| pub use self::Level::*; |
| use rustc_ast::node_id::{NodeId, NodeMap}; |
| use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey}; |
| use rustc_errors::{pluralize, Applicability, DiagnosticBuilder}; |
| use rustc_span::edition::Edition; |
| use rustc_span::{sym, symbol::Ident, MultiSpan, Span, Symbol}; |
| |
| pub mod builtin; |
| |
| /// Setting for how to handle a lint. |
| #[derive(Clone, Copy, PartialEq, PartialOrd, Eq, Ord, Debug, Hash)] |
| pub enum Level { |
| Allow, |
| Warn, |
| Deny, |
| Forbid, |
| } |
| |
| rustc_data_structures::impl_stable_hash_via_hash!(Level); |
| |
| impl Level { |
| /// Converts a level to a lower-case string. |
| pub fn as_str(self) -> &'static str { |
| match self { |
| Level::Allow => "allow", |
| Level::Warn => "warn", |
| Level::Deny => "deny", |
| Level::Forbid => "forbid", |
| } |
| } |
| |
| /// Converts a lower-case string to a level. |
| pub fn from_str(x: &str) -> Option<Level> { |
| match x { |
| "allow" => Some(Level::Allow), |
| "warn" => Some(Level::Warn), |
| "deny" => Some(Level::Deny), |
| "forbid" => Some(Level::Forbid), |
| _ => None, |
| } |
| } |
| |
| /// Converts a symbol to a level. |
| pub fn from_symbol(x: Symbol) -> Option<Level> { |
| match x { |
| sym::allow => Some(Level::Allow), |
| sym::warn => Some(Level::Warn), |
| sym::deny => Some(Level::Deny), |
| sym::forbid => Some(Level::Forbid), |
| _ => None, |
| } |
| } |
| } |
| |
| /// Specification of a single lint. |
| #[derive(Copy, Clone, Debug)] |
| pub struct Lint { |
| /// A string identifier for the lint. |
| /// |
| /// This identifies the lint in attributes and in command-line arguments. |
| /// In those contexts it is always lowercase, but this field is compared |
| /// in a way which is case-insensitive for ASCII characters. This allows |
| /// `declare_lint!()` invocations to follow the convention of upper-case |
| /// statics without repeating the name. |
| /// |
| /// The name is written with underscores, e.g., "unused_imports". |
| /// On the command line, underscores become dashes. |
| pub name: &'static str, |
| |
| /// Default level for the lint. |
| pub default_level: Level, |
| |
| /// Description of the lint or the issue it detects. |
| /// |
| /// e.g., "imports that are never used" |
| pub desc: &'static str, |
| |
| /// Starting at the given edition, default to the given lint level. If this is `None`, then use |
| /// `default_level`. |
| pub edition_lint_opts: Option<(Edition, Level)>, |
| |
| /// `true` if this lint is reported even inside expansions of external macros. |
| pub report_in_external_macro: bool, |
| |
| pub future_incompatible: Option<FutureIncompatibleInfo>, |
| |
| pub is_plugin: bool, |
| |
| /// `Some` if this lint is feature gated, otherwise `None`. |
| pub feature_gate: Option<Symbol>, |
| |
| pub crate_level_only: bool, |
| } |
| |
| /// Extra information for a future incompatibility lint. |
| #[derive(Copy, Clone, Debug)] |
| pub struct FutureIncompatibleInfo { |
| /// e.g., a URL for an issue/PR/RFC or error code |
| pub reference: &'static str, |
| /// If this is an edition fixing lint, the edition in which |
| /// this lint becomes obsolete |
| pub edition: Option<Edition>, |
| } |
| |
| impl Lint { |
| pub const fn default_fields_for_macro() -> Self { |
| Lint { |
| name: "", |
| default_level: Level::Forbid, |
| desc: "", |
| edition_lint_opts: None, |
| is_plugin: false, |
| report_in_external_macro: false, |
| future_incompatible: None, |
| feature_gate: None, |
| crate_level_only: false, |
| } |
| } |
| |
| /// Gets the lint's name, with ASCII letters converted to lowercase. |
| pub fn name_lower(&self) -> String { |
| self.name.to_ascii_lowercase() |
| } |
| |
| pub fn default_level(&self, edition: Edition) -> Level { |
| self.edition_lint_opts |
| .filter(|(e, _)| *e <= edition) |
| .map(|(_, l)| l) |
| .unwrap_or(self.default_level) |
| } |
| } |
| |
| /// Identifies a lint known to the compiler. |
| #[derive(Clone, Copy, Debug)] |
| pub struct LintId { |
| // Identity is based on pointer equality of this field. |
| pub lint: &'static Lint, |
| } |
| |
| impl PartialEq for LintId { |
| fn eq(&self, other: &LintId) -> bool { |
