Installing GNU CC
*****************

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

 1. If you have built GNU CC previously in the same directory for a different target machine, do make distclean to delete all files that might be invalid.  One of the files this deletes is Makefile; if make distclean complains that Makefile does not exist, it probably means that the directory is already suitably clean.

 2. On a System V release 4 system, make sure /usr/bin precedes /usr/ucb in PATH.  The cc command in /usr/ucb uses libraries which have bugs.

 3. Specify the host and target machine configurations.  You do this by running the file configure with appropriate arguments.

     If you are building a compiler to produce code for the machine it runs on, specify just one machine type.  Use the --target option; the host type will default to be the same as the target.  (For information on building a cross-compiler, see Cross-Compiler.)  The command looks like this:

          configure --target=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 also use simply sun3-sunos, since the version of SunOS is assumed by default to be version 4.  sun3-bsd also works, since configure knows that the only BSD variant on a Sun 3 is SunOS.

     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.

     Here are the possible CPU types:

          a29k, alpha, arm, cN, elxsi, hppa1.0, hppa1.1, i386, i860, i960, m68000, m68k, m88k, mips, ns32k, pyramid, romp, rs6000, sparc, vax, we32k.

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

          alliant, altos, apollo, att, cbm, convergent, convex, crds, dec, dg, encore, harris, hp, ibm, mips, motorola, ncr, next, ns, omron, sequent, sgi, sony, sun, tti, unicom.

     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:

          aix, aos, bsd, ctix, dgux, dynix, genix, hpux, isc, linux, luna, mach, minix, newsos, osf, osfrose, riscos, sco, sunos, sysv, ultrix, unos, vms.

     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.

     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.

     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, 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.

     There are four additional options you can specify independently to describe variant hardware and software configurations.  These are --with-gnu-as, --with-gnu-ld, --with-stabs and --nfp.

     --with-gnu-as
          On certain systems, you must specify whether you want GNU CC to work with the usual compilation tools or with the GNU compilation tools (including GAS).  Use the --with-gnu-as argument when you run configure, if you want to use the GNU tools.  (Specify --with-gnu-ld as well, since on these systems GAS works only with the GNU linker.)  The systems where this makes a difference are i386-ANYTHING-sysv, i860-ANYTHING-bsd, m68k-hp-hpux, m68k-sony-bsd, m68k-altos-sysv, m68000-hp-hpux, and m68000-att-sysv.  On any other system, --with-gnu-as has no effect.

     --with-gnu-ld
          Specify the option --with-gnu-ld if you plan to use the GNU linker.  This inhibits the installation of collect2, a program which otherwise serves as a front-end for the system's linker on most configurations.

     --with-stabs
          On MIPS based systems, you must specify whether you want GNU CC to create the normal ECOFF debugging format, or to use BSD-style stabs passed through the ECOFF symbol table.  The normal ECOFF debug format cannot fully handle languages other than C.  BSD stabs format can handle other languages, but it only works with the GNU debugger GDB.

          Normally, GNU CC uses the ECOFF debugging format by default; if you prefer BSD stabs, specify --with-stabs when you configure GNU CC.

          No matter which default you choose when you configure GNU CC, the user can use the -gcoff and -gstabs+ options to specify explicitly the debug format for a particular compilation.

     --nfp
          On certain systems, you must specify whether the machine has a floating point unit.  These systems are m68k-sun-sunosN and m68k-isi-bsd.  On any other system, --nfp currently has no effect, though perhaps there are other systems where it could usefully make a difference.

     If you want to install your own homemade configuration files, you can use local as the company name to access them.  If you use configuration CPU-local, the entire configuration name is used to form the configuration file names.

     Thus, if you specify m68k-local, then the files used are m68k-local.md, m68k-local.h, m68k-local.c, xm-m68k-local.h, t-m68k-local, and x-m68k-local.

     Here is a list of configurations that have special treatment or special things you must know:

     alpha-*-osf1
          Systems using processors that implement the DEC Alpha architecture and are running the OSF/1 operating system. (VMS on the Alpha is not currently supported by GNU CC.)  As of this writing, the only Alpha-based product currently available from DEC is the 21064 (EV4) processor chip; no system-level products can be ordered.  This port is provided for those developers who might have early Alpha hardware from DEC or other vendors and run the OSF/1 operating system.  It has not been extensively tested and both the C++ and Objective-C languages may not work, except in a cross-compilation environment.

          The ASSEMBLE_FILE_START macro writes a .verstamp directive containing the version of the calling sequence.  Currently, we use 9 0, which we believe will work until the official release by DEC of their system, at which point 3 11 is the correct value.  If you get a mismatch error from the assembler on a .verstamp line, consult the file /usr/include/stamp.h for the present value.  GNU C on the Alpha does not support versions of DEC's OSF/1 earlier than BL9; if you are running an older version, we suggest you ask your DEC contact for an update.

