| //! Lints, aka compiler warnings. |
| //! |
| //! A 'lint' check is a kind of miscellaneous constraint that a user _might_ |
| //! want to enforce, but might reasonably want to permit as well, on a |
| //! module-by-module basis. They contrast with static constraints enforced by |
| //! other phases of the compiler, which are generally required to hold in order |
| //! to compile the program at all. |
| //! |
| //! Most lints can be written as `LintPass` instances. These run after |
| //! all other analyses. The `LintPass`es built into rustc are defined |
| //! within `builtin.rs`, which has further comments on how to add such a lint. |
| //! rustc can also load user-defined lint plugins via the plugin mechanism. |
| //! |
| //! Some of rustc's lints are defined elsewhere in the compiler and work by |
| //! calling `add_lint()` on the overall `Session` object. This works when |
| //! it happens before the main lint pass, which emits the lints stored by |
| //! `add_lint()`. To emit lints after the main lint pass (from codegen, for |
| //! example) requires more effort. See `emit_lint` and `GatherNodeLevels` |
| //! in `context.rs`. |
| |
| pub use self::Level::*; |
| pub use self::LintSource::*; |
| |
| use rustc_data_structures::sync; |
| |
| use crate::hir::def_id::{CrateNum, LOCAL_CRATE}; |
| use crate::hir::intravisit; |
| use crate::hir; |
| use crate::lint::builtin::BuiltinLintDiagnostics; |
| use crate::lint::builtin::parser::{ILL_FORMED_ATTRIBUTE_INPUT, META_VARIABLE_MISUSE}; |
| use crate::lint::builtin::parser::INCOMPLETE_INCLUDE; |
| use crate::session::{Session, DiagnosticMessageId}; |
| use crate::ty::TyCtxt; |
| use crate::ty::query::Providers; |
| use crate::util::nodemap::NodeMap; |
| use errors::{DiagnosticBuilder, DiagnosticId}; |
| use std::{hash, ptr}; |
| use syntax::ast; |
| use syntax::source_map::{MultiSpan, ExpnKind, DesugaringKind}; |
| use syntax::early_buffered_lints::BufferedEarlyLintId; |
| use syntax::edition::Edition; |
| use syntax::symbol::{Symbol, sym}; |
| use syntax_pos::hygiene::MacroKind; |
| use syntax_pos::Span; |
| |
| pub use crate::lint::context::{LateContext, EarlyContext, LintContext, LintStore, |
| check_crate, check_ast_crate, late_lint_mod, CheckLintNameResult, |
| BufferedEarlyLint,}; |
| |
| /// 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, |
| } |
| |
| /// 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, |
| } |
| } |
| |
| /// Returns the `rust::lint::Lint` for a `syntax::early_buffered_lints::BufferedEarlyLintId`. |
| pub fn from_parser_lint_id(lint_id: BufferedEarlyLintId) -> &'static Self { |
| match lint_id { |
| BufferedEarlyLintId::IllFormedAttributeInput => ILL_FORMED_ATTRIBUTE_INPUT, |
| BufferedEarlyLintId::MetaVariableMisuse => META_VARIABLE_MISUSE, |
| BufferedEarlyLintId::IncompleteInclude => INCOMPLETE_INCLUDE, |
| } |
| } |
| |
| /// 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, session: &Session) -> Level { |
| self.edition_lint_opts |
| .filter(|(e, _)| *e <= session.edition()) |
| .map(|(_, l)| l) |
| .unwrap_or(self.default_level) |
| } |
| } |
| |
| /// Declares a static item of type `&'static Lint`. |
| #[macro_export] |
| macro_rules! declare_lint { |
