twiggy-parser 0.3.0

//! Parses binaries into `twiggy_ir::Items`.

#![deny(missing_docs)]
#![deny(missing_debug_implementations)]

#[cfg(feature = "dwarf")]
extern crate fallible_iterator;
#[cfg(feature = "dwarf")]
extern crate gimli;
#[cfg(feature = "dwarf")]
extern crate object;
extern crate parity_wasm;
#[cfg(feature = "dwarf")]
extern crate typed_arena;

extern crate twiggy_ir as ir;
extern crate twiggy_traits as traits;

#[cfg(feature = "dwarf")]
mod object_parse;
mod wasm_parse;

use parity_wasm::elements;
use std::fs;
use std::io::Read;
use std::path;

/// Parse the file at the given path into IR items.
pub fn read_and_parse<P: AsRef<path::Path>>(path: P) -> Result<ir::Items, traits::Error> {
    let path = path.as_ref();
    let mut file = fs::File::open(path)?;
    let mut data = vec![];
    file.read_to_end(&mut data)?;

    match path.extension().and_then(|s| s.to_str()) {
        Some("wasm") => parse_wasm(&data),
        #[cfg(feature = "dwarf")]
        _ => parse_other(&data),
        #[cfg(not(feature = "dwarf"))]
        _ => parse_fallback(&data),
    }
}

/// Parse the given data into IR items.
pub fn parse(data: &[u8]) -> Result<ir::Items, traits::Error> {
    parse_fallback(data)
}

/// A trait for parsing things into `ir::Item`s.
pub(crate) trait Parse<'a> {
    /// Any extra data needed to parse this type's items.
    type ItemsExtra;

    /// Parse `Self` into one or more `ir::Item`s and add them to the builder.
    fn parse_items(
        &self,
        items: &mut ir::ItemsBuilder,
        extra: Self::ItemsExtra,
    ) -> Result<(), traits::Error>;

    /// Any extra data needed to parse this type's edges.
    type EdgesExtra;

    /// Parse edges between items. This is only called *after* we have already
    /// parsed items.
    fn parse_edges(
        &self,
        items: &mut ir::ItemsBuilder,
        extra: Self::EdgesExtra,
    ) -> Result<(), traits::Error>;
}

fn parse_wasm(data: &[u8]) -> Result<ir::Items, traits::Error> {
    let mut items = ir::ItemsBuilder::new(data.len() as u32);

    let module: elements::Module = elements::deserialize_buffer(data)?;

    // Greedily parse the name section, if it exists.
    let module = match module.parse_names() {
        Ok(m) | Err((_, m)) => m,
    };

    module.parse_items(&mut items, ())?;
    module.parse_edges(&mut items, ())?;

    Ok(items.finish())
}

#[cfg(feature = "dwarf")]
fn parse_other(data: &[u8]) -> Result<ir::Items, traits::Error> {
    let mut items = ir::ItemsBuilder::new(data.len() as u32);

    let file: object::File = object::File::parse(data)?;

    file.parse_items(&mut items, ())?;
    file.parse_edges(&mut items, ())?;

    Ok(items.finish())
}

fn parse_fallback(data: &[u8]) -> Result<ir::Items, traits::Error> {
    parse_wasm(data)
}