Info file gcc.info, produced by Makeinfo, -*- Text -*- from input
file gcc.texinfo.

   This file documents the use and the internals of the GNU compiler.

   Copyright (C) 1988, 1989, 1990 Free Software Foundation, Inc.

   Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.

   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the sections entitled "GNU General Public License" and "Protect
Your Freedom--Fight `Look And Feel'" are included exactly as in the
original, and provided that the entire resulting derived work is
distributed under the terms of a permission notice identical to this
one.

   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the sections entitled "GNU General Public
License" and "Protect Your Freedom--Fight `Look And Feel'" and this
permission notice may be included in translations approved by the
Free Software Foundation instead of in the original English.


File: gcc.info,  Node: Top,  Next: Copying,  Up: (DIR)

Introduction
************

   This manual documents how to run, install and port the GNU C
compiler, as well as its new features and incompatibilities, and how
to report bugs.

* Menu:

* Copying::         GNU General Public License says
                     how you can copy and share GNU CC.
* Contributors::    People who have contributed to GNU CC.
* Boycott::	    Protect your freedom--fight "look and feel".
* Options::         Command options supported by `gcc'.
* Installation::    How to configure, compile and install GNU CC.
* Trouble::         If you have trouble installing GNU CC.
* Service::         How to find suppliers of services for GNU CC users.
* Incompatibilities:: Incompatibilities of GNU CC.
* Extensions::      GNU extensions to the C language.
* Bugs::            How to report bugs (if you want to get them fixed).
* Portability::     Goals of GNU CC's portability features.
* Interface::       Function-call interface of GNU CC output.
* Passes::          Order of passes, what they do, and what each file is for.
* RTL::             The intermediate representation that most passes work on.
* Machine Desc::    How to write machine description instruction patterns.
* Machine Macros::  How to write the machine description C macros.
* Config::          Writing the `xm-MACHINE.h' file.


File: gcc.info,  Node: Copying,  Next: Contributors,  Prev: Top,  Up: Top

GNU GENERAL PUBLIC LICENSE
**************************

                           Version 1, February 1989

     Copyright (C) 1989 Free Software Foundation, Inc.
     675 Mass Ave, Cambridge, MA 02139, USA
     
     Everyone is permitted to copy and distribute verbatim copies
     of this license document, but changing it is not allowed.

Preamble
========

   The license agreements of most software companies try to keep
users at the mercy of those companies.  By contrast, our General
Public License is intended to guarantee your freedom to share and
change free software--to make sure the software is free for all its
users.  The General Public License applies to the Free Software
Foundation's software and to any other program whose authors commit
to using it.  You can use it for your programs, too.

   When we speak of free software, we are referring to freedom, not
price.  Specifically, the General Public License is designed to make
sure that you have the freedom to give away or sell copies of free
software, that you receive source code or can get it if you want it,
that you can change the software or use pieces of it in new free
programs; and that you know you can do these things.

   To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if
you distribute copies of the software, or if you modify it.

   For example, if you distribute copies of a such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have.  You must make sure that they, too, receive or can get the
source code.  And you must tell them their rights.

   We protect your rights with two steps: (1) copyright the software,
and (2) offer you this license which gives you legal permission to
copy, distribute and/or modify the software.

   Also, for each author's protection and ours, we want to make
certain that everyone understands that there is no warranty for this
free software.  If the software is modified by someone else and
passed on, we want its recipients to know that what they have is not
the original, so that any problems introduced by others will not
reflect on the original authors' reputations.

   The precise terms and conditions for copying, distribution and
modification follow.

                             TERMS AND CONDITIONS

  1. This License Agreement applies to any program or other work
     which contains a notice placed by the copyright holder saying it
     may be distributed under the terms of this General Public
     License.  The "Program", below, refers to any such program or
     work, and a "work based on the Program" means either the Program
     or any work containing the Program or a portion of it, either
     verbatim or with modifications.  Each licensee is addressed as
     "you".

  2. You may copy and distribute verbatim copies of the Program's
     source code as you receive it, in any medium, provided that you
     conspicuously and appropriately publish on each copy an
     appropriate copyright notice and disclaimer of warranty; keep
     intact all the notices that refer to this General Public License
     and to the absence of any warranty; and give any other
     recipients of the Program a copy of this General Public License
     along with the Program.  You may charge a fee for the physical
     act of transferring a copy.

