Copyright © 2001 Free Software Foundation, Inc.

Installing GCC
**************

The latest version of this document is always available at http://gcc.gnu.org/install/.

This document describes the generic installation procedure for GCC as well as detailing some target specific installation instructions.

GCC includes several components that previously were separate distributions with their own installation instructions. This document supersedes all package specific installation instructions. We provide the component specific installation information in the source distribution for historical reference purposes only.

Before starting the build/install procedure please check the See host/target specific installation notes. We recommend you browse the entire generic installation instructions before you proceed.

The installation procedure itself is broken into five steps.

Please note that GCC does not support make uninstall and probably won't do so in the near future as this would open a can of worms. Instead, we suggest that you install GCC into a directory of its own and simply remove that directory when you do not need that specific version of GCC any longer.

Downloading GCC
***************

GCC is distributed via CVS and FTP tarballs compressed with gzip or bzip2. It is possible to download a full distribution or specific components.

Please refer to our releases web page for information on how to obtain GCC.

The full distribution includes the C, C++, Objective-C, Fortran, Java, and Chill compilers.  The full distribution also includes runtime libraries for C++, Objective-C and Fortran.  In the future the GNU compiler testsuites will be included in the full distribution.

If you choose to download specific components, you must download the core gcc distribution plus any language specific distributions you wish to use.  The core distribution includes the C language front-end as well as the shared components. Each language has a tarball which includes the language front-end as well as the language runtime (when appropriate).

Unpack the core distribution as well as any language specific distributions in the same directory.

If you also intend to build binutils (either to upgrade an existing installation or for use in place of the corresponding tools of your OS), unpack the binutils distribution either in the same directory or a separate one.  In the latter case, add symbolic links to any components of the binutils you intend to build alongside the compiler (bfd, binutils, gas, gprof, ld, opcodes,...) to the directory containing the GCC sources.

Installing GCC: Configuration
*****************************

Like most GNU software, GCC must be configured before it can be built. This document describes the recommended configuration procedure for both native and cross targets.

We use SRCDIR to refer to the toplevel source directory for GCC; we use OBJDIR to refer to the toplevel build/object directory.

If you obtained the sources via CVS, SRCDIR must refer to the top gcc directory, the one where the MAINTAINERS can be found, and not its gcc subdirectory, otherwise the build will fail.

First, we highly recommend that GCC be built into a separate directory than the sources which does not reside within the source tree.  This is how we generally build GCC; building where SRCDIR == OBJDIR should still work, but doesn't get extensive testing; building where OBJDIR is a subdirectory of SRCDIR is unsupported.

Second, when configuring a native system, either cc or gcc must be in your path or you must set CC in your environment before running configure.  Otherwise the configuration scripts may fail.

To configure GCC:

        % mkdir OBJDIR
        % cd OBJDIR
        % SRCDIR/configure [target] [options]

target specification

  * GCC has code to correctly determine the correct value for TARGET for nearly all native systems.  Therefore, we highly recommend you not provide a configure target when configuring a native compiler.

  * TARGET must be specified as --target=TARGET when configuring a cross compiler; examples of valid targets would be i960-rtems, m68k-coff, sh-elf, etc.

  * Specifying just TARGET instead of --target=TARGET implies that the host defaults to TARGET.

options specification

Use options to override several configure time options for GCC.  A partial list of supported options:

  * --prefix=DIRNAME -- Specify the toplevel installation directory.  This is the recommended way to install the tools into a directory other than the default.  The toplevel installation directory defaults to /usr/local.

     We highly recommend against DIRNAME being the same or a subdirectory of OBJDIR or vice versa.

     These additional options control where certain parts of the distribution are installed.  Normally you should not need to use these options.

       * --with-gxx-include-dir=DIRNAME -- Specify the installation directory for g++ header files.  The default is /usr/local/include/g++.

  * --with-local-prefix=DIRNAME -- Specify the installation directory for local include files.  The default is /usr/local.  Specify this option if you want the compiler to search directory DIRNAME/include for locally installed header files instead of /usr/local/include.

     You should specify --with-local-prefix only if your site has a different convention (not /usr/local) for where to put site-specific files.

     The default value for --with-local-prefix is /usr/local regardless of the value of --prefix.  Specifying --prefix has no effect on which directory GCC searches for local header files.  This may seem counterintuitive, but actually it is logical.

     The purpose of --prefix is to specify where to install GCC.  The local header files in /usr/local/include---if you put any in that directory---are not part of GCC.  They are part of other programs---perhaps many others.  (GCC installs its own header files in another directory which is based on the --prefix value.)

     Do not specify /usr as the --with-local-prefix! The directory you use for --with-local-prefix must not contain any of the system's standard header files.  If it did contain them, certain programs would be miscompiled (including GNU Emacs, on certain targets), because this would override and nullify the header file corrections made by the fixincludes script.

     Indications are that people who use this option use it based on mistaken ideas of what it is for.  People use it as if it specified where to install part of GCC.  Perhaps they make this assumption because installing GCC creates the directory.

  * --enable-shared -- Build shared versions of the C++ runtime libraries if supported. This is the default on most systems. Use --disable-shared for static libraries. Note that up to the gcc version 2.95.x series, static libraries were the default on all systems.

