Remove dependence on rustc/rustc_driver, use syntex

Instead just parse manually with the `syntex_syntax` crate which is a clone of
libsyntax on crates.io which builds on stable Rust.

Cargo.lock

@@ -8,6 +8,7 @@ dependencies = [
  "regex 0.1.41 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "strings 0.0.1 (git+https://github.com/nrc/strings.rs.git)",
+ "syntex_syntax 0.18.0 (git+https://github.com/serde-rs/syntex)",
  "term 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "toml 0.1.23 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-segmentation 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -21,6 +22,11 @@ dependencies = [
  "memchr 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "bitflags"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "diff"
 version = "0.1.7"
@@ -93,6 +99,19 @@ dependencies = [
  "log 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "syntex_syntax"
+version = "0.18.0"
+source = "git+https://github.com/serde-rs/syntex#176ca5d8add606fac8d503b10c89ddb82f02d92b"
+dependencies = [
+ "bitflags 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-serialize 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "term 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "unicode-xid 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "term"
 version = "0.2.12"
@@ -115,6 +134,11 @@ name = "unicode-segmentation"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "unicode-xid"
+version = "0.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "winapi"
 version = "0.2.4"

Cargo.toml

@@ -16,6 +16,7 @@ regex = "0.1.41"
 term = "0.2.11"
 strings = { version = "0.0.1", git = "https://github.com/nrc/strings.rs.git" }
 diff = { git = "https://github.com/utkarshkukreti/diff.rs.git" }
+syntex_syntax = { git = "https://github.com/serde-rs/syntex" }
 log = "0.3.2"
 env_logger = "0.3.1"
 

src/lib.rs

@@ -15,10 +15,7 @@
 #[macro_use]
 extern crate log;
 
-extern crate getopts;
-extern crate rustc;
-extern crate rustc_driver;
-extern crate syntax;
+extern crate syntex_syntax as syntax;
 extern crate rustc_serialize;
 
 extern crate strings;
@@ -28,22 +25,15 @@ extern crate regex;
 extern crate diff;
 extern crate term;
 
-use rustc::session::Session;
-use rustc::session::config as rustc_config;
-use rustc::session::config::Input;
-use rustc_driver::{driver, CompilerCalls, Compilation};
-
 use syntax::ast;
 use syntax::codemap::{CodeMap, Span};
-use syntax::diagnostics;
+use syntax::parse::{self, ParseSess};
 
 use std::ops::{Add, Sub};
-use std::path::PathBuf;
+use std::path::Path;
 use std::collections::HashMap;
 use std::fmt;
 use std::str::FromStr;
-use std::rc::Rc;
-use std::cell::RefCell;
 
 use issues::{BadIssueSeeker, Issue};
 use filemap::FileMap;
@@ -380,65 +370,24 @@ pub fn fmt_lines(file_map: &mut FileMap, config: &Config) -> FormatReport {
     report
 }
 
-struct RustFmtCalls {
-    config: Rc<Config>,
-    result: Rc<RefCell<Option<FileMap>>>,
-}
+pub fn format(file: &Path, config: &Config) -> FileMap {
+    let parse_session = ParseSess::new();
+    let krate = parse::parse_crate_from_file(file, Vec::new(), &parse_session);
+    let mut file_map = fmt_ast(&krate, parse_session.codemap(), config);
 
-impl<'a> CompilerCalls<'a> for RustFmtCalls {
-    fn no_input(&mut self,
-                _: &getopts::Matches,
-                _: &rustc_config::Options,
-                _: &Option<PathBuf>,
-                _: &Option<PathBuf>,
-                _: &diagnostics::registry::Registry)
-                -> Option<(Input, Option<PathBuf>)> {
-        panic!("No input supplied to RustFmt");
-    }
+    // For some reason, the codemap does not include terminating
+    // newlines so we must add one on for each file. This is sad.
+    filemap::append_newlines(&mut file_map);
 
-    fn build_controller(&mut self, _: &Session) -> driver::CompileController<'a> {
-        let result = self.result.clone();
-        let config = self.config.clone();
-
-        let mut control = driver::CompileController::basic();
-        control.after_parse.stop = Compilation::Stop;
-        control.after_parse.callback = Box::new(move |state| {
-            let krate = state.krate.unwrap();
-            let codemap = state.session.codemap();
-            let mut file_map = fmt_ast(krate, codemap, &*config);
-            // For some reason, the codemap does not include terminating
-            // newlines so we must add one on for each file. This is sad.
-            filemap::append_newlines(&mut file_map);
-
-            *result.borrow_mut() = Some(file_map);
-        });
-
-        control
-    }
-}
-
-pub fn format(args: Vec<String>, config: &Config) -> FileMap {
-    let result = Rc::new(RefCell::new(None));
-
-    {
-        let config = Rc::new(config.clone());
-        let mut call_ctxt = RustFmtCalls {
-            config: config,
-            result: result.clone(),
-        };
-        rustc_driver::run_compiler(&args, &mut call_ctxt);
-    }
-
-    // Peel the union.
-    Rc::try_unwrap(result).ok().unwrap().into_inner().unwrap()
+    return file_map;
 }
 
 // args are the arguments passed on the command line, generally passed through
 // to the compiler.
 // write_mode determines what happens to the result of running rustfmt, see
 // WriteMode.
-pub fn run(args: Vec<String>, write_mode: WriteMode, config: &Config) {
-    let mut result = format(args, config);
+pub fn run(file: &Path, write_mode: WriteMode, config: &Config) {
+    let mut result = format(file, config);
 
     println!("{}", fmt_lines(&mut result, config));
 

src/macros.rs

@@ -19,15 +19,10 @@
 // List-like invocations with parentheses will be formatted as function calls,
 // and those with brackets will be formatted as array literals.
 
