third_party_rust_syn/tests/test_round_trip.rs

// Copyright 2018 Syn Developers
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#![cfg(feature = "full")]
#![feature(rustc_private)]

#[macro_use]
extern crate quote;
extern crate rayon;
extern crate syn;
extern crate syntax;
extern crate syntax_pos;
extern crate walkdir;

use rayon::iter::{IntoParallelIterator, ParallelIterator};
use syntax::ast;
use syntax::parse::{self, PResult, ParseSess};
use syntax::codemap::FilePathMapping;
use syntax_pos::FileName;
use walkdir::{DirEntry, WalkDir, WalkDirIterator};

use std::fs::File;
use std::io::Read;
use std::panic;
use std::process;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::time::Instant;

#[macro_use]
mod macros;

#[allow(dead_code)]
mod common;

#[test]
fn test_round_trip() {
    common::check_min_stack();
    common::clone_rust();
    let abort_after = common::abort_after();
    if abort_after == 0 {
        panic!("Skipping all round_trip tests");
    }

    let failed = AtomicUsize::new(0);

    WalkDir::new("tests/rust")
        .sort_by(|a, b| a.cmp(b))
        .into_iter()
        .filter_entry(common::base_dir_filter)
        .collect::<Result<Vec<DirEntry>, walkdir::Error>>()
        .unwrap()
        .into_par_iter()
        .for_each(|entry| {
            let path = entry.path();
            if path.is_dir() {
                return;
            }

            let mut file = File::open(path).unwrap();
            let mut content = String::new();
            file.read_to_string(&mut content).unwrap();

            let start = Instant::now();
            let (krate, elapsed) = match syn::parse_file(&content) {
                Ok(krate) => (krate, start.elapsed()),
                Err(msg) => {
                    errorf!("=== {}: syn failed to parse\n{:?}\n", path.display(), msg);
                    let prev_failed = failed.fetch_add(1, Ordering::SeqCst);
                    if prev_failed + 1 >= abort_after {
                        process::exit(1);
                    }
                    return;
                }
            };
            let back = quote!(#krate).to_string();

            let equal = panic::catch_unwind(|| {
                let sess = ParseSess::new(FilePathMapping::empty());
                let before = match libsyntax_parse(content, &sess) {
                    Ok(before) => before,
                    Err(mut diagnostic) => {
                        diagnostic.cancel();
                        if diagnostic
                            .message()
                            .starts_with("file not found for module")
                        {
                            errorf!("=== {}: ignore\n", path.display());
                        } else {
                            errorf!(
                                "=== {}: ignore - libsyntax failed to parse original content: {}\n",
                                path.display(),
                                diagnostic.message()
                            );
                        }
                        return true;
                    }
                };
                let after = match libsyntax_parse(back, &sess) {
                    Ok(after) => after,
                    Err(mut diagnostic) => {
                        errorf!("=== {}: libsyntax failed to parse", path.display());
                        diagnostic.emit();
                        return false;
                    }
                };

                if before == after {
                    errorf!(
                        "=== {}: pass in {}ms\n",
                        path.display(),
                        elapsed.as_secs() * 1000 + u64::from(elapsed.subsec_nanos()) / 1_000_000
                    );
                    true
                } else {
                    errorf!(
                        "=== {}: FAIL\nbefore: {}\nafter: {}\n",
                        path.display(),
                        format!("{:?}", before).replace("\n", ""),
                        format!("{:?}", after).replace("\n", "")
                    );
                    false
                }
            });
            match equal {
                Err(_) => errorf!("=== {}: ignoring libsyntax panic\n", path.display()),
                Ok(true) => {}
                Ok(false) => {
                    let prev_failed = failed.fetch_add(1, Ordering::SeqCst);
                    if prev_failed + 1 >= abort_after {
                        process::exit(1);
                    }
                }
            }
        });

    let failed = failed.load(Ordering::SeqCst);
    if failed > 0 {
        panic!("{} failures", failed);
    }
}

fn libsyntax_parse(content: String, sess: &ParseSess) -> PResult<ast::Crate> {
    let name = FileName::Custom("test_round_trip".to_string());
    parse::parse_crate_from_source_str(name, content, sess).map(common::respan::respan_crate)
}