66 lines
1.5 KiB
Rust
66 lines
1.5 KiB
Rust
//! A derive macro for generation of simple `Externals`.
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//!
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//! ```nocompile
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//! #// no compile because we can't depend on wasmi here, or otherwise it will be a circular dependency.
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//! extern crate wasmi;
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//! extern crate wasmi_derive;
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//!
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//! use std::fmt;
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//! use wasmi::HostError;
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//! use wasmi_derive::derive_externals;
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//!
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//! #[derive(Debug)]
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//! struct NoInfoError;
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//! impl HostError for NoInfoError {}
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//! impl fmt::Display for NoInfoError {
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//! fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
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//! write!(f, "NoInfoError")
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//! }
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//! }
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//!
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//! struct NonStaticExternals<'a> {
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//! state: &'a mut usize,
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//! }
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//!
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//! #[derive_externals]
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//! impl<'a> NonStaticExternals<'a> {
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//! pub fn add(&self, a: u32, b: u32) -> u32 {
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//! a + b
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//! }
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//!
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//! pub fn increment(&mut self) {
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//! *self.state += 1;
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//! }
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//!
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//! pub fn traps(&self) -> Result<(), NoInfoError> {
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//! Err(NoInfoError)
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//! }
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//! }
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//! ```
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//!
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// We reached the `recursion_limit` in quote macro.
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#![recursion_limit = "128"]
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extern crate proc_macro;
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#[macro_use]
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mod error;
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mod codegen;
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mod parser;
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use proc_macro::TokenStream;
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#[proc_macro_attribute]
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pub fn derive_externals(_attr: TokenStream, input: TokenStream) -> TokenStream {
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let mut input: proc_macro2::TokenStream = input.into();
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match parser::parse(input.clone()) {
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Ok(ext_def) => {
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codegen::codegen(&ext_def, &mut input);
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input.into()
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}
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Err(err) => (quote::quote! { #err }).into(),
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}
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}
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