extern crate proc_macro;
mod buffer;
mod bytecode;
use crate::buffer::{InputBuffer, OutputBuffer};
use crate::bytecode::Bytecode;
use proc_macro::{Delimiter, Group, Ident, Literal, Punct, Spacing, Span, TokenStream, TokenTree};
use std::io::{ErrorKind, Read, Write};
use std::iter::FromIterator;
use std::path::Path;
use std::process::{Command, ExitStatus, Stdio};
use std::str::FromStr;
#[proc_macro_derive(Serialize, attributes(serde))]
pub fn derive_serialize(input: TokenStream) -> TokenStream {
derive(0, input)
}
#[proc_macro_derive(Deserialize, attributes(serde))]
pub fn derive_deserialize(input: TokenStream) -> TokenStream {
derive(1 + cfg!(feature = "deserialize_in_place") as u8, input)
}
fn derive(select: u8, input: TokenStream) -> TokenStream {
let mut memory = TokenMemory::default();
let mut buf = OutputBuffer::new();
buf.write_u8(select);
memory.spans.push(Span::call_site());
for token in input {
memory.linearize_token(token, &mut buf);
}
let exe_path = Path::new(concat!(
env!("CARGO_MANIFEST_DIR"),
"/serde_derive-x86_64-unknown-linux-gnu",
));
let mut child = match Command::new(exe_path)
.stdin(Stdio::piped())
.stdout(Stdio::piped())
.spawn()
{
Ok(child) => child,
Err(io_error) => {
if io_error.kind() == ErrorKind::NotFound {
panic!(
"file missing from serde_derive manifest directory during macro expansion: {}",
exe_path.display(),
);
} else {
panic!("failed to spawn process: {}", io_error);
}
}
};
let mut stdin = child.stdin.take().unwrap();
let mut buf = buf.into_bytes();
stdin.write_all(&buf).unwrap();
drop(stdin);
let mut stdout = child.stdout.take().unwrap();
buf.clear();
stdout.read_to_end(&mut buf).unwrap();
let success = child.wait().as_ref().map_or(true, ExitStatus::success);
if !success || buf.is_empty() {
panic!();
}
let mut buf = InputBuffer::new(&buf);
memory.receive(&mut buf)
}
#[derive(Default)]
struct TokenMemory {
spans: Vec<Span>,
groups: Vec<Group>,
idents: Vec<Ident>,
puncts: Vec<Punct>,
literals: Vec<Literal>,
}
enum Kind {
Group(Delimiter),
Ident,
Punct(Spacing),
Literal,
}
impl TokenMemory {
fn linearize_token(&mut self, token: TokenTree, buf: &mut OutputBuffer) {
match token {
TokenTree::Group(group) => {
let mut len = 0usize;
for token in group.stream() {
self.linearize_token(token, buf);
len += 1;
}
assert!(len <= u32::MAX as usize);
buf.write_u8(match group.delimiter() {
Delimiter::Parenthesis => Bytecode::GROUP_PARENTHESIS,
Delimiter::Brace => Bytecode::GROUP_BRACE,
Delimiter::Bracket => Bytecode::GROUP_BRACKET,
Delimiter::None => Bytecode::GROUP_NONE,
});
buf.write_u32(len as u32);
self.spans
.extend([group.span(), group.span_open(), group.span_close()]);
self.groups.push(group);
}
TokenTree::Ident(ident) => {
buf.write_u8(Bytecode::IDENT);
let repr = ident.to_string();
assert!(repr.len() <= u16::MAX as usize);
buf.write_u16(repr.len() as u16);
buf.write_str(&repr);
self.spans.push(ident.span());
self.idents.push(ident);
}
TokenTree::Punct(punct) => {
buf.write_u8(match punct.spacing() {
Spacing::Alone => Bytecode::PUNCT_ALONE,
Spacing::Joint => Bytecode::PUNCT_JOINT,
});
let ch = punct.as_char();
assert!(ch.is_ascii());
buf.write_u8(ch as u8);
self.spans.push(punct.span());
self.puncts.push(punct);
}
TokenTree::Literal(literal) => {
buf.write_u8(Bytecode::LITERAL);
let repr = literal.to_string();
assert!(repr.len() <= u16::MAX as usize);
buf.write_u16(repr.len() as u16);
buf.write_str(&repr);
self.spans.push(literal.span());
self.literals.push(literal);
}
}
}
fn receive(&self, buf: &mut InputBuffer) -> TokenStream {
let mut trees = Vec::new();
while !buf.is_empty() {
match match buf.read_u8() {
Bytecode::GROUP_PARENTHESIS => Kind::Group(Delimiter::Parenthesis),
Bytecode::GROUP_BRACE => Kind::Group(Delimiter::Brace),
Bytecode::GROUP_BRACKET => Kind::Group(Delimiter::Bracket),
Bytecode::GROUP_NONE => Kind::Group(Delimiter::None),
Bytecode::IDENT => Kind::Ident,
Bytecode::PUNCT_ALONE => Kind::Punct(Spacing::Alone),
Bytecode::PUNCT_JOINT => Kind::Punct(Spacing::Joint),
Bytecode::LITERAL => Kind::Literal,
Bytecode::LOAD_GROUP => {
let identity = buf.read_u32();
let group = self.groups[identity as usize].clone();
trees.push(TokenTree::Group(group));
continue;
}
Bytecode::LOAD_IDENT => {
let identity = buf.read_u32();
let ident = self.idents[identity as usize].clone();
trees.push(TokenTree::Ident(ident));
continue;
}
Bytecode::LOAD_PUNCT => {
let identity = buf.read_u32();
let punct = self.puncts[identity as usize].clone();
trees.push(TokenTree::Punct(punct));
continue;
}
Bytecode::LOAD_LITERAL => {
let identity = buf.read_u32();
let literal = self.literals[identity as usize].clone();
trees.push(TokenTree::Literal(literal));
continue;
}
Bytecode::SET_SPAN => {
trees.last_mut().unwrap().set_span(self.read_span(buf));
continue;
}
_ => unreachable!(),
} {
Kind::Group(delimiter) => {
let len = buf.read_u32();
let stream = trees.drain(trees.len() - len as usize..).collect();
let group = Group::new(delimiter, stream);
trees.push(TokenTree::Group(group));
}
Kind::Ident => {
let len = buf.read_u16();
let repr = buf.read_str(len as usize);
let span = self.read_span(buf);
let ident = if let Some(repr) = repr.strip_prefix("r#") {
Ident::new_raw(repr, span)
} else {
Ident::new(repr, span)
};
trees.push(TokenTree::Ident(ident));
}
Kind::Punct(spacing) => {
let ch = buf.read_u8();
assert!(ch.is_ascii());
let punct = Punct::new(ch as char, spacing);
trees.push(TokenTree::Punct(punct));
}
Kind::Literal => {
let len = buf.read_u16();
let repr = buf.read_str(len as usize);
let literal = Literal::from_str(repr).unwrap();
trees.push(TokenTree::Literal(literal));
}
}
}
TokenStream::from_iter(trees)
}
fn read_span(&self, buf: &mut InputBuffer) -> Span {
let lo = buf.read_u32();
let hi = buf.read_u32();
let span = self.spans[lo as usize];
if lo == hi {
span
} else {
#[cfg(any())] return span.join(self.spans[hi as usize]).unwrap_or(span);
span
}
}
}