This is ../../gcc-3.4/gcc/doc/gccinstall.info, produced by makeinfo
version 4.2 from ../../gcc-3.4/gcc/doc/install.texi.


File: gccinstall.info,  Node: Building,  Next: Testing,  Prev: Configuration,  Up: Installing GCC

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.  GNU make is required for
compiling GNAT (the Ada compiler) and the Java runtime library.

   (For example, many broken versions of make will fail if you use the
recommended setup where OBJDIR is different from SRCDIR.  Other broken
versions may recompile parts of the compiler when installing the
compiler.)

   Some commands executed when making the compiler may fail (return a
nonzero status) and be ignored by `make'.  These failures, which are
often due to files that were not found, are expected, and can safely be
ignored.

   It is normal to have compiler warnings when compiling certain files.
Unless you are a GCC developer, you can generally ignore these warnings
unless they cause compilation to fail.  Developers should attempt to fix
any warnings encountered, however they can temporarily continue past
warnings-as-errors by specifying the configure flag `--disable-werror'.

   On certain old systems, defining certain environment variables such
as `CC' can interfere with the functioning of `make'.

   If you encounter seemingly strange errors when trying to build the
compiler in a directory other than the source directory, it could be
because you have previously configured the compiler in the source
directory.  Make sure you have done all the necessary preparations.

   If you build GCC on a BSD system using a directory stored in an old
System V file system, problems may occur in running `fixincludes' if the
System V file system doesn't support symbolic links.  These problems
result in a failure to fix the declaration of `size_t' in
`sys/types.h'.  If you find that `size_t' is a signed type and that
type mismatches occur, this could be the cause.

   The solution is not to use such a directory for building GCC.

   When building from CVS or snapshots, or if you modify parser sources,
you need the Bison parser generator installed.  Any version 1.25 or
later should work; older versions may also work.  If you do not modify
parser sources, releases contain the Bison-generated files and you do
not need Bison installed to build them.

   When building from CVS or snapshots, or if you modify Texinfo
documentation, you need version 4.2 or later of Texinfo installed if you
want Info documentation to be regenerated.  Releases contain Info
documentation pre-built for the unmodified documentation in the release.

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 as in the following example.  This will save
roughly 40% of disk space both for the bootstrap and the final
installation.  (Libraries will still contain debugging information.)

          make CFLAGS='-O' LIBCFLAGS='-g -O2' \
            LIBCXXFLAGS='-g -O2 -fno-implicit-templates' bootstrap

   If you wish to use non-default GCC flags when compiling the stage2
and stage3 compilers, set `BOOT_CFLAGS' on the command line when doing
`make bootstrap'.  Non-default optimization flags are less well tested
here than the default of `-g -O2', but should still work.  In a few
cases, you may find that you need to specify special flags such as
`-msoft-float' here to complete the bootstrap; or, if the native
compiler miscompiles the stage1 compiler, you may need to work around
this, by choosing `BOOT_CFLAGS' to avoid the parts of the stage1
compiler that were miscompiled, or by using `make bootstrap4' to
increase the number of stages of bootstrap.

   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!

   If the comparison of stage2 and stage3 fails, this normally indicates
that the stage2 compiler has compiled GCC incorrectly, and is therefore
a potentially serious bug which you should investigate and report.  (On
a few systems, meaningful comparison of object files is impossible; they
always appear "different".  If you encounter this problem, you will
need to disable comparison in the `Makefile'.)

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.  The installed native compiler needs to be
GCC version 2.95 or later.

   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
====================

   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 `make bootstrap'
to build GCC in parallel.  You can also specify a bigger number, and in
most cases using a value greater than the number of processors in your
machine will result in fewer and shorter I/O latency hits, thus
improving overall throughput; this is especially true for slow drives
and network filesystems.

Building the Ada compiler
=========================

   In order to build GNAT, the Ada compiler, you need a working GNAT
compiler (GNAT version 3.14 or later, or GCC version 3.1 or later),
since the Ada front end is written in Ada (with some GNAT-specific
extensions), and GNU make.

   However, you do not need a full installation of GNAT, just the GNAT
binary `gnat1', a copy of `gnatbind', and a compiler driver which can
deal with Ada input (by invoking the `gnat1' binary).  You can specify
this compiler driver by setting the `ADAC' environment variable at the
configure step.  `configure' can detect the driver automatically if it
has got a common name such as `gcc' or `gnatgcc'.  Of course, you still
need a working C compiler (the compiler driver can be different or not).
`configure' does not test whether the GNAT installation works and has a
sufficiently recent version; if too old a GNAT version is installed,
the build will fail unless `--enable-languages' is used to disable
building the Ada front end.

   Additional build tools (such as `gnatmake') or a working GNAT
run-time library installation are usually _not_ required.  However, if
you want to bootstrap the compiler using a minimal version of GNAT, you
have to issue the following commands before invoking `make bootstrap'
(this assumes that you start with an unmodified and consistent source
distribution):

         cd SRCDIR/gcc/ada
         touch treeprs.ads [es]info.h nmake.ad[bs]

   At the moment, the GNAT library and several tools for GNAT are not
built by `make bootstrap'.  You have to invoke `make gnatlib_and_tools'
in the `OBJDIR/gcc' subdirectory before proceeding with the next steps.

   For example, you can build a native Ada compiler by issuing the
following commands (assuming `make' is GNU make):

         cd OBJDIR
         SRCDIR/configure --enable-languages=c,ada
         cd SRCDIR/gcc/ada
         touch treeprs.ads [es]info.h nmake.ad[bs]
         cd OBJDIR
         make bootstrap
         cd gcc
         make gnatlib_and_tools
         cd ..

   Currently, when compiling the Ada front end, you cannot use the
parallel build feature described in the previous section.

Building with profile feedback
==============================

   It is possible to use profile feedback to optimize the compiler
itself.  This should result in a faster compiler binary.  Experiments
done on x86 using gcc 3.3 showed approximately 7 percent speedup on
compiling C programs.  To bootstrap compiler with profile feedback, use
`make profiledbootstrap'.

   When `make profiledbootstrap' is run, it will first build a `stage1'
compiler.  This compiler is used to build a `stageprofile' compiler
instrumented to collect execution counts of instruction and branch
probabilities.  Then runtime libraries are compiled with profile
collected.  Finally a `stagefeedback' compiler is built using the
information collected.

   Unlike `make bootstrap' several additional restrictions apply.  The
compiler used to build `stage1' needs to support a 64-bit integral type.
It is recommended to only use GCC for this.  Also parallel make is
currently not supported since collisions in profile collecting may
occur.