| std::ptr::eq(self.lint, other.lint) |
| } |
| } |
| |
| impl Eq for LintId {} |
| |
| impl std::hash::Hash for LintId { |
| fn hash<H: std::hash::Hasher>(&self, state: &mut H) { |
| let ptr = self.lint as *const Lint; |
| ptr.hash(state); |
| } |
| } |
| |
| impl LintId { |
| /// Gets the `LintId` for a `Lint`. |
| pub fn of(lint: &'static Lint) -> LintId { |
| LintId { lint } |
| } |
| |
| pub fn lint_name_raw(&self) -> &'static str { |
| self.lint.name |
| } |
| |
| /// Gets the name of the lint. |
| pub fn to_string(&self) -> String { |
| self.lint.name_lower() |
| } |
| } |
| |
| impl<HCX> HashStable<HCX> for LintId { |
| #[inline] |
| fn hash_stable(&self, hcx: &mut HCX, hasher: &mut StableHasher) { |
| self.lint_name_raw().hash_stable(hcx, hasher); |
| } |
| } |
| |
| impl<HCX> ToStableHashKey<HCX> for LintId { |
| type KeyType = &'static str; |
| |
| #[inline] |
| fn to_stable_hash_key(&self, _: &HCX) -> &'static str { |
| self.lint_name_raw() |
| } |
| } |
| |
| // This could be a closure, but then implementing derive trait |
| // becomes hacky (and it gets allocated). |
| #[derive(PartialEq)] |
| pub enum BuiltinLintDiagnostics { |
| Normal, |
| BareTraitObject(Span, /* is_global */ bool), |
| AbsPathWithModule(Span), |
| ProcMacroDeriveResolutionFallback(Span), |
| MacroExpandedMacroExportsAccessedByAbsolutePaths(Span), |
| ElidedLifetimesInPaths(usize, Span, bool, Span, String), |
| UnknownCrateTypes(Span, String, String), |
| UnusedImports(String, Vec<(Span, String)>), |
| RedundantImport(Vec<(Span, bool)>, Ident), |
| DeprecatedMacro(Option<Symbol>, Span), |
| UnusedDocComment(Span), |
| } |
| |
| /// Lints that are buffered up early on in the `Session` before the |
| /// `LintLevels` is calculated. |
| #[derive(PartialEq)] |
| pub struct BufferedEarlyLint { |
| /// The span of code that we are linting on. |
| pub span: MultiSpan, |
| |
| /// The lint message. |
| pub msg: String, |
| |
| /// The `NodeId` of the AST node that generated the lint. |
| pub node_id: NodeId, |
| |
| /// A lint Id that can be passed to |
| /// `rustc_lint::early::EarlyContextAndPass::check_id`. |
| pub lint_id: LintId, |
| |
| /// Customization of the `DiagnosticBuilder<'_>` for the lint. |
| pub diagnostic: BuiltinLintDiagnostics, |
| } |
| |
| #[derive(Default)] |
| pub struct LintBuffer { |
| pub map: NodeMap<Vec<BufferedEarlyLint>>, |
| } |
| |
| impl LintBuffer { |
| pub fn add_early_lint(&mut self, early_lint: BufferedEarlyLint) { |
| let arr = self.map.entry(early_lint.node_id).or_default(); |
| if !arr.contains(&early_lint) { |
| arr.push(early_lint); |
| } |
| } |
| |
| pub fn add_lint( |
| &mut self, |
| lint: &'static Lint, |
| node_id: NodeId, |
| span: MultiSpan, |
| msg: &str, |
| diagnostic: BuiltinLintDiagnostics, |
| ) { |
| let lint_id = LintId::of(lint); |
| let msg = msg.to_string(); |
| self.add_early_lint(BufferedEarlyLint { lint_id, node_id, span, msg, diagnostic }); |
| } |
| |
| pub fn take(&mut self, id: NodeId) -> Vec<BufferedEarlyLint> { |
| self.map.remove(&id).unwrap_or_default() |
| } |
| |
| pub fn buffer_lint( |
| &mut self, |
| lint: &'static Lint, |
| id: NodeId, |
| sp: impl Into<MultiSpan>, |
| msg: &str, |
| ) { |
| self.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal) |
| } |
| |
| pub fn buffer_lint_with_diagnostic( |
| &mut self, |
| lint: &'static Lint, |
| id: NodeId, |
| sp: impl Into<MultiSpan>, |
| msg: &str, |
| diagnostic: BuiltinLintDiagnostics, |
| ) { |
| self.add_lint(lint, id, sp.into(), msg, diagnostic) |
| } |
| } |
| |
| /// Declares a static item of type `&'static Lint`. |
| #[macro_export] |
| macro_rules! declare_lint { |
| ($vis: vis $NAME: ident, $Level: ident, $desc: expr) => ( |
| $crate::declare_lint!( |
| $vis $NAME, $Level, $desc, |
| ); |
| ); |
| ($vis: vis $NAME: ident, $Level: ident, $desc: expr, |
| $(@future_incompatible = $fi:expr;)? |
| $(@feature_gate = $gate:expr;)? |
| $($v:ident),*) => ( |
| $vis static $NAME: &$crate::lint::Lint = &$crate::lint::Lint { |
| name: stringify!($NAME), |
| default_level: $crate::lint::$Level, |
| desc: $desc, |
| edition_lint_opts: None, |
| is_plugin: false, |
| $($v: true,)* |
