diff options
Diffstat (limited to 'compiler/rustc_fluent_macro/src')
| -rw-r--r-- | compiler/rustc_fluent_macro/src/fluent.rs | 336 | ||||
| -rw-r--r-- | compiler/rustc_fluent_macro/src/lib.rs | 64 |
2 files changed, 400 insertions, 0 deletions
diff --git a/compiler/rustc_fluent_macro/src/fluent.rs b/compiler/rustc_fluent_macro/src/fluent.rs new file mode 100644 index 000000000..9dffc9a76 --- /dev/null +++ b/compiler/rustc_fluent_macro/src/fluent.rs @@ -0,0 +1,336 @@ +use annotate_snippets::{ + display_list::DisplayList, + snippet::{Annotation, AnnotationType, Slice, Snippet, SourceAnnotation}, +}; +use fluent_bundle::{FluentBundle, FluentError, FluentResource}; +use fluent_syntax::{ + ast::{ + Attribute, Entry, Expression, Identifier, InlineExpression, Message, Pattern, + PatternElement, + }, + parser::ParserError, +}; +use proc_macro::{Diagnostic, Level, Span}; +use proc_macro2::TokenStream; +use quote::quote; +use std::{ + collections::{HashMap, HashSet}, + fs::read_to_string, + path::{Path, PathBuf}, +}; +use syn::{parse_macro_input, Ident, LitStr}; +use unic_langid::langid; + +/// Helper function for returning an absolute path for macro-invocation relative file paths. +/// +/// If the input is already absolute, then the input is returned. If the input is not absolute, +/// then it is appended to the directory containing the source file with this macro invocation. +fn invocation_relative_path_to_absolute(span: Span, path: &str) -> PathBuf { + let path = Path::new(path); + if path.is_absolute() { + path.to_path_buf() + } else { + // `/a/b/c/foo/bar.rs` contains the current macro invocation + let mut source_file_path = span.source_file().path(); + // `/a/b/c/foo/` + source_file_path.pop(); + // `/a/b/c/foo/../locales/en-US/example.ftl` + source_file_path.push(path); + source_file_path + } +} + +/// Tokens to be returned when the macro cannot proceed. +fn failed(crate_name: &Ident) -> proc_macro::TokenStream { + quote! { + pub static DEFAULT_LOCALE_RESOURCE: &'static str = ""; + + #[allow(non_upper_case_globals)] + #[doc(hidden)] + pub(crate) mod fluent_generated { + pub mod #crate_name { + } + + pub mod _subdiag { + pub const help: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr(std::borrow::Cow::Borrowed("help")); + pub const note: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr(std::borrow::Cow::Borrowed("note")); + pub const warn: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr(std::borrow::Cow::Borrowed("warn")); + pub const label: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr(std::borrow::Cow::Borrowed("label")); + pub const suggestion: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr(std::borrow::Cow::Borrowed("suggestion")); + } + } + } + .into() +} + +/// See [rustc_fluent_macro::fluent_messages]. +pub(crate) fn fluent_messages(input: proc_macro::TokenStream) -> proc_macro::TokenStream { + let crate_name = std::env::var("CARGO_PKG_NAME") + // If `CARGO_PKG_NAME` is missing, then we're probably running in a test, so use + // `no_crate`. + .unwrap_or_else(|_| "no_crate".to_string()) + .replace("rustc_", ""); + + // Cannot iterate over individual messages in a bundle, so do that using the + // `FluentResource` instead. Construct a bundle anyway to find out if there are conflicting + // messages in the resources. + let mut bundle = FluentBundle::new(vec![langid!("en-US")]); + + // Set of Fluent attribute names already output, to avoid duplicate type errors - any given + // constant created for a given attribute is the same. + let mut previous_attrs = HashSet::new(); + + let resource_str = parse_macro_input!(input as LitStr); + let resource_span = resource_str.span().unwrap(); + let relative_ftl_path = resource_str.value(); + let absolute_ftl_path = invocation_relative_path_to_absolute(resource_span, &relative_ftl_path); + + let crate_name = Ident::new(&crate_name, resource_str.span()); + + // As this macro also outputs an `include_str!