diff options
Diffstat (limited to 'compiler/rustc_attr_parsing/src/context.rs')
| -rw-r--r-- | compiler/rustc_attr_parsing/src/context.rs | 592 |
1 files changed, 17 insertions, 575 deletions
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs index c0d3bc99ba9..d79177076c7 100644 --- a/compiler/rustc_attr_parsing/src/context.rs +++ b/compiler/rustc_attr_parsing/src/context.rs @@ -3,19 +3,17 @@ use std::collections::BTreeMap; use std::ops::{Deref, DerefMut}; use std::sync::LazyLock; -use itertools::Itertools; use private::Sealed; -use rustc_ast::{self as ast, AttrStyle, LitKind, MetaItemLit, NodeId}; -use rustc_errors::{DiagCtxtHandle, Diagnostic}; -use rustc_feature::{AttributeTemplate, Features}; +use rustc_ast::{AttrStyle, MetaItemLit, NodeId}; +use rustc_errors::Diagnostic; +use rustc_feature::AttributeTemplate; use rustc_hir::attrs::AttributeKind; use rustc_hir::lints::{AttributeLint, AttributeLintKind}; -use rustc_hir::{ - AttrArgs, AttrItem, AttrPath, Attribute, HashIgnoredAttrId, HirId, MethodKind, Target, -}; +use rustc_hir::{AttrPath, HirId}; use rustc_session::Session; -use rustc_span::{DUMMY_SP, ErrorGuaranteed, Span, Symbol, sym}; +use rustc_span::{ErrorGuaranteed, Span, Symbol}; +use crate::AttributeParser; use crate::attributes::allow_unstable::{ AllowConstFnUnstableParser, AllowInternalUnstableParser, UnstableFeatureBoundParser, }; @@ -65,23 +63,21 @@ use crate::attributes::traits::{ }; use crate::attributes::transparency::TransparencyParser; use crate::attributes::{AttributeParser as _, Combine, Single, WithoutArgs}; -use crate::context::MaybeWarn::{Allow, Error, Warn}; -use crate::parser::{ArgParser, MetaItemParser, PathParser}; -use crate::session_diagnostics::{ - AttributeParseError, AttributeParseErrorReason, InvalidTarget, UnknownMetaItem, -}; +use crate::parser::{ArgParser, PathParser}; +use crate::session_diagnostics::{AttributeParseError, AttributeParseErrorReason, UnknownMetaItem}; +use crate::target_checking::AllowedTargets; type GroupType<S> = LazyLock<GroupTypeInner<S>>; -struct GroupTypeInner<S: Stage> { - accepters: BTreeMap<&'static [Symbol], Vec<GroupTypeInnerAccept<S>>>, - finalizers: Vec<FinalizeFn<S>>, +pub(super) struct GroupTypeInner<S: Stage> { + pub(super) accepters: BTreeMap<&'static [Symbol], Vec<GroupTypeInnerAccept<S>>>, + pub(super) finalizers: Vec<FinalizeFn<S>>, } -struct GroupTypeInnerAccept<S: Stage> { - template: AttributeTemplate, - accept_fn: AcceptFn<S>, - allowed_targets: AllowedTargets, +pub(super) struct GroupTypeInnerAccept<S: Stage> { + pub(super) template: AttributeTemplate, + pub(super) accept_fn: AcceptFn<S>, + pub(super) allowed_targets: AllowedTargets, } type AcceptFn<S> = @@ -595,7 +591,7 @@ pub struct SharedContext<'p, 'sess, S: Stage> { /// The id ([`NodeId`] if `S` is `Early`, [`HirId`] if `S` is `Late`) of the syntactical component this attribute was applied to pub(crate) target_id: S::Id, - emit_lint: &'p mut dyn FnMut(AttributeLint<S::Id>), + pub(crate) emit_lint: &'p mut dyn FnMut(AttributeLint<S::Id>), } /// Context given to every attribute parser during finalization. @@ -666,557 +662,3 @@ impl ShouldEmit { } } } - -#[derive(Debug)] -pub(crate) enum AllowedTargets { - AllowList(&'static [MaybeWarn]), - AllowListWarnRest(&'static [MaybeWarn]), -} - -pub(crate) enum AllowedResult { - Allowed, - Warn, - Error, -} - -impl AllowedTargets { - pub(crate) fn is_allowed(&self, target: Target) -> AllowedResult { - match self { - AllowedTargets::AllowList(list) => { - if list.contains(&Allow(target)) { - AllowedResult::Allowed - } else if list.contains(&Warn(target)) { - AllowedResult::Warn - } else { - AllowedResult::Error - } - } - AllowedTargets::AllowListWarnRest(list) => { - if list.contains(&Allow(target)) { - AllowedResult::Allowed - } else if list.contains(&Error(target)) { - AllowedResult::Error - } else { - AllowedResult::Warn - } - } - } - } - - pub(crate) fn allowed_targets(&self) -> Vec<Target> { - match