| // Copyright (c) 2017 Baidu, Inc. All Rights Reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions |
| // are met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above copyright |
| // notice, this list of conditions and the following disclaimer in |
| // the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Baidu, Inc., nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| //! Support for `#[derive(Rand)]` |
| //! |
| //! **Note** |
| //! |
| //! TcsPolicy must be Bound. |
| //! |
| //! # Examples |
| //! |
| //! ``` |
| //! extern crate sgx_rand; |
| //! #[macro_use] |
| //! extern crate sgx_rand_derive; |
| //! |
| //! #[derive(Rand, Debug)] |
| //! struct MyStruct { |
| //! a: i32, |
| //! b: u32, |
| //! } |
| //! |
| //! fn main() { |
| //! println!("{:?}", sgx_rand::random::<MyStruct>()); |
| //! } |
| //! ``` |
| #![crate_name = "sgx_rand_derive"] |
| #![crate_type = "rlib"] |
| |
| extern crate proc_macro; |
| #[macro_use] |
| extern crate quote; |
| extern crate syn; |
| |
| use proc_macro::TokenStream; |
| |
| #[proc_macro_derive(Rand)] |
| pub fn rand_derive(input: TokenStream) -> TokenStream { |
| let s = input.to_string(); |
| let ast = syn::parse_derive_input(&s).unwrap(); |
| let gen = impl_rand_derive(&ast); |
| gen.parse().unwrap() |
| } |
| |
| fn impl_rand_derive(ast: &syn::MacroInput) -> quote::Tokens { |
| let name = &ast.ident; |
| let (impl_generics, ty_generics, where_clause) = ast.generics.split_for_impl(); |
| |
| let rand = match ast.body { |
| syn::Body::Struct(syn::VariantData::Struct(ref body)) => { |
| let fields = body |
| .iter() |
| .filter_map(|field| field.ident.as_ref()) |
| .map(|ident| quote! { #ident: __rng.gen() }) |
| .collect::<Vec<_>>(); |
| |
| quote! { #name { #(#fields,)* } } |
| }, |
| syn::Body::Struct(syn::VariantData::Tuple(ref body)) => { |
| let fields = (0..body.len()) |
| .map(|_| quote! { __rng.gen() }) |
| .collect::<Vec<_>>(); |
| |
| quote! { #name (#(#fields),*) } |
| }, |
| syn::Body::Struct(syn::VariantData::Unit) => { |
| quote! { #name } |
| }, |
| syn::Body::Enum(ref body) => { |
| if body.is_empty() { |
| panic!("`Rand` cannot be derived for enums with no variants"); |
| } |
| |
| let len = body.len(); |
| let mut variants = body |
| .iter() |
| .enumerate() |
| .map(|(index, variant)| { |
| let ident = &variant.ident; |
| let arm = match variant.data { |
| syn::VariantData::Struct(ref body) => { |
| let fields = body |
| .iter() |
| .filter_map(|field| field.ident.as_ref()) |
| .map(|ident| quote! { #ident: __rng.gen() }) |
| .collect::<Vec<_>>(); |
| quote! { #name::#ident { #(#fields,)* } } |
| }, |
| syn::VariantData::Tuple(ref body) => { |
| let fields = (0..body.len()) |
| .map(|_| quote! { __rng.gen() }) |
| .collect::<Vec<_>>(); |
| |
| quote! { #name::#ident (#(#fields),*) } |
| }, |
| syn::VariantData::Unit => quote! { #name::#ident } |
| }; |
| |
| quote! { #index => #arm } |
| }) |
| .collect::<Vec<_>>(); |
| variants.push(quote! { _ => unreachable!() }); |
| quote! { match __rng.gen_range(0, #len) { #(#variants,)* } } |
| } |
| }; |
| |
| quote! { |
| impl #impl_generics ::sgx_rand::Rand for #name #ty_generics #where_clause { |
| #[inline] |
| fn rand<__R: ::sgx_rand::Rng>(__rng: &mut __R) -> Self { |
| #rand |
| } |
| } |
| } |
| } |