Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[0.49.0] - 2021-11-12

Added

• Support for solc 0.8.10

Changed

• Clearer display for the invalid opcode (0xfe) in debug view
• Better error messages when trying to deploy unlinked bytecode
• bytesX arguments to hevm abiencode are automatically padded

Fixed

• Test contracts with no code (e.g. abstract contracts) are now skipped
• Replay data for invariant tests is now displayed in a form that does not cause errors when used with dapp test --replay

[0.48.1] - 2021-09-08

Added

• Support for 0.8.4 custom error types in stack traces

Changed

• Contract feching happens synchronously again.
• Invariants checked before calling methods from targetContracts.

Fixed

• The block gas limit and basefee are now correctly fetched when running tests via rpc

0.48.0 - 2021-08-03

Changed

• Updated to London hard fork!
• The configuration variable DAPP_TEST_BALANCE_CREATE has been renamed to DAPP_TEST_BALANCE
• Default smttimeout has been increased to 1 minute.
• A new flag has been added to hevm (--ask-smt-iterations) that controls the number of iterations at which the symbolic execution engine will stop eager evaluation and begin to query the smt solver whether a given branch is reachable or not.
• Contract fetching now happens asynchronously.
• Fixed no contract definition crashes
• Removed NoSuchContract failures

0.47.0 - 2021-07-01

Added

• A new test runner for checking invariants against random reachable contract states.
• hevm symbolic can search for solc 0.8 style assertion violations, and a new --assertions flag has been added allowing users to customize which assertions should be reported
• A new cheatcode ffi(string[]) that executes an arbitrary command in the system shell

Changed

• Z3 is once again the default smt solver
• Updated nixpkgs to the 21.05 channel

Fixed

• Sourcemaps for contracts containing immutable are now shown in the debug view.

0.46.0 - 2021-04-29

Added

• Updated to Berlin! Conformant with GeneralStateTests at commit hash 644967e345bbc6642fab613e1b1737abbe131f78.

Fixed

• ADDMOD and MULMOD by zero yields zero.
• Address calculation for newly created contracts.
• Accomodated for the notorious "anomolies on the main network" (see yellow paper Appendix K for trivia)
• A hevm crash when debugging a SELFDESTRUCT contract.

0.45.0 - 2021-03-22

Added

• Two new cheatcodes were added: sign(uint sk, bytes message) and addr(uint sk). Taken together these should allow for much more ergonomic testing of code that handles signed messages.
• Symbolic execution can deal with partially symbolic bytecode, allowing for symbolic constructor arguments to be given in tests.

Fixed

• Fixed a bug in the abiencoding.
• Fixed the range being generated by ints.
• hevm flatten combines the SPDX license identifiers of all source files.

Changed

• updated nixpkgs to the 20.09 channel
• Arbitrary instance of AbiType can no longer generate a tuple

0.44.1 - 2020-02-02

Changed

• hevm cheatcodes now accept symbolic arguments, allowing e.g. symbolic jumps in time in unit tests
• More efficient arithmetic overflow checks by translating queries to a more intelligent form.

0.44.0 - 2020-01-26

Added

• hevm now accepts solidity json output built via --standard-json as well as --combined-json.
• addresses in the trace output are prefixed with ContractName@0x... if there is a corresponding contract and @0x... otherwise.

Fixed

• Symbolic execution now generates calldata arguments restricted to the proper ranges, following the semantics of fuzzing.
• If the --address flag is present in hevm exec or hevm symbolic, it overrides the contract address at which a contract will be created.
• Address pretty printing
• Updated sbv to 8.9.5 to fix "non-const in array declaration" cvc4 issue with ds-test.

Changed

• Use cvc4 as default smt solver

0.43.2 - 2020-12-10

Changed

• The default smttimeout has been increased from 20s to 30s

0.43.1 - 2020-12-10

Changed

• Counterexamples from symbolic tests now show clearer failure reasons

Fixed

• Symbolic tests now work with RPC
• Branch selection is working again in the interactive debugger

0.43.0 - 2020-11-29

Added

• A --show-tree option to hevm symbolic which prints the execution tree explored.
• Some symbolic terms are displayed with richer semantic information, instead of the black box <symbolic>.
• hevm dapp-test now supports symbolic execution of test methods that are prefixed with prove or proveFail
• The hevm interactive alias has been removed, as it is equivalent to hevm dapp-test --debug
• hevm dapp-test --match now matches on contract name and file path, as well as test name
• Step through the callstack in debug mode using the arrow keys

