| use std::cell::RefCell; |
| use std::collections::{BTreeSet, HashMap}; |
| use std::fmt; |
| use std::str::FromStr; |
| |
| use proc_macro::Span; |
| use proc_macro2::{Ident, TokenStream}; |
| use quote::{ToTokens, format_ident, quote}; |
| use syn::meta::ParseNestedMeta; |
| use syn::punctuated::Punctuated; |
| use syn::spanned::Spanned; |
| use syn::{Attribute, Field, LitStr, Meta, Path, Token, Type, TypeTuple, parenthesized}; |
| use synstructure::{BindingInfo, VariantInfo}; |
| |
| use super::error::invalid_attr; |
| use crate::diagnostics::error::{ |
| DiagnosticDeriveError, span_err, throw_invalid_attr, throw_span_err, |
| }; |
| |
| thread_local! { |
| pub(crate) static CODE_IDENT_COUNT: RefCell<u32> = RefCell::new(0); |
| } |
| |
| /// Returns an ident of the form `__code_N` where `N` is incremented once with every call. |
| pub(crate) fn new_code_ident() -> syn::Ident { |
| CODE_IDENT_COUNT.with(|count| { |
| let ident = format_ident!("__code_{}", *count.borrow()); |
| *count.borrow_mut() += 1; |
| ident |
| }) |
| } |
| |
| /// Checks whether the type name of `ty` matches `name`. |
| /// |
| /// Given some struct at `a::b::c::Foo`, this will return true for `c::Foo`, `b::c::Foo`, or |
| /// `a::b::c::Foo`. This reasonably allows qualified names to be used in the macro. |
| pub(crate) fn type_matches_path(ty: &Type, name: &[&str]) -> bool { |
| if let Type::Path(ty) = ty { |
| ty.path |
| .segments |
| .iter() |
| .map(|s| s.ident.to_string()) |
| .rev() |
| .zip(name.iter().rev()) |
| .all(|(x, y)| &x.as_str() == y) |
| } else { |
| false |
| } |
| } |
| |
| /// Checks whether the type `ty` is `()`. |
| pub(crate) fn type_is_unit(ty: &Type) -> bool { |
| if let Type::Tuple(TypeTuple { elems, .. }) = ty { elems.is_empty() } else { false } |
| } |
| |
| /// Checks whether the type `ty` is `bool`. |
| pub(crate) fn type_is_bool(ty: &Type) -> bool { |
| type_matches_path(ty, &["bool"]) |
| } |
| |
| /// Reports a type error for field with `attr`. |
| pub(crate) fn report_type_error( |
| attr: &Attribute, |
| ty_name: &str, |
| ) -> Result<!, DiagnosticDeriveError> { |
| let name = attr.path().segments.last().unwrap().ident.to_string(); |
| let meta = &attr.meta; |
| |
| throw_span_err!( |
| attr.span().unwrap(), |
| &format!( |
| "the `#[{}{}]` attribute can only be applied to fields of type {}", |
| name, |
| match meta { |
| Meta::Path(_) => "", |
| Meta::NameValue(_) => " = ...", |
| Meta::List(_) => "(...)", |
| }, |
| ty_name |
| ) |
| ); |
| } |
| |
| /// Reports an error if the field's type does not match `path`. |
| fn report_error_if_not_applied_to_ty( |
| attr: &Attribute, |
| info: &FieldInfo<'_>, |
| path: &[&str], |
| ty_name: &str, |
| ) -> Result<(), DiagnosticDeriveError> { |
| if !type_matches_path(info.ty.inner_type(), path) { |
| report_type_error(attr, ty_name)?; |
| } |
| |
| Ok(()) |
| } |
| |
| /// Reports an error if the field's type is not `Applicability`. |
| pub(crate) fn report_error_if_not_applied_to_applicability( |
| attr: &Attribute, |
| info: &FieldInfo<'_>, |
| ) -> Result<(), DiagnosticDeriveError> { |
| report_error_if_not_applied_to_ty( |
| attr, |
| info, |
| &["rustc_errors", "Applicability"], |
| "`Applicability`", |
| ) |
| } |
| |
| /// Reports an error if the field's type is not `Span`. |
| pub(crate) fn report_error_if_not_applied_to_span( |
