GCJ-DBTOOL(1)                        GNU                       GCJ-DBTOOL(1)

NAME         top

       gcj-dbtool - Manipulate class file mapping databases for libgcj

SYNOPSIS         top

       gcj-dbtool OPTION DBFILE [MORE] ...

       gcj-dbtool [-0] [-] [-n] [-a] [-f]
         [-t] [-l] [-p [LIBDIR]]
         [-v] [-m] [--version] [--help]

DESCRIPTION         top

       "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.

OPTIONS         top

       -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.

           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

       -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.

           Print a help message, then exit.

       -v  Print version information, then exit.

SEE ALSO         top

       gcc(1), gcj(1), gcjh(1), jcf-dump(1), gfdl(7), and the Info entries
       for gcj and gcc.

COPYRIGHT         top

       Copyright (c) 2001-2016 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 man page gfdl(7).

       (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.

COLOPHON         top

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gcc-6.3.0                        2016-12-21                    GCJ-DBTOOL(1)