Struct wasmparser::Parser

pub struct Parser<'a> { /* fields omitted */ }

The Parser type. A simple event-driven parser of WebAssembly binary format. The read(&mut self) is used to iterate through WebAssembly records.

Implementations

impl<'a> Parser<'a>

pub fn new(data: &[u8]) -> Parser

Constructs Parser type.

Examples

let data: &[u8] = &[0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00,
    0x01, 0x4, 0x01, 0x60, 0x00, 0x00, 0x03, 0x02, 0x01, 0x00,
    0x0a, 0x05, 0x01, 0x03, 0x00, 0x01, 0x0b];
let mut parser = wasmparser::Parser::new(data);

pub fn eof(&self) -> bool

pub fn current_position(&self) -> usize

Trait Implementations

impl<'a> WasmDecoder<'a> for Parser<'a>

fn read(&mut self) -> &ParserState<'a>

Reads next record from the WebAssembly binary data. The methods returns reference to current state of the parser. See ParserState num.

Examples

use wasmparser::WasmDecoder;
let mut parser = wasmparser::Parser::new(data);
{
    let state = parser.read();
    println!("First state {:?}", state);
}
{
    let state = parser.read();
    println!("Second state {:?}", state);
}

fn push_input(&mut self, input: ParserInput)

fn create_binary_reader<'b>(&mut self) -> BinaryReader<'b> where
    'a: 'b, 

Creates a BinaryReader when current state is ParserState::BeginSection or ParserState::BeginFunctionBody.

Examples

use wasmparser::{WasmDecoder, Parser, ParserState};
let mut parser = Parser::new(data);
let mut types = Vec::new();
let mut function_types = Vec::new();
let mut function_readers = Vec::new();
loop {
    match parser.read() {
        ParserState::Error(_) |
        ParserState::EndWasm => break,
        ParserState::TypeSectionEntry(ty) => {
            types.push(ty.clone());
        }
        ParserState::FunctionSectionEntry(id) => {
            function_types.push(id.clone());
        }
        ParserState::BeginFunctionBody {..} => {
            let reader = parser.create_binary_reader();
            function_readers.push(reader);
        }
        _ => continue
    }
}
for (i, reader) in function_readers.iter_mut().enumerate() {
    // Access the function type through the types table.
    let ty = &types[function_types[i] as usize];
    println!("\nFunction {} of type {:?}", i, ty);
    // Read the local declarations required by the function body.
    let local_decls_len = reader.read_local_count().unwrap();
    let mut local_decls = Vec::with_capacity(local_decls_len);
    let mut local_count = ty.params.len();
    for _ in 0..local_decls_len {
        let local_decl = reader.read_local_decl(&mut local_count).unwrap();
        local_decls.push(local_decl);
    }
    println!("Function locals: vars {:?}; total {} ", local_decls, local_count);
    // Read the operations of the function body.
    while let Ok(ref op) = reader.read_operator() {
        println!("  {:?}", op);
    }
}

fn read_with_input(&mut self, input: ParserInput) -> &ParserState<'a>

Reads next record from the WebAssembly binary data. It also allows to control how parser will treat the next record(s). The method accepts the ParserInput parameter that allows e.g. to skip section or function operators. The methods returns reference to current state of the parser.

Examples

use wasmparser::WasmDecoder;
let mut parser = wasmparser::Parser::new(data);
let mut next_input = wasmparser::ParserInput::Default;
loop {
    let state = parser.read_with_input(next_input);
    match *state {
        wasmparser::ParserState::EndWasm => break,
        wasmparser::ParserState::BeginWasm { .. } |
        wasmparser::ParserState::EndSection =>
            next_input = wasmparser::ParserInput::Default,
        wasmparser::ParserState::BeginSection { ref code, .. } => {
            println!("Found section: {:?}", code);
            next_input = wasmparser::ParserInput::SkipSection;
        },
        _ => unreachable!()
    }
}

fn last_state(&self) -> &ParserState<'a>