Add placeholder for cbindgen proc_macro_attribute

wasi-common-cbindgen/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "wasi-common-cbindgen"
+version = "0.1.0"
+authors = ["Jakub Konka <kubkon@jakubkonka.com>"]
+edition = "2018"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = { version = "0.15.34", features = ["full"] }
+quote = "0.6.12"
+proc-macro2 = "0.4.30"

wasi-common-cbindgen/src/lib.rs

@@ -0,0 +1,18 @@
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{FnArg, ArgCaptured, Pat, PatIdent};
+use std::collections::HashMap;
+
+#[proc_macro_attribute]
+pub fn wasi_common_cbindgen(attr: TokenStream, function: TokenStream) -> TokenStream {
+    assert!(attr.is_empty());
+
+    let function = syn::parse_macro_input!(function as syn::ItemFn);
+    let result = quote! {
+        #function
+    };
+
+    result.into()
+}