README.md

Compile source code to WASM

RUST

We have a sample wasm binary under: sample-wasm-chaincode/chaincode_example02/rust/app_main.wasm

• Install rust toolchain and wasm-pack. Official Setup guide here , or use these two commands:

  curl https://sh.rustup.rs -sSf | sh
  curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
  

• Create a Cargo.toml (sample) in root directory with this content:

  [package]
  name = "app_main"
  version = "0.1.0"
  authors = ["shubham aggarwal <ag.shubham94@gmail.com>"]
  edition = "2018"
  
  [lib]
  crate-type = ["cdylib"]
  
  [dependencies]
  wasm-bindgen = "0.2"
  

• Create a src folder and place lib.rs in source forlder. Your directory structure should look like this:

  .
  ├── Cargo.toml
  └── src
     └── lib.rs
  

• From root directory, give command wasm-pack build. It will take some time for first time to download all dependencies. Once done you will receive a similar message in console Your wasm pkg is ready to publish at ./pkg.
• If successful, the wasm binary can be located at pkg/app_main_bg.wasm

C

We have a sample wasm binary under: sample-wasm-chaincode/chaincode_example02/c/app_main.wasm

• Install clang8 and llvm Linux repository link
• To compile C file to wasm, issue following command

 clang \
   --target=wasm32 \
   -O3 \
   -flto \
   -nostdlib \
   -Wl,--no-entry \
   -Wl,--export-all \
   -Wl,--lto-O3 \
   -o app_main.wasm \
   main.c