Merge pull request #2514 from dtolnay/precompiled

Add experiment to produce precompiled builds of serde_derive

precompiled/.gitignore

@@ -0,0 +1 @@
+/x86_64-unknown-linux-gnu/serde_derive

precompiled/Cargo.toml

@@ -0,0 +1,14 @@
+[workspace]
+members = ["proc-macro2", "serde_derive"]
+resolver = "2"
+
+[patch.crates-io]
+proc-macro2 = { path = "proc-macro2" }
+
+[profile.precompiled]
+inherits = "release"
+codegen-units = 1
+lto = true
+opt-level = "z"
+panic = "abort"
+strip = true

precompiled/build.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &>/dev/null
+
+cargo +nightly build \
+    --manifest-path serde_derive/Cargo.toml \
+    --bin serde_derive \
+    --profile precompiled \
+    -Z unstable-options \
+    -Z build-std=std,panic_abort \
+    -Z build-std-features=panic_immediate_abort \
+    --target x86_64-unknown-linux-musl \
+    --out-dir x86_64-unknown-linux-gnu
+
+#upx --best --lzma x86_64-unknown-linux-gnu/serde_derive

precompiled/proc-macro2/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "proc-macro2"
+version = "1.0.66"
+edition = "2021"
+publish = false
+
+[dependencies]
+proc-macro2 = { package = "proc-macro2-fallback", version = "1" }