| attr: &Attribute, |
| info: &FieldInfo<'_>, |
| ) -> Result<(), DiagnosticDeriveError> { |
| if !type_matches_path(info.ty.inner_type(), &["rustc_span", "Span"]) |
| && !type_matches_path(info.ty.inner_type(), &["rustc_errors", "MultiSpan"]) |
| { |
| report_type_error(attr, "`Span` or `MultiSpan`")?; |
| } |
| |
| Ok(()) |
| } |
| |
| /// Inner type of a field and type of wrapper. |
| #[derive(Copy, Clone)] |
| pub(crate) enum FieldInnerTy<'ty> { |
| /// Field is wrapped in a `Option<$inner>`. |
| Option(&'ty Type), |
| /// Field is wrapped in a `Vec<$inner>`. |
| Vec(&'ty Type), |
| /// Field isn't wrapped in an outer type. |
| Plain(&'ty Type), |
| } |
| |
| impl<'ty> FieldInnerTy<'ty> { |
| /// Returns inner type for a field, if there is one. |
| /// |
| /// - If `ty` is an `Option<Inner>`, returns `FieldInnerTy::Option(Inner)`. |
| /// - If `ty` is a `Vec<Inner>`, returns `FieldInnerTy::Vec(Inner)`. |
| /// - Otherwise returns `FieldInnerTy::Plain(ty)`. |
| pub(crate) fn from_type(ty: &'ty Type) -> Self { |
| fn single_generic_type(ty: &Type) -> &Type { |
| let Type::Path(ty_path) = ty else { |
| panic!("expected path type"); |
| }; |
| |
| let path = &ty_path.path; |
| let ty = path.segments.iter().last().unwrap(); |
| let syn::PathArguments::AngleBracketed(bracketed) = &ty.arguments else { |
| panic!("expected bracketed generic arguments"); |
| }; |
| |
| assert_eq!(bracketed.args.len(), 1); |
| |
| let syn::GenericArgument::Type(ty) = &bracketed.args[0] else { |
| panic!("expected generic parameter to be a type generic"); |
| }; |
| |
| ty |
| } |
| |
| if type_matches_path(ty, &["std", "option", "Option"]) { |
| FieldInnerTy::Option(single_generic_type(ty)) |
| } else if type_matches_path(ty, &["std", "vec", "Vec"]) { |
| FieldInnerTy::Vec(single_generic_type(ty)) |
| } else { |
| FieldInnerTy::Plain(ty) |
| } |
| } |
| |
| /// Returns `true` if `FieldInnerTy::with` will result in iteration for this inner type (i.e. |
| /// that cloning might be required for values moved in the loop body). |
| pub(crate) fn will_iterate(&self) -> bool { |
| match self { |
| FieldInnerTy::Vec(..) => true, |
| FieldInnerTy::Option(..) | FieldInnerTy::Plain(_) => false, |
| } |
| } |
| |
| /// Returns the inner type. |
| pub(crate) fn inner_type(&self) -> &'ty Type { |
| match self { |
| FieldInnerTy::Option(inner) | FieldInnerTy::Vec(inner) | FieldInnerTy::Plain(inner) => { |
| inner |
| } |
| } |
| } |
| |
| /// Surrounds `inner` with destructured wrapper type, exposing inner type as `binding`. |
| pub(crate) fn with(&self, binding: impl ToTokens, inner: impl ToTokens) -> TokenStream { |
| match self { |
| FieldInnerTy::Option(..) => quote! { |
| if let Some(#binding) = #binding { |
| #inner |
| } |
| }, |
| FieldInnerTy::Vec(..) => quote! { |
| for #binding in #binding { |
| #inner |
| } |
| }, |
| FieldInnerTy::Plain(t) if type_is_bool(t) => quote! { |
| if #binding { |
| #inner |
| } |
| }, |
| FieldInnerTy::Plain(..) => quote! { #inner }, |
| } |
| } |
| |
| pub(crate) fn span(&self) -> proc_macro2::Span { |
| match self { |
| FieldInnerTy::Option(ty) | FieldInnerTy::Vec(ty) | FieldInnerTy::Plain(ty) => ty.span(), |
| } |
| } |
| } |
| |
| /// Field information passed to the builder. Deliberately omits attrs to discourage the |
| /// `generate_*` methods from walking the attributes themselves. |
