===============
OBTAINING CHORD
===============

You can either obtain pre-built binaries of Chord or you can obtain
the source code of Chord and build it yourself.  Both these options
are described below.

===================
BINARY INSTALLATION
===================

To obtain Chord's pre-built binaries, download and uncompress file
http://jchord.googlecode.com/files/chord-bin-2.0.tar.gz.  It contains
the following files:

- chord.jar, which contains the class files of Chord and of libraries
  used by Chord.
- libbuddy.so, buddy.dll, and libbuddy.dylib: you can keep one of
  these files depending upon whether you intend to run Chord on Linux,
  Windows/Cygwin, or MacOS, respectively.  These files are needed only
  if you want BDD library BuDDy to be used when the BDD-based Datalog
  solver bddbddb in Chord runs analyses written in Datalog.
- libchord_instr_agent.so: this file is needed only if you want the
  JVMTI-based bytecode instrumentation agent to be used when Chord
  runs dynamic analyses.

Novice users can ignore items (2) and (3) until they become more
familiar with Chord.  The binaries mentioned in items (2) and (3)
might not be compatible with your machine, in which case you can
either forgo using them (with hardly any noticeable difference in
functionality), or you can download the sources and build them
yourself, as described below.

===================
SOURCE INSTALLATION
===================

To obtain Chord's source code, download and uncompress file
http://jchord.googlecode.com/files/chord-src-2.0.tar.gz.  It contains
Chord's source code and jars of libraries used by Chord.

If you also want the source code of libraries used by Chord (e.g.,
joeq, javassist, bddbddb, etc.), download and uncompress file
http://jchord.googlecode.com/files/chord-libsrc-2.0.tar.gz.

Alternatively, you can obtain the latest development snapshot from the
SVN repository by running the following command:

svn checkout http://jchord.googlecode.com/svn/trunk/ chord

Instead of checking out the entire trunk/, which contains several
sub-directories, you can check out specific sub-directories:

- main/ contains Chord's source code and jars of libraries used by Chord.
- libsrc/ contains the source code of libraries used by Chord (e.g.,
  joeq, javassist, bddbddb, etc.).
- test/ contains Chord's regression tests.
- many more; these might eventually move into main/.

Files chord-2.0-src.tar.gz and chord-2.0-libsrc.tar.gz mentioned above
are essentially stable releases of the main/ and libsrc/ directories,
respectively.

=========================
COMPILING THE SOURCE CODE
=========================

Compiling Chord's source code requires the following software:

- A JVM with JDK 5 or higher, e.g. IBM J9 or Oracle HotSpot.
- Apache Ant, a Java build tool.

Chord's main directory contains a file named build.xml which is
interpreted by Apache Ant.  To see the various possible targets,
simply run command "ant" in that directory.

To compile Chord, run command "ant compile" in the same directory.
This will compile Chord's Java sources from src/ to class files in
classes/, as well as build a jar file chord.jar that contains these
class files as well as the those in the jars of libraries that are
used by Chord and are provided under lib/ (e.g., joeq.jar,
javassist.jar, bddbddb.jar, etc.).  Additionally:

- If system property chord.use.buddy is set to true, then the C source
  code of BDD library BuDDy from directory bdd/ will be compiled to a
  shared library named libbuddy.so on Linux, buddy.dll on Windows, and
  libbuddy.dylib on MacOS; this library is used by BDD-based Datalog
  solver bddbddb in Chord for running analyses written in Datalog.

- If system property chord.use.jvmti is set to true, then the C++
  source code of the JVMTI-based bytecode instrumentation agent from
  directory agent/ will be compiled to a shared library named
  libchord_instr_agent.so on all architectures; this agent is used in
  Chord for computing analysis scope dynamically and for running
  dynamic analyses.

Properties chord.use.buddy and chord.use.jvmti are defined in file
chord.properties in Chord's main directory.  The default value of both
these properties is false.  If you set either of them to true, then
you will also need a utility like GNU Make (to run the Makefile's in
directories bdd/ and agent/) and a C++ compiler.

=============
RUNNING CHORD
=============

Running Chord requires a JVM with JDK 5 or higher. There are two
equivalent ways to run Chord.  One way, which is available only in the
source installation of Chord, is to run the following command in
Chord's main directory:

ant -D<key1>=<value1> ... -D<keyN>=<valueN> run

The above requires Apache Ant (a Java build tool) to be installed on
your machine.  The alternative, which does not require Apache Ant and
is available in both the source and binary installations of Chord, is
to run the following command:

java -cp <...>/chord.jar -D<key1>=<value1> ... -D<keyN>=<valueN>
chord.project.Boot

where <...> denotes the absolute or relative path of the directory
containing file chord.jar; that directory is also expected to contain
any other binaries in Chord's installation (e.g., libbuddy.so and
libchord_instr_agent.so).

Each "-D<key>=<value>" argument above sets the system property named
<key> to the value denoted by <value>.  The only way to specify inputs
to Chord is via system properties; there is no command-line argument
processing.  All system properties recognized by Chord are described
at http://chord.stanford.edu/user_guide/properties.html.

QUICK START
===========

To ensure that Chord is installed successfully, run it on a provided
example Java program as follows.  First run command "ant" in directory
examples/hello_world/.  This will compile the Java source code of that
example.  Then, run the following command in Chord's main directory:

ant -Dchord.work.dir=examples/hello_world -Dchord.run.analyses=cipa-0cfa-dlog run

This will run a basic may-alias and call-graph analysis (called 0CFA)
on the example Java program.  It will produce somewhat verbose output
of the form:

    Buildfile: build.xml

    run:
         [java] Chord run initiated at: Mar 13, 2011 10:31:08 PM
         [java] ENTER: cipa-0cfa-dlog
         ... (truncated here for brevity)
         [java] LEAVE: cipa-0cfa-dlog
         [java] Chord run completed at: Mar 13, 2011 10:31:36 PM
         [java] Total time: 00:00:27:671 hh:mm:ss:ms

    BUILD SUCCESSFUL
    Total time: 28 seconds

To reduce the verbosity of Chord's output, set -Dchord.verbose=0 on
the command line.

The names and descriptions of analyses besides cipa-0cfa-dlog that are
provided in Chord are available here:

http://chord.stanford.edu/user_guide/predefined_analyses.html

To setup your own Java program for analysis using Chord, see here:

http://chord.stanford.edu/user_guide/example.html

To write your own analyses, possibly atop provided ones, see here:

http://chord.stanford.edu/user_guide/analyses.html

FURTHER DOCUMENTATION
=====================

Chord's User Guide is available at:

http://chord.stanford.edu/user_guide/

The Javadoc of Chord's source code is available at:

http://chord.stanford.edu/javadoc/

For questions about Chord, send email to
<chord-discuss@googlegroups.com>, or browse previous postings at:

http://groups.google.com/group/chord-discuss/

Posting does not require membership but posts by non-members are
moderated to avoid spamming group members.