1213 lines
46 KiB
Rust
1213 lines
46 KiB
Rust
//! Parsing and validation of builtin attributes
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use rustc_ast as ast;
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use rustc_ast::{Attribute, Lit, LitKind, MetaItem, MetaItemKind, NestedMetaItem, NodeId};
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use rustc_ast_pretty::pprust;
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use rustc_feature::{find_gated_cfg, is_builtin_attr_name, Features, GatedCfg};
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use rustc_macros::HashStable_Generic;
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use rustc_session::lint::builtin::UNEXPECTED_CFGS;
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use rustc_session::lint::BuiltinLintDiagnostics;
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use rustc_session::parse::{feature_err, ParseSess};
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use rustc_session::Session;
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use rustc_span::hygiene::Transparency;
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use rustc_span::{symbol::sym, symbol::Symbol, Span};
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use std::num::NonZeroU32;
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use crate::session_diagnostics::{self, IncorrectReprFormatGenericCause};
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/// The version placeholder that recently stabilized features contain inside the
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/// `since` field of the `#[stable]` attribute.
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///
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/// For more, see [this pull request](https://github.com/rust-lang/rust/pull/100591).
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pub const VERSION_PLACEHOLDER: &str = "CURRENT_RUSTC_VERSION";
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pub fn rust_version_symbol() -> Symbol {
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let version = option_env!("CFG_VERSION").unwrap_or("<current>");
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let version = version.split(' ').next().unwrap();
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Symbol::intern(&version)
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}
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pub fn is_builtin_attr(attr: &Attribute) -> bool {
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attr.is_doc_comment() || attr.ident().filter(|ident| is_builtin_attr_name(ident.name)).is_some()
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}
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enum AttrError {
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MultipleItem(String),
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UnknownMetaItem(String, &'static [&'static str]),
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MissingSince,
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NonIdentFeature,
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MissingFeature,
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MultipleStabilityLevels,
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UnsupportedLiteral(UnsupportedLiteralReason, /* is_bytestr */ bool),
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}
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pub(crate) enum UnsupportedLiteralReason {
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Generic,
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CfgString,
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DeprecatedString,
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DeprecatedKvPair,
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}
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fn handle_errors(sess: &ParseSess, span: Span, error: AttrError) {
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match error {
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AttrError::MultipleItem(item) => {
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sess.emit_err(session_diagnostics::MultipleItem { span, item });
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}
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AttrError::UnknownMetaItem(item, expected) => {
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sess.emit_err(session_diagnostics::UnknownMetaItem { span, item, expected });
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}
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AttrError::MissingSince => {
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sess.emit_err(session_diagnostics::MissingSince { span });
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}
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AttrError::NonIdentFeature => {
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sess.emit_err(session_diagnostics::NonIdentFeature { span });
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}
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AttrError::MissingFeature => {
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sess.emit_err(session_diagnostics::MissingFeature { span });
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}
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AttrError::MultipleStabilityLevels => {
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sess.emit_err(session_diagnostics::MultipleStabilityLevels { span });
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}
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AttrError::UnsupportedLiteral(reason, is_bytestr) => {
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sess.emit_err(session_diagnostics::UnsupportedLiteral {
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span,
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reason,
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is_bytestr,
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start_point_span: sess.source_map().start_point(span),
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});
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}
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}
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}
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#[derive(Copy, Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
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pub enum InlineAttr {
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None,
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Hint,
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Always,
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Never,
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}
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#[derive(Clone, Encodable, Decodable, Debug, PartialEq, Eq, HashStable_Generic)]
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pub enum InstructionSetAttr {
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ArmA32,
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ArmT32,
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}
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#[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
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pub enum OptimizeAttr {
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None,
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Speed,
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Size,
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}
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/// Represents the following attributes:
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///
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/// - `#[stable]`
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/// - `#[unstable]`
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#[derive(Encodable, Decodable, Copy, Clone, Debug, PartialEq, Eq, Hash)]
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#[derive(HashStable_Generic)]
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pub struct Stability {
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pub level: StabilityLevel,
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pub feature: Symbol,
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}
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impl Stability {
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pub fn is_unstable(&self) -> bool {
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self.level.is_unstable()
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}
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pub fn is_stable(&self) -> bool {
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self.level.is_stable()
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}
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}
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/// Represents the `#[rustc_const_unstable]` and `#[rustc_const_stable]` attributes.
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#[derive(Encodable, Decodable, Copy, Clone, Debug, PartialEq, Eq, Hash)]
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#[derive(HashStable_Generic)]
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pub struct ConstStability {
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pub level: StabilityLevel,
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pub feature: Symbol,
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/// whether the function has a `#[rustc_promotable]` attribute
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pub promotable: bool,
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}
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impl ConstStability {
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pub fn is_const_unstable(&self) -> bool {
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self.level.is_unstable()
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}
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pub fn is_const_stable(&self) -> bool {
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self.level.is_stable()
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}
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}
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/// Represents the `#[rustc_default_body_unstable]` attribute.
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#[derive(Encodable, Decodable, Copy, Clone, Debug, PartialEq, Eq, Hash)]
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#[derive(HashStable_Generic)]
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pub struct DefaultBodyStability {
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pub level: StabilityLevel,
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pub feature: Symbol,
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}
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/// The available stability levels.
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#[derive(Encodable, Decodable, PartialEq, Copy, Clone, Debug, Eq, Hash)]
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#[derive(HashStable_Generic)]
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pub enum StabilityLevel {
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/// `#[unstable]`
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Unstable {
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/// Reason for the current stability level.