  * -- Specify that the compiler should assume that the assembler it finds is the GNU assembler. However, this does not modify the rules to find an assembler and will result in confusion if found assembler is not actually the GNU assembler.  If you have more than one assembler installed on your system, you may want to use this option in connection with --with-as=/path/to/gas.

  * --with-as=/path/to/as -- Specify that the compiler should use the assembler pointed to by PATHNAME, rather than the one found by the standard rules to find an assembler, which are:

       * Check the EXEC_PREFIX/lib/gcc-lib/TARGET/VERSION directory, where EXEC_PREFIX defaults to PREFIX which defaults to /usr/local unless overridden by the --prefix=/pathname switch described above. TARGET is the target system triple, such as SPARC-SUN-SOLARIS2.7, and VERSION denotes the GCC version, such as 2.95.2.

       * Check operating system specific directories (e.g. /usr/ccs/bin on Sun Solaris).

     Note that these rules do not check for the value of PATH. You may want to use --with-as if no assembler is installed in the directories listed above, or if you have multiple assemblers installed and want to choose one that is not found by the above rules.

  * -- Same as --with-gnu-as but for linker.

  * --with-ld=/path/to/ld -- Same as --with-as, but for the linker.

  * --with-stabs -- Specify that stabs debugging information should be used instead of whatever format the host normally uses.  Normally GCC uses the same debug format as the host system.

  * --enable-multilib -- Specify that multiple target libraries should be built to support different target variants, calling conventions, etc.  This is the default.

  * --enable-threads -- Specify that the target supports threads.  This affects the Objective-C compiler and runtime library, and exception handling for other languages like C++ and Java. On some systems, this is the default.

  * --enable-threads=LIB -- Specify that LIB is the thread support library.  This affects the Objective-C compiler and runtime library, and exception handling for other languages like C++ and Java.  The possibilities for LIB are aix, dce, decosf1, irix, mach, os2, posix, pthreads, single, solaris, vxworks and win32.

  * --with-cpu=CPU -- Specify which cpu variant the compiler should generate code for by default.  This is currently only supported on the some ports, specifically arm, powerpc, and SPARC. If configure does not recognize the model name (e.g. arm700, 603e, or ultrasparc) you provide, please check the configure script for a complete list of supported models.

  * --enable-target-optspace -- Specify that target libraries should be optimized for code space instead of code speed. This is the default for the m32r platform.

  * --enable-cpp -- Specify that a shell script which emulates traditional cpp functionality should be installed.

  * --enable-cpplib -- Specify that the functionality of CPP should be integrated into the compiler itself.  This option is not supported by snapshots since November 2000.  In snapshots where it is supported, it is not enabled by default, except for snapshots very close to November 2000.

  * --enable-maintainer-mode -- The build rules that regenerate the GCC master message catalog gcc.pot are normally disabled. This is because it can only be rebuilt if the complete source tree is present. If you have changed the sources and want to rebuild the catalog, configuring with --enable-maintainer-mode will enable this. Note that you need a recent version of the gettext tools to do so.

  * --without-fast-fixincludes -- Specify that the old, slower method of fixing the system header files should be used. EGCS 1.1.x and older releases default to the slow version. GCC 2.95 and newer releases will default to the fast version.

  * --enable-version-specific-runtime-libs -- Specify that runtime libraries should be installed in the compiler specific subdirectory (LIBSUBDIR) rather than the usual places.  In addition, libstdc++'s include files will be installed in LIBSUBDIR/include/g++ unless you overruled it by using --with-gxx-include-dir=DIRNAME.  Using this option is particularly useful if you intend to use several versions of GCC in parallel. This is currently supported by libf2c and libstdc++.

  * --enable-languages=LANG1,LANG2,... -- Specify that only a particular subset of compilers and their runtime libraries should be built. For a list of valid values for LANGx you can issue the following command in the gcc directory of your GCC source tree:
      grep language=
     */config-lang.in
      Currently, you can use any of the following: c++, f77, java and objc. CHILL is not currently maintained, and will almost certainly fail to compile.  Note that this switch does not work with EGCS 1.1.2 or older versions of egcs.  It is supported in GCC 2.95 and newer versions.

     If you do not pass this flag, all languages available in the gcc sub-tree will be configured.  Re-defining LANGUAGES when calling make bootstrap *does not* work anymore, as those language sub-directories might not have been configured!

  * --disable-libgcj -- Specify that the run-time libraries used by GCJ should not be built.  This is useful in case you intend to use GCJ with some other run-time, or you're going to install it separately, or it just happens not to build on your particular machine.  In general, if the Java front-end is enabled, the GCJ libraries will be enabled too, unless they're known to not work on the target platform.  If GCJ is enabled but libgcj isn't built, you may need to port it; in this case, before modifying the top-level configure.in so that libgcj is enabled by default on this platform, you may use --enable-libgcj to override the default.

  * --with-dwarf2 -- Specify that the compiler should use DWARF2 debugging information as the default.

Some options which only apply to building cross compilers:

  * --with-headers=DIR -- Specifies a directory which has target include files. This options is required when building a cross compiler, if PREFIX/TARGET/sys-include doesn't pre-exist. These include files will be copied into the gcc install directory. Fixincludes will be run on these files to make them compatible with gcc.

  * --with-libs=``dir1 dir2 ... dirN'' -- Specifies a list of directories which contain the target runtime libraries.  These libraries will be copied into the gcc install directory.

