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Diffstat (limited to 'INSTALL')
| -rw-r--r-- | INSTALL | 175 |
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@@ -0,0 +1,175 @@ +Build Instructions +------------------ + +* Requirements + ------------ + + - A POSIX-compliant C development environment + - GNU make version 3.81 or later + - skalibs version 2.6.1.0 or later: http://skarnet.org/software/skalibs/ + + This software will run on any operating system that implements +POSIX.1-2008, available at: + http://pubs.opengroup.org/onlinepubs/9699919799/ + + +* Standard usage + -------------- + + ./configure && make && sudo make install + + will work for most users. + It will install the binaries in /bin and the static libraries in +/usr/lib/utmps. + + Please note that static libraries in /usr/lib/utmps *will not* +be found by a default linker invocation: you need -L/usr/lib/utmps. +Other skarnet.org software automatically handles that case if the +default configuration is used, but if you change the configuration, +remember to use the appropriate --with-lib configure option. + + You can strip the binaries and libraries of their extra symbols via +"make strip" before the "make install" phase. It will shave a few bytes +off them. + + +* Customization + ------------- + + You can customize paths via flags given to configure. + See ./configure --help for a list of all available configure options. + + +* Environment variables + --------------------- + + Controlling a build process via environment variables is a big and +dangerous hammer. You should try and pass flags to configure instead; +nevertheless, a few standard environment variables are recognized. + + If the CC environment variable is set, its value will override compiler +detection by configure. The --host=HOST option will still add a HOST- +prefix to the value of CC. + + The values of CFLAGS, CPPFLAGS and LDFLAGS will be appended to flags +auto-detected by configure. To entirely override the flags set by +configure instead, use make variables. + + +* Make variables + -------------- + + You can invoke make with a few variables for more configuration. + + CC, CFLAGS, CPPFLAGS, LDFLAGS, LDLIBS, AR, RANLIB, STRIP, INSTALL and +CROSS_COMPILE can all be overridden on the make command line. This is +an even bigger hammer than running ./configure with environment +variables, so it is advised to only do this when it is the only way of +obtaining the behaviour you want. + + DESTDIR can be given on the "make install" command line in order to +install to a staging directory. + + +* Shared libraries + ---------------- + + Software from skarnet.org is small enough that shared libraries are +generally not worth using. Static linking is simpler and incurs less +runtime overhead and less points of failure: so by default, shared +libraries are not built and binaries are linked against the static +versions of the skarnet.org libraries. Nevertheless, you can: + * build shared libraries: --enable-shared + * link binaries against shared libraries: --disable-allstatic + + +* Static binaries + --------------- + + By default, binaries are linked against static versions of all the +libraries they depend on, except for the libc. You can enforce +linking against the static libc with --enable-static-libc. + + (If you are using a GNU/Linux system, be aware that the GNU libc +behaves badly with static linking and produces huge executables, +which is why it is not the default. Other libcs are better suited +to static linking, for instance musl: http://musl-libc.org/. If +you're using utmps, chances are you're running musl, or a similar +libc, anyway.) + + +* Cross-compilation + ----------------- + + skarnet.org packages centralize all the difficulty of +cross-compilation in one place: skalibs. Once you have +cross-compiled skalibs, the rest is easy. + + * Use the --host=HOST option to configure, HOST being the triplet +for your target. + * Make sure your cross-toolchain binaries (i.e. prefixed with HOST-) +are accessible via your PATH environment variable. + * Make sure to use the correct version of skalibs for your target, +and the correct sysdeps directory, making use of the +--with-include, --with-lib, --with-dynlib and --with-sysdeps +options as necessary. + + +* The slashpackage convention + --------------------------- + + The slashpackage convention (http://cr.yp.to/slashpackage.html) +is a package installation scheme that provides a few guarantees +over other conventions such as the FHS, for instance fixed +absolute pathnames. skarnet.org packages support it: use the +--enable-slashpackage option to configure, or +--enable-slashpackage=DIR for a prefixed DIR/package tree. +This option will activate slashpackage support during the build +and set slashpackage-compatible installation directories. +If $package_home is the home of the package, defined as +DIR/package/$category/$package-$version with the variables +read from the package/info file, then: + + --dynlibdir is set to $package_home/library.so + --bindir is set to $package_home/command + --sbindir is also set to $package_home/command (slashpackage +differentiates root-only binaries by their Unix rights, not their +location in the filesystem) + --libexecdir is also set to $package_home/command (slashpackage +does not need a specific directory for internal binaries) + --libdir is set to $package_home/library + --includedir is set to $package_home/include + + --prefix is pretty much ignored when you use --enable-slashpackage. +You should probably not use both --enable-slashpackage and --prefix. + + When using slashpackage, two additional Makefile targets are +available after "make install": + - "make update" changes the default version of the software to the +freshly installed one. (This is useful when you have several installed +versions of the same software, which slashpackage supports.) + - "make -L global-links" adds links from /command and /library.so to the +default version of the binaries and shared libraries. The "-L" option to +make is necessary because targets are symbolic links, and the default make +behaviour is to check the pointed file's timestamp and not the symlink's +timestamp. + + +* Absolute pathnames + ------------------ + + You may want to use fixed absolute pathnames even if you're not +following the slashpackage convention: for instance, the Nix packaging +system prefers calling binaries with immutable paths rather than rely on +PATH resolution. If you are in that case, use the --enable-absolute-paths +option to configure. This will ensure that programs calling binaries from +this package will call them with their full installation path (in bindir) +without relying on a PATH search. + + +* Out-of-tree builds + ------------------ + + skarnet.org packages do not support out-of-tree builds. They +are small, so it does not cost much to duplicate the entire +source tree if parallel builds are needed. |