1 files changed, 158 insertions, 0 deletions
diff --git a/syn/benches/rust.rs b/syn/benches/rust.rs
new file mode 100644
index 0000000..941ecb9
--- /dev/null
+++ b/syn/benches/rust.rs
@@ -0,0 +1,158 @@
+// $ cargo bench --features full --bench rust
+//
+// Syn only, useful for profiling:
+// $ RUSTFLAGS='--cfg syn_only' cargo build --release --features full --bench rust
+
+#![cfg_attr(not(syn_only), feature(rustc_private))]
+#![recursion_limit = "1024"]
+
+#[macro_use]
+#[path = "../tests/macros/mod.rs"]
+mod macros;
+
+#[path = "../tests/common/mod.rs"]
+mod common;
+#[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 libsyntax_parse {
+    extern crate rustc_data_structures;
+    extern crate rustc_parse;
+    extern crate rustc_span;
+    extern crate syntax;
+
+    use rustc_data_structures::sync::Lrc;
+    use rustc_span::FileName;
+    use syntax::edition::Edition;
+    use syntax::errors::{emitter::Emitter, Diagnostic, Handler};
+    use syntax::sess::ParseSess;
+    use syntax::source_map::{FilePathMapping, SourceMap};
+
+    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
+            }
+        }
+
+        syntax::with_globals(Edition::Edition2018, || {
+            let cm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
+            let emitter = Box::new(SilentEmitter);
+            let handler = Handler::with_emitter(false, None, emitter);
+            let sess = ParseSess::with_span_handler(handler, cm);
+            if let Err(mut 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;
+
+    walkdir::WalkDir::new("tests/rust/src")
+        .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:path,)*) => {
+            vec![
+                $(
+                    $(#[$cfg])*
+                    (stringify!($name), $name 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::bench,
+        #[cfg(not(syn_only))]
+        tokenstream_parse::bench,
+        syn_parse::bench,
+        #[cfg(not(syn_only))]
+        libsyntax_parse::bench,
+    ) {
+        eprint!("{:20}", format!("{}:", name));
+        let elapsed = exec(f);
+        eprintln!(
+            "elapsed={}.{:03}s",
+            elapsed.as_secs(),
+            elapsed.subsec_millis(),
+        );
+    }
+    eprintln!();
+}