` for this file, the macro will always be + // re-executed when the file changes. + let resource_contents = match read_to_string(absolute_ftl_path) { + Ok(resource_contents) => resource_contents, + Err(e) => { + Diagnostic::spanned( + resource_span, + Level::Error, + format!("could not open Fluent resource: {e}"), + ) + .emit(); + return failed(&crate_name); + } + }; + let mut bad = false; + for esc in ["\\n", "\\\"", "\\'"] { + for _ in resource_contents.matches(esc) { + bad = true; + Diagnostic::spanned(resource_span, Level::Error, format!("invalid escape `{esc}` in Fluent resource")) + .note("Fluent does not interpret these escape sequences (<https://projectfluent.org/fluent/guide/special.html>)") + .emit(); + } + } + if bad { + return failed(&crate_name); + } + + let resource = match FluentResource::try_new(resource_contents) { + Ok(resource) => resource, + Err((this, errs)) => { + Diagnostic::spanned(resource_span, Level::Error, "could not parse Fluent resource") + .help("see additional errors emitted") + .emit(); + for ParserError { pos, slice: _, kind } in errs { + let mut err = kind.to_string(); + // Entirely unnecessary string modification so that the error message starts + // with a lowercase as rustc errors do. + err.replace_range(0..1, &err.chars().next().unwrap().to_lowercase().to_string()); + + let line_starts: Vec<usize> = std::iter::once(0) + .chain( + this.source() + .char_indices() + .filter_map(|(i, c)| Some(i + 1).filter(|_| c == '\n')), + ) + .collect(); + let line_start = line_starts + .iter() + .enumerate() + .map(|(line, idx)| (line + 1, idx)) + .filter(|(_, idx)| **idx <= pos.start) + .last() + .unwrap() + .0; + + let snippet = Snippet { + title: Some(Annotation { + label: Some(&err), + id: None, + annotation_type: AnnotationType::Error, + }), + footer: vec![], + slices: vec![Slice { + source: this.source(), + line_start, + origin: Some(&relative_ftl_path), + fold: true, + annotations: vec![SourceAnnotation { + label: "", + annotation_type: AnnotationType::Error, + range: (pos.start, pos.end - 1), + }], + }], + opt: Default::default(), + }; + let dl = DisplayList::from(snippet); + eprintln!("{dl}\n"); + } + + return failed(&crate_name); + } + }; + + let mut constants = TokenStream::new(); + let mut previous_defns = HashMap::new(); + let mut message_refs = Vec::new(); + for entry in resource.entries() { + if let Entry::Message(Message { id: Identifier { name }, attributes, value, .. }) = entry { + let _ = previous_defns.entry(name.to_string()).or_insert(resource_span); + if name.contains('-') { + Diagnostic::spanned( + resource_span, + Level::Error, + format!("name `{name}` contains a '-' character"), + ) + .help("replace any '-'s with '_'s") + .emit(); + } + + if let Some(Pattern { elements }) = value { + for elt in elements { + if let PatternElement::Placeable { + expression: + Expression::Inline(InlineExpression::MessageReference { id, .. }), + } = elt + { + message_refs.push((id.name, *name)); + } + } + } + + // `typeck_foo_bar` => `foo_bar` (in `typeck.ftl`) + // `const_eval_baz` => `baz` (in `const_eval.ftl`) + // `const-eval-hyphen-having` => `hyphen_having` (in `const_eval.ftl`) + // The last case we error about above, but we want to fall back gracefully + // so that only the error is being emitted and not also one about the macro + // failing. + let crate_prefix = format!("{crate_name}_"); + + let snake_name = name.replace('-', "_"); + if !snake_name.starts_with(&crate_prefix) { + Diagnostic::spanned( + resource_span, + Level::Error, + format!("name `{name}` does not start with the crate name"), + ) + .help(format!( + "prepend `{crate_prefix}` to the slug name: `{crate_prefix}{snake_name}`" + )) + .emit(); + }; + let snake_name = Ident::new(&snake_name, resource_str.span()); + + if !previous_attrs.insert(snake_name.clone()) { + continue; + } + + let msg = format!