Remove most files from format ignore list

Also moves formatting to use edition 2018, and to be done in parallel.
This brings near-linear speed ups (at least with a small amount of
cores).

Author: Mark-Simulacrum

rustfmt.toml

@@ -1,74 +1,59 @@
-# Currently, most of the code in the compiler uses historical style.
-#
-# For new code, consider running rustfmt with this config (it should
-# be picked up automatically).
+# Run rustfmt with this config (it should be picked up automatically).
 version = "Two"
 use_small_heuristics = "Max"
+merge_derives = false
 
 # by default we ignore everything in the repository
 # tidy only checks files which are not ignored, each entry follows gitignore style
 ignore = [
-    # remove directories below, or opt out their subdirectories, as they are formatted
-    "src/bootstrap/",
-    "src/build_helper/",
-    "src/liballoc/",
-    "src/libarena/",
-    "src/libcore/",
-    "src/libfmt_macros/",
-    "src/libgraphviz/",
-    "src/libpanic_abort/",
-    "src/libpanic_unwind/",
-    "src/libproc_macro/",
-    "src/libprofiler_builtins/",
-    "src/librustc/",
-    "src/librustc_apfloat/",
-    "src/librustc_asan/",
-    "src/librustc_codegen_llvm/",
-    "src/librustc_codegen_ssa/",
-    "src/librustc_codegen_utils/",
-    "src/librustc_data_structures/",
-    "src/librustc_driver/",
-    "src/librustc_errors/",
-    "src/librustc_feature/",
-    "src/librustc_incremental/",
-    "src/librustc_index/",
-    "src/librustc_interface/",
-    "src/librustc_lexer/",
-    "src/librustc_lint/",
-    "src/librustc_llvm/",
-    "src/librustc_lsan/",
-    "src/librustc_macros/",
-    "src/librustc_metadata/",
-    "src/librustc_mir/",
-    "src/librustc_msan/",
-    "src/librustc_parse/",
-    "src/librustc_passes/",
-    "src/librustc_plugin/",
-    "src/librustc_plugin_impl/",
-    "src/librustc_privacy/",
-    "src/librustc_resolve/",
-    "src/librustc_save_analysis/",
-    "src/librustc_session/",
-    "src/librustc_target/",
-    "src/librustc_traits/",
-    "src/librustc_tsan/",
-    "src/librustc_typeck/",
-    "src/librustdoc/",
-    "src/libserialize/",
-    "src/libstd/",
-    "src/libsyntax/",
-    "src/libsyntax_expand/",
-    "src/libsyntax_ext/",
-    "src/libsyntax_pos/",
-    "src/libterm/",
-    "src/libtest/",
-    "src/libunwind/",
-    "src/rtstartup/",
-    "src/rustc/",
-    "src/rustllvm/",
-    "src/test/",
-    "src/tools/",
-    "src/etc",
+    # tests for now are not formatted, as they are sometimes pretty-printing constrained
+    # (and generally rustfmt can move around comments in UI-testing incompatible ways)
+    "src/test",
+
+    # tidy issues (line length, etc.)
+    # to be fixed shortly
+    "src/libcore/iter/adapters/mod.rs",
+    "src/libcore/iter/traits/iterator.rs",
+    "src/librustc/hir/lowering.rs",
+    "src/librustc/infer/error_reporting/nice_region_error/outlives_closure.rs",
+    "src/librustc/lint/mod.rs",
+    "src/librustc/middle/resolve_lifetime.rs",
+    "src/librustc/traits/mod.rs",
+    "src/librustc/ty/constness.rs",
+    "src/librustc/ty/context.rs",
+    "src/librustc/ty/wf.rs",
+    "src/librustc_codegen_llvm/back/write.rs",
+    "src/librustc_codegen_llvm/consts.rs",
+    "src/librustc_codegen_llvm/debuginfo/metadata.rs",
+    "src/librustc_codegen_ssa/base.rs",
+    "src/librustc_codegen_ssa/mir/place.rs",
+    "src/librustc_codegen_utils/symbol_names/v0.rs",
+    "src/librustc_errors/emitter.rs",
+    "src/librustc_mir/borrow_check/diagnostics/mutability_errors.rs",
+    "src/librustc_mir/borrow_check/type_check/mod.rs",
+    "src/librustc_mir/build/expr/as_rvalue.rs",
+    "src/librustc_mir/build/matches/mod.rs",
+    "src/librustc_mir/build/mod.rs",
+    "src/librustc_mir/const_eval.rs",
+    "src/librustc_mir/interpret/place.rs",
+    "src/librustc_mir/monomorphize/collector.rs",
+    "src/librustc_passes/ast_validation.rs",
+    "src/librustc_resolve/lib.rs",
+    "src/librustc_resolve/resolve_imports.rs",
+    "src/librustc_typeck/astconv.rs",
+    "src/librustc_typeck/check/_match.rs",
+    "src/librustc_typeck/check/coercion.rs",
+    "src/librustc_typeck/check/method/confirm.rs",
+    "src/librustc_typeck/check/mod.rs",
+    "src/librustc_typeck/check/wfcheck.rs",
+    "src/librustdoc/html/markdown/tests.rs",
+    "src/libstd/sys/sgx/abi/mem.rs",
+    "src/libstd/sys/unix/os.rs",
+    "src/libsyntax_expand/parse/lexer/tests.rs",
+    "src/libsyntax_expand/parse/tests.rs",
+    "src/libsyntax_ext/test.rs",
+    "src/tools/build-manifest/src/main.rs",
+    "src/librustc_feature",
 