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reason: UnstableReason,
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/// Relevant `rust-lang/rust` issue.
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issue: Option<NonZeroU32>,
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is_soft: bool,
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/// If part of a feature is stabilized and a new feature is added for the remaining parts,
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/// then the `implied_by` attribute is used to indicate which now-stable feature previously
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/// contained a item.
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///
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/// ```pseudo-Rust
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/// #[unstable(feature = "foo", issue = "...")]
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/// fn foo() {}
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/// #[unstable(feature = "foo", issue = "...")]
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/// fn foobar() {}
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/// ```
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///
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/// ...becomes...
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///
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/// ```pseudo-Rust
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/// #[stable(feature = "foo", since = "1.XX.X")]
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/// fn foo() {}
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/// #[unstable(feature = "foobar", issue = "...", implied_by = "foo")]
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/// fn foobar() {}
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/// ```
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implied_by: Option<Symbol>,
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},
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/// `#[stable]`
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Stable {
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/// Rust release which stabilized this feature.
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since: Symbol,
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/// Is this item allowed to be referred to on stable, despite being contained in unstable
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/// modules?
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allowed_through_unstable_modules: bool,
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},
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}
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impl StabilityLevel {
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pub fn is_unstable(&self) -> bool {
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matches!(self, StabilityLevel::Unstable { .. })
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}
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pub fn is_stable(&self) -> bool {
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matches!(self, StabilityLevel::Stable { .. })
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}
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}
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#[derive(Encodable, Decodable, PartialEq, Copy, Clone, Debug, Eq, Hash)]
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#[derive(HashStable_Generic)]
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pub enum UnstableReason {
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None,
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Default,
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Some(Symbol),
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}
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impl UnstableReason {
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fn from_opt_reason(reason: Option<Symbol>) -> Self {
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// UnstableReason::Default constructed manually
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match reason {
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Some(r) => Self::Some(r),
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None => Self::None,
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}
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}
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pub fn to_opt_reason(&self) -> Option<Symbol> {
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match self {
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Self::None => None,
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Self::Default => Some(sym::unstable_location_reason_default),
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Self::Some(r) => Some(*r),
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}
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}
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}
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/// Collects stability info from all stability attributes in `attrs`.
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/// Returns `None` if no stability attributes are found.
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pub fn find_stability(
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sess: &Session,
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attrs: &[Attribute],
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item_sp: Span,
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) -> (Option<(Stability, Span)>, Option<(ConstStability, Span)>, Option<(DefaultBodyStability, Span)>)
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{
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find_stability_generic(sess, attrs.iter(), item_sp)
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}
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fn find_stability_generic<'a, I>(
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sess: &Session,
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attrs_iter: I,
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item_sp: Span,
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) -> (Option<(Stability, Span)>, Option<(ConstStability, Span)>, Option<(DefaultBodyStability, Span)>)
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where
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I: Iterator<Item = &'a Attribute>,
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{
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use StabilityLevel::*;
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let mut stab: Option<(Stability, Span)> = None;
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let mut const_stab: Option<(ConstStability, Span)> = None;
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let mut body_stab: Option<(DefaultBodyStability, Span)> = None;
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let mut promotable = false;
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let mut allowed_through_unstable_modules = false;
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'outer: for attr in attrs_iter {
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if ![
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sym::rustc_const_unstable,
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sym::rustc_const_stable,
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sym::unstable,
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sym::stable,
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sym::rustc_promotable,
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sym::rustc_allowed_through_unstable_modules,
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sym::rustc_default_body_unstable,
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]
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.iter()
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.any(|&s| attr.has_name(s))
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{
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continue; // not a stability level
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}
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let meta = attr.meta();
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if attr.has_name(sym::rustc_promotable) {
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promotable = true;
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} else if attr.has_name(sym::rustc_allowed_through_unstable_modules) {
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allowed_through_unstable_modules = true;
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}
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// attributes with data
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else if let Some(MetaItem { kind: MetaItemKind::List(ref metas), .. }) = meta {
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let meta = meta.as_ref().unwrap();
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let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
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if item.is_some() {
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handle_errors(
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&sess.parse_sess,
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meta.span,
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AttrError::MultipleItem(pprust::path_to_string(&meta.path)),
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);
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return false;
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}
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if let Some(v) = meta.value_str() {
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*item = Some(v);
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true
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} else {
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sess.emit_err(session_diagnostics::IncorrectMetaItem { span: meta.span });
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false
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}
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};
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let meta_name = meta.name_or_empty();
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match meta_name {
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sym::rustc_const_unstable | sym::rustc_default_body_unstable | sym::unstable => {
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if meta_name == sym::unstable && stab.is_some() {
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handle_errors(
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&sess.parse_sess,
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attr.span,
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AttrError::MultipleStabilityLevels,
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);
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break;
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} else if meta_name == sym::rustc_const_unstable && const_stab.is_some() {
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handle_errors(
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&sess.parse_sess,
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attr.span,
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AttrError::MultipleStabilityLevels,
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);
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break;
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} else if meta_name == sym::rustc_default_body_unstable && body_stab.is_some() {
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handle_errors(
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&sess.parse_sess,
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attr.span,
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AttrError::MultipleStabilityLevels,
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);
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break;
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}
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let mut feature = None;
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let mut reason = None;
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let mut issue = None;
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let mut issue_num = None;
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let mut is_soft = false;
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let mut implied_by = None;
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for meta in metas {
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let Some(mi) = meta.meta_item() else {
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handle_errors(
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&sess.parse_sess,
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meta.span(),
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AttrError::UnsupportedLiteral(UnsupportedLiteralReason::Generic, false),
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);
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continue 'outer;
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};
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match mi.name_or_empty() {
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sym::feature => {
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if !get(mi, &mut feature) {
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continue 'outer;
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}
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}
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sym::reason => {
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if !get(mi, &mut reason) {
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continue 'outer;
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}
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}
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sym::issue => {
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if !get(mi, &mut issue) {
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continue 'outer;
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}
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// These unwraps are safe because `get` ensures the meta item
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// is a name/value pair string literal.