| pub(crate) struct FieldInfo<'a> { |
| pub(crate) binding: &'a BindingInfo<'a>, |
| pub(crate) ty: FieldInnerTy<'a>, |
| pub(crate) span: &'a proc_macro2::Span, |
| } |
| |
| /// Small helper trait for abstracting over `Option` fields that contain a value and a `Span` |
| /// for error reporting if they are set more than once. |
| pub(crate) trait SetOnce<T> { |
| fn set_once(&mut self, value: T, span: Span); |
| |
| fn value(self) -> Option<T>; |
| fn value_ref(&self) -> Option<&T>; |
| } |
| |
| /// An [`Option<T>`] that keeps track of the span that caused it to be set; used with [`SetOnce`]. |
| pub(super) type SpannedOption<T> = Option<(T, Span)>; |
| |
| impl<T> SetOnce<T> for SpannedOption<T> { |
| fn set_once(&mut self, value: T, span: Span) { |
| match self { |
| None => { |
| *self = Some((value, span)); |
| } |
| Some((_, prev_span)) => { |
| span_err(span, "attribute specified multiple times") |
| .span_note(*prev_span, "previously specified here") |
| .emit(); |
| } |
| } |
| } |
| |
| fn value(self) -> Option<T> { |
| self.map(|(v, _)| v) |
| } |
| |
| fn value_ref(&self) -> Option<&T> { |
| self.as_ref().map(|(v, _)| v) |
| } |
| } |
| |
| pub(super) type FieldMap = HashMap<String, TokenStream>; |
| |
| pub(crate) trait HasFieldMap { |
| /// Returns the binding for the field with the given name, if it exists on the type. |
| fn get_field_binding(&self, field: &String) -> Option<&TokenStream>; |
| |
| /// In the strings in the attributes supplied to this macro, we want callers to be able to |
| /// reference fields in the format string. For example: |
| /// |
| /// ```ignore (not-usage-example) |
| /// /// Suggest `==` when users wrote `===`. |
| /// #[suggestion(slug = "parser-not-javascript-eq", code = "{lhs} == {rhs}")] |
| /// struct NotJavaScriptEq { |
| /// #[primary_span] |
| /// span: Span, |
| /// lhs: Ident, |
| /// rhs: Ident, |
| /// } |
| /// ``` |
| /// |
| /// We want to automatically pick up that `{lhs}` refers `self.lhs` and `{rhs}` refers to |
| /// `self.rhs`, then generate this call to `format!`: |
| /// |
| /// ```ignore (not-usage-example) |
| /// format!("{lhs} == {rhs}", lhs = self.lhs, rhs = self.rhs) |
| /// ``` |
| /// |
| /// This function builds the entire call to `format!`. |
| fn build_format(&self, input: &str, span: proc_macro2::Span) -> TokenStream { |
| // This set is used later to generate the final format string. To keep builds reproducible, |
| // the iteration order needs to be deterministic, hence why we use a `BTreeSet` here |
| // instead of a `HashSet`. |
| let mut referenced_fields: BTreeSet<String> = BTreeSet::new(); |
| |
| // At this point, we can start parsing the format string. |
| let mut it = input.chars().peekable(); |
| |
| // Once the start of a format string has been found, process the format string and spit out |
| // the referenced fields. Leaves `it` sitting on the closing brace of the format string, so |
| // the next call to `it.next()` retrieves the next character. |
| while let Some(c) = it.next() { |
| if c != '{' { |
| continue; |
| } |
| if *it.peek().unwrap_or(&'\0') == '{' { |
| assert_eq!(it.next().unwrap(), '{'); |
| continue; |
| } |
| let mut eat_argument = || -> Option<String> { |
| let mut result = String::new(); |
| // Format specifiers look like: |
| // |