self { - AllowedTargets::AllowList(list) => list, - AllowedTargets::AllowListWarnRest(list) => list, - } - .iter() - .filter_map(|target| match target { - Allow(target) => Some(*target), - Warn(_) => None, - Error(_) => None, - }) - .collect() - } -} - -#[derive(Debug, Eq, PartialEq)] -pub(crate) enum MaybeWarn { - Allow(Target), - Warn(Target), - Error(Target), -} - -/// Context created once, for example as part of the ast lowering -/// context, through which all attributes can be lowered. -pub struct AttributeParser<'sess, S: Stage = Late> { - pub(crate) tools: Vec<Symbol>, - features: Option<&'sess Features>, - sess: &'sess Session, - stage: S, - - /// *Only* parse attributes with this symbol. - /// - /// Used in cases where we want the lowering infrastructure for parse just a single attribute. - parse_only: Option<Symbol>, -} - -impl<'sess> AttributeParser<'sess, Early> { - /// This method allows you to parse attributes *before* you have access to features or tools. - /// One example where this is necessary, is to parse `feature` attributes themselves for - /// example. - /// - /// Try to use this as little as possible. Attributes *should* be lowered during - /// `rustc_ast_lowering`. Some attributes require access to features to parse, which would - /// crash if you tried to do so through [`parse_limited`](Self::parse_limited). - /// - /// To make sure use is limited, supply a `Symbol` you'd like to parse. Only attributes with - /// that symbol are picked out of the list of instructions and parsed. Those are returned. - /// - /// No diagnostics will be emitted when parsing limited. Lints are not emitted at all, while - /// errors will be emitted as a delayed bugs. in other words, we *expect* attributes parsed - /// with `parse_limited` to be reparsed later during ast lowering where we *do* emit the errors - pub fn parse_limited( - sess: &'sess Session, - attrs: &[ast::Attribute], - sym: Symbol, - target_span: Span, - target_node_id: NodeId, - features: Option<&'sess Features>, - ) -> Option<Attribute> { - let mut p = Self { - features, - tools: Vec::new(), - parse_only: Some(sym), - sess, - stage: Early { emit_errors: ShouldEmit::Nothing }, - }; - let mut parsed = p.parse_attribute_list( - attrs, - target_span, - target_node_id, - Target::Crate, // Does not matter, we're not going to emit errors anyways - OmitDoc::Skip, - std::convert::identity, - |_lint| { - panic!("can't emit lints here for now (nothing uses this atm)"); - }, - ); - assert!(parsed.len() <= 1); - - parsed.pop() - } - - pub fn parse_single<T>( - sess: &'sess Session, - attr: &ast::Attribute, - target_span: Span, - target_node_id: NodeId, - features: Option<&'sess Features>, - emit_errors: ShouldEmit, - parse_fn: fn(cx: &mut AcceptContext<'_, '_, Early>, item: &ArgParser<'_>) -> T, - template: &AttributeTemplate, - ) -> T { - let mut parser = Self { - features, - tools: Vec::new(), - parse_only: None, - sess, - stage: Early { emit_errors }, - }; - let ast::AttrKind::Normal(normal_attr) = &attr.kind else { - panic!("parse_single called on a doc attr") - }; - let meta_parser = MetaItemParser::from_attr(normal_attr, parser.dcx()); - let path = meta_parser.path(); - let args = meta_parser.args(); - let mut cx: AcceptContext<'_, 'sess, Early> = AcceptContext { - shared: SharedContext { - cx: &mut parser, - target_span, - target_id: target_node_id, - emit_lint: &mut |_lint| { - panic!