This is Info file gcc.info, produced by Makeinfo-1.49 from the input
file gcc.texi.

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

   Copyright (C) 1988, 1989, 1992 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

   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)


   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. It corresponds to GNU CC version 2.3.

* 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".
* Invoking GCC::    Command options supported by `gcc'.
* Installation::    How to configure, compile and install GNU CC.
* 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


                         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.


   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

   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.


  1. 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.

  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 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.

  3. 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.

  4. 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

       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
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     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.

  5. 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.

  6. 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.

  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. You are not responsible for enforcing compliance
     by third parties to this License.

  8. 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.

  9. 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.

 10. 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.

 11. 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



                      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

   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.

     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
     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

   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

   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: 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 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

   * 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.

   * 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

   * Jonathan Stone wrote the machine description for the Pyramid

   * 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

   * 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.

   * 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 of the Swedish Institute of Computer Science
     implemented multiply-by-constant optimization and better long long
     support, and improved leaf function register allocation.

   * Mike Stump implemented the support for Elxsi 64 bit CPU.

File: gcc.info,  Node: Boycott,  Next: Invoking GCC,  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.

   Apple and Lotus 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.  Xerox, too, has tried to make a monopoly for itself on window
systems; their suit against Apple was thrown out on a technicality, but
Xerox has not said anything to indicate it wouldn't try again.

   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 companies like Xerox, Lotus, and Apple 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

   * 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

   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

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

   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 `league@prep.ai.mit.edu'.

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

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

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

   * 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

     (These committees have received lots of mail already; let's give
     them even more.)

   Express your opinion!  You can make a difference.

File: gcc.info,  Node: Invoking GCC,  Next: Installation,  Prev: Boycott,  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.

   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.
* Dialect Options::     Controlling the variant of C language compiled.
* 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.

File: gcc.info,  Node: Option Summary,  Next: Overall Options,  Up: Invoking GCC

Option Summary

   Here is a summary of all the options, grouped by type.  Explanations
are in the following sections.

*Overall Options*
     *Note Options Controlling the Kind of Output: Overall Options.
          -c  -S  -E  -o FILE  -pipe  -v  -x LANGUAGE

*Language Options*
     *Note Options Controlling Dialect: Dialect Options.
          -ansi  -fcond-mismatch  -fno-asm  -fno-builtin
          -fsigned-bitfields  -fsigned-char
          -funsigned-bitfields  -funsigned-char  -fwritable-strings
          -traditional  -traditional-cpp  -trigraphs
          -fall-virtual  -fdollars-in-identifiers  -fenum-int-equiv
          -fno-strict-prototype  -fthis-is-variable

*Warning Options*
     *Note Options to Request or Suppress Warnings: Warning Options.
          -fsyntax-only  -pedantic  -pedantic-errors
          -w  -W  -Wall  -Waggregate-return
          -Wcast-align  -Wcast-qual  -Wcomment  -Wconversion  -Werror
          -Wformat  -Wid-clash-LEN  -Wenum-clash  -Wimplicit  -Wimport
          -Winline -Wmissing-prototypes  -Wnested-externs  -Wparentheses
          -Wpointer-arith  -Wredundant-decls  -Wreturn-type  -Wshadow
          -Wstrict-prototypes  -Wswitch  -Wtraditional  -Wtrigraphs
          -Wuninitialized  -Wunused  -Wwrite-strings  -Wchar-subscripts

*Debugging Options*
     *Note Options for Debugging Your Program or GCC: Debugging Options.
          -a  -dLETTERS  -fpretend-float
          -g  -gLEVEL -ggdb  -gdwarf -gdwarf+
          -gstabs  -gstabs+  -gcoff -gxcoff -gxcoff+
          -p  -pg  -save-temps