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issue_num = match issue.unwrap().as_str() {
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"none" => None,
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issue => match issue.parse::<NonZeroU32>() {
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Ok(num) => Some(num),
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Err(err) => {
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sess.emit_err(
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session_diagnostics::InvalidIssueString {
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span: mi.span,
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cause: session_diagnostics::InvalidIssueStringCause::from_int_error_kind(
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mi.name_value_literal_span().unwrap(),
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err.kind(),
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),
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},
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);
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continue 'outer;
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}
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},
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};
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}
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sym::soft => {
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if !mi.is_word() {
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sess.emit_err(session_diagnostics::SoftNoArgs {
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span: mi.span,
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});
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}
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is_soft = true;
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}
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sym::implied_by => {
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if !get(mi, &mut implied_by) {
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continue 'outer;
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}
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}
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_ => {
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handle_errors(
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&sess.parse_sess,
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meta.span(),
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AttrError::UnknownMetaItem(
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pprust::path_to_string(&mi.path),
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&["feature", "reason", "issue", "soft"],
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),
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);
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continue 'outer;
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}
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}
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}
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match (feature, reason, issue) {
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(Some(feature), reason, Some(_)) => {
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if !rustc_lexer::is_ident(feature.as_str()) {
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handle_errors(
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&sess.parse_sess,
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attr.span,
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AttrError::NonIdentFeature,
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);
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continue;
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}
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let level = Unstable {
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reason: UnstableReason::from_opt_reason(reason),
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issue: issue_num,
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is_soft,
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implied_by,
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};
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if sym::unstable == meta_name {
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stab = Some((Stability { level, feature }, attr.span));
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} else if sym::rustc_const_unstable == meta_name {
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const_stab = Some((
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ConstStability { level, feature, promotable: false },
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attr.span,
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));
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} else if sym::rustc_default_body_unstable == meta_name {
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body_stab =
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Some((DefaultBodyStability { level, feature }, attr.span));
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} else {
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unreachable!("Unknown stability attribute {meta_name}");
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}
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}
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(None, _, _) => {
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handle_errors(&sess.parse_sess, attr.span, AttrError::MissingFeature);
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continue;
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}
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_ => {
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sess.emit_err(session_diagnostics::MissingIssue { span: attr.span });
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continue;
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}
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}
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}
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sym::rustc_const_stable | sym::stable => {
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if meta_name == sym::stable && stab.is_some() {
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handle_errors(
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&sess.parse_sess,
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attr.span,
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AttrError::MultipleStabilityLevels,
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);
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break;
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} else if meta_name == sym::rustc_const_stable && const_stab.is_some() {
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handle_errors(
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&sess.parse_sess,
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attr.span,
|
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AttrError::MultipleStabilityLevels,
|
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);
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break;
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}
|
|
|
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let mut feature = None;
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let mut since = None;
|
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for meta in metas {
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match meta {
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NestedMetaItem::MetaItem(mi) => match mi.name_or_empty() {
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sym::feature => {
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if !get(mi, &mut feature) {
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continue 'outer;
|
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}
|
|
}
|
|
sym::since => {
|
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if !get(mi, &mut since) {
|
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continue 'outer;
|
|
}
|
|
}
|
|
_ => {
|
|
handle_errors(
|
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&sess.parse_sess,
|
|
meta.span(),
|
|
AttrError::UnknownMetaItem(
|
|
pprust::path_to_string(&mi.path),
|
|
&["feature", "since"],
|
|
),
|
|
);
|
|
continue 'outer;
|
|
}
|
|
},
|
|
NestedMetaItem::Literal(lit) => {
|
|
handle_errors(
|
|
&sess.parse_sess,
|
|
lit.span,
|
|
AttrError::UnsupportedLiteral(
|
|
UnsupportedLiteralReason::Generic,
|
|
false,
|
|
),
|
|
);
|
|
continue 'outer;
|
|
}
|
|
}
|
|
}
|
|
|
|
if let Some(s) = since && s.as_str() == VERSION_PLACEHOLDER {
|
|
since = Some(rust_version_symbol());
|
|
}
|
|
|
|
match (feature, since) {
|
|
(Some(feature), Some(since)) => {
|
|
let level = Stable { since, allowed_through_unstable_modules: false };
|
|
if sym::stable == meta_name {
|
|
stab = Some((Stability { level, feature }, attr.span));
|
|
} else {
|
|
const_stab = Some((
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ConstStability { level, feature, promotable: false },
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|
attr.span,
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));
|
|
}
|
|
}
|
|
(None, _) => {
|
|
handle_errors(&sess.parse_sess, attr.span, AttrError::MissingFeature);
|
|
continue;
|
|
}
|
|
_ => {
|
|
handle_errors(&sess.parse_sess, attr.span, AttrError::MissingSince);
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
_ => unreachable!(),
|
|
}
|
|
}
|
|
}
|
|
|
|
// Merge the const-unstable info into the stability info
|
|
if promotable {
|
|
if let Some((ref mut stab, _)) = const_stab {
|
|
stab.promotable = promotable;
|
|
} else {
|
|
sess.emit_err(session_diagnostics::RustcPromotablePairing { span: item_sp });
|
|
}
|
|
}
|
|
|
|
if allowed_through_unstable_modules {
|
|
if let Some((
|
|
Stability {
|
|
level: StabilityLevel::Stable { ref mut allowed_through_unstable_modules, .. },
|
|
..