precompiled/proc-macro2/src/lib.rs

@@ -0,0 +1,816 @@
+#[doc(hidden)]
+pub mod watt;
+
+use crate::extra::DelimSpan;
+use crate::watt::Identity;
+use std::cmp::Ordering;
+use std::fmt::{self, Debug, Display};
+use std::hash::{Hash, Hasher};
+use std::ops::RangeBounds;
+use std::str::FromStr;
+
+pub use proc_macro2::{Delimiter, Spacing};
+
+#[derive(Copy, Clone)]
+pub struct Span {
+    lo: u32,
+    hi: u32,
+}
+
+impl Span {
+    pub fn call_site() -> Self {
+        Span { lo: 0, hi: 0 }
+    }
+
+    pub fn join(&self, other: Self) -> Option<Self> {
+        Some(Span {
+            lo: self.lo,
+            hi: other.hi,
+        })
+    }
+}
+
+#[derive(Clone)]
+pub enum TokenTree {
+    Group(Group),
+    Ident(Ident),
+    Punct(Punct),
+    Literal(Literal),
+}
+
+impl TokenTree {
+    pub fn span(&self) -> Span {
+        match self {
+            TokenTree::Group(group) => group.span(),
+            TokenTree::Ident(ident) => ident.span(),
+            TokenTree::Punct(punct) => punct.span(),
+            TokenTree::Literal(literal) => literal.span(),
+        }
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        match self {
+            TokenTree::Group(group) => group.set_span(span),
+            TokenTree::Ident(ident) => ident.set_span(span),
+            TokenTree::Punct(punct) => punct.set_span(span),
+            TokenTree::Literal(literal) => literal.set_span(span),
+        }
+    }
+}
+
+impl From<Group> for TokenTree {
+    fn from(group: Group) -> Self {
+        TokenTree::Group(group)
+    }
+}
+
+impl From<Ident> for TokenTree {
+    fn from(ident: Ident) -> Self {
+        TokenTree::Ident(ident)
+    }
+}
+
+impl From<Punct> for TokenTree {
+    fn from(punct: Punct) -> Self {
+        TokenTree::Punct(punct)
+    }
+}
+
+impl From<Literal> for TokenTree {
+    fn from(literal: Literal) -> Self {
+        TokenTree::Literal(literal)
+    }
+}
+
+impl Debug for TokenTree {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            TokenTree::Group(group) => Debug::fmt(group, formatter),
+            TokenTree::Ident(ident) => {
+                let mut debug = formatter.debug_struct("Ident");
+                debug.field("sym", &format_args!("{}", ident));
+                debug.finish()
+            }
+            TokenTree::Punct(punct) => Debug::fmt(punct, formatter),
+            TokenTree::Literal(literal) => Debug::fmt(literal, formatter),
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct Group {
+    delimiter: Delimiter,
+    stream: Vec<TokenTree>,
+    span: Span,
+    span_open: Span,
+    span_close: Span,
+    identity: u32,
+}
+
+impl Group {
+    pub fn new(delimiter: Delimiter, stream: TokenStream) -> Self {
+        Group {
+            delimiter,
+            stream: stream.content,
+            span: Span::call_site(),
+            span_open: Span::call_site(),
+            span_close: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn stream(&self) -> TokenStream {
+        TokenStream {
+            content: self.stream.clone(),
+        }
+    }
+
+    pub fn delimiter(&self) -> Delimiter {
+        self.delimiter
+    }
+
+    pub fn span(&self) -> Span {
+        self.span
+    }
+
+    pub fn span_open(&self) -> Span {
+        self.span_open
+    }
+
+    pub fn span_close(&self) -> Span {
+        self.span_close
+    }
+
+    pub fn delim_span(&self) -> DelimSpan {
+        DelimSpan {
+            open: self.span_open(),
+            close: self.span_close(),
+        }
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.span = span;
+        self.identity |= Identity::RESPANNED;
+    }
+}
+
+impl Display for Group {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let (open, close) = match self.delimiter {
+            Delimiter::Parenthesis => ("(", ")"),
+            Delimiter::Brace => ("{ ", "}"),
+            Delimiter::Bracket => ("[", "]"),
+            Delimiter::None => ("", ""),
+        };
+
+        formatter.write_str(open)?;
+        display_tokens(&self.stream, formatter)?;
+        if self.delimiter == Delimiter::Brace && !self.stream.is_empty() {
+            formatter.write_str(" ")?;
+        }
+        formatter.write_str(close)?;
+
+        Ok(())
+    }
+}
+
+impl Debug for Group {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        let mut debug = formatter.debug_struct("Group");
+        debug.field("delimiter", &self.delimiter);
+        debug.field("stream", &self.stream);
+        debug.finish()
+    }
+}
+
+#[derive(Clone)]
+pub struct Ident {
+    fallback: proc_macro2::Ident,
+    span: Span,
+    identity: u32,
+}
+
+impl Ident {
+    pub fn new(string: &str, span: Span) -> Self {
+        Ident {
+            fallback: proc_macro2::Ident::new(string, proc_macro2::Span::call_site()),
+            span,
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn new_raw(string: &str, span: Span) -> Self {
+        Ident {
+            fallback: proc_macro2::Ident::new_raw(string, proc_macro2::Span::call_site()),
+            span,
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn span(&self) -> Span {
+        self.span
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.span = span;
+        self.identity |= Identity::RESPANNED;
+    }
+}
+
+impl Display for Ident {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.fallback, formatter)
+    }
+}
+
+impl Debug for Ident {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Debug::fmt(&self.fallback, formatter)
+    }
+}
+
+impl Eq for Ident {}
+
+impl PartialEq for Ident {
+    fn eq(&self, other: &Self) -> bool {
+        PartialEq::eq(&self.fallback, &other.fallback)
+    }
+}
+
+impl<T> PartialEq<T> for Ident
+where
+    T: ?Sized + AsRef<str>,
+{
+    fn eq(&self, other: &T) -> bool {
+        PartialEq::eq(&self.fallback, other)
+    }
+}
+
+impl Ord for Ident {
+    fn cmp(&self, other: &Self) -> Ordering {
+        Ord::cmp(&self.fallback, &other.fallback)
+    }
+}
+
+impl PartialOrd for Ident {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        PartialOrd::partial_cmp(&self.fallback, &other.fallback)