| $(future_incompatible: Some($fi),)* |
| $(feature_gate: Some($gate),)* |
| ..$crate::lint::Lint::default_fields_for_macro() |
| }; |
| ); |
| ($vis: vis $NAME: ident, $Level: ident, $desc: expr, |
| $lint_edition: expr => $edition_level: ident |
| ) => ( |
| $vis static $NAME: &$crate::lint::Lint = &$crate::lint::Lint { |
| name: stringify!($NAME), |
| default_level: $crate::lint::$Level, |
| desc: $desc, |
| edition_lint_opts: Some(($lint_edition, $crate::lint::Level::$edition_level)), |
| report_in_external_macro: false, |
| is_plugin: false, |
| }; |
| ); |
| } |
| |
| #[macro_export] |
| macro_rules! declare_tool_lint { |
| ( |
| $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level: ident, $desc: expr |
| ) => ( |
| $crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, false} |
| ); |
| ( |
| $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr, |
| report_in_external_macro: $rep:expr |
| ) => ( |
| $crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, $rep} |
| ); |
| ( |
| $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr, |
| $external:expr |
| ) => ( |
| $(#[$attr])* |
| $vis static $NAME: &$crate::lint::Lint = &$crate::lint::Lint { |
| name: &concat!(stringify!($tool), "::", stringify!($NAME)), |
| default_level: $crate::lint::$Level, |
| desc: $desc, |
| edition_lint_opts: None, |
| report_in_external_macro: $external, |
| future_incompatible: None, |
| is_plugin: true, |
| feature_gate: None, |
| crate_level_only: false, |
| }; |
| ); |
| } |
| |
| /// Declares a static `LintArray` and return it as an expression. |
| #[macro_export] |
| macro_rules! lint_array { |
| ($( $lint:expr ),* ,) => { lint_array!( $($lint),* ) }; |
| ($( $lint:expr ),*) => {{ |
| vec![$($lint),*] |
| }} |
| } |
| |
| pub type LintArray = Vec<&'static Lint>; |
| |
| pub trait LintPass { |
| fn name(&self) -> &'static str; |
| } |
| |
| /// Implements `LintPass for $ty` with the given list of `Lint` statics. |
| #[macro_export] |
| macro_rules! impl_lint_pass { |
| ($ty:ty => [$($lint:expr),* $(,)?]) => { |
| impl $crate::lint::LintPass for $ty { |
| fn name(&self) -> &'static str { stringify!($ty) } |
| } |
| impl $ty { |
| pub fn get_lints() -> $crate::lint::LintArray { $crate::lint_array!($($lint),*) } |
| } |
| }; |
| } |
| |
| /// Declares a type named `$name` which implements `LintPass`. |
| /// To the right of `=>` a comma separated list of `Lint` statics is given. |
| #[macro_export] |
| macro_rules! declare_lint_pass { |
| ($(#[$m:meta])* $name:ident => [$($lint:expr),* $(,)?]) => { |
| $(#[$m])* #[derive(Copy, Clone)] pub struct $name; |
| $crate::impl_lint_pass!($name => [$($lint),*]); |
| }; |
| } |
| |
| pub fn add_elided_lifetime_in_path_suggestion( |
| sess: &crate::Session, |
| db: &mut DiagnosticBuilder<'_>, |
| n: usize, |
| path_span: Span, |
| incl_angl_brckt: bool, |
| insertion_span: Span, |
| anon_lts: String, |
| ) { |
| let (replace_span, suggestion) = if incl_angl_brckt { |
| (insertion_span, anon_lts) |
| } else { |
| // When possible, prefer a suggestion that replaces the whole |
| // `Path<T>` expression with `Path<'_, T>`, rather than inserting `'_, ` |
| // at a point (which makes for an ugly/confusing label) |
| if let Ok(snippet) = sess.source_map().span_to_snippet(path_span) { |
| // But our spans can get out of whack due to macros; if the place we think |
| // we want to insert `'_` isn't even within the path expression's span, we |
| // should bail out of making any suggestion rather than panicking on a |
| // subtract-with-overflow or string-slice-out-out-bounds (!) |
| // FIXME: can we do better? |
| if insertion_span.lo().0 < path_span.lo().0 { |
| return; |
| } |
| let insertion_index = (insertion_span.lo().0 - path_span.lo().0) as usize; |
| if insertion_index > snippet.len() { |
| return; |
| } |
| let (before, after) = snippet.split_at(insertion_index); |
| (path_span, format!("{}{}{}", before, anon_lts, after)) |
| } else { |
| (insertion_span, anon_lts) |
| } |
| }; |
| db.span_suggestion( |
| replace_span, |
| &format!("indicate the anonymous lifetime{}", pluralize!(n)), |
| suggestion, |
| Applicability::MachineApplicable, |
| ); |
| } |