| // format := '{' [ argument ] [ ':' format_spec ] '}' . |
| // |
| // Therefore, we only need to eat until ':' or '}' to find the argument. |
| while let Some(c) = it.next() { |
| result.push(c); |
| let next = *it.peek().unwrap_or(&'\0'); |
| if next == '}' { |
| break; |
| } else if next == ':' { |
| // Eat the ':' character. |
| assert_eq!(it.next().unwrap(), ':'); |
| break; |
| } |
| } |
| // Eat until (and including) the matching '}' |
| while it.next()? != '}' { |
| continue; |
| } |
| Some(result) |
| }; |
| |
| if let Some(referenced_field) = eat_argument() { |
| referenced_fields.insert(referenced_field); |
| } |
| } |
| |
| // At this point, `referenced_fields` contains a set of the unique fields that were |
| // referenced in the format string. Generate the corresponding "x = self.x" format |
| // string parameters: |
| let args = referenced_fields.into_iter().map(|field: String| { |
| let field_ident = format_ident!("{}", field); |
| let value = match self.get_field_binding(&field) { |
| Some(value) => value.clone(), |
| // This field doesn't exist. Emit a diagnostic. |
| None => { |
| span_err( |
| span.unwrap(), |
| format!("`{field}` doesn't refer to a field on this type"), |
| ) |
| .emit(); |
| quote! { |
| "{#field}" |
| } |
| } |
| }; |
| quote! { |
| #field_ident = #value |
| } |
| }); |
| quote! { |
| format!(#input #(,#args)*) |
| } |
| } |
| } |
| |
| /// `Applicability` of a suggestion - mirrors `rustc_errors::Applicability` - and used to represent |
| /// the user's selection of applicability if specified in an attribute. |
| #[derive(Clone, Copy)] |
| pub(crate) enum Applicability { |
| MachineApplicable, |
| MaybeIncorrect, |
| HasPlaceholders, |
| Unspecified, |
| } |
| |
| impl FromStr for Applicability { |
| type Err = (); |
| |
| fn from_str(s: &str) -> Result<Self, Self::Err> { |
| match s { |
| "machine-applicable" => Ok(Applicability::MachineApplicable), |
| "maybe-incorrect" => Ok(Applicability::MaybeIncorrect), |
| "has-placeholders" => Ok(Applicability::HasPlaceholders), |
| "unspecified" => Ok(Applicability::Unspecified), |
| _ => Err(()), |
| } |
| } |
| } |
| |
| impl quote::ToTokens for Applicability { |
| fn to_tokens(&self, tokens: &mut TokenStream) { |
| tokens.extend(match self { |
| Applicability::MachineApplicable => { |
| quote! { rustc_errors::Applicability::MachineApplicable } |
| } |
| Applicability::MaybeIncorrect => { |
| quote! { rustc_errors::Applicability::MaybeIncorrect } |
| } |
| Applicability::HasPlaceholders => { |
| quote! { rustc_errors::Applicability::HasPlaceholders } |
| } |
| Applicability::Unspecified => { |
| quote! { rustc_errors::Applicability::Unspecified } |
| } |
| }); |
| } |
| } |
| |
| /// Build the mapping of field names to fields. This allows attributes to peek values from |
| /// other fields. |
| pub(super) fn build_field_mapping(variant: &VariantInfo<'_>) -> HashMap<String, TokenStream> { |
| let mut fields_map = FieldMap::new(); |
| for binding in variant.bindings() { |
| if let Some(ident) = &binding.ast().ident { |
| fields_map.insert(ident.to_string(), quote! { #binding }); |
| } |
| } |
| fields_map |
| } |
| |
| #[derive(Copy, Clone, Debug)] |
| pub(super) enum AllowMultipleAlternatives { |
| No, |
| Yes, |
| } |
| |
| fn parse_suggestion_values( |
| nested: ParseNestedMeta<'_>, |
