NAME

       gcj-dbtool - Manipulate class file mapping databases for libgcj

SYNOPSIS

       gcj-dbtool OPTION DBFILE [MORE] ...

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

DESCRIPTION

       "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

       -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.

SEE ALSO

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

COPYRIGHT

       Copyright (c) 2001-2013 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.

gcc-4.8                                            2015-06-23                                      GCJ-DBTOOL(1)