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author | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
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committer | upstream source tree <ports@midipix.org> | 2015-03-15 20:14:05 -0400 |
commit | 554fd8c5195424bdbcabf5de30fdc183aba391bd (patch) | |
tree | 976dc5ab7fddf506dadce60ae936f43f58787092 /gcc/doc/gcj.info | |
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Diffstat (limited to 'gcc/doc/gcj.info')
-rw-r--r-- | gcc/doc/gcj.info | 3694 |
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diff --git a/gcc/doc/gcj.info b/gcc/doc/gcj.info new file mode 100644 index 000000000..b4b0ef359 --- /dev/null +++ b/gcc/doc/gcj.info @@ -0,0 +1,3694 @@ +This is doc/gcj.info, produced by makeinfo version 4.13 from +/home/jakub/gcc-4.6.4/gcc-4.6.4/gcc/java/gcj.texi. + +Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010 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 1.3 or +any later version published by the Free Software Foundation; with no +Invariant Sections, 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. + +INFO-DIR-SECTION Software development +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 +* jcf-dump: (gcj)Invoking jcf-dump. + Print information about Java class files +* gij: (gcj)Invoking gij. GNU interpreter for Java bytecode +* gcj-dbtool: (gcj)Invoking gcj-dbtool. + Tool for manipulating class file databases. +* jv-convert: (gcj)Invoking jv-convert. + Convert file from one encoding to another +* grmic: (gcj)Invoking grmic. + Generate stubs for Remote Method Invocation. +* gc-analyze: (gcj)Invoking gc-analyze. + Analyze Garbage Collector (GC) memory dumps. +* aot-compile: (gcj)Invoking aot-compile. + Compile bytecode to native and generate databases. +* rebuild-gcj-db: (gcj)Invoking rebuild-gcj-db. + Merge the per-solib databases made by aot-compile + into one system-wide database. +END-INFO-DIR-ENTRY + + Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010 +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 1.3 or +any later version published by the Free Software Foundation; with no +Invariant Sections, 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 jcf-dump:: Print information about class files +* Invoking gij:: Interpreting Java bytecodes +* Invoking gcj-dbtool:: Tool for manipulating class file databases. +* Invoking jv-convert:: Converting from one encoding to another +* Invoking grmic:: Generate stubs for Remote Method Invocation. +* Invoking gc-analyze:: Analyze Garbage Collector (GC) memory dumps. +* Invoking aot-compile:: Compile bytecode to native and generate databases. +* Invoking rebuild-gcj-db:: Merge the per-solib databases made by aot-compile + into one system-wide database. +* About CNI:: Description of the Compiled Native Interface +* System properties:: Modifying runtime behavior of the libgcj library +* Resources:: Where to look for more information +* Index:: Index. + + +File: gcj.info, Node: Copying, Next: GNU Free Documentation License, Prev: Top, Up: Top + +GNU General Public License +************************** + + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. `http://fsf.org/' + + Everyone is permitted to copy and distribute verbatim copies of this + license document, but changing it is not allowed. + +Preamble +======== + +The GNU General Public License is a free, copyleft license for software +and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. 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Disclaimer of Warranty. + + 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. + + 16. Limitation of Liability. + + IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN + WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES + AND/OR CONVEYS 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. + + 17. Interpretation of Sections 15 and 16. + + If the disclaimer of warranty and limitation of liability provided + above cannot be given local legal effect according to their terms, + reviewing courts shall apply local law that most closely + approximates an absolute waiver of all civil liability in + connection with the Program, unless a warranty or assumption of + liability accompanies a copy of the Program in return for a fee. + + +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 +state 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 3 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, see `http://www.gnu.org/licenses/'. + + Also add information on how to contact you by electronic and paper +mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + PROGRAM Copyright (C) YEAR NAME OF AUTHOR + This program 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, your +program's commands might be different; for a GUI interface, you would +use an "about box". + + You should also get your employer (if you work as a programmer) or +school, if any, to sign a "copyright disclaimer" for the program, if +necessary. For more information on this, and how to apply and follow +the GNU GPL, see `http://www.gnu.org/licenses/'. + + The GNU 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 Lesser General Public License instead of this License. But first, +please read `http://www.gnu.org/philosophy/why-not-lgpl.html'. + + +File: gcj.info, Node: GNU Free Documentation License, Next: Invoking gcj, Prev: Copying, Up: Top + +GNU Free Documentation License +****************************** + + Version 1.3, 3 November 2008 + + Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. + `http://fsf.org/' + + 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 + functional and useful 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, in any medium, + that contains a notice placed by the copyright holder saying it + can be distributed under the terms of this License. Such a notice + grants a world-wide, royalty-free license, unlimited in duration, + to use that work under the conditions stated herein. The + "Document", below, refers to any such manual or work. Any member + of the public is a licensee, and is addressed as "you". You + accept the license if you copy, modify or distribute the work in a + way requiring permission under copyright law. + + 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. (Thus, 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. If a section does not fit the above definition of + Secondary then it is not allowed to be designated as Invariant. + The Document may contain zero Invariant Sections. If the Document + does not identify any Invariant Sections then there are none. + + 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 + Front-Cover Text may be at most 5 words, and a Back-Cover Text may + be at most 25 words. + + A "Transparent" copy of the Document means a machine-readable copy, + represented in a format whose specification is available to the + general public, that is suitable for revising the document + 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, or absence of + markup, has been arranged to thwart or discourage subsequent + modification by readers is not Transparent. An image format is + not Transparent if used for any substantial amount of text. 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, PostScript or PDF designed for + human modification. Examples of transparent image formats include + PNG, XCF and JPG. Opaque formats include 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, PostScript or PDF + 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. + + The "publisher" means any person or entity that distributes copies + of the Document to the public. + + A section "Entitled XYZ" means a named subunit of the Document + whose title either is precisely XYZ or contains XYZ in parentheses + following text that translates XYZ in another language. (Here XYZ + stands for a specific section name mentioned below, such as + "Acknowledgements", "Dedications", "Endorsements", or "History".) + To "Preserve the Title" of such a section when you modify the + Document means that it remains a section "Entitled XYZ" according + to this definition. + + The Document may include Warranty Disclaimers next to the notice + which states that this License applies to the Document. These + Warranty Disclaimers are considered to be included by reference in + this License, but only as regards disclaiming warranties: any other + implication that these Warranty Disclaimers may have is void and + has no effect on the meaning of this License. + + 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 (or copies in media that commonly + have printed covers) 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 computer-network location from + which the general network-using public has access to download + using public-standard network protocols a complete Transparent + copy of the Document, free of added material. 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 fewer than five), unless they release you + from this requirement. + + 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", Preserve 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. For any section Entitled "Acknowledgements" or "Dedications", + Preserve the Title of the section, and preserve in the + section all the substance and tone of each of the contributor + acknowledgements 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 to be Entitled + "Endorsements" or to conflict in title with any Invariant + Section. + + O. Preserve any Warranty Disclaimers. + + 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 + of the list of Cover Texts in the Modified Version. Only one + passage of Front-Cover Text and one of Back-Cover Text may be + added by (or through arrangements made by) any one entity. If the + Document already includes a cover text for the same cover, + previously added by you or by arrangement made by the same entity + you are acting on behalf of, you may not add another; but you may + replace the old one, on explicit permission from the previous + publisher that added the old one. + + The author(s) and publisher(s) of the Document do not by this + License give permission to use their names for publicity for or to + assert or imply endorsement of any Modified Version. + + 5. COMBINING DOCUMENTS + + You may combine the Document with other documents released under + this License, under the terms defined in section 4 above for + modified versions, provided that you include in the combination + all of the Invariant Sections of all of the original documents, + unmodified, and list them all as Invariant Sections of your + combined work in its license notice, and that you preserve all + their Warranty Disclaimers. + + The combined work need only contain one copy of this License, and + multiple identical Invariant Sections may be replaced with a single + copy. If there are multiple Invariant Sections with the same name + but different contents, make the title of each such section unique + by adding at the end of it, in parentheses, the name of the + original author or publisher of that section if known, or else a + unique number. Make the same adjustment to the section titles in + the list of Invariant Sections in the license notice of the + combined work. + + In the combination, you must combine any sections Entitled + "History" in the various original documents, forming one section + Entitled "History"; likewise combine any sections Entitled + "Acknowledgements", and any sections Entitled "Dedications". You + must delete all sections Entitled "Endorsements." + + 6. COLLECTIONS OF DOCUMENTS + + You may make a