File: gccinstall.info,  Node: Testing,  Next: Final install,  Prev: Building,  Up: Installing GCC

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

   Before you install GCC, we encourage you to run the testsuites and to
compare your results with results from a similar configuration that have
been submitted to the gcc-testresults mailing list.  Some of these
archived results are linked from the build status lists at
`http://gcc.gnu.org/buildstat.html', although not everyone who reports
a successful build runs the testsuites and submits the results.  This
step is optional and may require you to download additional software,
but it can give you confidence in your new GCC installation or point out
problems before you install and start using your new GCC.

   First, you must have downloaded the testsuites.  These are part of
the full distribution, but if you downloaded the "core" compiler plus
any front ends, you must download the testsuites separately.

   Second, you must have the testing tools installed.  This includes
DejaGnu 1.4.1 or 1.4.3 and later, Tcl, and Expect; the DejaGnu site has
links to these.

   If the directories where `runtest' and `expect' were installed are
not in the `PATH', you may need to set the following environment
variables 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

   This will test various components of GCC, such as compiler front
ends and runtime libraries.  While running the testsuite, DejaGnu might
emit some harmless messages resembling `WARNING: Couldn't find the
global config file.' or `WARNING: Couldn't find tool init file' that
can be ignored.

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

   In order to run sets of tests selectively, there are targets `make
check-gcc' and `make check-g++' in the `gcc' subdirectory of the object
directory.  You can also just run `make check' in a subdirectory of the
object directory.

   A more selective way to just run all `gcc' execute tests in the
testsuite is to use

         make check-gcc RUNTESTFLAGS="execute.exp OTHER-OPTIONS"

   Likewise, in order to run only the `g++' "old-deja" tests in the
testsuite with filenames matching `9805*', you would use

         make check-g++ RUNTESTFLAGS="old-deja.exp=9805* OTHER-OPTIONS"

   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.

   The Java runtime tests can be executed via `make check' in the
`TARGET/libjava/testsuite' directory in the build tree.

Additional testing for Java Class Libraries
===========================================

   The Mauve Project provides a suite of tests for the Java Class
Libraries.  This suite can be run as part of libgcj testing by placing
the Mauve tree within the libjava testsuite at
`libjava/testsuite/libjava.mauve/mauve', or by specifying the location
of that tree when invoking `make', as in `make MAUVEDIR=~/mauve check'.

   Jacks is a free test suite that tests Java compiler front ends.
This suite can be run as part of libgcj testing by placing the Jacks
tree within the libjava testsuite at
`libjava/testsuite/libjava.jacks/jacks'.

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

   The result of running the testsuite are 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 contain
status codes for all tests:

   * 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 may be
automatically processed.


File: gccinstall.info,  Node: Final install,  Prev: Testing,  Up: Installing GCC

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

   Now that GCC has been built (and optionally tested), you can install
it with
     cd OBJDIR; make install

   We strongly recommend to install into a target directory where there
is no previous version of GCC present.

   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
specified `--bindir', that directory will be used instead; otherwise,
if you specified `--exec-prefix', `EXEC-PREFIX/bin' will be used.)
Headers for the C++ and Java libraries are installed in
`PREFIX/include'; libraries in `LIBDIR' (normally `PREFIX/lib');
internal parts of the compiler in `LIBDIR/gcc' and `LIBEXECDIR/gcc';
documentation in info format in `INFODIR' (normally `PREFIX/info').

   When installing cross-compilers, GCC's executables are not only
installed into `BINDIR', that is, `EXEC-PREFIX/bin', but additionally
into `EXEC-PREFIX/TARGET-ALIAS/bin', if that directory exists.
Typically, such "tooldirs" hold target-specific binutils, including
assembler and linker.

   Installation into a temporary staging area or into a `chroot' jail
can be achieved with the command

     make DESTDIR=PATH-TO-ROOTDIR install

where PATH-TO-ROOTDIR is the absolute path of a directory relative to
which all installation paths will be interpreted.  Note that the
directory specified by `DESTDIR' need not exist yet; it will be created
if necessary.

   There is a subtle point with tooldirs and `DESTDIR': If you relocate
a cross-compiler installation with e.g. `DESTDIR=ROOTDIR', then the
directory `ROOTDIR/EXEC-PREFIX/TARGET-ALIAS/bin' will be filled with
duplicated GCC executables only if it already exists, it will not be
created otherwise.  This is regarded as a feature, not as a bug,
because it gives slightly more control to the packagers using the
`DESTDIR' feature.

   If you built a released version of GCC using `make bootstrap' then
please quickly review the build status page for your release, available
from `http://gcc.gnu.org/buildstat.html'.  If your system is not listed
for the version of GCC that you built, send a note to <gcc@gcc.gnu.org>
indicating that you successfully built and installed GCC.  Include the
following information:

   * Output from running `SRCDIR/config.guess'.  Do not send us that
     file itself, just the one-line output from running it.

   * The output of `gcc -v' for your newly installed gcc.  This tells
     us which version of GCC you built and the options you passed to
     configure.

   * Whether you enabled all languages or a subset of them.  If you
     used a full distribution then this information is part of the
     configure options in the output of `gcc -v', but if you downloaded
     the "core" compiler plus additional front ends then it isn't
     apparent which ones you built unless you tell us about it.

   * If the build was for GNU/Linux, also include:
        * The distribution name and version (e.g., Red Hat 7.1 or
          Debian 2.2.3); this information should be available from
          `/etc/issue'.

        * The version of the Linux kernel, available from `uname
          --version' or `uname -a'.

        * The version of glibc you used; for RPM-based systems like Red
          Hat, Mandrake, and SuSE type `rpm -q glibc' to get the glibc
          version, and on systems like Debian and Progeny use `dpkg -l
          libc6'.
     For other systems, you can include similar information if you
     think it is relevant.

   * Any other information that you think would be useful to people
     building GCC on the same configuration.  The new entry in the
     build status list will include a link to the archived copy of your
     message.

   We'd also like to know if the *Note host/target specific
installation notes: Specific didn't include your host/target
information or if that information is incomplete or out of date.  Send
a note to <gcc@gcc.gnu.org> telling us how the information should be
changed.

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

   If you want to print the GCC manuals, do `cd OBJDIR; make dvi'.  You
will need to have `texi2dvi' (version at least 4.2) and TeX installed.
This creates a number of `.dvi' files in subdirectories of `OBJDIR';
these may be converted for printing with programs such as `dvips'.  You
can also buy printed manuals from the Free Software Foundation, though
such manuals may not be for the most recent version of GCC.


File: gccinstall.info,  Node: Binaries,  Next: Specific,  Prev: Installing GCC,  Up: Top

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.

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

   * HP-UX:
        * HP-UX Porting Center;

        * Binaries for HP-UX 11.00 at Aachen University of Technology.

