Configuring egcs
Like most GNU software, egcs must be configured before it can be
built. This document attempts to describe the recommended
configuration procedure for both native and cross targets.
We use _srcdir_ to refer to the toplevel source directory for egcs; we
use _objdir_ to refer to the toplevel build/object directory for egcs.
First, we _highly_ recommend that egcs be built into a separate
directory than the sources which does _not_ reside within the source
tree. This is how we generally build egcs; 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 egcs:
% mkdir _objdir_
% cd _objdir_
% _srcdir_/configure _[target]_ _[options]_
_target specification_
* egcs 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 when configuring a cross compiler;
examples of valid targets would be i960-rtems, m68k-coff, sh-elf,
etc.
_options specification_
Use _options_ to override several configure time options for egcs. 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
only effects the Objective-C compiler and runtime library.
* --enable-threads=_lib_ -- Specify that _lib_ is the thread support
library. This only effects the Objective-C compiler and runtime
library.
* --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 optimzied 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 is still under
development, but may be useful in limited situations. This option
is never enabled by default.
* --with-fast-fixincludes -- Specify that a newer and faster method
of fixing the system header files should be used. This feature is
still under development, but we are interested in feedback from
folks that want to try it. This option is never enabled by
default..
* --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
egcs/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 egcs source tree:
grep language= */config-lang.in
Currently, you can use any of the following: CHILL, c++, f77, java
and objc. Please note, that this switch will only work with recent
snapshots (for instance, newer snapshots than 19981126 should do);
it does not work with any egcs releases up to and including 1.1.1,
though!
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. These include files will be copied into the egcs
install directory. Fixincludes will be run on these files to make
them compatible with egcs.
* --with-libs=_dirs_ -- Specifies a list of directories which
contain the target runtime libraries. These libraries will be
copied into the egcs 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.
_________________________________________________________________
_Last modified on Dec 6, 1998._