veikkoeeva / fstar

An ML-like language with a type system for program verification

FStar

An ML-like language with a type system for program verification

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This note describes the general structure of the F* verifier and its code.

Files:

README.txt: This file

setenv.sh:

A utility script that sets up the user's environment for running F*.

LICENSE-fsharp.txt:

The Apache 2.0 license of F# reproduced verbatim here. Of the
~20,000 lines of source code included here, a total of 1,330 lines
of source code were derived from F#. The rest was written from
scratch, primarily by N. Swamy. This is documented in further
detail below.

Directories:

bin/

 Contains various binary files that the verifier uses. 

 It includes binaries for the FSharp.PowerPack, various
 utilities that the verifier uses internally. 

 All these binaries are available separately. 

 In order to use F*, you will need to separately download Z3
 binaries and place them in this directory. You can fetch these
 binaries from z3.codeplex.com.

examples/

 Around 22k lines of sample F* code, organized into various
 directories. All of these examples are provided as part of the
 the release so that our users have guidance on how to use the F*
 tool. 

lib/

 Contains just two sample source files which are config files for
 the F* verifier.

src/

 All source code for the implementation of F* itself. 

 Makefile: A top-level file for building the verifier from source
           using the command line.
 
 fstar.fsproj: A project file for building the verifier using
               Visual Studio.
 

 fstar.fs: The top-level file in the source tree that launches the
           verification tool.

 basic/

    A directory containing various basic utilities used throughout
    the project.

    The following files, were adapted from the Apache 2.0 release
    of F#. Each of these files quotes F#'s license at the header.

    bytes.fs (derived from fsharp/src/absil/bytes.fs)
    range.fs (derived from fsharp/src/fsharp/range.fs)


 absyn/

    A directory definition various operations over the abstract
    syntax of F* programs. 


 parser/

    A directory defining a parser for F* concrete syntax into its
    abstract syntax. 

    The following files, were adapted from the Apache 2.0 release
    of F#. Each of these files quotes F#'s license at the header.

    lex.fsl (derived from fsharp/src/fsharp/lex.fsl)
    lexhelp.fs (derived from fsharp/src/fsharp/lexhelp.fs)

 tccore/
 
    Various utilities to operate over F* types and type environments.


 monadic/
 
    The main verification condition generator for F*. This is the
    module that derives a logical specification for an F* program. 


 z3encode/
 
    A module that translates F*'s logical specification into the
    input language of Z3. Once this translation is done, it calls
    into the Z3 binaries (provided in /bin) to verify that the
    logical spec is valid.