This is Leon 0.2.0

Getting Started

This section gives a very quick overview of how to build and use Leon, refer to the following sections if you wish (or need) more detailed information.

To build it, you will need, for example, the following:

• Java Runtime Environment, from Oracle, e.g. Version 7 Update 5 (to run xsbt and scala)
• Scala, from Typesafe, e.g. version 2.9.1
• xsbt, e.g. version 0.11.3: download sbt-launch.jar, run it with java -jar (to built Leon)
• a recent GLIBC3 or later, works with e.g. apt-get (for Z3)
• GNU Multiprecision library, e.g. gmp3, works with e.g. apt-get (for Z3)

The following can be obtained from the web, but for convenience they are contained in the repository and are actually automatically handled by the default build configuration:

• ScalaZ3 hosted on GitHub
• The libz3 library from microsoft

To build, type this:

$ xsbt clean
$ xsbt package # takes a while
$ xsbt script
$ source ./setupenv

Then you can try e.g.

$ ./leon ./testcases/sas2011-testcases/RedBlackTree.scala

and get something like this:

[ Info  ] . ┌─────────┐
          ╔═╡ Summary ╞═══════════════════════════════════════════════════════════════════════╗
          ║ └─────────┘                                                                       ║
          ║ add                       postcond.           valid               Z3-f+t    0.314 ║
          ║ add                       precond.    (82,14) valid               Z3-f+t    0.020 ║
          ║ add                       precond.    (82,18) valid               Z3-f+t    0.005 ║
          ║ balance                   postcond.           valid               Z3-f+t    0.409 ║
          ║ balance                   match.      (91,19) valid               Z3-f+t    0.034 ║
          ║ blackHeight               match.      (51,39) valid               Z3-f+t    0.004 ║
          ║ buggyAdd                  postcond.           invalid             Z3-f+t    4.084 ║
          ║ buggyAdd                  precond.     (87,8) invalid             Z3-f+t    0.111 ║
          ║ buggyBalance              postcond.           invalid             Z3-f+t    0.055 ║
          ║ buggyBalance              match.     (105,19) invalid             Z3-f+t    0.007 ║
          ║ ins                       postcond.           valid               Z3-f+t    6.577 ║
          ║ ins                       precond.    (63,40) valid               Z3-f+t    0.021 ║
          ║ ins                       precond.    (65,43) valid               Z3-f+t    0.005 ║
          ║ makeBlack                 postcond.           valid               Z3-f+t    0.007 ║
          ║ redNodesHaveBlackChildren match.      (35,56) valid               Z3-f+t    0.003 ║
          ║ size                      postcond.           valid               Z3-f+t    0.012 ║
          ╚═══════════════════════════════════════════════════════════════════════════════════╝

Building Leon

Leon requires quite a few dependencies, and you will need to make sure everything is correctly set up before being able to build it. Leon is probably much easier to build on Unix-like plattforms. Not to say it is impossible to build on Windows. But some scripts used to run and test the system are shell script and you will need to manually port them to Windows if you wish to use Windows.

First you need a Java Runtime Environment. The most recent version should work. Simply follow the standard installation process (e.g. apt-get) for your system.

Next, you need the Simple Build Tool (sbt) which seems to be (as of today) the standard way to build Scala program. Again you should follow the installation procedure. You can also find information about sbt here. Sbt is quite a complex tool, so I would suggest looking at the getting started guide on the wiki page. However, if you just want to quickly build Leon and never look back, then the information provided here should be sufficient.

(This section is outdated for linux, but can be useful to adapt on Windows/Mac) Now you will have to build the ScalaZ3 project. You should follow the instructions given in the ScalaZ3 project. The ScalaZ3 is a Scala wrapper on the Z3 native library from Microsoft. It is used in Leon to make native call to Z3. The generated .jar from ScalaZ3 will be dependent on your own z3 native library, which you can obtain from here. However, the ScalaZ3 repository comes with 32 and 64 bits version for Linux and you should probably use those ones to make sure the version is compatible. You can install the Z3 native library in some standard system library path such as /usr/lib. You need to install the scalaz3.jar file in the "unmanaged" directory. The build system is configured to use any jar file in the "unmanaged" directory. Finally be aware that the Z3 library will come with its own set of dependencies, in particular you will need to have GMP. You will probably have to fight with a few errors before everything can finally work together.

Finally you can build Leon. Start sbt from a terminal to get an interactive sbt session. Then type:

clean

This will make sure the build is clean, then:

package

This will compile everything and create jar files. This could take a long time. Finally you need to generate a running script with the command:

script

This will generate the leon script that can be used to run leon from command line with correct arguments and classpath. This script you should not need to re-generate another time, if you modify some code you just need to run compile again. If anything goes wrong, you should carefully read the error message and try to fix it. You can refer to the troubleshooting section of this manual.

Note that Leon is organised as a structure of two projects, with one main (or root) project and one sub-project. From a user point of view, this should most of the time be transparent and the build command should take care of everything. The subproject is in 'library' and contains required code to make Leon input programs valid Scala programs. The point of having this library sub-project, is that you can use the generated jar for the library sub-project on its own and you should be able to compile Leon testcases with the standard Scala compiler.

Now we can make sure that the build went fine. There is a collection of testcase in 'regression' that are used to check the correctness of the system. We provide a shell script run-tests.sh to run all of them and make sure Leon behaves as expected. You should run ./run-tests now to make sure everything is in order. Note that running all tests can take some time.

Using Leon

Layout of this directory

Here is a quick overview of the conventions used in the layout of this directory:

• src - Contains all Scala sources for the Leon project. The layout of the sources follows the standard SBT (and Maven) convention.

• regression - Contains many small testcases. They are meant to be run automatically with a test script and Leon should behave correctly on all of them (correctly could mean either proving validity, finding counter-example or refusing the input).

• testcases - Contains somewhat realistic testcases, that correspond to existing algorithms. Leon might not successfully handle all of them.

• README(.md) - This README file.

• PERMISSION - You can safely ignore this file. It is used to handle git PERMISSION for this repository.

• build.sbt

• project/Build.sbt - Configuration of SBT.

• library - Sub-project containing the Leon library. Needed if one wishes to run Leon testcases with standard Scala.

• unmanaged - This is the directory used by the build system to find unmanated dependencies. You usually need to manually add files to this directory.

• lib-bin and lib64-bin - Contains some binary dependencies for the system that have been build for different plattform/OS.

Troubleshooting

Sorry, not done yet :(