5. Compilation, Installation¶
5.1. Installing Why3¶
5.1.1. Installation via Opam¶
The simplest way to install Why3 is via Opam, the OCaml package manager. It is as simple as
opam install why3
Then jump to Section 5.2 to install external provers.
5.1.2. Installation via Docker¶
Instead of compiling Why3, one can also execute a precompiled version (for amd64 architecture) using Docker. The image containing Why3 as well as a few provers can be recovered using
docker pull registry.gitlab.inria.fr/why3/why3:1.4.0 docker tag registry.gitlab.inria.fr/why3/why3:1.4.0 why3
Let us suppose that there is a file
foo.mlw in your current
directory. If you want to verify it using Z3, you can type
docker run --rm --volume `pwd`:/data --workdir /data why3 prove foo.mlw -P z3
If you want to verify
foo.mlw using the graphical user interface,
the invocation is slightly more complicated as the containerized
application needs to access your X server:
docker run --rm --network host --user `id -u` --volume $HOME/.Xauthority:/home/guest/.Xauthority --env DISPLAY=$DISPLAY --volume `pwd`:/data --workdir /data why3 ide foo.mlw
It certainly makes sense to turn this command line into a shell script for easier use:
#!/bin/sh exec docker run --rm --network host --user `id -u` --volume $HOME/.Xauthority:/home/guest/.Xauthority --env DISPLAY=$DISPLAY --volume `pwd`:/data --workdir /data why3 "$@"
It is also possible to run the graphical user interface from within a web
browser, thus alleviating the need for a X server. To do so, just set the
web and publish port 8080:
docker run --rm -p 8080:8080 --env WHY3IDE=web --user `id -u` --volume `pwd`:/data --workdir /data why3 ide foo.mlw
You can now point your web browser to http://localhost:8080/. As before, this can be turned into a shell script for easier use:
#!/bin/sh exec docker --rm -p 8080:8080 --env WHY3IDE=web --user `id -u` --volume `pwd`:/data --workdir /data why3 "$@"
5.1.3. Installation from Source Distribution¶
In short, installation from sources proceeds as follows.
./configure make make install
After unpacking the distribution, go to the newly created directory
why3-1.4. Compilation must start with a configuration phase which is
This analyzes your current configuration and checks if requirements hold. Compilation requires:
The Objective Caml compiler. It is available as a binary package for most Unix distributions. For Debian-based Linux distributions, you can install the packages
It is also installable from sources, downloadable from the site http://caml.inria.fr/ocaml/
For some of the Why3 tools, additional OCaml libraries are needed:
For the graphical interface, the Lablgtk2 library is needed. It provides OCaml bindings of the gtk2 graphical library. For Debian-based Linux distributions, you can install the packages
It is also installable from sources, available from the site http://wwwfun.kurims.kyoto-u.ac.jp/soft/olabl/lablgtk.html
If you want to use the Coq realizations (Section 11.2),
then Coq has to be installed before Why3. Look at the summary printed at
the end of the configuration script to check if Coq has been detected
properly. Similarly, in order to use PVS (Section 11.5) or Isabelle
(Section 11.4) to discharge proofs, PVS and Isabelle must be
installed before Why3. You should check that those proof assistants are
correctly detected by the
When configuration is finished, you can compile Why3.
Installation is performed (as super-user if needed) using
Installation can be tested as follows:
install some external provers (see Section 5.2 below)
run some examples from the distribution, e.g., you should obtain the following (provided the required provers are installed on your machine):
> cd examples > why3 replay logic/scottish-private-club 1/1 (replay OK) > why3 replay same_fringe 18/18 (replay OK)
220.127.116.11. Local Use, Without Installation¶
Installing Why3 is not mandatory. It can be configured in a way such that it can be used from its compilation directory:
./configure --enable-local make
The Why3 executable files are then available in the subdirectory
This directory can be added to your
18.104.22.168. Installation of the Why3 API¶
By default, the Why3 API is not installed. It can be installed using
make byte opt make install-lib
Beware that if your OCaml installation relies on Opam installed in your
own user space, then
make install-lib should not be run as
22.214.171.124. Removing Installation¶
Removing installation can be done using
make uninstall make uninstall-lib
5.2. Installing External Provers¶
Why3 can use a wide range of external theorem provers. These need to be installed separately, and then Why3 needs to be configured to use them. There is no need to install automatic provers, e.g., SMT solvers, before compiling and installing Why3. For installation of external provers, please refer to the specific section about provers from http://why3.lri.fr/. (If you have installed Why3 via Opam, note that you can install the SMT solver Alt-Ergo via Opam as well.)
Once you have installed a prover, or a new version of a prover, you have to run the following command:
It scans your
PATH for provers and updates your configuration file
(see Section 6.1) accordingly.