("can't emit lints here for now (nothing uses this atm)"); - }, - }, - attr_span: attr.span, - attr_style: attr.style, - template, - attr_path: path.get_attribute_path(), - }; - parse_fn(&mut cx, args) - } -} - -impl<'sess, S: Stage> AttributeParser<'sess, S> { - pub fn new( - sess: &'sess Session, - features: &'sess Features, - tools: Vec<Symbol>, - stage: S, - ) -> Self { - Self { features: Some(features), tools, parse_only: None, sess, stage } - } - - pub(crate) fn sess(&self) -> &'sess Session { - &self.sess - } - - pub(crate) fn features(&self) -> &'sess Features { - self.features.expect("features not available at this point in the compiler") - } - - pub(crate) fn features_option(&self) -> Option<&'sess Features> { - self.features - } - - pub(crate) fn dcx(&self) -> DiagCtxtHandle<'sess> { - self.sess().dcx() - } - - /// Parse a list of attributes. - /// - /// `target_span` is the span of the thing this list of attributes is applied to, - /// and when `omit_doc` is set, doc attributes are filtered out. - pub fn parse_attribute_list( - &mut self, - attrs: &[ast::Attribute], - target_span: Span, - target_id: S::Id, - target: Target, - omit_doc: OmitDoc, - - lower_span: impl Copy + Fn(Span) -> Span, - mut emit_lint: impl FnMut(AttributeLint<S::Id>), - ) -> Vec<Attribute> { - let mut attributes = Vec::new(); - let mut attr_paths = Vec::new(); - - for attr in attrs { - // If we're only looking for a single attribute, skip all the ones we don't care about. - if let Some(expected) = self.parse_only { - if !attr.has_name(expected) { - continue; - } - } - - // Sometimes, for example for `#![doc = include_str!("readme.md")]`, - // doc still contains a non-literal. You might say, when we're lowering attributes - // that's expanded right? But no, sometimes, when parsing attributes on macros, - // we already use the lowering logic and these are still there. So, when `omit_doc` - // is set we *also* want to ignore these. - if omit_doc == OmitDoc::Skip && attr.has_name(sym::doc) { - continue; - } - - match &attr.kind { - ast::AttrKind::DocComment(comment_kind, symbol) => { - if omit_doc == OmitDoc::Skip { - continue; - } - - attributes.push(Attribute::Parsed(AttributeKind::DocComment { - style: attr.style, - kind: *comment_kind, - span: lower_span(attr.span), - comment: *symbol, - })) - } - // // FIXME: make doc attributes go through a proper attribute parser - // ast::AttrKind::Normal(n) if n.has_name(sym::doc) => { - // let p = GenericMetaItemParser::from_attr(&n, self.dcx()); - // - // attributes.push(Attribute::Parsed(AttributeKind::DocComment { - // style: attr.style, - // kind: CommentKind::Line, - // span: attr.span, - // comment: p.args().name_value(), - // })) - // } - ast::AttrKind::Normal(n) => { - attr_paths.push(PathParser::Ast(&n.item.path)); - - let parser = MetaItemParser::from_attr(n, self.dcx()); - let path = parser.path(); - let args = parser.args(); - let parts = path.segments().map(|i| i.name).collect::<Vec<_>>(); - - if let Some(accepts) = S::parsers().accepters.get(parts.as_slice()) { - for accept in accepts { - let mut cx: AcceptContext<'_, 'sess, S> = AcceptContext { - shared: SharedContext { - cx: self, - target_span, - target_id, - emit_lint: &mut emit_lint, - }, - attr_span: lower_span(attr.span), - attr_style: attr.style, - template: &accept.template, - attr_path: path.get_attribute_path(), - }; - - (accept.accept_fn)(&mut cx, args); - - if self.stage.should_emit().should_emit() { - match accept.allowed_targets.is_allowed(target) { - AllowedResult::Allowed => {} - AllowedResult::Warn => { - let allowed_targets = - accept.allowed_targets.allowed_targets(); - let (applied, only) = allowed_targets_applied( - allowed_targets, - target, - self.features, - ); - emit_lint(AttributeLint { - id: target_id, - span: attr.span, - kind: AttributeLintKind::InvalidTarget { - name: parts[0], - target, - only: if only { "only " } else { "" }, - applied, - }, - }); - } - AllowedResult::Error => { - let allowed_targets = - accept.allowed_targets.allowed_targets(); - let (applied, only) = allowed_targets_applied( - allowed_targets, - target, - self.features, - ); - self.dcx().emit_err(InvalidTarget { - span: attr.span, - name: parts[0], - target: target.plural_name(), - only: if only { "only " } else { "" }, - applied, - }); - } - } - } - } - } else { - // If we're here, we must be compiling a tool attribute... Or someone - // forgot to parse their fancy new attribute. Let's warn them in any case. - // If you are that person, and you really think your attribute should - // remain unparsed, carefully read the documentation in this module and if - // you still think so you can add an exception to this assertion. - - // FIXME(jdonszelmann): convert other attributes, and check with this that - // we caught em all - // const FIXME_TEMPORARY_ATTR_ALLOWLIST: &[Symbol] = &[sym::cfg]; - // assert!