collection consisting of the Document and other + documents released under this License, and replace the individual + copies of this License in the various documents with a single copy + that is included in the collection, provided that you follow the + rules of this License for verbatim copying of each of the + documents in all other respects. + + You may extract a single document from such a collection, and + distribute it individually under this License, provided you insert + a copy of this License into the extracted document, and follow + this License in all other respects regarding verbatim copying of + that document. + + 7. AGGREGATION WITH INDEPENDENT WORKS + + A compilation of the Document or its derivatives with other + separate and independent documents or works, in or on a volume of + a storage or distribution medium, is called an "aggregate" if the + copyright resulting from the compilation is not used to limit the + legal rights of the compilation's users beyond what the individual + works permit. When the Document is included in an aggregate, this + License does not apply to the other works in the aggregate which + are not themselves derivative works of the Document. + + If the Cover Text requirement of section 3 is applicable to these + copies of the Document, then if the Document is less than one half + of the entire aggregate, the Document's Cover Texts may be placed + on covers that bracket the Document within the aggregate, or the + electronic equivalent of covers if the Document is in electronic + form. Otherwise they must appear on printed covers that bracket + the whole aggregate. + + 8. TRANSLATION + + Translation is considered a kind of modification, so you may + distribute translations of the Document under the terms of section + 4. Replacing Invariant Sections with translations requires special + permission from their copyright holders, but you may include + translations of some or all Invariant Sections in addition to the + original versions of these Invariant Sections. You may include a + translation of this License, and all the license notices in the + Document, and any Warranty Disclaimers, provided that you also + include the original English version of this License and the + original versions of those notices and disclaimers. In case of a + disagreement between the translation and the original version of + this License or a notice or disclaimer, the original version will + prevail. + + If a section in the Document is Entitled "Acknowledgements", + "Dedications", or "History", the requirement (section 4) to + Preserve its Title (section 1) will typically require changing the + actual title. + + 9. TERMINATION + + You may not copy, modify, sublicense, or distribute the Document + except as expressly provided under this License. Any attempt + otherwise to copy, modify, sublicense, or distribute it is void, + and will automatically terminate your rights under this License. + + However, if you cease all violation of this License, then your + license from a particular copyright holder is reinstated (a) + provisionally, unless and until the copyright holder explicitly + and finally terminates your license, and (b) permanently, if the + copyright holder fails to notify you of the violation by some + reasonable means prior to 60 days after the cessation. + + Moreover, your license from a particular copyright holder is + reinstated permanently if the copyright holder notifies you of the + violation by some reasonable means, this is the first time you have + received notice of violation of this License (for any work) from + that copyright holder, and you cure the violation prior to 30 days + after your receipt of the notice. + + Termination of your rights under this section does not terminate + the licenses of parties who have received copies or rights from + you under this License. If your rights have been terminated and + not permanently reinstated, receipt of a copy of some or all of + the same material does not give you any rights to use it. + + 10. FUTURE REVISIONS OF THIS LICENSE + + The Free Software Foundation may publish new, revised versions of + the GNU Free Documentation 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. See + `http://www.gnu.org/copyleft/'. + + Each version of the License is given a distinguishing version + number. If the Document specifies that a particular numbered + version of this License "or any later version" applies to it, you + have the option of following the terms and conditions either of + that specified version or of any later version that has been + published (not as a draft) by the Free Software Foundation. If + the Document does not specify a version number of this License, + you may choose any version ever published (not as a draft) by the + Free Software Foundation. If the Document specifies that a proxy + can decide which future versions of this License can be used, that + proxy's public statement of acceptance of a version permanently + authorizes you to choose that version for the Document. + + 11. RELICENSING + + "Massive Multiauthor Collaboration Site" (or "MMC Site") means any + World Wide Web server that publishes copyrightable works and also + provides prominent facilities for anybody to edit those works. A + public wiki that anybody can edit is an example of such a server. + A "Massive Multiauthor Collaboration" (or "MMC") contained in the + site means any set of copyrightable works thus published on the MMC + site. + + "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 + license published by Creative Commons Corporation, a not-for-profit + corporation with a principal place of business in San Francisco, + California, as well as future copyleft versions of that license + published by that same organization. + + "Incorporate" means to publish or republish a Document, in whole or + in part, as part of another Document. + + An MMC is "eligible for relicensing" if it is licensed under this + License, and if all works that were first published under this + License somewhere other than this MMC, and subsequently + incorporated in whole or in part into the MMC, (1) had no cover + texts or invariant sections, and (2) were thus incorporated prior + to November 1, 2008. + + The operator of an MMC Site may republish an MMC contained in the + site under CC-BY-SA on the same site at any time before August 1, + 2009, provided the MMC is eligible for relicensing. + + +ADDENDUM: How to use this License for your documents +==================================================== + +To use this License in a document you have written, include a copy of +the License in the document and put the following copyright and license +notices just after the title page: + + Copyright (C) YEAR YOUR NAME. + Permission is granted to copy, distribute and/or modify this document + under the terms of the GNU Free Documentation License, Version 1.3 + or any later version published by the Free Software Foundation; + with no Invariant Sections, no Front-Cover Texts, and no Back-Cover + Texts. A copy of the license is included in the section entitled ``GNU + Free Documentation License''. + + If you have Invariant Sections, Front-Cover Texts and Back-Cover +Texts, replace the "with...Texts." line with this: + + with the Invariant Sections being LIST THEIR TITLES, with + the Front-Cover Texts being LIST, and with the Back-Cover Texts + being LIST. + + If you have Invariant Sections without Cover Texts, or some other +combination of the three, merge those two alternatives to suit the +situation. + + If your document contains nontrivial examples of program code, we +recommend releasing these examples in parallel under your choice of +free software license, such as the GNU General Public License, to +permit their use in free software. + + +File: gcj.info, Node: Invoking gcj, Next: Compatibility, Prev: GNU Free Documentation License, Up: Top + +1 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 +* Linking:: Options for making an executable +* 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 + +1.1 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. Files in an archive + which don't end with `.class' are treated as resource files; they + are compiled into the resulting object file as `core:' URLs. + +`@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' or `--resource'. (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 + +1.2 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 text 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 important, 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). + This does not override the builtin ("boot") search path. + +`--CLASSPATH=PATH' + Deprecated synonym for `--classpath'. + +`--bootclasspath=PATH' + Where to find the standard builtin classes, such as + `java.lang.String'. + +`--extdirs=PATH' + For each directory in the PATH, place the contents of that + directory at the end of the class 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. Otherwise, + if the `CLASSPATH' environment variable is specified, then its + value is appended. Otherwise, the current directory (`"."') is + appended. + + * If `--bootclasspath' was specified, append its value. Otherwise, + append the built-in system directory, `libgcj.jar'. + + * Finally, if `--extdirs' was specified, append the contents of the + specified directories at the end of the class path. Otherwise, + append the contents of the built-in extdirs at + `$(prefix)/share/java/ext'. + + 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 override 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. + +`-fsource=VERSION' + This option is used to choose the source version accepted by + `gcj'. The default is `1.5'. + + +File: gcj.info, Node: Encodings, Next: Warnings, Prev: Input Options, Up: Invoking gcj + +1.3 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: Linking, Prev: Encodings, Up: Invoking gcj + +1.4 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. + +`-Wno-deprecated' + Warn if a deprecated class, method, or field is referred to. + +`-Wunused' + This is the same as `gcc''s `-Wunused'. + +`-Wall' + This is the same as `-Wredundant-modifiers -Wextraneous-semicolon + -Wunused'. + + +File: gcj.info, Node: Linking, Next: Code Generation, Prev: Warnings, Up: Invoking gcj + +1.5 Linking +=========== + +To turn a Java application into an executable program, you need to link +it with the needed libraries, just as for C or C++. 