| allow_multiple: AllowMultipleAlternatives, |
| ) -> syn::Result<Vec<LitStr>> { |
| let values = if let Ok(val) = nested.value() { |
| vec![val.parse()?] |
| } else { |
| let content; |
| parenthesized!(content in nested.input); |
| |
| if let AllowMultipleAlternatives::No = allow_multiple { |
| span_err( |
| nested.input.span().unwrap(), |
| "expected exactly one string literal for `code = ...`", |
| ) |
| .emit(); |
| vec![] |
| } else { |
| let literals = Punctuated::<LitStr, Token![,]>::parse_terminated(&content); |
| |
| match literals { |
| Ok(p) if p.is_empty() => { |
| span_err( |
| content.span().unwrap(), |
| "expected at least one string literal for `code(...)`", |
| ) |
| .emit(); |
| vec![] |
| } |
| Ok(p) => p.into_iter().collect(), |
| Err(_) => { |
| span_err( |
| content.span().unwrap(), |
| "`code(...)` must contain only string literals", |
| ) |
| .emit(); |
| vec![] |
| } |
| } |
| } |
| }; |
| |
| Ok(values) |
| } |
| |
| /// Constructs the `format!()` invocation(s) necessary for a `#[suggestion*(code = "foo")]` or |
| /// `#[suggestion*(code("foo", "bar"))]` attribute field |
| pub(super) fn build_suggestion_code( |
| code_field: &Ident, |
| nested: ParseNestedMeta<'_>, |
| fields: &impl HasFieldMap, |
| allow_multiple: AllowMultipleAlternatives, |
| ) -> TokenStream { |
| let values = match parse_suggestion_values(nested, allow_multiple) { |
| Ok(x) => x, |
| Err(e) => return e.into_compile_error(), |
| }; |
| |
| if let AllowMultipleAlternatives::Yes = allow_multiple { |
| let formatted_strings: Vec<_> = values |
| .into_iter() |
| .map(|value| fields.build_format(&value.value(), value.span())) |
| .collect(); |
| quote! { let #code_field = [#(#formatted_strings),*].into_iter(); } |
| } else if let [value] = values.as_slice() { |
| let formatted_str = fields.build_format(&value.value(), value.span()); |
| quote! { let #code_field = #formatted_str; } |
| } else { |
| // error handled previously |
| quote! { let #code_field = String::new(); } |
| } |
| } |
| |
| /// Possible styles for suggestion subdiagnostics. |
| #[derive(Clone, Copy, PartialEq)] |
| pub(super) enum SuggestionKind { |
| Normal, |
| Short, |
| Hidden, |
| Verbose, |
| ToolOnly, |
| } |
| |
| impl FromStr for SuggestionKind { |
| type Err = (); |
| |
| fn from_str(s: &str) -> Result<Self, Self::Err> { |
| match s { |
| "normal" => Ok(SuggestionKind::Normal), |
| "short" => Ok(SuggestionKind::Short), |
| "hidden" => Ok(SuggestionKind::Hidden), |
| "verbose" => Ok(SuggestionKind::Verbose), |
| "tool-only" => Ok(SuggestionKind::ToolOnly), |
| _ => Err(()), |
| } |
| } |
| } |
| |
| impl fmt::Display for SuggestionKind { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match self { |
| SuggestionKind::Normal => write!(f, "normal"), |
| SuggestionKind::Short => write!(f, "short"), |
| SuggestionKind::Hidden => write!(f, "hidden"), |
| SuggestionKind::Verbose => write!(f, "verbose"), |
| SuggestionKind::ToolOnly => write!(f, "tool-only"), |
| } |
| } |
| } |
| |
| impl SuggestionKind { |
| pub(crate) fn to_suggestion_style(&self) -> TokenStream { |
| match self { |
| SuggestionKind::Normal => { |
| quote! { rustc_errors::SuggestionStyle::ShowCode } |
| } |
| SuggestionKind::Short => { |
| quote! { rustc_errors::SuggestionStyle::HideCodeInline } |
| } |
| SuggestionKind::Hidden => { |
