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Diffstat (limited to '')
-rw-r--r-- | vendor/serde_derive/src/internals/ctxt.rs | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/vendor/serde_derive/src/internals/ctxt.rs b/vendor/serde_derive/src/internals/ctxt.rs new file mode 100644 index 000000000..d692c2a44 --- /dev/null +++ b/vendor/serde_derive/src/internals/ctxt.rs @@ -0,0 +1,62 @@ +use quote::ToTokens; +use std::cell::RefCell; +use std::fmt::Display; +use std::thread; +use syn; + +/// A type to collect errors together and format them. +/// +/// Dropping this object will cause a panic. It must be consumed using `check`. +/// +/// References can be shared since this type uses run-time exclusive mut checking. +#[derive(Default)] +pub struct Ctxt { + // The contents will be set to `None` during checking. This is so that checking can be + // enforced. + errors: RefCell<Option<Vec<syn::Error>>>, +} + +impl Ctxt { + /// Create a new context object. + /// + /// This object contains no errors, but will still trigger a panic if it is not `check`ed. + pub fn new() -> Self { + Ctxt { + errors: RefCell::new(Some(Vec::new())), + } + } + + /// Add an error to the context object with a tokenenizable object. + /// + /// The object is used for spanning in error messages. + pub fn error_spanned_by<A: ToTokens, T: Display>(&self, obj: A, msg: T) { + self.errors + .borrow_mut() + .as_mut() + .unwrap() + // Curb monomorphization from generating too many identical methods. + .push(syn::Error::new_spanned(obj.into_token_stream(), msg)); + } + + /// Add one of Syn's parse errors. + pub fn syn_error(&self, err: syn::Error) { + self.errors.borrow_mut().as_mut().unwrap().push(err); + } + + /// Consume this object, producing a formatted error string if there are errors. + pub fn check(self) -> Result<(), Vec<syn::Error>> { + let errors = self.errors.borrow_mut().take().unwrap(); + match errors.len() { + 0 => Ok(()), + _ => Err(errors), + } + } +} + +impl Drop for Ctxt { + fn drop(&mut self) { + if !thread::panicking() && self.errors.borrow().is_some() { + panic!("forgot to check for errors"); + } + } +} |