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. You can do that in any of these ways: + + * Specify the class containing the desired `main' method when you + link the application, using the `--main' flag, described below. + + * Link the Java package(s) into a shared library (dll) rather than an + executable. Then invoke the application using the `gij' program, + making sure that `gij' can find the libraries it needs. + + * Link the Java packages(s) with the flag `-lgij', which links in + the `main' routine from the `gij' command. This allows you to + select the class whose `main' method you want to run when you run + the application. You can also use other `gij' flags, such as `-D' + flags to set properties. Using the `-lgij' library (rather than + the `gij' program of the previous mechanism) has some advantages: + it is compatible with static linking, and does not require + configuring or installing libraries. + + These `gij' options relate to linking an executable: + +`--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. + +`-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. + +`-lgij' + Create an application whose command-line processing is that of the + `gij' command. + + This option is an alternative to using `--main'; you cannot use + both. + +`-static-libgcj' + This option causes linking to be done against a static version of + the libgcj runtime library. This option is only available if + corresponding linker support exists. + + *Caution:* Static linking of libgcj may cause essential parts of + libgcj to be omitted. Some parts of libgcj use reflection to load + classes at runtime. Since the linker does not see these + references at link time, it can omit the referred to classes. The + result is usually (but not always) a `ClassNotFoundException' + being thrown at runtime. Caution must be used when using this + option. For more details see: + `http://gcc.gnu.org/wiki/Statically%20linking%20libgcj' + + +File: gcj.info, Node: Code Generation, Next: Configure-time Options, Prev: Linking, Up: Invoking gcj + +1.6 Code Generation +=================== + +In addition to the many `gcc' options controlling code generation, +`gcj' has several options specific to itself. + +`-C' + This option is used to tell `gcj' to generate bytecode (`.class' + files) rather than object code. + +`--resource RESOURCE-NAME' + This option is used to tell `gcj' to compile the contents of a + given file to object code so it may be accessed at runtime with + the core protocol handler as `core:/RESOURCE-NAME'. Note that + RESOURCE-NAME is the name of the resource as found at runtime; for + instance, it could be used in a call to `ResourceBundle.getBundle'. + The actual file name to be compiled this way must be specified + separately. + +`-ftarget=VERSION' + This can be used with `-C' to choose the version of bytecode + emitted by `gcj'. The default is `1.5'. When not generating + bytecode, this option has no effect. + +`-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, which can improve performance for code that uses arrays + extensively. Note that this can result in unpredictable behavior + if the code in question actually does violate array bounds + constraints. It is safe to use this option if you are sure that + your code will never throw an `ArrayIndexOutOfBoundsException'. + +`-fno-store-check' + Don't generate array store checks. When storing objects into + arrays, a runtime check is normally generated in order to ensure + that the object is assignment compatible with the component type + of the array (which may not be known at compile-time). With this + option, these checks are omitted. This can improve performance + for code which stores objects into arrays frequently. It is safe + to use this option if you are sure your code will never throw an + `ArrayStoreException'. + +`-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. + +`-fno-assert' + Don't recognize the `assert' keyword. This is for compatibility + with older versions of the language specification. + +`-fno-optimize-static-class-initialization' + When the optimization level is greater or equal to `-O2', `gcj' + will try to optimize the way calls into the runtime are made to + initialize static classes upon their first use (this optimization + isn't carried out if `-C' was specified.) When compiling to native + code, `-fno-optimize-static-class-initialization' will turn this + optimization off, regardless of the optimization level in use. + +`--disable-assertions[=CLASS-OR-PACKAGE]' + Don't include code for checking assertions in the compiled code. + If `=CLASS-OR-PACKAGE' is missing disables assertion code + generation for all classes, unless overridden by a more specific + `--enable-assertions' flag. If CLASS-OR-PACKAGE is a class name, + only disables generating assertion checks within the named class + or its inner classes. If CLASS-OR-PACKAGE is a package name, + disables generating assertion checks within the named package or a + subpackage. + + By default, assertions are enabled when generating class files or + when not optimizing, and disabled when generating optimized + binaries. + +`--enable-assertions[=CLASS-OR-PACKAGE]' + Generates code to check assertions. The option is perhaps + misnamed, as you still need to turn on assertion checking at + run-time, and we don't support any easy way to do that. So this + flag isn't very useful yet, except to partially override + `--disable-assertions'. + +`-findirect-dispatch' + `gcj' has a special binary compatibility ABI, which is enabled by + the `-findirect-dispatch' option. In this mode, the code + generated by `gcj' honors the binary compatibility guarantees in + the Java Language Specification, and the resulting object files do + not need to be directly linked against their dependencies. + Instead, all dependencies are looked up at runtime. This allows + free mixing of interpreted and compiled code. + + Note that, at present, `-findirect-dispatch' can only be used when + compiling `.class' files. It will not work when compiling from + source. CNI also does not yet work with the binary compatibility + ABI. These restrictions will be lifted in some future release. + + However, if you compile CNI code with the standard ABI, you can + call it from code built with the binary compatibility ABI. + +`-fbootstrap-classes' + This option can be use to tell `libgcj' that the compiled classes + should be loaded by the bootstrap loader, not the system class + loader. By default, if you compile a class and link it into an + executable, it will be treated as if it was loaded using the + system class loader. This is convenient, as it means that things + like `Class.forName()' will search `CLASSPATH' to find the desired + class. + +`-freduced-reflection' + This option causes the code generated by `gcj' to contain a + reduced amount of the class meta-data used to support runtime + reflection. The cost of this savings is the loss of the ability to + use certain reflection capabilities of the standard Java runtime + environment. When set all meta-data except for that which is + needed to obtain correct runtime semantics is eliminated. + + For code that does not use reflection (i.e. serialization, RMI, + CORBA or call methods in the `java.lang.reflect' package), + `-freduced-reflection' will result in proper operation with a + savings in executable code size. + + JNI (`-fjni') and the binary compatibility ABI + (`-findirect-dispatch') do not work properly without full + reflection meta-data. Because of this, it is an error to use + these options with `-freduced-reflection'. + + *Caution:* If there is no reflection meta-data, code that uses a + `SecurityManager' may not work properly. Also calling + `Class.forName()' may fail if the calling method has no reflection + meta-data. + + + +File: gcj.info, Node: Configure-time Options, Prev: Code Generation, Up: Invoking gcj + +1.7 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. + +`-fcheck-references' + On some systems it's necessary to insert inline checks whenever + accessing an object via a reference. On other systems you won't + need this because null pointer accesses are caught automatically + by the processor. + +`-fuse-atomic-builtins' + On some systems, gcc can generate code for built-in atomic + operations. Use this option to force gcj to use these builtins + when compiling Java code. Where this capability is present it + should be automatically detected, so you won't usually need to use + this option. + + + +File: gcj.info, Node: Compatibility, Next: Invoking jcf-dump, Prev: Invoking gcj, Up: Top + +2 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'. + +* Menu: + +* Limitations:: +* Extensions:: + + +File: gcj.info, Node: Limitations, Next: Extensions, Up: Compatibility + +2.1 Standard features not yet supported +======================================= + +This list of compatibility issues is by no means complete. + + * `gcj' implements the JDK 1.2 language. It supports inner classes + and the new 1.4 `assert' keyword. 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. + + * `gcj' does not currently allow for piecemeal replacement of + components within `libgcj'. Unfortunately, programmers often want + to use newer versions of certain packages, such as those provided + by the Apache Software Foundation's Jakarta project. This has + forced us to place the `org.w3c.dom' and `org.xml.sax' packages + into their own libraries, separate from `libgcj'. If you intend to + use these classes, you must link them explicitly with + `-l-org-w3c-dom' and `-l-org-xml-sax'. Future versions of `gcj' + may not have this restriction. + + +File: gcj.info, Node: Extensions, Prev: Limitations, Up: Compatibility + +2.2 Extra features unique to gcj +================================ + +The main feature of `gcj' is that it can compile programs written in +the Java programming language to native code. Most extensions that +have been added are to facilitate this functionality. + + * `gcj' makes it easy and efficient to mix code written in Java and + C++. *Note About CNI::, for more info on how to use this in your + programs. + + * When you compile your classes into a shared library using + `-findirect-dispatch' then add them to the system-wide classmap.db + file using `gcj-dbtool', they will be automatically loaded by the + `libgcj' system classloader. This is the new, preferred + classname-to-library resolution mechanism. *Note Invoking + gcj-dbtool::, for more information on using the classmap database. + + * The old classname-to-library lookup mechanism is still supported + through the `gnu.gcj.runtime.VMClassLoader.library_control' + property, but it is deprecated and will likely be removed in some + future release. When trying to load a class `gnu.pkg.SomeClass' + the system classloader will first try to load the shared library + `lib-gnu-pkg-SomeClass.so', if that fails to load the class then + it will try to load `lib-gnu-pkg.so' and finally when the class is + still not loaded it will try to load `lib-gnu.so'. Note that all + `.'s will be transformed into `-'s and that searching for inner + classes starts with their outermost outer class. If the class + cannot be found this way the system classloader tries to use the + `libgcj' bytecode interpreter to load the class from the standard + classpath. This process can be controlled to some degree via the + `gnu.gcj.runtime.VMClassLoader.library_control' property; *Note + libgcj Runtime Properties::. + + * `libgcj' includes a special `gcjlib' URL type. A URL of this form + is like a `jar' URL, and looks like + `gcjlib:/path/to/shared/library.so!