Correct style of comments

src/helpers.rs

@@ -291,6 +291,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             }
         }
     }
+
     /// Helper function to get a `libc` constant as a `Scalar`.
     fn eval_libc(&mut self, name: &str) -> InterpResult<'tcx, Scalar<Tag>> {
         self.eval_context_mut()
@@ -298,6 +299,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             .ok_or_else(|| err_unsup_format!("Path libc::{} cannot be resolved.", name).into())
             .and_then(|scalar| scalar.not_undef())
     }
+
     /// Helper function to get a `libc` constant as an `i32`.
     fn eval_libc_i32(&mut self, name: &str) -> InterpResult<'tcx, i32> {
         self.eval_libc(name).and_then(|scalar| scalar.to_i32())

src/shims/env.rs

@@ -133,9 +133,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             Ok(cwd) => {
                 // It is not clear what happens with non-utf8 paths here
                 let mut bytes = cwd.display().to_string().into_bytes();
-                // If `size` is smaller or equal than the `bytes.len()`, writing `bytes` using the
-                // `buf` pointer would cause an overflow, the desired behavior in this case is to
-                // return null.
+                // If `size` is smaller or equal than the `bytes.len()`, writing `bytes` plus the
+                // required null terminator to memory using the `buf` pointer would cause an
+                // overflow, the desired behavior in this case is to return null.
                 if (bytes.len() as u64) < size {
                     // We add a `/0` terminator
                     bytes.push(0);

tests/run-pass/current_dir.rs

@@ -4,14 +4,14 @@ use std::env;
 use std::path::Path;
 
 fn main() {
-    // test that `getcwd` is available
+    // Test that `getcwd` is available
     let cwd = env::current_dir().unwrap();
-    // test that changing dir to `..` actually sets the current directory to the parent of `cwd`.
-    // the only exception here is if `cwd` is the root directory, then changing directory must
+    // Test that changing dir to `..` actually sets the current directory to the parent of `cwd`.
+    // The only exception here is if `cwd` is the root directory, then changing directory must
     // keep the current directory equal to `cwd`.
     let parent = cwd.parent().unwrap_or(&cwd);
-    // test that `chdir` is available
+    // Test that `chdir` is available
     assert!(env::set_current_dir(&Path::new("..")).is_ok());
-    // test that `..` goes to the parent directory
+    // Test that `..` goes to the parent directory
     assert_eq!(env::current_dir().unwrap(), parent);
 }