  * --with-newlib -- Specifies that ``newlib'' is being used as the target C library.  This causes __eprintf to be omitted from libgcc.a on the assumption that it will be provided by newlib.

Note that each --enable option has a corresponding --disable option and that each --with option has a corresponding --without option.

Building
********

Now that GCC is configured, you are ready to build the compiler and runtime libraries.

We highly recommend that GCC be built using GNU make; other versions may work, then again they might not.

(For example, many broken versions of make will fail if you use the recommended setup where OBJDIR is different from SRCDIR.)

Building a native compiler
==========================

For a native build issue the command make bootstrap.  This will build the entire GCC system, which includes the following steps:

  * Build host tools necessary to build the compiler such as texinfo, bison, gperf.

  * Build target tools for use by the compiler such as binutils (bfd, binutils, gas, gprof, ld, and opcodes)

     if they have been individually linked or moved into the top level GCC source tree before configuring.

  * Perform a 3-stage bootstrap of the compiler.

  * Perform a comparison test of the stage2 and stage3 compilers.

  * Build runtime libraries using the stage3 compiler from the previous step.

If you are short on disk space you might consider make bootstrap-lean instead.  This is identical to make bootstrap except that object files from the stage1 and stage2 of the 3-stage bootstrap of the compiler are deleted as soon as they are no longer needed.

If you want to save additional space during the bootstrap and in the final installation as well, you can build the compiler binaries without debugging information with make CFLAGS='-O' LIBCFLAGS='-g -O2' LIBCXXFLAGS='-g -O2 -fno-implicit-templates' bootstrap.  This will save roughly 40% of disk space both for the bootstrap and the final installation. (Libraries will still contain debugging information.)

If you used the flag --enable-languages=... to restrict the compilers to be built, only those you've actually enabled will be built. This will of course only build those runtime libraries, for which the particular compiler has been built.  Please note, that re-defining LANGUAGES when calling make bootstrap *does not* work anymore!

Building a cross compiler
=========================

We recommend reading the crossgcc FAQ for information about building cross compilers.

When building a cross compiler, it is not generally possible to do a 3-stage bootstrap of the compiler.  This makes for an interesting problem as parts of GCC can only be built with GCC.

To build a cross compiler, we first recommend building and installing a native compiler.  You can then use the native GCC compiler to build the cross compiler.

Assuming you have already installed a native copy of GCC and configured your cross compiler, issue the command make, which performs the following steps:

  * Build host tools necessary to build the compiler such as texinfo, bison, gperf.

  * Build target tools for use by the compiler such as binutils (bfd, binutils, gas, gprof, ld, and opcodes) if they have been individually linked or moved into the top level GCC source tree before configuring.

  * Build the compiler (single stage only).

  * Build runtime libraries using the compiler from the previous step.

Note that if an error occurs in any step the make process will exit.

Building in parallel
====================

If you have a multiprocessor system you can use make bootstrap MAKE="make -j 2" -j 2 or just make -j 2 bootstrap for GNU Make 3.79 and above instead of just make bootstrap when building GCC.  You can use a bigger number instead of two if you like.  In most cases, it won't help to use a number bigger than the number of processors in your machine.

Installing GCC: Testing
***********************

Please note that this is only applicable to current development versions of GCC and GCC 3.0 or later. GCC 2.95.x does not come with a testsuite.

Before you install GCC, you might wish to run the testsuite. This step is optional and may require you to download additional software.

First, you must have downloaded the testsuites. The full distribution contains testsuites; only if you downloaded the ``core'' compiler plus any front ends, you do not have the testsuites.

Second, you must have a current version of DejaGnu installed; dejagnu 1.3 is not sufficient.

Now you may need specific preparations:

  * In order to run the libio tests on targets which do not fully support Unix/POSIX commands (e.g. Cygwin), the references to the dbz directory have to be deleted from libio/configure.in.

  * The following environment variables must be set appropriately, as in the following example (which assumes that DejaGnu has been installed under /usr/local):

               TCL_LIBRARY = /usr/local/share/tcl8.0
               DEJAGNULIBS = /usr/local/share/dejagnu

     On systems such as Cygwin, these paths are required to be actual paths, not mounts or links; presumably this is due to some lack of portability in the DejaGnu code.

Finally, you can run the testsuite (which may take a long time):

          cd objdir; make -k check

The testing process will try to test as many components in the GCC distribution as possible, including the C, C++ and Fortran compilers as well as the C++ runtime libraries.

How can I run the test suite on selected tests?
===============================================

As a first possibility to cut down the number of tests that are run it is possible to use make check-gcc or make check-g++ in the gcc subdirectory of the object directory. To further cut down the tests the following is possible:

         make check-gcc RUNTESTFLAGS="execute.exp <other options>"

This will run all gcc execute tests in the testsuite.

         make check-g++ RUNTESTFLAGS="old-deja.exp=9805* <other options>"

This will run the g++ "old-deja" tests in the testsuite where the filename matches 9805*.

The *.exp files are located in the testsuite directories of the GCC source, the most important ones being compile.exp, execute.exp, dg.exp and old-deja.exp. To get a list of the possible *.exp files, pipe the output of make check into a file and look at the Running ...  .exp lines.

