552 lines
17 KiB
Rust
552 lines
17 KiB
Rust
#[macro_use]
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extern crate rustc_macros;
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pub use self::Level::*;
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use rustc_ast::node_id::{NodeId, NodeMap};
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use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
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use rustc_serialize::json::Json;
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use rustc_span::edition::Edition;
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use rustc_span::{sym, symbol::Ident, MultiSpan, Span, Symbol};
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use rustc_target::spec::abi::Abi;
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pub mod builtin;
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#[macro_export]
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macro_rules! pluralize {
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($x:expr) => {
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if $x != 1 { "s" } else { "" }
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};
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}
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/// Indicates the confidence in the correctness of a suggestion.
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///
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/// All suggestions are marked with an `Applicability`. Tools use the applicability of a suggestion
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/// to determine whether it should be automatically applied or if the user should be consulted
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/// before applying the suggestion.
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#[derive(Copy, Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
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pub enum Applicability {
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/// The suggestion is definitely what the user intended, or maintains the exact meaning of the code.
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/// This suggestion should be automatically applied.
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///
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/// In case of multiple `MachineApplicable` suggestions (whether as part of
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/// the same `multipart_suggestion` or not), all of them should be
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/// automatically applied.
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MachineApplicable,
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/// The suggestion may be what the user intended, but it is uncertain. The suggestion should
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/// result in valid Rust code if it is applied.
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MaybeIncorrect,
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/// The suggestion contains placeholders like `(...)` or `{ /* fields */ }`. The suggestion
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/// cannot be applied automatically because it will not result in valid Rust code. The user
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/// will need to fill in the placeholders.
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HasPlaceholders,
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/// The applicability of the suggestion is unknown.
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Unspecified,
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}
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/// Setting for how to handle a lint.
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#[derive(Clone, Copy, PartialEq, PartialOrd, Eq, Ord, Debug, Hash)]
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pub enum Level {
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Allow,
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Warn,
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ForceWarn,
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Deny,
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Forbid,
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}
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rustc_data_structures::impl_stable_hash_via_hash!(Level);
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impl Level {
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/// Converts a level to a lower-case string.
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pub fn as_str(self) -> &'static str {
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match self {
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Level::Allow => "allow",
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Level::Warn => "warn",
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Level::ForceWarn => "force-warn",
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Level::Deny => "deny",
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Level::Forbid => "forbid",
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}
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}
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/// Converts a lower-case string to a level.
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pub fn from_str(x: &str) -> Option<Level> {
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match x {
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"allow" => Some(Level::Allow),
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"warn" => Some(Level::Warn),
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"deny" => Some(Level::Deny),
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"forbid" => Some(Level::Forbid),
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_ => None,
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}
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}
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/// Converts a symbol to a level.
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pub fn from_symbol(x: Symbol) -> Option<Level> {
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match x {
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sym::allow => Some(Level::Allow),
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sym::warn => Some(Level::Warn),
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sym::deny => Some(Level::Deny),
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sym::forbid => Some(Level::Forbid),
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_ => None,
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}
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}
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}
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/// Specification of a single lint.
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#[derive(Copy, Clone, Debug)]
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pub struct Lint {
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/// A string identifier for the lint.
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///
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/// This identifies the lint in attributes and in command-line arguments.
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/// In those contexts it is always lowercase, but this field is compared
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/// in a way which is case-insensitive for ASCII characters. This allows
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/// `declare_lint!()` invocations to follow the convention of upper-case
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/// statics without repeating the name.
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///
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/// The name is written with underscores, e.g., "unused_imports".
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/// On the command line, underscores become dashes.
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///
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/// See <https://rustc-dev-guide.rust-lang.org/diagnostics.html#lint-naming>
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/// for naming guidelines.
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pub name: &'static str,
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/// Default level for the lint.
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///
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/// See <https://rustc-dev-guide.rust-lang.org/diagnostics.html#diagnostic-levels>
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/// for guidelines on choosing a default level.
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pub default_level: Level,
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/// Description of the lint or the issue it detects.
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///
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/// e.g., "imports that are never used"
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pub desc: &'static str,
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/// Starting at the given edition, default to the given lint level. If this is `None`, then use
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/// `default_level`.
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pub edition_lint_opts: Option<(Edition, Level)>,
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/// `true` if this lint is reported even inside expansions of external macros.