          Note that since the Alpha is a 64-bit architecture, cross-compilers from 32-bit machines will not generate as efficient code as that generated when the compiler is running on a 64-bit machine because many optimizations that depend on being able to represent a word on the target in an integral value on the host cannot be performed.

     a29k
          AMD Am29K-family processors.  These are normally used in embedded applications.  There are no standard Unix configurations. This configuration corresponds to AMD's standard calling sequence and binary interface and is compatible with other 29K tools.

          You may need to make a variant of the file a29k.h for your particular configuration.

     a29k-*-bsd
          AMD Am29050 used in a system running a variant of BSD Unix.

     elxsi-elxsi-bsd
          The Elxsi's C compiler has known limitations that prevent it from compiling GNU C.  Please contact mrs@cygnus.com for more details.

     i386-*-sco
          Compilation with RCC is recommended.

     i386-ibm-aix
          You need a version of GAS that you can get from tranle@intellicorp.com.

     i386-sequent
          Go to the Berkeley universe before compiling.  In addition, you probably need to create a file named string.h containing just one line: #include <strings.h>.

     i386-sun-sunos4
          You may find that you need another version of GNU CC to begin bootstrapping with, since the current version when built with the system's own compiler seems to get an infinite loop compiling part of libgcc2.c.  GNU CC version 2 compiled with GNU CC (any version) seems not to have this problem.

     m68000-att
          AT&T 3b1, a.k.a. 7300 PC.  Special procedures are needed to compile GNU CC with this machine's standard C compiler, due to bugs in that compiler.  See 3b1 Install.  You can bootstrap it more easily with previous versions of GNU CC if you have them.

     m68000-hp-bsd
          HP 9000 series 200 running BSD.  Note that the C compiler that comes with this system cannot compile GNU CC; contact law@cs.utah.edu to get binaries of GNU CC for bootstrapping.

     m68k-altos
          Altos 3068.  You must use the GNU assembler, linker and debugger, with COFF-encapsulation.  Also, you must fix a kernel bug.  Details in the file README.ALTOS.

     m68k-hp-hpux
          HP 9000 series 300 or 400 running HP-UX.  HP-UX version 8.0 has a bug in the assembler that prevents compilation of GNU CC.  To fix it, get patch PHCO_0800 from HP.

          In addition, --gas does not currently work with this configuration.  Changes in HP-UX have broken the library conversion tool and the linker.

     m68k-sun
          Sun 3.  We do not provide a configuration file to use the Sun FPA by default, because programs that establish signal handlers for floating point traps inherently cannot work with the FPA.

     m88k-svr3
          Motorola m88k running the AT&T/Unisoft/Motorola V.3 reference port. These systems tend to use the Green Hills C, revision 1.8.5, as the standard C compiler.  There are apparently bugs in this compiler that result in object files differences between stage 2 and stage 3.  If this happens, make the stage 4 compiler and compare it to the stage 3 compiler.  If the stage 3 and stage 4 object files are identical, this suggests a problem with the standard C compiler.  It is best, however, to use an older version of GNU CC for bootstrapping.

     m88k-dgux
          Motorola m88k running DG/UX.  To build native or cross compilers on DG/UX, you must first change to the 88open BCS software development environment.  This is done by issuing this command:

               eval `sde-target m88kbcs`

     mips-mips-bsd
          MIPS machines running the MIPS operating system in BSD mode.  It's possible that some old versions of the system lack the functions memcpy, memcmp, and memset.  If your system lacks these, you must remove or undo the definition of TARGET_MEM_FUNCTIONS in mips-bsd.h.

     mips-sony-sysv
          Sony MIPS NEWS.  This works in NEWSOS 5.0.1, but not in 5.0.2 (which uses ELF instead of COFF).  Support for 5.0.2 will probably be provided soon by volunteers.

     ns32k-encore
          Encore ns32000 system.  Encore systems are supported only under BSD.

     ns32k-*-genix
          National Semiconductor ns32000 system.  Genix has bugs in alloca and malloc; you must get the compiled versions of these from GNU Emacs.

     ns32k-sequent
          Go to the Berkeley universe before compiling.  In addition, you probably need to create a file named string.h containing just one line: #include <strings.h>.

     ns32k-utek
          UTEK ns32000 system (``merlin'').  The C compiler that comes with this system cannot compile GNU CC; contact tektronix!reed!mason to get binaries of GNU CC for bootstrapping.

     romp-*-aos
     romp-*-mach
          The only operating systems supported for the IBM RT PC are AOS and MACH.  GNU CC does not support AIX running on the RT.  We recommend you compile GNU CC with an earlier version of itself; if you compile GNU CC with hc, the Metaware compiler, it will work, but you will get mismatches between the stage 2 and stage 3 compilers in various files. These errors are minor differences in some floating-point constants and can be safely ignored; the stage 3 compiler is correct.

     rs6000-*-aix
          Read the file README.RS6000 for information on how to get a fix for a problem in the IBM assembler that prevents use of GNU CC. You must either obtain the new assembler or avoid using the -g switch.  Note that Makefile.in uses -g by default when compiling libgcc2.c.

     vax-dec-ultrix
          Don't try compiling with Vax C (vcc).  It produces incorrect code in some cases (for example, when alloca is used).

