# WASMonkey

The WASMonkey patches a WASM object file to replace a set of exported
functions with imported functions from another library.

## Usage

```text
USAGE:
    wasmonkey [FLAGS] [OPTIONS] --input <input_file> --output <output_file>

FLAGS:
    -n, --original-names    Use the original name as a key in the builtins map
    -h, --help              Prints help information
    -V, --version           Prints version information

OPTIONS:
    -B, --builtins-additional <builtins_additional>...    Additional builtins function names to replace
    -b, --builtins <builtins_file>                        Path to the builtins library
    -m, --builtins-map <builtins_map_file>                Path to the builtins map file
    -i, --input <input_file>                              Path to the input file
    -o, --output <output_file>                            Path to the output file
```

`builtins_file` is an object containing alternative implementations to
functions called in the wasm code.

Symbols starting with a `builtin_` prefix will be used for substitution.

For example, a `memmove()` function defined as an external in the WASM
object will be replaced by calls to an imported `builtin_memmove()`
function, if `builtin_memmove()` is present in the builtins file.

A JSON-encoded map of the performed substitutions can be optionally written
into `builtins_map_file`.