   * Motorola 68HC11/68HC12--GNU Development Tools for the Motorola
     68HC11/68HC12.

   * SCO OpenServer/Unixware.

   * Sinix/Reliant Unix--Siemens.

   * Solaris 2 (SPARC, Intel)--Sunfreeware.

   * SGI--SGI Freeware.

   * Microsoft Windows:
        * The Cygwin project;

        * The MinGW project.

   * The Written Word offers binaries for AIX 4.3.2.  IRIX 6.5, Digital
     UNIX 4.0D and 5.1, GNU/Linux (i386), HP-UX 10.20, 11.00, and
     11.11, and Solaris/SPARC 2.5.1, 2.6, 2.7, 8, and 9,

   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.


File: gccinstall.info,  Node: Specific,  Next: Old,  Prev: Binaries,  Up: Top

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

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

alpha*-*-*
==========

   This section contains general configuration information for all
alpha-based platforms using ELF (in particular, ignore this section for
DEC OSF/1, Digital UNIX and Tru64 UNIX).  In addition to reading this
section, please read all other sections that match your target.

   We require binutils 2.11.2 or newer.  Previous binutils releases had
a number of problems with DWARF 2 debugging information, not the least
of which is incorrect linking of shared libraries.

alpha*-dec-osf*
===============

   Systems using processors that implement the DEC Alpha architecture
and are running the DEC/Compaq Unix (DEC OSF/1, Digital UNIX, or Compaq
Tru64 UNIX) operating system, for example the DEC Alpha AXP systems.

   As of GCC 3.2, versions before `alpha*-dec-osf4' are no longer
supported.  (These are the versions which identify themselves as DEC
OSF/1.)

   In Digital Unix V4.0, virtual memory exhausted bootstrap failures
may be fixed by configuring with `--with-gc=simple', reconfiguring
Kernel Virtual Memory and Swap parameters per the `/usr/sbin/sys_check'
Tuning Suggestions, or applying the patch in
`http://gcc.gnu.org/ml/gcc/2002-08/msg00822.html'.

   In Tru64 UNIX V5.1, Compaq introduced a new assembler that does not
currently (2001-06-13) work with `mips-tfile'.  As a workaround, we
need to use the old assembler, invoked via the barely documented
`-oldas' option.  To bootstrap GCC, you either need to use the Compaq C
Compiler:

        % CC=cc SRCDIR/configure [OPTIONS] [TARGET]

   or you can use a copy of GCC 2.95.3 or higher built on Tru64 UNIX
V4.0:

        % CC=gcc -Wa,-oldas SRCDIR/configure [OPTIONS] [TARGET]

   As of GNU binutils 2.11.2, neither GNU `as' nor GNU `ld' are
supported on Tru64 UNIX, so you must not configure GCC with
`--with-gnu-as' or `--with-gnu-ld'.

   GCC writes a `.verstamp' directive to the assembler output file
unless it is built as a cross-compiler.  It gets the version to use from
the system header file `/usr/include/stamp.h'.  If you install a new
version of DEC Unix, you should rebuild GCC to pick up the new version
stamp.

   Note that since the Alpha is a 64-bit architecture, cross-compilers
from 32-bit machines will not generate code as efficient 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.  Building
cross-compilers on the Alpha for 32-bit machines has only been tested in
a few cases and may not work properly.

   `make compare' may fail on old versions of DEC Unix unless you add
`-save-temps' to `CFLAGS'.  On these systems, the name of the assembler
input file is stored in the object file, and that makes comparison fail
if it differs between the `stage1' and `stage2' compilations.  The
option `-save-temps' forces a fixed name to be used for the assembler
input file, instead of a randomly chosen name in `/tmp'.  Do not add
`-save-temps' unless the comparisons fail without that option.  If you
add `-save-temps', you will have to manually delete the `.i' and `.s'
files after each series of compilations.

   GCC now supports both the native (ECOFF) debugging format used by DBX
and GDB and an encapsulated STABS format for use only with GDB.  See the
discussion of the `--with-stabs' option of `configure' above for more
information on these formats and how to select them.

   There is a bug in DEC's assembler that produces incorrect line
numbers for ECOFF format when the `.align' directive is used.  To work
around this problem, GCC will not emit such alignment directives while
writing ECOFF format debugging information even if optimization is
being performed.  Unfortunately, this has the very undesirable
side-effect that code addresses when `-O' is specified are different
depending on whether or not `-g' is also specified.

   To avoid this behavior, specify `-gstabs+' and use GDB instead of
DBX.  DEC is now aware of this problem with the assembler and hopes to
provide a fix shortly.

alphaev5-cray-unicosmk*
=======================

   Cray T3E systems running Unicos/Mk.

   This port is incomplete and has many known bugs.  We hope to improve
the support for this target soon.  Currently, only the C front end is
supported, and it is not possible to build parallel applications.  Cray
modules are not supported; in particular, Craylibs are assumed to be in
`/opt/ctl/craylibs/craylibs'.

   You absolutely *must* use GNU make on this platform.  Also, you need
to tell GCC where to find the assembler and the linker.  The simplest
way to do so is by providing `--with-as' and `--with-ld' to
`configure', e.g.

         configure --with-as=/opt/ctl/bin/cam --with-ld=/opt/ctl/bin/cld \
           --enable-languages=c

   The comparison test during `make bootstrap' fails on Unicos/Mk
because the assembler inserts timestamps into object files.  You should
be able to work around this by doing `make all' after getting this
failure.

arc-*-elf
=========

   Argonaut ARC processor.  This configuration is intended for embedded
systems.

arm-*-elf
=========

xscale-*-*
==========

   ARM-family processors.  Subtargets that use the ELF object format
require GNU binutils 2.13 or newer.  Such subtargets include:
`arm-*-freebsd', `arm-*-netbsdelf', `arm-*-*linux', `arm-*-rtems' and
`arm-*-kaos'.

arm-*-coff
==========

   ARM-family processors.  Note that there are two different varieties
of PE format subtarget supported: `arm-wince-pe' and `arm-pe' as well
as a standard COFF target `arm-*-coff'.

arm-*-aout
==========

   ARM-family processors.  These targets support the AOUT file format:
`arm-*-aout', `arm-*-netbsd'.

avr
===

   ATMEL AVR-family micro controllers.  These are used in embedded
applications.  There are no standard Unix configurations.  *Note AVR
Options: (gcc)AVR Options, for the list of supported MCU types.

   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://www.openavr.org

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

   * http://www.amelek.gda.pl/avr/

   We _strongly_ recommend using binutils 2.13 or newer.