          Meanwhile, compiling cp-parse.c with pcc does not work because of an internal table size limitation in that compiler.  To avoid this problem, compile just the GNU C compiler first, and use it to recompile building all the languages that you want to run.

     Here we spell out what files will be set up by configure.  Normally you need not be concerned with these files.

       * A symbolic link named config.h is made to the top-level config file for the machine you plan to run the compiler on (see The Configuration File (Using and Porting GCC)).  This file is responsible for defining information about the host machine.  It includes tm.h.

          The top-level config file is located in the subdirectory config. Its name is always xm-SOMETHING.h; usually xm-MACHINE.h, but there are some exceptions.

          If your system does not support symbolic links, you might want to set up config.h to contain a #include command which refers to the appropriate file.

       * A symbolic link named tconfig.h is made to the top-level config file for your target machine.  This is used for compiling certain programs to run on that machine.

       * A symbolic link named tm.h is made to the machine-description macro file for your target machine.  It should be in the subdirectory config and its name is often MACHINE.h.

       * A symbolic link named md will be made to the machine description pattern file.  It should be in the config subdirectory and its name should be MACHINE.md; but MACHINE is often not the same as the name used in the tm.h file because the md files are more general.

       * A symbolic link named aux-output.c will be made to the output subroutine file for your machine.  It should be in the config subdirectory and its name should be MACHINE.c.

       * The command file configure also constructs Makefile by adding some text to the template file Makefile.in.  The additional text comes from files in the config directory, named t-TARGET and h-HOST.  If these files do not exist, it means nothing needs to be added for a given target or host.

 4. Make sure the Bison parser generator is installed.  (This is unnecessary if the Bison output files c-parse.c and cexp.c are more recent than c-parse.y and cexp.y and you do not plan to change the .y files.)

     Bison versions older than Sept 8, 1988 will produce incorrect output for c-parse.c.

 5. Build the compiler.  Just type make LANGUAGES=c in the compiler directory.

     LANGUAGES=c specifies that only the C compiler should be compiled.  The makefile normally builds compilers for all the supported languages; currently, C, C++ and Objective C.  However, C is the only language that is sure to work when you build with other non-GNU C compilers.  In addition, building anything but C at this stage is a waste of time.

     In general, you can specify the languages to build by typing the argument LANGUAGES="LIST", where LIST is one or more words from the list c, c++, and objective-c.

     Ignore any warnings you may see about ``statement not reached'' in insn-emit.c; they are normal.  Any other compilation errors may represent bugs in the port to your machine or operating system, and should be investigated and reported (see Bugs).

     Some commercial compilers fail to compile GNU CC because they have bugs or limitations.  For example, the Microsoft compiler is said to run out of macro space.  Some Ultrix compilers run out of expression space; then you need to break up the statement where the problem happens.

     If you are building with a previous GNU C compiler, do not use CC=gcc on the make command or by editing the Makefile. Instead, use a full pathname to specify the compiler, such as CC=/usr/local/bin/gcc.  This is because make might execute the gcc in the current directory before all of the compiler components have been built.

 6. If you are using COFF-encapsulation, you must convert libgcc.a to a GNU-format library at this point.  See the file README.ENCAP in the directory containing the GNU binary file utilities, for directions.

 7. If you are building a cross-compiler, stop here.  See Cross-Compiler.

 8. Move the first-stage object files and executables into a subdirectory with this command:

          make stage1

     The files are moved into a subdirectory named stage1. Once installation is complete, you may wish to delete these files with rm -r stage1.

 9. Recompile the compiler with itself, with this command:

          make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O"

     This is called making the stage 2 compiler.

     The command shown above builds compilers for all the supported languages.  If you don't want them all, you can specify the languages to build by typing the argument LANGUAGES="LIST".  LIST should contain one or more words from the list c, c++, objective-c, and proto.  Separate the words with spaces. proto stands for the programs protoize and unprotoize; they are not a separate language, but you use LANGUAGES to enable or disable their installation.

     If you are going to build the stage 3 compiler, then you might want to build only the C language in stage 2.

     Once you have built the stage 2 compiler, if you are short of disk space, you can delete the subdirectory stage1.