/path/to/resource'. An access + to one of these URLs causes the shared library to be `dlopen()'d, + and then the resource is looked for in that library. These URLs + are most useful when used in conjunction with + `java.net.URLClassLoader'. Note that, due to implementation + limitations, currently any such URL can be accessed by only one + class loader, and libraries are never unloaded. This means some + care must be exercised to make sure that a `gcjlib' URL is not + accessed by more than one class loader at once. In a future + release this limitation will be lifted, and such libraries will be + mapped privately. + + * A program compiled by `gcj' will examine the `GCJ_PROPERTIES' + environment variable and change its behavior in some ways. In + particular `GCJ_PROPERTIES' holds a list of assignments to global + properties, such as would be set with the `-D' option to `java'. + For instance, `java.compiler=gcj' is a valid (but currently + meaningless) setting. + + + +File: gcj.info, Node: Invoking jcf-dump, Next: Invoking gij, Prev: Compatibility, Up: Top + +3 Invoking jcf-dump +******************* + +This is a class file examiner, similar to `javap'. It will print +information about a number of classes, which are specified by class name +or file name. + +`-c' + Disassemble method bodies. By default method bodies are not + printed. + +`--print-constants' + Print the constant pool. When printing a reference to a constant + also print its index in the constant pool. + +`--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. + +`--help' + Print help, then exit. + +`--version' + Print version number, then exit. + +`-v, --verbose' + Print extra information while running. Implies + `--print-constants'. + + +File: gcj.info, Node: Invoking gij, Next: Invoking gcj-dbtool, Prev: Invoking jcf-dump, Up: Top + +4 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. + +`-cp PATH' +`-classpath PATH' + Set the initial class path. The class path is used for finding + class and resource files. If specified, this option overrides the + `CLASSPATH' environment variable. Note that this option is + ignored if `-jar' is used. + +`-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' + Equivalent to `-Xms'. + +`-mx=NUMBER' + Equivalent to `-Xmx'. + +`-noverify' + Do not verify compliance of bytecode with the VM specification. In + addition, this option disables type verification which is + otherwise performed on BC-ABI compiled code. + +`-X' +`-XARGUMENT' + Supplying `-X' by itself will cause `gij' to list all the + supported `-X' options. Currently these options are supported: + + `-XmsSIZE' + Set the initial heap size. + + `-XmxSIZE' + Set the maximum heap size. + + `-XssSIZE' + Set the thread stack size. + + Unrecognized `-X' options are ignored, for compatibility with + other runtimes. + +`-jar' + This indicates that the name passed to `gij' should be interpreted + as the name of a jar file, not a class. + +`--help' +`-?' + Print help, then exit. + +`--showversion' + Print version number and continue. + +`--fullversion' + Print detailed version information, then exit. + +`--version' + Print version number, then exit. + +`-verbose' +`-verbose:class' + Each time a class is initialized, print a short message on + standard error. + + `gij' also recognizes and ignores the following options, for +compatibility with existing application launch scripts: `-client', +`-server', `-hotspot', `-jrockit', `-agentlib', `-agentpath', `-debug', +`-d32', `-d64', `-javaagent', `-noclassgc', `-verify', and +`-verifyremote'. + + +File: gcj.info, Node: Invoking gcj-dbtool, Next: Invoking jv-convert, Prev: Invoking gij, Up: Top + +5 Invoking gcj-dbtool. +********************** + +`gcj-dbtool' is a tool for creating and manipulating class file mapping +databases. `libgcj' can use these databases to find a shared library +corresponding to the bytecode representation of a class. This +functionality is useful for ahead-of-time compilation of a program that +has no knowledge of `gcj'. + + `gcj-dbtool' works best if all the jar files added to it are +compiled using `-findirect-dispatch'. + + Note that `gcj-dbtool' is currently available as "preview +technology". We believe it is a reasonable way to allow +application-transparent ahead-of-time compilation, but this is an +unexplored area. We welcome your comments. + +`-n DBFILE [SIZE]' + This creates a new database. Currently, databases cannot be + resized; you can choose a larger initial size if desired. The + default size is 32,749. + +`-a DBFILE JARFILE LIB' +`-f DBFILE JARFILE LIB' + This adds a jar file to the database. For each class file in the + jar, a cryptographic signature of the bytecode representation of + the class is recorded in the database. At runtime, a class is + looked up by its signature and the compiled form of the class is + looked for in the corresponding shared library. The `-a' option + will verify that LIB exists before adding it to the database; `-f' + skips this check. + +`[`-'][`-0'] -m DBFILE DBFILE,[DBFILE]' + Merge a number of databases. The output database overwrites any + existing database. To add databases into an existing database, + include the destination in the list of sources. + + If `-' or `-0' are used, the list of files to read is taken from + standard input instead of the command line. For `-0', Input + filenames are terminated by a null character instead of by + whitespace. Useful when arguments might contain white space. The + GNU find -print0 option produces input suitable for this mode. + +`-t DBFILE' + Test a database. + +`-l DBFILE' + List the contents of a database. + +`-p' + Print the name of the default database. If there is no default + database, this prints a blank line. If LIBDIR is specified, use + it instead of the default library directory component of the + database name. + +`--help' + Print a help message, then exit. + +`--version' +`-v' + Print version information, then exit. + + + +File: gcj.info, Node: Invoking jv-convert, Next: Invoking grmic, Prev: Invoking gcj-dbtool, Up: Top + +6 Invoking jv-convert +********************* + +`jv-convert' [`OPTION'] ... [INPUTFILE [OUTPUTFILE]] + + `jv-convert' is a utility included with `libgcj' which converts a +file from one encoding to another. It is similar to the Unix `iconv' +utility. + + The encodings supported by `jv-convert' are platform-dependent. +Currently there is no way to get a list of all supported encodings. + +`--encoding NAME' +`--from NAME' + Use NAME as the input encoding. The default is the current + locale's encoding. + +`--to NAME' + Use NAME as the output encoding. The default is the `JavaSrc' + encoding; this is ASCII with `\u' escapes for non-ASCII characters. + +`-i FILE' + Read from FILE. The default is to read from standard input. + +`-o FILE' + Write to FILE. The default is to write to standard output. + +`--reverse' + Swap the input and output encodings. + +`--help' + Print a help message, then exit. + +`--version' + Print version information, then exit. + + +File: gcj.info, Node: Invoking grmic, Next: Invoking gc-analyze, Prev: Invoking jv-convert, Up: Top + +7 Invoking grmic +**************** + +`grmic' [`OPTION'] ... CLASS ... + + `grmic' is a utility included with `libgcj' which generates stubs +for remote objects. + + Note that this program isn't yet fully compatible with the JDK +`grmic'. Some options, such as `-classpath', are recognized but +currently ignored. We have left these options undocumented for now. + + Long options can also be given with a GNU-style leading `--'. For +instance, `--help' is accepted. + +`-keep' +`-keepgenerated' + By default, `grmic' deletes intermediate files. Either of these + options causes it not to delete such files. + +`-v1.1' + Cause `grmic' to create stubs and skeletons for the 1.1 protocol + version. + +`-vcompat' + Cause `grmic' to create stubs and skeletons compatible with both + the 1.1 and 1.2 protocol versions. This is the default. + +`-v1.2' + Cause `grmic' to create stubs and skeletons for the 1.2 protocol + version. + +`-nocompile' + Don't compile the generated files. + +`-verbose' + Print information about what `grmic' is doing. + +`-d DIRECTORY' + Put output files in DIRECTORY. By default the files are put in + the current working directory. + +`-help' + Print a help message, then exit. + +`-version' + Print version information, then exit. + + +File: gcj.info, Node: Invoking gc-analyze, Next: Invoking aot-compile, Prev: Invoking grmic, Up: Top + +8 Invoking gc-analyze +********************* + +`gc-analyze' [`OPTION'] ... [FILE] + + `gc-analyze' prints an analysis of a GC memory dump to standard out. + + The memory dumps may be created by calling +`gnu.gcj.util.GCInfo.enumerate(String namePrefix)' from java code. A +memory dump will be created on an out of memory condition if +`gnu.gcj.util.GCInfo.setOOMDump(String namePrefix)' is called before +the out of memory occurs. + + Running this program will create two files: `TestDump001' and +`TestDump001.bytes'. + + import gnu.gcj.util.*; + import java.util.*; + + public class GCDumpTest + { + static public void main(String args[]) + { + ArrayList<String> l = new ArrayList<String>(1000); + + for (int i = 1; i < 1500; i++) { + l.add("This is string #" + i); + } + GCInfo.enumerate("TestDump"); + } + } + + The memory dump may then be displayed by running: + + gc-analyze -v TestDump001 + +`--verbose' +`-v' + Verbose output. + +`-p TOOL-PREFIX' + Prefix added to the names of the `nm' and `readelf' commands. + +`-d DIRECTORY' + Directory that contains the executable and shared libraries used + when the dump was generated. + +`--help' + Print a help message, then exit. + +`--version' + Print version information, then exit. + + +File: gcj.info, Node: Invoking aot-compile, Next: Invoking rebuild-gcj-db, Prev: Invoking gc-analyze, Up: Top + +9 Invoking aot-compile +********************** + +`aot-compile' is a script that searches a directory for Java bytecode +(as class files, or in jars) and uses `gcj' to compile it to native +code and generate the databases from it. + +`-M, --make=PATH' + Specify the path to the `make' executable to use. + +`-C, --gcj=PATH' + Specify the path to the `gcj' executable to use. + +`-D, --dbtool=PATH' + Specify the path to the `gcj-dbtool' executable to use. + +`-m, --makeflags=FLAGS' + Specify flags to pass to `make' during the build. + +`-c, --gcjflags=FLAGS' + Specify flags to pass to `gcj' during compilation, in addition to + '-fPIC -findirect-dispatch -fjni'. + +`-l, --ldflags=FLAGS' + Specify flags to pass to `gcj' during linking, in addition to + '-Wl,-Bsymbolic'. + +`-e, --exclude=PATH' + Do not compile PATH. + + + +File: gcj.info, Node: Invoking rebuild-gcj-db, Next: About CNI, Prev: Invoking aot-compile, Up: Top + +10 Invoking rebuild-gcj-db +************************** + +`rebuild-gcj-db' is a script that merges the per-solib databases made by +`aot-compile' into one system-wide database so `gij' can find the +solibs. + + +File: gcj.info, Node: About CNI, Next: System properties, Prev: Invoking rebuild-gcj-db, Up: Top + +11 About CNI +************ + +This documents CNI, the Compiled Native Interface, which is is a +convenient way to write Java native methods using C++. This is a more +efficient, more convenient, but less portable alternative to the +standard JNI (Java Native Interface). + +* Menu: + +* Basic concepts:: Introduction to using CNI. +* Packages:: How packages are mapped to C++. +* Primitive types:: Handling primitive Java types in C++. +* Reference types:: Handling Java reference types in C++. +* Interfaces:: How Java interfaces map to C++. +* Objects and Classes:: C++ and Java classes. +* Class Initialization:: How objects are initialized. +* Object allocation:: How to create Java objects in C++. +* Memory allocation:: How to allocate and free memory. +* Arrays:: Dealing with Java arrays in C++. +* Methods:: Java methods in C++. +* Strings:: Information about Java Strings. +* Mixing with C++:: How CNI can interoperate with C++. +* Exception Handling:: How exceptions are handled. +* Synchronization:: Synchronizing between Java and C++. +* Invocation:: Starting the Java runtime from C++. +* Reflection:: Using reflection from C++. + + +File: gcj.info, Node: Basic concepts, Next: Packages, Up: About CNI + +11.1 Basic concepts +=================== + +In terms of languages features, Java is mostly a subset of C++. Java +has a few important extensions, plus a powerful standard class library, +but on the whole that does not change the basic similarity. Java is a +hybrid object-oriented language, with a few native