GNU Compiler for Java

GNU Compiler for Java
Gcj2.png
Developer(s) The GNU Project
Stable release
6.2[1] / August 22, 2016; 2 months ago (2016-08-22)
Preview release
7.0 / May 22, 2016; 5 months ago (2016-05-22)
Operating system Unix-like
Type Compiler
License GNU GPL
Website gcc.gnu.org/java

The GNU Compiler for Java (GCJ) was a free compiler for the Java programming language and part of the GNU Compiler Collection.[2][3]

GCJ could compile Java source code to Java Virtual Machine bytecode or to machine code for a number of CPU architectures. It could also compile class files and whole JARs that contain bytecode into machine code.[4][5]

History

The GCJ runtime-libraries original source is from GNU Classpath project, but there is a code difference between the libgcj libraries. GCJ 4.3 uses the Eclipse Compiler for Java as a front-end.[6]

In 2007, a lot of work was done to implement support for Java's two graphical APIs in GNU Classpath: AWT and Swing. Software support for AWT is still in development. "Once AWT support is working then Swing support can be considered. There is at least one free-software partial implementations of Swing that may be usable.".[7] The GNU CLASSPATH was never completed to even Java 1.2 status and now appears to have been abandoned completely.

As of 2015, there were no new developments announced from GCJ[8] and the product was in deep maintenance mode.[9] In 2016, GCJ was in the process of being removed from GCC[10] and was deleted in October.[11]

Performance

The compilation function in GCJ should have a faster start-up time than the equivalent bytecode launched in a JVM when compiling Java code into machine code.[12]

Compiled Native Interface (CNI)

The Compiled Native Interface (CNI), previously named "Cygnus Native Interface", is a software framework for the GCJ that allows Java code to call, and be called, by native applications (programs specific to a hardware and operating-system platform) and libraries written in C++.

CNI closely resembles the JNI (Java Native Interface) framework which comes as a standard with various Java virtual machines.

Comparison of language use

The authors of CNI claim for various advantages over JNI:[13]

CNI depends on Java classes appearing as C++ classes. For example,[14] given a Java class,

public class Int
{
   public int i;
   public Int(int i) { this.i = i; }
   public static Int zero = new Int(0);
}

one can use the class thus:

#include <gcj/cni.h>
#include <Int>

Int *mult(Int *p, int k)
{
  if (k == 0)
    return Int::zero;  // Static member access.
  return new Int(p->i * k);
}

See also

References

  1. ^ "GCC Releases – GNU Project – Free Software Foundation (FSF)". 
  2. ^ https://gcc.gnu.org/java/
  3. ^ Campbell, Bill (2013). Introduction to Compiler Construction in a Java World. CRC Press Taylor & Francis Group. ISBN 978-1-4398-6088-5. Retrieved 2014-02-06. 
  4. ^ http://www.linuxjournal.com/article/4860
  5. ^ http://freecode.com/projects/gcj
  6. ^ "gcj to use Eclipse compiler as a front end". 2007-01-08. Retrieved 2007-05-20. 
  7. ^ The GCJ FAQ - GNU Project - Free Software Foundation (FSF)
  8. ^ GCJ: News
  9. ^ GCC Looks To Turn Off Java, Replace With Go Or ADA
  10. ^ https://gcc.gnu.org/ml/gcc-patches/2016-09/msg00602.html
  11. ^ Tromey, Tom (October 2, 2016). "The Deletion of gcj". The Cliffs of Inanity. Retrieved October 3, 2016. 
  12. ^ GCJ: The GNU Static Java Compiler
  13. ^ The GCJ FAQ - GNU Project - Free Software Foundation (FSF)
  14. ^ The example comes from: https://gcc.gnu.org/onlinedocs/gcj/Objects-and-Classes.html#Objects-and-Classes

External links

fonte: https://web.archive.org/web/20161116084636/https://en.wikipedia.org/wiki/GNU_Compiler_for_Java