feature: add derive macro for auto-CharDevice

kernel/macros/src/lib.rs

@@ -0,0 +1,38 @@
+extern crate proc_macro;
+extern crate syn;
+#[macro_use]
+extern crate quote;
+
+use proc_macro::TokenStream;
+use syn::{parse_macro_input, DeriveInput};
+
+#[proc_macro_derive(TtyCharDevice)]
+pub fn derive_tty_char_device(input: TokenStream) -> TokenStream {
+    let ast = parse_macro_input!(input as DeriveInput);
+
+    if !ast.generics.params.is_empty() {
+        panic!(
+            "Derived TtyCharDevice cannot have generic parameters: {:?}",
+            ast.ident
+        );
+    }
+    let ident = ast.ident;
+
+    quote! {
+        impl vfs::CharDevice for #ident {
+            fn read(&self, blocking: bool, data: &mut [u8]) -> Result<usize, libsys::error::Errno> {
+                assert!(blocking);
+                crate::dev::tty::TtyDevice::line_read(self, data)
+            }
+            fn write(&self, blocking: bool, data: &[u8]) -> Result<usize, libsys::error::Errno> {
+                assert!(blocking);
+                crate::dev::tty::TtyDevice::line_write(self, data)
+            }
+            fn ioctl(&self, cmd: libsys::ioctl::IoctlCmd, ptr: usize, len: usize) ->
+                Result<usize, libsys::error::Errno>
+            {
+                crate::dev::tty::TtyDevice::tty_ioctl(self, cmd, ptr, len)
+            }
+        }
+    }.into()
+}