| quote! { rustc_errors::SuggestionStyle::HideCodeAlways } |
| } |
| SuggestionKind::Verbose => { |
| quote! { rustc_errors::SuggestionStyle::ShowAlways } |
| } |
| SuggestionKind::ToolOnly => { |
| quote! { rustc_errors::SuggestionStyle::CompletelyHidden } |
| } |
| } |
| } |
| |
| fn from_suffix(s: &str) -> Option<Self> { |
| match s { |
| "" => Some(SuggestionKind::Normal), |
| "_short" => Some(SuggestionKind::Short), |
| "_hidden" => Some(SuggestionKind::Hidden), |
| "_verbose" => Some(SuggestionKind::Verbose), |
| _ => None, |
| } |
| } |
| } |
| |
| /// Types of subdiagnostics that can be created using attributes |
| #[derive(Clone)] |
| pub(super) enum SubdiagnosticKind { |
| /// `#[label(...)]` |
| Label, |
| /// `#[note(...)]` |
| Note, |
| /// `#[note_once(...)]` |
| NoteOnce, |
| /// `#[help(...)]` |
| Help, |
| /// `#[help_once(...)]` |
| HelpOnce, |
| /// `#[warning(...)]` |
| Warn, |
| /// `#[suggestion{,_short,_hidden,_verbose}]` |
| Suggestion { |
| suggestion_kind: SuggestionKind, |
| applicability: SpannedOption<Applicability>, |
| /// Identifier for variable used for formatted code, e.g. `___code_0`. Enables separation |
| /// of formatting and diagnostic emission so that `arg` calls can happen in-between.. |
| code_field: syn::Ident, |
| /// Initialization logic for `code_field`'s variable, e.g. |
| /// `let __formatted_code = /* whatever */;` |
| code_init: TokenStream, |
| }, |
| /// `#[multipart_suggestion{,_short,_hidden,_verbose}]` |
| MultipartSuggestion { |
| suggestion_kind: SuggestionKind, |
| applicability: SpannedOption<Applicability>, |
| }, |
| } |
| |
| pub(super) struct SubdiagnosticVariant { |
| pub(super) kind: SubdiagnosticKind, |
| pub(super) slug: Option<Path>, |
| pub(super) no_span: bool, |
| } |
| |
| impl SubdiagnosticVariant { |
| /// Constructs a `SubdiagnosticVariant` from a field or type attribute such as `#[note]`, |
| /// `#[error(parser::add_paren, no_span)]` or `#[suggestion(code = "...")]`. Returns the |
| /// `SubdiagnosticKind` and the diagnostic slug, if specified. |
| pub(super) fn from_attr( |
| attr: &Attribute, |
| fields: &impl HasFieldMap, |
| ) -> Result<Option<SubdiagnosticVariant>, DiagnosticDeriveError> { |
| // Always allow documentation comments. |
| if is_doc_comment(attr) { |
| return Ok(None); |
| } |
| |
| let span = attr.span().unwrap(); |
| |
| let name = attr.path().segments.last().unwrap().ident.to_string(); |
| let name = name.as_str(); |
| |
| let mut kind = match name { |
| "label" => SubdiagnosticKind::Label, |
| "note" => SubdiagnosticKind::Note, |
| "note_once" => SubdiagnosticKind::NoteOnce, |
| "help" => SubdiagnosticKind::Help, |
| "help_once" => SubdiagnosticKind::HelpOnce, |
| "warning" => SubdiagnosticKind::Warn, |
| _ => { |
| // Recover old `#[(multipart_)suggestion_*]` syntaxes |
| // FIXME(#100717): remove |
| if let Some(suggestion_kind) = |
| name.strip_prefix("suggestion").and_then(SuggestionKind::from_suffix) |
| { |
| if suggestion_kind != SuggestionKind::Normal { |
| invalid_attr(attr) |
| .help(format!( |
| r#"Use `#[suggestion(..., style = "{suggestion_kind}")]` instead"# |
| )) |
| .emit(); |
| } |
| |
| SubdiagnosticKind::Suggestion { |
| suggestion_kind: SuggestionKind::Normal, |
| applicability: None, |
| code_field: new_code_ident(), |
| code_init: TokenStream::new(), |
| } |
| } else if let Some(suggestion_kind) = |