     # do not format submodules
     "src/doc/book",

src/bootstrap/format.rs

@@ -1,21 +1,17 @@
 //! Runs rustfmt on the repository.
 
 use crate::Build;
-use std::process::Command;
+use build_helper::t;
 use ignore::WalkBuilder;
 use std::path::Path;
-use build_helper::t;
-
-fn rustfmt(build: &Build, path: &Path, check: bool) {
-    let rustfmt_path = build.config.initial_rustfmt.as_ref().unwrap_or_else(|| {
-        eprintln!("./x.py fmt is not supported on this channel");
-        std::process::exit(1);
-    });
+use std::process::Command;
 
-    let mut cmd = Command::new(&rustfmt_path);
+fn rustfmt(src: &Path, rustfmt: &Path, path: &Path, check: bool) {
+    let mut cmd = Command::new(&rustfmt);
     // avoid the submodule config paths from coming into play,
     // we only allow a single global config for the workspace for now
-    cmd.arg("--config-path").arg(&build.src.canonicalize().unwrap());
+    cmd.arg("--config-path").arg(&src.canonicalize().unwrap());
+    cmd.arg("--edition").arg("2018");
     cmd.arg("--unstable-features");
     cmd.arg("--skip-children");
     if check {
@@ -51,14 +47,21 @@ pub fn format(build: &Build, check: bool) {
     }
     let ignore_fmt = ignore_fmt.build().unwrap();
 
-    let walker = WalkBuilder::new(&build.src)
-        .types(matcher)
-        .overrides(ignore_fmt)
-        .build();
-    for entry in walker {
-        let entry = t!(entry);
-        if entry.file_type().map_or(false, |t| t.is_file()) {
-            rustfmt(build, &entry.path(), check);
-        }
-    }
+    let rustfmt_path = build.config.initial_rustfmt.as_ref().unwrap_or_else(|| {
+        eprintln!("./x.py fmt is not supported on this channel");
+        std::process::exit(1);
+    });
+    let src = build.src.clone();
+    let walker = WalkBuilder::new(&build.src).types(matcher).overrides(ignore_fmt).build_parallel();
+    walker.run(|| {
+        let src = src.clone();
+        let rustfmt_path = rustfmt_path.clone();
+        Box::new(move |entry| {
+            let entry = t!(entry);
+            if entry.file_type().map_or(false, |t| t.is_file()) {
+                rustfmt(&src, &rustfmt_path, &entry.path(), check);
+            }
+            ignore::WalkState::Continue
+        })
+    });
 }