+    }
+}
+
+impl Hash for Ident {
+    fn hash<H: Hasher>(&self, hasher: &mut H) {
+        Hash::hash(&self.fallback, hasher);
+    }
+}
+
+#[derive(Clone)]
+pub struct Punct {
+    fallback: proc_macro2::Punct,
+    span: Span,
+    identity: u32,
+}
+
+impl Punct {
+    pub fn new(ch: char, spacing: Spacing) -> Self {
+        Punct {
+            fallback: proc_macro2::Punct::new(ch, spacing),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn as_char(&self) -> char {
+        self.fallback.as_char()
+    }
+
+    pub fn spacing(&self) -> Spacing {
+        self.fallback.spacing()
+    }
+
+    pub fn span(&self) -> Span {
+        self.span
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.span = span;
+        self.identity |= Identity::RESPANNED;
+    }
+}
+
+impl Display for Punct {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.fallback, formatter)
+    }
+}
+
+impl Debug for Punct {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Debug::fmt(&self.fallback, formatter)
+    }
+}
+
+#[derive(Clone)]
+pub struct Literal {
+    fallback: proc_macro2::Literal,
+    span: Span,
+    identity: u32,
+}
+
+impl Literal {
+    pub fn u8_suffixed(n: u8) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::u8_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn u16_suffixed(n: u16) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::u16_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn u32_suffixed(n: u32) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::u32_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn u64_suffixed(n: u64) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::u64_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn u128_suffixed(n: u128) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::u128_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn usize_suffixed(n: usize) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::usize_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn i8_suffixed(n: i8) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::i8_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn i16_suffixed(n: i16) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::i16_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn i32_suffixed(n: i32) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::i32_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn i64_suffixed(n: i64) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::i64_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn i128_suffixed(n: i128) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::i128_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn isize_suffixed(n: isize) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::isize_suffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn u8_unsuffixed(n: u8) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::u8_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn u16_unsuffixed(n: u16) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::u16_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn u32_unsuffixed(n: u32) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::u32_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn u64_unsuffixed(n: u64) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::u64_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn u128_unsuffixed(n: u128) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::u128_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn usize_unsuffixed(n: usize) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::usize_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn i8_unsuffixed(n: i8) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::i8_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn i16_unsuffixed(n: i16) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::i16_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn i32_unsuffixed(n: i32) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::i32_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn i64_unsuffixed(n: i64) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::i64_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn i128_unsuffixed(n: i128) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::i128_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn isize_unsuffixed(n: isize) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::isize_unsuffixed(n),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn f64_unsuffixed(f: f64) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::f64_unsuffixed(f),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn f64_suffixed(f: f64) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::f64_suffixed(f),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn f32_unsuffixed(f: f32) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::f32_unsuffixed(f),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn f32_suffixed(f: f32) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::f32_suffixed(f),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn string(string: &str) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::string(string),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn character(ch: char) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::character(ch),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn byte_string(s: &[u8]) -> Self {
+        Literal {
+            fallback: proc_macro2::Literal::byte_string(s),
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        }
+    }
+
+    pub fn span(&self) -> Span {
+        self.span
+    }
+
+    pub fn set_span(&mut self, span: Span) {
+        self.span = span;
+        self.identity |= Identity::RESPANNED;
+    }
+
+    pub fn subspan<R: RangeBounds<usize>>(&self, range: R) -> Option<Span> {
+        let _ = range;
+        None
+    }
+}
+
+impl FromStr for Literal {
+    type Err = LexError;
+
+    fn from_str(repr: &str) -> Result<Self, Self::Err> {
+        let fallback = match proc_macro2::Literal::from_str(repr) {
