feature: simple macro to auto-impl VnodeImpl items

Cargo.lock

@@ -64,6 +64,14 @@ dependencies = [
  "unsafe_unwrap",
 ]
 
+[[package]]
+name = "fs-macros"
+version = "0.1.0"
+dependencies = [
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "kernel"
 version = "0.1.0"
@@ -230,5 +238,6 @@ dependencies = [
 name = "vfs"
 version = "0.1.0"
 dependencies = [
+ "fs-macros",
  "libsys",
 ]

Cargo.toml

@@ -10,6 +10,7 @@ edition = "2018"
 [workspace]
 members = [
     "fs/fat32",
+    "fs/macros",
     "fs/memfs",
     "fs/vfs",
     "kernel",

fs/macros/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "fs-macros"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+syn = { version = "^1.0.81", features = ["full"] }
+quote = "^1.0.10"
+
+[lib]
+proc-macro = true

fs/macros/src/lib.rs

@@ -0,0 +1,119 @@
+extern crate proc_macro;
+extern crate syn;
+#[macro_use]
+extern crate quote;
+
+use proc_macro::TokenStream;
+use quote::ToTokens;
+use std::collections::HashSet;
+use syn::{parse_macro_input, ImplItem, ItemImpl, Ident};
+
+fn impl_inode_fn<T: ToTokens>(name: &str, behavior: T) -> ImplItem {
+    ImplItem::Verbatim(match name {
+        "create" => quote! {
+            fn create(&mut self, _at: VnodeRef, _name: &str, kind: VnodeKind) -> Result<VnodeRef, Errno> {
+                #behavior
+            }
+        },
+        "remove" => quote! {
+            fn remove(&mut self, _at: VnodeRef, _name: &str) -> Result<(), Errno> {
+                #behavior
+            }
+        },
+        "lookup" => quote! {
+            fn lookup(&mut self, _at: VnodeRef, _name: &str) -> Result<VnodeRef, Errno> {
+                #behavior
+            }
+        },
+        "stat" => quote! {
+            fn stat(&mut self, _at: VnodeRef, _stat: &mut Stat) -> Result<(), Errno> {
+                #behavior
+            }
+        },
+        "truncate" => quote! {
+            fn truncate(&mut self, _node: VnodeRef, _size: usize) -> Result<(), Errno> {
+                #behavior
+            }
+        },
+        "size" => quote! {
+            fn size(&mut self, _node: VnodeRef) -> Result<usize, Errno> {
+                #behavior
+            }
+        },
+        "read" => quote! {
+            fn read(&mut self, _node: VnodeRef, _pos: usize, _data: &mut [u8]) -> Result<usize, Errno> {
+                #behavior
+            }
+        },
+        "write" => quote! {
+            fn write(&mut self, _node: VnodeRef, _pos: usize, _data: &[u8]) -> Result<usize, Errno> {
+                #behavior
+            }
+        },
+        "open" => quote! {
+            fn open(&mut self, _node: VnodeRef, _flags: OpenFlags) -> Result<usize, Errno> {
+                #behavior
+            }
+        },
+        "close" => quote! {
+            fn close(&mut self, _node: VnodeRef) -> Result<(), Errno> {
+                #behavior
+            }
+        },
+        "ioctl" => quote! {
+            fn ioctl(&mut self, _node: VnodeRef, _cmd: IoctlCmd, _ptr: usize, _len: usize) -> Result<usize, Errno> {
+                #behavior
+            }
+        },
+        _ => panic!("TODO implement {:?}", name),
+    })
+}
+
+#[proc_macro_attribute]
+pub fn auto_inode(attr: TokenStream, input: TokenStream) -> TokenStream {
+    let mut impl_item = parse_macro_input!(input as ItemImpl);
+    let mut missing = HashSet::<String>::new();
+    let behavior = if attr.is_empty() {
+        "unimplemented".to_string()
+    } else {
+        parse_macro_input!(attr as Ident).to_string()
+    };
+    let behavior = match behavior.as_str() {
+        "unimplemented" => quote! { unimplemented!() },
+        "panic" => quote! { panic!() },
+        "error" => quote! { Err(libsys::error::Errno::NotImplemented) },
+        _ => panic!("Unknown #[auto_inode] behavior: {:?}", behavior)
+    };
+
+    missing.insert("create".to_string());
+    missing.insert("remove".to_string());
+    missing.insert("lookup".to_string());
+    missing.insert("open".to_string());
+    missing.insert("close".to_string());
+    missing.insert("truncate".to_string());
+    missing.insert("read".to_string());
+    missing.insert("write".to_string());
+    missing.insert("stat".to_string());
+    missing.insert("size".to_string());
+    missing.insert("ioctl".to_string());
+
+    for item in &impl_item.items {
+        match item {
+            ImplItem::Method(method) => {
+                let name = &method.sig.ident.to_string();
+                if missing.contains(name) {
+                    missing.remove(name);
+                }
+            }
+            _ => panic!("Unexpected impl item"),
+        }
+    }
+
+    for item in &missing {
+        impl_item
+            .items
+            .push(impl_inode_fn(item, behavior.clone()));
+    }
+
+    impl_item.to_token_stream().into()
+}