     On a 68000 or 68020 system lacking floating point hardware, unless you have selected a tm.h file that expects by default that there is no such hardware, do this instead:

          make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O -msoft-float"

 10. If you wish to test the compiler by compiling it with itself one more time, do this:

          make stage2
          make CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O"

     This is called making the stage 3 compiler.  Aside from the -B option, the compiler options should be the same as when you made the stage 2 compiler.  But the LANGUAGES option need not be the same.  The command shown above builds compilers for all the supported languages; if you don't want them all, you can specify the languages to build by typing the argument LANGUAGES="LIST", as described above.

     Then compare the latest object files with the stage 2 object files---they ought to be identical, unless they contain time stamps. You can compare the files, disregarding the time stamps if any, like this:

          make compare

     This will mention any object files that differ between stage 2 and stage 3.  Any difference, no matter how innocuous, indicates that the stage 2 compiler has compiled GNU CC incorrectly, and is therefore a potentially serious bug which you should investigate and report (see Bugs).

     If your system does not put time stamps in the object files, then this is a faster way to compare them (using the Bourne shell):

          for file in *.o; do
          cmp $file stage2/$file
          done

     If you have built the compiler with the -mno-mips-tfile option on MIPS machines, you will not be able to compare the files.

 11. Install the compiler driver, the compiler's passes and run-time support. You can use the following command:

          make install CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O" LANGUAGES="LIST"

     (Use the same value for CC, CFLAGS and LANGUAGES that you used when compiling the files that are being installed.  One reason this is necessary is that some versions of Make have bugs and recompile files gratuitously when you do this step.  If you use the same variable values, those files will be recompiled properly.

     This copies the files cc1, cpp and libgcc.a to files cc1, cpp and libgcc.a in directory /usr/local/lib/gcc-lib/TARGET/VERSION, which is where the compiler driver program looks for them.  Here TARGET is the target machine type specified when you ran configure, and VERSION is the version number of GNU CC.  This naming scheme permits various versions and/or cross-compilers to coexist.

     It also copies the driver program gcc into the directory /usr/local/bin, so that it appears in typical execution search paths.

     On some systems, this command will cause recompilation of some files. This is usually due to bugs in make.  You should either ignore this problem, or use GNU Make.

     Warning: there is a bug in alloca in the Sun library.  To avoid this bug, be sure to install the executables of GNU CC that were compiled by GNU CC.  (That is, the executables from stage 2 or 3, not stage 1.)  They use alloca as a built-in function and never the one in the library.

     (It is usually better to install GNU CC executables from stage 2 or 3, since they usually run faster than the ones compiled with some other compiler.)

 12. Install the Objective C library (if you have built the Objective C compiler).  Here is the command to do this:

          make install-libobjc CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O"

 13. Correct errors in the header files on your machine.

     Various system header files often contain constructs which are erroneous, incompatible with ANSI C or otherwise unsuitable, and they will not work when you compile programs with GNU CC.

     The most common erroneous construct is found in ioctl.h, where a macro expects argument values to be substituted for argument names inside of character constants---something not done in ANSI C.  This particular problem can be prevented by using -traditional.  Other problems are not so easy to work around.

     GNU CC comes with shell scripts to fix known header file problems.  They install corrected copies of various header files in a special directory where only GNU CC will normally look for them.  The scripts adapt to various systems by searching all the system header files for the problem cases that we know about.

     Use the following command to do this:

          make install-fixincludes

     If you selected a different directory for GNU CC installation when you installed it, by specifying the Make variable prefix or libdir, specify it the same way in this command.

     Note that some systems are starting to come with ANSI C system header files.  On these systems, don't run install-fixincludes; it may not work, and is certainly not necessary.  One exception: there are is a special script for System V release 4, which you should run.

     It is not the purpose of install-fixincludes to add prototypes to the system header files.  We support headers with ANSI C prototypes in the GNU C Library, and we have no time to support adding them to other systems' header files.

 14. If you're going to use C++, it's likely that you need to also install the libg++ distribution.  It should be available from the same place where you got the GCC distribution.  Just as GCC does not distribute a C runtime library, it also does not include a C++ run-time library.  All I/O functionality, special class libraries, etc., are available in the libg++ distribution.

If you cannot install the compiler's passes and run-time support in /usr/local/lib, you can alternatively use the -B option to specify a prefix by which they may be found.  The compiler concatenates the prefix with the names  cpp, cc1 and libgcc.a. Thus, you can put the files in a directory /usr/foo/gcc and specify -B/usr/foo/gcc/ when you run GNU CC.

Also, you can specify an alternative default directory for these files by setting the Make variable libdir when you make GNU CC.

Compilation in a Separate Directory
===================================

If you wish to build the object files and executables in a directory other than the one containing the source files, here is what you must do differently:

 1. Make sure you have a version of Make that supports the VPATH feature.  (GNU Make supports it, as do Make versions on most BSD systems.)

