# wasm-utils
[](https://travis-ci.org/paritytech/wasm-utils)
Collection of WASM utilities used in Parity and WASM contract development
## Build tools for cargo
Easiest way to use is to install via `cargo install`:
```
cargo install pwasm-utils-cli --bin wasm-build
```
## Symbols pruning (wasm-prune)
```
cargo install pwasm-utils-cli --bin wasm-prune
wasm-prune <input_wasm_binary.wasm> <output_wasm_binary.wasm>
```
This will optimize WASM symbols tree to leave only those elements that are used by contract `call` function entry.
## Gas counter (wasm-gas)
For development puposes, raw WASM contract can be injected with gas counters (the same way as it done by Parity runtime when running contracts)
```
cargo install pwasm-utils-cli --bin wasm-gas
wasm-gas <input_wasm_binary.wasm> <output_wasm_binary.wasm>
```
## Externalization (wasm-ext)
Parity WASM runtime provides some library functions that can be commonly found in libc. WASM binary size can be reduced and performance may be improved if these functions are used. This utility scans for invocations of the following functions inside the WASM binary:
- `_malloc`,
- `_free`,
- `_memcpy`,
- `_memset`,
- `_memmove`
And then substitutes them with invocations of the imported ones. Should be run before `wasm-opt` for better results.
```
cargo install pwasm-utils-cli --bin wasm-ext
wasm-ext <input_wasm_binary.wasm> <output_wasm_binary.wasm>
```
## API
All executables use corresponding api methods of the root crate and can be combined in other build tools.
# License
`wasm-utils` is primarily distributed under the terms of both the MIT
license and the Apache License (Version 2.0), at your choice.
See LICENSE-APACHE, and LICENSE-MIT for details.
## Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in `wasm-utils` by you, as defined in the Apache-2.0 license, shall be
dual licensed as above, without any additional terms or conditions.