Changed

• dapp-test trace output now detects ds-note events and shows LogNote
• create addresses are shown with @<address> in the trace
• DSTest.setUp() is only run if it exists, rather than failing
• support new ds-test log_named_x(string, x) (previously bytes32 keys)
• return arguments are fully displayed in the trace (previously only a single word)
• return/revert trace will now show the correct source position

0.42.0 - 2020-10-31

Changed

• z3 updated to 4.8.8
• optimize SMT queries
• More useful trace output for unknown calls
• Default to on chain values for coinbase, timestamp, difficulty, blocknumber when rpc is provided
• Perform tx initialization (gas payment, value transfer) in hevm exec, hevm symbolic and hevm dapp-test.

Added

• TTY commands P and c-p for taking larger steps backwards in the debuger.
• --cache flag for dapp-test, exec, symbolic, interactive, enabling caching of contracts received by rpc.
• load(address,bytes32) cheat code allowing storage reads from arbitrary contracts.

0.41.0 - 2020-08-19

Changed

• Switched to PVP for version control, starting now at 0.41.0 (MAJOR.MAJOR.MINOR).
• z3 updated to 4.8.7
• Generate more interesting values in property based testing, and implement proper shrinking for all abi values.
• Fixed soundness bug when using KECCAK or SHA256 opcode/precompile
• Fixed an issue in debug mode where backstepping could cause path information to be forgotten
• Ensure that pathconditions are consistent when branching, and end the execution with VMFailure: DeadPath if this is not the case
• Fixed a soundness bug where nonzero jumpconditions were assumed to equal one.
• default --smttimeout changed from unlimited to 20 seconds
• hevm symbolic --debug now respects --max-iterations

Added

• hevm exec --trace flag to dump a trace
• Faster backstepping in interactive mode by saving multiple snapshot states.
• Support for symbolic storage for multiple contracts

0.40 - 2020-07-22

• hevm is now capable of symbolic execution!

Changed

As a result, the types of several registers of the EVM have changed to admit symbolic values as well as concrete ones.

• state.stack: Word -> SymWord.

• state.memory: ByteString -> [SWord 8].

• state.callvalue: W256 -> SymWord.

• state.caller: Addr -> SAddr.

• state.returndata: ByteString -> [SWord 8].

• state.calldata: ByteString -> ([SWord 8], (SWord 32)). The first element is a list of symbolic bytes, the second is the length of calldata. We have fst calldata !! i .== 0 for all snd calldata < i.

• tx.value: W256 -> SymWord.

• contract.storage: Map Word Word -> Storage, defined as:

data Storage
  = Concrete (Map Word SymWord)
  | Symbolic (SArray (WordN 256) (WordN 256))
  deriving (Show)

Added

New cli commands:

• hevm symbolic: search for assertion violations, or step through a symbolic execution in debug mode.
• hevm equivalence: compare two programs for equivalence.

See the README for details on usage.

The new module EVM.SymExec exposes several library functions dealing with symbolic execution. In particular,

• SymExec.interpret: implements an operational monad script similar to TTY.interpret and Stepper.interpret, but returns a list of final VM states rather than a single VM.
• SymExec.verify: takes a prestate and a postcondition, symbolically executes the prestate and checks that all final states matches the postcondition.

Removed

The concrete versions of a lot of arithmetic operations, replaced with their more general symbolic counterpart.

0.39 - 2020-07-13

• Exposes abi encoding to cli
• Added cheat code hevm.store(address a, bytes32 location, bytes32 value)
• Removes ExecMode, always running as ExecuteAsBlockchainTest. This means that hevm exec now finalizes transactions as well.
• --code is now entirely optional. Not supplying it returns an empty contract, or whatever is stored in --state.

0.38 - 2020-04-23

• Exposes metadata stripping of bytecode to the cli: hevm strip-metadata --code X. 357.
• Fixes a bug in the srcmap parsing introduced in 0.37 356.
• Fixes a bug in the abi-encoding of bytes with size > 32358.

0.37 - 2020-03-24

• Sourcemap parser now admits solc-0.6.0 compiled .sol.json files.