+            Ok(literal) => literal,
+            Err(error) => {
+                return Err(LexError {
+                    fallback: error,
+                    span: Span::call_site(),
+                });
+            }
+        };
+        Ok(Literal {
+            fallback,
+            span: Span::call_site(),
+            identity: Identity::NOVEL,
+        })
+    }
+}
+
+impl Display for Literal {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Display::fmt(&self.fallback, formatter)
+    }
+}
+
+impl Debug for Literal {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Debug::fmt(&self.fallback, formatter)
+    }
+}
+
+#[derive(Clone)]
+pub struct TokenStream {
+    content: Vec<TokenTree>,
+}
+
+impl TokenStream {
+    pub fn new() -> Self {
+        TokenStream {
+            content: Vec::new(),
+        }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.content.is_empty()
+    }
+}
+
+impl IntoIterator for TokenStream {
+    type Item = TokenTree;
+    type IntoIter = token_stream::IntoIter;
+
+    fn into_iter(self) -> Self::IntoIter {
+        token_stream::IntoIter {
+            iter: self.content.into_iter(),
+        }
+    }
+}
+
+impl Extend<TokenStream> for TokenStream {
+    fn extend<I: IntoIterator<Item = TokenStream>>(&mut self, streams: I) {
+        self.content.extend(streams.into_iter().flatten());
+    }
+}
+
+impl Extend<TokenTree> for TokenStream {
+    fn extend<I: IntoIterator<Item = TokenTree>>(&mut self, streams: I) {
+        self.content.extend(streams);
+    }
+}
+
+impl FromIterator<TokenStream> for TokenStream {
+    fn from_iter<I: IntoIterator<Item = TokenStream>>(streams: I) -> Self {
+        let content = streams.into_iter().flatten().collect();
+        TokenStream { content }
+    }
+}
+
+impl FromIterator<TokenTree> for TokenStream {
+    fn from_iter<I: IntoIterator<Item = TokenTree>>(streams: I) -> Self {
+        let content = streams.into_iter().collect();
+        TokenStream { content }
+    }
+}
+
+impl FromStr for TokenStream {
+    type Err = LexError;
+
+    fn from_str(string: &str) -> Result<Self, Self::Err> {
+        let fallback = match proc_macro2::TokenStream::from_str(string) {
+            Ok(token_stream) => token_stream,
+            Err(error) => {
+                return Err(LexError {
+                    fallback: error,
+                    span: Span::call_site(),
+                });
+            }
+        };
+
+        fn convert_token_stream(stream: proc_macro2::TokenStream) -> TokenStream {
+            TokenStream {
+                content: stream.into_iter().map(convert_token_tree).collect(),
+            }
+        }
+
+        fn convert_token_tree(token: proc_macro2::TokenTree) -> TokenTree {
+            match token {
+                proc_macro2::TokenTree::Group(group) => TokenTree::Group(Group::new(
+                    group.delimiter(),
+                    convert_token_stream(group.stream()),
+                )),
+                proc_macro2::TokenTree::Ident(ident) => TokenTree::Ident(Ident {
+                    fallback: ident,
+                    span: Span::call_site(),
+                    identity: Identity::NOVEL,
+                }),
+                proc_macro2::TokenTree::Punct(punct) => TokenTree::Punct(Punct {
+                    fallback: punct,
+                    span: Span::call_site(),
+                    identity: Identity::NOVEL,
+                }),
+                proc_macro2::TokenTree::Literal(literal) => TokenTree::Literal(Literal {
+                    fallback: literal,
+                    span: Span::call_site(),
+                    identity: Identity::NOVEL,
+                }),
+            }
+        }
+
+        Ok(convert_token_stream(fallback))
+    }
+}
+
+fn display_tokens(tokens: &[TokenTree], formatter: &mut fmt::Formatter) -> fmt::Result {
+    let mut joint = false;
+    for (i, token) in tokens.iter().enumerate() {
+        if i != 0 && !joint {
+            write!(formatter, " ")?;
+        }
+        joint = false;
+        match token {
+            TokenTree::Group(group) => Display::fmt(group, formatter),
+            TokenTree::Ident(ident) => Display::fmt(ident, formatter),
+            TokenTree::Punct(punct) => {
+                joint = punct.spacing() == Spacing::Joint;
+                Display::fmt(punct, formatter)
+            }
+            TokenTree::Literal(literal) => Display::fmt(literal, formatter),
+        }?;
+    }
+
+    Ok(())
+}
+
+impl Display for TokenStream {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        display_tokens(&self.content, formatter)
+    }
+}
+
+impl Debug for TokenStream {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("TokenStream ")?;
+        formatter.debug_list().entries(&self.content).finish()
+    }
+}
+
+pub struct LexError {
+    fallback: proc_macro2::LexError,
+    span: Span,
+}
+
+impl LexError {
+    pub fn span(&self) -> Span {
+        self.span
+    }
+}
+
+impl Debug for LexError {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        Debug::fmt(&self.fallback, formatter)
+    }
+}
+
+pub mod token_stream {
+    use super::*;
+
+    #[derive(Clone)]
+    pub struct IntoIter {
+        pub(crate) iter: <Vec<TokenTree> as IntoIterator>::IntoIter,
+    }
+
+    impl Iterator for IntoIter {
+        type Item = TokenTree;
+
+        fn next(&mut self) -> Option<Self::Item> {
+            self.iter.next()
+        }
+
+        fn size_hint(&self) -> (usize, Option<usize>) {
+            self.iter.size_hint()
+        }
+    }
+}
+
+pub mod extra {
+    use crate::Span;
+
+    #[derive(Copy, Clone)]
+    pub struct DelimSpan {
+        pub(crate) open: Span,
+        pub(crate) close: Span,
+    }
+
+    impl DelimSpan {
+        pub fn join(&self) -> Span {
+            Span {
+                lo: self.open.lo,
+                hi: self.close.hi,
+            }
+        }
+
+        pub fn open(&self) -> Span {
+            self.open
+        }
+
+        pub fn close(&self) -> Span {
+            self.close
+        }
+    }
+}

