More comments.

Author: sunfishcode

c-scape/src/jmp.rs

@@ -1,3 +1,11 @@
+//! Setjmp and longjmp.
+//!
+//! It's not possible to call these functions from Rust code, because Rust
+//! lacks a "returns twice" attribute, which would be needed to describe the
+//! behavior of `setjmp` and `sigsetjmp`. However, it may be possible to
+//! call them from C code that links to c-scape via its C ABI. All of the
+//! magic is hidden in inside `naked_asm` blocks.
+
 use core::arch::naked_asm;
 use core::mem::size_of;
 use libc::{c_int, c_void};

c-scape/src/nss.rs

@@ -1,7 +1,7 @@
 //! Most of the nss functions are implement in c-gull rather than c-scape.
 //! But we provide a `getpwuid_r` stub definition here in no-std mode because
 //! it's referenced by libstd. libstd doesn't use it for anything other than
-//! a fallback for when the HOME environment variable is unsed, and HOME is
+//! a fallback for when the HOME environment variable is unset, and HOME is
 //! set in any reasonable use case where this would be called, so a stub
 //! suffices.
 

c-scape/src/todo/set_id.rs

@@ -3,7 +3,7 @@
 //!
 //! This would typically entail taking a lock that prevents thread creation,
 //! setting the IDs for each thread manually by sending signals to them and
-//! having signal handlers that perform the set operation, waitinig for all
+//! having signal handlers that perform the set operation, waiting for all
 //! the handlers to run, and then releasing the lock.
 
 #[no_mangle]