wain-validate

wain-validate is a crate to validate a parsed WebAssembly abstract syntax tree. Validation logic is defined in spec

This crate is part of larger wain project.

Installation

toml [dependencies] wain-validate = "0"

It takes a reference to wain_ast::Root value and validates it. The value can be generated by wain-syntax-binary and wain-syntax-text parsers:

Using wain_validate::validate() is the easiest way.

```rust extern crate wainsyntaxbinary; extern crate wain_validate;

use std::fs; use wainsyntaxbinary::parse; use wain_validate::validate;

let source = fs::read("foo.wasm").unwrap(); let tree = parse(&source).unwrap();

if let Err(err) = validate(&tree) { eprintln!("This .wasm file is invalid!: {}", err); } ```

Working examples can be seen at examples/api/ directory

Please read documentation (not yet) for details.

Conforming spec, following things are validated:

In Wasm, every reference is an index. It validates all indices are not out of bounds
Wasm is designed to check stack operations statically. It validates instructions sequences with emulating stack state
Type check is best-effort due to polymorphic instruction select. Since almost all instructions are not polymorphic, almost all type checks can be done in validation

Conforming the spec, wain validates instructions after unreachable instruction. For example,

wat (unreachable) (i64.const 0) (i32.add)

i32.add is invalid because it should take two i32 values from stack but at least one i64 value is in the stack.