fs/vfs/Cargo.toml

@@ -7,3 +7,4 @@ edition = "2021"
 
 [dependencies]
 libsys = { path = "../../libsys" }
+fs-macros = { path = "../macros" }

fs/vfs/src/char.rs

@@ -25,19 +25,8 @@ pub struct CharDeviceWrapper {
     device: &'static dyn CharDevice,
 }
 
+#[auto_inode(error)]
 impl VnodeImpl for CharDeviceWrapper {
-    fn create(&mut self, _at: VnodeRef, _name: &str, _kind: VnodeKind) -> Result<VnodeRef, Errno> {
-        panic!();
-    }
-
-    fn remove(&mut self, _at: VnodeRef, _name: &str) -> Result<(), Errno> {
-        panic!();
-    }
-
-    fn lookup(&mut self, _at: VnodeRef, _name: &str) -> Result<VnodeRef, Errno> {
-        panic!();
-    }
-
     fn open(&mut self, _node: VnodeRef, _opts: OpenFlags) -> Result<usize, Errno> {
         Ok(0)
     }
@@ -54,18 +43,6 @@ impl VnodeImpl for CharDeviceWrapper {
         self.device.write(true, data)
     }
 
-    fn truncate(&mut self, _node: VnodeRef, _size: usize) -> Result<(), Errno> {
-        panic!();
-    }
-
-    fn size(&mut self, _node: VnodeRef) -> Result<usize, Errno> {
-        panic!();
-    }
-
-    fn stat(&mut self, _node: VnodeRef, _stat: &mut Stat) -> Result<(), Errno> {
-        todo!();
-    }
-
     fn ioctl(&mut self, _node: VnodeRef, cmd: IoctlCmd, ptr: usize, len: usize) -> Result<usize, Errno> {
         self.device.ioctl(cmd, ptr, len)
     }

fs/vfs/src/file.rs

@@ -3,8 +3,8 @@ use alloc::rc::Rc;
 use core::cell::RefCell;
 use core::cmp::min;
 use libsys::{
+    error::Errno,
     traits::{Read, Seek, SeekDir, Write},
-    error::Errno
 };
 
 struct NormalFile {
@@ -135,11 +135,13 @@ impl Drop for File {
 mod tests {
     use super::*;
     use crate::{Vnode, VnodeImpl, VnodeKind, VnodeRef};
+    use libsys::{stat::OpenFlags, ioctl::IoctlCmd, stat::Stat};
     use alloc::boxed::Box;
     use alloc::rc::Rc;
 
     struct DummyInode;
 