( - // self.tools.contains(&parts[0]) || true, - // // || FIXME_TEMPORARY_ATTR_ALLOWLIST.contains(&parts[0]), - // "attribute {path} wasn't parsed and isn't a know tool attribute", - // ); - - attributes.push(Attribute::Unparsed(Box::new(AttrItem { - path: AttrPath::from_ast(&n.item.path), - args: self.lower_attr_args(&n.item.args, lower_span), - id: HashIgnoredAttrId { attr_id: attr.id }, - style: attr.style, - span: lower_span(attr.span), - }))); - } - } - } - } - - let mut parsed_attributes = Vec::new(); - for f in &S::parsers().finalizers { - if let Some(attr) = f(&mut FinalizeContext { - shared: SharedContext { - cx: self, - target_span, - target_id, - emit_lint: &mut emit_lint, - }, - all_attrs: &attr_paths, - }) { - parsed_attributes.push(Attribute::Parsed(attr)); - } - } - - attributes.extend(parsed_attributes); - - attributes - } - - /// Returns whether there is a parser for an attribute with this name - pub fn is_parsed_attribute(path: &[Symbol]) -> bool { - Late::parsers().accepters.contains_key(path) - } - - fn lower_attr_args(&self, args: &ast::AttrArgs, lower_span: impl Fn(Span) -> Span) -> AttrArgs { - match args { - ast::AttrArgs::Empty => AttrArgs::Empty, - ast::AttrArgs::Delimited(args) => AttrArgs::Delimited(args.clone()), - // This is an inert key-value attribute - it will never be visible to macros - // after it gets lowered to HIR. Therefore, we can extract literals to handle - // nonterminals in `#[doc]` (e.g. `#[doc = $e]`). - ast::AttrArgs::Eq { eq_span, expr } => { - // In valid code the value always ends up as a single literal. Otherwise, a dummy - // literal suffices because the error is handled elsewhere. - let lit = if let ast::ExprKind::Lit(token_lit) = expr.kind - && let Ok(lit) = - ast::MetaItemLit::from_token_lit(token_lit, lower_span(expr.span)) - { - lit - } else { - let guar = self.dcx().span_delayed_bug( - args.span().unwrap_or(DUMMY_SP), - "expr in place where literal is expected (builtin attr parsing)", - ); - ast::MetaItemLit { - symbol: sym::dummy, - suffix: None, - kind: ast::LitKind::Err(guar), - span: DUMMY_SP, - } - }; - AttrArgs::Eq { eq_span: lower_span(*eq_span), expr: lit } - } - } - } -} - -/// Takes a list of `allowed_targets` for an attribute, and the `target` the attribute was applied to. -/// Does some heuristic-based filtering to remove uninteresting targets, and formats the targets into a string -pub(crate) fn allowed_targets_applied( - mut allowed_targets: Vec<Target>, - target: Target, - features: Option<&Features>, -) -> (String, bool) { - // Remove unstable targets from `allowed_targets` if their features are not enabled - if let Some(features) = features { - if !features.fn_delegation() { - allowed_targets.retain(|t| !matches!(t, Target::Delegation { .. })); - } - if !features.stmt_expr_attributes() { - allowed_targets.retain(|t| !matches!(t, Target::Expression | Target::Statement)); - } - if !features.extern_types() { - allowed_targets.retain(|t| !matches!