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This is Info file gcc.info, produced by Makeinfo-1.55 from the input
file gcc.texi.
This file documents the use and the internals of the GNU compiler.
Published by the Free Software Foundation 59 Temple Place - Suite 330
Boston, MA 02111-1307 USA
Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995 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," "Funding for
Free Software," 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," "Funding for Free Software," 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 compiler,
as well as its new features and incompatibilities, and how to report
bugs. It corresponds to GNU CC version 2.7.
* Menu:
* Copying:: GNU General Public License says
how you can copy and share GNU CC.
* Contributors:: People who have contributed to GNU CC.
* Funding:: How to help assure funding for free software.
* Look and Feel:: Protect your freedom--fight "look and feel".
* G++ and GCC:: You can compile C or C++ programs.
* Invoking GCC:: Command options supported by `gcc'.
* Installation:: How to configure, compile and install GNU CC.
* C Extensions:: GNU extensions to the C language family.
* C++ Extensions:: GNU extensions to the C++ language.
* Trouble:: If you have trouble installing GNU CC.
* Bugs:: How, why and where to report bugs.
* Service:: How to find suppliers of support for GNU CC.
* VMS:: Using GNU CC on VMS.
* 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.
* Target Macros:: How to write the machine description C macros.
* Config:: Writing the `xm-MACHINE.h' file.
* Index:: Index of concepts and symbol names.
File: gcc.info, Node: Copying, Next: Contributors, Prev: Top, Up: Top
GNU GENERAL PUBLIC LICENSE
**************************
Version 2, June 1991
Copyright (C) 1989, 1991 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 licenses for most software are designed to take away your
freedom to share and change it. By contrast, the GNU 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. This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it. (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.) You can apply it to
your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), 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 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 show them these terms so they know 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.
Finally, any free program is threatened constantly by software
patents. We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary. To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.
The precise terms and conditions for copying, distribution and
modification follow.
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License 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 derivative work under
copyright law: that is to say, a work containing the Program or a
portion of it, either verbatim or with modifications and/or
translated into another language. (Hereinafter, translation is
included without limitation in the term "modification".) Each
licensee is addressed as "you".
Activities other than copying, distribution and modification are
not covered by this License; they are outside its scope. The act
of running the Program is not restricted, and the output from the
Program is covered only if its contents constitute a work based on
the Program (independent of having been made by running the
Program). Whether that is true depends on what the Program does.
1. 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 License and to the absence of any
warranty; and give any other recipients of the Program a copy of
this License along with the Program.
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.
2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
a. You must cause the modified files to carry prominent notices
stating that you changed the files and the date of any change.
b. You must cause any work that you distribute or publish, that
in whole or in part contains or is derived from the Program
or any part thereof, to be licensed as a whole at no charge
to all third parties under the terms of this License.
c. If the modified program normally reads commands interactively
when run, you must cause it, when started running for such
interactive use in the most ordinary 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 License. (Exception: if the Program
itself is interactive but does not normally print such an
announcement, your work based on the Program is not required
to print an announcement.)
These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the
Program, and can be reasonably considered independent and separate
works in themselves, then this License, and its terms, do not
apply to those sections when you distribute them as separate
works. But when you distribute the same sections as part of a
whole which is a work based on the Program, the distribution of
the whole must be on the terms of this License, whose permissions
for other licensees extend to the entire whole, and thus to each
and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or
contest your rights to work written entirely by you; rather, the
intent is to exercise the right to control the distribution of
derivative or collective works based on the Program.
In addition, mere aggregation of another work not based on the
Program with the Program (or with a work based on the Program) on
a volume of a storage or distribution medium does not bring the
other work under the scope of this License.
3. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms
of Sections 1 and 2 above provided that you also do one of the
following:
a. Accompany it with the complete corresponding machine-readable
source code, which must be distributed under the terms of
Sections 1 and 2 above on a medium customarily used for
software interchange; or,
b. Accompany it with a written offer, valid for at least three
years, to give any third party, for a charge no more than your
cost of physically performing source distribution, a complete
machine-readable copy of the corresponding source code, to be
distributed under the terms of Sections 1 and 2 above on a
medium customarily used for software interchange; or,
c. Accompany it with the information you received as to the offer
to distribute corresponding source code. (This alternative is
allowed only for noncommercial distribution and only if you
received the program in object code or executable form with
such an offer, in accord with Subsection b above.)