   The following error:
       Error: register required

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

c4x
===

   Texas Instruments TMS320C3x and TMS320C4x Floating Point Digital
Signal Processors.  These are used in embedded applications.  There are
no standard Unix configurations.  *Note TMS320C3x/C4x Options:
(gcc)TMS320C3x/C4x Options, for the list of supported MCU types.

   GCC can be configured as a cross compiler for both the C3x and C4x
architectures on the same system.  Use `configure --target=c4x
--enable-languages="c,c++"' to configure.

   Further installation notes and other useful information about C4x
tools can also be obtained from:

   * http://www.elec.canterbury.ac.nz/c4x/

CRIS
====

   CRIS is the CPU architecture in Axis Communications ETRAX
system-on-a-chip series.  These are used in embedded applications.

   *Note CRIS Options: (gcc)CRIS Options, for a list of CRIS-specific
options.

   There are a few different CRIS targets:
`cris-axis-aout'
     Old target.  Includes a multilib for the `elinux' a.out-based
     target.  No multilibs for newer architecture variants.

`cris-axis-elf'
     Mainly for monolithic embedded systems.  Includes a multilib for
     the `v10' core used in `ETRAX 100 LX'.

`cris-axis-linux-gnu'
     A GNU/Linux port for the CRIS architecture, currently targeting
     `ETRAX 100 LX' by default.

   For `cris-axis-aout' and `cris-axis-elf' you need binutils 2.11 or
newer.  For `cris-axis-linux-gnu' you need binutils 2.12 or newer.

   Pre-packaged tools can be obtained from
`ftp://ftp.axis.com/pub/axis/tools/cris/compiler-kit/'.  More
information about this platform is available at
`http://developer.axis.com/'.

DOS
===

   Please have a look at our binaries page.

   You cannot install GCC by itself on MSDOS; it will not compile under
any MSDOS compiler except itself.  You need to get the complete
compilation package DJGPP, which includes binaries as well as sources,
and includes all the necessary compilation tools and libraries.

dsp16xx
=======

   A port to the AT&T DSP1610 family of processors.

*-*-freebsd*
============

   The version of binutils installed in `/usr/bin' is known to work
unless otherwise specified in any per-architecture notes.  However,
binutils 2.12.1 or greater is known to improve overall testsuite
results.

   FreeBSD 1 is no longer supported.

   For FreeBSD 2 or any mutant a.out versions of FreeBSD 3: All
configuration support and files as shipped with GCC 2.95 are still in
place.  FreeBSD 2.2.7 has been known to bootstrap completely; however,
it is unknown which version of binutils was used (it is assumed that it
was the system copy in `/usr/bin') and C++ EH failures were noted.

   For FreeBSD using the ELF file format: DWARF 2 debugging is now the
default for all CPU architectures.  It had been the default on
FreeBSD/alpha since its inception.  You may use `-gstabs' instead of
`-g', if you really want the old debugging format.  There are no known
issues with mixing object files and libraries with different debugging
formats.  Otherwise, this release of GCC should now match more of the
configuration used in the stock FreeBSD configuration of GCC.  In
particular, `--enable-threads' is now configured by default.  However,
as a general user, do not attempt to replace the system compiler with
this release.  Known to bootstrap and check with good results on
FreeBSD 4.8-STABLE and 5-CURRENT.  In the past, known to bootstrap and
check with good results on FreeBSD 3.0, 3.4, 4.0, 4.2, 4.3, 4.4,
4.5-STABLE.

   In principle, `--enable-threads' is now compatible with
`--enable-libgcj' on FreeBSD.  However, it has only been built and
tested on `i386-*-freebsd[45]' and `alpha-*-freebsd[45]'.  The static
library may be incorrectly built (symbols are missing at link time).
There is a rare timing-based startup hang (probably involves an
assumption about the thread library).  Multi-threaded boehm-gc
(required for libjava) exposes severe threaded signal-handling bugs on
FreeBSD before 4.5-RELEASE.  Other CPU architectures supported by
FreeBSD will require additional configuration tuning in, at the very
least, both boehm-gc and libffi.

   Shared `libgcc_s.so' is now built and installed by default.

h8300-hms
=========

   Renesas H8/300 series of processors.

   Please have a look at our binaries page.

   The calling convention and structure layout has changed in release
2.6.  All code must be recompiled.  The calling convention now passes
the first three arguments in function calls in registers.  Structures
are no longer a multiple of 2 bytes.

hppa*-hp-hpux*
==============

   HP-UX version 9 or older is no longer supported.

   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 the pa-risc 2.0 architecture support with a 32-bit
runtime, you must use either the HP assembler, gas/binutils 2.11 or
newer, or a recent snapshot of gas.

   There are two default scheduling models for instructions.  These are
PROCESSOR_7100LC and PROCESSOR_8000.  They are selected from the pa-risc
architecture specified for the target machine when configuring.
PROCESSOR_8000 is the default.  PROCESSOR_7100LC is selected when the
target is a `hppa1*' machine.

   The PROCESSOR_8000 model is not well suited to older processors.
Thus, it is important to completely specify the machine architecture
when configuring if you want a model other than PROCESSOR_8000.  The
macro TARGET_SCHED_DEFAULT can be defined in BOOT_CFLAGS if a different
default scheduling model is desired.

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

hppa*-hp-hpux10
===============

   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.itrc.hp.com/service/home/home.do' US, Canada,
     Asia-Pacific, and Latin-America.

   * `http://europe.itrc.hp.com/service/home/home.do' Europe.

   The HP assembler on these systems 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'.

hppa*-hp-hpux11
===============

   GCC 3.0 and up support HP-UX 11.  On 64-bit capable systems, there
are two distinct ports.  The `hppa2.0w-hp-hpux11*' port generates code
for the 32-bit pa-risc runtime architecture.  It uses the HP linker.
The `hppa64-hp-hpux11*' port generates 64-bit code for the pa-risc 2.0
architecture.  The script config.guess now selects the port type based
on the type compiler detected during configuration.  You must set your
`PATH' or define `CC' so that configure finds an appropriate compiler
for the initial bootstrap.  Different prefixes must be used if both
ports are to be installed on the same system.

   It is best to explicitly configure the `hppa64-hp-hpux11*' target
with the `--with-ld=...' option.  We support both the HP and GNU
linkers for this target.  The two linkers require different link
commands.  Thus, it's not possible to switch linkers during a GCC
build.  This has been been reported to occur in a unified build of
binutils and GCC.

   GCC 2.95.x is not supported under HP-UX 11 and cannot be used to
compile GCC 3.0 and up.  Refer to binaries for information about
obtaining precompiled GCC binaries for HP-UX.