|
|
},
|
|
_,
|
|
)) = stab
|
|
{
|
|
*allowed_through_unstable_modules = true;
|
|
} else {
|
|
sess.emit_err(session_diagnostics::RustcAllowedUnstablePairing { span: item_sp });
|
|
}
|
|
}
|
|
|
|
(stab, const_stab, body_stab)
|
|
}
|
|
|
|
pub fn find_crate_name(sess: &Session, attrs: &[Attribute]) -> Option<Symbol> {
|
|
sess.first_attr_value_str_by_name(attrs, sym::crate_name)
|
|
}
|
|
|
|
#[derive(Clone, Debug)]
|
|
pub struct Condition {
|
|
pub name: Symbol,
|
|
pub name_span: Span,
|
|
pub value: Option<Symbol>,
|
|
pub value_span: Option<Span>,
|
|
pub span: Span,
|
|
}
|
|
|
|
/// Tests if a cfg-pattern matches the cfg set
|
|
pub fn cfg_matches(
|
|
cfg: &ast::MetaItem,
|
|
sess: &ParseSess,
|
|
lint_node_id: NodeId,
|
|
features: Option<&Features>,
|
|
) -> bool {
|
|
eval_condition(cfg, sess, features, &mut |cfg| {
|
|
try_gate_cfg(cfg.name, cfg.span, sess, features);
|
|
if let Some(names_valid) = &sess.check_config.names_valid {
|
|
if !names_valid.contains(&cfg.name) {
|
|
sess.buffer_lint_with_diagnostic(
|
|
UNEXPECTED_CFGS,
|
|
cfg.span,
|
|
lint_node_id,
|
|
"unexpected `cfg` condition name",
|
|
BuiltinLintDiagnostics::UnexpectedCfg((cfg.name, cfg.name_span), None),
|
|
);
|
|
}
|
|
}
|
|
if let Some(value) = cfg.value {
|
|
if let Some(values) = &sess.check_config.values_valid.get(&cfg.name) {
|
|
if !values.contains(&value) {
|
|
sess.buffer_lint_with_diagnostic(
|
|
UNEXPECTED_CFGS,
|
|
cfg.span,
|
|
lint_node_id,
|
|
"unexpected `cfg` condition value",
|
|
BuiltinLintDiagnostics::UnexpectedCfg(
|
|
(cfg.name, cfg.name_span),
|
|
cfg.value_span.map(|vs| (value, vs)),
|
|
),
|
|
);
|
|
}
|
|
}
|
|
}
|
|
sess.config.contains(&(cfg.name, cfg.value))
|
|
})
|
|
}
|
|
|
|
fn try_gate_cfg(name: Symbol, span: Span, sess: &ParseSess, features: Option<&Features>) {
|
|
let gate = find_gated_cfg(|sym| sym == name);
|
|
if let (Some(feats), Some(gated_cfg)) = (features, gate) {
|
|
gate_cfg(&gated_cfg, span, sess, feats);
|
|
}
|
|
}
|
|
|
|
fn gate_cfg(gated_cfg: &GatedCfg, cfg_span: Span, sess: &ParseSess, features: &Features) {
|
|
let (cfg, feature, has_feature) = gated_cfg;
|
|
if !has_feature(features) && !cfg_span.allows_unstable(*feature) {
|
|
let explain = format!("`cfg({})` is experimental and subject to change", cfg);
|
|
feature_err(sess, *feature, cfg_span, &explain).emit();
|
|
}
|
|
}
|
|
|
|
#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
|
|
struct Version {
|
|
major: u16,
|
|
minor: u16,
|
|
patch: u16,
|
|
}
|
|
|
|
fn parse_version(s: &str, allow_appendix: bool) -> Option<Version> {
|
|
let mut components = s.split('-');
|
|
let d = components.next()?;
|
|
if !allow_appendix && components.next().is_some() {
|
|
return None;
|
|
}
|
|
let mut digits = d.splitn(3, '.');
|
|
let major = digits.next()?.parse().ok()?;
|
|
let minor = digits.next()?.parse().ok()?;
|
|
let patch = digits.next().unwrap_or("0").parse().ok()?;
|
|
Some(Version { major, minor, patch })
|
|
}
|
|
|
|
/// Evaluate a cfg-like condition (with `any` and `all`), using `eval` to
|
|
/// evaluate individual items.