| ($vis: vis $NAME: ident, $Level: ident, $desc: expr) => ( |
| declare_lint!( |
| $vis $NAME, $Level, $desc, |
| ); |
| ); |
| ($vis: vis $NAME: ident, $Level: ident, $desc: expr, |
| $(@future_incompatible = $fi: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),)* |
| ..$crate::lint::Lint::default_fields_for_macro() |
| }; |
| ); |
| ($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, $desc: expr |
| ) => ( |
| declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, false} |
| ); |
| ( |
| $(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr, |
| report_in_external_macro: $rep:expr |
| ) => ( |
| declare_tool_lint!{$(#[$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: $external, |
| future_incompatible: None, |
| is_plugin: true, |
| }; |
| ); |
| } |
| |
| /// Declares a static `LintArray` and return it as an expression. |
| #[macro_export] |
| macro_rules! lint_array { |
| ($( $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 $name` with the given list of `Lint` statics. |
| #[macro_export] |
| macro_rules! impl_lint_pass { |
| ($name:ident => [$($lint:expr),* $(,)?]) => { |
| impl LintPass for $name { |
| fn name(&self) -> &'static str { stringify!($name) } |
| } |
| impl $name { |
| pub fn get_lints() -> 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),*]); |
| }; |
| } |
| |
| #[macro_export] |
| macro_rules! late_lint_methods { |
| ($macro:path, $args:tt, [$hir:tt]) => ( |
| $macro!($args, [$hir], [ |
| fn check_param(a: &$hir hir::Param); |
| fn check_body(a: &$hir hir::Body); |
| fn check_body_post(a: &$hir hir::Body); |
| fn check_name(a: Span, b: ast::Name); |
| fn check_crate(a: &$hir hir::Crate); |
| fn check_crate_post(a: &$hir hir::Crate); |
| fn check_mod(a: &$hir hir::Mod, b: Span, c: hir::HirId); |
| fn check_mod_post(a: &$hir hir::Mod, b: Span, c: hir::HirId); |
| fn check_foreign_item(a: &$hir hir::ForeignItem); |
| fn check_foreign_item_post(a: &$hir hir::ForeignItem); |
| fn check_item(a: &$hir hir::Item); |
| fn check_item_post(a: &$hir hir::Item); |
| fn check_local(a: &$hir hir::Local); |
| fn check_block(a: &$hir hir::Block); |
| fn check_block_post(a: &$hir hir::Block); |
| fn check_stmt(a: &$hir hir::Stmt); |
| fn check_arm(a: &$hir hir::Arm); |
| fn check_pat(a: &$hir hir::Pat); |
| fn check_expr(a: &$hir hir::Expr); |
| fn check_expr_post(a: &$hir hir::Expr); |
| fn check_ty(a: &$hir hir::Ty); |
| fn check_generic_param(a: &$hir hir::GenericParam); |
| fn check_generics(a: &$hir hir::Generics); |
| fn check_where_predicate(a: &$hir hir::WherePredicate); |
| fn check_poly_trait_ref(a: &$hir hir::PolyTraitRef, b: hir::TraitBoundModifier); |
| fn check_fn( |
| a: hir::intravisit::FnKind<$hir>, |
| b: &$hir hir::FnDecl, |
| c: &$hir hir::Body, |
| d: Span, |
| e: hir::HirId); |
| fn check_fn_post( |
| a: hir::intravisit::FnKind<$hir>, |
| b: &$hir hir::FnDecl, |
| c: &$hir hir::Body, |
| d: Span, |
| e: hir::HirId |
| ); |
| fn check_trait_item(a: &$hir hir::TraitItem); |
| fn check_trait_item_post(a: &$hir hir::TraitItem); |
| fn check_impl_item(a: &$hir hir::ImplItem); |
| fn check_impl_item_post(a: &$hir hir::ImplItem); |
| fn check_struct_def(a: &$hir hir::VariantData); |
| fn check_struct_def_post(a: &$hir hir::VariantData); |