precompiled/proc-macro2/src/watt/buffer.rs

@@ -0,0 +1,69 @@
+use std::str;
+
+pub struct OutputBuffer {
+    bytes: Vec<u8>,
+}
+
+impl OutputBuffer {
+    pub fn new() -> Self {
+        OutputBuffer { bytes: Vec::new() }
+    }
+
+    pub fn write_u8(&mut self, value: u8) {
+        self.bytes.push(value);
+    }
+
+    pub fn write_u16(&mut self, value: u16) {
+        self.bytes.extend_from_slice(&value.to_le_bytes());
+    }
+
+    pub fn write_u32(&mut self, value: u32) {
+        self.bytes.extend_from_slice(&value.to_le_bytes());
+    }
+
+    pub fn write_str(&mut self, value: &str) {
+        self.bytes.extend_from_slice(value.as_bytes());
+    }
+
+    pub fn into_bytes(self) -> Vec<u8> {
+        self.bytes
+    }
+}
+
+pub struct InputBuffer<'a> {
+    bytes: &'a [u8],
+}
+
+impl<'a> InputBuffer<'a> {
+    pub fn new(bytes: &'a [u8]) -> Self {
+        InputBuffer { bytes }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.bytes.is_empty()
+    }
+
+    pub fn read_u8(&mut self) -> u8 {
+        let (first, rest) = self.bytes.split_first().unwrap();
+        self.bytes = rest;
+        *first
+    }
+
+    pub fn read_u16(&mut self) -> u16 {
+        let (value, rest) = self.bytes.split_at(2);
+        self.bytes = rest;
+        u16::from_le_bytes([value[0], value[1]])
+    }
+
+    pub fn read_u32(&mut self) -> u32 {
+        let (value, rest) = self.bytes.split_at(4);
+        self.bytes = rest;
+        u32::from_le_bytes([value[0], value[1], value[2], value[3]])
+    }
+
+    pub fn read_str(&mut self, len: usize) -> &'a str {
+        let (string, rest) = self.bytes.split_at(len);
+        self.bytes = rest;
+        str::from_utf8(string).unwrap()
+    }
+}