How to interpret test results
=============================

After the testsuite has run you'll find various *.sum and *.log files in the testsuite subdirectories. The *.log files contain a detailed log of the compiler invocations and the corresponding results, the *.sum files summarize the results. These summaries list all the tests that have been run with a corresponding status code:

  * PASS: the test passed as expected

  * XPASS: the test unexpectedly passed

  * FAIL: the test unexpectedly failed

  * XFAIL: the test failed as expected

  * UNSUPPORTED: the test is not supported on this platform

  * ERROR: the testsuite detected an error

  * WARNING: the testsuite detected a possible problem

It is normal for some tests to report unexpected failures.  At the current time our testing harness does not allow fine grained control over whether or not a test is expected to fail.  We expect to fix this problem in future releases.

Submitting test results
=======================

If you want to report the results to the GCC project, use the contrib/test_summary shell script. Start it in the objdir with

         srcdir/contrib/test_summary -p your_commentary.txt -m gcc-testresults@gcc.gnu.org |sh

This script uses the Mail program to send the results, so make sure it is in your PATH. The file your_commentary.txt is prepended to the testsuite summary and should contain any special remarks you have on your results or your build environment. Please do not edit the testsuite result block or the subject line, as these messages are automatically parsed and presented at the GCC testresults web page.  Here you can also gather information on how specific tests behave on different platforms and compare them with your results. A few failing testcases are possible even on released versions and you should look here first if you think your results are unreasonable.

Installing GCC: Final installation
**********************************

Now that GCC has been built and tested, you can install it with cd objdir; make install for a native compiler or cd objdir; make install LANGUAGES="c c++" for a cross compiler (note installing cross compilers will be easier in the next release!).

That step completes the installation of GCC; user level binaries can be found in PREFIX/bin where PREFIX is the value you specified with the --prefix to configure (or /usr/local by default).

If you don't mind, please quickly review the build status page. If your system is not listed, send a note to gcc@gcc.gnu.org indicating that you successfully built and installed GCC.

Include the output from running SRCDIR/config.guess.  (Do not send us the config.guess file itself, just the output from running it!)

If you find a bug, please report it following our bug reporting guidelines.

Installing GCC: Binaries
************************

We are often asked about pre-compiled versions of GCC. While we cannot provide these for all platforms, below you'll find links to binaries for various platforms where creating them by yourself is not easy due to various reasons.

Please note that we did not create these binaries, nor do we support them.  If you have any problems installing them, please contact their makers.

  * AIX:

       * Bull's Freeware and Shareware Archive for AIX;

       * UCLA Software Library for AIX;

  * DOS - DJGPP;

  * HP-UX Porting Center;

  * SCO OpenServer/Unixware;

  * Solaris (SPARC, Intel) - Sunfreeware;

  * SGI - SGI Freeware;

  * Windows 95, 98, and NT:

       * The Cygwin project;

       * GNU Win32 related projects by Mumit Khan.

  * The Written Word offers binaries for Solaris 2.5.1, 2.6, 2.7/SPARC, 2.7/Intel, IRIX 6.2, 6.5, Digital UNIX 4.0D, HP-UX 10.20, and HP-UX 11.00.

  * Hitachi H8/300[HS] - GNU Development Tools for the Hitachi H8/300[HS] Series

In addition to those specific offerings, you can get a binary distribution CD-ROM from the Free Software Foundation. It contains binaries for a number of platforms, and includes not only GCC, but other stuff as well. The current CD does not contain the latest version of GCC, but it should allow bootstrapping the compiler. An updated version of that disk is in the works.

Host/target specific installation notes for GCC
***********************************************

Please read this document carefully before installing the GNU Compiler Collection on your machine.

  * alpha*-dec-linux*

  * alpha*-dec-osf*

  * arm*-*-linux-gnu

  * avr

  * DOS

  * h8300-hms

  * hppa*-hp-hpux*

  * hppa*-hp-hpux9

  * hppa*-hp-hpux10

  * hppa*-hp-hpux11

  * *-*-linux-gnu

  * i?86-*-linux*

  * i?86-*-sco3.2v5*

  * i?86-*-solaris*

  * i?86-*-udk

  * *-ibm-aix*

  * m68k-*-nextstep*

  * m68k-sun-sunos4.1.1

  * mips*-sgi-irix[45]

  * mips*-sgi-irix6

  * powerpc-*-linux-gnu*

  * *-*-solaris*

  * sparc-sun-solaris*

  * sparc-sun-solaris2.7

  * *-sun-solaris2.8

  * Sun V5.0 Compiler Bugs

  * sparc-sun-sunos*

  * sparc-unknown-linux-gnulibc1

  * sparc64-*-*

  * Microsoft Windows

  * OS/2

  * Older systems

  * all ELF targets (SVR4, Solaris, etc.)

We require binutils 2.11 or newer.  Previous binutils releases had a number of problems with DWARF2 debugging information, not the least of which is incorrect linking of shared libraries.

If you install a shared libstdc++ and, when you link a non-trivial C++ program (for example, gcc/testsuite/g++.other/delete3.C), the linker reports a couple of errors about multiply-defined symbols (for example, nothrow, __throw and terminate(void)), you've probably got a linker bug, for which there's no known fix.  The officially recommended work-around is to remove the shared libstdc++.