| fn check_struct_field(a: &$hir hir::StructField); |
| fn check_variant(a: &$hir hir::Variant); |
| fn check_variant_post(a: &$hir hir::Variant); |
| fn check_lifetime(a: &$hir hir::Lifetime); |
| fn check_path(a: &$hir hir::Path, b: hir::HirId); |
| fn check_attribute(a: &$hir ast::Attribute); |
| |
| /// Called when entering a syntax node that can have lint attributes such |
| /// as `#[allow(...)]`. Called with *all* the attributes of that node. |
| fn enter_lint_attrs(a: &$hir [ast::Attribute]); |
| |
| /// Counterpart to `enter_lint_attrs`. |
| fn exit_lint_attrs(a: &$hir [ast::Attribute]); |
| ]); |
| ) |
| } |
| |
| /// Trait for types providing lint checks. |
| /// |
| /// Each `check` method checks a single syntax node, and should not |
| /// invoke methods recursively (unlike `Visitor`). By default they |
| /// do nothing. |
| // |
| // FIXME: eliminate the duplication with `Visitor`. But this also |
| // contains a few lint-specific methods with no equivalent in `Visitor`. |
| |
| macro_rules! expand_lint_pass_methods { |
| ($context:ty, [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => ( |
| $(#[inline(always)] fn $name(&mut self, _: $context, $(_: $arg),*) {})* |
| ) |
| } |
| |
| macro_rules! declare_late_lint_pass { |
| ([], [$hir:tt], [$($methods:tt)*]) => ( |
| pub trait LateLintPass<'a, $hir>: LintPass { |
| expand_lint_pass_methods!(&LateContext<'a, $hir>, [$($methods)*]); |
| } |
| ) |
| } |
| |
| late_lint_methods!(declare_late_lint_pass, [], ['tcx]); |
| |
| #[macro_export] |
| macro_rules! expand_combined_late_lint_pass_method { |
| ([$($passes:ident),*], $self: ident, $name: ident, $params:tt) => ({ |
| $($self.$passes.$name $params;)* |
| }) |
| } |
| |
| #[macro_export] |
| macro_rules! expand_combined_late_lint_pass_methods { |
| ($passes:tt, [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => ( |
| $(fn $name(&mut self, context: &LateContext<'a, 'tcx>, $($param: $arg),*) { |
| expand_combined_late_lint_pass_method!($passes, self, $name, (context, $($param),*)); |
| })* |
| ) |
| } |
| |
| #[macro_export] |
| macro_rules! declare_combined_late_lint_pass { |
| ([$v:vis $name:ident, [$($passes:ident: $constructor:expr,)*]], [$hir:tt], $methods:tt) => ( |
| #[allow(non_snake_case)] |
| $v struct $name { |
| $($passes: $passes,)* |
| } |
| |
| impl $name { |
| $v fn new() -> Self { |
| Self { |
| $($passes: $constructor,)* |
| } |
| } |
| |
| $v fn get_lints() -> LintArray { |
| let mut lints = Vec::new(); |
| $(lints.extend_from_slice(&$passes::get_lints());)* |
| lints |
| } |
| } |
| |
| impl<'a, 'tcx> LateLintPass<'a, 'tcx> for $name { |
| expand_combined_late_lint_pass_methods!([$($passes),*], $methods); |
| } |
| |
| impl LintPass for $name { |
| fn name(&self) -> &'static str { |
| panic!() |
| } |
| } |
| ) |
| } |
| |
| #[macro_export] |
| macro_rules! early_lint_methods { |
| ($macro:path, $args:tt) => ( |
| $macro!($args, [ |
| fn check_param(a: &ast::Param); |
| fn check_ident(a: ast::Ident); |
| fn check_crate(a: &ast::Crate); |
| fn check_crate_post(a: &ast::Crate); |
| fn check_mod(a: &ast::Mod, b: Span, c: ast::NodeId); |
| fn check_mod_post(a: &ast::Mod, b: Span, c: ast::NodeId); |
| fn check_foreign_item(a: &ast::ForeignItem); |
