This is gcj.info, produced by makeinfo version 4.0 from gcj.texi.

INFO-DIR-SECTION Programming
START-INFO-DIR-ENTRY
* Gcj: (gcj).               Ahead-of-time compiler for the Java language
END-INFO-DIR-ENTRY

INFO-DIR-SECTION Individual utilities
START-INFO-DIR-ENTRY
* gcjh: (gcj)Invoking gcjh.
                            Generate header files from Java class files
* jv-scan: (gcj)Invoking jv-scan.
                            Print information about Java source files
* jcf-dump: (gcj)Invoking jcf-dump.
                            Print information about Java class files
* gij: (gcj)Invoking gij.   GNU interpreter for Java bytecode
END-INFO-DIR-ENTRY

   Copyright (C) 2001 Free Software Foundation, Inc.

   Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with the
Invariant Sections being "GNU General Public License", the Front-Cover
texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below).  A copy of the license is included in the section entitled
"GNU Free Documentation License".

   (a) The FSF's Front-Cover Text is:

   A GNU Manual

   (b) The FSF's Back-Cover Text is:

   You have freedom to copy and modify this GNU Manual, like GNU
software.  Copies published by the Free Software Foundation raise
funds for GNU development.


File: gcj.info,  Node: Top,  Next: Copying,  Up: (dir)

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

   This manual describes how to use `gcj', the GNU compiler for the
Java programming language.  `gcj' can generate both `.class' files and
object files, and it can read both Java source code and `.class' files.

* Menu:

* Copying::		The GNU General Public License
* GNU Free Documentation License::
			How you can share and copy this manual
* Invoking gcj::	Compiler options supported by `gcj'
* Compatibility::	Compatibility between gcj and other tools for Java
* Invoking gcjh::       Generate header files from class files
* Invoking jv-scan::    Print information about source files
* Invoking jcf-dump::   Print information about class files
* Invoking gij::	Interpreting Java bytecodes
* Resources::		Where to look for more information


File: gcj.info,  Node: Copying,  Next: GNU Free Documentation License,  Prev: Top,  Up: Top

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

                         Version 2, June 1991

     Copyright (C) 1989, 1991 Free Software Foundation, Inc.
     59 Temple Place - Suite 330, Boston, MA 02111-1307, 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) YEAR  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., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, 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) YEAR 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: gcj.info,  Node: GNU Free Documentation License,  Next: Invoking gcj,  Prev: Copying,  Up: Top

GNU Free Documentation License
******************************

                        Version 1.1, March 2000

     Copyright (C) 2000 Free Software Foundation, Inc.
     59 Temple Place, Suite 330, Boston, MA  02111-1307, USA
     
     Everyone is permitted to copy and distribute verbatim copies
     of this license document, but changing it is not allowed.

  0. PREAMBLE

     The purpose of this License is to make a manual, textbook, or other
     written document "free" in the sense of freedom: to assure everyone
     the effective freedom to copy and redistribute it, with or without
     modifying it, either commercially or noncommercially.  Secondarily,
     this License preserves for the author and publisher a way to get
     credit for their work, while not being considered responsible for
     modifications made by others.

     This License is a kind of "copyleft", which means that derivative
     works of the document must themselves be free in the same sense.
     It complements the GNU General Public License, which is a copyleft
     license designed for free software.

     We have designed this License in order to use it for manuals for
     free software, because free software needs free documentation: a
     free program should come with manuals providing the same freedoms
     that the software does.  But this License is not limited to
     software manuals; it can be used for any textual work, regardless
     of subject matter or whether it is published as a printed book.
     We recommend this License principally for works whose purpose is
     instruction or reference.

  1. APPLICABILITY AND DEFINITIONS

     This License applies to any manual or other work that contains a
     notice placed by the copyright holder saying it can be distributed
     under the terms of this License.  The "Document", below, refers to
     any such manual or work.  Any member of the public is a licensee,
     and is addressed as "you".

     A "Modified Version" of the Document means any work containing the
     Document or a portion of it, either copied verbatim, or with
     modifications and/or translated into another language.