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pub report_in_external_macro: bool,
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pub future_incompatible: Option<FutureIncompatibleInfo>,
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pub is_plugin: bool,
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/// `Some` if this lint is feature gated, otherwise `None`.
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pub feature_gate: Option<Symbol>,
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pub crate_level_only: bool,
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}
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/// Extra information for a future incompatibility lint.
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#[derive(Copy, Clone, Debug)]
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pub struct FutureIncompatibleInfo {
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/// e.g., a URL for an issue/PR/RFC or error code
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pub reference: &'static str,
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/// The reason for the lint used by diagnostics to provide
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/// the right help message
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pub reason: FutureIncompatibilityReason,
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/// Whether to explain the reason to the user.
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///
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/// Set to false for lints that already include a more detailed
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/// explanation.
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pub explain_reason: bool,
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}
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/// The reason for future incompatibility
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#[derive(Copy, Clone, Debug)]
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pub enum FutureIncompatibilityReason {
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/// This will be an error in a future release
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/// for all editions
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FutureReleaseError,
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/// This will be an error in a future release, and
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/// Cargo should create a report even for dependencies
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FutureReleaseErrorReportNow,
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/// Previously accepted code that will become an
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/// error in the provided edition
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EditionError(Edition),
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/// Code that changes meaning in some way in
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/// the provided edition
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EditionSemanticsChange(Edition),
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}
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impl FutureIncompatibilityReason {
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pub fn edition(self) -> Option<Edition> {
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match self {
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Self::EditionError(e) => Some(e),
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Self::EditionSemanticsChange(e) => Some(e),
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_ => None,
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}
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}
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}
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impl FutureIncompatibleInfo {
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pub const fn default_fields_for_macro() -> Self {
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FutureIncompatibleInfo {
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reference: "",
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reason: FutureIncompatibilityReason::FutureReleaseError,
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explain_reason: true,
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}
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}
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}
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impl Lint {
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pub const fn default_fields_for_macro() -> Self {
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Lint {
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name: "",
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default_level: Level::Forbid,
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desc: "",
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edition_lint_opts: None,
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is_plugin: false,
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report_in_external_macro: false,
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future_incompatible: None,
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feature_gate: None,
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crate_level_only: false,
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}
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}
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/// Gets the lint's name, with ASCII letters converted to lowercase.
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pub fn name_lower(&self) -> String {
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self.name.to_ascii_lowercase()
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}
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pub fn default_level(&self, edition: Edition) -> Level {
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self.edition_lint_opts
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.filter(|(e, _)| *e <= edition)
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.map(|(_, l)| l)
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.unwrap_or(self.default_level)
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}
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}
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/// Identifies a lint known to the compiler.
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#[derive(Clone, Copy, Debug)]
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pub struct LintId {
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// Identity is based on pointer equality of this field.
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pub lint: &'static Lint,
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}
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impl PartialEq for LintId {
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fn eq(&self, other: &LintId) -> bool {
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std::ptr::eq(self.lint, other.lint)
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}
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}
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impl Eq for LintId {}
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impl std::hash::Hash for LintId {
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fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
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let ptr = self.lint as *const Lint;
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ptr.hash(state);
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}
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}
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impl LintId {
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/// Gets the `LintId` for a `Lint`.
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pub fn of(lint: &'static Lint) -> LintId {
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LintId { lint }
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}
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pub fn lint_name_raw(&self) -> &'static str {
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self.lint.name
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}
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/// Gets the name of the lint.
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pub fn to_string(&self) -> String {
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self.lint.name_lower()
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}
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}
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impl<HCX> HashStable<HCX> for LintId {
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#[inline]
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fn hash_stable(&self, hcx: &mut HCX, hasher: &mut StableHasher) {
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self.lint_name_raw().hash_stable(hcx, hasher);
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}
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}
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impl<HCX> ToStableHashKey<HCX> for LintId {
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type KeyType = &'static str;
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#[inline]
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fn to_stable_hash_key(&self, _: &HCX) -> &'static str {
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self.lint_name_raw()
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}
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}
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// Duplicated from rustc_session::config::ExternDepSpec to avoid cyclic dependency
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#[derive(PartialEq, Debug)]
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pub enum ExternDepSpec {
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Json(Json),
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Raw(String),
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}
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// This could be a closure, but then implementing derive trait
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// becomes hacky (and it gets allocated).