  3. You may modify your copy or copies of the Program or any portion
     of it, and copy and distribute such modifications under the
     terms of Paragraph 1 above, provided that you also do the
     following:

        * cause the modified files to carry prominent notices stating
          that you changed the files and the date of any change; and

        * cause the whole of any work that you distribute or publish,
          that in whole or in part contains the Program or any part
          thereof, either with or without modifications, to be
          licensed at no charge to all third parties under the terms
          of this General Public License (except that you may choose
          to grant warranty protection to some or all third parties,
          at your option).

        * If the modified program normally reads commands
          interactively when run, you must cause it, when started
          running for such interactive use in the simplest and most
          usual way, to print or display an announcement including an
          appropriate copyright notice and a notice that there is no
          warranty (or else, saying that you provide a warranty) and
          that users may redistribute the program under these
          conditions, and telling the user how to view a copy of this
          General Public License.

        * You may charge a fee for the physical act of transferring a
          copy, and you may at your option offer warranty protection
          in exchange for a fee.

        Mere aggregation of another independent work with the Program
     (or its derivative) on a volume of a storage or distribution
     medium does not bring the other work under the scope of these
     terms.

  4. You may copy and distribute the Program (or a portion or
     derivative of it, under Paragraph 2) in object code or
     executable form under the terms of Paragraphs 1 and 2 above
     provided that you also do one of the following:

        * accompany it with the complete corresponding
          machine-readable source code, which must be distributed
          under the terms of Paragraphs 1 and 2 above; or,

        * accompany it with a written offer, valid for at least three
          years, to give any third party free (except for a nominal
          charge for the cost of distribution) a complete
          machine-readable copy of the corresponding source code, to
          be distributed under the terms of Paragraphs 1 and 2 above;
          or,

        * accompany it with the information you received as to where
          the corresponding source code may be obtained.  (This
          alternative is allowed only for noncommercial distribution
          and only if you received the program in object code or
          executable form alone.)

        Source code for a work means the preferred form of the work
     for making modifications to it.  For an executable file,
     complete source code means all the source code for all modules
     it contains; but, as a special exception, it need not include
     source code for modules which are standard libraries that
     accompany the operating system on which the executable file
     runs, or for standard header files or definitions files that
     accompany that operating system.

  5. You may not copy, modify, sublicense, distribute or transfer the
     Program except as expressly provided under this General Public
     License.  Any attempt otherwise to copy, modify, sublicense,
     distribute or transfer the Program is void, and will
     automatically terminate your rights to use the Program under
     this License.  However, parties who have received copies, or
     rights to use copies, from you under this General Public License
     will not have their licenses terminated so long as such parties
     remain in full compliance.

  6. By copying, distributing or modifying the Program (or any work
     based on the Program) you indicate your acceptance of this
     license to do so, and all its terms and conditions.

  7. Each time you redistribute the Program (or any work based on the
     Program), the recipient automatically receives a license from
     the original licensor to copy, distribute or modify the Program
     subject to these terms and conditions.  You may not impose any
     further restrictions on the recipients' exercise of the rights
     granted herein.

  8. The Free Software Foundation may publish revised and/or new
     versions of the General Public License from time to time.  Such
     new versions will be similar in spirit to the present version,
     but may differ in detail to address new problems or concerns.

        Each version is given a distinguishing version number.  If
     the Program specifies a version number of the license which
     applies to it and "any later version", you have the option of
     following the terms and conditions either of that version or of
     any later version published by the Free Software Foundation.  If
     the Program does not specify a version number of the license,
     you may choose any version ever published by the Free Software
     Foundation.

  9. If you wish to incorporate parts of the Program into other free
     programs whose distribution conditions are different, write to
     the author to ask for permission.  For software which is
     copyrighted by the Free Software Foundation, write to the Free
     Software Foundation; we sometimes make exceptions for this.  Our
     decision will be guided by the two goals of preserving the free
     status of all derivatives of our free software and of promoting
     the sharing and reuse of software generally.

