Move to generating code using build.rs

Cargo.toml

@@ -12,7 +12,6 @@ members = ["protogen"]
 byteorder = "1.5.0"
 bytes = "1.10.0"
 nix = "0.29.0"
-protogen = { version = "0.1.0", path = "protogen" }
 sendfd = { version = "0.4", features = [ "tokio" ] }
 serde = "1.0.218"
 serde_derive = "1.0.218"
@@ -20,3 +19,6 @@ tokio = { version = "1.43.0", features = [ "fs", "net", "rt", "rt-multi-thread",
 toml = "0.8.20"
 tracing = "0.1.41"
 tracing-subscriber = "0.3.19"
+
+[build-dependencies]
+protogen = { version = "0.1.0", path = "protogen" }

build.rs

@@ -0,0 +1,19 @@
+use std::{env, path::Path};
+
+fn main() {
+    let out_dir = env::var_os("OUT_DIR").unwrap();
+    let out_file = Path::new(&out_dir).join("proto_generated.rs");
+
+    std::fs::write(&out_file, protogen::generate_from_dir("proto"))
+        .expect("unable to write to file");
+
+    // If rustfmt is present, run rustfmt so that the generated file is somewhat human-readable
+    std::process::Command::new("rustfmt")
+        .arg(out_file.to_str().expect("utf8 error"))
+        .output()
+        .ok();
+
+    println!("cargo::rerun-if-changed=build.rs");
+    println!("cargo::rerun-if-changed=proto");
+    println!("cargo::rerun-if-changed=protogen");
+}

protogen/Cargo.toml

@@ -3,9 +3,6 @@ name = "protogen"
 version = "0.1.0"
 edition = "2024"
 
-[lib]
-proc-macro = true
-
 [dependencies]
 proc-macro2 = "1.0.93"
 quick-xml = "0.37.2"

protogen/src/lib.rs

@@ -1,17 +1,42 @@
-use std::path::PathBuf;
+use std::path::Path;
 
 use quick_xml::events::Event;
 use quote::{format_ident, quote};
-use syn::{Ident, LitStr, parse_macro_input};
+use syn::Ident;
 use types::{WlArgType, WlInterface, WlMsg, WlMsgType};
 
 mod types;
 
-#[proc_macro]
-pub fn wayland_proto_gen(item: proc_macro::TokenStream) -> proc_macro::TokenStream {
-    let input: LitStr = parse_macro_input!(item);
-    let p = PathBuf::from(input.value());
-    let file_name = p.file_stem().expect("No file name provided");
+pub fn generate_from_dir(p: impl AsRef<Path>) -> String {
+    let (gen_code, (add_parsers_fn, add_object_types_fn)): (Vec<_>, (Vec<_>, Vec<_>)) =
+        std::fs::read_dir(p)
+            .expect("cannot open directory")
+            .filter_map(|f| f.ok())
+            .filter(|f| {
+                f.file_name()
+                    .to_str()
+                    .expect("utf8 encoding error")
+                    .ends_with(".xml")
+            })
+            .map(|f| generate_from_xml_file(f.path()))
+            .unzip();
+
+    quote! {
+        #( #gen_code )*
+
+        pub fn wl_init_parsers() {
+            #( #add_parsers_fn(); )*
+        }
+
+        pub fn wl_init_known_types() {
+            #( #add_object_types_fn(); )*
+        }
+    }
+    .to_string()
+}
+
+fn generate_from_xml_file(p: impl AsRef<Path>) -> (proc_macro2::TokenStream, (Ident, Ident)) {
+    let file_name = p.as_ref().file_stem().expect("No file name provided");
     let xml_str = std::fs::read_to_string(&p).expect("Unable to read from file");
     let mut reader = quick_xml::Reader::from_str(&xml_str);
     reader.config_mut().trim_text(true);
@@ -63,13 +88,15 @@ pub fn wayland_proto_gen(item: proc_macro::TokenStream) -> proc_macro::TokenStre
         }
     }
 
+    let file_name_snake = file_name.to_str().unwrap().replace("-", "_");
+
     // A function to add all event/request parsers to WL_EVENT_PARSERS and WL_REQUEST_PARSERS
-    let add_parsers_fn = format_ident!("wl_init_parsers_{}", file_name.to_str().unwrap());
+    let add_parsers_fn = format_ident!("wl_init_parsers_{}", file_name_snake);
 
     // A function to add all known interfaces to the WL_KNOWN_OBJECT_TYPES map from name -> Rust type
-    let add_object_types_fn = format_ident!("wl_init_known_types_{}", file_name.to_str().unwrap());
+    let add_object_types_fn = format_ident!("wl_init_known_types_{}", file_name_snake);
 
-    quote! {
+    let ret_code = quote! {
         #( #code )*
 
         fn #add_parsers_fn() {
@@ -80,8 +107,9 @@ pub fn wayland_proto_gen(item: proc_macro::TokenStream) -> proc_macro::TokenStre
         fn #add_object_types_fn() {
             #( WL_KNOWN_OBJECT_TYPES.write().unwrap().insert(#known_interface_names, #known_interface_consts); )*
         }
-    }
-    .into()
+    };
+
+    (ret_code, (add_parsers_fn, add_object_types_fn))
 }
 
 fn handle_interface(

protogen/src/types.rs

@@ -113,6 +113,7 @@ impl WlMsg {
             .collect();
 
         quote! {
+            #[allow(unused)]
             pub struct #struct_name<'a> {
                 _phantom: std::marker::PhantomData<&'a ()>,
                 #( pub #field_names: #field_types, )*
@@ -145,6 +146,7 @@ impl WlMsg {
                     WlMsgType::#msg_type
                 }
 
+                #[allow(unused)]
                 fn try_from_msg_impl(msg: &crate::codec::WlRawMsg) -> WaylandProtocolParsingOutcome<#struct_name> {
                     let payload = msg.payload();
                     let mut pos = 0usize;

src/proto.rs

@@ -7,7 +7,6 @@ use std::{
 };
 
 use byteorder::ByteOrder;
-use protogen::wayland_proto_gen;
 
 use crate::{
     codec::WlRawMsg,
@@ -218,13 +217,5 @@ pub fn lookup_known_object_type(name: &str) -> Option<WlObjectType> {
 /// The default object ID of wl_display
 pub const WL_DISPLAY_OBJECT_ID: u32 = 1;
 
-wayland_proto_gen!("proto/wayland.xml");
-
-/// Install all available Wayland protocol parsers for use by [decode_event] and [decode_request].
-pub fn wl_init_parsers() {
-    wl_init_parsers_wayland();
-}
-
-pub fn wl_init_known_types() {
-    wl_init_known_types_wayland();
-}
+// Include code generated by build.rs
+include!(concat!(env!("OUT_DIR"), "/proto_generated.rs"));