5.2.1. Multiple Versions of the Same Prover¶
Why3 is able to use several versions of the same prover, e.g., it can use both
CVC4 1.4 and CVC4 1.5 at the same time. The automatic detection of
provers looks for typical names for their executable command, e.g., cvc4
for CVC3. However, if you install several versions of the same prover it
is likely that you would use specialized executable names, such as
cvc4-1.4 or cvc4-1.5. If needed, the command
why3 config add-prover can be
used to specify names of prover executables:
why3 config add-prover CVC4 /usr/local/bin/cvc4-dev cvc4-dev
the first argument (here
CVC4) must be one of the known provers. The
list of these names can be obtained
why3 config list-supported-provers.
They can also be found in the file
typically located in
/usr/local/share/why3 after installation. See
Section 12.2 for details.
5.2.2. Session Update after Prover Upgrade¶
If you happen to upgrade a prover, e.g., installing CVC4 1.5 in place of CVC4 1.4, then the proof sessions formerly recorded will still refer to the old version of the prover. If you open one such a session with the GUI, and replay the proofs, a popup window will show up for asking you to choose between three options:
Keep the former proof attempts as they are, with the old prover version. They will not be replayed.
Remove the former proof attempts.
Upgrade the former proof attempts to an installed prover (typically an upgraded version). The corresponding proof attempts will become attached to this new prover, and marked as obsolete, to make their replay mandatory. If a proof attempt with this installed prover is already present the old proof attempt is just removed. Note that you need to invoke again the replay command to replay those proof attempts.
Copy the former proofs to an installed prover. This is a combination of the actions above: each proof attempt is duplicated, one with the former prover version, and one for the new version marked as obsolete.
Notice that if the prover under consideration is an interactive one, then the copy option will duplicate also the edited proof scripts, whereas the upgrade-without-copy option will just reuse the former proof scripts.
Your choice between the three options above will be recorded, one for each prover, in the Why3 configuration file. Within the GUI, you can discard these choices via thedialog: just click on one choice to remove it.
Outside the GUI, the prover upgrades are handled as follows. The
replay command will take into account any prover upgrade policy
stored in the configuration. The
session command performs move or
copy operations on proof attempts in a fine-grained way, using filters,
as detailed in Section 6.5.
5.3. Configure Editors for editing WhyML sources¶
The Why3 distributions come with some configuration files for Emacs and for Vim. These files are typically installed in the shared data directory, which is given by
The Why3 distributions come with a mode for Emacs in a file
why3.el. That file is typically found in sub-directory
emacs. Under OPAM, this file is installed in a shared
emacs/site-lisp for all OPAM packages. Here is a
sample Emacs-Lisp code that can be added to your
(setq why3-share (if (boundp 'why3-share) why3-share (ignore-errors (car (process-lines "why3" "--print-datadir"))))) (setq why3el (let ((f (expand-file-name "emacs/why3.elc" why3-share))) (if (file-readable-p f) f (let ((f (expand-file-name "emacs/site-lisp/why3.elc" opam-share))) (if (file-readable-p f) f nil))))) (when why3el (require 'why3) (autoload 'why3-mode why3el "Major mode for Why3." t) (setq auto-mode-alist (cons '("\\.mlw$" . why3-mode) auto-mode-alist)))
Some configuration files are present in the share data directory, under sub-directory
5.4. Configure Shells for auto-completion of Why3 command arguments¶
Some configuration files for shells are distributed in the shared data directory,
which is given by
There are configuration files for
The configuration for
bash can be made from Why3 sources using
sudo make install-bash
or directly doing
sudo /usr/bin/install -c `why3 --print-datadir`/bash/why3 /etc/bash_completion.d
5.5. Inference of Loop Invariants¶
This section shows how to install infer-loop, an utility based on abstract interpretation to infer loop invariants [Bau17]. This is still work in progress and many features are still very limited.
infer-loop utility has the following OCaml dependencies.
apron: can be installed using
camllib: can be installed using
fixpoint: follow instructions below.
camllib libraries can be installed using
fixpoint library is not available in
it can be easily compiled and installed using the source code. The
following commands are just an example of how the library can be
compiled and installed, and can be performed in any directory.
svn co svn://scm.gforge.inria.fr/svnroot/bjeannet/pkg/fixpoint cd fixpoint/trunk/ cp Makefile.config.model Makefile.config # if required make modifications to Makefile.config make all # compiles make install # uses ocamlfind to install the library
By default the infer-loop mechanism is not compiled and integrated
with Why3. So, once the dependencies above are installed, the
configuration script of Why3 should enable the compilation of the
infer-loop utility. This can be done by passing to the Why3
configure script the
--enable-infer flag, as follows:
./configure --enable-infer # ... # Components # ... # Invariant inference(exp): yes # ...
Invariant inference(exp) indicates whether the
dependencies are correctly installed and whether the flag mentioned
above was selected. After the compilation, the loop inference
mechanism should be available. See Section 8.5 for