|
|
pub fn eval_condition(
|
|
cfg: &ast::MetaItem,
|
|
sess: &ParseSess,
|
|
features: Option<&Features>,
|
|
eval: &mut impl FnMut(Condition) -> bool,
|
|
) -> bool {
|
|
match cfg.kind {
|
|
ast::MetaItemKind::List(ref mis) if cfg.name_or_empty() == sym::version => {
|
|
try_gate_cfg(sym::version, cfg.span, sess, features);
|
|
let (min_version, span) = match &mis[..] {
|
|
[NestedMetaItem::Literal(Lit { kind: LitKind::Str(sym, ..), span, .. })] => {
|
|
(sym, span)
|
|
}
|
|
[
|
|
NestedMetaItem::Literal(Lit { span, .. })
|
|
| NestedMetaItem::MetaItem(MetaItem { span, .. }),
|
|
] => {
|
|
sess.emit_err(session_diagnostics::ExpectedVersionLiteral { span: *span });
|
|
return false;
|
|
}
|
|
[..] => {
|
|
sess.emit_err(session_diagnostics::ExpectedSingleVersionLiteral {
|
|
span: cfg.span,
|
|
});
|
|
return false;
|
|
}
|
|
};
|
|
let Some(min_version) = parse_version(min_version.as_str(), false) else {
|
|
sess.emit_warning(session_diagnostics::UnknownVersionLiteral { span: *span });
|
|
return false;
|
|
};
|
|
let rustc_version = parse_version(env!("CFG_RELEASE"), true).unwrap();
|
|
|
|
// See https://github.com/rust-lang/rust/issues/64796#issuecomment-640851454 for details
|
|
if sess.assume_incomplete_release {
|
|
rustc_version > min_version
|
|
} else {
|
|
rustc_version >= min_version
|
|
}
|
|
}
|
|
ast::MetaItemKind::List(ref mis) => {
|
|
for mi in mis.iter() {
|
|
if !mi.is_meta_item() {
|
|
handle_errors(
|
|
sess,
|
|
mi.span(),
|
|
AttrError::UnsupportedLiteral(UnsupportedLiteralReason::Generic, false),
|
|
);
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// The unwraps below may look dangerous, but we've already asserted
|
|
// that they won't fail with the loop above.
|
|
match cfg.name_or_empty() {
|
|
sym::any => mis
|
|
.iter()
|
|
// We don't use any() here, because we want to evaluate all cfg condition
|
|
// as eval_condition can (and does) extra checks
|
|
.fold(false, |res, mi| {
|
|
res | eval_condition(mi.meta_item().unwrap(), sess, features, eval)
|
|
}),
|
|
sym::all => mis
|
|
.iter()
|
|
// We don't use all() here, because we want to evaluate all cfg condition
|
|
// as eval_condition can (and does) extra checks
|
|
.fold(true, |res, mi| {
|
|
res & eval_condition(mi.meta_item().unwrap(), sess, features, eval)
|
|
}),
|
|
sym::not => {
|
|
if mis.len() != 1 {
|
|
sess.emit_err(session_diagnostics::ExpectedOneCfgPattern {
|
|
span: cfg.span,
|
|
});
|
|
return false;
|
|
}
|
|
|
|
!eval_condition(mis[0].meta_item().unwrap(), sess, features, eval)
|
|
}
|
|
sym::target => {
|
|
if let Some(features) = features && !features.cfg_target_compact {
|
|
feature_err(
|
|
sess,
|
|
sym::cfg_target_compact,
|
|
cfg.span,
|
|
&"compact `cfg(target(..))` is experimental and subject to change"
|
|
).emit();
|
|
}
|
|
|
|
mis.iter().fold(true, |res, mi| {
|
|
let mut mi = mi.meta_item().unwrap().clone();
|
|
if let [seg, ..] = &mut mi.path.segments[..] {
|
|
seg.ident.name = Symbol::intern(&format!("target_{}", seg.ident.name));
|
|
}
|
|
|
|
res & eval_condition(&mi, sess, features, eval)
|
|
})
|
|
}
|
|
_ => {
|
|
sess.emit_err(session_diagnostics::InvalidPredicate {
|
|
span: cfg.span,
|
|
predicate: pprust::path_to_string(&cfg.path),
|
|
});
|
|
false
|
|
}
|
|
}
|
|
}
|
|
ast::MetaItemKind::Word | MetaItemKind::NameValue(..) if cfg.path.segments.len() != 1 => {
|
|
sess.emit_err(session_diagnostics::CfgPredicateIdentifier { span: cfg.path.span });
|
|
true
|
|
}
|
|
MetaItemKind::NameValue(ref lit) if !lit.kind.is_str() => {
|
|
handle_errors(
|
|
sess,
|
|
lit.span,
|
|
AttrError::UnsupportedLiteral(
|
|
UnsupportedLiteralReason::CfgString,
|
|
lit.kind.is_bytestr(),
|
|
),
|
|
);
|
|
true
|
|
}
|
|
ast::MetaItemKind::Word | ast::MetaItemKind::NameValue(..) => {
|
|
let ident = cfg.ident().expect("multi-segment cfg predicate");
|
|
eval(Condition {
|
|
name: ident.name,
|
|
name_span: ident.span,
|
|
value: cfg.value_str(),
|
|
value_span: cfg.name_value_literal_span(),
|
|
span: cfg.span,
|
|
})
|
|
}
|
|
}
|
|
}
|
|
|
|
#[derive(Copy, Debug, Encodable, Decodable, Clone, HashStable_Generic)]
|
|
pub struct Deprecation {
|
|
pub since: Option<Symbol>,
|
|
/// The note to issue a reason.
|
|
pub note: Option<Symbol>,
|
|
/// A text snippet used to completely replace any use of the deprecated item in an expression.
|
|
///
|
|
/// This is currently unstable.