The source code for a work means the preferred form of the work for
making modifications to it. For an executable work, complete
source code means all the source code for all modules it contains,
plus any associated interface definition files, plus the scripts
used to control compilation and installation of the executable.
However, as a special exception, the source code distributed need
not include anything that is normally distributed (in either
source or binary form) with the major components (compiler,
kernel, and so on) of the operating system on which the executable
runs, unless that component itself accompanies the executable.
If distribution of executable or object code is made by offering
access to copy from a designated place, then offering equivalent
access to copy the source code from the same place counts as
distribution of the source code, even though third parties are not
compelled to copy the source along with the object code.
4. You may not copy, modify, sublicense, or distribute the Program
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense or distribute the Program is
void, and will automatically terminate your rights under this
License. However, parties who have received copies, or rights,
from you under this License will not have their licenses
terminated so long as such parties remain in full compliance.
5. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify
or distribute the Program or its derivative works. These actions
are prohibited by law if you do not accept this License.
Therefore, by modifying or distributing 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 for copying,
distributing or modifying the Program or works based on it.
6. 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. You are not responsible for enforcing compliance
by third parties to this License.
7. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent
issues), conditions are imposed on you (whether by court order,
agreement or otherwise) that contradict the conditions of this
License, they do not excuse you from the conditions of this
License. If you cannot distribute so as to satisfy simultaneously
your obligations under this License and any other pertinent
obligations, then as a consequence you may not distribute the
Program at all. For example, if a patent license would not permit
royalty-free redistribution of the Program by all those who
receive copies directly or indirectly through you, then the only
way you could satisfy both it and this License would be to refrain
entirely from distribution of the Program.
If any portion of this section is held invalid or unenforceable
under any particular circumstance, the balance of the section is
intended to apply and the section as a whole is intended to apply
in other circumstances.
It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of
any such claims; this section has the sole purpose of protecting
the integrity of the free software distribution system, which is
implemented by public license practices. Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
system; it is up to the author/donor to decide if he or she is
willing to distribute software through any other system and a
licensee cannot impose that choice.
This section is intended to make thoroughly clear what is believed
to be a consequence of the rest of this License.
8. If the distribution and/or use of the Program is restricted in
certain countries either by patents or by copyrighted interfaces,
the original copyright holder who places the Program under this
License may add an explicit geographical distribution limitation
excluding those countries, so that distribution is permitted only
in or among countries not thus excluded. In such case, this
License incorporates the limitation as if written in the body of
this License.
9. 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 this 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 this License, you may choose
any version ever published by the Free Software Foundation.
10. 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
11. 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.
12. 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
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 the public, 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 2 of the License, 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 is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program
`Gnomovision' (which makes passes at compilers) written by James Hacker.
SIGNATURE OF TY COON, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating your
program into proprietary programs. If your program is a subroutine
library, you may consider it more useful to permit linking proprietary
applications with the library. If this is what you want to do, use the
GNU Library General Public License instead of this License.
File: gcc.info, Node: Contributors, Next: Funding, 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 program PO written at the University of Arizona 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 Cygnus Support wrote the front end for C++, as
well as the support for inline functions and instruction
scheduling. Also the descriptions of the National Semiconductor
32000 series cpu, the SPARC cpu and part of the Motorola 88000 cpu.
* Gerald Baumgartner added the signature extension to the C++
front-end.
* 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 VMS.
* 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.
* Dario Dariol contributed the four varieties of sample programs
that print a copy of their source.
* 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.
* Gary Miller ported GNU CC to Charles River Data Systems machines.
* Richard Kenner of the New York University Ultracomputer Research
Laboratory wrote the machine descriptions for the AMD 29000, the
DEC Alpha, the IBM RT PC, and the IBM RS/6000 as well as the
support for instruction attributes. He also made changes to
better support RISC processors including changes to common
subexpression elimination, strength reduction, function calling
sequence handling, and condition code support, in addition to
generalizing the code for frame pointer elimination.
* Richard Kenner and Michael Tiemann jointly developed reorg.c, the
delay slot scheduler.