0.36 - 2020-01-07

• Implement Istanbul support 318
• Fix a bug introduced in 280 of rlp encoding of transactions and sender address 320.
• Make InvalidTx a fatal error for vm tests and ci.
• Suport property based testing in unit tests. 313 Arguments to test functions are randomly generated based on the function abi. Fuzz tests are not present in the graphical debugger.
• Added flags --replay and --fuzz-run to hevm dapp-test, allowing for particular fuzz run cases to be rerun, or for configuration of how many fuzz tests are run.
• Correct gas readouts for unit tests
• Prevent crash when trying to jump to next source code point if source code is missing

0.35 - 2019-11-02

• Merkle Patricia trie support 280
• RLP encoding and decoding functions 280
• Extended support for Solidity ABI encoding 259
• Bug fixes surrounding unit tests and gas accounting (https://github.com/dapphub/dapptools/commit/574ef401d3e744f2dcf994da056810cf69ef84fe, https://github.com/dapphub/dapptools/commit/5257574dd9df14edc29410786b75e9fb9c59069f)

0.34 - 2019-08-28

• handle new solc bzzr metadata in codehash for source map
• show VM hex outputs as hexadecimal
• rpc defaults to latest block
• hevm interactive:
• fix rpc fetch
• scrollable memory pane
• Fix regression in VMTest compliance.
• hevm exec ergonomics:
• Allow code/calldata prefixed with 0x
• create transactions with specific caller nonce
• interactive help pane
• memory pane scrolling

0.33 - 2019-08-06

• Full compliance with the General State Tests (with the BlockchainTest format), using the Yellow and Jello papers as reference, for Constantinople Fix (aka Petersburg). Including:
• full precompile support
• correct substate accounting, including touched accounts, selfdestructs and refunds
• memory read/write semantics
• many gas cost corrections
• Show more information for non solc bytecode in interactive view (trace and storage)
• Help text for all cli options
• Enable --debug flag in hevm dapp-test

0.32 - 2019-06-14

• Fix dapp-test nonce initialisation bug

0.31 - 2019-05-29

• Precompiles: SHA256, RIPEMD, IDENTITY, MODEXP, ECADD, ECMUL, ECPAIRING, MODEXP
• Show the hevm version with hevm version
• Interactive mode:
• no longer exits on reaching halt
• new shortcuts: 'a' / 'e' for start / end
• allow returning to test picker screen
• Exact integer formatting in dapp-test and tty

0.30 - 2019-05-09

• Adjustable verbosity level for dapp-test with --verbose={0,1,2}
• Working stack build

0.29 - 2019-04-03

• Significant jump in compliance with client tests
• Add support for running GeneralStateTests

0.28 - 2019-03-22

• Fix delegatecall gas metering, as reported in https://github.com/dapphub/dapptools/issues/34

0.27 - 2019-02-06

• Fix hevm flatten issue related to SemVer ranges in Solidity version pragmas

0.26 - 2019-02-05

• Format Solidity Error(string) messages in trace

0.25 - 2019-02-04

• Add SHL, SHR and SAR opcodes

0.24 - 2019-01-23

• Fix STATICCALL for precompiled contracts
• Assume Solidity 0.5.2 in tests

0.23 - 2018-12-12

• Show passing test traces with --verbose flag

0.22 - 2018-11-13

• Simple memory view in TTY

0.21 - 2018-10-29

• Fix Hackage package by including C header files for ethjet

0.20 - 2018-10-27

• Parse constructor inputs from Solidity AST

0.19 - 2018-10-09

• Enable experimental 'cheat' address, allowing for modification of the EVM environment from within the tests. Currently just the block timestamp can be adjusted.

0.18 - 2018-10-09

• Fix duplicate address bug

0.17 - 2018-10-05

• Semigroup/Monoid fix

0.16 - 2018-09-19

• Move ethjet into hevm

[0.15] - 2018-05-09

• Fix SDIV/SMOD definitions for extreme case

[0.14.1] - 2018-04-17

• Improve PC display in TTY

[0.14] - 2018-03-08

• Implement STATICCALL

[0.13] - 2018-02-28

• Require specific block number for RPC debugging
• Implement RETURNDATACOPY and RETURNDATASIZE
• Fix bug where created contracts didn't get their balance

[0.12.3] - 2017-12-19

• More useful RPC debugging because we strip the entire BZZR metadata

[0.12.2] - 2017-12-17

• Experimental new ecrecover implementation via libethjet
• Correct error checking for setUp() invocations

[0.12.1] - 2017-11-28

• Test name regex matching via --match
• Fixed source map parsing bug when used with solc --optimize
• TTY: fix a padding-related display glitch

0.12 - 2017-11-14

• Use 13 different environment variables to control block parameters for unit testing, e.g. block number, timestamp, initial balance, etc.