     A "Secondary Section" is a named appendix or a front-matter
     section of the Document that deals exclusively with the
     relationship of the publishers or authors of the Document to the
     Document's overall subject (or to related matters) and contains
     nothing that could fall directly within that overall subject.
     (For example, if the Document is in part a textbook of
     mathematics, a Secondary Section may not explain any mathematics.)
     The relationship could be a matter of historical connection with
     the subject or with related matters, or of legal, commercial,
     philosophical, ethical or political position regarding them.

     The "Invariant Sections" are certain Secondary Sections whose
     titles are designated, as being those of Invariant Sections, in
     the notice that says that the Document is released under this
     License.

     The "Cover Texts" are certain short passages of text that are
     listed, as Front-Cover Texts or Back-Cover Texts, in the notice
     that says that the Document is released under this License.

     A "Transparent" copy of the Document means a machine-readable copy,
     represented in a format whose specification is available to the
     general public, whose contents can be viewed and edited directly
     and straightforwardly with generic text editors or (for images
     composed of pixels) generic paint programs or (for drawings) some
     widely available drawing editor, and that is suitable for input to
     text formatters or for automatic translation to a variety of
     formats suitable for input to text formatters.  A copy made in an
     otherwise Transparent file format whose markup has been designed
     to thwart or discourage subsequent modification by readers is not
     Transparent.  A copy that is not "Transparent" is called "Opaque".

     Examples of suitable formats for Transparent copies include plain
     ASCII without markup, Texinfo input format, LaTeX input format,
     SGML or XML using a publicly available DTD, and
     standard-conforming simple HTML designed for human modification.
     Opaque formats include PostScript, PDF, proprietary formats that
     can be read and edited only by proprietary word processors, SGML
     or XML for which the DTD and/or processing tools are not generally
     available, and the machine-generated HTML produced by some word
     processors for output purposes only.

     The "Title Page" means, for a printed book, the title page itself,
     plus such following pages as are needed to hold, legibly, the
     material this License requires to appear in the title page.  For
     works in formats which do not have any title page as such, "Title
     Page" means the text near the most prominent appearance of the
     work's title, preceding the beginning of the body of the text.

  2. VERBATIM COPYING

     You may copy and distribute the Document in any medium, either
     commercially or noncommercially, provided that this License, the
     copyright notices, and the license notice saying this License
     applies to the Document are reproduced in all copies, and that you
     add no other conditions whatsoever to those of this License.  You
     may not use technical measures to obstruct or control the reading
     or further copying of the copies you make or distribute.  However,
     you may accept compensation in exchange for copies.  If you
     distribute a large enough number of copies you must also follow
     the conditions in section 3.

     You may also lend copies, under the same conditions stated above,
     and you may publicly display copies.

  3. COPYING IN QUANTITY

     If you publish printed copies of the Document numbering more than
     100, and the Document's license notice requires Cover Texts, you
     must enclose the copies in covers that carry, clearly and legibly,
     all these Cover Texts: Front-Cover Texts on the front cover, and
     Back-Cover Texts on the back cover.  Both covers must also clearly
     and legibly identify you as the publisher of these copies.  The
     front cover must present the full title with all words of the
     title equally prominent and visible.  You may add other material
     on the covers in addition.  Copying with changes limited to the
     covers, as long as they preserve the title of the Document and
     satisfy these conditions, can be treated as verbatim copying in
     other respects.

     If the required texts for either cover are too voluminous to fit
     legibly, you should put the first ones listed (as many as fit
     reasonably) on the actual cover, and continue the rest onto
     adjacent pages.

     If you publish or distribute Opaque copies of the Document
     numbering more than 100, you must either include a
     machine-readable Transparent copy along with each Opaque copy, or
     state in or with each Opaque copy a publicly-accessible
     computer-network location containing a complete Transparent copy
     of the Document, free of added material, which the general
     network-using public has access to download anonymously at no
     charge using public-standard network protocols.  If you use the
     latter option, you must take reasonably prudent steps, when you
     begin distribution of Opaque copies in quantity, to ensure that
     this Transparent copy will remain thus accessible at the stated
     location until at least one year after the last time you
     distribute an Opaque copy (directly or through your agents or
     retailers) of that edition to the public.