   You must use GNU binutils 2.11 or above with the 32-bit port.  Thread
support is not currently implemented, so `--enable-threads' does not
work.  See:

   * `http://gcc.gnu.org/ml/gcc-prs/2002-01/msg00551.html'

   * `http://gcc.gnu.org/ml/gcc-bugs/2002-01/msg00663.html'

   GCC 3.3 and later support weak symbols on the 32-bit port using SOM
secondary definition symbols.  This feature is not enabled for earlier
versions of HP-UX since there have been bugs in the linker support for
secondary symbols.  The HP linker patches `PHSS_26559' and `PHSS_24304'
for HP-UX 11.00 and 11.11, respectively, correct the problem of linker
core dumps creating C++ libraries.  Earlier patches may work but they
have not been tested.

   GCC 3.3 nows uses the ELF DT_INIT_ARRAY and DT_FINI_ARRAY capability
to run initializers and finalizers on the 64-bit port.  The feature
requires CVS binutils as of January 2, 2003, or a subsequent release to
correct a problem arising from HP's non-standard use of the .init and
.fini sections.  The 32-bit port uses the linker `+init' and `+fini'
options.  As with the support for secondary symbols, there have been
bugs in the order in which these options are executed by the HP linker.
So, again a recent linker patch is recommended.

   The HP assembler has many limitations and is not recommended for
either the 32 or 64-bit ports.  For example, it does not support weak
symbols or alias definitions.  As a result, explicit template
instantiations are required when using C++.  This will make it
difficult if not impossible to build many C++ applications.  You also
can't generate debugging information when using the HP assembler with
GCC.

   There are a number of issues to consider in selecting which linker to
use with the 64-bit port.  The  GNU 64-bit linker can only create
dynamic binaries.  The `-static' option causes linking with archive
libraries but doesn't produce a truly static binary.  Dynamic binaries
still require final binding by the dynamic loader to resolve a set of
dynamic-loader-defined symbols.  The default behavior of the HP linker
is the same as the GNU linker.  However, it can generate true 64-bit
static binaries using the `+compat' option.

   The HP 64-bit linker doesn't support linkonce semantics.  As a
result, C++ programs have many more sections than they should.

   The GNU 64-bit linker has some issues with shared library support
and exceptions.  As a result, we only support libgcc in archive format.
For similar reasons, dwarf2 unwind and exception support are disabled.
The GNU linker also has problems creating binaries with `-static'.  It
doesn't provide stubs for internal calls to global functions in shared
libraries, so these calls can't be overloaded.

   There are several possible approaches to building the distribution.
Binutils can be built first using the HP tools.  Then, the GCC
distribution can be built.  The second approach is to build GCC first
using the HP tools, then build binutils, then rebuild GCC.  There have
been problems with various binary distributions, so it is best not to
start from a binary distribution.

   Starting with GCC 3.4 an ISO C compiler is required to bootstrap.
The bundled compiler supports only traditional C; you will need either
HP's unbundled compiler, or a binary distribution of GCC.

   This port still is undergoing significant development.

i370-*-*
========

   This port is very preliminary and has many known bugs.  We hope to
have a higher-quality port for this machine soon.

*-*-linux-gnu
=============

   Versions of libstdc++-v3 starting with 3.2.1 require bugfixes present
in glibc 2.2.5 and later.  More information is available in the
libstdc++-v3 documentation.

   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.

   Currently Glibc 2.2.3 (and older releases) and GCC 3.0 are out of
sync since the latest exception handling changes for GCC.  Compiling
glibc with GCC 3.0 will give a binary incompatible glibc and therefore
cause lots of problems and might make your system completely unusable.
This will definitely need fixes in glibc but might also need fixes in
GCC.  We strongly advise to wait for glibc 2.2.4 and to read the
release notes of glibc 2.2.4 whether patches for GCC 3.0 are needed.
You can use glibc 2.2.3 with GCC 3.0, just do not try to recompile it.

i?86-*-linux*aout
=================

   Use this configuration to generate `a.out' binaries on Linux-based
GNU systems.  This configuration is being superseded.

i?86-*-linux*
=============

   As of GCC 3.3, binutils 2.13.1 or later is required for this
platform.  See bug 10877 for more information.

   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.

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

   Use this for the SCO OpenServer Release 5 family of operating
systems.

   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.

   GCC is now only supported on releases 5.0.4 and later, and requires
that you install Support Level Supplement OSS646B or later, and Support
Level Supplement OSS631C or later.  If you are using release 5.0.7 of
OpenServer, you must have at least the first maintenance pack installed
(this includes the relevant portions of OSS646).  OSS646, also known as
the "Execution Environment Update", provides updated link editors and
assemblers, as well as updated standard C and math libraries.  The C
startup modules are also updated to support the System V gABI draft, and
GCC relies on that behavior.  OSS631 provides a collection of commonly
used open source libraries, some of which GCC depends on (such as GNU
gettext and zlib).  SCO OpenServer Release 5.0.7 has all of this built
in by default, but OSS631C and later also apply to that release.  Please
visit ftp://ftp.sco.com/pub/openserver5 for the latest versions of
these (and other potentially useful) supplements.

   Although there is support for using the native assembler, it is
recommended that you configure GCC to use the GNU assembler.  You do
this by using the flags `--with-gnu-as'.  You should use a modern
version of GNU binutils.  Version 2.13.2.1 was used for all testing.
In general, only the `--with-gnu-as' option is tested.  A modern
bintuils (as well as a plethora of other development related GNU
utilities) can be found in Support Level Supplement OSS658A, the "GNU
Development Tools" package.  See the SCO web and ftp sites for details.
That package also contains the currently "officially supported" version
of GCC, version 2.95.3.  It is useful for bootstrapping this version.

i?86-*-udk
==========

   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.

   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 /YOUR/PATH/TO/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._

   After the usual `make bootstrap' and `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.

ia64-*-linux
============

   IA-64 processor (also known as IPF, or Itanium Processor Family)
running GNU/Linux.

   None of the following versions of GCC has an ABI that is compatible
with any of the other versions in this list, with the exception that
Red Hat 2.96 and Trillian 000171 are compatible with each other: 3.1,
3.0.2, 3.0.1, 3.0, Red Hat 2.96, and Trillian 000717.  This primarily
affects C++ programs and programs that create shared libraries.  GCC
3.1 or later is recommended for compiling linux, the kernel.  As of
version 3.1 GCC is believed to be fully ABI compliant, and hence no
more major ABI changes are expected.

ia64-*-hpux*
============

   Building GCC on this target requires the GNU Assembler. The bundled
HP assembler will not work. To prevent GCC from using the wrong
assembler, the option `--with-gnu-as' may be necessary.