precompiled/proc-macro2/src/watt/bytecode.rs

@@ -0,0 +1,17 @@
+pub enum Bytecode {}
+
+impl Bytecode {
+    pub const GROUP_PARENTHESIS: u8 = 0;
+    pub const GROUP_BRACE: u8 = 1;
+    pub const GROUP_BRACKET: u8 = 2;
+    pub const GROUP_NONE: u8 = 3;
+    pub const IDENT: u8 = 4;
+    pub const PUNCT_ALONE: u8 = 5;
+    pub const PUNCT_JOINT: u8 = 6;
+    pub const LITERAL: u8 = 7;
+    pub const LOAD_GROUP: u8 = 8;
+    pub const LOAD_IDENT: u8 = 9;
+    pub const LOAD_PUNCT: u8 = 10;
+    pub const LOAD_LITERAL: u8 = 11;
+    pub const SET_SPAN: u8 = 12;
+}

precompiled/proc-macro2/src/watt/mod.rs

@@ -0,0 +1,196 @@
+pub mod buffer;
+pub mod bytecode;
+
+use crate::watt::buffer::{InputBuffer, OutputBuffer};
+use crate::watt::bytecode::Bytecode;
+use crate::{Delimiter, Group, Ident, Literal, Punct, Spacing, Span, TokenStream, TokenTree};
+use std::str::FromStr;
+
+pub enum Kind {
+    Group(Delimiter),
+    Ident,
+    Punct(Spacing),
+    Literal,
+}
+
+pub enum Identity {}
+
+impl Identity {
+    pub const RESPANNED: u32 = 1 << 31;
+    pub const NOVEL: u32 = u32::MAX;
+}
+
+impl Span {
+    fn is_call_site(&self) -> bool {
+        self.lo == 0 && self.hi == 0
+    }
+}
+
+fn post_increment(counter: &mut u32) -> impl FnMut() -> u32 + '_ {
+    || {
+        let value = *counter;
+        *counter += 1;
+        value
+    }
+}
+
+pub fn load(buf: &mut InputBuffer) -> TokenStream {
+    let mut span_counter = 0;
+    let mut next_span = post_increment(&mut span_counter);
+    let mut next_span = || {
+        let next = next_span();
+        Span { lo: next, hi: next }
+    };
+
+    let [mut group_counter, mut ident_counter, mut punct_counter, mut literal_counter] = [0; 4];
+    let mut next_group = post_increment(&mut group_counter);
+    let mut next_ident = post_increment(&mut ident_counter);
+    let mut next_punct = post_increment(&mut punct_counter);
+    let mut next_literal = post_increment(&mut literal_counter);
+
+    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,
+            _ => unreachable!(),
+        } {
+            Kind::Group(delimiter) => {
+                let len = buf.read_u32();
+                let stream = trees.drain(trees.len() - len as usize..).collect();
+                trees.push(TokenTree::Group(Group {
+                    delimiter,
+                    stream,
+                    span: next_span(),
+                    span_open: next_span(),
+                    span_close: next_span(),
+                    identity: next_group(),
+                }));
+            }
+            Kind::Ident => {
+                let len = buf.read_u16();
+                let repr = buf.read_str(len as usize);
+                trees.push(TokenTree::Ident(Ident {
+                    fallback: proc_macro2::Ident::new(repr, proc_macro2::Span::call_site()),
+                    span: next_span(),
+                    identity: next_ident(),
+                }));
+            }
+            Kind::Punct(spacing) => {
+                let ch = buf.read_u8();
+                assert!(ch.is_ascii());
+                trees.push(TokenTree::Punct(Punct {
+                    fallback: proc_macro2::Punct::new(ch as char, spacing),
+                    span: next_span(),
+                    identity: next_punct(),
+                }));
+            }
+            Kind::Literal => {
+                let len = buf.read_u16();
+                let repr = buf.read_str(len as usize);
+                trees.push(TokenTree::Literal(Literal {
+                    fallback: proc_macro2::Literal::from_str(repr).unwrap(),
+                    span: next_span(),
+                    identity: next_literal(),
+                }));
+            }
+        }
+    }
+
+    TokenStream { content: trees }
+}
+
+pub fn linearize(tokens: TokenStream) -> Vec<u8> {
+    let mut buf = OutputBuffer::new();
+    for token in &tokens.content {
+        linearize_token(token, &mut buf);
+    }
+    buf.into_bytes()
+}
+
+fn linearize_token(token: &TokenTree, buf: &mut OutputBuffer) {
+    let needs_span;
+    match token {
+        TokenTree::Group(group) => {
+            if group.identity < Identity::NOVEL {
+                buf.write_u8(Bytecode::LOAD_GROUP);
+                buf.write_u32(group.identity & !Identity::RESPANNED);
+                needs_span = group.identity >= Identity::RESPANNED;
+            } else {
+                let len = group.stream.len();
+                assert!(len <= u32::MAX as usize);
+                for token in &group.stream {
+                    linearize_token(token, buf);
+                }
+                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);
+                needs_span = !group.span.is_call_site();
+            }
+        }
+        TokenTree::Ident(ident) => {
+            if ident.identity < Identity::NOVEL {
+                buf.write_u8(Bytecode::LOAD_IDENT);
+                buf.write_u32(ident.identity & !Identity::RESPANNED);
+                needs_span = ident.identity >= Identity::RESPANNED;
+            } else {
+                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);
+                linearize_span(ident.span, buf);
+                needs_span = false;
+            }
+        }
+        TokenTree::Punct(punct) => {
+            if punct.identity < Identity::NOVEL {
+                buf.write_u8(Bytecode::LOAD_PUNCT);
+                buf.write_u32(punct.identity & !Identity::RESPANNED);
+                needs_span = punct.identity >= Identity::RESPANNED;
+            } else {
+                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);
+                needs_span = !punct.span.is_call_site();
+            }
+        }
+        TokenTree::Literal(literal) => {
+            if literal.identity < Identity::NOVEL {
+                buf.write_u8(Bytecode::LOAD_LITERAL);
+                buf.write_u32(literal.identity & !Identity::RESPANNED);
+                needs_span = literal.identity >= Identity::RESPANNED;
+            } else {
+                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);
+                needs_span = !literal.span.is_call_site();
+            }
+        }
+    }
+    if needs_span {
+        buf.write_u8(Bytecode::SET_SPAN);
+        linearize_span(token.span(), buf);
+    }
+}
+
+fn linearize_span(span: Span, buf: &mut OutputBuffer) {
+    buf.write_u32(span.lo);
+    buf.write_u32(span.hi);
+}

