The paper

The extended version of the paper describing the EthVer compiler can be found in paper_extended.pdf file

The EthVer compiler

Requirements

In order to use EthVer, you need to install ghc, happy, alex and bnfc.

Quick start guide

To build EthVer, run:

./build.sh

To compile example contract, run ./MakeEthver on one of the .etv files from the example dir, e.g.

./MakeEthver examples/micro_v1.etv

As a result, EthVer will produce 3 files:

• micro_v1.sol --- a Solidity file with the code of the contract which can be deployed in Ethereum,
• micro_v1.scen --- a scenario file with web3.js commands to execute the contract,
• micro_v1.prism --- a file that can be opened in PRISM and verified against the properties from micro_v.prism.

The lexical structure of ETV

Identifiers

Identifiers Ident are unquoted strings beginning with a letter, followed by any combination of letters, digits, and the characters _ ' reserved words excluded.

Literals

String literals String have the form ``, where x is any sequence of any characters except `"` unless preceded by ``.

Integer literals Integer are nonempty sequences of digits.

Reserved words and symbols

The set of reserved words is the set of terminals appearing in the grammar. Those reserved words that consist of non-letter characters are called symbols, and they are treated in a different way from those that are similar to identifiers. The lexer follows rules familiar from languages like Haskell, C, and Java, including longest match and spacing conventions.

The reserved words used in ethver are the following:

address, bool, cash, cmt_uint, communication, constructor, contract, else, false, finney, function, hash, hashOf, if, mapping, nonce, payable, public, random, randomCmt, revealCmt, scenario, sendCommunication, sendTransaction, sign, signature, this, transfer, true, uint, user, value, valueOf, verCmt, verSig, wait, while

The symbols used in ethver are the following:

;, =, {, }, [, ], (, =>, ), ,, ., &&, ==, !=, <, <=, >, >=, +, -, *, /, %, !, msg.value, msg.sender

Comments

Single-line comments begin with //. Multiple-line comments are enclosed with /* and */.

The syntactic structure of ethver

Non-terminals are enclosed between < and >. The symbols -> (production), | (union) and eps (empty rule) belong to the BNF notation. All other symbols are terminals.

<Program>  ->  <[UserDecl]> <[ConstantDecl]> <Contract> <Communication> <[Scenario]>
<[UserDecl]>  ->  eps
     | <UserDecl> ; <[UserDecl]>
<[ConstantDecl]>  ->  eps
     | <ConstantDecl> ; <[ConstantDecl]>
<[Scenario]>  ->  eps
     | <Scenario> <[Scenario]>
<UserDecl>  ->  user <String>
<ConstantDecl>  ->  <Ident> = <Integer>
<Contract>  ->  contract <Ident> { <[Decl]> <Constructor> <[Function]> }
<Decl>  ->  <Type> <Ident>
     | <Type> <Ident> = <Exp>
     | <Type> <Ident> [ <Integer> ]
     | mapping ( address => <Type> ) <Ident>
<[Decl]>  ->  eps
     | <Decl> ; <[Decl]>
<[Function]>  ->  eps
     | <Function> <[Function]>
<Constructor>  ->  constructor ( ) { <[Stm]> }
<Communication>  ->  communication { <[Decl]> <[Function]> }
<Scenario>  ->  scenario <Ident> { <[Decl]> <[Stm]> }
<Function>  ->  function <Ident> ( <[Arg]> ) public { <[Stm]> }
     | function <Ident> ( <[Arg]> ) public payable { <[Stm]> }
<Arg>  ->  <Type> <Ident>
<[Arg]>  ->  eps
     | <Arg>
     | <Arg> , <[Arg]>
<Stm>  ->  { <[Stm]> }
     | <Ident> = <Exp> ;
     | <Ident> [ <Exp> ] = <Exp> ;
     | if ( <Exp> ) <Stm>
     | if ( <Exp> ) <Stm> else <Stm>
     | while ( <Exp> ) <Stm>
     | <Exp> . transfer ( <Exp> ) ;
     | <Exp> . sendTransaction ( <[CallArg]> ) ;
     | <Exp> . sendCommunication ( <[Exp]> ) ;
     | <Exp> . randomCmt ( ) ;
     | <Exp> . revealCmt ( ) ;
     | wait ( <Exp> , <Exp> ) ;
<[Stm]>  ->  eps
     | <Stm> <[Stm]>
<[Exp]>  ->  eps
     | <Exp>
     | <Exp> , <[Exp]>
<Exp>  ->  <Exp> || <Exp1>
     | <Exp1>
<Exp1>  ->  <Exp1> && <Exp2>
     | <Exp2>
<Exp2>  ->  <Exp2> == <Exp3>
     | <Exp2> != <Exp3>
     | <Exp3>
<Exp3>  ->  <Exp3> < <Exp4>
     | <Exp3> <= <Exp4>
     | <Exp3> > <Exp4>
     | <Exp3> >= <Exp4>
     | <Exp4>
<Exp4>  ->  <Exp4> + <Exp5>
     | <Exp4> - <Exp5>
     | <Exp5>
<Exp5>  ->  <Exp5> * <Exp6>
     | <Exp5> / <Exp6>
     | <Exp5> % <Exp6>
     | <Exp6>
<Exp6>  ->  - <Exp6>
     | ! <Exp6>
     | random ( <Exp6> )
     | sign ( <[Exp]> )
     | verSig ( <Exp> , <Exp> , ( <[Exp]> ) )
     | verCmt ( <Exp> , <Exp> )
     | finney ( <Integer> )
     | <Exp7>
<Exp7>  ->  <Ident> [ <Exp> ]
     | valueOf ( <Exp7> )
     | hashOf ( <Exp7> )
     | <Exp8>
<Exp8>  ->  msg.value
     | msg.sender
     | <Ident>
     | <String>
     | <Integer>
     | true
     | false
     | this
     | ( <Exp> )
<[CallArg]>  ->  eps
     | <CallArg>
     | <CallArg> , <[CallArg]>
<CallArg>  ->  <Exp>
     | { value : <Exp> }
<Type>  ->  uint ( <Integer> )
     | cash ( <Integer> )
     | bool
     | cmt_uint ( <Integer> )
     | signature ( <[Type]> )
     | address
     | nonce
     | hash
<[Type]>  ->  eps
     | <Type>
     | <Type> , <[Type]>