   The GCC libunwind library has not been ported to HPUX. This means
that for GCC versions 3.2.3 and earlier, `--enable-libunwind-exceptions'
is required to build GCC. For GCC 3.3 and later, this is the default.

*-ibm-aix*
==========

   AIX version 3 or older is no longer supported.

   AIX Make frequently has problems with GCC makefiles.  GNU Make
3.79.1 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).

   The native `as' and `ld' are recommended for bootstrapping on AIX 4
and required for bootstrapping on AIX 5L.  The GNU Assembler reports
that it supports WEAK symbols on AIX 4, which causes GCC to try to
utilize weak symbol functionality although it is not supported.  The GNU
Assembler and Linker do not support AIX 5L sufficiently to bootstrap
GCC.  The native AIX tools do interoperate with GCC.

   Building `libstdc++.a' requires a fix for an AIX Assembler bug APAR
IY26685 (AIX 4.3) or APAR IY25528 (AIX 5.1).

   `libstdc++' in GCC 3.2 increments the major version number of the
shared object and GCC installation places the `libstdc++.a' shared
library in a common location which will overwrite the GCC 3.1 version
of the shared library.  Applications either need to be re-linked
against the new shared library or the GCC 3.1 version of the
`libstdc++' shared object needs to be available to the AIX runtime
loader.  The GCC 3.1 `libstdc++.so.4' shared object can be installed
for runtime dynamic loading using the following steps to set the
`F_LOADONLY' flag in the shared object for _each_ multilib
`libstdc++.a' installed:

   Extract the shared object from each the GCC 3.1 `libstdc++.a'
archive:
        % ar -x libstdc++.a libstdc++.so.4

   Enable the `F_LOADONLY' flag so that the shared object will be
available for runtime dynamic loading, but not linking:
        % strip -e libstdc++.so.4

   Archive the runtime-only shared object in the GCC 3.2 `libstdc++.a'
archive:
        % ar -q libstdc++.a libstdc++.so.4

   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 and above.

   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
techsupport.services.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
techsupport.services.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 techsupport.services.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 encounters this problem, set the
`LANG' environment variable to `C' or `En_US'.

   By default, GCC for AIX 4.1 and above produces code that can be used
on both Power or PowerPC processors.

   A default can be specified with the `-mcpu=CPU_TYPE' switch and
using the configure option `--with-cpu-CPU_TYPE'.

ip2k-*-elf
==========

   Ubicom IP2022 micro controller.  This configuration is intended for
embedded systems.  There are no standard Unix configurations.

   Use `configure --target=ip2k-elf --enable-languages=c' to configure
GCC.

iq2000-*-elf
============

   Vitesse IQ2000 processors.  These are used in embedded applications.
There are no standard Unix configurations.

m32r-*-elf
==========

   Renesas M32R processor.  This configuration is intended for embedded
systems.

m6811-elf
=========

   Motorola 68HC11 family micro controllers.  These are used in embedded
applications.  There are no standard Unix configurations.

m6812-elf
=========

   Motorola 68HC12 family micro controllers.  These are used in embedded
applications.  There are no standard Unix configurations.

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 GCC.  This bug
manifests itself during the first stage of compilation, while building
`libgcc2.a':

     _floatdisf
     cc1: warning: `-g' option not supported on this version of GCC
     cc1: warning: `-g1' option not supported on this version of GCC
     ./xgcc: Internal compiler error: program as got fatal signal 11

   A patched version of the assembler is available as the file
`ftp://altdorf.ai.mit.edu/archive/cph/hpux-8.0-assembler'.  If you have
HP software support, the patch can also be obtained directly from HP,
as described in the following note:

     This is the patched assembler, to patch SR#1653-010439, where the
     assembler aborts on floating point constants.

     The bug is not really in the assembler, but in the shared library
     version of the function "cvtnum(3c)".  The bug on "cvtnum(3c)" is
     SR#4701-078451.  Anyway, the attached assembler uses the archive
     library version of "cvtnum(3c)" and thus does not exhibit the bug.

   This patch is also known as PHCO_4484.

   In addition gdb does not understand that native HP-UX format, so you
must use gas if you wish to use gdb.

   On HP-UX version 8.05, but not on 8.07 or more recent versions, the
`fixproto' shell script triggers a bug in the system shell.  If you
encounter this problem, upgrade your operating system or use BASH (the
GNU shell) to run `fixproto'.  This bug will cause the fixproto program
to report an error of the form:

     ./fixproto: sh internal 1K buffer overflow

   To fix this, you can also change the first line of the fixproto
script to look like:

     #!/bin/ksh

mips-*-*
========

   If on a MIPS system you get an error message saying "does not have gp
sections for all it's [sic] sectons [sic]", don't worry about it.  This
happens whenever you use GAS with the MIPS linker, but there is not
really anything wrong, and it is okay to use the output file.  You can
stop such warnings by installing the GNU linker.

   It would be nice to extend GAS to produce the gp tables, but they are
optional, and there should not be a warning about their absence.

   The libstdc++ atomic locking routines for MIPS targets requires MIPS
II and later.  A patch went in just after the GCC 3.3 release to make
`mips*-*-*' use the generic implementation instead.  You can also
configure for `mipsel-elf' as a workaround.  The `mips*-*-linux*'
target continues to use the MIPS II routines.  More work on this is
expected in future releases.

mips-sgi-irix5
==============

   This configuration has considerable problems, which will be fixed in
a future release.

   In order to compile GCC on an SGI running IRIX 5, the
"compiler_dev.hdr" subsystem must be installed from the IDO CD-ROM
supplied by Silicon Graphics.  It is also available for download from
http://www.sgi.com/developers/devtools/apis/ido.html.

   `make compare' may fail on version 5 of IRIX unless you add
`-save-temps' to `CFLAGS'.  On these systems, the name of the assembler
input file is stored in the object file, and that makes comparison fail
if it differs between the `stage1' and `stage2' compilations.  The
option `-save-temps' forces a fixed name to be used for the assembler
input file, instead of a randomly chosen name in `/tmp'.  Do not add
`-save-temps' unless the comparisons fail without that option.  If you
do you `-save-temps', you will have to manually delete the `.i' and
`.s' files after each series of compilations.

   If you use the MIPS C compiler to bootstrap, it may be necessary to
increase its table size for switch statements with the `-Wf,-XNg1500'
option.  If you use the `-O2' optimization option, you also need to use
`-Olimit 3000'.

   To enable debugging under IRIX 5, you must use GNU `as' 2.11.2 or
later, and use the `--with-gnu-as' configure option when configuring
GCC.  GNU `as' is distributed as part of the binutils package.  When
using release 2.11.2, you need to apply a patch
http://sources.redhat.com/ml/binutils/2001-07/msg00352.html which will
be included in the next release of binutils.

