 | |
| 561 | If you are not sure how a function should behave, and this manual |
| 562 | doesn't tell you, that's a bug in the manual. Report that too! If the |
| 563 | function's behavior disagrees with the manual, then either the library |
| 564 | or the manual has a bug, so report the disagreement. If you find any |
| 565 | errors or omissions in this manual, please report them to the |
| 566 | bug database. If you refer to specific |
| 567 | sections of the manual, please include the section names for easier |
| 568 | identification. |