*Optimization Options*
     *Note Options that Control Optimization: Optimize Options.
          -fcaller-saves  -fcse-follow-jumps  -fcse-skip-blocks
          -fdelayed-branch   -fexpensive-optimizations  -ffast-math
          -ffloat-store  -fforce-addr  -fforce-mem
          -finline-functions  -fkeep-inline-functions  -fno-defer-pop
          -fno-function-cse  -fno-inline  -fno-peephole  -fomit-frame-pointer
          -frerun-cse-after-loop  -fschedule-insns  -fschedule-insns2
          -fstrength-reduce  -fthread-jumps
          -funroll-all-loops  -funroll-loops
          -felide-constructors  -fmemoize-lookups  -fno-default-inline
          -O  -O2

*Preprocessor Options*
     *Note Options Controlling the Preprocessor: Preprocessor Options.
          -AASSERTION  -C  -dD  -dM  -dN
          -DMACRO[=DEFN]  -E  -H
          -include FILE  -imacros FILE
          -M  -MD  -MM  -MMD  -nostdinc  -P  -trigraphs  -UMACRO

*Assembler Option*
     *Note Passing Options to the Assembler: Assembler Options.

*Linker Options*
     *Note Options for Linking: Link Options.
          -lLIBRARY  -nostdlib
          -static  -shared  -symbolic
          -Xlinker OPTION
          -u SYMBOL

*Directory Options*
     *Note Options for Directory Search: Directory Options.
          -BPREFIX  -IDIR  -I-  -LDIR

*Target Options*
     *Note Target Machine and Compiler Version: Target Options.
          -b MACHINE  -V VERSION

*Machine Dependent Options*
     *Note Hardware Models and Configurations: Submodel Options.
          *M680x0 Options*
          -m68000 -m68020 -m68020-40 -m68030 -m68040 -m68881 -mbitfield
          -mc68000 -mc68020 -mfpa -mnobitfield -mrtd -mshort -msoft-float
          *VAX Options*
          -mg -mgnu -munix
          *SPARC Options*
          -mforce-align  -mno-epilogue
          *Convex Options*
          -margcount -mc1 -mc2 -mnoargcount
          *AMD29K Options*
          -m29000 -m29050 -mbw -mdw -mkernel-registers -mlarge
          -mnbw -mnodw -msmall -mstack-check -muser-registers
          *M88K Options*
          -m88000 -m88100 -m88110 -mbig-pic -mcheck-zero-division
          -mhandle-large-shift -midentify-revision
          -mno-check-zero-division -mno-ocs-debug-info
          -mno-ocs-frame-position -mno-optimize-arg-area -mno-underscores
          -mocs-debug-info -mocs-frame-position -moptimize-arg-area
          -mshort-data-NUM -msvr3 -msvr4 -mtrap-large-shift
          -muse-div-instruction -mversion-03.00 -mwarn-passed-structs
          *RS/6000 Options*
          -mfp-in-toc -mno-fop-in-toc
          *RT Options*
          -mcall-lib-mul -mfp-arg-in-fpregs -mfp-arg-in-gregs
          -mfull-fp-blocks -mhc-struct-return -min-line-mul
          -mminimum-fp-blocks -mnohc-struct-return
          *MIPS Options*
          -mcpu=CPU TYPE -mips2 -mips3 -mint64 -mlong64 -mlonglong128
          -mmips-as -mgas -mrnames -mno-rnames -mgpopt -mno-gpopt -mstats
          -mno-stats -mmemcpy -mno-memcpy -mno-mips-tfile -mmips-tfile
          -msoft-float -mhard-float -mabicalls -mno-abicalls -mhalf-pic
          -mno-half-pic -G NUM -nocpp
          *i386 Options*
          -m486 -mno-486 -msoft-float -msvr3-shlib -mieee-fp
          *HPPA Options*
          *Intel 960 Options*
          -mCPU TYPE
          -mnumerics -msoft-float
          -mcode-align -mno-code-align
          -mleaf-procedures -mno-leaf-procedures
          -mtail-call -mno-tail-call
          -mcomplex-addr -mno-complex-addr
          -mclean-linkage -mno-clean-linkage
          -mic-compat -mic2.0-compat -mic3.0-compat
          -masm-compat -mintel-asm
          -mstrict-align -mno-strict-align
          -mold-align -mno-old-align
          *DEC Alpha Options*
          -mfp-regs -mno-fp-regs -mno-soft-float -msoft-float
          *System V Options*
          -G  -Qy  -Qn  -YP,PATHS  -Ym,DIR

