From dadcb0550d41c343988310ee1946d8dd8f477008 Mon Sep 17 00:00:00 2001
From: Joshua Nelson <jyn514@gmail.com>
Date: Sat, 1 May 2021 01:56:52 -0400
Subject: [PATCH] Allow formatting specific subdirectories

---
 src/bootstrap/flags.rs  |  3 ++-
 src/bootstrap/format.rs | 17 ++++++++++++++---
 src/bootstrap/lib.rs    |  4 ++--
 src/bootstrap/test.rs   |  2 +-
 4 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/bootstrap/flags.rs b/src/bootstrap/flags.rs
index 6044899c237e2..c7034dfeaabd7 100644
--- a/src/bootstrap/flags.rs
+++ b/src/bootstrap/flags.rs
@@ -91,6 +91,7 @@ pub enum Subcommand {
         paths: Vec<PathBuf>,
     },
     Format {
+        paths: Vec<PathBuf>,
         check: bool,
     },
     Doc {
@@ -578,7 +579,7 @@ Arguments:
 
                 Subcommand::Clean { all: matches.opt_present("all") }
             }
-            "fmt" => Subcommand::Format { check: matches.opt_present("check") },
+            "fmt" => Subcommand::Format { check: matches.opt_present("check"), paths },
             "dist" => Subcommand::Dist { paths },
             "install" => Subcommand::Install { paths },
             "run" | "r" => {
diff --git a/src/bootstrap/format.rs b/src/bootstrap/format.rs
index d21e3408144fe..2408344487bb1 100644
--- a/src/bootstrap/format.rs
+++ b/src/bootstrap/format.rs
@@ -42,7 +42,7 @@ struct RustfmtConfig {
     ignore: Vec<String>,
 }
 
-pub fn format(build: &Build, check: bool) {
+pub fn format(build: &Build, check: bool, paths: &[PathBuf]) {
     if build.config.dry_run {
         return;
     }
@@ -118,8 +118,19 @@ pub fn format(build: &Build, check: bool) {
         .to_path_buf();
     let src = build.src.clone();
     let (tx, rx): (SyncSender<PathBuf>, _) = std::sync::mpsc::sync_channel(128);
-    let walker =
-        WalkBuilder::new(src.clone()).types(matcher).overrides(ignore_fmt).build_parallel();
+    let walker = match paths.get(0) {
+        Some(first) => {
+            let mut walker = WalkBuilder::new(first);
+            for path in &paths[1..] {
+                walker.add(path);
+            }
+            walker
+        }
+        None => WalkBuilder::new(src.clone()),
+    }
+    .types(matcher)
+    .overrides(ignore_fmt)
+    .build_parallel();
 
     // there is a lot of blocking involved in spawning a child process and reading files to format.
     // spawn more processes than available concurrency to keep the CPU busy
diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index 24da44b933abc..2960dd3df6bf4 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -478,8 +478,8 @@ impl Build {
             job::setup(self);
         }
 
-        if let Subcommand::Format { check } = self.config.cmd {
-            return format::format(self, check);
+        if let Subcommand::Format { check, paths } = &self.config.cmd {
+            return format::format(self, *check, &paths);
         }
 
         if let Subcommand::Clean { all } = self.config.cmd {
diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index 965d11621450b..a115ea905aa72 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -897,7 +897,7 @@ help: to skip test's attempt to check tidiness, pass `--exclude src/tools/tidy`
                 );
                 std::process::exit(1);
             }
-            crate::format::format(&builder.build, !builder.config.cmd.bless());
+            crate::format::format(&builder.build, !builder.config.cmd.bless(), &[]);
         }
     }