40 lines
1.7 KiB
Rust
40 lines
1.7 KiB
Rust
#[macro_use]
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extern crate syn;
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#[macro_use]
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extern crate quote;
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use proc_macro::TokenStream;
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use quote::ToTokens;
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use syn::{ReturnType, ItemFn};
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fn check_lua_function(input: &mut ItemFn) {
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assert!(input.sig.asyncness.is_none(), "Cannot be async");
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assert!(input.sig.constness.is_none(), "Cannot be const");
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assert!(input.sig.inputs.len() == 1, "There can only be one argument, and it should be a pointer to the Lua state (gmod::lua::State)");
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assert!(matches!(&input.sig.output, ReturnType::Type(_, r#type) if r#type.to_token_stream().to_string() == "i32"), "The output must be an i32, representing the number of return values of the function");
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assert!(input.sig.abi.is_none() || input.sig.abi.as_ref().and_then(|abi| abi.name.as_ref()).map(|abi| abi.value() == "C-unwind").unwrap_or(true), "Do not specify an ABI");
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input.sig.abi = Some(syn::parse_quote!(extern "C-unwind"));
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}
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#[proc_macro_attribute]
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pub fn gmod13_open(_attr: TokenStream, tokens: TokenStream) -> TokenStream {
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let mut input = parse_macro_input!(tokens as ItemFn);
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check_lua_function(&mut input);
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input.block.stmts.insert(0, syn::parse2(quote!(#[allow(unused_unsafe)] unsafe { ::gmod::lua::load() })).unwrap());
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TokenStream::from(quote!(#[no_mangle] #input))
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}
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#[proc_macro_attribute]
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pub fn gmod13_close(_attr: TokenStream, tokens: TokenStream) -> TokenStream {
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let mut input = parse_macro_input!(tokens as ItemFn);
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check_lua_function(&mut input);
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TokenStream::from(quote!(#[no_mangle] #input))
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}
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#[proc_macro_attribute]
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pub fn lua_function(_attr: TokenStream, tokens: TokenStream) -> TokenStream {
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let mut input = parse_macro_input!(tokens as ItemFn);
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check_lua_function(&mut input);
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TokenStream::from(quote!(#input))
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} |