| use crate::{Error, Result}; |
| use proc_macro2::{Ident, Span, TokenStream, TokenTree}; |
| |
| macro_rules! decl_settings { |
| ($($val:expr => $variant:ident),+ $(,)*) => { |
| #[derive(PartialEq)] |
| pub(crate) enum Setting { |
| $($variant),* |
| } |
| |
| fn ident_to_setting(ident: Ident) -> Result<Setting> { |
| match &*ident.to_string() { |
| $($val => Ok(Setting::$variant),)* |
| _ => { |
| let possible_vals = [$($val),*] |
| .iter() |
| .map(|v| format!("`{}`", v)) |
| .collect::<Vec<_>>() |
| .join(", "); |
| |
| Err(Error::new( |
| ident.span(), |
| format!("unknown setting `{}`, expected one of {}", ident, possible_vals))) |
| } |
| } |
| } |
| }; |
| } |
| |
| decl_settings! { |
| "assert_unwind_safe" => AssertUnwindSafe, |
| "allow_not_macro" => AllowNotMacro, |
| "proc_macro_hack" => ProcMacroHack, |
| } |
| |
| pub(crate) fn parse_settings(input: TokenStream) -> Result<Settings> { |
| let mut input = input.into_iter(); |
| let mut res = Settings(Vec::new()); |
| loop { |
| match input.next() { |
| Some(TokenTree::Ident(ident)) => { |
| res.0.push(ident_to_setting(ident)?); |
| } |
| None => return Ok(res), |
| other => { |
| let span = other.map_or(Span::call_site(), |tt| tt.span()); |
| return Err(Error::new(span, "expected identifier".to_string())); |
| } |
| } |
| |
| match input.next() { |
| Some(TokenTree::Punct(ref punct)) if punct.as_char() == ',' => {} |
| None => return Ok(res), |
| other => { |
| let span = other.map_or(Span::call_site(), |tt| tt.span()); |
| return Err(Error::new(span, "expected `,`".to_string())); |
| } |
| } |
| } |
| } |
| |
| pub(crate) struct Settings(Vec<Setting>); |
| |
| impl Settings { |
| pub(crate) fn is_set(&self, setting: Setting) -> bool { |
| self.0.iter().any(|s| *s == setting) |
| } |
| |
| pub(crate) fn set(&mut self, setting: Setting) { |
| self.0.push(setting) |
| } |
| } |