     It is requested, but not required, that you contact the authors of
     the Document well before redistributing any large number of
     copies, to give them a chance to provide you with an updated
     version of the Document.

  4. MODIFICATIONS

     You may copy and distribute a Modified Version of the Document
     under the conditions of sections 2 and 3 above, provided that you
     release the Modified Version under precisely this License, with
     the Modified Version filling the role of the Document, thus
     licensing distribution and modification of the Modified Version to
     whoever possesses a copy of it.  In addition, you must do these
     things in the Modified Version:

       A. Use in the Title Page (and on the covers, if any) a title
          distinct from that of the Document, and from those of
          previous versions (which should, if there were any, be listed
          in the History section of the Document).  You may use the
          same title as a previous version if the original publisher of
          that version gives permission.

       B. List on the Title Page, as authors, one or more persons or
          entities responsible for authorship of the modifications in
          the Modified Version, together with at least five of the
          principal authors of the Document (all of its principal
          authors, if it has less than five).

       C. State on the Title page the name of the publisher of the
          Modified Version, as the publisher.

       D. Preserve all the copyright notices of the Document.

       E. Add an appropriate copyright notice for your modifications
          adjacent to the other copyright notices.

       F. Include, immediately after the copyright notices, a license
          notice giving the public permission to use the Modified
          Version under the terms of this License, in the form shown in
          the Addendum below.

       G. Preserve in that license notice the full lists of Invariant
          Sections and required Cover Texts given in the Document's
          license notice.

       H. Include an unaltered copy of this License.

       I. Preserve the section entitled "History", and its title, and
          add to it an item stating at least the title, year, new
          authors, and publisher of the Modified Version as given on
          the Title Page.  If there is no section entitled "History" in
          the Document, create one stating the title, year, authors,
          and publisher of the Document as given on its Title Page,
          then add an item describing the Modified Version as stated in
          the previous sentence.

       J. Preserve the network location, if any, given in the Document
          for public access to a Transparent copy of the Document, and
          likewise the network locations given in the Document for
          previous versions it was based on.  These may be placed in
          the "History" section.  You may omit a network location for a
          work that was published at least four years before the
          Document itself, or if the original publisher of the version
          it refers to gives permission.

       K. In any section entitled "Acknowledgments" or "Dedications",
          preserve the section's title, and preserve in the section all
          the substance and tone of each of the contributor
          acknowledgments and/or dedications given therein.

       L. Preserve all the Invariant Sections of the Document,
          unaltered in their text and in their titles.  Section numbers
          or the equivalent are not considered part of the section
          titles.

       M. Delete any section entitled "Endorsements".  Such a section
          may not be included in the Modified Version.

       N. Do not retitle any existing section as "Endorsements" or to
          conflict in title with any Invariant Section.

     If the Modified Version includes new front-matter sections or
     appendices that qualify as Secondary Sections and contain no
     material copied from the Document, you may at your option
     designate some or all of these sections as invariant.  To do this,
     add their titles to the list of Invariant Sections in the Modified
     Version's license notice.  These titles must be distinct from any
     other section titles.

     You may add a section entitled "Endorsements", provided it contains
     nothing but endorsements of your Modified Version by various
     parties--for example, statements of peer review or that the text
     has been approved by an organization as the authoritative
     definition of a standard.

     You may add a passage of up to five words as a Front-Cover Text,
     and a passage of up to 25 words as a Back-Cover Text, to the end
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File: gcj.info,  Node: Invoking gcj,  Next: Compatibility,  Prev: GNU Free Documentation License,  Up: Top

Invoking gcj
************

   As `gcj' is just another front end to `gcc', it supports many of the
same options as gcc.  *Note Option Summary: (gcc)Option Summary.  This
manual only documents the options specific to `gcj'.