| fn check_foreign_item_post(a: &ast::ForeignItem); |
| fn check_item(a: &ast::Item); |
| fn check_item_post(a: &ast::Item); |
| fn check_local(a: &ast::Local); |
| fn check_block(a: &ast::Block); |
| fn check_block_post(a: &ast::Block); |
| fn check_stmt(a: &ast::Stmt); |
| fn check_arm(a: &ast::Arm); |
| fn check_pat(a: &ast::Pat); |
| fn check_pat_post(a: &ast::Pat); |
| fn check_expr(a: &ast::Expr); |
| fn check_expr_post(a: &ast::Expr); |
| fn check_ty(a: &ast::Ty); |
| fn check_generic_param(a: &ast::GenericParam); |
| fn check_generics(a: &ast::Generics); |
| fn check_where_predicate(a: &ast::WherePredicate); |
| fn check_poly_trait_ref(a: &ast::PolyTraitRef, |
| b: &ast::TraitBoundModifier); |
| fn check_fn(a: syntax::visit::FnKind<'_>, b: &ast::FnDecl, c: Span, d_: ast::NodeId); |
| fn check_fn_post( |
| a: syntax::visit::FnKind<'_>, |
| b: &ast::FnDecl, |
| c: Span, |
| d: ast::NodeId |
| ); |
| fn check_trait_item(a: &ast::TraitItem); |
| fn check_trait_item_post(a: &ast::TraitItem); |
| fn check_impl_item(a: &ast::ImplItem); |
| fn check_impl_item_post(a: &ast::ImplItem); |
| fn check_struct_def(a: &ast::VariantData); |
| fn check_struct_def_post(a: &ast::VariantData); |
| fn check_struct_field(a: &ast::StructField); |
| fn check_variant(a: &ast::Variant); |
| fn check_variant_post(a: &ast::Variant); |
| fn check_lifetime(a: &ast::Lifetime); |
| fn check_path(a: &ast::Path, b: ast::NodeId); |
| fn check_attribute(a: &ast::Attribute); |
| fn check_mac_def(a: &ast::MacroDef, b: ast::NodeId); |
| fn check_mac(a: &ast::Mac); |
| |
| /// Called when entering a syntax node that can have lint attributes such |
| /// as `#[allow(...)]`. Called with *all* the attributes of that node. |
| fn enter_lint_attrs(a: &[ast::Attribute]); |
| |
| /// Counterpart to `enter_lint_attrs`. |
| fn exit_lint_attrs(a: &[ast::Attribute]); |
| ]); |
| ) |
| } |
| |
| macro_rules! expand_early_lint_pass_methods { |
| ($context:ty, [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => ( |
| $(#[inline(always)] fn $name(&mut self, _: $context, $(_: $arg),*) {})* |
| ) |
| } |
| |
| macro_rules! declare_early_lint_pass { |
| ([], [$($methods:tt)*]) => ( |
| pub trait EarlyLintPass: LintPass { |
| expand_early_lint_pass_methods!(&EarlyContext<'_>, [$($methods)*]); |
| } |
| ) |
| } |
| |
| early_lint_methods!(declare_early_lint_pass, []); |
| |
| #[macro_export] |
| macro_rules! expand_combined_early_lint_pass_method { |
| ([$($passes:ident),*], $self: ident, $name: ident, $params:tt) => ({ |
| $($self.$passes.$name $params;)* |
| }) |
| } |
| |
| #[macro_export] |
| macro_rules! expand_combined_early_lint_pass_methods { |
| ($passes:tt, [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => ( |
| $(fn $name(&mut self, context: &EarlyContext<'_>, $($param: $arg),*) { |
| expand_combined_early_lint_pass_method!($passes, self, $name, (context, $($param),*)); |
| })* |
| ) |
| } |
| |
| #[macro_export] |
| macro_rules! declare_combined_early_lint_pass { |
| ([$v:vis $name:ident, [$($passes:ident: $constructor:expr,)*]], $methods:tt) => ( |
| #[allow(non_snake_case)] |
| $v struct $name { |
| $($passes: $passes,)* |
| } |
| |
| impl $name { |
| $v fn new() -> Self { |
| Self { |