| name.strip_prefix("multipart_suggestion").and_then(SuggestionKind::from_suffix) |
| { |
| if suggestion_kind != SuggestionKind::Normal { |
| invalid_attr(attr) |
| .help(format!( |
| r#"Use `#[multipart_suggestion(..., style = "{suggestion_kind}")]` instead"# |
| )) |
| .emit(); |
| } |
| |
| SubdiagnosticKind::MultipartSuggestion { |
| suggestion_kind: SuggestionKind::Normal, |
| applicability: None, |
| } |
| } else { |
| throw_invalid_attr!(attr); |
| } |
| } |
| }; |
| |
| let list = match &attr.meta { |
| Meta::List(list) => { |
| // An attribute with properties, such as `#[suggestion(code = "...")]` or |
| // `#[error(some::slug)]` |
| list |
| } |
| Meta::Path(_) => { |
| // An attribute without a slug or other properties, such as `#[note]` - return |
| // without further processing. |
| // |
| // Only allow this if there are no mandatory properties, such as `code = "..."` in |
| // `#[suggestion(...)]` |
| match kind { |
| SubdiagnosticKind::Label |
| | SubdiagnosticKind::Note |
| | SubdiagnosticKind::NoteOnce |
| | SubdiagnosticKind::Help |
| | SubdiagnosticKind::HelpOnce |
| | SubdiagnosticKind::Warn |
| | SubdiagnosticKind::MultipartSuggestion { .. } => { |
| return Ok(Some(SubdiagnosticVariant { kind, slug: None, no_span: false })); |
| } |
| SubdiagnosticKind::Suggestion { .. } => { |
| throw_span_err!(span, "suggestion without `code = \"...\"`") |
| } |
| } |
| } |
| _ => { |
| throw_invalid_attr!(attr) |
| } |
| }; |
| |
| let mut code = None; |
| let mut suggestion_kind = None; |
| |
| let mut first = true; |
| let mut slug = None; |
| let mut no_span = false; |
| |
| list.parse_nested_meta(|nested| { |
| if nested.input.is_empty() || nested.input.peek(Token![,]) { |
| if first { |
| slug = Some(nested.path); |
| } else if nested.path.is_ident("no_span") { |
| no_span = true; |
| } else { |
| span_err(nested.input.span().unwrap(), "a diagnostic slug must be the first argument to the attribute").emit(); |
| } |
| |
| first = false; |
| return Ok(()); |
| } |
| |
| first = false; |
| |
| let nested_name = nested.path.segments.last().unwrap().ident.to_string(); |
| let nested_name = nested_name.as_str(); |
| |
| let path_span = nested.path.span().unwrap(); |
| let val_span = nested.input.span().unwrap(); |
| |
| macro_rules! get_string { |
| () => {{ |
| let Ok(value) = nested.value().and_then(|x| x.parse::<LitStr>()) else { |
| span_err(val_span, "expected `= \"xxx\"`").emit(); |
| return Ok(()); |
| }; |
| value |
| }}; |
| } |
| |
| let mut has_errors = false; |
| let input = nested.input; |
| |
| match (nested_name, &mut kind) { |
| ("code", SubdiagnosticKind::Suggestion { code_field, .. }) => { |
| let code_init = build_suggestion_code( |
| code_field, |
| nested, |
| fields, |
| AllowMultipleAlternatives::Yes, |
| ); |
| code.set_once(code_init, path_span); |
| } |
| ( |
| "applicability", |
| SubdiagnosticKind::Suggestion { ref mut applicability, .. } |
| | SubdiagnosticKind::MultipartSuggestion { ref mut applicability, .. }, |
| ) => { |
| let value = get_string!(); |
| let value = Applicability::from_str(&value.value()).unwrap_or_else(|()| { |
| span_err(value.span().unwrap(), "invalid applicability").emit(); |
| has_errors = true; |
| Applicability::Unspecified |
| }); |
| applicability.set_once(value, span); |
| } |
| ( |
| "style", |