* Menu:

* Input and output files::
* Input Options::		How gcj finds files
* Encodings::                   Options controlling source file encoding
* Warnings::			Options controlling warnings specific to gcj
* Code Generation::		Options controlling the output of gcj
* Configure-time Options::	Options you won't use


File: gcj.info,  Node: Input and output files,  Next: Input Options,  Up: Invoking gcj

Input and output files
======================

   A `gcj' command is like a `gcc' command, in that it consists of a
number of options and file names.  The following kinds of input file
names are supported:

`FILE.java'
     Java source files.

`FILE.class'
     Java bytecode files.

`FILE.zip'
`FILE.jar'
     An archive containing one or more `.class' files, all of which are
     compiled.  The archive may be compressed.

`@FILE'
     A file containing a whitespace-separated list of input file names.
     (Currently, these must all be `.java' source files, but that may
     change.)  Each named file is compiled, just as if it had been on
     the command line.

`LIBRARY.a'
`LIBRARY.so'
`-lLIBNAME'
     Libraries to use when linking.  See the `gcc' manual.

   You can specify more than one input file on the `gcj' command line,
in which case they will all be compiled.  If you specify a `-o FILENAME'
option, all the input files will be compiled together, producing a
single output file, named FILENAME.  This is allowed even when using
`-S' or `-c', but not when using `-C'.  (This is an extension beyond
the what plain `gcc' allows.)  (If more than one input file is
specified, all must currently be `.java' files, though we hope to fix
this.)


File: gcj.info,  Node: Input Options,  Next: Encodings,  Prev: Input and output files,  Up: Invoking gcj

Input Options
=============

   `gcj' has options to control where it looks to find files it needs.
For instance, `gcj' might need to load a class that is referenced by
the file it has been asked to compile.  Like other compilers for the
Java language, `gcj' has a notion of a "class path".  There are several
options and environment variables which can be used to manipulate the
class path.  When `gcj' looks for a given class, it searches the class
path looking for matching `.class' or `.java' file.  `gcj' comes with a
built-in class path which points at the installed `libgcj.jar', a file
which contains all the standard classes.

   In the below, a directory or path component can refer either to an
actual directory on the filesystem, or to a `.zip' or `.jar' file,
which `gcj' will search as if it is a directory.

`-IDIR'
     All directories specified by `-I' are kept in order and prepended
     to the class path constructed from all the other options.  Unless
     compatibility with tools like `javac' is imported, we recommend
     always using `-I' instead of the other options for manipulating the
     class path.

`--classpath=PATH'
     This sets the class path to PATH, a colon-separated list of paths
     (on Windows-based systems, a semicolon-separate list of paths).

`--CLASSPATH=PATH'
     This sets the class path to PATH, a colon-separated list of paths
     (on Windows-based systems, a semicolon-separate list of paths).
     This differs from the `--classpath' option in that it also
     suppresses the built-in system path.

`CLASSPATH'
     This is an environment variable which holds a list of paths.

   The final class path is constructed like so:

   * First come all directories specified via `-I'.

   * If `--classpath' is specified, its value is appended and processing
     stops.  That is, `--classpath' suppresses all the options mentioned
     later in this list.

   * If `--CLASSPATH' is specified, its value is appended and the
     `CLASSPATH' environment variable is suppressed.

   * If the `CLASSPATH' environment variable is specified (and was not
     suppressed by `--CLASSPATH'), then its value is appended.

   * Finally, the built-in system directory, `libgcj.jar', is appended.

   The classfile built by `gcj' for the class `java.lang.Object' (and
placed in `libgcj.jar') contains a special zero length attribute
`gnu.gcj.gcj-compiled'. The compiler looks for this attribute when
loading `java.lang.Object' and will report an error if it isn't found,
unless it compiles to bytecode (the option
`-fforce-classes-archive-check' can be used to overide this behavior in
this particular case.)