| $($passes: $constructor,)* |
| } |
| } |
| |
| $v fn get_lints() -> LintArray { |
| let mut lints = Vec::new(); |
| $(lints.extend_from_slice(&$passes::get_lints());)* |
| lints |
| } |
| } |
| |
| impl EarlyLintPass for $name { |
| expand_combined_early_lint_pass_methods!([$($passes),*], $methods); |
| } |
| |
| impl LintPass for $name { |
| fn name(&self) -> &'static str { |
| panic!() |
| } |
| } |
| ) |
| } |
| |
| /// A lint pass boxed up as a trait object. |
| pub type EarlyLintPassObject = Box<dyn EarlyLintPass + sync::Send + sync::Sync + 'static>; |
| pub type LateLintPassObject = Box<dyn for<'a, 'tcx> LateLintPass<'a, 'tcx> + sync::Send |
| + sync::Sync + 'static>; |
| |
| /// Identifies a lint known to the compiler. |
| #[derive(Clone, Copy, Debug)] |
| pub struct LintId { |
| // Identity is based on pointer equality of this field. |
| lint: &'static Lint, |
| } |
| |
| impl PartialEq for LintId { |
| fn eq(&self, other: &LintId) -> bool { |
| ptr::eq(self.lint, other.lint) |
| } |
| } |
| |
| impl Eq for LintId { } |
| |
| impl hash::Hash for LintId { |
| fn hash<H: 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() |
| } |
| } |
| |
| /// Setting for how to handle a lint. |
| #[derive(Clone, Copy, PartialEq, PartialOrd, Eq, Ord, Debug, Hash, HashStable)] |
| pub enum Level { |
| Allow, Warn, Deny, Forbid, |
| } |
| |
| impl Level { |
| /// Converts a level to a lower-case string. |
| pub fn as_str(self) -> &'static str { |
| match self { |
| Allow => "allow", |
| Warn => "warn", |
| Deny => "deny", |
| Forbid => "forbid", |
| } |
| } |
| |
| /// Converts a lower-case string to a level. |
| pub fn from_str(x: &str) -> Option<Level> { |
| match x { |
| "allow" => Some(Allow), |
| "warn" => Some(Warn), |
| "deny" => Some(Deny), |
| "forbid" => Some(Forbid), |
| _ => None, |
| } |
| } |
| |
| /// Converts a symbol to a level. |
| pub fn from_symbol(x: Symbol) -> Option<Level> { |
| match x { |
| sym::allow => Some(Allow), |
| sym::warn => Some(Warn), |
| sym::deny => Some(Deny), |
| sym::forbid => Some(Forbid), |
| _ => None, |
| } |
| } |
| } |
| |
| /// How a lint level was set. |
| #[derive(Clone, Copy, PartialEq, Eq, HashStable)] |
| pub enum LintSource { |
| /// Lint is at the default level as declared |
| /// in rustc or a plugin. |
| Default, |
| |
| /// Lint level was set by an attribute. |
| Node(ast::Name, Span, Option<Symbol> /* RFC 2383 reason */), |
| |
| /// Lint level was set by a command-line flag. |
| CommandLine(Symbol), |
| } |
| |
| pub type LevelSource = (Level, LintSource); |
| |
| pub mod builtin; |
| pub mod internal; |
| mod context; |
| mod levels; |
| |
| pub use self::levels::{LintLevelSets, LintLevelMap}; |
| |
| #[derive(Default)] |
| pub struct LintBuffer { |
| map: NodeMap<Vec<BufferedEarlyLint>>, |
| } |
| |
| impl LintBuffer { |
| pub fn add_lint(&mut self, |
| lint: &'static Lint, |
| id: ast::NodeId, |
| sp: MultiSpan, |
| msg: &str, |
| diagnostic: BuiltinLintDiagnostics) { |
| let early_lint = BufferedEarlyLint { |
| lint_id: LintId::of(lint), |
| ast_id: id, |
| span: sp, |
| msg: msg.to_string(), |
| diagnostic |
| }; |
| let arr = self.map.entry(id).or_default(); |
| if !arr.contains(&early_lint) { |
| arr.push(early_lint); |
