(gcj-4.4.info)Invoking gcj-dbtool

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5 Invoking gcj-dbtool.
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`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.