`-fforce-classes-archive-check'
     This forces the compiler to always check for the special zero
     length attribute `gnu.gcj.gcj-compiled' in `java.lang.Object' and
     issue an error if it isn't found.


File: gcj.info,  Node: Encodings,  Next: Warnings,  Prev: Input Options,  Up: Invoking gcj

Encodings
=========

   The Java programming language uses Unicode throughout.  In an effort
to integrate well with other locales, `gcj' allows `.java' files to be
written using almost any encoding.  `gcj' knows how to convert these
encodings into its internal encoding at compile time.

   You can use the `--encoding=NAME' option to specify an encoding (of
a particular character set) to use for source files.  If this is not
specified, the default encoding comes from your current locale.  If
your host system has insufficient locale support, then `gcj' assumes
the default encoding to be the `UTF-8' encoding of Unicode.

   To implement `--encoding', `gcj' simply uses the host platform's
`iconv' conversion routine.  This means that in practice `gcj' is
limited by the capabilities of the host platform.

   The names allowed for the argument `--encoding' vary from platform
to platform (since they are not standardized anywhere).  However, `gcj'
implements the encoding named `UTF-8' internally, so if you choose to
use this for your source files you can be assured that it will work on
every host.


File: gcj.info,  Node: Warnings,  Next: Code Generation,  Prev: Encodings,  Up: Invoking gcj

Warnings
========

   `gcj' implements several warnings.  As with other generic `gcc'
warnings, if an option of the form `-Wfoo' enables a warning, then
`-Wno-foo' will disable it.  Here we've chosen to document the form of
the warning which will have an effect - the default being the opposite
of what is listed.

`-Wredundant-modifiers'
     With this flag, `gcj' will warn about redundant modifiers.  For
     instance, it will warn if an interface method is declared `public'.

`-Wextraneous-semicolon'
     This causes `gcj' to warn about empty statements.  Empty statements
     have been deprecated.

`-Wno-out-of-date'
     This option will cause `gcj' not to warn when a source file is
     newer than its matching class file.  By default `gcj' will warn
     about this.

`-Wunused'
     This is the same as `gcc''s `-Wunused'.

`-Wall'
     This is the same as `-Wredundant-modifiers -Wextraneous-semicolon
     -Wunused'.


File: gcj.info,  Node: Code Generation,  Next: Configure-time Options,  Prev: Warnings,  Up: Invoking gcj

Code Generation
===============

   In addition to the many `gcc' options controlling code generation,
`gcj' has several options specific to itself.

`--main=CLASSNAME'
     This option is used when linking to specify the name of the class
     whose `main' method should be invoked when the resulting
     executable is run.  (1)

`-DNAME[=VALUE]'
     This option can only be used with `--main'.  It defines a system
     property named NAME with value VALUE.  If VALUE is not specified
     then it defaults to the empty string.  These system properties are
     initialized at the program's startup and can be retrieved at
     runtime using the `java.lang.System.getProperty' method.

`-C'
     This option is used to tell `gcj' to generate bytecode (`.class'
     files) rather than object code.

`-d DIRECTORY'
     When used with `-C', this causes all generated `.class' files to
     be put in the appropriate subdirectory of DIRECTORY.  By default
     they will be put in subdirectories of the current working
     directory.

`-fno-bounds-check'
     By default, `gcj' generates code which checks the bounds of all
     array indexing operations.  With this option, these checks are
     omitted.  Note that this can result in unpredictable behavior if
     the code in question actually does violate array bounds
     constraints.

`-fjni'
     With `gcj' there are two options for writing native methods: CNI
     and JNI.  By default `gcj' assumes you are using CNI.  If you are
     compiling a class with native methods, and these methods are
     implemented using JNI, then you must use `-fjni'.  This option
     causes `gcj' to generate stubs which will invoke the underlying JNI
     methods.

   ---------- Footnotes ----------

   (1) The linker by default looks for a global function named `main'.
Since Java does not have global functions, and a collection of Java
classes may have more than one class with a `main' method, you need to
let the linker know which of those `main' methods it should invoke when
starting the application.