| } |
| } |
| |
| fn take(&mut self, id: ast::NodeId) -> Vec<BufferedEarlyLint> { |
| self.map.remove(&id).unwrap_or_default() |
| } |
| |
| pub fn buffer_lint<S: Into<MultiSpan>>( |
| &mut self, |
| lint: &'static Lint, |
| id: ast::NodeId, |
| sp: S, |
| msg: &str, |
| ) { |
| self.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal) |
| } |
| |
| pub fn buffer_lint_with_diagnostic<S: Into<MultiSpan>>( |
| &mut self, |
| lint: &'static Lint, |
| id: ast::NodeId, |
| sp: S, |
| msg: &str, |
| diagnostic: BuiltinLintDiagnostics, |
| ) { |
| self.add_lint(lint, id, sp.into(), msg, diagnostic) |
| } |
| } |
| |
| pub fn struct_lint_level<'a>(sess: &'a Session, |
| lint: &'static Lint, |
| level: Level, |
| src: LintSource, |
| span: Option<MultiSpan>, |
| msg: &str) |
| -> DiagnosticBuilder<'a> |
| { |
| let mut err = match (level, span) { |
| (Level::Allow, _) => return sess.diagnostic().struct_dummy(), |
| (Level::Warn, Some(span)) => sess.struct_span_warn(span, msg), |
| (Level::Warn, None) => sess.struct_warn(msg), |
| (Level::Deny, Some(span)) | |
| (Level::Forbid, Some(span)) => sess.struct_span_err(span, msg), |
| (Level::Deny, None) | |
| (Level::Forbid, None) => sess.struct_err(msg), |
| }; |
| |
| // Check for future incompatibility lints and issue a stronger warning. |
| let lint_id = LintId::of(lint); |
| let future_incompatible = lint.future_incompatible; |
| |
| // If this code originates in a foreign macro, aka something that this crate |
| // did not itself author, then it's likely that there's nothing this crate |
| // can do about it. We probably want to skip the lint entirely. |
| if err.span.primary_spans().iter().any(|s| in_external_macro(sess, *s)) { |
| // Any suggestions made here are likely to be incorrect, so anything we |
| // emit shouldn't be automatically fixed by rustfix. |
| err.allow_suggestions(false); |
| |
| // If this is a future incompatible lint it'll become a hard error, so |
| // we have to emit *something*. Also allow lints to whitelist themselves |
| // on a case-by-case basis for emission in a foreign macro. |
| if future_incompatible.is_none() && !lint.report_in_external_macro { |
| err.cancel(); |
| // Don't continue further, since we don't want to have |
| // `diag_span_note_once` called for a diagnostic that isn't emitted. |
| return err; |
| } |
| } |
| |
| let name = lint.name_lower(); |
| match src { |
| LintSource::Default => { |
| sess.diag_note_once( |
| &mut err, |
| DiagnosticMessageId::from(lint), |
| &format!("`#[{}({})]` on by default", level.as_str(), name)); |
| } |
| LintSource::CommandLine(lint_flag_val) => { |
| let flag = match level { |
| Level::Warn => "-W", |
| Level::Deny => "-D", |
| Level::Forbid => "-F", |
| Level::Allow => panic!(), |
| }; |
| let hyphen_case_lint_name = name.replace("_", "-"); |
| if lint_flag_val.as_str() == name { |
| sess.diag_note_once( |
| &mut err, |
| DiagnosticMessageId::from(lint), |
| &format!("requested on the command line with `{} {}`", |
| flag, hyphen_case_lint_name)); |
| } else { |
| let hyphen_case_flag_val = lint_flag_val.as_str().replace("_", "-"); |
| sess.diag_note_once( |
| &mut err, |
| DiagnosticMessageId::from(lint), |
| &format!("`{} {}` implied by `{} {}`", |