+    #[auto_inode]
     impl VnodeImpl for DummyInode {
         fn create(
             &mut self,
@@ -152,25 +154,17 @@ mod tests {
             Ok(node)
         }
 
-        fn remove(&mut self, _at: VnodeRef, _name: &str) -> Result<(), Errno> {
-            Err(Errno::NotImplemented)
-        }
-
-        fn lookup(&mut self, _at: VnodeRef, _name: &str) -> Result<VnodeRef, Errno> {
-            todo!()
-        }
-
-        fn open(&mut self, _node: VnodeRef) -> Result<usize, Errno> {
+        fn open(&mut self, _node: VnodeRef, _flags: OpenFlags) -> Result<usize, Errno> {
             Ok(0)
         }
 
         fn close(&mut self, _node: VnodeRef) -> Result<(), Errno> {
-            Err(Errno::NotImplemented)
+            Ok(())
         }
 
         fn read(&mut self, _node: VnodeRef, pos: usize, data: &mut [u8]) -> Result<usize, Errno> {
             #[cfg(test)]
-            println!("read {}", pos);
+            println!("read {} at {}", data.len(), pos);
             let len = 123;
             if pos >= len {
                 return Ok(0);
@@ -185,41 +179,24 @@ mod tests {
         fn write(&mut self, _node: VnodeRef, _pos: usize, _data: &[u8]) -> Result<usize, Errno> {
             Err(Errno::NotImplemented)
         }
-
-        fn truncate(&mut self, _node: VnodeRef, _size: usize) -> Result<(), Errno> {
-            Err(Errno::NotImplemented)
-        }
-
-        fn size(&mut self, _node: VnodeRef) -> Result<usize, Errno> {
-            Err(Errno::NotImplemented)
-        }
     }
 
     #[test]
     fn test_normal_read() {
         let node = Vnode::new("", VnodeKind::Regular, 0);
         node.set_data(Box::new(DummyInode {}));
-        let mut file = node.open().unwrap();
-
-        match &file.inner {
-            FileInner::Normal(inner) => {
-                assert!(Rc::ptr_eq(&inner.vnode, &node));
-                assert_eq!(inner.pos, 0);
-            }
-            _ => panic!("Invalid file.inner"),
-        }
-
+        let mut file = node.open(OpenFlags::O_RDONLY).unwrap();
         let mut buf = [0u8; 4096];
 
-        assert_eq!(file.read(&mut buf[0..32]).unwrap(), 32);
+        assert_eq!(file.borrow_mut().read(&mut buf[0..32]).unwrap(), 32);
         for i in 0..32 {
             assert_eq!((i & 0xFF) as u8, buf[i]);
         }
-        assert_eq!(file.read(&mut buf[0..64]).unwrap(), 64);
+        assert_eq!(file.borrow_mut().read(&mut buf[0..64]).unwrap(), 64);
         for i in 0..64 {
             assert_eq!(((i + 32) & 0xFF) as u8, buf[i]);
         }
-        assert_eq!(file.read(&mut buf[0..64]).unwrap(), 27);
+        assert_eq!(file.borrow_mut().read(&mut buf[0..64]).unwrap(), 27);
         for i in 0..27 {
             assert_eq!(((i + 96) & 0xFF) as u8, buf[i]);
         }

fs/vfs/src/ioctx.rs

@@ -1,7 +1,7 @@
 use crate::{FileMode, FileRef, OpenFlags, VnodeKind, VnodeRef};
 use libsys::{
     error::Errno,
-    path::{path_component_left, path_component_right}
+    path::{path_component_left, path_component_right},
 };
 
 /// I/O context structure
@@ -119,9 +119,11 @@ mod tests {
     use super::*;
     use crate::{Vnode, VnodeImpl, VnodeKind};
     use alloc::{boxed::Box, rc::Rc};
+    use libsys::{ioctl::IoctlCmd, stat::OpenFlags, stat::Stat};
 
     pub struct DummyInode;
 
