Use a u64 for the rmeta root position

This commit is contained in:
Ben Kimock 2023-11-26 20:45:56 -05:00
parent 59f5d51852
commit 5ef5e55749

View File

@ -120,13 +120,18 @@ pub fn read_version(dylib_path: &AbsPath) -> io::Result<String> {
let version = u32::from_be_bytes([dot_rustc[4], dot_rustc[5], dot_rustc[6], dot_rustc[7]]);
// Last supported version is:
// https://github.com/rust-lang/rust/commit/0696e79f2740ad89309269b460579e548a5cd632
let snappy_portion = match version {
5 | 6 => &dot_rustc[8..],
let (snappy_portion, bytes_before_version) = match version {
5 | 6 => (&dot_rustc[8..], 13),
7 | 8 => {
let len_bytes = &dot_rustc[8..12];
let data_len = u32::from_be_bytes(len_bytes.try_into().unwrap()) as usize;
&dot_rustc[12..data_len + 12]
(&dot_rustc[12..data_len + 12], 13)
}
9 => {
let len_bytes = &dot_rustc[8..16];
let data_len = u64::from_le_bytes(len_bytes.try_into().unwrap()) as usize;
(&dot_rustc[16..data_len + 12], 17)
}
_ => {
return Err(io::Error::new(
io::ErrorKind::InvalidData,
@ -142,15 +147,15 @@ pub fn read_version(dylib_path: &AbsPath) -> io::Result<String> {
Box::new(SnapDecoder::new(snappy_portion))
};
// the bytes before version string bytes, so this basically is:
// We're going to skip over the bytes before the version string, so basically:
// 8 bytes for [b'r',b'u',b's',b't',0,0,0,5]
// 4 bytes for [crate root bytes]
// 4 or 8 bytes for [crate root bytes]
// 1 byte for length of version string
// so 13 bytes in total, and we should check the 13th byte
// so 13 or 17 bytes in total, and we should check the last of those bytes
// to know the length
let mut bytes_before_version = [0u8; 13];
let mut bytes_before_version = vec![0u8; bytes_before_version];
uncompressed.read_exact(&mut bytes_before_version)?;
let length = bytes_before_version[12];
let length = *bytes_before_version.last().unwrap();
let mut version_string_utf8 = vec![0u8; length as usize];
uncompressed.read_exact(&mut version_string_utf8)?;