| flag, hyphen_case_lint_name, flag, |
| hyphen_case_flag_val)); |
| } |
| } |
| LintSource::Node(lint_attr_name, src, reason) => { |
| if let Some(rationale) = reason { |
| err.note(&rationale.as_str()); |
| } |
| sess.diag_span_note_once(&mut err, DiagnosticMessageId::from(lint), |
| src, "lint level defined here"); |
| if lint_attr_name.as_str() != name { |
| let level_str = level.as_str(); |
| sess.diag_note_once(&mut err, DiagnosticMessageId::from(lint), |
| &format!("`#[{}({})]` implied by `#[{}({})]`", |
| level_str, name, level_str, lint_attr_name)); |
| } |
| } |
| } |
| |
| err.code(DiagnosticId::Lint(name)); |
| |
| if let Some(future_incompatible) = future_incompatible { |
| const STANDARD_MESSAGE: &str = |
| "this was previously accepted by the compiler but is being phased out; \ |
| it will become a hard error"; |
| |
| let explanation = if lint_id == LintId::of(builtin::UNSTABLE_NAME_COLLISIONS) { |
| "once this method is added to the standard library, \ |
| the ambiguity may cause an error or change in behavior!" |
| .to_owned() |
| } else if lint_id == LintId::of(builtin::MUTABLE_BORROW_RESERVATION_CONFLICT) { |
| "this borrowing pattern was not meant to be accepted, \ |
| and may become a hard error in the future" |
| .to_owned() |
| } else if let Some(edition) = future_incompatible.edition { |
| format!("{} in the {} edition!", STANDARD_MESSAGE, edition) |
| } else { |
| format!("{} in a future release!", STANDARD_MESSAGE) |
| }; |
| let citation = format!("for more information, see {}", |
| future_incompatible.reference); |
| err.warn(&explanation); |
| err.note(&citation); |
| } |
| |
| return err |
| } |
| |
| pub fn maybe_lint_level_root(tcx: TyCtxt<'_>, id: hir::HirId) -> bool { |
| let attrs = tcx.hir().attrs(id); |
| attrs.iter().any(|attr| Level::from_symbol(attr.name_or_empty()).is_some()) |
| } |
| |
| fn lint_levels(tcx: TyCtxt<'_>, cnum: CrateNum) -> &LintLevelMap { |
| assert_eq!(cnum, LOCAL_CRATE); |
| let store = &tcx.lint_store; |
| let mut builder = LintLevelMapBuilder { |
| levels: LintLevelSets::builder(tcx.sess, false, &store), |
| tcx: tcx, |
| store: store, |
| }; |
| let krate = tcx.hir().krate(); |
| |
| let push = builder.levels.push(&krate.attrs, &store); |
| builder.levels.register_id(hir::CRATE_HIR_ID); |
| for macro_def in &krate.exported_macros { |
| builder.levels.register_id(macro_def.hir_id); |
| } |
| intravisit::walk_crate(&mut builder, krate); |
| builder.levels.pop(push); |
| |
| tcx.arena.alloc(builder.levels.build_map()) |
| } |
| |
| struct LintLevelMapBuilder<'a, 'tcx> { |
| levels: levels::LintLevelsBuilder<'tcx>, |
| tcx: TyCtxt<'tcx>, |
| store: &'a LintStore, |
| } |
| |
| impl LintLevelMapBuilder<'_, '_> { |
| fn with_lint_attrs<F>(&mut self, |
| id: hir::HirId, |
| attrs: &[ast::Attribute], |
| f: F) |
| where F: FnOnce(&mut Self) |
| { |
| let push = self.levels.push(attrs, self.store); |
| if push.changed { |
| self.levels.register_id(id); |
| } |
| f(self); |
| self.levels.pop(push); |
| } |
| } |
| |
| impl intravisit::Visitor<'tcx> for LintLevelMapBuilder<'_, 'tcx> { |
| fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, 'tcx> { |
| intravisit::NestedVisitorMap::All(&self.tcx.hir()) |
| } |
| |