("Constant referring to Fluent message `{name}` from `{crate_name}`"); + constants.extend(quote! { + #[doc = #msg] + pub const #snake_name: crate::DiagnosticMessage = + crate::DiagnosticMessage::FluentIdentifier( + std::borrow::Cow::Borrowed(#name), + None + ); + }); + + for Attribute { id: Identifier { name: attr_name }, .. } in attributes { + let snake_name = Ident::new( + &format!("{}{}", &crate_prefix, &attr_name.replace('-', "_")), + resource_str.span(), + ); + if !previous_attrs.insert(snake_name.clone()) { + continue; + } + + if attr_name.contains('-') { + Diagnostic::spanned( + resource_span, + Level::Error, + format!("attribute `{attr_name}` contains a '-' character"), + ) + .help("replace any '-'s with '_'s") + .emit(); + } + + let msg = format!( + "Constant referring to Fluent message `{name}.{attr_name}` from `{crate_name}`" + ); + constants.extend(quote! { + #[doc = #msg] + pub const #snake_name: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr( + std::borrow::Cow::Borrowed(#attr_name) + ); + }); + } + } + } + + for (mref, name) in message_refs.into_iter() { + if !previous_defns.contains_key(mref) { + Diagnostic::spanned( + resource_span, + Level::Error, + format!("referenced message `{mref}` does not exist (in message `{name}`)"), + ) + .help(&format!("you may have meant to use a variable reference (`{{${mref}}}`)")) + .emit(); + } + } + + if let Err(errs) = bundle.add_resource(resource) { + for e in errs { + match e { + FluentError::Overriding { kind, id } => { + Diagnostic::spanned( + resource_span, + Level::Error, + format!("overrides existing {kind}: `{id}`"), + ) + .emit(); + } + FluentError::ResolverError(_) | FluentError::ParserError(_) => unreachable!(), + } + } + } + + quote! { + /// Raw content of Fluent resource for this crate, generated by `fluent_messages` macro, + /// imported by `rustc_driver` to include all crates' resources in one bundle. + pub static DEFAULT_LOCALE_RESOURCE: &'static str = include_str!(#relative_ftl_path); + + #[allow(non_upper_case_globals)] + #[doc(hidden)] + /// Auto-generated constants for type-checked references to Fluent messages. + pub(crate) mod fluent_generated { + #constants + + /// Constants expected to exist by the diagnostic derive macros to use as default Fluent + /// identifiers for different subdiagnostic kinds. + pub mod _subdiag { + /// Default for `#[help]` + pub const help: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr(std::borrow::Cow::Borrowed("help")); + /// Default for `#[note]` + pub const note: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr(std::borrow::Cow::Borrowed("note")); + /// Default for `#[warn]` + pub const warn: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr(std::borrow::Cow::Borrowed("warn")); + /// Default for `#[label]` + pub const label: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr(std::borrow::Cow::Borrowed("label")); + /// Default for `#[suggestion]` + pub const suggestion: crate::SubdiagnosticMessage = + crate::SubdiagnosticMessage::FluentAttr(std::borrow::Cow::Borrowed("suggestion")); + } + } + } + .into() +} diff --git a/compiler/rustc_fluent_macro/src/lib.rs b/compiler/rustc_fluent_macro/src/lib.rs new file mode 100644 index 000000000..a01643cd6 --- /dev/null +++ b/compiler/rustc_fluent_macro/src/lib.rs @@ -0,0 +1,64 @@ +#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")] +#![feature(proc_macro_diagnostic)] +#![feature(proc_macro_span)] +#![deny(rustc::untranslatable_diagnostic)] +#![deny(rustc::diagnostic_outside_of_impl)] +#![allow(rustc::default_hash_types)] + +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: DiagnosticMessage = +/// DiagnosticMessage::fluent("typeck_field_multiply_specified_in_initializer"); +/// pub const field_multiply_specified_in_initializer_label_previous_use: DiagnosticMessage = +/// DiagnosticMessage::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(); +/// ``` +#[proc_macro] +pub fn fluent_messages(input: TokenStream) -> TokenStream { + fluent::fluent_messages(input) +} |