gcj-dbtool - Manipulate class file mapping databases for libgcj


   gcj-dbtool OPTION DBFILE [MORE] ...

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


   "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.


       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 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

       Print a help message, then exit.

   -v  Print version information, then exit.


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


   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.


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