 2. If you have ever run configure in the source directory, you must undo the configuration.  Do this by running:

          make distclean

 3. Go to the directory in which you want to build the compiler before running configure:

          mkdir gcc-sun3
          cd gcc-sun3

     On systems that do not support symbolic links, this directory must be on the same file system as the source code directory.

 4. Specify where to find configure when you run it:

          ../gcc/configure ...

     This also tells configure where to find the compiler sources; configure takes the directory from the file name that was used to invoke it.  But if you want to be sure, you can specify the source directory with the --srcdir option, like this:

          ../gcc/configure --srcdir=../gcc sun3

     The directory you specify with --srcdir need not be the same as the one that configure is found in.

Now, you can run make in that directory.  You need not repeat the configuration steps shown above, when ordinary source files change.  You must, however, run configure again when the configuration files change, if your system does not support symbolic links.

Building and Installing a Cross-Compiler
========================================

GNU CC can function as a cross-compiler for many machines, but not all.

  * Cross-compilers for the Mips as target do not work because the auxiliary programs mips-tdump.c and mips-tfile.c can't be compiled on anything but a Mips.

  * Cross-compilers to or from the Vax probably don't work completely because the Vax uses an incompatible floating point format (not IEEE format).

Since GNU CC generates assembler code, you probably need a cross-assembler that GNU CC can run, in order to produce object files. If you want to link on other than the target machine, you need a cross-linker as well.  You also need header files and libraries suitable for the target machine that you can install on the host machine.

To build GNU CC as a cross-compiler, you start out by running configure.  You must specify two different configurations, the host and the target.  Use the --host=HOST option for the host and --target=TARGET to specify the target type.  For example, here is how to configure for a cross-compiler that runs on a hypothetical Intel 386 system and produces code for an HP 68030 system running BSD:

     configure --target=m68k-hp-bsd4.3 --host=i386-bozotheclone-bsd4.3

Next you should install the cross-assembler and cross-linker (and ar and ranlib).  Put them in the directory /usr/local/TARGET/bin.  The installation of GNU CC will find them there and copy or link them to the proper place to find them when you run the cross-compiler later.

If you want to install any additional libraries to use with the cross-compiler, put them in the directory /usr/local/TARGET/lib; all files in that subdirectory will be installed in the proper place when you install the cross-compiler. Likewise, put the header files for the target machine in /usr/local/TARGET/include.

You must now produce a substitute for libgcc1.a.  Normally this file is compiled with the ``native compiler'' for the target machine; compiling it with GNU CC does not work.  But compiling it with the host machine's compiler also doesn't work---that produces a file that would run on the host, and you need it to run on the target.

We can't give you any automatic way to produce this substitute.  For some targets, the subroutines in libgcc1.c are not actually used. You need not provide the ones that won't be used.  The ones that most commonly are used are the multiplication, division and remainder routines---many RISC machines rely on the library for this.  One way to make them work is to define the appropriate perform_... macros for the subroutines that you need.  If these definitions do not use the C arithmetic operators that they are meant to implement, you might be able to compile them with the cross-compiler you are building. To do this, specify LIBGCC1=libgcc1.a OLDCC=./xgcc when building the compiler.

Now you can proceed just as for compiling a single-machine compiler through the step of building stage 1.  If you have not provided some sort of libgcc1.a, then compilation will give up at the point where it needs that file, printing a suitable error message.  If you do provide libgcc1.a, then building the compiler will automatically compile and link a test program called cross-test; if you get errors in the linking, it means that not all of the necessary routines in libgcc1.a are available.

When you are using a cross-compiler configuration, building stage 1 does not compile all of GNU CC.  This is because one part of building, the compilation of libgcc2.c, requires use of the cross-compiler.

However, when you type make install to install the bulk of the cross-compiler, that will also compile libgcc2.c and install the resulting libgcc.a.

Do not try to build stage 2 for a cross-compiler.  It doesn't work to rebuild GNU CC as a cross-compiler using the cross-compiler, because that would produce a program that runs on the target machine, not on the host.  For example, if you compile a 386-to-68030 cross-compiler with itself, the result will not be right either for the 386 (because it was compiled into 68030 code) or for the 68030 (because it was configured for a 386 as the host).  If you want to compile GNU CC into 68030 code, whether you compile it on a 68030 or with a cross-compiler on a 386, you must specify a 68030 as the host when you configure it.

Installing GNU CC on the HP Precision Architecture
==================================================

There are two variants of this CPU, called 1.0 and 1.1, which have different machine descriptions.  You must use the right one for your machine.  All 7NN machines and 8N7 machines use 1.1, while all other 8NN machines use 1.0.

The easiest way to handle this problem is to use configure hpNNN or configure hpNNN-hpux, where NNN is the model number of the machine.  Then configure will figure out if the machine is a 1.0 or 1.1.  Use uname -a to find out the model number of your machine.

