Add the opensmtpd_derive crate

Cargo.toml

@@ -1,24 +1,5 @@
-[package]
-name = "opensmtpd"
-version = "0.3.0"
-authors = ["Rodolphe Bréard <rodolphe@what.tf>"]
-edition = "2018"
-description = "Interface for OpenSMTPD filters"
-keywords = ["opensmtpd", "filter", "mail"]
-documentation = "https://docs.rs/opensmtpd/"
-repository = "https://github.com/breard-r/rust-opensmtpd"
-readme = "README.md"
-license = "MIT OR Apache-2.0"
-include = ["src/**/*", "Cargo.toml", "LICENSE-*.txt"]
-
-[dependencies]
-log = "0.4"
-nom = "6.0"
-pretty-hex = "0.2"
-
-[dev-dependencies]
-simplelog = "0.9"
-
-[[example]]
-name = "counter"
-path = "examples/counter.rs"
+[workspace]
+members = [
+    "opensmtpd",
+    "opensmtpd-derive"
+]

opensmtpd-derive/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "opensmtpd_derive"
+version = "0.3.0"
+authors = ["Rodolphe Bréard <rodolphe@what.tf>"]
+edition = "2018"
+description = "Interface for OpenSMTPD filters"
+keywords = ["opensmtpd", "filter", "mail"]
+documentation = "https://docs.rs/opensmtpd-derive/"
+repository = "https://github.com/breard-r/rust-opensmtpd"
+readme = "README.md"
+license = "MIT OR Apache-2.0"
+include = ["src/**/*", "Cargo.toml", "../LICENSE-*.txt"]
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0"
+quote = "1.0"
+syn = { version = "1.0", features = ["full", "extra-traits"] }

opensmtpd-derive/src/lib.rs

@@ -0,0 +1,18 @@
+use proc_macro::TokenStream;
+use proc_macro2::Span;
+use quote::quote;
+use syn::{parse_macro_input, Ident, ItemFn};
+
+#[proc_macro_attribute]
+pub fn register(_attr: TokenStream, input: TokenStream) -> TokenStream {
+    let item = parse_macro_input!(input as ItemFn);
+    let fn_name = item.sig.ident.to_string().replacen("on_", "has_", 1);
+    let fn_name = Ident::new(&fn_name, Span::call_site());
+    let output = quote! {
+        fn #fn_name(&self) -> bool {
+            true
+        }
+        #item
+    };
+    output.into()
+}

opensmtpd/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "opensmtpd"
+version = "0.3.0"
+authors = ["Rodolphe Bréard <rodolphe@what.tf>"]
+edition = "2018"
+description = "Interface for OpenSMTPD filters"
+keywords = ["opensmtpd", "filter", "mail"]
+documentation = "https://docs.rs/opensmtpd/"
+repository = "https://github.com/breard-r/rust-opensmtpd"
+readme = "README.md"
+license = "MIT OR Apache-2.0"
+include = ["src/**/*", "Cargo.toml", "../LICENSE-*.txt"]
+
+[dependencies]
+log = "0.4"
+nom = "6.0"
+opensmtpd_derive = { path = "../opensmtpd-derive" }
+pretty-hex = "0.2"
+
+[dev-dependencies]
+simplelog = "0.9"
+
+[[example]]
+name = "counter"
+path = "examples/counter.rs"

opensmtpd/examples/counter.rs

@@ -1,5 +1,6 @@
 use log;
-use opensmtpd::{register, run_filter, Address, Filter, ReportEntry};
+use opensmtpd::{run_filter, Address, Filter, ReportEntry};
+use opensmtpd_derive::register;
 use simplelog::{Config, LevelFilter, WriteLogger};
 use std::fs::File;
 
@@ -12,7 +13,7 @@ struct MyCounter {
 }
 
 impl Filter for MyCounter {
-    register!(has_report_link_connect);
+    #[register]
     fn on_report_link_connect(
         &mut self,
         _entry: &ReportEntry,
@@ -30,7 +31,7 @@ impl Filter for MyCounter {
         );
     }
 
-    register!(has_report_link_disconnect);
+    #[register]
     fn on_report_link_disconnect(&mut self, _entry: &ReportEntry) {
         self.nb_connected -= 1;
         log::info!(

opensmtpd/src/lib.rs

@@ -22,14 +22,15 @@
 //! disconnects.
 //!
 //! ```
-//! use opensmtpd::{register, run_filter, Filter, ReportEntry};
+//! use opensmtpd::{run_filter, Filter, ReportEntry};
+//! use opensmtpd_derive::register;
 //!
 //! struct MyCounter {
 //!     nb: u64,
 //! }
 //!
 //! impl Filter for MyCounter {
-//!     register!(has_report_link_disconnect);
+//!     #[register]
 //!     fn on_report_link_disconnect(&mut self, _entry: &ReportEntry) {
 //!         self.nb + 1;
 //!     }
@@ -72,15 +73,6 @@ use std::thread;
 
 const BUFFER_SIZE: usize = 4096;
 
-#[macro_export]
-macro_rules! register {
-    ($name: ident) => {
-        fn $name(&self) -> bool {
-            return true;
-        }
-    };
-}
-
 macro_rules! recv {
     ($rx: ident) => {
         match $rx.recv() {
@@ -127,7 +119,12 @@ macro_rules! handshake_register {
     ($obj: ident, $func: ident, $subsystem: expr, $type: expr, $name: expr) => {
         if $obj.$func() {
             println!("register|{}|{}|{}", $type, $subsystem.to_string(), $name);
-            log::trace!("{} {} for {} registered", $type, $name, $subsystem.to_string());
+            log::trace!(
+                "{} {} for {} registered",
+                $type,
+                $name,
+                $subsystem.to_string()
+            );
         }
     };
 }