GCJ-DBTOOL

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.

−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.

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

Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.

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(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
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