+    #[auto_inode]
     impl VnodeImpl for DummyInode {
         fn create(
             &mut self,
@@ -134,37 +136,9 @@ mod tests {
             Ok(vnode)
         }
 
-        fn remove(&mut self, _at: VnodeRef, _name: &str) -> Result<(), Errno> {
-            todo!()
-        }
-
         fn lookup(&mut self, _at: VnodeRef, _name: &str) -> Result<VnodeRef, Errno> {
             Err(Errno::DoesNotExist)
         }
-
-        fn open(&mut self, _node: VnodeRef) -> Result<usize, Errno> {
-            todo!()
-        }
-
-        fn close(&mut self, _node: VnodeRef) -> Result<(), Errno> {
-            todo!()
-        }
-
-        fn read(&mut self, _node: VnodeRef, _pos: usize, _data: &mut [u8]) -> Result<usize, Errno> {
-            todo!()
-        }
-
-        fn write(&mut self, _node: VnodeRef, _pos: usize, _data: &[u8]) -> Result<usize, Errno> {
-            todo!()
-        }
-
-        fn truncate(&mut self, _node: VnodeRef, _size: usize) -> Result<(), Errno> {
-            todo!()
-        }
-
-        fn size(&mut self, _node: VnodeRef) -> Result<usize, Errno> {
-            todo!()
-        }
     }
 
     #[test]

fs/vfs/src/lib.rs

@@ -7,6 +7,9 @@
 #[macro_use]
 extern crate std;
 
+#[macro_use]
+extern crate fs_macros;
+
 extern crate alloc;
 
 pub use libsys::stat::{FileMode, OpenFlags, Stat};

fs/vfs/src/node.rs

@@ -405,8 +405,10 @@ impl fmt::Debug for Vnode {
 mod tests {
     use super::*;
 
+    use libsys::{stat::OpenFlags, ioctl::IoctlCmd, stat::Stat};
     pub struct DummyInode;
 
+    #[auto_inode]
     impl VnodeImpl for DummyInode {
         fn create(
             &mut self,
@@ -426,30 +428,6 @@ mod tests {
         fn lookup(&mut self, _at: VnodeRef, _name: &str) -> Result<VnodeRef, Errno> {
             Err(Errno::DoesNotExist)
         }
-
-        fn open(&mut self, _node: VnodeRef) -> Result<usize, Errno> {
-            Err(Errno::NotImplemented)
-        }
-
-        fn close(&mut self, _node: VnodeRef) -> Result<(), Errno> {
-            Err(Errno::NotImplemented)
-        }
-
-        fn read(&mut self, _node: VnodeRef, _pos: usize, _data: &mut [u8]) -> Result<usize, Errno> {
-            Err(Errno::NotImplemented)
-        }
-
-        fn write(&mut self, _node: VnodeRef, _pos: usize, _data: &[u8]) -> Result<usize, Errno> {
-            Err(Errno::NotImplemented)
-        }
-
-        fn truncate(&mut self, _node: VnodeRef, _size: usize) -> Result<(), Errno> {
-            Err(Errno::NotImplemented)
-        }
-
-        fn size(&mut self, _node: VnodeRef) -> Result<usize, Errno> {
-            Err(Errno::NotImplemented)
-        }
     }
 
     #[test]
@@ -469,10 +447,10 @@ mod tests {
 
         root.set_data(Box::new(DummyInode {}));
 
-        let node = root.mkdir("test", FileMode::default_dir()).unwrap();
+        let node = root.create("test", FileMode::default_dir(), VnodeKind::Directory).unwrap();
 
         assert_eq!(
-            root.mkdir("test", FileMode::default_dir()).unwrap_err(),
+            root.create("test", FileMode::default_dir(), VnodeKind::Directory).unwrap_err(),
             Errno::AlreadyExists
         );