---
name: "bock"
section: "1"
platform: "linux"
package: "bock"
version: "0.20.2.6"
release: "Debian 3.1 (Sarge)"
platforms: ["linux"]
url: "https://new.carta.tech/bock"
---

# bock(1)

bootstrap-only compiler for a subset of Java(tm)

## NAME

bock - bootstrap-only compiler for a subset of Java(tm)

## SYNOPSIS

**bock** \[**-s** *start-class*\] \[**-o** *output-file*\] *java-file*...

## DESCRIPTION

**BOCK** reads all the *java-file*s specified on its command line, parses them as source code in a language which is a subset of the Java(tm) language, and writes an equivalent C program as output.

Please note that **BOCK** is **not** meant as a production compiler.  It is a throw-away first-attempt compiler.  The second attempt, **Jackal**, will be written after **BOCK** is capable of compiling a reasonable subset of Java(tm) programs. **Jackal** will be written in the Java(tm) subset which **BOCK** can compile, resulting in a Java(tm) system which can be bootstrapped entirely from a C-only environment.

**BOCK** is a somewhat user-unfriendly command; it does not include the standard library automatically, and it does not compile its C output into native code automatically. For a command which does these things, see [**jcomp**(1)](/jcomp/1.md).

## OPTIONS

- \-s

  Specifies the name of the class whose **main()** function should be called when the program is run. If not specified, *Test* is used.

- \-o

  Specifies which file to write generated C to.  If not specified, **BOCK** writes compiled code to its standard output.

## FILES

**BOCK** does not use any external files other than those specified on its command line.

There is a subset of the Java standard library in */usr/share/bock/lib/\**. No extra files are needed to implement the library's native methods.

## SEE ALSO

The forthcoming **Jackal** compiler for the Java(tm) language.

[**jcomp**(1)](/jcomp/1.md), */usr/doc/bock/\**.

## DIAGNOSTICS

If **BOCK** detects an error or a construct it cannot compile, it writes a message to its standard error output and terminates with a non-zero exit code.  There are many errors which **BOCK** does not detect.

## BUGS

**BOCK** does not implement the Java(tm) language as specified. The differences are mostly commented throughout the code.  The most significant differences from Java(tm) 1.0 are:

- •

  Very little error checking

- •

  No floating point support

- •

  No multithreading or synchronisation

- •

  No labeled statements (and thus no break or continue with label)

- •

  Et cetera; see */usr/doc/bock/BUGS* for more

Because this compiler is only intended for bootstrapping a real, self-hosted Java(tm) compiler system, I don't intend to remedy these deficiencies. **BOCK** does not claim to be a standards-compliant Java(tm) compiler.

## AUTHOR

**BOCK** was written by Charles Briscoe-Smith.  I own the copyright to this program and its accompanying documentation.  Please see the file /usr/doc/bock/copyright for more information.

"Java", "Sun" and "Sun Microsystems" are trademarks or registered trademarks of Sun Microsystems, Inc.  This program was written with reference to Gosling, Joy and Steele's "The Java Language Specification", but without reference to Sun's JDK or any other Sun Microsystems code.

This compiler may infringe on patents owned by Sun Microsystems or others, and it is certainly based on Sun copyrighted material (namely, the LALR(1) grammar from "The Java Language Specification").  According to the licence notice in the front of "The Java Language Specification", I am licenced to use such of Sun's intellectual property as is necessary to practice the Java(tm) language specification, provided that any implementation is fully compliant with the specification.  I therefore make this request to Sun's legal department: please do not sue me for failing to make **BOCK** fully compliant.  It's only a (not so) quick hack.