  Full list:

  • DAPP_TEST_ADDRESS
  • DAPP_TEST_CALLER
  • DAPP_TEST_ORIGIN
  • DAPP_TEST_GAS_CREATE
  • DAPP_TEST_GAS_CALL
  • DAPP_TEST_BALANCE_CREATE
  • DAPP_TEST_BALANCE_CALL
  • DAPP_TEST_COINBASE
  • DAPP_TEST_NUMBER
  • DAPP_TEST_TIMESTAMP
  • DAPP_TEST_GAS_LIMIT
  • DAPP_TEST_GAS_PRICE
  • DAPP_TEST_DIFFICULTY

0.11.5 - 2017-11-14

• Use --state with --exec --debug

0.11.4 - 2017-11-12

• Fix bug when unit test contract has creations in constructor

0.11.3 - 2017-11-08

• Fix array support in ABI module

0.11.2 - 2017-11-04

• TTY: show a help bar with key bindings at the bottom

0.11.1 - 2017-11-02

• TTY: fix a display glitch
• TTY: improve display of ABI hashes on the stack

0.11 - 2017-10-31

• Add "hevm flatten" for Etherscan-ish source code concatenation
• Simplify code by removing concrete/symbolic machine abstraction

0.10.9 - 2017-10-23

• Fix bugs in ABI formatting

0.10.7 - 2017-10-19

• Fix library linking bug
• Fix gas consumption of DELEGATECALL
• Better error tracing
• Experimental "contract browser" (stupid list of addresses)

0.10.6 - 2017-10-19

• Enable library linking for unit tests and debugger
• Use the same default gas/balance values as ethrun

0.10.5 - 2017-10-17

• Better trace output including arguments and return values
• Proof of concept coverage analysis via dapp-test --coverage

0.10 - 2017-10-10

• Enable new trace output by default for failing tests
• Exit with failure code from test runner when tests fail
• More fixes to improve Ethereum test suite compliance

0.9.5 - 2017-10-06

• Prototype of new trace output with hevm dapp-test --verbose
• Nicer trace tree in the TTY debugger
• Many fixes to improve Ethereum test suite compliance

0.9 - 2017-09-29

• Integrates with live chains via RPC (read-only)
• Exposes a special contract address with test-related functionality (time warp)

0.8.5 - 2017-09-22

• Renames hevm from its maiden name hsevm ✨

0.8 - 2017-09-21

• Implements gas metering (Metropolis rules by default)
• Shows gas counter in the terminal interface
• Enables debugger for consensus test executions
• Consensus test runner script with HTML reporting
• Passes 564 of the VMTests; fails 115 (see 0.8 test report)
• Command line options for specifying initial gas amounts and balances
• Improved TTY UI layout

0.7 - 2017-09-07

• Can save and load contract states to disk using a Git-backed store (only --exec)
• Can debug raw EVM bytecode using exec --debug
• Fixes exec --value
• Has smarter defaults for command line when running tests or debugging
• Fixes bug with MSIZE in CALL context

0.6.5 - 2017-09-01

• Fixes exec with regards to exit codes and error messages

0.6.1 - 2017-08-03

• TTY: Adds command C-n in TTY for "stepping over"

0.6 - 2017-08-03

• TTY: Adds second line to stack entries with humanized formatting
• TTY: Gets rid of the separate log pane in favor of a unified trace pane

0.5 - 2017-08-02

• TTY: Adds p command for stepping backwards
• Adds ability to track origins of stack and heap words
• Tracks Keccak preimage for words that come from the SHA3 instruction

0.4 - 2017-07-31

• Parallelizes unit test runner
• Improves speed by changing representation of memory
• Internal refactoring for future support of symbolic execution
• Adds logs to the trace pane

0.3.2 - 2017-06-17

• Adds REVERT opcode
• Sets TIMESTAMP value to 1 in unit tests

0.3.0 - 2017-06-14

• Reverts contract state after CALL fails
• Improves test runner console output

0.2.0 - 2017-06-13

• Fixes bug in CALL

0.1.0.1 - 2017-03-31

• Highlights Solidity exactly on character level
• Adds N command for stepping by Solidity source position instead of by opcode

0.1.0.0 - 2017-03-29

• First release