change proc macro argument parsing to use syn

crates/generate/Cargo.toml

@@ -14,3 +14,4 @@ quote = "1.0"
 proc-macro2 = "1.0"
 heck = "0.3"
 anyhow = "1"
+syn = { version = "1.0", features = ["full"] }

crates/generate/src/config.rs

@@ -1,7 +1,37 @@
-use anyhow::{bail, Result};
-use proc_macro2::{Literal, TokenStream, TokenTree};
+use std::path::PathBuf;
 
-pub fn witx_paths(args: TokenStream) -> Result<Vec<String>> {
+use syn::{
+    bracketed,
+    parse::{Parse, ParseStream},
+    punctuated::Punctuated,
+    token, LitStr, Result, Token,
+};
+
+pub struct Config {
+    _bracket_token: token::Bracket,
+    path_lits: Punctuated<LitStr, Token![,]>,
+}
+
+impl Config {
+    pub fn witx_paths(&self) -> Vec<PathBuf> {
+        self.path_lits
+            .iter()
+            .map(|lit| PathBuf::from(lit.value()))
+            .collect()
+    }
+}
+
+impl Parse for Config {
+    fn parse(input: ParseStream) -> Result<Self> {
+        let content;
+        Ok(Config {
+            _bracket_token: bracketed!(content in input),
+            path_lits: content.parse_terminated(Parse::parse)?,
+        })
+    }
+}
+
+/*
     let arg_strings = args
         .into_iter()
         .map(|arg| match arg {
@@ -31,3 +61,4 @@ fn string_literal(literal: Literal) -> Result<String> {
     }
     Ok(trimmed)
 }
+*/

crates/generate/src/lib.rs

@@ -1,15 +1,16 @@
 extern crate proc_macro;
 
+mod config;
 mod funcs;
 mod module_trait;
 mod names;
-mod parse;
 mod types;
 
 use proc_macro::TokenStream;
-use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
+use syn::parse_macro_input;
 
+use config::Config;
 use funcs::define_func;
 use module_trait::define_module_trait;
 use names::Names;
@@ -17,12 +18,11 @@ use types::define_datatype;
 
 #[proc_macro]
 pub fn from_witx(args: TokenStream) -> TokenStream {
-    let args = TokenStream2::from(args);
-    let witx_paths = parse::witx_paths(args).expect("parsing macro arguments");
+    let config = parse_macro_input!(args as Config);
 
     let names = Names::new(); // TODO parse the names from the invocation of the macro, or from a file?
 
-    let doc = witx::load(&witx_paths).expect("loading witx");
+    let doc = witx::load(&config.witx_paths()).expect("loading witx");
 
     let types = doc.typenames().map(|t| define_datatype(&names, &t));
 

src/lib.rs

@@ -1,6 +1,6 @@
 pub mod test {
     // FIXME: parameterize macro on what ctx type is used here
-    generate::from_witx!("test.witx");
+    generate::from_witx!(["test.witx"]);
 
     pub struct WasiCtx {
         guest_errors: Vec<::memory::GuestError>,