(t, Target::ForeignTy)); - } - } - - // We define groups of "similar" targets. - // If at least two of the targets are allowed, and the `target` is not in the group, - // we collapse the entire group to a single entry to simplify the target list - const FUNCTION_LIKE: &[Target] = &[ - Target::Fn, - Target::Closure, - Target::ForeignFn, - Target::Method(MethodKind::Inherent), - Target::Method(MethodKind::Trait { body: false }), - Target::Method(MethodKind::Trait { body: true }), - Target::Method(MethodKind::TraitImpl), - ]; - const METHOD_LIKE: &[Target] = &[ - Target::Method(MethodKind::Inherent), - Target::Method(MethodKind::Trait { body: false }), - Target::Method(MethodKind::Trait { body: true }), - Target::Method(MethodKind::TraitImpl), - ]; - const IMPL_LIKE: &[Target] = - &[Target::Impl { of_trait: false }, Target::Impl { of_trait: true }]; - const ADT_LIKE: &[Target] = &[Target::Struct, Target::Enum]; - - let mut added_fake_targets = Vec::new(); - filter_targets( - &mut allowed_targets, - FUNCTION_LIKE, - "functions", - target, - &mut added_fake_targets, - ); - filter_targets(&mut allowed_targets, METHOD_LIKE, "methods", target, &mut added_fake_targets); - filter_targets(&mut allowed_targets, IMPL_LIKE, "impl blocks", target, &mut added_fake_targets); - filter_targets(&mut allowed_targets, ADT_LIKE, "data types", target, &mut added_fake_targets); - - // If there is now only 1 target left, show that as the only possible target - ( - added_fake_targets - .iter() - .copied() - .chain(allowed_targets.iter().map(|t| t.plural_name())) - .join(", "), - allowed_targets.len() + added_fake_targets.len() == 1, - ) -} - -fn filter_targets( - allowed_targets: &mut Vec<Target>, - target_group: &'static [Target], - target_group_name: &'static str, - target: Target, - added_fake_targets: &mut Vec<&'static str>, -) { - if target_group.contains(&target) { - return; - } - if allowed_targets.iter().filter(|at| target_group.contains(at)).count() < 2 { - return; - } - allowed_targets.retain(|t| !target_group.contains(t)); - added_fake_targets.push(target_group_name); -} - -/// This is the list of all targets to which a attribute can be applied -/// This is used for: -/// - `rustc_dummy`, which can be applied to all targets -/// - Attributes that are not parted to the new target system yet can use this list as a placeholder -pub(crate) const ALL_TARGETS: &'static [MaybeWarn] = &[ - Allow(Target::ExternCrate), - Allow(Target::Use), - Allow(Target::Static), - Allow(Target::Const), - Allow(Target::Fn), - Allow(Target::Closure), - Allow(Target::Mod), - Allow(Target::ForeignMod), - Allow(Target::GlobalAsm), - Allow(Target::TyAlias), - Allow(Target::Enum), - Allow(Target::Variant), - Allow(Target::Struct), - Allow(Target::Field), - Allow(Target::Union), - Allow(Target::Trait), - Allow(Target::TraitAlias), - Allow(Target::Impl { of_trait: false }), - Allow(Target::Impl { of_trait: true }), - Allow(Target::Expression), - Allow(Target::Statement), - Allow(Target::Arm), - Allow(Target::AssocConst), - Allow(Target::Method(MethodKind::Inherent)), - Allow(Target::Method(MethodKind::Trait { body: false })), - Allow(Target::Method(MethodKind::Trait { body: true })), - Allow(Target::Method(MethodKind::TraitImpl)), - Allow(Target::AssocTy), - Allow(Target::ForeignFn), - Allow(Target::ForeignStatic), - Allow(Target::ForeignTy), - Allow(Target::MacroDef), - Allow(Target::Param), - Allow(Target::PatField), - Allow(Target::ExprField), - Allow(Target::WherePredicate), - Allow(Target::MacroCall), - Allow(Target::Crate), - Allow(Target::Delegation { mac: false }), - Allow(Target::Delegation { mac: true }), -]; - -/// Parse a single integer. -/// -/// Used by attributes that take a single integer as argument, such as -/// `#[link_ordinal]` and `#[rustc_layout_scalar_valid_range_start]`. -/// `cx` is the context given to the attribute. -/// `args` is the parser for the attribute arguments. -pub(crate) fn parse_single_integer<S: Stage>( - cx: &mut AcceptContext<'_, '_, S>, - args: &ArgParser<'_>, -) -> Option<u128> { - let Some(list) = args.list() else { - cx.expected_list(cx.attr_span); - return None; - }; - let Some(single) = list.single() else { - cx.expected_single_argument(list.span); - return None; - }; - let Some(lit) = single.lit() else { - cx.expected_integer_literal(single.span()); - return None; - }; - let LitKind::Int(num, _ty) = lit.kind else { - cx.expected_integer_literal(single.span()); - return None; - }; - Some(num.0) -} |