File: gcj.info,  Node: Configure-time Options,  Prev: Code Generation,  Up: Invoking gcj

Configure-time Options
======================

   Some `gcj' code generations options affect the resulting ABI, and so
can only be meaningfully given when `libgcj', the runtime package, is
configured.  `libgcj' puts the appropriate options from this group into
a `spec' file which is read by `gcj'.  These options are listed here
for completeness; if you are using `libgcj' then you won't want to
touch these options.

`-fuse-boehm-gc'
     This enables the use of the Boehm GC bitmap marking code.  In
     particular this causes `gcj' to put an object marking descriptor
     into each vtable.

`-fhash-synchronization'
     By default, synchronization data (the data used for `synchronize',
     `wait', and `notify') is pointed to by a word in each object.
     With this option `gcj' assumes that this information is stored in a
     hash table and not in the object itself.

`-fuse-divide-subroutine'
     On some systems, a library routine is called to perform integer
     division.  This is required to get exception handling correct when
     dividing by zero.


File: gcj.info,  Node: Compatibility,  Next: Invoking gcjh,  Prev: Invoking gcj,  Up: Top

Compatibility with the Java Platform
************************************

   As we believe it is important that the Java platform not be
fragmented, `gcj' and `libgcj' try to conform to the relevant Java
specifications.  However, limited manpower and incomplete and unclear
documentation work against us.  So, there are caveats to using `gcj'.

   This list of compatibility issues is by no means complete.

   * `gcj' implements the JDK 1.1 language.  It supports inner classes,
     though these are known to still be buggy.  It does not yet support
     the Java 2 `strictfp' keyword (it recognizes the keyword but
     ignores it).

   * `libgcj' is largely compatible with the JDK 1.2 libraries.
     However, `libgcj' is missing many packages, most notably
     `java.awt'.  There are also individual missing classes and methods.
     We currently do not have a list showing differences between
     `libgcj' and the Java 2 platform.

   * Sometimes the `libgcj' implementation of a method or class differs
     from the JDK implementation.  This is not always a bug.  Still, if
     it affects you, it probably makes sense to report it so that we
     can discuss the appropriate response.


File: gcj.info,  Node: Invoking gcjh,  Next: Invoking jv-scan,  Prev: Compatibility,  Up: Top

Invoking gcjh
*************

   The `gcjh' program is used to generate header files from class
files.  It can generate both CNI and JNI header files, as well as stub
implementation files which can be used as a basis for implementing the
required native methods.

`-stubs'
     This causes `gcjh' to generate stub files instead of header files.
     By default the stub file will be named after the class, with a
     suffix of `.cc'.  In JNI mode, the default output file will have
     the suffix `.c'.

`-jni'
     This tells `gcjh' to generate a JNI header or stub.  By default,
     CNI headers are generated.

`-add TEXT'
     Inserts TEXT into the class body.  This is ignored in JNI mode.

`-append TEXT'
     Inserts TEXT into the header file after the class declaration.
     This is ignored in JNI mode.

`-friend TEXT'
     Inserts TEXT into the class as a `friend' declaration.  This is
     ignored in JNI mode.

`-prepend TEXT'
     Inserts TEXT into the header file before the class declaration.
     This is ignored in JNI mode.

`--classpath=PATH'
`--CLASSPATH=PATH'
`-IDIRECTORY'
`-d DIRECTORY'
`-o FILE'
     These options are all identical to the corresponding `gcj' options.

`-o FILE'
     Sets the output file name.  This cannot be used if there is more
     than one class on the command line.

`-td DIRECTORY'
     Sets the name of the directory to use for temporary files.

`--help'
     Print help about `gcjh' and exit.  No further processing is done.

`--version'
     Print version information for `gcjh' and exit.  No further
     processing is done.

   All remaining options are considered to be names of classes.


File: gcj.info,  Node: Invoking jv-scan,  Next: Invoking jcf-dump,  Prev: Invoking gcjh,  Up: Top

Invoking jv-scan
****************

   The `jv-scan' program can be used to print information about a Java
source file (`.java' file).