| SubdiagnosticKind::Suggestion { .. } |
| | SubdiagnosticKind::MultipartSuggestion { .. }, |
| ) => { |
| let value = get_string!(); |
| |
| let value = value.value().parse().unwrap_or_else(|()| { |
| span_err(value.span().unwrap(), "invalid suggestion style") |
| .help("valid styles are `normal`, `short`, `hidden`, `verbose` and `tool-only`") |
| .emit(); |
| has_errors = true; |
| SuggestionKind::Normal |
| }); |
| |
| suggestion_kind.set_once(value, span); |
| } |
| |
| // Invalid nested attribute |
| (_, SubdiagnosticKind::Suggestion { .. }) => { |
| span_err(path_span, "invalid nested attribute") |
| .help( |
| "only `no_span`, `style`, `code` and `applicability` are valid nested attributes", |
| ) |
| .emit(); |
| has_errors = true; |
| } |
| (_, SubdiagnosticKind::MultipartSuggestion { .. }) => { |
| span_err(path_span, "invalid nested attribute") |
| .help("only `no_span`, `style` and `applicability` are valid nested attributes") |
| .emit(); |
| has_errors = true; |
| } |
| _ => { |
| span_err(path_span, "only `no_span` is a valid nested attribute").emit(); |
| has_errors = true; |
| } |
| } |
| |
| if has_errors { |
| // Consume the rest of the input to avoid spamming errors |
| let _ = input.parse::<TokenStream>(); |
| } |
| |
| Ok(()) |
| })?; |
| |
| match kind { |
| SubdiagnosticKind::Suggestion { |
| ref code_field, |
| ref mut code_init, |
| suggestion_kind: ref mut kind_field, |
| .. |
| } => { |
| if let Some(kind) = suggestion_kind.value() { |
| *kind_field = kind; |
| } |
| |
| *code_init = if let Some(init) = code.value() { |
| init |
| } else { |
| span_err(span, "suggestion without `code = \"...\"`").emit(); |
| quote! { let #code_field = std::iter::empty(); } |
| }; |
| } |
| SubdiagnosticKind::MultipartSuggestion { |
| suggestion_kind: ref mut kind_field, .. |
| } => { |
| if let Some(kind) = suggestion_kind.value() { |
| *kind_field = kind; |
| } |
| } |
| SubdiagnosticKind::Label |
| | SubdiagnosticKind::Note |
| | SubdiagnosticKind::NoteOnce |
| | SubdiagnosticKind::Help |
| | SubdiagnosticKind::HelpOnce |
| | SubdiagnosticKind::Warn => {} |
| } |
| |
| Ok(Some(SubdiagnosticVariant { kind, slug, no_span })) |
| } |
| } |
| |
| impl quote::IdentFragment for SubdiagnosticKind { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match self { |
| SubdiagnosticKind::Label => write!(f, "label"), |
| SubdiagnosticKind::Note => write!(f, "note"), |
| SubdiagnosticKind::NoteOnce => write!(f, "note_once"), |
| SubdiagnosticKind::Help => write!(f, "help"), |
| SubdiagnosticKind::HelpOnce => write!(f, "help_once"), |
| SubdiagnosticKind::Warn => write!(f, "warn"), |
| SubdiagnosticKind::Suggestion { .. } => write!(f, "suggestions_with_style"), |
| SubdiagnosticKind::MultipartSuggestion { .. } => { |
| write!(f, "multipart_suggestion_with_style") |
| } |
| } |
| } |
| |
| fn span(&self) -> Option<proc_macro2::Span> { |
| None |
| } |
| } |
| |
| /// Returns `true` if `field` should generate a `arg` call rather than any other diagnostic |
| /// call (like `span_label`). |
| pub(super) fn should_generate_arg(field: &Field) -> bool { |
| // Perhaps this should be an exhaustive list... |
| field.attrs.iter().all(|attr| is_doc_comment(attr)) |
| } |
| |
| pub(super) fn is_doc_comment(attr: &Attribute) -> bool { |
| attr.path().segments.last().unwrap().ident == "doc" |
| } |