                                      NO WARRANTY

 10. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO
     WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE
     LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
     HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT
     WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
     BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
     AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS TO THE
     QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE
     PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY
     SERVICING, REPAIR OR CORRECTION.

 11. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
     WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY
     MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE
     LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL,
     INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR
     INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS
     OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
     YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH
     ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN
     ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

                         END OF TERMS AND CONDITIONS

Appendix: How to Apply These Terms to Your New Programs
=======================================================

   If you develop a new program, and you want it to be of the
greatest possible use to humanity, the best way to achieve this is to
make it free software which everyone can redistribute and change
under these terms.

   To do so, attach the following notices to the program.  It is
safest to attach them to the start of each source file to most
effectively convey the exclusion of warranty; and each file should
have at least the "copyright" line and a pointer to where the full
notice is found.

     ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES.
     Copyright (C) 19YY  NAME OF AUTHOR
     
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 1, or (at your option)
     any later version.
     
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
     
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

   Also add information on how to contact you by electronic and paper
mail.

   If the program is interactive, make it output a short notice like
this when it starts in an interactive mode:

     Gnomovision version 69, Copyright (C) 19YY NAME OF AUTHOR
     Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
     This is free software, and you are welcome to redistribute it
     under certain conditions; type `show c' for details.

   The hypothetical commands `show w' and `show c' should show the
appropriate parts of the General Public License.  Of course, the
commands you use may be called something other than `show w' and
`show c'; they could even be mouse-clicks or menu items--whatever
suits your program.

   You should also get your employer (if you work as a programmer) or
your school, if any, to sign a "copyright disclaimer" for the
program, if necessary.  Here a sample; alter the names:

     Yoyodyne, Inc., hereby disclaims all copyright interest in the
     program `Gnomovision' (a program to direct compilers to make passes
     at assemblers) written by James Hacker.
     
     SIGNATURE OF TY COON, 1 April 1989
     Ty Coon, President of Vice

   That's all there is to it!


File: gcc.info,  Node: Contributors,  Next: Boycott,  Prev: Copying,  Up: Top

Contributors to GNU CC
**********************

   In addition to Richard Stallman, several people have written parts
of GNU CC.

   * The idea of using RTL and some of the optimization ideas came
     from the U. of Arizona Portable Optimizer, written by Jack
     Davidson and Christopher Fraser.  See "Register Allocation and
     Exhaustive Peephole Optimization", Software Practice and
     Experience 14 (9), Sept. 1984, 857-866.

   * Paul Rubin wrote most of the preprocessor.

   * Leonard Tower wrote parts of the parser, RTL generator, and RTL
     definitions, and of the Vax machine description.

   * Ted Lemon wrote parts of the RTL reader and printer.

   * Jim Wilson implemented loop strength reduction and some other
     loop optimizations.

   * Nobuyuki Hikichi of Software Research Associates, Tokyo,
     contributed the support for the Sony NEWS machine.

   * Charles LaBrec contributed the support for the Integrated
     Solutions 68020 system.

   * Michael Tiemann of MCC wrote most of the description of the
     National Semiconductor 32000 series cpu.  He also wrote the code
     for inline function integration and for the SPARC cpu and
     Motorola 88000 cpu and part of the Sun FPA support.

   * Jan Stein of the Chalmers Computer Society provided support for
     Genix, as well as part of the 32000 machine description.

   * Randy Smith finished the Sun FPA support.

   * Robert Brown implemented the support for Encore 32000 systems.

   * David Kashtan of SRI adapted GNU CC to the Vomit-Making System.

   * Alex Crain provided changes for the 3b1.

   * Greg Satz and Chris Hanson assisted in making GNU CC work on
     HP-UX for the 9000 series 300.

   * William Schelter did most of the work on the Intel 80386 support.

   * Christopher Smith did the port for Convex machines.

   * Paul Petersen wrote the machine description for the Alliant FX/8.

   * Alain Lichnewsky ported GNU CC to the Mips cpu.

   * Devon Bowen, Dale Wiles and Kevin Zachmann ported GNU CC to the
     Tahoe.

   * Jonathan Stone wrote the machine description for the Pyramid
     computer.