* Mike Meissner and Tom Wood of Data General finished the port to the
Motorola 88000.
* Masanobu Yuhara of Fujitsu Laboratories implemented the machine
description for the Tron architecture (specifically, the Gmicro).
* NeXT, Inc. donated the front end that supports the Objective C
language.
* James van Artsdalen wrote the code that makes efficient use of the
Intel 80387 register stack.
* Mike Meissner at the Open Software Foundation finished the port to
the MIPS cpu, including adding ECOFF debug support, and worked on
the Intel port for the Intel 80386 cpu.
* Ron Guilmette implemented the `protoize' and `unprotoize' tools,
the support for Dwarf symbolic debugging information, and much of
the support for System V Release 4. He has also worked heavily on
the Intel 386 and 860 support.
* Torbjorn Granlund implemented multiply- and divide-by-constant
optimization, improved long long support, and improved leaf
function register allocation.
* Mike Stump implemented the support for Elxsi 64 bit CPU.
* John Wehle added the machine description for the Western Electric
32000 processor used in several 3b series machines (no relation to
the National Semiconductor 32000 processor).
* Holger Teutsch provided the support for the Clipper cpu.
* Kresten Krab Thorup wrote the run time support for the Objective C
language.
* Stephen Moshier contributed the floating point emulator that
assists in cross-compilation and permits support for floating
point numbers wider than 64 bits.
* David Edelsohn contributed the changes to RS/6000 port to make it
support the PowerPC and POWER2 architectures.
* Steve Chamberlain wrote the support for the Hitachi SH processor.
* Peter Schauer wrote the code to allow debugging to work on the
Alpha.
* Oliver M. Kellogg of Deutsche Aerospace contributed the port to the
MIL-STD-1750A.
* Michael K. Gschwind contributed the port to the PDP-11.
File: gcc.info, Node: Funding, Next: Look and Feel, Prev: Contributors, Up: Top
Funding Free Software
*********************
If you want to have more free software a few years from now, it makes
sense for you to help encourage people to contribute funds for its
development. The most effective approach known is to encourage
commercial redistributors to donate.
Users of free software systems can boost the pace of development by
encouraging for-a-fee distributors to donate part of their selling price
to free software developers--the Free Software Foundation, and others.
The way to convince distributors to do this is to demand it and
expect it from them. So when you compare distributors, judge them
partly by how much they give to free software development. Show
distributors they must compete to be the one who gives the most.
To make this approach work, you must insist on numbers that you can
compare, such as, "We will donate ten dollars to the Frobnitz project
for each disk sold." Don't be satisfied with a vague promise, such as
"A portion of the profits are donated," since it doesn't give a basis
for comparison.
Even a precise fraction "of the profits from this disk" is not very
meaningful, since creative accounting and unrelated business decisions
can greatly alter what fraction of the sales price counts as profit.
If the price you pay is $50, ten percent of the profit is probably less
than a dollar; it might be a few cents, or nothing at all.
Some redistributors do development work themselves. This is useful
too; but to keep everyone honest, you need to inquire how much they do,
and what kind. Some kinds of development make much more long-term
difference than others. For example, maintaining a separate version of
a program contributes very little; maintaining the standard version of a
program for the whole community contributes much. Easy new ports
contribute little, since someone else would surely do them; difficult
ports such as adding a new CPU to the GNU C compiler contribute more;
major new features or packages contribute the most.
By establishing the idea that supporting further development is "the
proper thing to do" when distributing free software for a fee, we can
assure a steady flow of resources into making more free software.
Copyright (C) 1994 Free Software Foundation, Inc.
Verbatim copying and redistribution of this section is permitted
without royalty; alteration is not permitted.
File: gcc.info, Node: Look and Feel, Next: G++ and GCC, Prev: Funding, 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. We have included it here because
the issue of interface copyright is important to the GNU project.
Apple and Lotus have tried to create a new form of legal monopoly: a
copyright on a user interface.
An interface is a kind of language--a set of conventions for
communication between two entities, human or machine. Until a few years
ago, the law seemed clear: interfaces were outside the domain of
copyright, so programmers could program freely and implement whatever
interface the users demanded. Imitating de-facto standard interfaces,
sometimes with improvements, was standard practice in the computer
field. These improvements, if accepted by the users, caught on and
became the norm; in this way, much progress took place.