types, in addition +to class types. It is class-based, where a class may have static as +well as per-object fields, and static as well as instance methods. +Non-static methods may be virtual, and may be overloaded. Overloading +is resolved at compile time by matching the actual argument types +against the parameter types. Virtual methods are implemented using +indirect calls through a dispatch table (virtual function table). +Objects are allocated on the heap, and initialized using a constructor +method. Classes are organized in a package hierarchy. + + All of the listed attributes are also true of C++, though C++ has +extra features (for example in C++ objects may be allocated not just on +the heap, but also statically or in a local stack frame). Because +`gcj' uses the same compiler technology as G++ (the GNU C++ compiler), +it is possible to make the intersection of the two languages use the +same ABI (object representation and calling conventions). The key idea +in CNI is that Java objects are C++ objects, and all Java classes are +C++ classes (but not the other way around). So the most important task +in integrating Java and C++ is to remove gratuitous incompatibilities. + + You write CNI code as a regular C++ source file. (You do have to use +a Java/CNI-aware C++ compiler, specifically a recent version of G++.) + +A CNI C++ source file must have: + + #include <gcj/cni.h> + +and then must include one header file for each Java class it uses, e.g.: + + #include <java/lang/Character.h> + #include <java/util/Date.h> + #include <java/lang/IndexOutOfBoundsException.h> + +These header files are automatically generated by `gcjh'. + + CNI provides some functions and macros to make using Java objects and +primitive types from C++ easier. In general, these CNI functions and +macros start with the `Jv' prefix, for example the function +`JvNewObjectArray'. This convention is used to avoid conflicts with +other libraries. Internal functions in CNI start with the prefix +`_Jv_'. You should not call these; if you find a need to, let us know +and we will try to come up with an alternate solution. + +11.1.1 Limitations +------------------ + +Whilst a Java class is just a C++ class that doesn't mean that you are +freed from the shackles of Java, a CNI C++ class must adhere to the +rules of the Java programming language. + + For example: it is not possible to declare a method in a CNI class +that will take a C string (`char*') as an argument, or to declare a +member variable of some non-Java datatype. + + +File: gcj.info, Node: Packages, Next: Primitive types, Prev: Basic concepts, Up: About CNI + +11.2 Packages +============= + +The only global names in Java are class names, and packages. A +"package" can contain zero or more classes, and also zero or more +sub-packages. Every class belongs to either an unnamed package or a +package that has a hierarchical and globally unique name. + + A Java package is mapped to a C++ "namespace". The Java class +`java.lang.String' is in the package `java.lang', which is a +sub-package of `java'. The C++ equivalent is the class +`java::lang::String', which is in the namespace `java::lang' which is +in the namespace `java'. + +Here is how you could express this: + + (// Declare the class(es), possibly in a header file: + namespace java { + namespace lang { + class Object; + class String; + ... + } + } + + class java::lang::String : public java::lang::Object + { + ... + }; + +The `gcjh' tool automatically generates the necessary namespace +declarations. + +11.2.1 Leaving out package names +-------------------------------- + +Always using the fully-qualified name of a java class can be tiresomely +verbose. Using the full qualified name also ties the code to a single +package making code changes necessary should the class move from one +package to another. The Java `package' declaration specifies that the +following class declarations are in the named package, without having +to explicitly name the full package qualifiers. The `package' +declaration can be followed by zero or more `import' declarations, which +allows either a single class or all the classes in a package to be +named by a simple identifier. C++ provides something similar with the +`using' declaration and directive. + +In Java: + + import PACKAGE-NAME.CLASS-NAME; + +allows the program text to refer to CLASS-NAME as a shorthand for the +fully qualified name: `PACKAGE-NAME.CLASS-NAME'. + +To achieve the same effect C++, you have to do this: + + using PACKAGE-NAME::CLASS-NAME; + +Java can also cause imports on demand, like this: + + import PACKAGE-NAME.*; + +Doing this allows any class from the package PACKAGE-NAME to be +referred to only by its class-name within the program text. + +The same effect can be achieved in C++ like this: + + using namespace PACKAGE-NAME; + + +File: gcj.info, Node: Primitive types, Next: Reference types, Prev: Packages, Up: About CNI + +11.3 Primitive types +==================== + +Java provides 8 "primitives" types which represent integers, floats, +characters and booleans (and also the void type). C++ has its own very +similar concrete types. Such types in C++ however are not always +implemented in the same way (an int might be 16, 32 or 64 bits for +example) so CNI provides a special C++ type for each primitive Java +type: + +*Java type* *C/C++ typename* *Description* +`char' `jchar' 16 bit Unicode character +`boolean' `jboolean' logical (true or false) values +`byte' `jbyte' 8-bit signed integer +`short' `jshort' 16 bit signed integer +`int' `jint' 32 bit signed integer +`long' `jlong' 64 bit signed integer +`float' `jfloat' 32 bit IEEE floating point number +`double' `jdouble' 64 bit IEEE floating point number +`void' `void' no value + + When referring to a Java type You should always use these C++ +typenames (e.g.: `jint') to avoid disappointment. + +11.3.1 Reference types associated with primitive types +------------------------------------------------------ + +In Java each primitive type has an associated reference type, e.g.: +`boolean' has an associated `java.lang.Boolean.TYPE' class. In order +to make working with such classes easier GCJ provides the macro +`JvPrimClass': + + -- macro: JvPrimClass type + Return a pointer to the `Class' object corresponding to the type + supplied. + + JvPrimClass(void) => java.lang.Void.TYPE + + + +File: gcj.info, Node: Reference types, Next: Interfaces, Prev: Primitive types, Up: About CNI + +11.4 Reference types +==================== + +A Java reference type is treated as a class in C++. Classes and +interfaces are handled this way. A Java reference is translated to a +C++ pointer, so for instance a Java `java.lang.String' becomes, in C++, +`java::lang::String *'. + + CNI provides a few built-in typedefs for the most common classes: +*Java type* *C++ typename* *Description* +`java.lang.Object' `jobject' Object type +`java.lang.String' `jstring' String type +`java.lang.Class' `jclass' Class type + + Every Java class or interface has a corresponding `Class' instance. +These can be accessed in CNI via the static `class$' field of a class. +The `class$' field is of type `Class' (and not `Class *'), so you will +typically take the address of it. + + Here is how you can refer to the class of `String', which in Java +would be written `String.class': + + using namespace java::lang; + doSomething (&String::class$); + + +File: gcj.info, Node: Interfaces, Next: Objects and Classes, Prev: Reference types, Up: About CNI + +11.5 Interfaces +=============== + +A Java class can "implement" zero or more "interfaces", in addition to +inheriting from a single base class. + + CNI allows CNI code to implement methods of interfaces. You can +also call methods through interface references, with some limitations. + + CNI doesn't understand interface inheritance at all yet. So, you +can only call an interface method when the declared type of the field +being called matches the interface which declares that method. The +workaround is to cast the interface reference to the right +superinterface. + + For example if you have: + + interface A + { + void a(); + } + + interface B extends A + { + void b(); + } + + and declare a variable of type `B' in C++, you can't call `a()' +unless you cast it to an `A' first. + + +File: gcj.info, Node: Objects and Classes, Next: Class Initialization, Prev: Interfaces, Up: About CNI + +11.6 Objects and Classes +======================== + +11.6.1 Classes +-------------- + +All Java classes are derived from `java.lang.Object'. C++ does not +have a unique root class, but we use the C++ class `java::lang::Object' +as the C++ version of the `java.lang.Object' Java class. All other +Java classes are mapped into corresponding C++ classes derived from +`java::lang::Object'. + + Interface inheritance (the `implements' keyword) is currently not +reflected in the C++ mapping. + +11.6.2 Object fields +-------------------- + +Each object contains an object header, followed by the instance fields +of the class, in order. The object header consists of a single pointer +to a dispatch or virtual function table. (There may be extra fields +_in front of_ the object, for example for memory management, but this +is invisible to the application, and the reference to the object points +to the dispatch table pointer.) + + The fields are laid out in the same order, alignment, and size as in +C++. Specifically, 8-bit and 16-bit native types (`byte', `short', +`char', and `boolean') are _not_ widened to 32 bits. Note that the +Java VM does extend 8-bit and 16-bit types to 32 bits when on the VM +stack or temporary registers. + + If you include the `gcjh'-generated header for a class, you can +access fields of Java classes in the _natural_ way. For example, given +the following Java class: + + public class Int + { + public int i; + public Int (int i) { this.i = i; } + public static Int zero = new Int(0); + } + + you can write: + + #include <gcj/cni.h>; + #include <Int>; + + Int* + mult (Int *p, jint k) + { + if (k == 0) + return Int::zero; // Static member access. + return new Int(p->i * k); + } + +11.6.3 Access specifiers +------------------------ + +CNI does not strictly enforce the Java access specifiers, because Java +permissions cannot be directly mapped into C++ permission. Private +Java fields and methods are mapped to private C++ fields and methods, +but other fields and methods are mapped to public fields and methods. + + +File: gcj.info, Node: Class Initialization, Next: Object allocation, Prev: Objects and Classes, Up: About CNI + +11.7 Class Initialization +========================= + +Java requires that each class be automatically initialized at the time +of the first active use. Initializing a class involves initializing +the static fields, running code in class initializer methods, and +initializing base classes. There may also be some implementation +specific actions, such as allocating `String' objects corresponding to +string literals in the code. + + The GCJ compiler inserts calls to `JvInitClass' at appropriate +places to ensure that a class is initialized when required. The C++ +compiler does not insert these calls automatically--it is the +programmer's responsibility to make sure classes are initialized. +However, this is fairly painless because of the conventions assumed by +the Java system. + + First, `libgcj' will make sure a class is initialized before an +instance of that object is created. This is one of the +responsibilities of the `new' operation. This is taken care of both in +Java code, and in C++ code. When G++ sees