| // tidy-alphabetical-start |
| #![allow(internal_features)] |
| #![allow(rustc::default_hash_types)] |
| #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")] |
| #![doc(rust_logo)] |
| #![feature(proc_macro_diagnostic)] |
| #![feature(proc_macro_span)] |
| #![feature(rustdoc_internals)] |
| #![warn(unreachable_pub)] |
| // tidy-alphabetical-end |
| |
| use proc_macro::TokenStream; |
| |
| mod fluent; |
| |
| /// Implements the `fluent_messages` macro, which performs compile-time validation of the |
| /// compiler's Fluent resources (i.e. that the resources parse and don't multiply define the same |
| /// messages) and generates constants that make using those messages in diagnostics more ergonomic. |
| /// |
| /// For example, given the following invocation of the macro.. |
| /// |
| /// ```ignore (rust) |
| /// fluent_messages! { "./typeck.ftl" } |
| /// ``` |
| /// ..where `typeck.ftl` has the following contents.. |
| /// |
| /// ```fluent |
| /// typeck_field_multiply_specified_in_initializer = |
| /// field `{$ident}` specified more than once |
| /// .label = used more than once |
| /// .label_previous_use = first use of `{$ident}` |
| /// ``` |
| /// ...then the macro parse the Fluent resource, emitting a diagnostic if it fails to do so, and |
| /// will generate the following code: |
| /// |
| /// ```ignore (rust) |
| /// pub static DEFAULT_LOCALE_RESOURCE: &'static [&'static str] = include_str!("./typeck.ftl"); |
| /// |
| /// mod fluent_generated { |
| /// mod typeck { |
| /// pub const field_multiply_specified_in_initializer: DiagMessage = |
| /// DiagMessage::fluent("typeck_field_multiply_specified_in_initializer"); |
| /// pub const field_multiply_specified_in_initializer_label_previous_use: DiagMessage = |
| /// DiagMessage::fluent_attr( |
| /// "typeck_field_multiply_specified_in_initializer", |
| /// "previous_use_label" |
| /// ); |
| /// } |
| /// } |
| /// ``` |
| /// When emitting a diagnostic, the generated constants can be used as follows: |
| /// |
| /// ```ignore (rust) |
| /// let mut err = sess.struct_span_err( |
| /// span, |
| /// fluent::typeck::field_multiply_specified_in_initializer |
| /// ); |
| /// err.span_default_label(span); |
| /// err.span_label( |
| /// previous_use_span, |
| /// fluent::typeck::field_multiply_specified_in_initializer_label_previous_use |
| /// ); |
| /// err.emit(); |
| /// ``` |
| /// |
| /// Note: any crate using this macro must also have a dependency on |
| /// `rustc_errors`, because the generated code refers to things from that |
| /// crate. |
| #[proc_macro] |
| pub fn fluent_messages(input: TokenStream) -> TokenStream { |
| fluent::fluent_messages(input) |
| } |