   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.

mips-sgi-irix6
==============

   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 ...

   or

     test.o: ELF 64-bit MSB ...

   then your version of `cc' uses the O32 or N64 ABI by default.  You
should set the environment variable `CC' to `cc -n32' before
configuring GCC.

   If you want the resulting `gcc' to run on old 32-bit systems with
the MIPS R4400 CPU, you need to ensure that only code for the mips3
instruction set architecture (ISA) is generated.  While GCC 3.x does
this correctly, both GCC 2.95 and SGI's MIPSpro `cc' may change the ISA
depending on the machine where GCC is built.  Using one of them as the
bootstrap compiler may result in mips4 code, which won't run at all on
mips3-only systems.  For the test program above, you should see:

     test.o: ELF N32 MSB mips-3 ...

   If you get:

     test.o: ELF N32 MSB mips-4 ...

   instead, you should set the environment variable `CC' to `cc -n32
-mips3' or `gcc -mips3' respectively before configuring GCC.

   GCC on IRIX 6 is usually built to support both the N32 and N64 ABIs.
If you build GCC on a system that doesn't have the N64 libraries
installed, you need to configure with `--disable-multilib' so GCC
doesn't try to use them.  Look for `/usr/lib64/libc.so.1' to see if you
have the 64-bit libraries installed.

   You must _not_ use GNU `as' (which isn't built anyway as of binutils
2.11.2) on IRIX 6 platforms; doing so will only cause problems.

   GCC does not currently support generating O32 ABI binaries in the
`mips-sgi-irix6' configurations.  It is possible to create a GCC with
O32 ABI only support by configuring it for the `mips-sgi-irix5' target
and using a patched GNU `as' 2.11.2 as documented in the
`mips-sgi-irix5' section above.  Using the native assembler requires
patches to GCC which will be included in a future release.  It is
expected that O32 ABI support will be available again in a future
release.

   The `--enable-threads' option doesn't currently work, a patch is in
preparation for a future release.  The `--enable-libgcj' option is
disabled by default: IRIX 6 uses a very low default limit (20480) for
the command line length.  Although libtool contains a workaround for
this problem, at least the N64 `libgcj' is known not to build despite
this, running into an internal error of the native `ld'.  A sure fix is
to increase this limit (`ncargs') to its maximum of 262144 bytes.  If
you have root access, you can use the `systune' command to do this.

   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.  Currently
this is known to affect `inet_ntoa', `inet_lnaof', `inet_netof',
`inet_makeaddr', and `semctl'.  Until the bug is fixed, GCC contains
workarounds for the known affected functions.

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

powerpc-*-*
===========

   You can specify a default version for the `-mcpu=CPU_TYPE' switch by
using the configure option `--with-cpu-CPU_TYPE'.

powerpc-*-darwin*
=================

   PowerPC running Darwin (Mac OS X kernel).

   Pre-installed versions of Mac OS X may not include any developer
tools, meaning that you will not be able to build GCC from source.  Tool
binaries are available at
`http://developer.apple.com/tools/compilers.html' (free registration
required).

   The default stack limit of 512K is too small, which may cause
compiles to fail with 'Bus error'.  Set the stack larger, for instance
by doing `limit stack 800'.  It's a good idea to use the GNU
preprocessor instead of Apple's `cpp-precomp' during the first stage of
bootstrapping; this is automatic when doing `make bootstrap', but to do
it from the toplevel objdir you will need to say `make CC='cc
-no-cpp-precomp' bootstrap'.

   The version of GCC shipped by Apple typically includes a number of
extensions not available in a standard GCC release.  These extensions
are generally specific to Mac programming.

powerpc-*-elf, powerpc-*-sysv4
==============================

   PowerPC system in big endian mode, running System V.4.

powerpc-*-linux-gnu*
====================

   You will need binutils 2.13.90.0.10 or newer for a working GCC.

powerpc-*-netbsd*
=================

   PowerPC system in big endian mode running NetBSD.  To build the
documentation you will need Texinfo version 4.2 (NetBSD 1.5.1 included
Texinfo version 3.12).

powerpc-*-eabisim
=================

   Embedded PowerPC system in big endian mode for use in running under
the PSIM simulator.

powerpc-*-eabi
==============

   Embedded PowerPC system in big endian mode.

powerpcle-*-elf, powerpcle-*-sysv4
==================================

   PowerPC system in little endian mode, running System V.4.

powerpcle-*-eabisim
===================

   Embedded PowerPC system in little endian mode for use in running
under the PSIM simulator.

powerpcle-*-eabi
================

   Embedded PowerPC system in little endian mode.

s390-*-linux*
=============

   S/390 system running Linux for S/390.

s390x-*-linux*
==============

   zSeries system (64-bit) running Linux for zSeries.

*-*-solaris2*
=============

   Sun does not ship a C compiler with Solaris 2.  To bootstrap and
install GCC you first have to install a pre-built compiler, see our
binaries page for details.

   The Solaris 2 `/bin/sh' will often fail to configure `libstdc++-v3',
`boehm-gc' or `libjava'.  We therefore recommend to use the following
sequence of commands to bootstrap and install GCC:

        % CONFIG_SHELL=/bin/ksh
        % export CONFIG_SHELL

   and then proceed as described in the build instructions, where we
strongly recommend using GNU make and specifying an absolute path to
invoke SRCDIR/configure.

   Solaris 2 comes with a number of optional OS packages.  Some of these
are needed to use GCC fully, namely `SUNWarc', `SUNWbtool', `SUNWesu',
`SUNWhea', `SUNWlibm', `SUNWsprot', and `SUNWtoo'.  If you did not
install all optional packages when installing Solaris 2, you will need
to verify that the packages that GCC needs are installed.

   To check whether an optional package is installed, use the `pkginfo'
command.  To add an optional package, use the `pkgadd' command.  For
further details, see the Solaris 2 documentation.

   Trying to use the linker and other tools in `/usr/ucb' to install
GCC has been observed to cause trouble.  For example, the linker may
hang indefinitely.  The fix is to remove `/usr/ucb' from your `PATH'.

   The build process works more smoothly with the legacy Sun tools so,
if you have `/usr/xpg4/bin' in your `PATH', we recommend that you place
`/usr/bin' before `/usr/xpg4/bin' for the duration of the build.

   All releases of GNU binutils prior to 2.11.2 have known bugs on this
platform.  We recommend the use of GNU binutils 2.11.2 or the vendor
tools (Sun `as', Sun `ld').

   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 (invalid) constructs with the option
`-fpermissive'; it will assume that any missing type is `int' (as
defined by C89).