a `new' of a Java class, it +will call a routine in `libgcj' to allocate the object, and that +routine will take care of initializing the class. Note however that +this does not happen for Java arrays; you must allocate those using the +appropriate CNI function. It follows that you can access an instance +field, or call an instance (non-static) method and be safe in the +knowledge that the class and all of its base classes have been +initialized. + + Invoking a static method is also safe. This is because the Java +compiler adds code to the start of a static method to make sure the +class is initialized. However, the C++ compiler does not add this +extra code. Hence, if you write a native static method using CNI, you +are responsible for calling `JvInitClass' before doing anything else in +the method (unless you are sure it is safe to leave it out). + + Accessing a static field also requires the class of the field to be +initialized. The Java compiler will generate code to call +`JvInitClass' before getting or setting the field. However, the C++ +compiler will not generate this extra code, so it is your +responsibility to make sure the class is initialized before you access +a static field from C++. + + +File: gcj.info, Node: Object allocation, Next: Memory allocation, Prev: Class Initialization, Up: About CNI + +11.8 Object allocation +====================== + +New Java objects are allocated using a "class instance creation +expression", e.g.: + + new TYPE ( ... ) + + The same syntax is used in C++. The main difference is that C++ +objects have to be explicitly deleted; in Java they are automatically +deleted by the garbage collector. Using CNI, you can allocate a new +Java object using standard C++ syntax and the C++ compiler will allocate +memory from the garbage collector. If you have overloaded +constructors, the compiler will choose the correct one using standard +C++ overload resolution rules. + +For example: + + java::util::Hashtable *ht = new java::util::Hashtable(120); + + +File: gcj.info, Node: Memory allocation, Next: Arrays, Prev: Object allocation, Up: About CNI + +11.9 Memory allocation +====================== + +When allocating memory in CNI methods it is best to handle +out-of-memory conditions by throwing a Java exception. These functions +are provided for that purpose: + + -- Function: void* JvMalloc (jsize SIZE) + Calls malloc. Throws `java.lang.OutOfMemoryError' if allocation + fails. + + -- Function: void* JvRealloc (void* PTR, jsize SIZE) + Calls realloc. Throws `java.lang.OutOfMemoryError' if + reallocation fails. + + -- Function: void JvFree (void* PTR) + Calls free. + + +File: gcj.info, Node: Arrays, Next: Methods, Prev: Memory allocation, Up: About CNI + +11.10 Arrays +============ + +While in many ways Java is similar to C and C++, it is quite different +in its treatment of arrays. C arrays are based on the idea of pointer +arithmetic, which would be incompatible with Java's security +requirements. Java arrays are true objects (array types inherit from +`java.lang.Object'). An array-valued variable is one that contains a +reference (pointer) to an array object. + + Referencing a Java array in C++ code is done using the `JArray' +template, which as defined as follows: + + class __JArray : public java::lang::Object + { + public: + int length; + }; + + template<class T> + class JArray : public __JArray + { + T data[0]; + public: + T& operator[](jint i) { return data[i]; } + }; + + There are a number of `typedef's which correspond to `typedef's from +the JNI. Each is the type of an array holding objects of the relevant +type: + + typedef __JArray *jarray; + typedef JArray<jobject> *jobjectArray; + typedef JArray<jboolean> *jbooleanArray; + typedef JArray<jbyte> *jbyteArray; + typedef JArray<jchar> *jcharArray; + typedef JArray<jshort> *jshortArray; + typedef JArray<jint> *jintArray; + typedef JArray<jlong> *jlongArray; + typedef JArray<jfloat> *jfloatArray; + typedef JArray<jdouble> *jdoubleArray; + + -- Method on template<class T>: T* elements (JArray<T> ARRAY) + This template function can be used to get a pointer to the + elements of the `array'. For instance, you can fetch a pointer to + the integers that make up an `int[]' like so: + + extern jintArray foo; + jint *intp = elements (foo); + + The name of this function may change in the future. + + -- Function: jobjectArray JvNewObjectArray (jsize LENGTH, jclass + KLASS, jobject INIT) + This creates a new array whose elements have reference type. + `klass' is the type of elements of the array and `init' is the + initial value put into every slot in the array. + + using namespace java::lang; + JArray<String *> *array + = (JArray<String *> *) JvNewObjectArray(length, &String::class$, NULL); + +11.10.1 Creating arrays +----------------------- + +For each primitive type there is a function which can be used to create +a new array of that type. The name of the function is of the form: + + JvNewTYPEArray + +For example: + + JvNewBooleanArray + +can be used to create an array of Java primitive boolean types. + +The following function definition is the template for all such +functions: + + -- Function: jbooleanArray JvNewBooleanArray (jint LENGTH) + Creates an array LENGTH indices long. + + -- Function: jsize JvGetArrayLength (jarray ARRAY) + Returns the length of the ARRAY. + + +File: gcj.info, Node: Methods, Next: Strings, Prev: Arrays, Up: About CNI + +11.11 Methods +============= + +Java methods are mapped directly into C++ methods. The header files +generated by `gcjh' include the appropriate method definitions. +Basically, the generated methods have the same names and +_corresponding_ types as the Java methods, and are called in the +natural manner. + +11.11.1 Overloading +------------------- + +Both Java and C++ provide method overloading, where multiple methods in +a class have the same name, and the correct one is chosen (at compile +time) depending on the argument types. The rules for choosing the +correct method are (as expected) more complicated in C++ than in Java, +but given a set of overloaded methods generated by `gcjh' the C++ +compiler will choose the expected one. + + Common assemblers and linkers are not aware of C++ overloading, so +the standard implementation strategy is to encode the parameter types +of a method into its assembly-level name. This encoding is called +"mangling", and the encoded name is the "mangled name". The same +mechanism is used to implement Java overloading. For C++/Java +interoperability, it is important that both the Java and C++ compilers +use the _same_ encoding scheme. + +11.11.2 Static methods +---------------------- + +Static Java methods are invoked in CNI using the standard C++ syntax, +using the `::' operator rather than the `.' operator. + +For example: + + jint i = java::lang::Math::round((jfloat) 2.3); + +C++ method definition syntax is used to define a static native method. +For example: + + #include <java/lang/Integer> + java::lang::Integer* + java::lang::Integer::getInteger(jstring str) + { + ... + } + +11.11.3 Object Constructors +--------------------------- + +Constructors are called implicitly as part of object allocation using +the `new' operator. + +For example: + + java::lang::Integer *x = new java::lang::Integer(234); + + Java does not allow a constructor to be a native method. This +limitation can be coded round however because a constructor can _call_ +a native method. + +11.11.4 Instance methods +------------------------ + +Calling a Java instance method from a C++ CNI method is done using the +standard C++ syntax, e.g.: + + // First create the Java object. + java::lang::Integer *x = new java::lang::Integer(234); + // Now call a method. + jint prim_value = x->intValue(); + if (x->longValue == 0) + ... + +Defining a Java native instance method is also done the natural way: + + #include <java/lang/Integer.h> + + jdouble + java::lang:Integer::doubleValue() + { + return (jdouble) value; + } + +11.11.5 Interface methods +------------------------- + +In Java you can call a method using an interface reference. This is +supported, but not completely. *Note Interfaces::. + + +File: gcj.info, Node: Strings, Next: Mixing with C++, Prev: Methods, Up: About CNI + +11.12 Strings +============= + +CNI provides a number of utility functions for working with Java Java +`String' objects. The names and interfaces are analogous to those of +JNI. + + -- Function: jstring JvNewString (const jchar* CHARS, jsize LEN) + Returns a Java `String' object with characters from the array of + Unicode characters CHARS up to the index LEN in that array. + + -- Function: jstring JvNewStringLatin1 (const char* BYTES, jsize LEN) + Returns a Java `String' made up of LEN bytes from BYTES. + + -- Function: jstring JvNewStringLatin1 (const char* BYTES) + As above but the length of the `String' is `strlen(BYTES)'. + + -- Function: jstring JvNewStringUTF (const char* BYTES) + Returns a `String' which is made up of the UTF encoded characters + present in the C string BYTES. + + -- Function: jchar* JvGetStringChars (jstring STR) + Returns a pointer to an array of characters making up the `String' + STR. + + -- Function: int JvGetStringUTFLength (jstring STR) + Returns the number of bytes required to encode the contents of the + `String' STR in UTF-8. + + -- Function: jsize JvGetStringUTFRegion (jstring STR, jsize START, + jsize LEN, char* BUF) + Puts the UTF-8 encoding of a region of the `String' STR into the + buffer `buf'. The region to fetch is marked by START and LEN. + + Note that BUF is a buffer, not a C string. It is _not_ null + terminated. + + +File: gcj.info, Node: Mixing with C++, Next: Exception Handling, Prev: Strings, Up: About CNI + +11.13 Interoperating with C/C++ +=============================== + +Because CNI is designed to represent Java classes and methods it cannot +be mixed readily with C/C++ types. + + One important restriction is that Java classes cannot have non-Java +type instance or static variables and cannot have methods which take +non-Java types as arguments or return non-Java types. + +None of the following is possible with CNI: + + + class ::MyClass : public java::lang::Object + { + char* variable; // char* is not a valid Java type. + } + + + uint + ::SomeClass::someMethod (char *arg) + { + . + . + . + } // `uint' is not a valid Java type, neither is `char*' + +Of course, it is ok to use C/C++ types within the scope of a method: + + jint + ::SomeClass::otherMethod (jstring str) + { + char *arg = ... + . + . + . + } + +11.13.1 RawData +--------------- + +The above restriction can be problematic, so CNI includes the +`gnu.gcj.RawData' class. The `RawData' class is a "non-scanned +reference" type. In other words variables declared of type `RawData' +can contain any data and are not checked by the compiler or memory +manager in any way. + + This means that you can put C/C++ data structures (including classes) +in your CNI classes, as long as you use the appropriate cast. + +Here are some examples: + + + class ::MyClass : public java::lang::Object + { + gnu.gcj.RawData string; + + MyClass (); + gnu.gcj.RawData getText (); + void printText (); + } + + ::MyClass::MyClass () + { + char* text = ... + string = text; + } + + gnu.gcj.RawData + ::MyClass::getText () + { + return string; + } + + void + ::MyClass::printText () + { + printf("%s\n", (char*) string); + } + +11.13.2 RawDataManaged +---------------------- + +`gnu.gcj.RawDataManaged' is another type used to indicate special data +used by native code. Unlike the `RawData' type, fields declared as +`RawDataManaged' will be "marked" by the memory manager and considered +for garbage collection. + + Native data which is allocated using CNI's `JvAllocBytes()' function +and stored in a `RawDataManaged' will be automatically freed when the +Java object it is associated with becomes unreachable. + +11.13.3 Native memory allocation +-------------------------------- + + -- Function: void* JvAllocBytes (jsize SIZE) + Allocates SIZE bytes from the heap. The memory returned is zeroed. + This memory is not scanned for pointers by the garbage collector, + but will be freed if no references to it are discovered. + + This function can be useful if you need to associate some native + data with a Java object. Using a CNI's special `RawDataManaged' + type, native data allocated with `JvAllocBytes' will be + automatically freed when the Java object itself becomes + unreachable. + +11.13.4 Posix signals +--------------------- + +On Posix based systems the `libgcj' library uses several signals +internally. CNI code should not attempt to use the same signals as +doing so may cause `libgcj' and/or the CNI code to fail. + + SIGSEGV is used on many systems to generate `NullPointerExceptions'. +SIGCHLD is used internally by `Runtime.exec()'. Several other signals +(that vary from platform to platform) can be used by the memory manager +and by `Thread.interrupt()'. + + +File: gcj.info, Node: Exception Handling, Next: Synchronization, Prev: Mixing with C++, Up: About CNI + +11.14 Exception Handling +======================== + +While C++ and Java share a common exception handling framework, things +are not yet perfectly integrated. The main issue is that the run-time +type information facilities of the two languages are not integrated. + + Still, things work fairly well. You can throw a Java exception from +C++ using the ordinary `throw' construct, and this exception can be +caught by Java code. Similarly, you can catch an exception thrown from +Java using the C++ `catch' construct. + +Here is an example: + + if (i >= count) + throw new java::lang::IndexOutOfBoundsException(); + + Normally, G++ will automatically detect when you are writing C++ +code that uses Java exceptions, and handle them appropriately. +However, if C++ code only needs to execute destructors when Java +exceptions are thrown through it, GCC will guess incorrectly. Sample +problematic code: + + struct S { ~S(); }; + + extern void bar(); // Is implemented in Java and may throw exceptions. + + void foo() + { + S s; + bar(); + } + + The usual effect of an incorrect guess is a link failure, +complaining of a missing routine called `__gxx_personality_v0'. + + You can inform the compiler that Java exceptions are to be used in a +translation unit, irrespective of what it might think, by writing +`#pragma GCC java_exceptions' at the head of the file. This `#pragma' +must appear before any functions that throw or catch exceptions, or run +destructors when exceptions are thrown through them. + + +File: gcj.info, Node: Synchronization, Next: Invocation, Prev: Exception Handling, Up: About CNI + +11.15 Synchronization +===================== + +Each Java object has an implicit monitor. The Java VM uses the +instruction `monitorenter' to acquire and lock a monitor, and +`monitorexit' to release it. + + The corresponding CNI macros are `JvMonitorEnter' and +`JvMonitorExit' (JNI has similar methods `MonitorEnter' and +`MonitorExit'). + + The Java source language does not provide direct access to these +primitives. Instead, there is a `synchronized' statement that does an +implicit `monitorenter' before entry to the block, and does a +`monitorexit' on exit from the block. Note that the lock has to be +released even when the block is abnormally terminated by an exception, +which means there is an implicit `try finally' surrounding +synchronization locks. + + From C++, it makes sense to use a destructor to release a lock. CNI +defines the following utility class: + + class JvSynchronize() { + jobject obj; + JvSynchronize(jobject o) { obj = o; JvMonitorEnter(o); } + ~JvSynchronize() { JvMonitorExit(obj); } + }; + + So this Java code: + + synchronized (OBJ) + { + CODE + } + +might become this C++ code: + + { + JvSynchronize dummy (OBJ); + CODE; + } + + Java also has methods with the `synchronized' attribute. This is +equivalent to wrapping the entire method body in a `synchronized' +statement. (Alternatively, an implementation could require the caller +to do the synchronization. This is not practical for a compiler, +because each virtual method call would have to test at run-time if +synchronization is needed.) Since in `gcj' the `synchronized' +attribute is handled by the method implementation, it is up to the +programmer of a synchronized native method to handle the synchronization +(in the C++ implementation of the method). In other words, you need to +manually add `JvSynchronize' in a `native synchronized' method. + + +File: gcj.info, Node: Invocation, Next: Reflection, Prev: Synchronization, Up: About CNI + +11.16 Invocation +================ + +CNI permits C++ applications to make calls into Java classes, in +addition to allowing Java code to call into C++. Several functions, +known as the "invocation API", are provided to support this. + + -- Function: jint JvCreateJavaVM (JvVMInitArgs* VM_ARGS) + Initializes the Java runtime. This function performs essential + initialization of the threads interface, garbage collector, + exception handling and other key aspects of the runtime. It must + be called once by an application with a non-Java `main()' + function, before any other Java or CNI calls are made. It is + safe, but not recommended, to call `JvCreateJavaVM()' more than + once provided it is only called from a single thread. The VMARGS + parameter can be used to specify initialization parameters for the + Java runtime. It may be `NULL'. + + JvVMInitArgs represents a list of virtual machine initialization + arguments. `JvCreateJavaVM()' ignores the version field. + + typedef struct JvVMOption + { + // a VM initialization option + char* optionString; + // extra information associated with this option + void* extraInfo; + } JvVMOption; + + typedef struct JvVMInitArgs + { + // for compatibility with JavaVMInitArgs + jint version; + + // number of VM initialization options + jint nOptions; + + // an array of VM initialization options + JvVMOption* options; + + // true if the option parser should ignore unrecognized options + jboolean ignoreUnrecognized; + } JvVMInitArgs; + + `JvCreateJavaVM()' returns `0' upon success, or `-1' if the + runtime is already initialized. + + _Note:_ In GCJ 3.1, the `vm_args' parameter is ignored. It is + recognized and used as of release 4.0. + + -- Function: java::lang::Thread* JvAttachCurrentThread (jstring NAME, + java::lang::ThreadGroup* GROUP) + Registers an existing thread with the Java runtime. This must be + called once from each thread, before that thread makes any other + Java or CNI calls. It must be called after `JvCreateJavaVM'. NAME + specifies a name for the thread. It may be `NULL', in which case a + name will be generated. GROUP is the ThreadGroup in which this + thread will be a member. If it is `NULL', the thread will be a + member of the main thread group. The return value is the Java + `Thread' object that represents the thread. It is safe to call + `JvAttachCurrentThread()' more than once from the same thread. If + the thread is already attached, the call is ignored and the current + thread object is returned. + + -- Function: jint JvDetachCurrentThread () + Unregisters a thread from the Java runtime. This should be called + by threads that were attached using `JvAttachCurrentThread()', + after they have finished making calls to Java code. This ensures + that any resources associated with the thread become eligible for + garbage collection. This function returns `0' upon success, or + `-1' if the current thread is not attached. + +11.16.1 Handling uncaught exceptions +------------------------------------ + +If an exception is thrown from Java code called using the invocation +API, and no handler for the exception can be found, the runtime will +abort the application. In order to make the application more robust, it +is recommended that code which uses the invocation API be wrapped by a +top-level try/catch block that catches all Java exceptions. + +11.16.2 Example +--------------- + +The following code demonstrates the use of the invocation API. In this +example, the C++ application initializes the Java runtime and attaches +itself. The `java.lang.System' class is initialized in order to access +its `out' field, and a Java string is printed. Finally, the thread is +detached from the runtime once it has finished making Java calls. +Everything is wrapped with a try/catch block to provide a default +handler for any uncaught exceptions. + + The example can be compiled with `c++ -c test.cc; gcj test.o'. + + // test.cc + #include <gcj/cni.h> + #include <java/lang/System.h> + #include <java/io/PrintStream.h> + #include <java/lang/Throwable.h> + + int main(int argc, char *argv[]) + { + using namespace java::lang; + + try + { + JvCreateJavaVM(NULL); + JvAttachCurrentThread(NULL, NULL); + + String *message = JvNewStringLatin1("Hello from C++"); + JvInitClass(&System::class$); + System::out->println(message); + + JvDetachCurrentThread(); + } + catch (Throwable *t) + { + System::err->println(JvNewStringLatin1("Unhandled Java exception:")); + t->printStackTrace(); + } + } + + +File: gcj.info, Node: Reflection, Prev: Invocation, Up: About CNI + +11.17 Reflection +================ + +Reflection is possible with CNI code, it functions similarly to how it +functions with JNI. + + The types `jfieldID' and `jmethodID' are as in JNI. + +The functions: + + * `JvFromReflectedField', + + * `JvFromReflectedMethod', + + * `JvToReflectedField' + + * `JvToFromReflectedMethod' + +will be added shortly, as will other functions corresponding to JNI. + + +File: gcj.info, Node: System properties, Next: Resources, Prev: About CNI, Up: Top + +12 System properties +******************** + +The runtime behavior of the `libgcj' library can be modified by setting +certain system properties. These properties can be compiled into the +program using the `-DNAME[=VALUE]' option to `gcj' or by setting them +explicitly in the program by calling the +`java.lang.System.setProperty()' method. Some system properties are +only used for informational purposes (like giving a version number or a +user name). A program can inspect the current value of a property by +calling the `java.lang.System.getProperty()' method. + +* Menu: + +* Standard Properties:: Standard properties supported by `libgcj' +* GNU Classpath Properties:: Properties found in Classpath based libraries +* libgcj Runtime Properties:: Properties specific to `libgcj' + + +File: gcj.info, Node: Standard Properties, Next: GNU Classpath Properties, Up: System properties + +12.1 Standard Properties +======================== + +The following properties are normally found in all implementations of +the core libraries for the Java language. + +`java.version' + The `libgcj' version number. + +`java.vendor' + Set to `The Free Software Foundation, Inc.' + +`java.vendor.url' + Set to `http://gcc.gnu.org/java/'. + +`java.home' + The directory where `gcj' was installed. Taken from the `--prefix' + option given to `configure'. + +`java.class.version' + The class format version number supported by the libgcj byte code + interpreter. (Currently `46.0') + +`java.vm.specification.version' + The