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[gcc.git] / INSTALL / CONFIGURE

Configuring egcs-1.0

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.  This is how we generally build egcs; building
where srcdir == objdir should still work, but doesn't get
extensive testing.

Second, when configuring a native system, either "cc" 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.

  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.
  --disable-haifa is currently the default on all platforms except the HPPA.

  --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
  RS6000/PowerPC ports.


Some options which only apply to building cross compilers:

  --with-headers=dir -- Specifies a directory which has target
  include files.
  --with-libs=dirs -- Specifies a list of directories which contain
  the target runtime libraries.
  --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 December 2, 1997.