An alternative solution is to arrange that all symbols from libgcc get copied to the shared libstdc++; see detailed solution below.  (Surprising as it may seem, this does indeed fix the problem!)  Beware that this may bring you binary-compatibility problems in the future, if you don't use the same work-around next time you build libstdc++: if programs start to depend on libstdc++ to provide symbols that used to be only in libgcc, you must arrange that libstdc++ keeps providing them, otherwise the programs will have to be relinked.

The magic spell is to add -Wl,-all,-lgcc,-none to the definition of macro SHDEPS in libstdc++/config/dec-osf.ml before alpha*-dec-osf*/libstdc++/Makefile is created (a patch that does just that is available).  If the Makefile already exists, run ./config.status within directory alpha*-dec-osf*/libstdc++ (and alpha*-dec-osf*/ieee/libstdc++, if it also exists). Remove any existing libstdc++.so* from such directories, and run make all-target-libstdc++ in the top-level directory, then make install-target-libstdc++.

If you have already removed the build tree, you may just remove libstdc++.so.2.10.0 from the install tree and re-create it with the command gcc -shared -o libstdc++.so.2.10.0 -Wl,-all,-lstdc++,-lgcc,-none -lm. If the ieee sub-directory exists, repeat this command in it, with the additional flag -mieee.

We require GNU binutils 2.10 or newer.

Use configure --target=avr --enable-languages="c"' to configure GCC.

Further installation notes and other useful information about AVR tools can also be obtained from:

  * http://home.overta.ru/users/denisc

  * http://www.itnet.pl/amelektr/avr

We strongly recommend using binutils 2.11 or newer.

The following error:

       Error: register required

indicates that you should upgrade to a newer version of the binutils.

Please have a look at our binaries page.

Please have a look at our binaries page.

We highly recommend using gas/binutils-2.8 or newer on all hppa platforms; you may encounter a variety of problems when using the HP assembler.

Specifically, -g does not work on HP-UX (since that system uses a peculiar debugging format which GCC does not know about), unless you use GAS and GDB and configure GCC with the --with-gnu-as and --with-as=... options.

If you wish to use pa-risc 2.0 architecture support, you must use either the HP assembler, gas/binutils-2.11 or a recent snapshot of gas.

More specific information to hppa*-hp-hpux* targets follows.

The HP assembler has major problems on this platform.  We've tried to work around the worst of the problems.  However, those workarounds may be causing linker crashes in some circumstances; the workarounds also probably prevent shared libraries from working.  Use the GNU assembler to avoid these problems.

The configuration scripts for GCC will also trigger a bug in the hpux9 shell.  To avoid this problem set CONFIG_SHELL to /bin/ksh and SHELL to /bin/ksh in your environment.

For hpux10.20, we highly recommend you pick up the latest sed patch PHCO_19798 from HP.  HP has two sites which provide patches free of charge:

  * http://us-support.external.hp.comUS, Canada, Asia-Pacific, and Latin-America

  * Europe

The HP assembler on these systems is much better than the hpux9 assembler, but still has some problems.  Most notably the assembler inserts timestamps into each object file it creates, causing the 3-stage comparison test to fail during a make bootstrap.  You should be able to continue by saying make all after getting the failure from make bootstrap.

GCC 2.95.2 does not support HP-UX 11, and it cannot generate 64-bit object files. Current (as of late 2000) snapshots and GCC 3.0 do support HP-UX 11.

If you use glibc 2.2 (or 2.1.9x), GCC 2.95.2 won't install out-of-the-box.  You'll get compile errors while building libstdc++. The patch glibc-2.2.patch, that is to be applied in the GCC source tree, fixes the compatibility problems.

You will need binutils-2.9.1.0.15 or newer for exception handling to work.

If you receive Signal 11 errors when building on GNU/Linux, then it is possible you have a hardware problem.  Further information on this can be found on www.bitwizard.nl.

Unlike earlier versions of GCC, the ability to generate COFF with this target is no longer provided.

Earlier versions of GCC emitted Dwarf-1 when generating ELF to allow the system debugger to be used.  That support was too burdensome to maintain.  GCC now emits only dwarf-2 for this target.  This means you may use either the UDK debugger or GDB to debug programs built by this version of GCC.

If you are building languages other than C, you must follow the instructions about invoking make bootstrap because the native OpenServer compiler will build a cc1plus that will not correctly parse many valid C++ programs including those in libgcc.a. You must do a make bootstrap if you are building with the native compiler.

Use of the -march-pentiumpro flag can result in unrecognized opcodes when using the native assembler on OS versions before 5.0.6. (Support for P6 opcodes was added to the native ELF assembler in that version.)  While it's rather rare to see these emitted by GCC yet, errors of the basic form:

       /usr/tmp/ccaNlqBc.s:22:unknown instruction: fcomip
       /usr/tmp/ccaNlqBc.s:50:unknown instruction: fucomip

are symptoms of this problem.  You may work around this by not building affected files with that flag, by using the GNU assembler, or by using the assembler provided with the current version of the OS. Users of GNU assembler should see the note below for hazards on doing so.

The native SCO assembler that is provided with the OS at no charge is normally required.  If, however, you must be able to use the GNU assembler (perhaps you're compiling code with asms that require GAS syntax) you may configure this package using the flags --with-gnu-as.  You must use a recent version of GNU binutils; versions past 2.9.1 seem to work well.

In general, the --with-gnu-as option isn't as well tested as the native assembler.

Look in gcc/config/i386/sco5.h (search for "messy") for additional OpenServer-specific flags.

