Add some comments, and minor cleanups. (#118)

Author: sunfishcode

c-gull/src/lib.rs

@@ -1,7 +1,6 @@
 #![doc = include_str!("../README.md")]
-#![feature(strict_provenance)]
-#![feature(c_variadic)]
 #![feature(sync_unsafe_cell)]
+#![feature(strict_provenance)]
 #![deny(fuzzy_provenance_casts, lossy_provenance_casts)]
 #![cfg_attr(not(feature = "std"), no_std)]
 

c-gull/src/termios_.rs

@@ -1,4 +1,8 @@
 //! Termios APIs
+//!
+//! Most of the termios functions are in c-scape, but ttyname is in c-gull
+//! because it depends on rustix's procfs feature, which depends on std. Rustix
+//! could be changed to avoid using std here, if it becomes important.
 
 use crate::convert_res;
 use alloc::ffi::CString;

c-scape/empty/README.md

@@ -1,3 +1,3 @@
 This directory contains empty static libraries such as libc.a, libm.a, and
 others, to prevent the linker from opening the platform's version of those
-libraries.
+libraries, when we're in "take charge" mode.

c-scape/src/math/mod.rs

@@ -799,8 +799,8 @@ mod complex;
 
 #[cfg(test)]
 mod tests {
-
     use super::*;
+
     #[test]
     fn is_finite_test() {
         unsafe {

c-scape/src/nss.rs

@@ -1,3 +1,10 @@
+//! 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
+//! set in any reasonable use case where this would be called, so a stub
+//! suffices.
+
 #[cfg(not(feature = "std"))]
 #[cfg(not(target_os = "wasi"))]
 use libc::{c_char, c_int, passwd, uid_t};

c-scape/src/thread/mod.rs

@@ -970,7 +970,7 @@ unsafe extern "C" fn __tls_get_addr(p: &[usize; 2]) -> *mut c_void {
     //libc!(libc::__tls_get_addr(p));
     let [module, offset] = *p;
     // Offset 0 is the generation field, and we don't support dynamic linking,
-    // so we should only sever see 1 here.
+    // so we should only ever see 1 here.
     assert_eq!(module, 1);
     thread::current_tls_addr(offset)
 }