Computer users, and most software developers, were happy with this
state of affairs. However, large companies such as Apple and Lotus
would prefer a different system--one in which they can own interfaces
and thereby rid themselves of all serious competitors. They hope that
interface copyright will give them, in effect, monopolies on major
classes of software.
Other large companies such as IBM and Digital also favor interface
monopolies, for the same reason: if languages become property, they
expect to own many de-facto standard languages. But Apple and Lotus are
the ones who have actually sued. Lotus has won lawsuits against two
small companies, which were thus put out of business. Then they sued
Borland; this case is now before the court of appeals. Apple's lawsuit
against HP and Microsoft is also being decided by an appeals court.
Widespread rumors that Apple had lost the case are untrue; as of July
1994, the final outcome is unknown.
If the monopolists get their way, they will hobble the software
field:
* Gratuitous incompatibilities will burden users. Imagine if each
car manufacturer had to design a different way to start, stop, and
steer a car.
* Users will be "locked in" to whichever interface they learn; then
they will be prisoners of one supplier, who will charge a
monopolistic price.
* Large companies have an unfair advantage wherever lawsuits become
commonplace. Since they can afford to sue, they can intimidate
smaller developers with threats even when they don't really have a
case.
* Interface improvements will come slower, since incremental
evolution through creative partial imitation will no longer occur.
If interface monopolies are accepted, other large companies are
waiting to grab theirs:
* Adobe is expected to claim a monopoly on the interfaces of various
popular application programs, if Borland's appeal against Lotus
fails.
* Open Computing magazine reported a Microsoft vice president as
threatening to sue people who copy the interface of Windows.
Users invest a great deal of time and money in learning to use
computer interfaces. Far more, in fact, than software developers
invest in developing *and even implementing* the interfaces. Whoever
can own an interface, has made its users into captives, and
misappropriated their investment.
To protect our freedom from monopolies like these, a group of
programmers and users have formed a grass-roots political organization,
the League for Programming Freedom.
The purpose of the League is to oppose monopolistic practices such as
interface copyright and software patents. The League calls for a return
to the legal policies of the recent past, in which programmers could
program freely. The League is not concerned with free software as an
issue, and is not affiliated with the Free Software Foundation.
The League's activities include publicizing the issue, as is being
done here, and filing friend-of-the-court briefs on behalf of
defendants sued by monopolists. Recently the League filed a
friend-of-the-court brief for Borland in its appeal against Lotus.
The League's membership rolls include John McCarthy, inventor of
Lisp, Marvin Minsky, founder of the MIT 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.
Activist members are especially important, but members who have no
time to give are also important. Surveys at major ACM conferences have
indicated a vast majority of attendees agree with the League. If just
ten percent of the programmers who agree with the League join the
League, we will probably triumph.
To join, or for more information, phone (617) 243-4091 or write to:
League for Programming Freedom
1 Kendall Square #143
P.O. Box 9171
Cambridge, MA 02139
You can also send electronic mail to `lpf@uunet.uu.net'.
In addition to joining the League, here are some suggestions from the
League for other things you can do to protect your freedom to write
programs:
* Tell your friends and colleagues about this issue and how it
threatens to ruin the computer industry.
* Mention that you are a League member in your `.signature', and
mention the League's email address for inquiries.
* Ask the companies you consider working for or working with to make
statements against software monopolies, and give preference to
those that do.
* When employers ask you to sign contracts giving them copyright or
patent rights, insist on clauses saying they can use these rights
only defensively. Don't rely on "company policy," since that can
change at any time; don't rely on an individual executive's
private word, since that person may be replaced. Get a commitment
just as binding as the commitment they get from you.
* 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
(These committees have received lots of mail already; let's give
them even more.)
Democracy means nothing if you don't use it. Stand up and be
counted!
File: gcc.info, Node: G++ and GCC, Next: Invoking GCC, Prev: Look and Feel, Up: Top
Compile C, C++, or Objective C
******************************
The C, C++, and Objective C versions of the compiler are integrated;
the GNU C compiler can compile programs written in C, C++, or Objective
"GCC" is a common shorthand term for the GNU C compiler. This is
both the most general name for the compiler, and the name used when the
emphasis is on compiling C programs.