|
|
pub suggestion: Option<Symbol>,
|
|
|
|
/// Whether to treat the since attribute as being a Rust version identifier
|
|
/// (rather than an opaque string).
|
|
pub is_since_rustc_version: bool,
|
|
}
|
|
|
|
/// Finds the deprecation attribute. `None` if none exists.
|
|
pub fn find_deprecation(sess: &Session, attrs: &[Attribute]) -> Option<(Deprecation, Span)> {
|
|
find_deprecation_generic(sess, attrs.iter())
|
|
}
|
|
|
|
fn find_deprecation_generic<'a, I>(sess: &Session, attrs_iter: I) -> Option<(Deprecation, Span)>
|
|
where
|
|
I: Iterator<Item = &'a Attribute>,
|
|
{
|
|
let mut depr: Option<(Deprecation, Span)> = None;
|
|
let is_rustc = sess.features_untracked().staged_api;
|
|
|
|
'outer: for attr in attrs_iter {
|
|
if !attr.has_name(sym::deprecated) {
|
|
continue;
|
|
}
|
|
|
|
let Some(meta) = attr.meta() else {
|
|
continue;
|
|
};
|
|
let mut since = None;
|
|
let mut note = None;
|
|
let mut suggestion = None;
|
|
match &meta.kind {
|
|
MetaItemKind::Word => {}
|
|
MetaItemKind::NameValue(..) => note = meta.value_str(),
|
|
MetaItemKind::List(list) => {
|
|
let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
|
|
if item.is_some() {
|
|
handle_errors(
|
|
&sess.parse_sess,
|
|
meta.span,
|
|
AttrError::MultipleItem(pprust::path_to_string(&meta.path)),
|
|
);
|
|
return false;
|
|
}
|
|
if let Some(v) = meta.value_str() {
|
|
*item = Some(v);
|
|
true
|
|
} else {
|
|
if let Some(lit) = meta.name_value_literal() {
|
|
handle_errors(
|
|
&sess.parse_sess,
|
|
lit.span,
|
|
AttrError::UnsupportedLiteral(
|
|
UnsupportedLiteralReason::DeprecatedString,
|
|
lit.kind.is_bytestr(),
|
|
),
|
|
);
|
|
} else {
|
|
sess.emit_err(session_diagnostics::IncorrectMetaItem2 {
|
|
span: meta.span,
|
|
});
|
|
}
|
|
|
|
false
|
|
}
|
|
};
|
|
|
|
for meta in list {
|
|
match meta {
|
|
NestedMetaItem::MetaItem(mi) => match mi.name_or_empty() {
|
|
sym::since => {
|
|
if !get(mi, &mut since) {
|
|
continue 'outer;
|
|
}
|
|
}
|
|
sym::note => {
|
|
if !get(mi, &mut note) {
|
|
continue 'outer;
|
|
}
|
|
}
|
|
sym::suggestion => {
|
|
if !sess.features_untracked().deprecated_suggestion {
|
|
sess.emit_err(session_diagnostics::DeprecatedItemSuggestion {
|
|
span: mi.span,
|
|
is_nightly: sess.is_nightly_build().then_some(()),
|
|
details: (),
|
|
});
|
|
}
|
|
|
|
if !get(mi, &mut suggestion) {
|
|
continue 'outer;
|
|
}
|
|
}
|
|
_ => {
|
|
handle_errors(
|
|
&sess.parse_sess,
|
|
meta.span(),
|
|
AttrError::UnknownMetaItem(
|
|
pprust::path_to_string(&mi.path),
|
|
if sess.features_untracked().deprecated_suggestion {
|
|
&["since", "note", "suggestion"]
|
|
} else {
|
|
&["since", "note"]
|
|
},
|
|
),
|
|
);
|
|
continue 'outer;
|
|
}
|
|
},
|
|
NestedMetaItem::Literal(lit) => {
|
|
handle_errors(
|
|
&sess.parse_sess,
|
|
lit.span,
|
|
AttrError::UnsupportedLiteral(
|
|
UnsupportedLiteralReason::DeprecatedKvPair,
|
|
false,
|
|
),
|
|
);
|
|
continue 'outer;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if is_rustc {
|
|
if since.is_none() {
|
|
handle_errors(&sess.parse_sess, attr.span, AttrError::MissingSince);
|
|
continue;
|
|
}
|
|
|
|
if note.is_none() {
|
|
sess.emit_err(session_diagnostics::MissingNote { span: attr.span });
|
|
continue;
|
|
}
|
|
}
|
|
|
|
depr = Some((
|
|
Deprecation { since, note, suggestion, is_since_rustc_version: is_rustc },
|
|
attr.span,
|
|
));
|
|
}
|
|
|
|
depr
|
|
}
|
|
|
|
#[derive(PartialEq, Debug, Encodable, Decodable, Copy, Clone)]
|
|
pub enum ReprAttr {
|
|
ReprInt(IntType),
|
|
ReprC,
|
|
ReprPacked(u32),
|
|
ReprSimd,
|
|
ReprTransparent,
|
|
ReprAlign(u32),
|
|
}
|
|
|
|
#[derive(Eq, PartialEq, Debug, Copy, Clone)]
|
|
#[derive(Encodable, Decodable, HashStable_Generic)]
|
|
pub enum IntType {
|
|
SignedInt(ast::IntTy),
|
|
UnsignedInt(ast::UintTy),
|
|
}
|
|
|
|
impl IntType {
|
|
#[inline]
|
|
pub fn is_signed(self) -> bool {
|
|
use IntType::*;
|
|
|
|
match self {
|
|
SignedInt(..) => true,
|
|
UnsignedInt(..) => false,
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Parse #[repr(...)] forms.