Systems based on OpenServer before 5.0.4 (uname -X will tell you what you're running) require TLS597 from ftp.sco.com/TLS for C++ constructors and destructors to work right.

The system linker in (at least) 5.0.4 and 5.0.5 will sometimes do the wrong thing for a construct that GCC will emit for PIC code.  This can be seen as execution testsuite failures when using -fPIC on 921215-1.c, 931002-1.c, nestfunc-1.c, and gcov-1.c. For 5.0.5, an updated linker that will cure this problem is available.  You must install both ftp://ftp.sco.com/Supplements/rs505a/ and OSS499A.

The dynamic linker in OpenServer 5.0.5 (earlier versions may show the same problem) aborts on certain g77-compiled programs.  It's particularly likely to be triggered by building Fortran code with the -fPIC flag. Although it's conceivable that the error could be triggered by other code, only G77-compiled code has been observed to cause this abort. If you are getting core dumps immediately upon execution of your g77 program - and especially if it's compiled with -fPIC - try applying sco_osr5_g77.patch to your libf2c and rebuilding GCC. Affected faults, when analyzed in a debugger, will show a stack backtrace with a fault occurring in rtld() and the program running as /usr/lib/ld.so.1.  This problem has been reported to SCO engineering and will hopefully be addressed in later releases.

GCC 2.95.2, when configured to use the GNU assembler, would invoke it with the -s switch, that GNU as up to 2.9.5.0.12 does not support.  If you'd rather not use a newer GNU as nor the native assembler, you'll need the patch x86-sol2-gas.patch.

This target emulates the SCO Universal Development Kit and requires that package be installed.  (If it is installed, you will have a /udk/usr/ccs/bin/cc  file present.)  It's very much like the i?86-*-unixware7* target but is meant to be used when hosting on a system where UDK isn't the default compiler such as OpenServer 5 or Unixware 2.  This target will generate binaries that will run on OpenServer, Unixware 2, or Unixware 7, with the same warnings and caveats as the SCO UDK.

You can stage1 with either your native compiler or with UDK.   If you don't do a full bootstrap when initially building with your native compiler you will have an utterly unusable pile of bits as your reward.

This target is a little tricky to build because we have to distinguish it from the native tools (so it gets headers, startups, and libraries from the right place) while making the tools not think we're actually building a cross compiler.   The easiest way to do this is with a configure command like this:

CC=/udk/usr/ccs/bin/cc <i>/your/path/to/</i>gcc/configure --host=i686-pc-udk --target=i686-pc-udk --program-prefix=udk-

You should substitute 'i686' in the above command with the appropriate processor for your host.

You should follow this with a make bootstrap  then make install.  You can then access the UDK-targeted GCC tools by adding udk- before the commonly known name.  For example, to invoke the C compiler, you would use udk-gcc. They will coexist peacefully with any native-target GCC tools you may have installed.

AIX Make frequently has problems with GCC makefiles.  GNU Make 3.76 or newer is recommended to build on this platform.

Errors involving "alloca" when building GCC generally are due to an incorrect definition of CC in the Makefile or mixing files compiled with the native C compiler and GCC.  During the stage1 phase of the build, the native AIX compiler must be invoked as "cc" (not "xlc").  Once configure has been informed of "xlc", one needs to use make distclean to remove the configure cache files and ensure that CC environment variable does not provide a definition that will confuse configure. If this error occurs during stage2 or later, then the problem most likely is the version of Make (see above).

Binutils 2.10 does not support AIX 4.3.  Binutils available from the AIX Toolbox for Linux: GNU and Open Source tools for AIX; website does work.  Binutils 2.11 is expected to include AIX 4.3 support.  The GNU Assembler is necessary for libstdc++ to build.  The AIX native ld still is recommended.  The native AIX tools do interoperate with GCC.

Linking executables and shared libraries may produce warnings of duplicate symbols.  The assembly files generated by GCC for AIX always have included multiple symbol definitions for certain global variable and function declarations in the original program.  The warnings should not prevent the linker from producing a correct library or runnable executable.

AIX 4.3 utilizes a "large format" archive to support both 32-bit and 64-bit object modules.  The routines provided in AIX 4.3.0 and AIX 4.3.1 to parse archive libraries did not handle the new format correctly. These routines are used by GCC and result in error messages during linking such as "not a COFF file".  The version of the routines shipped with AIX 4.3.1 should work for a 32-bit environment.  The -g option of the archive command may be used to create archives of 32-bit objects using the original "small format".  A correct version of the routines is shipped with AIX 4.3.2.

Some versions of the AIX binder (linker) can fail with a relocation overflow severe error when the -bbigtoc option is used to link GCC-produced object files into an executable that overflows the TOC.  A fix for APAR IX75823 (OVERFLOW DURING LINK WHEN USING GCC AND -BBIGTOC) is available from IBM Customer Support and from its service.boulder.ibm.com website as PTF U455193.

The AIX 4.3.2.1 linker (bos.rte.bind_cmds Level 4.3.2.1) will dump core with a segmentation fault when invoked by any version of GCC.  A fix for APAR IX87327 is available from IBM Customer Support and from its service.boulder.ibm.com website as PTF U461879.  This fix is incorporated in AIX 4.3.3 and above.