`--complexity'
     This prints a complexity measure, related to cyclomatic
     complexity, for each input file.

`--encoding=NAME'
     This works like the corresponding `gcj' option.

`--print-main'
     This prints the name of the class in this file containing a `main'
     method.

`--list-class'
     This lists the names of all classes defined in the input files.

`--list-filename'
     If `--list-class' is given, this option causes `jv-scan' to also
     print the name of the file in which each class was found.

`-o FILE'
     Print output to the named file.


File: gcj.info,  Node: Invoking jcf-dump,  Next: Invoking gij,  Prev: Invoking jv-scan,  Up: Top

Invoking jcf-dump
*****************

   This is a class file examiner, similar to `javap'.  It will print
information about a number of classes, which are specifed by class name
or file name.

`-c'
     Disassemble method bodies.  By default method bodies are not
     printed.

`--javap'
     Generate output in `javap' format.  The implementation of this
     feature is very incomplete.

`--classpath=PATH'
`--CLASSPATH=PATH'
`-IDIRECTORY'
`-o FILE'
     These options as the same as the corresponding `gcj' options.


File: gcj.info,  Node: Invoking gij,  Next: Resources,  Prev: Invoking jcf-dump,  Up: Top

Invoking gij
************

   `gij' is a Java bytecode interpreter included with `libgcj'.  `gij'
is not available on every platform; porting it requires a small amount
of assembly programming which has not been done for all the targets
supported by `gcj'.

   The primary argument to `gij' is the name of a class or, with
`-jar', a jar file.  Options before this argument are interpreted by
`gij'; remaining options are passed to the interpreted program.

   If a class name is specified and this class does not have a `main'
method with the appropriate signature (a `static void' method with a
`String[]' as its sole argument), then `gij' will print an error and
exit.

   If a jar file is specified then `gij' will use information in it to
determine which class' `main' method will be invoked.

   `gij' will invoke the `main' method with all the remaining
command-line options.

   Note that `gij' is not limited to interpreting code.  Because
`libgcj' includes a class loader which can dynamically load shared
objects, it is possible to give `gij' the name of a class which has
been compiled and put into a shared library on the class path.

`-DNAME[=VALUE]'
     This defines a system property named NAME with value VALUE.  If
     VALUE is not specified then it defaults to the empty string.
     These system properties are initialized at the program's startup
     and can be retrieved at runtime using the
     `java.lang.System.getProperty' method.

`-ms=NUMBER'
     This sets the initial heap size

`-mx=NUMBER'
     This sets the maximum heap size.

`-jar'
     This indicates that the name passed to `gij' should be interpreted
     as the name of a jar file, not a class.


File: gcj.info,  Node: Resources,  Prev: Invoking gij,  Up: Top

Resources
*********

   While writing `gcj' and `libgcj' we have, of course, relied heavily
on documentation from Sun Microsystems.  In particular we have used The
Java Language Specification (both first and second editions), the Java
Class Libraries (volumes one and two), and the Java Virtual Machine
Specification.  In addition we've used the online documentation at
`http://java.sun.com/'.

   The current `gcj' home page is `http://gcc.gnu.org/java/'.

   For more information on gcc, see `http://gcc.gnu.org/'.

   Some `libgcj' testing is done using the Mauve test suite.  This is a
free software Java class library test suite which is being written
because the JCK is not free.  See `http://sources.redhat.com/mauve/'
for more information.



Tag Table:
Node: Top1427
Node: Copying2256
Node: GNU Free Documentation License21461
Node: Invoking gcj41346
Node: Input and output files41997
Node: Input Options43344
Node: Encodings46314
Node: Warnings47515
Node: Code Generation48546
Ref: Code Generation-Footnote-150407
Node: Configure-time Options50716
Node: Compatibility51880
Node: Invoking gcjh53172
Node: Invoking jv-scan54917
Node: Invoking jcf-dump55726
Node: Invoking gij56347
Node: Resources58129

End Tag Table