Virtual Machine Specification version implemented by `libgcj'. + (Currently `1.0') + +`java.vm.specification.vendor' + The name of the Virtual Machine specification designer. + +`java.vm.specification.name' + The name of the Virtual Machine specification (Set to `Java + Virtual Machine Specification'). + +`java.vm.version' + The `gcj' version number. + +`java.vm.vendor' + Set to `The Free Software Foundation, Inc.' + +`java.vm.name' + Set to `GNU libgcj'. + +`java.specification.version' + The Runtime Environment specification version implemented by + `libgcj'. (Currently set to `1.3') + +`java.specification.vendor' + The Runtime Environment specification designer. + +`java.specification.name' + The name of the Runtime Environment specification (Set to `Java + Platform API Specification'). + +`java.class.path' + The paths (jar files, zip files and directories) used for finding + class files. + +`java.library.path' + Directory path used for finding native libraries. + +`java.io.tmpdir' + The directory used to put temporary files in. + +`java.compiler' + Name of the Just In Time compiler to use by the byte code + interpreter. Currently not used in `libgcj'. + +`java.ext.dirs' + Directories containing jar files with extra libraries. Will be + used when resolving classes. + +`java.protocol.handler.pkgs' + A `|' separated list of package names that is used to find classes + that implement handlers for `java.net.URL'. + +`java.rmi.server.codebase' + A list of URLs that is used by the `java.rmi.server.RMIClassLoader' + to load classes from. + +`jdbc.drivers' + A list of class names that will be loaded by the + `java.sql.DriverManager' when it starts up. + +`file.separator' + The separator used in when directories are included in a filename + (normally `/' or `\' ). + +`file.encoding' + The default character encoding used when converting platform + native files to Unicode (usually set to `8859_1'). + +`path.separator' + The standard separator used when a string contains multiple paths + (normally `:' or `;'), the string is usually not a valid character + to use in normal directory names.) + +`line.separator' + The default line separator used on the platform (normally `\n', + `\r' or a combination of those two characters). + +`policy.provider' + The class name used for the default policy provider returned by + `java.security.Policy.getPolicy'. + +`user.name' + The name of the user running the program. Can be the full name, + the login name or empty if unknown. + +`user.home' + The default directory to put user specific files in. + +`user.dir' + The current working directory from which the program was started. + +`user.language' + The default language as used by the `java.util.Locale' class. + +`user.region' + The default region as used by the `java.util.Local' class. + +`user.variant' + The default variant of the language and region local used. + +`user.timezone' + The default timezone as used by the `java.util.TimeZone' class. + +`os.name' + The operating system/kernel name that the program runs on. + +`os.arch' + The hardware that we are running on. + +`os.version' + The version number of the operating system/kernel. + +`awt.appletWarning' + The string to display when an untrusted applet is displayed. + Returned by `java.awt.Window.getWarningString()' when the window is + "insecure". + +`awt.toolkit' + The class name used for initializing the default + `java.awt.Toolkit'. Defaults to `gnu.awt.gtk.GtkToolkit'. + +`http.proxyHost' + Name of proxy host for http connections. + +`http.proxyPort' + Port number to use when a proxy host is in use. + + + +File: gcj.info, Node: GNU Classpath Properties, Next: libgcj Runtime Properties, Prev: Standard Properties, Up: System properties + +12.2 GNU Classpath Properties +============================= + +`libgcj' is based on the GNU Classpath (Essential Libraries for Java) a +GNU project to create free core class libraries for use with virtual +machines and compilers for the Java language. The following properties +are common to libraries based on GNU Classpath. + +`gcj.dumpobject' + Enables printing serialization debugging by the + `java.io.ObjectInput' and `java.io.ObjectOutput' classes when set + to something else then the empty string. Only used when running a + debug build of the library. + +`gnu.classpath.vm.shortname' + This is a succinct name of the virtual machine. For `libgcj', + this will always be `libgcj'. + +`gnu.classpath.home.url' + A base URL used for finding system property files (e.g., + `classpath.security'). By default this is a `file:' URL pointing + to the `lib' directory under `java.home'. + + + +File: gcj.info, Node: libgcj Runtime Properties, Prev: GNU Classpath Properties, Up: System properties + +12.3 libgcj Runtime Properties +============================== + +The following properties are specific to the `libgcj' runtime and will +normally not be found in other core libraries for the java language. + +`java.fullversion' + The combination of `java.vm.name' and `java.vm.version'. + +`java.vm.info' + Same as `java.fullversion'. + +`impl.prefix' + Used by the `java.net.DatagramSocket' class when set to something + else then the empty string. When set all newly created + `DatagramSocket's will try to load a class + `java.net.[impl.prefix]DatagramSocketImpl' instead of the normal + `java.net.PlainDatagramSocketImpl'. + +`gnu.gcj.progname' + The class or binary name that was used to invoke the program. This + will be the name of the "main" class in the case where the `gij' + front end is used, or the program binary name in the case where an + application is compiled to a native binary. + +`gnu.gcj.user.realname' + The real name of the user, as taken from the password file. This + may not always hold only the user's name (as some sites put extra + information in this field). Also, this property is not available + on all platforms. + +`gnu.gcj.runtime.NameFinder.use_addr2line' + Whether an external process, `addr2line', should be used to + determine line number information when tracing the stack. Setting + this to `false' may suppress line numbers when printing stack + traces and when using the java.util.logging infrastructure. + However, performance may improve significantly for applications + that print stack traces or make logging calls frequently. + +`gnu.gcj.runtime.NameFinder.show_raw' + Whether the address of a stack frame should be printed when the + line number is unavailable. Setting this to `true' will cause the + name of the object and the offset within that object to be printed + when no line number is available. This allows for off-line + decoding of stack traces if necessary debug information is + available. The default is `false', no raw addresses are printed. + +`gnu.gcj.runtime.NameFinder.remove_unknown' + Whether stack frames for non-java code should be included in a + stack trace. The default value is `true', stack frames for + non-java code are suppressed. Setting this to `false' will cause + any non-java stack frames to be printed in addition to frames for + the java code. + +`gnu.gcj.runtime.VMClassLoader.library_control' + This controls how shared libraries are automatically loaded by the + built-in class loader. If this property is set to `full', a full + search is done for each requested class. If this property is set + to `cache', then any failed lookups are cached and not tried again. + If this property is set to `never' (the default), then lookups are + never done. For more information, *Note Extensions::. + +`gnu.gcj.runtime.endorsed.dirs' + This is like the standard `java.endorsed.dirs', property, but + specifies some extra directories which are searched after the + standard endorsed directories. This is primarily useful for + telling `libgcj' about additional libraries which are ordinarily + incorporated into the JDK, and which should be loaded by the + bootstrap class loader, but which are not yet part of `libgcj' + itself for some reason. + +`gnu.gcj.jit.compiler' + This is the full path to `gcj' executable which should be used to + compile classes just-in-time when `ClassLoader.defineClass' is + called. If not set, `gcj' will not be invoked by the runtime; + this can also be controlled via `Compiler.disable'. + +`gnu.gcj.jit.options' + This is a space-separated string of options which should be passed + to `gcj' when in JIT mode. If not set, a sensible default is + chosen. + +`gnu.gcj.jit.cachedir' + This is the directory where cached shared library files are + stored. If not set, JIT compilation is disabled. This should + never be set to a directory that is writable by any other user. + +`gnu.gcj.precompiled.db.path' + This is a sequence of file names, each referring to a file created + by `gcj-dbtool'. These files will be used by `libgcj' to find + shared libraries corresponding to classes that are loaded from + bytecode. `libgcj' often has a built-in default database; it can + be queried using `gcj-dbtool -p'. + + + +File: gcj.info, Node: Resources, Next: Index, Prev: System properties, Up: Top + +13 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. + + +File: gcj.info, Node: Index, Prev: Resources, Up: Top + +Index +***** + + +* Menu: + +* class path: Input Options. (line 6) +* class$: Reference types. (line 20) +* elements on template<class T>: Arrays. (line 46) +* FDL, GNU Free Documentation License: GNU Free Documentation License. + (line 6) +* GCJ_PROPERTIES: Extensions. (line 56) +* jclass: Reference types. (line 16) +* jobject: Reference types. (line 16) +* jstring: Reference types. (line 16) +* JvAllocBytes: Mixing with C++. (line 99) +* JvAttachCurrentThread: Invocation. (line 55) +* JvCreateJavaVM: Invocation. (line 11) +* JvDetachCurrentThread: Invocation. (line 68) +* JvFree: Memory allocation. (line 19) +* JvGetArrayLength: Arrays. (line 86) +* JvGetStringChars: Strings. (line 25) +* JvGetStringUTFLength: Strings. (line 29) +* JvGetStringUTFRegion: Strings. (line 34) +* JvMalloc: Memory allocation. (line 11) +* JvNewBooleanArray: Arrays. (line 83) +* JvNewObjectArray: Arrays. (line 57) +* JvNewString: Strings. (line 11) +* JvNewStringLatin1: Strings. (line 15) +* JvNewStringUTF: Strings. (line 21) +* JvPrimClass: Primitive types. (line 36) +* JvRealloc: Memory allocation. (line 15) + + + +Tag Table: +Node: Top2810 +Node: Copying4229 +Node: GNU Free Documentation License41779 +Node: Invoking gcj66922 +Node: Input and output files67685 +Node: Input Options69211 +Node: Encodings72485 +Node: Warnings73691 +Node: Linking74804 +Node: Code Generation77743 +Node: Configure-time Options84523 +Node: Compatibility86263 +Node: Limitations86747 +Node: Extensions88329 +Node: Invoking jcf-dump91423 +Node: Invoking gij92368 +Node: Invoking gcj-dbtool95619 +Node: Invoking jv-convert98085 +Node: Invoking grmic99164 +Node: Invoking gc-analyze100550 +Node: Invoking aot-compile101991 +Node: Invoking rebuild-gcj-db102940 +Node: About CNI103250 +Node: Basic concepts104709 +Node: Packages107605 +Node: Primitive types109933 +Node: Reference types111611 +Node: Interfaces112700 +Node: Objects and Classes113611 +Node: Class Initialization115806 +Node: Object allocation118148 +Node: Memory allocation118938 +Node: Arrays119570 +Node: Methods122380 +Node: Strings125201 +Node: Mixing with C++126705 +Node: Exception Handling130176 +Node: Synchronization131810 +Node: Invocation133800 +Node: Reflection138736 +Node: System properties139197 +Node: Standard Properties140074 +Node: GNU Classpath Properties144506 +Node: libgcj Runtime Properties145553 +Node: Resources150055 +Node: Index150893 + +End Tag Table |