The initial assembler shipped with AIX 4.3.0 generates incorrect object files.  A fix for APAR IX74254 (64BIT DISASSEMBLED OUTPUT FROM COMPILER FAILS TO ASSEMBLE/BIND) is available from IBM Customer Support and from its service.boulder.ibm.com website as PTF U453956.  This fix is incorporated in AIX 4.3.1 and above.

AIX provides National Language Support (NLS).  Compilers and assemblers use NLS to support locale-specific representations of various data formats including floating-point numbers (e.g., "."  vs "," for separating decimal fractions).  There have been problems reported where GCC does not produce the same floating-point formats that the assembler expects.  If one encouters this problem, set the LANG environment variable to "C" or "En_US".

You absolutely must use GNU sed and GNU make on this platform.

On NEXTSTEP 3.x where x < 3 the build of GCC will abort during stage1 with an error message like this:

       _eh
       /usr/tmp/ccbbsZ0U.s:987:Unknown pseudo-op: .section
       /usr/tmp/ccbbsZ0U.s:987:Rest of line ignored. 1st junk character
       valued 95 (_).

The reason for this is the fact that NeXT's assembler for these versions of the operating system does not support the .section pseudo op that's needed for full C++ exception functionality.

As NeXT's assembler is a derived work from GNU as, a free replacement that does can be obtained at ftp://ftp.next.peak.org:/next-ftp/next/apps/devtools/as.3.3.NIHS.s.tar.gz.

If you try to build the integrated C++ & C++ runtime libraries on this system you will run into trouble with include files.  The way to get around this is to use the following sequence.  Note you must have write permission to the directory PREFIX you specified in the configuration process of GCC for this sequence to work.

       cd bld-gcc
       make all-texinfo all-bison all-byacc all-binutils all-gas all-ld
       cd gcc
       make bootstrap
       make install-headers-tar
       cd ..
       make bootstrap3

It is reported that you may need the GNU assembler on this platform.

You must use GAS on these platforms, as the native assembler can not handle the code for exception handling support. Either of these messages indicates that you are using the MIPS assembler when instead you should be using GAS:

  as0: Error: ./libgcc2.c, line 1:Badly delimited numeric literal .4byte $LECIE1-$LSCIE1 as0: Error: ./libgcc2.c, line 1:malformed statement

or:

  as0: Error: /src/bld-gcc/gcc/libgcc2.c, line 1:undefined symbol in expression .word $LECIE1-$LSCIE1

These systems don't have ranlib, which various components in GCC need; you should be able to avoid this problem by installing GNU binutils, which includes a functional ranlib for this system.

You may get the following warning on irix4 platforms, it can be safely ignored.

       warning: foo.o does not have gp tables for all its sections.

When building GCC, the build process loops rebuilding cc1 over and over again.  This happens on mips-sgi-irix5.2, and possibly other platforms.

It has been reported that this is a known bug in the make shipped with IRIX 5.2.  We recommend you use GNU make instead of the vendor supplied make program; however, you may have success with "smake" on IRIX 5.2 if you do not have GNU make available.

See http://freeware.sgi.com/ for more information about using GCC on IRIX platforms.

You must not use GAS on irix6 platforms; doing so will only cause problems.

These systems don't have ranlib, which various components in GCC need; you should be able to avoid this problem by making a dummy script called ranlib which just exits with zero status and placing it in your path.

If you are using Irix cc as your bootstrap compiler, you must ensure that the N32 ABI is in use.  To test this, compile a simple C file with cc and then run file on the resulting object file.  The output should look like:

         test.o: ELF N32 MSB ...

If you see:

         test.o: ELF 32-bit MSB

then your version of cc uses the O32 ABI default.  You should set the environment variable CC to cc -n32 before configuring GCC.

GCC does not currently support generating O32 ABI binaries in the mips-sgi-irix6 configurations.  It used to be possible to create a GCC with O32 ABI only support by configuring it for the mips-sgi-irix5 target.  See the link below for details.

GCC does not correctly pass/return structures which are smaller than 16 bytes and which are not 8 bytes. The problem is very involved and difficult to fix. It affects a number of other targets also, but IRIX 6 is affected the most, because it is a 64 bit target, and 4 byte structures are common. The exact problem is that structures are being padded at the wrong end, e.g. a 4 byte structure is loaded into the lower 4 bytes of the register when it should be loaded into the upper 4 bytes of the register.

GCC is consistent with itself, but not consistent with the SGI C compiler (and the SGI supplied runtime libraries), so the only failures that can happen are when there are library functions that take/return such structures. There are very few such library functions. I can only recall seeing two of them: inet_ntoa, and semctl.

See http://freeware.sgi.com/ for more information about using GCC on IRIX platforms.

You will need binutils-2.9.4.0.8 or newer for a working GCC. It is strongly recommended to recompile binutils if you initially built it with gcc-2.7.2.x.

Starting with Solaris, Sun does not ship a C compiler any more. To bootstrap and install GCC you first have to install a pre-built compiler, see our binaries page for details.

You must use GNU Make to build GCC on Solaris 2.  If you don't have GNU Make installed, you can use the prebuilt compiler mentioned above to build it.

Sun as 4.X is broken in that it cannot cope with long symbol names. A typical error message might look similar to the following:

/usr/ccs/bin/as: "/var/tmp/ccMsw135.s", line 11041: error: can't compute value of an expression involving an external symbol.