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#[derive(PartialEq, Debug)]
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pub enum BuiltinLintDiagnostics {
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Normal,
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BareTraitObject(Span, /* is_global */ bool),
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AbsPathWithModule(Span),
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ProcMacroDeriveResolutionFallback(Span),
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MacroExpandedMacroExportsAccessedByAbsolutePaths(Span),
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ElidedLifetimesInPaths(usize, Span, bool, Span, String),
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UnknownCrateTypes(Span, String, String),
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UnusedImports(String, Vec<(Span, String)>),
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RedundantImport(Vec<(Span, bool)>, Ident),
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DeprecatedMacro(Option<Symbol>, Span),
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MissingAbi(Span, Abi),
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UnusedDocComment(Span),
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UnusedBuiltinAttribute { attr_name: Symbol, macro_name: String, invoc_span: Span },
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PatternsInFnsWithoutBody(Span, Ident),
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LegacyDeriveHelpers(Span),
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ExternDepSpec(String, ExternDepSpec),
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ProcMacroBackCompat(String),
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OrPatternsBackCompat(Span, String),
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ReservedPrefix(Span),
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TrailingMacro(bool, Ident),
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BreakWithLabelAndLoop(Span),
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NamedAsmLabel(String),
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}
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/// Lints that are buffered up early on in the `Session` before the
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/// `LintLevels` is calculated.
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#[derive(PartialEq)]
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pub struct BufferedEarlyLint {
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/// The span of code that we are linting on.
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pub span: MultiSpan,
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/// The lint message.
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pub msg: String,
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/// The `NodeId` of the AST node that generated the lint.
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pub node_id: NodeId,
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/// A lint Id that can be passed to
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/// `rustc_lint::early::EarlyContextAndPass::check_id`.
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pub lint_id: LintId,
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/// Customization of the `DiagnosticBuilder<'_>` for the lint.
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pub diagnostic: BuiltinLintDiagnostics,
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}
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#[derive(Default)]
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pub struct LintBuffer {
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pub map: NodeMap<Vec<BufferedEarlyLint>>,
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}
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impl LintBuffer {
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pub fn add_early_lint(&mut self, early_lint: BufferedEarlyLint) {
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let arr = self.map.entry(early_lint.node_id).or_default();
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if !arr.contains(&early_lint) {
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arr.push(early_lint);
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}
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}
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pub fn add_lint(
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&mut self,
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lint: &'static Lint,
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node_id: NodeId,
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span: MultiSpan,
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msg: &str,
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diagnostic: BuiltinLintDiagnostics,
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) {
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let lint_id = LintId::of(lint);
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let msg = msg.to_string();
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self.add_early_lint(BufferedEarlyLint { lint_id, node_id, span, msg, diagnostic });
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}
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pub fn take(&mut self, id: NodeId) -> Vec<BufferedEarlyLint> {
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self.map.remove(&id).unwrap_or_default()
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}
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pub fn buffer_lint(
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&mut self,
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lint: &'static Lint,
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id: NodeId,
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sp: impl Into<MultiSpan>,
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msg: &str,
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) {
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self.add_lint(lint, id, sp.into(), msg, BuiltinLintDiagnostics::Normal)
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}
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pub fn buffer_lint_with_diagnostic(
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&mut self,
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lint: &'static Lint,
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id: NodeId,
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sp: impl Into<MultiSpan>,
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msg: &str,
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diagnostic: BuiltinLintDiagnostics,
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) {
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self.add_lint(lint, id, sp.into(), msg, diagnostic)
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}
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}
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/// Declares a static item of type `&'static Lint`.
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///
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/// See <https://rustc-dev-guide.rust-lang.org/diagnostics.html> for
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/// documentation and guidelines on writing lints.
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///
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/// The macro call should start with a doc comment explaining the lint
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/// which will be embedded in the rustc user documentation book. It should
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/// be written in markdown and have a format that looks like this:
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///
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/// ```rust,ignore (doc-example)
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/// /// The `my_lint_name` lint detects [short explanation here].
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/// ///
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/// /// ### Example
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/// ///
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/// /// ```rust
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/// /// [insert a concise example that triggers the lint]
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/// /// ```
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/// ///
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/// /// {{produces}}
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/// ///
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/// /// ### Explanation
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/// ///
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/// /// This should be a detailed explanation of *why* the lint exists,
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/// /// and also include suggestions on how the user should fix the problem.
