CosmWasm VM

This is an abstraction layer around the wasmer VM to expose just what we need to run CosmWasm contracts in a high-level manner. This is intended both for efficient writing of unit tests, as well as a public API to run contracts in eg. wasmvm. As such it includes all glue code needed for typical actions, like fs caching.

Compatibility

A VM can support one or more contract-VM interface versions. The interface version is communicated by the contract via a Wasm import. This is the current compatibility list:

Changes between interface versions

interface_version_5 -> interface_version_6

• Rename the fields from send to funds in WasmMsg::Instantiate and WasmMsg::Execute.
• Merge messages and sub-messages.
• Change JSON representation of IBC acknowledgements (#975).

Setup

There are demo files in testdata/*.wasm. Those are compiled and optimized versions of contracts/* run through cosmwasm/optimizer.

To rebuild the test contracts, go to the repo root and do

docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="devcontract_cache_cyberpunk",target=/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  cosmwasm/optimizer:0.16.1 ./contracts/cyberpunk \
  && cp artifacts/cyberpunk.wasm packages/vm/testdata/cyberpunk.wasm

docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="devcontract_cache_hackatom",target=/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  cosmwasm/optimizer:0.16.1 ./contracts/hackatom \
  && cp artifacts/hackatom.wasm packages/vm/testdata/hackatom.wasm

docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="devcontract_cache_ibc_reflect",target=/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  cosmwasm/optimizer:0.16.1 ./contracts/ibc-reflect \
  && cp artifacts/ibc_reflect.wasm packages/vm/testdata/ibc_reflect.wasm

docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="devcontract_cache_empty",target=/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  cosmwasm/optimizer:0.16.1 ./contracts/empty \
  && cp artifacts/empty.wasm packages/vm/testdata/empty.wasm

docker run --rm -v "$(pwd)":/code \
  --mount type=volume,source="devcontract_cache_ibc_callback",target=/target \
  --mount type=volume,source=registry_cache,target=/usr/local/cargo/registry \
  cosmwasm/optimizer:0.16.1 ./contracts/ibc-callbacks \
  && cp artifacts/ibc_callbacks.wasm packages/vm/testdata/ibc_callbacks.wasm

The cyberpunk_rust170.wasm for https://github.com/CosmWasm/cosmwasm/issues/1727 is built as follows (non-reproducible):

cd contracts/cyberpunk
rm -r target
RUSTFLAGS='-C link-arg=-s' cargo build --release --lib --target wasm32-unknown-unknown --locked
cp target/wasm32-unknown-unknown/release/cyberpunk.wasm ../../packages/vm/testdata/cyberpunk_rust170.wasm

The floaty_2.0.wasm is built using Rust nightly as follows (non-reproducible):

cd contracts/floaty
RUSTFLAGS="-C link-arg=-s -C target-feature=+nontrapping-fptoint" cargo wasm
cp target/wasm32-unknown-unknown/release/floaty.wasm ../../packages/vm/testdata/floaty_2.0.wasm

Testing

By default, this repository is built and tested with the singlepass backend.

cd packages/vm
cargo test --features iterator

Benchmarking

cd packages/vm
cargo bench --no-default-features

Tools

module_size and module_size.sh

Memory profiling of compiled modules. module_size.sh executes module_size, and uses valgrind's memory profiling tool (massif) to compute the amount of heap memory used by a compiled module.

cd packages/vm
RUSTFLAGS="-g" cargo build --release --example module_size
./examples/module_size.sh ./testdata/hackatom.wasm

License

This package is part of the cosmwasm repository, licensed under the Apache License 2.0 (see NOTICE and LICENSE).