When referring to C++ compilation, it is usual to call the compiler
"G++". Since there is only one compiler, it is also accurate to call
it "GCC" no matter what the language context; however, the term "G++"
is more useful when the emphasis is on compiling C++ programs.
We use the name "GNU CC" to refer to the compilation system as a
whole, and more specifically to the language-independent part of the
compiler. For example, we refer to the optimization options as
affecting the behavior of "GNU CC" or sometimes just "the compiler".
Front ends for other languages, such as Ada 9X, Fortran, Modula-3,
and Pascal, are under development. These front-ends, like that for
C++, are built in subdirectories of GNU CC and link to it. The result
is an integrated compiler that can compile programs written in C, C++,
Objective C, or any of the languages for which you have installed front
ends.
In this manual, we only discuss the options for the C, Objective-C,
and C++ compilers and those of the GNU CC core. Consult the
documentation of the other front ends for the options to use when
compiling programs written in other languages.
G++ is a *compiler*, not merely a preprocessor. G++ builds object
code directly from your C++ program source. There is no intermediate C
version of the program. (By contrast, for example, some other
implementations use a program that generates a C program from your C++
source.) Avoiding an intermediate C representation of the program means
that you get better object code, and better debugging information. The
GNU debugger, GDB, works with this information in the object code to
give you comprehensive C++ source-level editing capabilities (*note C
and C++: (gdb.info)C.).
File: gcc.info, Node: Invoking GCC, Next: Installation, Prev: G++ and GCC, Up: Top
GNU CC Command Options
**********************
When you invoke GNU CC, it normally does preprocessing, compilation,
assembly and linking. The "overall options" allow you to stop this
process at an intermediate stage. For example, the `-c' option says
not to run the linker. Then the output consists of object files output
by the assembler.
Other options are passed on to one stage of processing. Some options
control the preprocessor and others the compiler itself. Yet other
options control the assembler and linker; most of these are not
documented here, since you rarely need to use any of them.
Most of the command line options that you can use with GNU CC are
useful for C programs; when an option is only useful with another
language (usually C++), the explanation says so explicitly. If the
description for a particular option does not mention a source language,
you can use that option with all supported languages.
*Note Compiling C++ Programs: Invoking G++, for a summary of special
options for compiling C++ programs.
The `gcc' program accepts options and file names as operands. Many
options have multiletter names; therefore multiple single-letter options
may *not* be grouped: `-dr' is very different from `-d -r'.
You can mix options and other arguments. For the most part, the
order you use doesn't matter. Order does matter when you use several
options of the same kind; for example, if you specify `-L' more than
once, the directories are searched in the order specified.
Many options have long names starting with `-f' or with `-W'--for
example, `-fforce-mem', `-fstrength-reduce', `-Wformat' and so on.
Most of these have both positive and negative forms; the negative form
of `-ffoo' would be `-fno-foo'. This manual documents only one of
these two forms, whichever one is not the default.
* Menu:
* Option Summary:: Brief list of all options, without explanations.
* Overall Options:: Controlling the kind of output:
an executable, object files, assembler files,
or preprocessed source.
* Invoking G++:: Compiling C++ programs.
* C Dialect Options:: Controlling the variant of C language compiled.
* C++ Dialect Options:: Variations on C++.
* Warning Options:: How picky should the compiler be?
* Debugging Options:: Symbol tables, measurements, and debugging dumps.
* Optimize Options:: How much optimization?
* Preprocessor Options:: Controlling header files and macro definitions.
Also, getting dependency information for Make.
* Assembler Options:: Passing options to the assembler.
* Link Options:: Specifying libraries and so on.
* Directory Options:: Where to find header files and libraries.
Where to find the compiler executable files.
* Target Options:: Running a cross-compiler, or an old version of GNU CC.
* Submodel Options:: Specifying minor hardware or convention variations,
such as 68010 vs 68020.
* Code Gen Options:: Specifying conventions for function calls, data layout
and register usage.
* Environment Variables:: Env vars that affect GNU CC.
* Running Protoize:: Automatically adding or removing function prototypes.