|
|
///
|
|
/// Valid repr contents: any of the primitive integral type names (see
|
|
/// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
|
|
/// the same discriminant size that the corresponding C enum would or C
|
|
/// structure layout, `packed` to remove padding, and `transparent` to delegate representation
|
|
/// concerns to the only non-ZST field.
|
|
pub fn find_repr_attrs(sess: &Session, attr: &Attribute) -> Vec<ReprAttr> {
|
|
if attr.has_name(sym::repr) { parse_repr_attr(sess, attr) } else { Vec::new() }
|
|
}
|
|
|
|
pub fn parse_repr_attr(sess: &Session, attr: &Attribute) -> Vec<ReprAttr> {
|
|
assert!(attr.has_name(sym::repr), "expected `#[repr(..)]`, found: {:?}", attr);
|
|
use ReprAttr::*;
|
|
let mut acc = Vec::new();
|
|
let diagnostic = &sess.parse_sess.span_diagnostic;
|
|
|
|
if let Some(items) = attr.meta_item_list() {
|
|
for item in items {
|
|
let mut recognised = false;
|
|
if item.is_word() {
|
|
let hint = match item.name_or_empty() {
|
|
sym::C => Some(ReprC),
|
|
sym::packed => Some(ReprPacked(1)),
|
|
sym::simd => Some(ReprSimd),
|
|
sym::transparent => Some(ReprTransparent),
|
|
sym::align => {
|
|
sess.emit_err(session_diagnostics::InvalidReprAlignNeedArg {
|
|
span: item.span(),
|
|
});
|
|
recognised = true;
|
|
None
|
|
}
|
|
name => int_type_of_word(name).map(ReprInt),
|
|
};
|
|
|
|
if let Some(h) = hint {
|
|
recognised = true;
|
|
acc.push(h);
|
|
}
|
|
} else if let Some((name, value)) = item.name_value_literal() {
|
|
let mut literal_error = None;
|
|
if name == sym::align {
|
|
recognised = true;
|
|
match parse_alignment(&value.kind) {
|
|
Ok(literal) => acc.push(ReprAlign(literal)),
|
|
Err(message) => literal_error = Some(message),
|
|
};
|
|
} else if name == sym::packed {
|
|
recognised = true;
|
|
match parse_alignment(&value.kind) {
|
|
Ok(literal) => acc.push(ReprPacked(literal)),
|
|
Err(message) => literal_error = Some(message),
|
|
};
|
|
} else if matches!(name, sym::C | sym::simd | sym::transparent)
|
|
|| int_type_of_word(name).is_some()
|
|
{
|
|
recognised = true;
|
|
sess.emit_err(session_diagnostics::InvalidReprHintNoParen {
|
|
span: item.span(),
|
|
name: name.to_ident_string(),
|
|
});
|
|
}
|
|
if let Some(literal_error) = literal_error {
|
|
sess.emit_err(session_diagnostics::InvalidReprGeneric {
|
|
span: item.span(),
|
|
repr_arg: name.to_ident_string(),
|
|
error_part: literal_error,
|
|
});
|
|
}
|
|
} else if let Some(meta_item) = item.meta_item() {
|
|
if let MetaItemKind::NameValue(ref value) = meta_item.kind {
|
|
if meta_item.has_name(sym::align) || meta_item.has_name(sym::packed) {
|
|
let name = meta_item.name_or_empty().to_ident_string();
|
|
recognised = true;
|
|
sess.emit_err(session_diagnostics::IncorrectReprFormatGeneric {
|
|
span: item.span(),
|
|
repr_arg: &name,
|
|
cause: IncorrectReprFormatGenericCause::from_lit_kind(
|
|
item.span(),
|
|
&value.kind,
|
|
&name,
|
|
),
|
|
});
|
|
} else if matches!(
|
|
meta_item.name_or_empty(),
|
|
sym::C | sym::simd | sym::transparent
|
|
) || int_type_of_word(meta_item.name_or_empty()).is_some()
|
|
{
|
|
recognised = true;
|
|
sess.emit_err(session_diagnostics::InvalidReprHintNoValue {
|
|
span: meta_item.span,
|
|
name: meta_item.name_or_empty().to_ident_string(),
|
|
});
|
|
}
|
|
} else if let MetaItemKind::List(_) = meta_item.kind {
|
|
if meta_item.has_name(sym::align) {
|
|
recognised = true;
|
|
sess.emit_err(session_diagnostics::IncorrectReprFormatAlignOneArg {
|
|
span: meta_item.span,
|
|
});
|
|
} else if meta_item.has_name(sym::packed) {
|
|
recognised = true;
|
|
sess.emit_err(session_diagnostics::IncorrectReprFormatPackedOneOrZeroArg {
|
|
span: meta_item.span,
|
|
});
|
|
} else if matches!(
|
|
meta_item.name_or_empty(),
|
|
sym::C | sym::simd | sym::transparent
|
|
) || int_type_of_word(meta_item.name_or_empty()).is_some()
|
|
{
|
|
recognised = true;
|
|
sess.emit_err(session_diagnostics::InvalidReprHintNoParen {
|
|
span: meta_item.span,
|
|