precompiled/serde_derive/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "serde_derive"
+version = "1.0.171"
+authors = ["David Tolnay <dtolnay@gmail.com>"]
+publish = false
+
+[lib]
+doctest = false
+
+[[bin]]
+name = "serde_derive"
+path = "main.rs"
+
+[dependencies]
+proc-macro2 = "1"
+quote = { version = "1", default-features = false }
+syn = { version = "2.0.25", default-features = false, features = ["clone-impls", "derive", "parsing", "printing"] }

precompiled/serde_derive/build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("cargo:rustc-cfg=precompiled");
+}

precompiled/serde_derive/main.rs

@@ -0,0 +1,22 @@
+extern crate proc_macro2;
+
+use proc_macro2::watt;
+use proc_macro2::watt::buffer::InputBuffer;
+use std::io::{self, Read, Write};
+
+fn main() {
+    let mut buf = Vec::new();
+    io::stdin().read_to_end(&mut buf).unwrap();
+
+    let mut buf = InputBuffer::new(&buf);
+    let derive = match buf.read_u8() {
+        0 => serde_derive::derive_serialize,
+        1 => serde_derive::derive_deserialize,
+        _ => unreachable!(),
+    };
+
+    let input = watt::load(&mut buf);
+    let output = derive(input);
+    let bytes = watt::linearize(output);
+    io::stdout().write_all(&bytes).unwrap();
+}