-g does not work on HP-UX, since that system uses a peculiar debugging format which GNU CC does not know about.  There are preliminary versions of GAS and GDB for the HP-PA which do work with GNU CC for debugging.  You can get them by anonymous ftp from jaguar.cs.utah.edu dist subdirectory.  You would need to install GAS in the file

     /usr/local/lib/gcc-lib/CONFIGURATION/GCCVERSION/as

where CONFIGURATION is the configuration name (perhaps hpNNN-hpux) and GCCVERSION is the GNU CC version number.  Do this before starting the build process, otherwise you will get errors from the HPUX assembler while building libgcc2.a.  The command

     make install-dir

will create the necessary directory hierarchy so you can install GAS before building GCC.

If you obtained GAS before October 6, 1992 it is highly recommended you get a new one to avoid several bugs which have been discovered recently.

To enable debugging, configure GNU CC with the --gas option before building.

Installing GNU CC on the Sun
============================

Make sure the environment variable FLOAT_OPTION is not set when you compile libgcc.a.  If this option were set to f68881 when libgcc.a is compiled, the resulting code would demand to be linked with a special startup file and would not link properly without special pains.

There is a bug in alloca in certain versions of the Sun library. To avoid this bug, install the binaries of GNU CC that were compiled by GNU CC.  They use alloca as a built-in function and never the one in the library.

Some versions of the Sun compiler crash when compiling GNU CC.  The problem is a segmentation fault in cpp.  This problem seems to be due to the bulk of data in the environment variables.  You may be able to avoid it by using the following command to compile GNU CC with Sun CC:

     make CC="TERMCAP=x OBJS=x LIBFUNCS=x STAGESTUFF=x cc"

Installing GNU CC on the 3b1
============================

Installing GNU CC on the 3b1 is difficult if you do not already have GNU CC running, due to bugs in the installed C compiler.  However, the following procedure might work.  We are unable to test it.

 1. Comment out the #include "config.h" line on line 37 of cccp.c and do make cpp.  This makes a preliminary version of GNU cpp.

 2. Save the old /lib/cpp and copy the preliminary GNU cpp to that file name.

 3. Undo your change in cccp.c, or reinstall the original version, and do make cpp again.

 4. Copy this final version of GNU cpp into /lib/cpp.

 5. Replace every occurrence of obstack_free in the file tree.c with _obstack_free.

 6. Run make to get the first-stage GNU CC.

 7. Reinstall the original version of /lib/cpp.

 8. Now you can compile GNU CC with itself and install it in the normal fashion.

Installing GNU CC on Unos
=========================

Use configure unos for building on Unos.

The Unos assembler is named casm instead of as.  For some strange reason linking /bin/as to /bin/casm changes the behavior, and does not work.  So, when installing GNU CC, you should install the following script as as in the subdirectory where the passes of GCC are installed:

     #!/bin/sh
     casm $*

The default Unos library is named libunos.a instead of libc.a.  To allow GNU CC to function, either change all references to -lc in gcc.c to -lunos or link /lib/libc.a to /lib/libunos.a.

When compiling GNU CC with the standard compiler, to overcome bugs in the support of alloca, do not use -O when making stage 2. Then use the stage 2 compiler with -O to make the stage 3 compiler.  This compiler will have the same characteristics as the usual stage 2 compiler on other systems.  Use it to make a stage 4 compiler and compare that with stage 3 to verify proper compilation.

(Perhaps simply defining ALLOCA in x-crds as described in the comments there will make the above paragraph superfluous.  Please inform us of whether this works.)

Unos uses memory segmentation instead of demand paging, so you will need a lot of memory.  5 Mb is barely enough if no other tasks are running. If linking cc1 fails, try putting the object files into a library and linking from that library.

Installing GNU CC on VMS
========================

The VMS version of GNU CC is distributed in a backup saveset containing both source code and precompiled binaries.

To install the gcc command so you can use the compiler easily, in the same manner as you use the VMS C compiler, you must install the VMS CLD file for GNU CC as follows:

 1. Define the VMS logical names GNU_CC and GNU_CC_INCLUDE to point to the directories where the GNU CC executables (gcc-cpp.exe, gcc-cc1.exe, etc.) and the C include files are kept respectively.  This should be done with the commands:

          $ assign /system /translation=concealed -
            disk:[gcc.] gnu_cc
          $ assign /system /translation=concealed -
            disk:[gcc.include.] gnu_cc_include

     with the appropriate disk and directory names.  These commands can be placed in your system startup file so they will be executed whenever the machine is rebooted.  You may, if you choose, do this via the GCC_INSTALL.COM script in the [GCC] directory.

 2. Install the GCC command with the command line:

          $ set command /table=sys$common:[syslib]dcltables -
            /output=sys$common:[syslib]dcltables gnu_cc:[000000]gcc
          $ install replace sys$common:[syslib]dcltables

 3. To install the help file, do the following:

          $ library/help sys$library:helplib.hlb gcc.hlp

     Now you can invoke the compiler with a command like gcc /verbose file.c, which is equivalent to the command gcc -v -c file.c in Unix.

