| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| extern crate proc_macro; |
| use proc_macro::TokenStream; |
| use quote::quote; |
| use syn::parse_macro_input; |
| |
| #[proc_macro_attribute] |
| pub fn handle_ecall(_args: TokenStream, input: TokenStream) -> TokenStream { |
| let f = parse_macro_input!(input as syn::ItemFn); |
| let ident = &f.ident; |
| |
| let input_types: Vec<_> = f |
| .decl |
| .inputs |
| .iter() |
| .map(|arg| match arg { |
| &syn::FnArg::Captured(ref val) => &val.ty, |
| _ => unreachable!(), |
| }) |
| .collect(); |
| |
| let args_type = match input_types.first().unwrap() { |
| &syn::Type::Reference(ref r) => &r.elem, |
| _ => unreachable!(), |
| }; |
| |
| let ret_type = match &f.decl.output { |
| syn::ReturnType::Default => unreachable!(), |
| syn::ReturnType::Type(_, ty) => ty, |
| }; |
| |
| let generic_type = match **ret_type { |
| syn::Type::Path(ref path) => { |
| let type_params = &path.path.segments.iter().next().unwrap().arguments; |
| let generic_arg = match type_params { |
| syn::PathArguments::AngleBracketed(params) => params.args.iter().next().unwrap(), |
| _ => { |
| panic!("IPC Macro Attribute: unexpected return type, no AngleBracketed found.") |
| } |
| }; |
| |
| match generic_arg { |
| syn::GenericArgument::Type(ty) => ty.clone(), |
| _ => panic!("IPC Macro Attribute: unexpected return type, no generic found."), |
| } |
| } |
| _ => panic!("IPC Macro Attribute: unexpected return type."), |
| }; |
| |
| quote!( |
| impl HandleRequest<#generic_type> for #args_type { |
| fn handle(&self) -> #ret_type { |
| #ident(self) |
| } |
| } |
| |
| #f |
| ) |
| .into() |
| } |