*Code Generation Options*
     *Note Options for Code Generation Conventions: Code Gen Options.
          -fcall-saved-REG  -fcall-used-REG  -ffixed-REG
          -finhibit-size-directive  -fnonnull-objects  -fno-common
          -fno-ident  -fno-gnu-linker  -fpcc-struct-return  -fpic  -fPIC
          -fshared-data  -fshort-enums  -fshort-double  -fvolatile

* Menu:

* Overall Options::     Controlling the kind of output:
                        an executable, object files, assembler files,
                        or preprocessed source.
* Dialect Options::     Controlling the variant of C language compiled.
* 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.

File: gcc.info,  Node: Overall Options,  Next: Dialect Options,  Prev: Option Summary,  Up: Invoking GCC

Options Controlling the Kind of Output

   Compilation can involve up to four stages: preprocessing, compilation
proper, assembly and linking, always in that order.  The first three
stages apply to an individual source file, and end by producing an
object file; linking combines all the object files (those newly
compiled, and those specified as input) into an executable file.

   For any given input file, the file name suffix determines what kind
of compilation is done:

     C source code which must be preprocessed.

     C source code which should not be preprocessed.

     C++ source code which should not be preprocessed.

     Objective-C source code.  Note that you must link with the library
     `libobjc.a' to make an Objective-C program work.

     C header file (not to be compiled or linked).

     C++ source code which must be preprocessed.

     Assembler code.

     Assembler code which must be preprocessed.

     An object file to be fed straight into linking. Any file name with
     no recognized suffix is treated this way.

   You can specify the input language explicitly with the `-x' option:

     Specify explicitly the LANGUAGE for the following input files
     (rather than choosing a default based on the file name suffix).
     This option applies to all following input files until the next
     `-x' option.  Possible values of LANGUAGE are `c', `objective-c',
     `c-header', `c++', `cpp-output', `assembler', and

`-x none'
     Turn off any specification of a language, so that subsequent files
     are handled according to their file name suffixes (as they are if
     `-x' has not been used at all).

   If you only want some of the stages of compilation, you can use `-x'
(or filename suffixes) to tell `gcc' where to start, and one of the
options `-c', `-S', or `-E' to say where `gcc' is to stop.  Note that
some combinations (for example, `-x cpp-output -E' instruct `gcc' to do
nothing at all.

     Compile or assemble the source files, but do not link.  The linking
     stage simply is not done.  The ultimate output is in the form of an
     object file for each source file.

     By default, the object file name for a source file is made by
     replacing the suffix `.c', `.i', `.s', etc., with `.o'.

     Unrecognized input files, not requiring compilation or assembly,
     are ignored.

     Stop after the stage of compilation proper; do not assemble.  The
     output is in the form of an assembler code file for each
     non-assembler input file specified.

     By default, the assembler file name for a source file is made by
     replacing the suffix `.c', `.i', etc., with `.s'.

     Input files that don't require compilation are ignored.

     Stop after the preprocessing stage; do not run the compiler
     proper.  The output is in the form of preprocessed source code,
     which is sent to the standard output.

     Input files which don't require preprocessing are ignored.

`-o FILE'
     Place output in file FILE.  This applies regardless to whatever
     sort of output is being produced, whether it be an executable file,
     an object file, an assembler file or preprocessed C code.

     Since only one output file can be specified, it does not make
     sense to use `-o' when compiling more than one input file, unless
     you are producing an executable file as output.

     If `-o' is not specified, the default is to put an executable file
     in `a.out', the object file for `SOURCE.SUFFIX' in `SOURCE.o', its
     assembler file in `SOURCE.s', and all preprocessed C source on
     standard output.

     Print (on standard error output) the commands executed to run the
     stages of compilation.  Also print the version number of the
     compiler driver program and of the preprocessor and the compiler

     Use pipes rather than temporary files for communication between the
     various stages of compilation.  This fails to work on some systems
     where the assembler is unable to read from a pipe; but the GNU
     assembler has no trouble.