OpenBSD-4.6/gnu/egcs/install/CONFIGURE
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.
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 _prefix_ 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-local-prefix=_dirname_ -- Specify the installation
directory for local include files. The default is /usr/local.
+ --with-gxx-include-dir=_dirname_ -- Specify the installation
directory for g++ header files. The default is
/usr/local/include/g++.
* --enable-shared -- Build shared versions of the C++ runtime
libraries if supported --disable-shared is the default.
* --enable-haifa -- Enable the new Haifa instruction scheduler in
the compiler; the new scheduler can significantly improve code on
some targets.
For EGCS 1.0.x releases --disable-haifa is the default on all
platforms except the HPPA.
For newer releases --disable-haifa is the default on all platforms
except the alpha, hppa, powerpc, rs6000, SPARC and m32r.
* --with-gnu-as -- Specify that the compiler should assume the GNU
assembler (aka gas) is available.
* --with-gnu-ld -- Specify that the compiler should assume the GNU
linker (aka gld) is available.
* --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.
* --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.
* --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.
* --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 _lang_x 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!
* --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.
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[1]Return to the GCC Installation page
References
1. http://gcc.gnu.org/install/index.html