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
[]
= "0"
Usage
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.
extern crate wain_syntax_binary;
extern crate wain_validate;
use fs;
use parse;
use validate;
let source = read.unwrap;
let tree = parse.unwrap;
if let Err = validate
Working examples can be seen at examples/api/ directory
Please read documentation (not yet) for details.
Implementation
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,
(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.