55 lines
1.5 KiB
Rust
55 lines
1.5 KiB
Rust
use proc_macro2::{Literal, TokenStream, TokenTree};
|
|
/// Given the input tokens to a macro invocation, return the path to the
|
|
/// witx file to process.
|
|
pub(crate) fn witx_path_from_args(args: TokenStream) -> (String, String) {
|
|
let mut strings = Vec::new();
|
|
|
|
for arg in args {
|
|
if let TokenTree::Literal(literal) = arg {
|
|
let parsed = parse_string_literal(literal);
|
|
|
|
strings.push(parsed);
|
|
} else {
|
|
panic!("arguments must be string literals");
|
|
}
|
|
}
|
|
|
|
if strings.len() != 2 {
|
|
panic!("expected two string literals");
|
|
}
|
|
|
|
let phase = &strings[0];
|
|
let id = &strings[1];
|
|
let path = witx_path(phase, id);
|
|
|
|
(path, phase.clone())
|
|
}
|
|
|
|
fn witx_path(phase: &str, id: &str) -> String {
|
|
let root = std::env::var("CARGO_MANIFEST_DIR").unwrap_or(".".into());
|
|
format!("{}/WASI/phases/{}/witx/{}.witx", root, phase, id)
|
|
}
|
|
|
|
// Convert a `Literal` holding a string literal into the `String`.
|
|
//
|
|
// FIXME: It feels like there should be an easier way to do this.
|
|
fn parse_string_literal(literal: Literal) -> String {
|
|
let s = literal.to_string();
|
|
assert!(
|
|
s.starts_with('"') && s.ends_with('"'),
|
|
"string literal must be enclosed in double-quotes"
|
|
);
|
|
|
|
let trimmed = s[1..s.len() - 1].to_owned();
|
|
assert!(
|
|
!trimmed.contains('"'),
|
|
"string literal must not contain embedded quotes for now"
|
|
);
|
|
assert!(
|
|
!trimmed.contains('\\'),
|
|
"string literal must not contain embedded backslashes for now"
|
|
);
|
|
|
|
trimmed
|
|
}
|