Witch of Git - jade-rose/blob - toolchain/src/lib.rs

   1 pub mod inst;
   2 #[cfg(target_arch = "wasm32")]
   3 pub mod js;
   4
   5 use inst::Decode;
   6 pub use inst::Inst;
   7 use std::io::{self, Read};
   8
   9 pub enum Error {
  10     Io { position: usize, error: io::Error },
  11 }
  12
  13 pub fn disassemble(reader: &mut impl io::Read) -> Result<Vec<Inst>, Error> {
  14     let mut results = Vec::new();
  15     let mut reader = PositionedRead::new(reader);
  16     loop {
  17         let position = reader.position;
  18         match Inst::decode(&mut reader) {
  19             Ok(inst) => results.push(inst),
  20             Err(err) if err.kind() == io::ErrorKind::UnexpectedEof => break,
  21             Err(err) => {
  22                 return Err(Error::Io {
  23                     position,
  24                     error: err,
  25                 })
  26             }
  27         }
  28     }
  29     Ok(results)
  30 }
  31
  32 struct PositionedRead<'a, R> {
  33     inner: &'a mut R,
  34     position: usize,
  35 }
  36
  37 impl<'a, R> PositionedRead<'a, R> {
  38     pub fn new(inner: &'a mut R) -> Self {
  39         PositionedRead { inner, position: 0 }
  40     }
  41 }
  42
  43 impl<'a, R: Read> Read for PositionedRead<'a, R> {
  44     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
  45         let read = self.inner.read(buf)?;
  46         self.position += read;
  47         Ok(read)
  48     }
  49 }
  50
  51 #[cfg(test)]
  52 mod test {
  53     use super::*;
  54     use io::{self, Cursor};
  55     #[test]
  56     fn test_disassemble_errors_at_end() {
  57         let mut cursor = Cursor::new(&[0xff]);
  58         let err = Inst::decode(&mut cursor).unwrap_err();
  59         assert_eq!(err.kind(), io::ErrorKind::InvalidInput);
  60         assert_eq!(
  61             err.get_ref().map(|x| x.to_string()),
  62             Some("Extended instruction missing operand".into())
  63         );
  64     }
  65 }