If you wish to use GNU C++ you must first install GNU CC, and then perform the following steps:

 1. Define the VMS logical name GNU_GXX_INCLUDE to point to the directory where the preprocessor will search for the C++ header files. This can be done with the command:

          $ assign /system /translation=concealed -
            disk:[gcc.gxx_include.] gnu_gxx_include

     with the appropriate disk and directory name.  If you are going to be using libg++, this is where the libg++ install procedure will install the libg++ header files.

 2. Obtain the file gcc-cc1plus.exe, and place this in the same directory that gcc-cc1.exe is kept.

     The GNU C++ compiler can be invoked with a command like gcc /plus /verbose file.cc, which is equivalent to the command g++ -v -c file.cc in Unix.

We try to put corresponding binaries and sources on the VMS distribution tape.  But sometimes the binaries will be from an older version than the sources, because we don't always have time to update them.  (Use the /version option to determine the version number of the binaries and compare it with the source file version.c to tell whether this is so.)  In this case, you should use the binaries you get to recompile the sources.  If you must recompile, here is how:

 1. Execute the command procedure vmsconfig.com to copy files vax-vms.h, xm-vax-vms.h, vax.c and vax.md to tm.h, config.h, aux-output.c, and md. respectively, and to create files tconfig.h and hconfig.h.  This procedure also creates several linker option files used by make-cc1.com and a data file used by make-l2.com.

          $ @vmsconfig.com

 2. Setup the logical names and command tables as defined above.  In addition, define the VMS logical name GNU_BISON to point at the to the directories where the Bison executable is kept.  This should be done with the command:

          $ assign /system /translation=concealed -
            disk:[bison.] gnu_bison

     You may, if you choose, use the INSTALL_BISON.COM script in the [BISON] directory.

 3. Install the BISON command with the command line:

          $ set command /table=sys$common:[syslib]dcltables -
            /output=sys$common:[syslib]dcltables -
            gnu_bison:[000000]bison
          $ install replace sys$common:[syslib]dcltables

 4. Type @make-gcc to recompile everything (alternatively, you may submit the file make-gcc.com to a batch queue).  If you wish to build the GNU C++ compiler as well as the GNU CC compiler, you must first edit make-gcc.com and follow the instructions that appear in the comments.

 5. In order to use GCC, you need a library of functions which GCC compiled code will call to perform certain tasks, and these functions are defined in the file libgcc2.c.  To compile this you should use the command procedure make-l2.com, which will generate the library libgcc2.olb. libgcc2.olb should be built using the compiler built from the same distribution that libgcc2.c came from, and make-gcc.com will automatically do all of this for you.

     To install the library, use the following commands:

          $ library gnu_cc:[000000]gcclib/delete=(new,eprintf)
          $ library libgcc2/extract=*/output=libgcc2.obj
          $ library gnu_cc:[000000]gcclib libgcc2.obj

     The first command simply removes old modules that will be replaced with modules from libgcc2.  If the VMS librarian complains about those modules not being present, simply ignore the message and continue on with the next command.

     Whenever you update the compiler on your system, you should also update the library with the above procedure.

 6. You may wish to build GCC in such a way that no files are written to the directory where the source files reside.  An example would be the when the source files are on a read-only disk.  In these cases, execute the following DCL commands (substituting your actual path names):

          $ assign dua0:[gcc.build_dir.]/translation=concealed, -
                   dua1:[gcc.source_dir.]/translation=concealed  gcc_build
          $ set default gcc_build:[000000]

     where dua1:[gcc.source_dir] contains the source code, and dua0:[gcc.build_dir] is meant to contain all of the generated object files and executables.  Once you have done this, you can proceed building GCC as described above.  (Keep in mind that gcc_build is a rooted logical name, and thus the device names in each element of the search list must be an actual physical device name rather than another rooted logical name).

 7. If you are building GNU CC with a previous version of GNU CC, you also should check to see that you have the newest version of the assembler.  In particular, GNU CC version 2 treats global constant variables slightly differently from GNU CC version 1, and GAS version 1.38.1 does not have the patches required to work with GCC version 2. If you use GAS 1.38.1, then extern const variables will not have the read-only bit set, and the linker will generate warning messages about mismatched psect attributes for these variables.  These warning messages are merely a nuisance, and can safely be ignored.

     If you are compiling with a version of GNU CC older than 1.33, specify /DEFINE=("inline=") as an option in all the compilations.  This requires editing all the gcc commands in make-cc1.com. (The older versions had problems supporting inline.)  Once you have a working 1.33 or newer GNU CC, you can change this file back.

