In this repository we provide a model of the EVM in K.

These may be useful for learning KEVM and K (newest to oldest):

• Jello Paper, generated using Sphinx Documentation Generation.
• 20 minute tour of the semantics at 2017 Devcon3.
• KEVM 1.0 technical report, especially sections 3 and 5.
• KEVM Paper at CSF'18/FLoC.

To get support for KEVM, please join our Riot Room.

There are four backends of K available, the OCAML and (experimental) LLVM backends for concrete execution, and the Java and (experimental) Haskell backends for symbolic reasoning and proofs. This repository generates the build-products for both non-experimental backends in .build/java/ and .build/ocaml/.

The following are needed for building/running KEVM:

• git
• Pandoc >= 1.17 is used to generate the *.k files from the *.md files.
• GNU Bison, Flex, and Autoconf.
• GNU libmpfr and libtool.
• Java 8 JDK (eg. OpenJDK)
• Opam, important: Ubuntu users prior to 15.04 must build from source, as the Ubuntu install for 14.10 and prior is broken. opam repository also requires rsync.

On Ubuntu >= 18.04 (for example):

sudo apt install                                             \
    autoconf bison flex gcc git libmpfr-dev libsecp256k1-dev \
    libtool libz3-dev make maven opam openjdk-8-jdk pandoc   \
    pkg-config z3 zlib1g-dev

On Ubuntu < 18.04, you'll need to skip libsecp256k1-dev and instead build it from source (via our Makefile):

make libsecp256k1

On ArchLinux:

sudo pacman -S                                              \
    base base-devel boost clang cmake crypto++ curl git gmp \
    jdk-openjdk jemalloc libsecp256k1 lld llvm maven mpfr   \
    opam python rustup stack yaml-cpp z3 zlib

On OSX, using Homebrew, after installing the command line tools package:

brew tap caskroom/cask
brew cask install adoptopenjdk8
brew install automake libtool gmp mpfr pkg-config pandoc maven opam z3 libffi
make libsecp256k1

NOTE: a previous version of these instructions required the user to run brew link flex --force. After fetching this revision, you should first run brew unlink flex, as it is no longer necessary and will cause an error if you have the homebrew version of flex installed instead of the xcode command line tools version.

After installing the above dependencies, make sure the submodules are setup:

git submodule update --init --recursive

If you haven't already setup K's OCaml dependencies more recently than February 1, 2019, then you also need to setup the K OCaml dependencies:

./.build/k/k-distribution/src/main/scripts/bin/k-configure-opam-dev

Finally, you can install repository specific dependencies and build the semantics:

make deps
make build

The K LLVM/Haskell backends, currently under development, require extra dependencies to work.

• Haskell Stack. Note that the version of the stack tool provided by your package manager might not be recent enough. Please follow installation instructions from the Haskell Stack website linked above.

To upgrade stack (if needed):

stack upgrade
export PATH=$HOME/.local/bin:$PATH

The LLVM backend has additional dependencies:

sudo apt install cmake clang-6.0 clang++-6.0 llvm-6.0 lld-6.0 libboost-test-dev libgmp-dev libyaml-cpp-dev libjemalloc-dev curl protobuf-compiler libprotobuf-dev

On Arch, you'll also need crypto++ package.

And you need to setup Rust:

.build/k/llvm-backend/src/main/native/llvm-backend/install-rust

Additionally, you need to setup the remaining LLVM dependencies.

On Ubuntu:

make llvm-deps

On Arch:

make LIBFF_CC=clang LIBFF_CXX=clang++ llvm-deps

After installing the above dependencies, the following command will build the extra backends into K:

• make haskell-deps: additionally build the Haskell backend into K.
• make llvm-deps: additionally build the LLVM backend into K.
• make all-deps: additionally build both the Haskell and LLVM backends into K.

Following this dependency setup, you can also now kompile the LLVM and Haskell backends:

make build-haskell
make build-llvm

The following files constitute the KEVM semantics:

• krypto.md sets up some basic cryptographic primitives.
• data.md provides the (functional) data of EVM (256 bit words, wordstacks, etc...).
• evm.md is the main KEVM semantics, containing the configuration and transition rules of EVM.

These additional files extend the semantics to make the repository more useful:

• driver.md is an execution harness for KEVM, providing a simple language for describing tests/programs.
• edsl.md defines high-level notations of eDSL, a domain-specific language for EVM specifications, for formal verification of EVM bytecode using K Reachability Logic Prover.

After building the definition, you can run the definition using ./kevm. Read the ./kevm script for examples of the actual invocations of krun that ./kevm makes.

Run the file tests/ethereum-tests/VMTests/vmArithmeticTest/add0.json:

./kevm run tests/ethereum-tests/VMTests/vmArithmeticTest/add0.json

Run the same file as a test:

./kevm test tests/ethereum-tests/VMTests/vmArithmeticTest/add0.json

To run proofs, you can similarly use ./kevm. For example, to prove the specification tests/proofs/specs/vyper-erc20/totalSupply-spec.k:

./kevm prove tests/proofs/specs/vyper-erc20/totalSupply-spec.k

The tests are run using the supplied Makefile. First, run make split-tests to generate some of the tests from the markdown files.

The following subsume all other tests:

• make test: All of the quick tests.
• make test-all: All of the quick and slow tests.

These are the individual test-suites (all of these can be suffixed with -all to also run slow tests):

• make test-vm: VMTests from the Ethereum Test Set.
• make test-bchain: Subset of BlockchainTests from the Ethereum Test Set.
• make test-proof: Proofs from the Verified Smart Contracts.
• make test-interactive: Tests of the ./kevm command.

When running tests with the Makefile, you can specify the TEST_CONCRETE_BACKEND (for concrete tests), or TEST_SYMBOLIC_BACKEND (for proofs).

This repository can build two pieces of documentation for you, the Jello Paper and the 2017 Devcon3 presentation.

If you also want to build the Jello Paper, you'll additionally need:

• Sphinx Documentation Generation tool, and
• The K Editor Support Python pygments package.

sudo apt install python-pygments python-sphinx python-recommonmark
git clone 'https://github.com/kframework/k-editor-support'
cd k-editor-support/pygments
easy_install --user .

For the 2017 Devcon3 presentation, you'll need pdflatex, commonly provided with texlive-full.

sudo apt install texlive-full

The Makefile supplies targets for building:

• All media in this list: make media
• Jello Paper documentation: make sphinx
• 2017 Devcon3 presentation: make 2017-devcon3

• EVM Yellowpaper: Original specification of EVM.
• LEM Semantics of EVM

For more information about The K Framework, refer to these sources:

• The K Tutorial
• Semantics-Based Program Verifiers for All Languages
• Reachability Logic Resources
• Matching Logic Resources
• Logical Frameworks: Discussion of logical frameworks.