File: gcc.info,  Node: Boycott,  Next: Options,  Prev: Contributors,  Up: Top

Protect Your Freedom--Fight "Look And Feel"
*******************************************

     This section is a political message from the League for
     Programming Freedom to the users of GNU CC.  It is included here
     as an expression of support for the League on the part of the
     Free Software Foundation and Richard Stallman.

   Ashton-Tate, Apple, Lotus and Xerox are trying to create a new
form of legal monopoly: a copyright on a class of user interfaces. 
These monopolies would cause serious problems for users and
developers of computer software and systems.

   Until a few years ago, the law seemed clear: no one could restrict
others from using a user interface; programmers were free to
implement any interface they chose.  Imitating interfaces, sometimes
with changes, was standard practice in the computer field.  The
interfaces we know evolved gradually in this way; for example, the
Macintosh user interface drew ideas from the Xerox interface, which
in turn drew on work done at Stanford and SRI.  1-2-3 imitated
VisiCalc, and dBase imitated a database program from JPL.

   Most computer companies, and nearly all computer users, were happy
with this state of affairs.  The companies that are suing say it does
not offer "enough incentive" to develop their products, but they must
have considered it "enough" when they made their decision to do so. 
It seems they are not satisfied with the opportunity to continue to
compete in the marketplace--not even with a head start.

   If Xerox, Lotus, Apple and Ashton-Tate are permitted to make law
through the courts, the precedent will hobble the software industry:

   * Gratuitous incompatibilities will burden users.  Imagine if each
     car manufacturer had to arrange the pedals in a different order.

   * Software will become and remain more expensive.  Users will be
     "locked in" to proprietary interfaces, for which there is no
     real competition.

   * Large companies have an unfair advantage wherever lawsuits
     become commonplace.  Since they can easily afford to sue, they
     can intimidate small companies with threats even when they don't
     really have a case.

   * User interface improvements will come slower, since incremental
     evolution through creative imitation will no longer be permitted.

   * Even Apple, etc., will find it harder to make improvements if
     they can no longer adapt the good ideas that others introduce,
     for fear of weakening their own legal positions.  Some users
     suggest that this stagnation may already have started.

   * If you use GNU software, you might find it of some concern that
     user interface copyright will make it hard for the Free Software
     Foundation to develop programs compatible with the interfaces
     that you already know.

   To protect our freedom from lawsuits like these, a group of
programmers and users have formed a new grass-roots political
organization, the League for Programming Freedom.

   The purpose of the League is to oppose new monopolistic practices
such as user-interface copyright and software patents; it calls for a
return to the legal policies of the recent past, in which these
practices were not allowed.  The League is not concerned with free
software as an issue, and not affiliated with the Free Software
Foundation.

   The League's membership rolls include John McCarthy, inventor of
Lisp, Marvin Minsky, founder of the Artificial Intelligence lab, Guy L.
Steele, Jr., author of well-known books on Lisp and C, as well as
Richard Stallman, the developer of GNU CC.  Please join and add your
name to the list.  Membership dues in the League are $42 per year for
programmers, managers and professionals; $10.50 for students; $21 for
others.

   The League needs both activist members and members who only pay
their dues.

   To join, or for more information, phone (617) 492-0023 or write to:

     League for Programming Freedom
     1 Kendall Square #143
     P.O. Box 9171
     Cambridge, MA 02139       league@prep.ai.mit.edu

   Here are some suggestions from the League for how you can protect
your freedom to write programs:

   * Don't buy from Xerox, Lotus, Apple or Ashton-Tate.  Buy from
     their competitors or from the defendants they are suing.

   * Don't develop software to work with the systems made by these
     companies.

   * Port your existing software to competing systems, so that you
     encourage users to switch.

   * Write letters to company presidents to let them know their
     conduct is unacceptable.

   * Tell your friends and colleagues about this issue and how it
     threatens to ruin the computer industry.

   * Above all, don't work for the look-and-feel plaintiffs, and
     don't accept contracts from them.

   * Write to Congress to explain the importance of this issue.

          House Subcommittee on Intellectual Property
          2137 Rayburn Bldg
          Washington, DC 20515
          
          Senate Subcommittee on Patents, Trademarks and Copyrights
          United States Senate
          Washington, DC 20510

   Express your opinion!  You can make a difference.

