Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

vendor/syn/benches/file.rs

@@ -0,0 +1,57 @@
+// $ cargo bench --features full,test --bench file
+
+#![feature(rustc_private, test)]
+#![recursion_limit = "1024"]
+#![allow(
+    clippy::items_after_statements,
+    clippy::manual_let_else,
+    clippy::match_like_matches_macro,
+    clippy::missing_panics_doc,
+    clippy::must_use_candidate,
+    clippy::uninlined_format_args
+)]
+
+extern crate test;
+
+#[macro_use]
+#[path = "../tests/macros/mod.rs"]
+mod macros;
+
+#[allow(dead_code)]
+#[path = "../tests/repo/mod.rs"]
+mod repo;
+
+use proc_macro2::{Span, TokenStream};
+use std::fs;
+use std::str::FromStr;
+use syn::parse::{ParseStream, Parser};
+use test::Bencher;
+
+const FILE: &str = "tests/rust/library/core/src/str/mod.rs";
+
+fn get_tokens() -> TokenStream {
+    repo::clone_rust();
+    let content = fs::read_to_string(FILE).unwrap();
+    TokenStream::from_str(&content).unwrap()
+}
+
+#[bench]
+fn baseline(b: &mut Bencher) {
+    let tokens = get_tokens();
+    b.iter(|| drop(tokens.clone()));
+}
+
+#[bench]
+fn create_token_buffer(b: &mut Bencher) {
+    let tokens = get_tokens();
+    fn immediate_fail(_input: ParseStream) -> syn::Result<()> {
+        Err(syn::Error::new(Span::call_site(), ""))
+    }
+    b.iter(|| immediate_fail.parse2(tokens.clone()));
+}
+
+#[bench]
+fn parse_file(b: &mut Bencher) {
+    let tokens = get_tokens();
+    b.iter(|| syn::parse2::<syn::File>(tokens.clone()));
+}

vendor/syn/benches/rust.rs

@@ -0,0 +1,182 @@
+// $ cargo bench --features full,test --bench rust
+//
+// Syn only, useful for profiling:
+// $ RUSTFLAGS='--cfg syn_only' cargo build --release --features full,test --bench rust
+
+#![cfg_attr(not(syn_only), feature(rustc_private))]
+#![recursion_limit = "1024"]
+#![allow(
+    clippy::arc_with_non_send_sync,
+    clippy::cast_lossless,
+    clippy::let_underscore_untyped,
+    clippy::manual_let_else,
+    clippy::match_like_matches_macro,
+    clippy::uninlined_format_args,
+    clippy::unnecessary_wraps
+)]
+
+#[macro_use]
+#[path = "../tests/macros/mod.rs"]
+mod macros;
+
+#[allow(dead_code)]
+#[path = "../tests/repo/mod.rs"]
+mod repo;
+
+use std::fs;
+use std::time::{Duration, Instant};
+
+#[cfg(not(syn_only))]
+mod tokenstream_parse {
+    use proc_macro2::TokenStream;
+    use std::str::FromStr;
+
+    pub fn bench(content: &str) -> Result<(), ()> {
+        TokenStream::from_str(content).map(drop).map_err(drop)
+    }
+}
+
+mod syn_parse {
+    pub fn bench(content: &str) -> Result<(), ()> {
+        syn::parse_file(content).map(drop).map_err(drop)
+    }
+}
+
+#[cfg(not(syn_only))]
+mod librustc_parse {
+    extern crate rustc_data_structures;
+    extern crate rustc_driver;
+    extern crate rustc_error_messages;
+    extern crate rustc_errors;
+    extern crate rustc_parse;
+    extern crate rustc_session;
+    extern crate rustc_span;
+
+    use rustc_data_structures::sync::Lrc;
+    use rustc_error_messages::FluentBundle;
+    use rustc_errors::{emitter::Emitter, translation::Translate, DiagCtxt, Diagnostic};
+    use rustc_session::parse::ParseSess;
+    use rustc_span::source_map::{FilePathMapping, SourceMap};
+    use rustc_span::{edition::Edition, FileName};
+
+    pub fn bench(content: &str) -> Result<(), ()> {
+        struct SilentEmitter;
+
+        impl Emitter for SilentEmitter {
+            fn emit_diagnostic(&mut self, _diag: &Diagnostic) {}
+            fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+                None
+            }
+        }
+
+        impl Translate for SilentEmitter {
+            fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
+                None
+            }
+            fn fallback_fluent_bundle(&self) -> &FluentBundle {
+                panic!("silent emitter attempted to translate a diagnostic");
+            }
+        }
+
+        rustc_span::create_session_if_not_set_then(Edition::Edition2018, |_| {
+            let source_map = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+            let emitter = Box::new(SilentEmitter);
+            let handler = DiagCtxt::with_emitter(emitter);
+            let sess = ParseSess::with_dcx(handler, source_map);
+            if let Err(diagnostic) = rustc_parse::parse_crate_from_source_str(
+                FileName::Custom("bench".to_owned()),
+                content.to_owned(),
+                &sess,
+            ) {
+                diagnostic.cancel();
+                return Err(());
+            };
+            Ok(())
+        })
+    }
+}
+
+#[cfg(not(syn_only))]
+mod read_from_disk {
+    pub fn bench(content: &str) -> Result<(), ()> {
+        let _ = content;
+        Ok(())
+    }
+}
+
+fn exec(mut codepath: impl FnMut(&str) -> Result<(), ()>) -> Duration {
+    let begin = Instant::now();
+    let mut success = 0;
+    let mut total = 0;
+
+    ["tests/rust/compiler", "tests/rust/library"]
+        .iter()
+        .flat_map(|dir| {
+            walkdir::WalkDir::new(dir)
+                .into_iter()
+                .filter_entry(repo::base_dir_filter)
+        })
+        .for_each(|entry| {
+            let entry = entry.unwrap();
+            let path = entry.path();
+            if path.is_dir() {
+                return;
+            }
+            let content = fs::read_to_string(path).unwrap();
+            let ok = codepath(&content).is_ok();
+            success += ok as usize;
+            total += 1;
+            if !ok {
+                eprintln!("FAIL {}", path.display());
+            }
+        });
+
+    assert_eq!(success, total);
+    begin.elapsed()
+}
+
+fn main() {
+    repo::clone_rust();
+
+    macro_rules! testcases {
+        ($($(#[$cfg:meta])* $name:ident,)*) => {
+            [
+                $(
+                    $(#[$cfg])*
+                    (stringify!($name), $name::bench as fn(&str) -> Result<(), ()>),
+                )*
+            ]
+        };
+    }
+
+    #[cfg(not(syn_only))]
+    {
+        let mut lines = 0;
+        let mut files = 0;
+        exec(|content| {
+            lines += content.lines().count();
+            files += 1;
+            Ok(())
+        });
+        eprintln!("\n{} lines in {} files", lines, files);
+    }
+
+    for (name, f) in testcases!(
+        #[cfg(not(syn_only))]
+        read_from_disk,
+        #[cfg(not(syn_only))]
+        tokenstream_parse,
+        syn_parse,
+        #[cfg(not(syn_only))]
+        librustc_parse,
+    ) {
+        eprint!("{:20}", format!("{}:", name));
+        let elapsed = exec(f);
+        eprintln!(
+            "elapsed={}.{:03}s",
+            elapsed.as_secs(),
+            elapsed.subsec_millis(),
+        );
+    }
+    eprintln!();
+}