name: meta_item.name_or_empty().to_ident_string(),
|
|
});
|
|
}
|
|
}
|
|
}
|
|
if !recognised {
|
|
// Not a word we recognize. This will be caught and reported by
|
|
// the `check_mod_attrs` pass, but this pass doesn't always run
|
|
// (e.g. if we only pretty-print the source), so we have to gate
|
|
// the `delay_span_bug` call as follows:
|
|
if sess.opts.pretty.map_or(true, |pp| pp.needs_analysis()) {
|
|
diagnostic.delay_span_bug(item.span(), "unrecognized representation hint");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
acc
|
|
}
|
|
|
|
fn int_type_of_word(s: Symbol) -> Option<IntType> {
|
|
use IntType::*;
|
|
|
|
match s {
|
|
sym::i8 => Some(SignedInt(ast::IntTy::I8)),
|
|
sym::u8 => Some(UnsignedInt(ast::UintTy::U8)),
|
|
sym::i16 => Some(SignedInt(ast::IntTy::I16)),
|
|
sym::u16 => Some(UnsignedInt(ast::UintTy::U16)),
|
|
sym::i32 => Some(SignedInt(ast::IntTy::I32)),
|
|
sym::u32 => Some(UnsignedInt(ast::UintTy::U32)),
|
|
sym::i64 => Some(SignedInt(ast::IntTy::I64)),
|
|
sym::u64 => Some(UnsignedInt(ast::UintTy::U64)),
|
|
sym::i128 => Some(SignedInt(ast::IntTy::I128)),
|
|
sym::u128 => Some(UnsignedInt(ast::UintTy::U128)),
|
|
sym::isize => Some(SignedInt(ast::IntTy::Isize)),
|
|
sym::usize => Some(UnsignedInt(ast::UintTy::Usize)),
|
|
_ => None,
|
|
}
|
|
}
|
|
|
|
pub enum TransparencyError {
|
|
UnknownTransparency(Symbol, Span),
|
|
MultipleTransparencyAttrs(Span, Span),
|
|
}
|
|
|
|
pub fn find_transparency(
|
|
attrs: &[Attribute],
|
|
macro_rules: bool,
|
|
) -> (Transparency, Option<TransparencyError>) {
|
|
let mut transparency = None;
|
|
let mut error = None;
|
|
for attr in attrs {
|
|
if attr.has_name(sym::rustc_macro_transparency) {
|
|
if let Some((_, old_span)) = transparency {
|
|
error = Some(TransparencyError::MultipleTransparencyAttrs(old_span, attr.span));
|
|
break;
|
|
} else if let Some(value) = attr.value_str() {
|
|
transparency = Some((
|
|
match value {
|
|
sym::transparent => Transparency::Transparent,
|
|
sym::semitransparent => Transparency::SemiTransparent,
|
|
sym::opaque => Transparency::Opaque,
|
|
_ => {
|
|
error = Some(TransparencyError::UnknownTransparency(value, attr.span));
|
|
continue;
|
|
}
|
|
},
|
|
attr.span,
|
|
));
|
|
}
|
|
}
|
|
}
|
|
let fallback = if macro_rules { Transparency::SemiTransparent } else { Transparency::Opaque };
|
|
(transparency.map_or(fallback, |t| t.0), error)
|
|
}
|
|
|
|
pub fn allow_internal_unstable<'a>(
|
|
sess: &'a Session,
|
|
attrs: &'a [Attribute],
|
|
) -> impl Iterator<Item = Symbol> + 'a {
|
|
allow_unstable(sess, attrs, sym::allow_internal_unstable)
|
|
}
|
|
|
|
pub fn rustc_allow_const_fn_unstable<'a>(
|
|
sess: &'a Session,
|
|
attrs: &'a [Attribute],
|
|
) -> impl Iterator<Item = Symbol> + 'a {
|
|
allow_unstable(sess, attrs, sym::rustc_allow_const_fn_unstable)
|
|
}
|
|
|
|
fn allow_unstable<'a>(
|
|
sess: &'a Session,
|
|
attrs: &'a [Attribute],
|
|
symbol: Symbol,
|
|
) -> impl Iterator<Item = Symbol> + 'a {
|
|
let attrs = sess.filter_by_name(attrs, symbol);
|
|
let list = attrs
|
|
.filter_map(move |attr| {
|
|
attr.meta_item_list().or_else(|| {
|
|
sess.emit_err(session_diagnostics::ExpectsFeatureList {
|
|
span: attr.span,
|
|
name: symbol.to_ident_string(),
|
|
});
|
|
None
|
|
})
|
|
})
|
|
.flatten();
|
|
|
|
list.into_iter().filter_map(move |it| {
|
|
let name = it.ident().map(|ident| ident.name);
|
|
if name.is_none() {
|
|
sess.emit_err(session_diagnostics::ExpectsFeatures {
|
|
span: it.span(),
|
|
name: symbol.to_ident_string(),
|
|
});
|
|
}
|
|
name
|
|
})
|
|
}
|
|
|
|
pub fn parse_alignment(node: &ast::LitKind) -> Result<u32, &'static str> {
|
|
if let ast::LitKind::Int(literal, ast::LitIntType::Unsuffixed) = node {
|
|
if literal.is_power_of_two() {
|
|
// rustc_middle::ty::layout::Align restricts align to <= 2^29
|
|
if *literal <= 1 << 29 { Ok(*literal as u32) } else { Err("larger than 2^29") }
|
|
} else {
|
|
Err("not a power of two")
|
|
}
|
|
} else {
|
|
Err("not an unsuffixed integer")
|
|
}
|
|
}
|