https://github.com/akupila/go-wasm

WebAssembly binary file parser written in go
https://github.com/akupila/go-wasm

binary go golang parser wasm

Last synced: about 2 months ago
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WebAssembly binary file parser written in go

• Host: GitHub
• URL: https://github.com/akupila/go-wasm
• Owner: akupila
• License: mit
• Created: 2018-07-24T09:35:43.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2021-10-30T16:01:06.000Z (about 3 years ago)
• Last Synced: 2024-11-07T04:39:59.942Z (about 2 months ago)
• Topics: binary, go, golang, parser, wasm
• Language: Go
• Homepage:
• Size: 1.26 MB
• Stars: 132
• Watchers: 4
• Forks: 11
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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# go-wasm

A WebAssembly binary file parser in go.

The parser takes an `io.Reader` and parses a WebAssembly module from it, which

allows the user to see into the binary file. All data is read, future version

may allow to write it out too, which would allow modifying the binary.

For example:

```go

package main

import (

	"flag"

	"fmt"

	"os"

	"text/tabwriter"

	wasm "github.com/akupila/go-wasm"

)

func main() {

	file := flag.String("file", "", "file to parse (.wasm)")

	flag.Parse()

	if *file == "" {

		flag.Usage()

		os.Exit(2)

	}

	f, err := os.Open(*file)

	if err != nil {

		fmt.Fprintf(os.Stderr, "open file: %v", err)

		os.Exit(1)

	}

	defer f.Close()

	mod, err := wasm.Parse(f)

	if err != nil {

		fmt.Fprintln(os.Stderr, err)

		os.Exit(1)

	}

	w := tabwriter.NewWriter(os.Stdout, 0, 0, 4, ' ', 0)

	fmt.Fprintf(w, "Index\tName\tSize (bytes)\n")

	for i, s := range mod.Sections {

		fmt.Fprintf(w, "%d\t%s\t%d\n", i, s.Name(), s.Size())

	}

	w.Flush()

}

```

_when passed in a `.wasm` file compiled with go1.11:_

```

Index    Name        Size (bytes)

0        Custom      103

1        Type        58

2        Import      363

3        Function    1588

4        Table       5

5        Memory      5

6        Global      51

7        Export      14

8        Element     3066

9        Code        1174891

10       Data        1169054

11       Custom      45428

```

**Much** more information is available by type asserting on the items in

`.Sections`, for example:

```go

for i, s := range mod.Sections {

    switch section := s.(type) {

        case *wasm.SectionCode:

            // can now read function bytecode from section.

    }

}

```

## Installation

```

go get github.com/akupila/go-wasm/...

```

## Notes

This is a experimental, early and definitely not properly tested. There are

probably bugs. If you find one, please open an issue!