gcj-dbtool (1)

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NAME

gcj-dbtool - Manipulate class file mapping databases for libgcj

SYNOPSIS

gcj-dbtool [] ...

gcj-dbtool [-0] [-] [-n] [-a] [-f]
  [-t] [-l] [-p [

]]
  [-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) 2001-2016 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document under the terms of the

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

's Front-Cover Text is:

     A GNU Manual

(b) The

'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.