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/// /// Try to keep the text simple enough that a beginner can understand,
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/// /// and include links to other documentation for terminology that a
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/// /// beginner may not be familiar with. If this is "allow" by default,
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/// /// it should explain why (are there false positives or other issues?). If
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/// /// this is a future-incompatible lint, it should say so, with text that
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/// /// looks roughly like this:
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/// ///
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/// /// This is a [future-incompatible] lint to transition this to a hard
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/// /// error in the future. See [issue #xxxxx] for more details.
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/// ///
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/// /// [issue #xxxxx]: https://github.com/rust-lang/rust/issues/xxxxx
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/// ```
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///
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/// The `{{produces}}` tag will be automatically replaced with the output from
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/// the example by the build system. If the lint example is too complex to run
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/// as a simple example (for example, it needs an extern crate), mark the code
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/// block with `ignore` and manually replace the `{{produces}}` line with the
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/// expected output in a `text` code block.
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///
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/// If this is a rustdoc-only lint, then only include a brief introduction
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/// with a link with the text `[rustdoc book]` so that the validator knows
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/// that this is for rustdoc only (see BROKEN_INTRA_DOC_LINKS as an example).
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///
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/// Commands to view and test the documentation:
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///
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/// * `./x.py doc --stage=1 src/doc/rustc --open`: Builds the rustc book and opens it.
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/// * `./x.py test src/tools/lint-docs`: Validates that the lint docs have the
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/// correct style, and that the code example actually emits the expected
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/// lint.
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///
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/// If you have already built the compiler, and you want to make changes to
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/// just the doc comments, then use the `--keep-stage=0` flag with the above
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/// commands to avoid rebuilding the compiler.
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#[macro_export]
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macro_rules! declare_lint {
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($(#[$attr:meta])* $vis: vis $NAME: ident, $Level: ident, $desc: expr) => (
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$crate::declare_lint!(
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$(#[$attr])* $vis $NAME, $Level, $desc,
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);
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);
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($(#[$attr:meta])* $vis: vis $NAME: ident, $Level: ident, $desc: expr,
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$(@feature_gate = $gate:expr;)?
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$(@future_incompatible = FutureIncompatibleInfo { $($field:ident : $val:expr),* $(,)* }; )?
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$($v:ident),*) => (
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$(#[$attr])*
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$vis static $NAME: &$crate::Lint = &$crate::Lint {
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name: stringify!($NAME),
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default_level: $crate::$Level,
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desc: $desc,
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edition_lint_opts: None,
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is_plugin: false,
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$($v: true,)*
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$(feature_gate: Some($gate),)*
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$(future_incompatible: Some($crate::FutureIncompatibleInfo {
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$($field: $val,)*
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..$crate::FutureIncompatibleInfo::default_fields_for_macro()
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}),)*
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..$crate::Lint::default_fields_for_macro()
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};
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);
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($(#[$attr:meta])* $vis: vis $NAME: ident, $Level: ident, $desc: expr,
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$lint_edition: expr => $edition_level: ident
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) => (
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$(#[$attr])*
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$vis static $NAME: &$crate::Lint = &$crate::Lint {
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name: stringify!($NAME),
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default_level: $crate::$Level,
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desc: $desc,
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edition_lint_opts: Some(($lint_edition, $crate::Level::$edition_level)),
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report_in_external_macro: false,
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is_plugin: false,
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};
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);
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}
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#[macro_export]
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macro_rules! declare_tool_lint {
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(
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$(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level: ident, $desc: expr
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) => (
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$crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, false}
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);
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(
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$(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr,
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report_in_external_macro: $rep:expr
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) => (
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$crate::declare_tool_lint!{$(#[$attr])* $vis $tool::$NAME, $Level, $desc, $rep}
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);
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(
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$(#[$attr:meta])* $vis:vis $tool:ident ::$NAME:ident, $Level:ident, $desc:expr,
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$external:expr
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) => (
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$(#[$attr])*
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$vis static $NAME: &$crate::Lint = &$crate::Lint {
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name: &concat!(stringify!($tool), "::", stringify!($NAME)),
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default_level: $crate::$Level,
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|
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::LintPass for $ty {
|
|
fn name(&self) -> &'static str { stringify!($ty) }
|
|
}
|
|
impl $ty {
|
|
pub fn get_lints() -> $crate::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),*]);
|
|
};
|
|
}
|