precompiled/serde_derive/src

@@ -0,0 +1 @@
+../../serde_derive/src

precompiled/x86_64-unknown-linux-gnu/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "serde_derive-x86_64-unknown-linux-gnu"
+version = "1.0.171-alpha.0"
+authors = ["David Tolnay <dtolnay@gmail.com>"]
+categories = ["no-std", "no-std::no-alloc"]
+description = "Precompiled implementation of #[derive(Serialize, Deserialize)]"
+documentation = "https://serde.rs/derive.html"
+edition = "2015"
+homepage = "https://serde.rs"
+include = ["serde_derive", "src"]
+keywords = ["serde", "serialization", "no_std", "derive"]
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/serde-rs/serde"
+
+[lib]
+name = "serde_derive"
+proc-macro = true
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[workspace]

precompiled/x86_64-unknown-linux-gnu/README.md

@@ -0,0 +1,16 @@
+```toml
+# Cargo.toml
+
+[dependencies]
+serde = "1"  # no features=["derive"]
+serde_derive-x86_64-unknown-linux-gnu = "1.0.171-alpha.0"
+```
+
+```rust
+use serde_derive::{Deserialize, Serialize};
+
+#[derive(Deserialize, Serialize)]
+pub struct MyStruct {
+    /* ... */
+}
+```

precompiled/x86_64-unknown-linux-gnu/src/buffer.rs

@@ -0,0 +1 @@
+../../proc-macro2/src/watt/buffer.rs

precompiled/x86_64-unknown-linux-gnu/src/bytecode.rs

@@ -0,0 +1 @@
+../../proc-macro2/src/watt/bytecode.rs

precompiled/x86_64-unknown-linux-gnu/src/lib.rs

@@ -0,0 +1,213 @@
+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::{Read, Write};
+use std::iter::FromIterator;
+use std::process::{Command, Stdio};
+use std::str::FromStr;
+
+#[cfg(not(all(target_arch = "x86_64", target_os = "linux", target_env = "gnu")))]
+compile_error! {
+    "this proof of concept is only compiled for x86_64-unknown-linux-gnu"
+}
+
+#[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, 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 mut child = Command::new(concat!(env!("CARGO_MANIFEST_DIR"), "/serde_derive"))
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .spawn()
+        .expect("failed to spawn process");
+
+    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 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 {
+    // Depth-first post-order traversal.
+    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 = 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())] // FIXME
+            return span.join(self.spans[hi as usize]).unwrap_or(span);
+            span
+        }
+    }
+}

serde_derive/src/lib.rs

@@ -68,9 +68,13 @@ extern crate quote;
 #[macro_use]
 extern crate syn;
 
+#[cfg(not(precompiled))]
 extern crate proc_macro;
 extern crate proc_macro2;
 
+#[cfg(precompiled)]
+extern crate proc_macro2 as proc_macro;
+
 mod internals;
 
 use proc_macro::TokenStream;
@@ -88,7 +92,17 @@ mod ser;
 mod this;
 mod try;
 
-#[proc_macro_derive(Serialize, attributes(serde))]
+#[cfg(precompiled)]
+macro_rules! parse_macro_input {
+    ($tokenstream:ident as $ty:ty) => {
+        match syn::parse2::<$ty>($tokenstream) {
+            Ok(data) => data,
+            Err(err) => return err.to_compile_error(),
+        }
+    };
+}
+
+#[cfg_attr(not(precompiled), proc_macro_derive(Serialize, attributes(serde)))]
 pub fn derive_serialize(input: TokenStream) -> TokenStream {
     let mut input = parse_macro_input!(input as DeriveInput);
     ser::expand_derive_serialize(&mut input)
@@ -96,7 +110,7 @@ pub fn derive_serialize(input: TokenStream) -> TokenStream {
         .into()
 }
 
-#[proc_macro_derive(Deserialize, attributes(serde))]
+#[cfg_attr(not(precompiled), proc_macro_derive(Deserialize, attributes(serde)))]
 pub fn derive_deserialize(input: TokenStream) -> TokenStream {
     let mut input = parse_macro_input!(input as DeriveInput);
     de::expand_derive_deserialize(&mut input)