This is Sun bug 4237974.  This is fixed with patch 108908-02 and has been fixed in later (5.x) versions of the assembler.

binutils 2.9.1 has known bugs on this platform. We recommend to use binutils 2.10 or the vendor tools (Sun as, Sun ld).

Unfortunately, C++ shared libraries, including libstdc++, won't work properly if assembled with Sun as: the linker will complain about relocations in read-only sections, in the definition of virtual tables. Also, Sun as fails to process long symbols resulting from mangling template-heavy C++ function names.

Sun patch 107058-01 (1999-01-13) for SPARC Solaris 7 triggers a bug in the dynamic linker.  This problem (Sun bug 4210064) affects GCC 2.8 and later, including all EGCS releases.  Sun formerly recommended 107058-01 for all Solaris 7 users, but around 1999-09-01 it started to recommend it only for people who use Sun's compilers.

Here are some workarounds to this problem:

  * Do not install Sun patch 107058-01 until after Sun releases a complete patch for bug 4210064.  This is the simplest course to take, unless you must also use Sun's C compiler.  Unfortunately 107058-01 is preinstalled on some new Solaris-based hosts, so you may have to back it out.

  * Copy the original, unpatched Solaris 7 /usr/ccs/bin/as into /usr/local/lib/gcc-lib/sparc-sun-solaris2.7/2.95.1/as, adjusting the latter name to fit your local conventions and software version numbers.

  * Install Sun patch 106950-03 (1999-05-25) or later.  Nobody with both 107058-01 and 106950-03 installed has reported the bug with GCC and Sun's dynamic linker.  This last course of action is riskiest, for two reasons.  First, you must install 106950 on all hosts that run code generated by GCC; it doesn't suffice to install it only on the hosts that run GCC itself.  Second, Sun says that 106950-03 is only a partial fix for bug 4210064, but Sun doesn't know whether the partial fix is adequate for GCC.  Revision -08 or later should fix the bug, but (as of 1999-10-06) it is still being tested.

Sun bug 4296832 turns up when compiling X11 headers with GCC 2.95 or newer:  g++ will complain that types are missing.  These headers assume that omitting the type means 'int'; this assumption worked for C89 but is wrong for C++, and is now wrong for C99 also.

g++ accepts such (illegal) constructs with the option -fpermissive; it will assume that any missing type is 'int' (as defined by C89).

For Solaris 8, this is fixed by revision 24 or later of patch 108652 (for SPARCs) or 108653 (for Intels).

The Sun V5.0 compilers are known to mis-compile GCC 2.95 and GCC 2.95.1, which in turn causes GCC to fail its bootstrap comparison test. GCC 2.95.2 has a workaround.

A bug in the SunOS4 linker will cause it to crash when linking -fPIC compiled objects (and will therefore not allow you to build shared libraries).

To fix this problem you can either use the most recent version of binutils or get the latest SunOS4 linker patch (patch ID 100170-10) from Sun's patch site.

It has been reported that you might need binutils-2.8.1.0.23 for this platform, too.

GCC version 2.95 is not able to compile code correctly for sparc64 targets.  Users of the Linux kernel, at least, 12~can use the sparc32 program to start up a new shell invocation with an environment that causes configure to recognize (via uname -a) the system as SPARC-*-* instead.

A port of GCC 2.95.x is included with the Cygwin environment.

Current (as of early 2001) snapshots of GCC will build under Cygwin without modification.

GCC does not currently support OS/2.  However, Andrew Zabolotny has been working on a generic OS/2 port with pgcc.  The current code code can be found at http://www.goof.com/pcg/os2/.

An older copy of GCC 2.8.1 is included with the EMX tools available at ftp://ftp.leo.org/pub/comp/os/os2/leo/devtools/emx+gcc/.

GCC contains support files for many older (1980s and early 1990s) Unix variants.  For the most part, support for these systems has not been deliberately removed, but it has not been maintained for several years and may suffer from bitrot.  Support from some systems has been removed from GCC 3: fx80, ns32-ns-genix, pyramid, tahoe, gmicro, spur; most of these targets had not been updated since GCC version 1.

Support for older systems as targets for cross-compilation is less problematic than support for them as hosts for GCC; if an enthusiast wishes to make such a target work again (including resurrecting any of the targets that never worked with GCC 2, starting from the last CVS version before they were removed), patches following the usual requirements would be likely to be accepted, since they should not affect the support for more modern targets.

Support for old systems as hosts for GCC can cause problems if the workarounds for compiler, library and operating system bugs affect the cleanliness or maintainability of the rest of GCC.  In some cases, to bring GCC up on such a system, if still possible with current GCC, may require first installing an old version of GCC which did work on that system, and using it to compile a more recent GCC, to avoid bugs in the vendor compiler.  Old releases of GCC 1 and GCC 2 are available in the old-releases directory on the GCC mirror sites.  Header bugs may generally be avoided using fixincludes, but bugs or deficiencies in libraries and the operating system may still cause problems.

For some systems, old versions of GNU binutils may also be useful, and are available from pub/binutils/old-releases on sources.redhat.com mirror sites.

Some of the information on specific systems above relates to such older systems, but much of the information about GCC on such systems (which may no longer be applicable to current GCC) is to be found in the GCC texinfo manual.

C++ support is significantly better on ELF targets if you use the GNU linker; duplicate copies of inlines, vtables and template instantiations will be discarded automatically.