| fn visit_param(&mut self, param: &'tcx hir::Param) { |
| self.with_lint_attrs(param.hir_id, ¶m.attrs, |builder| { |
| intravisit::walk_param(builder, param); |
| }); |
| } |
| |
| fn visit_item(&mut self, it: &'tcx hir::Item) { |
| self.with_lint_attrs(it.hir_id, &it.attrs, |builder| { |
| intravisit::walk_item(builder, it); |
| }); |
| } |
| |
| fn visit_foreign_item(&mut self, it: &'tcx hir::ForeignItem) { |
| self.with_lint_attrs(it.hir_id, &it.attrs, |builder| { |
| intravisit::walk_foreign_item(builder, it); |
| }) |
| } |
| |
| fn visit_expr(&mut self, e: &'tcx hir::Expr) { |
| self.with_lint_attrs(e.hir_id, &e.attrs, |builder| { |
| intravisit::walk_expr(builder, e); |
| }) |
| } |
| |
| fn visit_struct_field(&mut self, s: &'tcx hir::StructField) { |
| self.with_lint_attrs(s.hir_id, &s.attrs, |builder| { |
| intravisit::walk_struct_field(builder, s); |
| }) |
| } |
| |
| fn visit_variant(&mut self, |
| v: &'tcx hir::Variant, |
| g: &'tcx hir::Generics, |
| item_id: hir::HirId) { |
| self.with_lint_attrs(v.id, &v.attrs, |builder| { |
| intravisit::walk_variant(builder, v, g, item_id); |
| }) |
| } |
| |
| fn visit_local(&mut self, l: &'tcx hir::Local) { |
| self.with_lint_attrs(l.hir_id, &l.attrs, |builder| { |
| intravisit::walk_local(builder, l); |
| }) |
| } |
| |
| fn visit_arm(&mut self, a: &'tcx hir::Arm) { |
| self.with_lint_attrs(a.hir_id, &a.attrs, |builder| { |
| intravisit::walk_arm(builder, a); |
| }) |
| } |
| |
| fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem) { |
| self.with_lint_attrs(trait_item.hir_id, &trait_item.attrs, |builder| { |
| intravisit::walk_trait_item(builder, trait_item); |
| }); |
| } |
| |
| fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) { |
| self.with_lint_attrs(impl_item.hir_id, &impl_item.attrs, |builder| { |
| intravisit::walk_impl_item(builder, impl_item); |
| }); |
| } |
| } |
| |
| pub fn provide(providers: &mut Providers<'_>) { |
| providers.lint_levels = lint_levels; |
| } |
| |
| /// Returns whether `span` originates in a foreign crate's external macro. |
| /// |
| /// This is used to test whether a lint should not even begin to figure out whether it should |
| /// be reported on the current node. |
| pub fn in_external_macro(sess: &Session, span: Span) -> bool { |
| let expn_data = span.ctxt().outer_expn_data(); |
| match expn_data.kind { |
| ExpnKind::Root | ExpnKind::Desugaring(DesugaringKind::ForLoop) => false, |
| ExpnKind::AstPass(_) | ExpnKind::Desugaring(_) => true, // well, it's "external" |
| ExpnKind::Macro(MacroKind::Bang, _) => { |
| if expn_data.def_site.is_dummy() { |
| // Dummy span for the `def_site` means it's an external macro. |
| return true; |
| } |
| match sess.source_map().span_to_snippet(expn_data.def_site) { |
| Ok(code) => !code.starts_with("macro_rules"), |
| // No snippet means external macro or compiler-builtin expansion. |
| Err(_) => true, |
| } |
| } |
| ExpnKind::Macro(..) => true, // definitely a plugin |
| } |
| } |
| |
| /// Returns `true` if `span` originates in a derive-macro's expansion. |
| pub fn in_derive_expansion(span: Span) -> bool { |
| if let ExpnKind::Macro(MacroKind::Derive, _) = span.ctxt().outer_expn_data().kind { |
| return true; |
| } |
| false |
| } |