 8. If you want to build GNU CC with the VAX C compiler, you will need to make minor changes in make-cccp.com and make-cc1.com to choose alternate definitions of CC, CFLAGS, and LIBS.  See comments in those files.  However, you must also have a working version of the GNU assembler (GNU as, aka GAS) as it is used as the back-end for GNU CC to produce binary object modules and is not included in the GNU CC sources.  GAS is also needed to compile libgcc2 in order to build gcclib (see above); make-l2.com expects to be able to find it operational in gnu_cc:[000000]gnu-as.exe.

     To use GNU CC on VMS, you need the VMS driver programs gcc.exe, gcc.com, and gcc.cld.  They are distributed with the VMS binaries (gcc-vms) rather than the GNU CC sources.  GAS is also included in gcc-vms, as is Bison.

     Once you have successfully built GNU CC with VAX C, you should use the resulting compiler to rebuild itself.  Before doing this, be sure to restore the CC, CFLAGS, and LIBS definitions in make-cccp.com and make-cc1.com.  The second generation compiler will be able to take advantage of many optimizations that must be suppressed when building with other compilers.

Under previous versions of GNU CC, the generated code would occasionally give strange results when linked with the sharable VAXCRTL library. Now this should work.

Even with this version, however, GNU CC itself should not be linked with the sharable VAXCRTL.  The version of qsort in VAXCRTL has a bug (known to be present in VMS versions V4.6 through V5.5) which causes the compiler to fail.

The executables that are generated by make-cc1.com and make-cccp.com use the object library version of VAXCRTL in order to make use of the qsort routine in gcclib.olb.  If you wish to link the compiler executables with the shareable image version of VAXCRTL, you should edit the file tm.h (created by vmsconfig.com) to define the macro QSORT_WORKAROUND.

QSORT_WORKAROUND is always defined when GNU CC is compiled with VAX C, to avoid a problem in case gcclib.olb is not yet available.

Installing GNU CC on the WE32K
==============================

These computers are also known as the 3b2, 3b5, 3b20 and other similar names.  (However, the 3b1 is actually a 68000; see 3b1 Install.)

Don't use -g when compiling with the system's compiler.  The system's linker seems to be unable to handle such a large program with debugging information.

The system's compiler runs out of capacity when compiling stmt.c in GNU CC.  You can work around this by building cpp in GNU CC first, then use that instead of the system's preprocessor with the system's C compiler to compile stmt.c.  Here is how:

     mv /lib/cpp /lib/cpp.att
     cp cpp /lib/cpp.gnu
     echo "/lib/cpp.gnu -traditional $*" > /lib/cpp
     chmod +x /lib/cpp

The system's compiler produces bad code for some of the GNU CC optimization files.  So you must build the stage 2 compiler without optimization.  Then build a stage 3 compiler with optimization. That executable should work.  Here are the necessary commands:

     make LANGUAGES=c CC=stage1/xgcc CFLAGS="-Bstage1/ -g"
     make stage2
     make CC=stage2/xgcc CFLAGS="-Bstage2/ -g -O"

You may need to raise the ULIMIT setting to build a C++ compiler, as the file cc1plus is larger than one megabyte.

Installing GNU CC on the MIPS
=============================

See Installation about whether to use --with-stabs or not.

The MIPS C compiler needs to be told to increase its table size for switch statements with the -Wf,-XNg1500 option in order to compile cp-parse.c.  If you use the -O2 optimization option, you also need to use -Olimit 3000. Both of these options are automatically generated in the Makefile that the shell script configure builds. If you override the CC make variable and use the MIPS compilers, you may need to add -Wf,-XNg1500 -Olimit 3000.

MIPS computers running RISC-OS can support four different personalities: default, BSD 4.3, System V.3, and System V.4 (older versions of RISC-OS don't support V.4).  To configure GCC for these platforms use the following configurations:

mips-mips-riscosrev
     Default configuration for RISC-OS, revision rev.

mips-mips-riscosrevbsd
     BSD 4.3 configuration for RISC-OS, revision rev.

mips-mips-riscosrevsysv4
     System V.4 configuration for RISC-OS, revision rev.

mips-mips-riscosrevsysv
     System V.3 configuration for RISC-OS, revision rev.

The revision rev mentioned above is the revision of RISC-OS to use.  You must reconfigure GCC when going from a RISC-OS revision 4 to RISC-OS revision 5.  This has the effect of avoiding a linker bug (see Installation Problems for more details).

DECstations can support three different personalities: Ultrix, DEC OSF/1, and OSF/rose.  To configure GCC for these platforms use the following configurations:

decstation-ultrix
     Ultrix configuration.

decstation-osf1
     Dec's version of OSF/1.

decstation-osfrose
     Open Software Foundation reference port of OSF/1 which uses the OSF/rose object file format instead of ECOFF.  Normally, you would not select this configuration.