   There are patches for Solaris 2.6 (105633-56 or newer for SPARC,
106248-42 or newer for Intel), Solaris 7 (108376-21 or newer for SPARC,
108377-20 for Intel), and Solaris 8 (108652-24 or newer for SPARC,
108653-22 for Intel) that fix this bug.

sparc-sun-solaris2*
===================

   When GCC is configured to use binutils 2.11.2 or later the binaries
produced are smaller than the ones produced using Sun's native tools;
this difference is quite significant for binaries containing debugging
information.

   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 for
Solaris 2.6 and has been fixed in later (5.x) versions of the assembler,
starting with Solaris 7.

   Starting with Solaris 7, the operating system is capable of executing
64-bit SPARC V9 binaries.  GCC 3.1 and later properly supports this;
the `-m64' option enables 64-bit code generation.  However, if all you
want is code tuned for the UltraSPARC CPU, you should try the
`-mtune=ultrasparc' option instead, which produces code that, unlike
full 64-bit code, can still run on non-UltraSPARC machines.

   When configuring on a Solaris 7 or later system that is running a
kernel that supports only 32-bit binaries, one must configure with
`--disable-multilib', since we will not be able to build the 64-bit
target libraries.

sparc-sun-solaris2.7
====================

   Sun patch 107058-01 (1999-01-13) for Solaris 7/SPARC 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 7-based hosts, so
     you may have to back it out.

   * Copy the original, unpatched Solaris 7 `/usr/ccs/bin/as' into
     `/usr/local/libexec/gcc/sparc-sun-solaris2.7/3.4/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.  The current (as of
     2001-09-24) revision is -14, and is included in the Solaris 7
     Recommended Patch Cluster.

   GCC 3.3 triggers a bug in version 5.0 Alpha 03/27/98 of the Sun
assembler, which causes a bootstrap failure when linking the 64-bit
shared version of libgcc. A typical error message is:

     ld: fatal: relocation error: R_SPARC_32: file libgcc/sparcv9/_muldi3.o:
       symbol <unknown>:  offset 0xffffffff7ec133e7 is non-aligned.

   This bug has been fixed in the final 5.0 version of the assembler.

sparc-*-linux*
==============

   GCC versions 3.0 and higher require binutils 2.11.2 and glibc 2.2.4
or newer on this platform.  All earlier binutils and glibc releases
mishandled unaligned relocations on `sparc-*-*' targets.

sparc64-*-solaris2*
===================

   The following compiler flags must be specified in the configure step
in order to bootstrap this target with the Sun compiler:

        % CC="cc -xildoff -xarch=v9" SRCDIR/configure [OPTIONS] [TARGET]

   `-xildoff' turns off the incremental linker, and `-xarch=v9'
specifies the SPARC-V9 architecture to the Sun linker and assembler.

sparcv9-*-solaris2*
===================

   This is a synonym for sparc64-*-solaris2*.

*-*-sysv*
=========

   On System V release 3, you may get this error message while linking:

     ld fatal: failed to write symbol name SOMETHING
      in strings table for file WHATEVER

   This probably indicates that the disk is full or your ulimit won't
allow the file to be as large as it needs to be.

   This problem can also result because the kernel parameter `MAXUMEM'
is too small.  If so, you must regenerate the kernel and make the value
much larger.  The default value is reported to be 1024; a value of 32768
is said to work.  Smaller values may also work.

   On System V, if you get an error like this,

     /usr/local/lib/bison.simple: In function `yyparse':
     /usr/local/lib/bison.simple:625: virtual memory exhausted

that too indicates a problem with disk space, ulimit, or `MAXUMEM'.

   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.

vax-dec-ultrix
==============

   Don't try compiling with VAX C (`vcc').  It produces incorrect code
in some cases (for example, when `alloca' is used).

*-*-vxworks*
============

   Support for VxWorks is in flux.  At present GCC supports _only_ the
very recent VxWorks 5.5 (aka Tornado 2.2) release, and only on PowerPC.
We welcome patches for other architectures supported by VxWorks 5.5.
Support for VxWorks AE would also be welcome; we believe this is merely
a matter of writing an appropriate "configlette" (see below).  We are
not interested in supporting older, a.out or COFF-based, versions of
VxWorks in GCC 3.

   VxWorks comes with an older version of GCC installed in
`$WIND_BASE/host'; we recommend you do not overwrite it.  Choose an
installation PREFIX entirely outside $WIND_BASE.  Before running
`configure', create the directories `PREFIX' and `PREFIX/bin'.  Link or
copy the appropriate assembler, linker, etc. into `PREFIX/bin', and set
your PATH to include that directory while running both `configure' and
`make'.

   You must give `configure' the `--with-headers=$WIND_BASE/target/h'
switch so that it can find the VxWorks system headers.  Since VxWorks
is a cross compilation target only, you must also specify
`--target=TARGET'.  `configure' will attempt to create the directory
`PREFIX/TARGET/sys-include' and copy files into it; make sure the user
running `configure' has sufficient privilege to do so.

   GCC's exception handling runtime requires a special "configlette"
module, `contrib/gthr_supp_vxw_5x.c'.  Follow the instructions in that
file to add the module to your kernel build.  (Future versions of
VxWorks will incorporate this module.)

xtensa-*-elf
============

   This target is intended for embedded Xtensa systems using the
`newlib' C library.  It uses ELF but does not support shared objects.
Designed-defined instructions specified via the Tensilica Instruction
Extension (TIE) language are only supported through inline assembly.

   The Xtensa configuration information must be specified prior to
building GCC.  The `include/xtensa-config.h' header file contains the
configuration information.  If you created your own Xtensa
configuration with the Xtensa Processor Generator, the downloaded files
include a customized copy of this header file, which you can use to
replace the default header file.

xtensa-*-linux*
===============

   This target is for Xtensa systems running GNU/Linux.  It supports ELF
shared objects and the GNU C library (glibc).  It also generates
position-independent code (PIC) regardless of whether the `-fpic' or
`-fPIC' options are used.  In other respects, this target is the same
as the `xtensa-*-elf' target.

Microsoft Windows (32-bit)
==========================

   A port of GCC 2.95.2 and 3.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 build with Microsoft's C++ compiler and there
are no plans to make it do so.

OS/2
====

   GCC does not currently support OS/2.  However, Andrew Zabolotny has
been working on a generic OS/2 port with pgcc.  The current 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/.

Older systems
=============

   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.

   Starting with GCC 3.1, each release has a list of "obsoleted"
systems.  Support for these systems is still present in that release,
but `configure' will fail unless the `--enable-obsolete' option is
given.  Unless a maintainer steps forward, support for these systems
will be removed from the next release of GCC.

   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.

   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.

   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.

all ELF targets (SVR4, Solaris 2, etc.)
=======================================

   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.