-use std::thread;
-use std::collections::hash_map::{HashMap, Entry};
-
 use syntax::ast;
 use syntax::parse::token::{Eof, Comma, Token};
 use syntax::parse::{ParseSess, tts_to_parser};
 use syntax::codemap::{mk_sp, BytePos};
-use syntax::parse::token;
-use syntax::util::interner::StrInterner;
 
 use Indent;
 use rewrite::RewriteContext;
@@ -37,12 +32,6 @@ use utils::{wrap_str, span_after};
 
 static FORCED_BRACKET_MACROS: &'static [&'static str] = &["vec!"];
 
-// We need to pass `TokenTree`s to our expression parsing thread, but they are
-// not `Send`. We wrap them in a `Send` container to force our will.
-// FIXME: this is a pretty terrible hack. Any other solution would be preferred.
-struct ForceSend<T>(pub T);
-unsafe impl<T> Send for ForceSend<T> {}
-
 // FIXME: use the enum from libsyntax?
 #[derive(Clone, Copy)]
 enum MacroStyle {
@@ -84,38 +73,28 @@ pub fn rewrite_macro(mac: &ast::Mac,
         };
     }
 
-    let wrapped_tt_vec = ForceSend(mac.node.tts.clone());
-    let my_interner = ForceSend(clone_interner());
+    let parse_session = ParseSess::new();
+    let mut parser = tts_to_parser(&parse_session, mac.node.tts.clone(), Vec::new());
+    let mut expr_vec = Vec::new();
 
-    // Wrap expression parsing logic in a thread since the libsyntax parser
-    // panics on failure, which we do not want to propagate.
-    // The expression vector is wrapped in an Option inside a Result.
-    let expr_vec_result = thread::spawn(move || {
-        let parse_session = ParseSess::new();
-        let mut parser = tts_to_parser(&parse_session, wrapped_tt_vec.0, vec![]);
-        let mut expr_vec = vec![];
-        token::get_ident_interner().reset(my_interner.0);
+    loop {
+        expr_vec.push(match parser.parse_expr_nopanic() {
+            Ok(expr) => expr,
+            Err(..) => return None,
+        });
 
-        loop {
-            expr_vec.push(parser.parse_expr());
-
-            match parser.token {
-                Token::Eof => break,
-                Token::Comma => (),
-                _ => panic!("Macro not list-like, skiping..."),
-            }
-
-            let _ = parser.bump();
-
-            if parser.token == Token::Eof {
-                return None;
-            }
+        match parser.token {
+            Token::Eof => break,
+            Token::Comma => (),
+            _ => return None,
         }
 
-        Some(ForceSend((expr_vec, clone_interner())))
-    });
-    let (expr_vec, interner) = try_opt!(try_opt!(expr_vec_result.join().ok())).0;
-    token::get_ident_interner().reset(interner);
+        let _ = parser.bump();
+
+        if parser.token == Token::Eof {
+            return None;
+        }
+    }
 
     match style {
         MacroStyle::Parens => {
@@ -146,23 +125,6 @@ pub fn rewrite_macro(mac: &ast::Mac,
     }
 }
 
-fn clone_interner() -> StrInterner {
-    let old = token::get_ident_interner();
-    let new = StrInterner::new();
-    let mut map = HashMap::new();
-    for name in (0..old.len()).map(|i| i as u32).map(ast::Name) {
-        match map.entry(old.get(name)) {
-            Entry::Occupied(e) => {
-                new.gensym_copy(*e.get());
-            }
-            Entry::Vacant(e) => {
-                e.insert(new.intern(&old.get(name)));
-            }
-        }
-    }
-    return new
-}
-
 fn macro_style(mac: &ast::Mac, context: &RewriteContext) -> MacroStyle {
     let snippet = context.snippet(mac.span);
     let paren_pos = snippet.find_uncommented("(").unwrap_or(usize::max_value());

tests/system.rs

@@ -135,7 +135,6 @@ fn print_mismatches(result: HashMap<String, Vec<Mismatch>>) {
 pub fn idempotent_check(filename: String) -> Result<FormatReport, HashMap<String, Vec<Mismatch>>> {
     let sig_comments = read_significant_comments(&filename);
     let mut config = get_config(sig_comments.get("config").map(|x| &(*x)[..]));
-    let args = vec!["rustfmt".to_owned(), filename];
 
     for (key, val) in &sig_comments {
         if key != "target" && key != "config" {
@@ -146,7 +145,7 @@ pub fn idempotent_check(filename: String) -> Result<FormatReport, HashMap<String
     // Don't generate warnings for to-do items.
     config.report_todo = ReportTactic::Never;
 
-    let mut file_map = format(args, &config);
+    let mut file_map = format(Path::new(&filename), &config);
     let format_report = fmt_lines(&mut file_map, &config);
 
     // Won't panic, as we're not doing any IO.