# Installing GCC

# Old installation documentation

Note most of this information is out of date and superseded by the previous chapters of this manual. It is provided for historical reference only, because of a lack of volunteers to merge it into the main manual.

Here is the procedure for installing GCC on a GNU or Unix system.

1. If you have chosen a configuration for GCC which requires other GNU tools (such as GAS or the GNU linker) instead of the standard system tools, install the required tools in the build directory under the names `as`, `ld` or whatever is appropriate.

   Alternatively, you can do subsequent compilation using a value of the `PATH` environment variable such that the necessary GNU tools come before the standard system tools.

2. Specify the host, build and target machine configurations. You do this when you run the `configure` script.

   The build machine is the system which you are using, the host machine is the system where you want to run the resulting compiler (normally the build machine), and the target machine is the system for which you want the compiler to generate code.

   If you are building a compiler to produce code for the machine it runs on (a native compiler), you normally do not need to specify any operands to `configure`; it will try to guess the type of machine you are on and use that as the build, host and target machines. So you don’t need to specify a configuration when building a native compiler unless `configure` cannot figure out what your configuration is or guesses wrong.

   In those cases, specify the build machine’s configuration name with the `--host` option; the host and target will default to be the same as the host machine.

   Here is an example:

       ./configure --host=sparc-sun-sunos4.1

   A configuration name may be canonical or it may be more or less abbreviated.

   A canonical configuration name has three parts, separated by dashes. It looks like this: ‘`cpu-company-system`’. (The three parts may themselves contain dashes; `configure` can figure out which dashes serve which purpose.) For example, ‘`m68k-sun-sunos4.1`’ specifies a Sun 3.

   You can also replace parts of the configuration by nicknames or aliases. For example, ‘`sun3`’ stands for ‘`m68k-sun`’, so ‘`sun3-sunos4.1`’ is another way to specify a Sun 3.

   You can specify a version number after any of the system types, and some of the CPU types. In most cases, the version is irrelevant, and will be ignored. So you might as well specify the version if you know it.

   See Configurations, for a list of supported configuration names and notes on many of the configurations. You should check the notes in that section before proceeding any further with the installation of GCC.

## Configurations Supported by GCC

Here are the possible CPU types:

> 1750a, a29k, alpha, arm, avr, cn, clipper, dsp16xx, elxsi, fr30, h8300, hppa1.0, hppa1.1, i370, i386, i486, i586, i686, i786, i860, i960, ip2k, m32r, m68000, m68k, m88k, mcore, mips, mipsel, mips64, mips64el, mn10200, mn10300, ns32k, pdp11, powerpc, powerpcle, romp, rs6000, sh, sparc, sparclite, sparc64, v850, vax, we32k.

Here are the recognized company names. As you can see, customary abbreviations are used rather than the longer official names.

> acorn, alliant, altos, apollo, apple, att, bull, cbm, convergent, convex, crds, dec, dg, dolphin, elxsi, encore, harris, hitachi, hp, ibm, intergraph, isi, mips, motorola, ncr, next, ns, omron, plexus, sequent, sgi, sony, sun, tti, unicom, wrs.

The company name is meaningful only to disambiguate when the rest of the information supplied is insufficient. You can omit it, writing just ‘`cpu-system`’, if it is not needed. For example, ‘`vax-ultrix4.2`’ is equivalent to ‘`vax-dec-ultrix4.2`’.

Here is a list of system types:

> 386bsd, aix, acis, amigaos, aos, aout, aux, bosx, bsd, clix, coff, ctix, cxux, dgux, dynix, ebmon, ecoff, elf, esix, freebsd, hms, genix, gnu, linux, linux-gnu, hiux, hpux, iris, irix, isc, luna, lynxos, mach, minix, msdos, mvs, netbsd, newsos, nindy, ns, osf, osfrose, ptx, riscix, riscos, rtu, sco, sim, solaris, sunos, sym, sysv, udi, ultrix, unicos, uniplus, unos, vms, vsta, vxworks, winnt, xenix.

You can omit the system type; then `configure` guesses the operating system from the CPU and company.

You can add a version number to the system type; this may or may not make a difference. For example, you can write ‘`bsd4.3`’ or ‘`bsd4.4`’ to distinguish versions of BSD. In practice, the version number is most needed for ‘`sysv3`’ and ‘`sysv4`’, which are often treated differently.

‘`linux-gnu`’ is the canonical name for the GNU/Linux target; however GCC will also accept ‘`linux`’. The version of the kernel in use is not relevant on these systems. A suffix such as ‘`libc1`’ or ‘`aout`’ distinguishes major versions of the C library; all of the suffixed versions are obsolete.

If you specify an impossible combination such as ‘`i860-dg-vms`’, then you may get an error message from `configure`, or it may ignore part of the information and do the best it can with the rest. `configure` always prints the canonical name for the alternative that it used. GCC does not support all possible alternatives.

Often a particular model of machine has a name. Many machine names are recognized as aliases for CPU/company combinations. Thus, the machine name ‘`sun3`’, mentioned above, is an alias for ‘`m68k-sun`’. Sometimes we accept a company name as a machine name, when the name is popularly used for a particular machine. Here is a table of the known machine names:

> 3300, 3b1, 3bn, 7300, altos3068, altos, apollo68, att-7300, balance, convex-cn, crds, decstation-3100, decstation, delta, encore, fx2800, gmicro, hp7nn, hp8nn, hp9k2nn, hp9k3nn, hp9k7nn, hp9k8nn, iris4d, iris, isi68, m3230, magnum, merlin, miniframe, mmax, news-3600, news800, news, next, pbd, pc532, pmax, powerpc, powerpcle, ps2, risc-news, rtpc, sun2, sun386i, sun386, sun3, sun4, symmetry, tower-32, tower.

Remember that a machine name specifies both the cpu type and the company name.

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