Convert regular comments to documentation comments.

lib/filetests/src/concurrent.rs

@@ -13,7 +13,7 @@ use std::time::Duration;
 use num_cpus;
 use {TestResult, runone};
 
-// Request sent to worker threads contains jobid and path.
+/// Request sent to worker threads contains jobid and path.
 struct Request(usize, PathBuf);
 
 /// Reply from worker thread,
@@ -25,13 +25,13 @@ pub enum Reply {
 
 /// Manage threads that run test jobs concurrently.
 pub struct ConcurrentRunner {
-    // Channel for sending requests to the worker threads.
-    // The workers are sharing the receiver with an `Arc<Mutex<Receiver>>`.
-    // This is `None` when shutting down.
+    /// Channel for sending requests to the worker threads.
+    /// The workers are sharing the receiver with an `Arc<Mutex<Receiver>>`.
+    /// This is `None` when shutting down.
     request_tx: Option<Sender<Request>>,
 
-    // Channel for receiving replies from the workers.
-    // Workers have their own `Sender`.
+    /// Channel for receiving replies from the workers.
+    /// Workers have their own `Sender`.
     reply_rx: Receiver<Reply>,
 
     handles: Vec<thread::JoinHandle<timing::PassTimes>>,

lib/filetests/src/runner.rs

@@ -11,10 +11,10 @@ use std::time;
 use {TestResult, runone};
 use concurrent::{ConcurrentRunner, Reply};
 
-// Timeout in seconds when we're not making progress.
+/// Timeout in seconds when we're not making progress.
 const TIMEOUT_PANIC: usize = 10;
 
-// Timeout for reporting slow tests without panicking.
+/// Timeout for reporting slow tests without panicking.
 const TIMEOUT_SLOW: usize = 3;
 
 struct QueueEntry {

lib/filetests/src/test_binemit.rs

@@ -27,7 +27,7 @@ pub fn subtest(parsed: &TestCommand) -> Result<Box<SubTest>> {
     }
 }
 
-// Code sink that generates text.
+/// Code sink that generates text.
 struct TextSink {
     offset: binemit::CodeOffset,
     text: String,

lib/filetests/src/test_compile.rs

@@ -76,7 +76,7 @@ impl SubTest for TestCompile {
     }
 }
 
-// Code sink that simply counts bytes.
+/// Code sink that simply counts bytes.
 struct SizeSink {
     offset: binemit::CodeOffset,
 }